Technical Field

The present invention relates to a family of colorants and colorant modifiers. The colorant modifiers, according to the present invention, are capable of stabilizing a color to ordinary light and/or rendering the colorant mutable when exposed to specific wavelengths of electromagnetic radiation.

Background of the Invention

A major problem with colorants is that they tend to fade when exposed to sunlight or artificial light. It is believed that most of the fading of colorants when exposed to light is due to photodegradation mechanisms. These degradation mechanisms include oxidation or reduction of the colorants depending upon the environmental conditions in which the colorant is placed.

Fading of a colorant also depends upon the substrate upon which they reside. Product analysis of stable photoproducts and intermediates has revealed several important modes of photodecomposition. These include electron ejection from the colorant, reaction with ground-state or excited singlet state oxygen, cleavage of the central carbon-phenyl ring bonds to form amino substituted benzophenones, such as triphenylmethane dyes, reduction to form the colorless leuco dyes and electron or hydrogen atom abstraction to form radical intermediates.

Various factors such as temperature, humidity, gaseous reactants, including O2, O3, SO2, and NO2, and water soluble, nonvolatile photodegradation products have been shown to influence fading of colorants. The factors that effect colorant fading appear to exhibit a certain amount of interdependence. It is due to this complex behavior that observations for the

fading of a particular colorant on a particular substrate cannot be applied to colorants and substrates in general.

Under conditions of constant temperature it has been observed that an increase in the relative humidity of the atmosphere increases the fading of a colorant for a variety of colorant-substrate systems (e.g., McLaren, K., J. Soc.

Dyers Colour, 1956, 72, 527). For example, as the relative humidity of the atmosphere increases, a fiber may swell because the moisture content of the fiber increases. This aids diffusion of gaseous reactants through the substrate structure. The ability of a light source to cause photochemical change in a colorant is also dependent upon the spectral distribution of the light source, in particular the proportion of radiation of wavelengths most effective in causing a change in the colorant and the quantum yield of colorant degradation as a function of wavelength. On the basis of photochemical principles, it would be expected that light of higher energy (short wavelengths) would be more effective at causing fading than light of lower energy (long wavelengths). Studies have revealed that this is not always the case. Over 100 colorants of different classes were studied and found that generally the most unstable were faded more efficiently by visible light while those of higher lightfastness were degraded mainly by ultraviolet light (McLaren, K„ J. Soc. Dyers Colour, 1956, 72, 86).

The influence of a substrate on colorant stability can be extremely important. Colorant fading may be retarded or promoted by some chemical group within the substrate. Such a group can be a ground-state species or an excited-state species. The porosity of the substrate is also an important factor in colorant stability. A high porosity can promote fading of a colorant by facilitating penetration of moisture and gaseous reactants into the substrate. A substrate may also act as a protective agent by screening the colorant from light of wavelengths capable of causing degradation.

The purity of the substrate is also an important consideration whenever the photochemistry of dyed technical polymers is considered. For example, technical-grade cotton, viscose rayon, polyethylene, polypropylene, and polyisoprene are known to contain carbonyl group impurities. These impurities absorb light of wavelengths greater than 300 nm, which are present in sunlight, and so, excitation of these impurities may lead to reactive species capable of causing colorant fading (van Beek, H.C.A., Col. Res. Appl, 1983, 8(3), 176).

Therefore, there exists a great need for methods and compositions which are capable of stabilizing a wide variety of colorants from the effects of both sunlight and artificial light

There is also a need for colorants that can be mutated, preferably from a colored to a colorless form, when exposed to a specific predetermined wavelength of electromagnetic radiation. For certain uses, the ideal colorant would be one that is stable in ordinary light and can be mutated to a colorless form when exposed to a specific predetermined wavelength of electromagnetic radiation.

Summary of the Invention

The present invention addresses the needs described above by providing compositions and methods for stabilizing colorants against radiation including radiation in the visible wavelength range. In addition, die present invention provides certain embodiments in which the light-stable colorant system is mutable by exposure to certain narrow bandwidths of radiation. In certain embodiments, the colorant system is stable in ordinary visible light and is mutable when exposed to a specific wavelength of electromagnetic radiation.

In one embodiment, the present invention provides a composition comprising a colorant which, in the presence of a radiation transorber, is mutable when exposed to a specific wavelength of radiation, while at the same time, provides light stability to the colorant when the composition is exposed to sunlight or artificial light. The radiation transorber may be any material which is adapted to absorb radiation and interact with the colorant to effect the mutation of the colorant Generally, the radiation transorber contains a photoreactor and a wavelength-specific sensitizer. The wavelength-specific sensitizer generally absorbs radiation having a specific wavelength, and therefore a specific amount of energy, and transfers the energy to the photoreactor. It is desirable that the mutation of the colorant be irreversible. The present invention also relates to colorant compositions having improved stability, wherein the colorant is associated with a modified photoreactor. It has been determined that conventional photoreactors, which normally contain a carbonyl group with a functional group on the carbon alpha to the carbonyl group, acquire the ability to stabilize colorants when the functional group on the alpha carbon is removed via dehydration.

Accordingly, the present invention also includes a novel method of dehydrating photoreactors that have a hydroxyl group in the alpha position to a carbonyl group. This reaction is necessary to impart the colorant stabilizing capability to the photoreactor. The novel method of dehydrating photoreactors that have a hydroxyl group in the alpha position to a carbonyl group can be used with a wide variety of photoreactors to provide the colorant stabilizing capability to the photoreactor. TTie resulting modified photoreactor can optionally be linked to wavelength-selective sensitizer to impart the capability of decolorizing a colorant when exposed to a predetermined narrow wavelength of electromagnetic radiation. Accordingly, the present invention provides a photoreactor capable of stabilizing a colorant that it is admixed with.

In certain embodiments of the present invention, the mixture of colorant and radiation transorber is mutable upon exposure to radiation. In this embodiment, the photoreactor may or may not be modified as described above to impart stability when admixed to a colorant. In one embodiment, an ultraviolet radiation transorber is adapted to absorb ultraviolet radiation and interact with the colorant to effect the irreversible mutation of the colorant. It is desirable that the ultraviolet radiation transorber absorb ultraviolet radiation at a wavelength of from about 4 to about 300 nanometers. It is even more desirable that the ultraviolet radiation transorber absorb ultraviolet radiation at a wavelength of 100 to 300 nanometers. The colorant in combination with the ultraviolet radiation transorber remains stable when exposed to sunlight or artificial light If the photoreactor is modified as described above, the colorant has improved stability when exposed to sunlight or artificial light. Another stabilizer that is considered part of the present invention is an arylketoalkene having the following general formula:

wherein R. is hydrogen, an alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;

R is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;

R ₃ is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group; and

R ₄ is an aryl, heteroaryl, or substituted aryl group. Preferably, the alkene group is in the trans configuration.

Desirably, the arylketoalkene stabilizing compound has the following formula.

which efficiently absorbs radiation having a wavelength at about 308 nanometers, or

which efficiently absorbs radiation having a wavelength at about 280 nanometers. Desirably, arylketoalkene stabilizing compound of the present invention is in the trans configuration with respect to the double bond.

However, the sensitizer may also be in the cis configuration across the double bond.

Accordingly, this embodiment of the present invention provides a stabilizing molecule, the above arylketoalkene, which when associated with a colorant, stabilizes the colorant. Therefore, the above arylketoalkene can be used as an additive to any colorant composition. For example, as the arylketoalkene compound is poorly soluble in water, it can be directly added to solvent or oil based (not water based) colorant compositions. Additionally, the arylketoalkene compound can be added to other colorant compositions that contain additives enabling the solubilization of the compound therein. Further, the arylketoalkene stabilizing compounds can be solubilized in an aqueous solution by attaching the compound to a large water soluble molecule, such as a cyclodextrin.

In another embodiment of the present invention, the colored composition of the present invention may also contain a molecular includant having a chemical structure which defines at least one cavity. The molecular includants include, but are not limited to, clathrates, zeolites, and cyclodextrins. Each of

the colorant and ultraviolet radiation transorber or modified photoreactor or arylketoalkene stabilizing compound can be associated with one or more molecular includant The includant can have multiple radiation transorbers associated therewith (see co-pending U.S. Patent Application Serial No. 08/359,670). In other embodiments, the includant can have many modified photoreactors or arylketoalkene stabilizing compounds associated therewith.

In some embodiments, the colorant is at least partially included within a cavity of the molecular includant and the ultraviolet radiation transorber or modified photoreactor or arylketoalkene stabilizer is associated with the molecular includant outside of the cavity. In some embodiments, the ultraviolet radiation transorber or modified photoreactor or arylketoalkene stabilizer is covalently coupled to the outside of the molecular includant

The present invention also relates to a method of mutating the colorant associated with the composition of the present invention. The method comprises irradiating a composition containing a mutable colorant and an ultraviolet radiation transorber with ultraviolet radiation at a dosage level sufficient to mutate the colorant. As stated above, in some embodiments the composition further includes a molecular includant In another embodiment the composition is applied to a substrate before being irradiated with ultraviolet radiation. It is desirable that the mutated colorant is stable.

The present invention is also related to a substrate having an image thereon that is formed by the composition of the present invention. The colorant in the presence of the radiation transorber or modified photoreactor or arylketoalkene compound, is more stable to sunlight or artificial light. When a molecular includant is included in the composition, the colorant is stabilized by a lower ratio of radiation transorbers to colorant

The present invention also includes a dry imaging process wherein the imaging process utilizes, for example, the following three mutable colorants: cyan, magenta, and yellow. These mutable colorants can be layered on die substrate or can be mixed together and applied as a single layer. Using, for example, laser technology with three lasers at different wavelengtiis, an image can be created by selectively "erasing" colorants. A further advantage of the present invention is that the remaining colorants are stable when exposed to ordinary light The present invention also includes a method of storing data utilizing the mutable colorant on a substrate, such as a disc. The colorant is selectively

mutated using a laser at the appropriate wavelength to provide the binary information required for storing the information. The present invention is particularly useful for this purpose because the unmutated colorant is stabilized to ordinary light by the radiation transorber and can be further stabilized by the optionally included molecular includant

The present invention also includes data processing forms for use with photo-sensing apparatus that detect the presence of indicia at indicia-receiving locations of the form. The data processing forms are composed of a sheet of carrier material and a plurality of indicia-receiving locations on the surface of the sheet The indicia-receiving locations are defined by a colored composition including a mutable colorant and a radiation transorber. The data processing forms of the present invention are disclosed in co-pending U.S. Patent

Application Serial No.08/360,501, which is incorporated herein by reference.

These and other features and advantages of the present invention will become apparent after a review of the following detailed description of the disclosed embodiments and the appended claims.

Brief Description of the Figures

Figure 1 illustrates an ultraviolet radiation transorber/ mutable colorant molecular includant complex wherein the mutable colorant is malachite green, the ultraviolet radiation transorber is IRGACURE 184 (1-hydroxycyclohexyl phenyl ketone), and the molecular includant is β-cyclodextrin.

Figure 2 illustrates an ultraviolet radiation transorber/ mutable colorant/ molecular includant complex wherein the mutable colorant is Victoria Pure Blue BO (Basic Blue 7), the ultraviolet radiation transorber is IRGACURE 184

(1-hydroxycyclohexyl phenyl ketone), and the molecular includant is β- cyclodextrin.

Figure 3 is a plot of the average number of ultraviolet radiation transorber molecules which are covalently coupled to each molecule of a molecular includant in several colored compositions, which number also is referred to by the term, "degree of substitution," versus the decolorization time upon exposure to 222-nanometer excimer lamp ultraviolet radiation.

Figure 4 is an illustration of several 222 nanometer excimer lamps arranged in four parallel columns wherein the twelve numbers represent the locations where twelve intensity measurements were obtained approximately 5.5 centimeters from the excimer lamps.

Figure 5 is an illustration of several 222 nanometer excimer lamps arranged in four parallel columns wherein the nine numbers represent the locations where nine intensity measurements were obtained approximately 5.5 centimeters from the excimer lamps.

Figure 6 is an illustration of several 222 nanometer excimer lamps arranged in four parallel columns wherein the location of the number "1" denotes the location where ten intensity measurements were obtained from increasing distances from the lamps at that location. (The measurements and their distances from the lamp are summarized in Table 12.)

Detailed Description of the Invention

The present invention relates in general to a light-stable colorant system that is optionally mutable by exposure to narrow band-width radiation. The present invention more particularly relates to a composition comprising a colorant which, in the presence of a radiation transorber, is stable under ordinary light but is mutable when exposed to specific, narrow band-width radiation. The radiation transorber is capable of absorbing radiation and interacting with the colorant to effect a mutation of the colorant The radiation transorber may be any material which is adapted to absorb radiation and interact with the colorant to effect the mutation of the colorant. Generally, the radiation transorber contains a photoreactor and a wavelength-specific sensitizer. The wavelength-specific sensitizer generally absorbs radiation having a specific wavelength, and therefore a specific amount of energy, and transfers the energy to the photoreactor. It is desirable that the mutation of the colorant be irreversible.

The present invention also relates to colorant compositions having improved stability, wherein the colorant is associated with a modified photoreactor. It has been determined that conventional photoreactors which normally contain a carbonyl group with a functional group on the carbon alpha to the carbonyl group acquire the ability to stabilize colorants when the functional group on the alpha carbon is removed. Accordingly, the present invention also includes a novel method of dehydrating photoreactors that have a hydroxyl group in the alpha position to a carbonyl group. This reaction is necessary to impart the colorant stabilizing capability to the photoreactor. The novel method of dehydrating photoreactors that have a hydroxyl group in the alpha position to a carbonyl group can be used with a wide variety of

photoreactors to provide the colorant stabilizing capability to the photoreactor. The resulting modified photoreactor can optionally be linked to a wavelength- selective sensitizer to impart the capability of decolorizing a colorant when exposed to a predetermined narrow wavelength of electromagnetic radiation. Accordingly, d e present invention provides a photoreactor capable of stabilizing a colorant with which it is admixed.

In certain embodiments of the present invention, the colorant and radiation transorber is mutable upon exposure to radiation. In this embodiment the photoreactor may or may not be modified as described above to impart stability when admixed to a colorant. In one embodiment, an ultraviolet radiation transorber is adapted to absorb ultraviolet radiation and interact with the colorant to effect the irreversible mutation of the colorant It is desirable that the ultraviolet radiation transorber absorb ultraviolet radiation at a wavelength of from about 4 to about 300 nanometers. If the photoreactor in the radiation transorber is modified as described above, the colorant has improved stability when exposed to sunlight or artificial light

The present invention also relates to a method of mutating the colorant in the composition of the present invention. The method comprises irradiating a composition containing a mutable colorant and a radiation transorber with radiation at a dosage level sufficient to mutate the colorant

The present invention further relates to a method of stabilizing a colorant comprising associating the modified photoreactor described above with the colorant Optionally, the photoreactor may be associated with a wavelength- selective sensitizer, or the photoreactor may be associated with a molecular includant, or both.

Thus, the stabilizing composition produced by the process of dehydrating a tertiary alcohol that is alpha to a carbonyl group on a photoreactor is shown in the following general formula:

wherein R is hydrogen, an alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;

R. is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;

R ₃ is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group; and

R ₄ is an aryl, heteroaryl, or substituted aryl group. Preferably, the alkene group is in the trans configuration.

Desirably, the arylketoalkene stabilizing compound is represented by die following formulas:

or

Accordingly, this embodiment of the present invention provides a stabilizing molecule, the above arylketoalkene, which when associated with a colorant, stabilizes the colorant Therefore, the above arylketoalkene can be used as an additive to any colorant composition. For example, as the arylketoalkene compound is not water soluble, it can be direcdy added to solvent or oil based (not water based) colorant compositions. Additionally, the arylketoalkene compound can be added to other colorant compositions that contain additives enabling the solubilization of the compound therein. Further, die arylketoalkene stabilizing compounds can be solubilized in an aqueous solution by attaching the compound to a large water soluble molecule, such as a cyclodextrin.

After definitions of various terms used herein, the mutable colorant composition of the present invention and methods for making and using that composition are described in detail, followed by a detailed description of the improved Ught stable composition of the present invention and methods for making the improved light stable compositions.

Definitions

The term "composition" and such variations as "colored composition" are used herein to mean a colorant, and a radiation transorber or a modified photoreactor or an arylketoalkene stabilizer. Where the colored composition includes the modified photoreactor, it may further comprise a wavelength- selective sensitizer. Where the colored composition includes d e arylketoalkene stabilizer, it may further comprise a photoreactor. When reference is being made to a colored composition which is adapted for a specific application, the term "composition-based" is used as a modifier to indicate that die material includes a colorant, an ultraviolet radiation transorber or a modified photoreactor or an arylketoalkene stabilizer, and, optionally, a molecular includant

As used herein, d e term "colorant" is meant to include, without limitation, any material which typically will be an organic material, such as an organic colorant or pigment Desirably, the colorant will be substantially transparent to, that is, will not significandy interact with, the ultraviolet radiation to which it is exposed. The term is meant to include a single material or a mixture of two or more materials.

As used herein, die term "irreversible" means that the colorant will not revert to its original color when it no longer is exposed to ultraviolet radiation.

The term "radiation transorber" is used herein to mean any material which is adapted to absorb radiation at a specific wavelength and interact with the colorant to affect the mutation of the colorant and, at the same time, protect the colorant from fading in sunlight or artificial light. The term "ultraviolet radiation transorber" is used herein to mean any material which is adapted to absorb ultraviolet radiation and interact with the colorant to effect the mutation of the colorant. In some embodiments, the ultraviolet radiation transorber may be an organic compound. Where die radiation transorber is comprised of a wavelength-selective sensitizer and a photoreactor, the photoreactor may optionally be modified as described below.

The term "compound" is intended to include a single material or a mixture of two or more materials. If two or more materials are employed, it is not necessary that all of them absorb radiation of the same wavelength. As discussed more fully below, a radiation transorber is comprised of a photoreactor and a wavelength selective sensitizer. The radiation transorber has

die additional property of making the colorant with which the radiation transorber is associated light stable to sunlight or artificial light

The term "light-stable" is used herein to mean that the colorant, when associated with the radiation transorber or modified photoreactor or arylketoalkene stabilizer molecule, is more stable to light, including, but not limited to, sunlight or artificial light, than when the colorant is not associated with these compounds.

The term "molecular includant," as used herein, is intended to mean any substance having a chemical structure which defines at least one cavity. That is, the molecular includant is a cavity-containing structure. As used herein, the term "cavity" is meant to include any opening or space of a size sufficient to accept at least a portion of one or both of the colorant and the ultraviolet radiation transorber.

The term "functionalized molecular includant" is used herein to mean a molecular includant to which one or more molecules of an ultraviolet radiation transorber or modified photoreactor or arylketoalkene stabilizer are covalendy coupled to each molecule of the molecular includant The term "degree of substitution" is used herein to refer to the number of these molecules or leaving groups (defined below) which are covalendy coupled to each molecule of the molecular includant

The term "derivatized molecular includant" is used herein to mean a molecular includant having more than two leaving groups covalendy coupled to each molecule of molecular includant The term "leaving group" is used herein to mean any leaving group capable of participating in a bimolecular nucleophilic substitution reaction.

The term "artificial Ught" is used herein to mean Ught having a relatively broad bandwidth that is produced from conventional Ught sources, including, but not limited to, conventional incandescent light bulbs and fluorescent Ught bulbs. The term "ultraviolet radiation" is used herein to mean electromagnetic radiation having wavelengths in the range of from about 4 to about 400 nanometers. The especiaUy desirable ultraviolet radiation range for the present invention is between approximately 100 to 375 nanometers. Thus, the term includes the regions commonly referred to as ultraviolet and vacuum ultraviolet The wavelength ranges typically assigned to these two regions are from about

180 to about 400 nanometers and from about 100 to about 180 nanometers, respectively.

The term "thereon" is used herein to mean thereon or therein. For example, the present invention includes a substrate having a colored composition thereon. According to the definition of "thereon" the colored composition may be present on the substrate or it may be in the substrate.

The term "mutable," with reference to the colorant, is used to mean that the absorption maximum of die colorant in the visible region of the electromagnetic spectrum is capable of being mutated or changed by exposure to radiation, preferably ultraviolet radiation, when in the presence of the radiation transorber. In general, it is only necessary that such absorption maximum be mutated to an absorption maximum which is different from that of the colorant prior to exposure to the ultraviolet radiation, and that the mutation be irreversible. Thus, the new absorption maximum can be within or outside of die visible region of the electromagnetic spectrum. In other words, the colorant can mutate to a different color or be rendered colorless. Hie latter is also desirable when die colorant is used in data processing forms for use with photo-sensing apparatus that detect the presence of indicia at indicia-receiving locations of die form.

Functionalized Molecular Includant

In several embodiments, d e radiation transorber molecule, the wavelength-selective sensitizer, the photoreactor, or the arylketoalkene stabilizer may be associated with a molecular includant It is to be noted that in all the formulas, the number of such molecules can be between approximately 1 and approximately 21 molecules per molecular includant Of course, in certain situations, there can be more than 21 molecules per molecular includant molecule. Desirably, there are more than three of such molecules per molecular includant The degree of substitution of the functionalized molecular includant may be in a range of from 1 to approximately 21. As another example, the degree of substitution may be in a range of from 3 to about 10. As a further example, the degree of substitution may be in a range of from about 4 to about 9.

The colorant is associated with the functionaUzed molecular includant The term "associated" in its broadest sense means that the colorant is at least in close proximity to the functionaUzed molecular includant For example, the

colorant may be maintained in close proximity to the functionalized molecular includant by hydrogen bonding, van der Waals forces, or the like. Alternatively, die colorant may be covalendy bonded to the functionalized molecular includant, although this normally is neither desired nor necessary. As a further example, the colorant may be at least partially included within the cavity of the functionalized molecular includant

The examples below disclose methods of preparing and associating these colorants and ultraviolet radiation transorbers to b-cyclodextrins. For illustrative purposes only, Examples 1, 2, 6, and 7 disclose one or more methods of preparing and associating colorants and ultraviolet radiation transorbers to cyclodextrins.

In those embodiments of the present inveniton in which the ultraviolet radiation transorber is covalendy coupled to the molecular includant, die efficiency of energy transfer from the ultraviolet radiation transorber to die colorant is, at least in part, a function of the number of ultraviolet radiation transorber molecules which are attached to d e molecular includant. It now is known that die syntiietic methods described above result in covalendy coupling an average of two transorber molecules to each molecule of the molecular includant Because the time required to mutate the colorant should, at least in part, be a function of die number of ultraviolet radiation transorber molecules coupled to each molecule of molecular includant there is a need for an improved colored composition in which an average of more than two ultraviolet radiation transorber molecules are covalendy coupled to each molecule of the molecular includant. Accordingly, die present invention also relates to a composition which includes a colorant and a functionalized molecular includant. For Ulustrative purposes only, Examples 12 through 19, and 21 through 22 disclose otiier methods of preparing and associating colorants and ultraviolet radiation transorbers to cyclodextrins, wherein more than two molecules of the ultraviolet radiation transorber are covalendy coupled to each molecule of the molecular includant Further, Examples 29 and 31 disclose methods of preparing and associating arylketoalkene stabihzers with cyclodextrin, wherein the cyclodextrin has an average of approximately 3 or 4 stabilizer molecules attached thereto. The present invention also provides a method of making a functionalized molecular includant. The method of making a functionalized molecular

includant involves the steps of providing a denvatized ultraviolet radiation transorber having a nucleophihc group, providing a derivatized molecular includant having more than two leaving groups per molecule, and reacting the derivatized ultraviolet radiation transorber with the derivatized molecular includant under conditions sufficient to result in the covalent coupling of an average of more than two ultraviolet radiation transorber molecules to each molecular includant molecule. By way of example, the derivatized ultraviolet radiation transorber may be 2-[p-(2-metiιyl-2- mercaptomethylpropionyl)phenoxy]ethyl 1 ,3-dioxo-2-isoindoline-acetate. As another example, the derivatized ultraviolet radiation transorber may be 2- mercaptomethyl-2-methyl-4 ^, -[2-(p-(3- oxobutyl)phenoxy]ethoxy]propiophenone.

In general, the derivatized ultraviolet radiation transorber and die derivatized molecular includant are selected to cause the covalent coupling of the ultraviolet radiation transorber to the molecular includant by means of a bimolecular nucleophihc substitution reaction. Consequendy, the choice of die nucleophihc group and die leaving groups and d e preparation of d e derivatized ultraviolet radiation transorber and derivatized molecular includant respectively, may be readily accomplished by those having ordinary skill in the art without the need for undue experimentation.

The nucleophihc group of the derivatized ultraviolet radiation transorber may be any nucleophihc group capable of participating in a bimolecular nucleophihc substitution reaction, provided, of course, that d e reaction results in the covalent coupling of more than two molecules of the ultraviolet radiation transorber to the molecular includant The nucleophihc group generally will be a Lewis base, i.e., any group having an unshared pair of electrons. The group may be neutral or negatively charged. Examples of nucleophihc groups include, by way of iUustration only, ahphatic hydroxy, aromatic hydroxy, alkoxides, carboxy, carboxylate, amino, and mercapto. Similarly, the leaving group of die derivatized molecular includant may be any leaving group capable of participating in a bimolecular nucleophihc substitution reaction, again provided that the reaction results in the covalent coupling of more than two molecules of the ultraviolet radiation transorber to the molecular includant Examples of leaving groups include, also by way of iUustration only, -toluenesulfonates (tosylates), p-bromobenzenesulfonates

(brosylates), /Mutrobenzenesulfbnates (nosylates), methanesulfonates

(mesylates), oxonium ions, alkyl perchlorates, ammonioalkane sulfonate esters (betylates), alkyl fluorosulfonates, trifluoromethanesulfonates (triflates), nonafiuorobutanesulfonates (nonaflates), and 2,2,2-trifluoroethanesulfonates (tresylates). The reaction of the derivatized ultraviolet radiation transorber with the derivatized molecular includant is carried out in solution. The choice of solvent depends upon die solubiUties of the two derivatized species. As a practical matter, a particularly useful solvent is N,N-dimethylformamide (DMF).

The reaction conditions, such as temperature, reaction time, and die like generally are matters of choice based upon d e natures of the nucleophihc and leaving groups. Elevated temperatures usually are not required. For example, the reaction temperature may be in a range of from about 0°C to around ambient temperature, i.e., to 20°-25°C.

The preparation of d e functionalized molecular includant as described above geneπdly is carried out in the absence of the colorant. However, the colorant may be associated with die derivatized molecular includant before reacting the derivatized ultraviolet radiation transorber with the derivatized molecular includant, particularly if a degree of substitution greater tiian about three is desired. When the degree of substitution is about three, it is beheved diat the association of the colorant with the functionalized molecular includant stiU may permit the colorant to be at least partiaUy included in a cavity of the functionaUzed molecular includant At higher degrees of substitution, such as about six, steric hindrance may partially or completely prevent the colorant from being at least partiaUy included in a cavity of the functionalized molecular includant Consequentiy, the colorant may be associated witii die derivatized molecular includant which normally will exhibit Utde, if any, steric hindrance. In this instance, the colorant will be at least partiaUy included in a cavity of the derivatized molecular includant. The above-described bimolecular nucleophihc substitution reaction then may be carried out to give a colored composition of die present invention in which the colorant is at least partiaUy included in a cavity of die functionalized molecular includant.

Mutable Compositions

As stated above, die present invention provides compositions comprising a colorant which, in the presence of a radiation transorber, is mutable when exposed to a specific wavelength of radiation, while at the same

time, provides Ught stabiUty to the colorant with respect to sunUght and artificial Ught Desirably, the mutated colorant wiU be stable, i.e., not appreciably adversely affected by radiation normaUy encountered in the environment, such as natural or artificial Ught and heat Thus, desirably, a colorant rendered colorless wiU remain colorless indefinitely.

The dye, for example, may be an organic dye. Organic dye classes include, by way of iUustration only, triarylraethyl dyes, such as Malachite Green Carbinol base {4-(dimethylammo)-a-[4-(dime_hylamino)phenyl]-a- phenylbenzene-methanol}, Malachite Green Carbinol hydrochloride {N-4-[[4- (dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexyldien- 1 -yUdene]-N- methyl-methanaminium chloride or bis[p-

(dimedιylamino)phenyl]phenylmethylium chloride}, and Malachite Green oxalate { N-4-[[4-(dimethylamino)phenyl]phenylmethylene]-2,5-cyclo- hexyldien-l-yUdene]-N-methylme_hanaminium chloride or bis[p-(dimethyl- amino)phenyl]phenylmethyUum oxalate}; monoazo dyes, such as Cyanine

Black, Chrysoidine [Basic Orange 2; 4-(phenylazo)-l,3-benzenediamine monohydrochloride], Victoria Pure Blue BO, Victoria Pure Blue B, basic fuschin and β-Naphd ol Orange; thiazine dyes, such as Methylene Green, zinc chloride double salt [3,7-bis(dimemy_amino)-6-nitrophenothiazin-5-ium chloride, zinc chloride double salt]; oxazine dyes, such as Lumichrome (7,8- dimethylalloxazine); naphthalimide dyes, such as Lucifer YeUow CH (6-amino- 2-[(hydrazinocarbonyl)amino]-2,3-dihydro-l,3-dioxo-lH- benz[de]isoquinoline-5,8-disulfonic acid diUthium salt}; azine dyes, such as Janus Green B {3-(diedιylamino)-7-[[4-(dimethylamino)phenyl]azo]-5- phenylphenazinium chloride}; cyanine dyes, such as Indocyanine Green

{ Cardio-Green or Fox Green; 2-[7-[ 1 ,3-dihydro- 1 , 1 -dimethyl-3-(4-sulfobutyl)- 2H-benz[e] indol-2-yhdene]- 1 ,3,5-heptatrienyl]- 1 , 1 -dimethyl-3-(4-sulfobutyl)- lH-benz[e]indoUum hydroxide inner salt sodium salt}; indigo dyes, such as Indigo {Indigo Blue or Vat Blue 1; 2-(l,3-dihydro-3-oxo-2H-indol-2-ylidene)- l,2-dihydro-3H-indol-3-one}; coumarin dyes, such as 7-hydroxy-4- methylcoumarin (4-methylumbeUiferone); benzimidazole dyes, such as Hoechst 33258 [bisbenzimide or 2-(4-hydroxyphenyl)-5-(4-methyl-l-piperazinyl)-2,5- bi-lH-benzimidazole trihydrochloride pentahydrate]; paraquinoidal dyes, such as Hematoxylin {Natural Black 1; 7,l lb-dihydrobenz[b]indeno[l,2-d]pyran- 3,4,6a,9,10(6H)-pentol}; fluorescein dyes, such as Fluoresceinamine (5- aminofluorescein); diazonium salt dyes, such as Diazo Red RC (Azoic Diazo

No. 10 or Fast Red RC salt; 2-medιoxy-5-chlorobenzenediazonium chloride, zinc chloride double salt); azoic diazo dyes, such as Fast Blue BB salt (Azoic Diazo No. 20; 4-benzoylamino-2,5-diethoxybenzene diazonium chloride, zinc chloride double salt); phenylenediamine dyes, such as Disperse YeUow 9 [N- (2,4-dinitrophenyl)-l,4-phenylenediamine or Solvent Orange 53]; diazo dyes, such as Disperse Orange 13 [Solvent Orange 52; l-phenylazo-4-(4- hydroxyphenylazo)naphthalene]; anthraquinone dyes, such as Disperse Blue 3 [CelUton Fast Blue FFR; l-methylamino-4-(2-hydroxyethylamino)-9,10- anthraquinone], Disperse Blue 14 [CelUton Fast Blue B; l,4-bis(methylamino)- 9,10-anthraquinone], and Alizarin Blue Black B (Mordant Black 13); trisazo dyes, such as Direct Blue 71 {Benzo Light Blue FFL or Sirius Light Blue BRR; 3-[(4-[(4-[(6-amino-l-hydroxy-3-sulfo-2-naphthalenyl)azo]-6- sulfo-l- naphthalenyl)azo]- l-naphthalenyl)azo]- 1 ,5-naphthalenedisulfonic acid tetrasodium salt}; xanthene dyes, such as 2,7-dichlorofluorescein; proflavine dyes, such as 3,6-diaminoacridine hemisulfate (Proflavine); sulfonaphtiialein dyes, such as Cresol Red (o-cresolsulfonaphthalein); phthalocyanine dyes, such as Copper Phthalocyanine {Pigment Blue 15; (SP-4-l)-[29H,31H- phthalocyanato(2-)-N ²⁹ ,N ³⁰ ,N ³¹ ,N ³ ]copper}; carotenoid dyes, such as trans-β- carotene (Food Orange 5); carminic acid dyes, such as Carmine, the aluminum or calcium-aluminum lake of carminic acid (7-a-D-glucopyranosyl-9,10- dihydro-3,5,6,8-tetrahydroxy-l-methyl-9,10-dioxo-2-anthracen ecarbonyUc acid); azure dyes, such as Azure A [3-amino-7-(dimethylamino)phenothiazin-5- ium chloride or 7-(dimedιylamino)-3-imino-3H-phenothiazine hydrochloride]; and acridine dyes, such as Acridine Orange [Basic Orange 14; 3,8- bis(dimethylamino)acridine hydrochloride, zinc chloride double salt] and

Acriflavine (Acriflavine neutral; 3,6-diamino-lO-medιylacridinium chloride mixture with 3,6-acridinediamine).

The present invention includes unique compounds, namely, radiation transorbers, that are capable of absorbing narrow ultraviolet wavelength radiation, while at die same time, imparting Ught-stabiUty to a colorant with which the compounds are associated. The compounds are synthesized by combining a wavelength-selective sensitizer and a photoreactor. The photoreactors oftentimes do not efficiendy absorb high energy radiation. When combined with the wavelength-selective sensitizer, the resulting compound is a wavelength specific compound that efficiendy absorbs a very narrow spectrum

of radiation. The wavelength-selective sensitizer may be covalendy coupled to the photoreactor.

By way of example, the wavelength-selective sensitizer may be selected from die group consisting of phthaloylglycine and 4-(4-oxyphenyl)-2-butanone. As another example, die photoreactor may be selected from the group consisting of l-[4-(2-hydroxyethoxy)pheny-]-2-hydroxy-2-metiiylpropan-l-on e and cyclohexyl-phenyl ketone ester. Other photoreactors are listed by way of example, in the detailed description below regarding d e impoved stabilized composition of the present invention. As a further example, the ultraviolet radiation transorber may be 2-[p-2-methyllactoyl)phenoxy]ethyl l,3-dioxo-2- isoin-dolineacetate. As stiU another example, the ultraviolet radiation transorber may be 2-hydroxy-2-methyl-4'-2-[p-(3-oxobutyl)phenoxy]propiophenone .

Although die colorant and the ultraviolet radiation transorber have been described as separate compounds, they can be part of the same molecule. For example, they can be covalendy coupled to each other, either direcdy, or indirecdy through a relatively smaU molecule, or spacer. Alternatively, d e colorant and ultraviolet radiation transorber can be covalendy coupled to a large molecule, such as an oUgomer or a polymer. Further, die colorant and ultraviolet radiation transorber may be associated with a large molecule by van der Waals forces, and hydrogen bonding, among other means. Other variations wiU be readily apparent to those having ordinary skiU in the art

For example, in an embodiment of the composition of d e present invention, the composition further comprises a molecular includant Thus, the cavity in the molecular includant can be a tunnel through die molecular includant or a cave-like space or a dented-in space in the molecular includant The cavity can be isolated or independent or connected to one or more other cavities.

The molecular includant can be inorganic or organic in nature. In certain embodiments, the chemical structure of the molecular includant is adapted to form a molecular inclusion complex. Examples of molecular includants are, by way of iUustration only, clathrates or intercalates, zeolites, and cyclodextrins.

Examples of cyclodextrins include, but are not limited to, a-cyclodextrin, b- cyclodextrin, g-cyclodextrin, hydroxypropyl b-cyclodextrin, hydroxyethyl b- cyclodextrin, sulfated b-cyclodextrin, hydroxyethyl a cyclodextrin, carboxymethyle a cyclodextrin, carboxymethyl b cyclodextrin, carboxymethyl g cyclodextrin, octyl succinated a cyclodextrin, octyl succinated b cyclodextrin,

octyl succinated g cyclodextrin and sulfated b and g-cyclodextrin (American Maize-Products Company, Hammond, Indiana).

The desired molecular includant is a-cyclodextrin. More particularly, in some embodiments, the molecular includant is an a-cyclodextrin. In other embodiments, d e molecular includant is a b-cyclodextrin. Although not wanting to be bound by die foUowing theory, it is beUeved tiiat the closer die transorber molecule is to the mutable colorant on the molecular includant die more efficient the interaction with die colorant to effect mutation of the colorant. Thus, the molecular includant with functional groups that can react with and bind die transorber molecule and that are close to the binding site of the mutable colorant are the more desirable molecular includants.

In some embodiments, die colorant and d e ultraviolet radiation transorber are associated witii the molecular includant The term "associated", in its broadest sense, means that the colorant and the ultraviolet radiation transorber are at least in close proximity to the molecular includant For example, the colorant and/or d e ultraviolet radiation transorber can be maintained in close proximity to the molecular includant by hydrogen bonding, van der Waals forces, or the like. Alternatively, either or both of the colorant and die ultraviolet radiation transorber can be covalendy bonded to d e molecular includant In certain embodiments, die colorant wiU be associated with the molecular includant by means of hydrogen bonding and/or van der Waals forces or the like, whde the ultraviolet radiation transorber is covalendy bonded to the molecular includant. In other embodiments, the colorant is at least partiaUy included within the cavity of the molecular includant, and the ultraviolet radiation transorber is located outside of die cavity of the molecular includant

In one embodiment wherein die colorant and die ultraviolet radiation transorber are associated with the molecular includant, die colorant is crystal violet, the ultraviolet radiation transorber is a dehydrated phdιaloylglycine-2959, and die molecular includant is b-cyclodextrin. In yet another embodiment wherein the colorant and die ultraviolet radiation transorber are associated with the molecular includant, the colorant is crystal violet, the ultraviolet radiation transorber is 4(4-hydroxyphenyl) butan-2-one-2959 (chloro substituted), and the molecular includant is b-cyclodextrin.

In another embodiment wherein the colorant and die ultraviolet radiation transorber are associated witii die molecular includant, die colorant is malachite green, the ultraviolet radiation transorber is IRGACURE 184, and the molecular

includant is b-cyclodextrin as shown in Figure 1. In stiU another embodiment wherein the colorant and d e ultraviolet radiation transorber are associated with d e molecular includant, the colorant is Victoria Pure Blue BO, the ultraviolet radiation transorber is IRGACURE 184, and die molecular includant is b- cyclodextrin as shown in Figure 2.

The present invention also relates to a method of mutating the colorant in the composition of the present invention. Briefly described, die method comprises irradiating a composition containing a mutable colorant and a radiation transorber with radiation at a dosage level sufficient to mutate the colorant As stated above, in one embodiment the composition further includes a molecular includant In anotiier embodiment die composition is appUed to a substrate before being irradiated with ultraviolet radiation. The composition of the present invention may be irradiated with radiation having a wavelength of between about 4 to about 1,000 nanometers. The radiation to which the composition of the present invention is exposed gene aUy wiU have a wavelength of from about 4 to about 1,000 nanometers. Thus, the radiation may be ultraviolet radiation, including near ultraviolet and far or vacuum ultraviolet radiation; visible radiation; and near infrared radiation. Desirably, the composition is irradiated with radiation having a wavelength of from about 4 to about 700 nanometers. More desirably, he composition of die present invention is irradiated with ultraviolet radiation having a wavelength of from about 4 to about 400 nanometers. It is more desirable that the radiation has a wavelength of between about 100 to 375 nanometers.

EspeciaUy desirable radiation is incoherent pulsed ultraviolet radiation produced by a dielectric barrier discharge lamp. Even more preferably, the dielectric barrier discharge lamp produces radiation having a narrow bandwidth, i.e., d e half width is of d e order of approximately 5 to 100 nanometers. Desirably, the radiation wiU have a half width of the order of approximately 5 to 50 nanometers, and more desirably will have a half width of the order of 5 to 25 nanometers. Most desirably, die half width wiU be of the order of approximately 5 to 15 nanometers.

The amount or dosage level of ultraviolet radiation that die colorant of the present invention is exposed to will generaUy be that amount which is necessary to mutate the colorant The amount of ultraviolet radiation necessary to mutate the colorant can be determined by one of ordinary skiU in the art using routine experimentation. Power density is die measure of the amount of

radiated electromagnetic power traversing a unit area and is usuaUy expressed in

2 watts per centimeter squared (W/cm ). The power density level range is

2 2 between approximately 5 mW/cm and 15 mW/cm , more particularly 8 to 10

2 mW/cm . The dosage level, in turn, typicaUy is a function of die time of exposure and die intensity or flux of the radiation source which irradiates die colored composition. The latter is affected by the distance of the composition from the source and, depending upon die wavelengdi range of the ultraviolet radiation, can be affected by die atmosphere between the radiation source and die composition. Accordingly, in some instances it may be appropriate to expose the composition to the radiation in a controlled atmosphere or in a vacuum, although in general neither approach is desired.

With regard to die mutation properties of the present invention, photochemical processes involve the absorption of Ught quanta, or photons, by a molecule, e.g., die ultraviolet radiation transorber, to produce a highly reactive electronically excited state. However, the photon energy, which is proportional to the wavelength of the radiation, cannot be absorbed by die molecule unless it matches the energy difference between the unexcited, or original, state and an excited state. Consequentiy, while the wavelengdi range of the ultraviolet radiation to which die colored composition is exposed is not direcdy of concern, at least a portion of the radiation must have wavelengtiis which wiU provide die necessary energy to raise die ultraviolet radiation transorber to an energy level which is capable of interacting with d e colorant.

It foUows, then, that die absorption maximum of the ultraviolet radiation transorber ideaUy wiU be matched witii die wavelengdi range of the ultraviolet radiation to increase the efficiency of the mutation of the colorant. Such efficiency also wiU be increased if the wavelength range of the ultraviolet radiation is relatively narrow, with the maximum of the ultraviolet radiation transorber coming within such range. For these reasons, especiaUy suitable ultraviolet radiation has a wavelength of from about 100 to about 375 nanometers. Ultraviolet radiation within this range desirably may be incoherent, pulsed ultraviolet radiation from a dielectric barrier discharge excimer lamp.

The term "incoherent, pulsed ultraviolet radiation" has reference to die radiation produced by a dielectric barrier discharge excimer lamp (referred to hereinafter as "excimer lamp"). Such a lamp is described, for example, by U . Kogelschatz, "SUent discharges for die generation of ultraviolet and vacuum

ultraviolet excimer radiation," Pure & Appl. Chem., 62, No. 9, pp. 1667-1674 (1990); and E. EUasson and U. Kogelschatz, "UV Excimer Radiation from Dielectric-Barrier Discharges," Appl. Phys. B, 46, pp. 299-303 (1988). Excimer lamps were developed originaUy by ABB Infocom Ltd., Lenzburg, Switzerland. The excimer lamp technology since has been acquired by Haraus

NobleUght AG, Hanau, Germany.

The excimer lamp emits radiation having a very narrow bandwidth, i.e., radiation in which the half width is of d e order of 5-15 nanometers. This emitted radiation is incoherent and pulsed, d e frequency of d e pulses being dependent upon the frequency of the alternating current power supply which typicaUy is in the range of from about 20 to about 300 kHz. An excimer lamp typicaUy is identified or referred to by the wavelength at which d e maximum intensity of the radiation occurs, which convention is foUowed throughout this specification. Thus, in comparison with most other commerciaUy useful sources of ultraviolet radiation which typicaUy emit over the entire ultraviolet spectrum and even into the visible region, excimer lamp radiation is substantiaUy monochromatic.

Excimers are unstable molecular complexes which occur only under extreme conditions, such as those temporarily existing in special types of gas discharge. Typical examples are the molecular bonds between two rare gaseous atoms or between a rare gas atom and a halogen atom. Excimer complexes dissociate within less than a microsecond and, while they are dissociating, release their binding energy in the form of ultraviolet radiation. Known excimers, in general, emit in the range of from about 125 to about 360 nanometers, depending upon d e excimer gas mixture.

For example, in one embodiment die colorant of the present invention is mutated by exposure to 222 nanometer excimer lamps. More particularly, the colorant crystal violet is mutated by exposure to 222 nanometer lamps. Even more particularly, the colorant crystal violet is mutated by exposure to 222 nanometer excimer lamps located approximately 5 to 6 centimeters from the colorant, wherein the lamps are arranged in four paraUel columns approximately 30 centimeters long. It is to be understood that the arrangement of the lamps is not critical to this aspect of the invention. Accordingly, one or more lamps may be arranged in any configuration and at any distance which results in the colorant mutating upon exposure to the lamp's ultraviolet radiation. One of ordinary skiU in the art would be able to determine by routine experimentation

which configurations and which distances are appropriate. Also, it is to be understood that different excimer lamps are to be used widi different ultraviolet radiation transorbers. The excimer lamp used to mutate a colorant associated wid an ultraviolet radiation transorber should produce ultraviolet radiation of a wavelength that is absorbed by d e ultraviolet radiation transorber.

In some embodiments, the molar ratio of ultraviolet radiation transorber to colorant generally wiU be equal to or greater than about 0.5. As a general rule, the more efficient die ultraviolet radiation transorber is in absorbing die ultraviolet radiation and interacting with, i.e., transferring absorbed energy to, d e colorant to effect irreversible mutation of the colorant, the lower such ratio can be. Current theories of molecidar photo chemistry suggest that die lower limit to such ratio is 0.5, based on die generation of two free radicals per photon. As a practical matter, however, ratios higher than 1 are likely to be required, perhaps as high as about 10. However, the present invention is not bound by any specific molar ratio range. The important feature is that the transorber is present in an amount sufficient to effect mutation of die colorant.

While the mechanism of die interaction of die ultraviolet radiation transorber widi die colorant is not totaUy understood, it is believed tiiat it may interact widi die colorant in a variety of ways. For example, the ultraviolet radiation transorber, upon absorbing ultraviolet radiation, may be converted to one or more free radicals which interact with the colorant. Such free radical- generating compounds typicaUy are hindered ketones, some examples of which include, but are not limited to: benzildimethyl ketal (avadable commercially as IRGACURE 651, Ciba-Geigy Corporation, Hawthorne, New York); 1- hydroxycyclohexyl phenyl ketone (IRGACURE 500); 2-methyl-l-[4-

(methylthio)phenyl]-2-mo hoUno-propan-l-one] (IRGACURE 907); 2-benzyl- 2-dimethylamino-l-(4-moφholinophenyl)butan-l-one (IRGACURE 369); and 1-hydroxycyclohexyl phenyl ketone (IRGACURE 184).

Alternatively, the ultraviolet radiation may initiate an electron transfer or reduction-oxidation reaction between the ultraviolet radiation transorber and die colorant. In this case, the ultraviolet radiation transorber may be, but is not limited to, Michler's ketone (p-dimethylaminophenyl ketone) or benzyl trimethyl stannate. Or, a cationic mechanism may be involved, in which case the ultraviolet radiation transorber can be, for example, bis[4- (diphenylsulphonio)phenyl)] sulfide bis-(hexafluorophosphate) (Degacure

KI85, Ciba-Geigy Corporation, Hawdiorne, New York); Cyracure UVI-6990

(Ciba-Geigy Corporation), which is a mixture of bis[4- (diphenylsulphonio)phenyl] sulfide bis(hexafluorophosphate) with related monosulphonium hexafluorophosphate salts; and n5-2,4-(cyclopentadienyl)- [ 1 ,2,3,4,5,6-n-(methylethyl)benzene] -iron(II) hexafluorophosphate (IRGACURE 261).

Stabilizing Compositions

With regard to the Ught stabilizing activity of the present invention, it has been determined that in some embodiments it is necessary to modify a conventional photoreactor to produce die improved Ught stable composition of die present invention. The simplest form of the improved Ught stable composition of the present invention includes a colorant admixed with a photoreactor modified as described below. The modified photoreactor may or may not be combined widi a wavelength-selective sensitizer. Many conventional photoreactor molecules have a functional group that is alpha to a carbonyl group. The functional group includes, but is not limited to, hydroxyl groups, ether groups, ketone groups, and phenyl groups.

For example, a preferred radiation transorber that can be used in the present invention is designated phthaloylglycine-2959 and is represented by die foUowing formula:

The photoreactor portion of the ultraviolet radiation transorber has a hydroxyl group (shaded portion) alpha to the carbonyl carbon. The above molecule does not Ught-stabUize a colorant However, the hydroxyl group can be removed by dehydration (see Example 4 and 5) yielding die following compound:

This dehydrated phtiιaloylglycine-2959 is capable of tight-stabilizing a colorant. Thus, it is beUeved that removal of the functional group alpha to die carbonyl carbon on any photoreactor molecule will impart the Ught-stabiUzing capabiUty to the molecule. WhUe the dehydrated ultraviolet radiation transorber can impart light-stabiUty to a colorant simply by mixing the molecule with the colorant, it has been found that the molecule is much more efficient at stabilizing colorants when it is attached to an includant, such as cyclodextrin, as described herein.

It is to be understood tiiat stabdization of a colorant can be accomplished according to die present invention by utilizing only die modified photoreactor.

In other words, a modified photoreactor without a wavelength selective sensitizer may be used to stabUize a colorant. An example of a photoreactor that is modified according to die present invention is DARCUR 2959. The unmodified DARCUR 2959 and the dehydrated DARCUR 2959 are shown below.

Other photoreactors can be modified according to the present invention to provide stabiUzers for dyes. These photoreactors include, but are not limited to:

1-Hydroxy-cyclohexyl-phenyl ketone ("HCPK") (IRGACURE 184, Ciba- Geigy); a,a-dimetiιoxy-a-hydroxy acetophenone (DAROCUR 1173, Merck); 1- (4-Isopropylphenyl)-2-hydroxy-2-methyl-propan- 1 -one (DAROCUR 1116,

Merck); 1 -[4-(2-Hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-propan- 1 -one (DAROCUR 2959, Merck); Poly[2-hydroxy-2-methyl-l-[4-(l- methylvinyl)phenyl] propan-1-one] (ESACURE KIP, FrateUi Lamberti); Benzoin (2-Hydroxy-l,2-diphenylethanone) (ESACURE BO, FrateUi Lamberti); Benzoin ethyl ether (2-Ethoxy-l,2-diphenylethanone) (DATTOCURE

EE, Siber Hegner); Benzoin isopropyl ether (2-Isopropoxy-l,2- diphenyledianone) (VICURE 30, Stauffer); Benzoin n-butyl ether (2-Butoxy- 1,2-diphenyledιanone) (ESACURE EB1, FrateUi Lamberti); mixture of benzoin butyl ethers (TRIGONAL 14, Akzo); Benzoin iso-butyl ether (2-Isobutoxy-l,2- diphenylethanone) (VICURE 10, Stauffer); blend of benzoin n-butyl ether and benzoin isobutyl ether (ESACURE EB3, ESACURE EB4, FrateUi Lamberti); Benzildimethyl ketal (2,2-Dimethoxy-l,2-diphenylethanone) ("BDK") (IRGACURE 651, Ciba-Geigy); 2,2-Diethoxy-l,2-diphenylethanone (UVATONE 8302, Upjohn); a,a-Diethoxyacetoρhenone (2,2-Diethoxy-l- phenyl-ethanone) ("DEAP", Upjohn), (DEAP, Rahn); and a,a -Di-(n-butoxy)- acetophenone (2,2-Dibutoxyl-l -phenyl-ethanone) (UVATONE 8301, Upjohn).

It is known to those of ordinary skiU in the art that die dehydration by conventional means of die tertiary alcohols that are alpha to the carbonyl groups is difficult One conventional reaction that can be used to dehydrate the phthaloylglycine-2959 is by reacting the phthaloylglycine-2959 in anhydrous benzene in the presence of />-toluenesulfonic acid. After refluxing the mixture, the final product is isolated. However, die yield of die desired dehydrated alcohol is only about 15 to 20% by this method.

To increase the yield of die desired dehydrated phthaloylglycine-2959, a new reaction was invented. The reaction is summarized as foUows:

xyiene

It is to be understood that the groups on die carbon alpha to the carbonyl group can be groups other than methyl groups such as aryl or heterocychc groups. The only limitation on these groups are steric timitations. Desirably, the metal salt used in the Nohr-MacDonald elimination reaction is ZnCh. It is to be understood that other transition metal salts can be used in performing the

Nohr-MacDonald elimination reaction but ZnC_2 is die preferred metal salt The amount of metal salt used in the Nohr-MacDonald elimination reaction is preferably approximately equimolar to the tertiary alcohol compound, such as the photoreactor. The concentration of tertiary alcohol in the reaction solution is between approximately 4% and 50% w/v.

Thus, die stabiUzing composition produced by die process of dehydrating a tertiary alcohol that is alpha to a carbonyl group on a photoreactor is shown in the following general formula:

wherein R. is hydrogen, an alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;

R ₂ is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;

R ₃ is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group; and

R ₄ is an aryl, heteroaryl, or substituted aryl group. Another requirement of the reaction is that it be run in a non-aqueous, non-polar solvent. The preferred solvents for running the Nohr-MacDonald elimination reaction are aromatic hydrocarbons including, but not limited to, xylene, benzene, toluene, cumene, mesitylene, p-cymene, butylbenzene, styrene, and divinylbenzene. It is to be understood that other substituted aromatic hydrocarbons can be used as solvents in the present invention, p- Xylene is the preferred aromatic hydrocarbon solvent, but other isomers of xylene can be used in performing the Nohr-MacDonald elimination reaction. An important requirement in performing the Nohr-MacDonald elimination reaction is that die reaction be run at a relatively high temperature. The reaction is desirably performed at a temperature of between approximately 80°C and 150°C. A suitable temperature for dehydrating phtiιaloylglycine-2959 is approximately 124°C. The time the reaction runs is not critical. The reaction should be run between approximately 30 minutes to 4 hours. However, depending upon die reactants and die solvent used, the timing may vary to achieve the desired yield of product.

It is to be understood that the dehydrated phtiιaloylglycine-2959 can be attached to die molecular includant in a variety of ways. In one embodiment the dehydrated phthaloylglycine-2959 is covalendy attached to die cyclodextrin as shown in the foUowing structure:

Beta-CD

In another embodiment as shown below, only the modified DARCUR

2959 without die phthaloyl glycine attached is reacted with die cyclodextrin to yield die following compound. This compound is capable of stabilizing a dye that is associated widi die molecular includant. It is to be understood that photoreactors other than DARCUR 2959 can be used in the present invention.

In yet another embodiment, the dehydrated phthaloylglycine-2959 can be attached to d e molecular includant via the opposite end of the molecule. One example of this embodiment is shown in the foUowing formula:

Anodier stabilizer that is considered part of die present invention is an arylketoalkene having the foUowing general formula:

wherein if R\ is an aryl group, then R2 is a hydrogen; heterocycUc; alkyl; aryl, or a phenyl group, the phenyl group optionaUy being substituted with an alkyl, halo, amino, or a thiol group; and if R2 is an aryl group, then R _j is hydrogen; heterocycUc; alkyl; aryl, or a phenyl group, the phenyl group optionaUy being substituted widi an alkyl, halo, amino, or a thiol group. Preferably, die alkene group is in the trans configuration.

Desirably, the arylketoalkene stabilizing compound has the following formula.

or

The arylketoalkene may also function as a wavelength-specific sensitizer in die present invention, and it may be associated widi any of the previously discussed photoreactors. One mediod of associating a photoreactor with the arylketoalkene compound of the present invention is described in Example 32. The arylketoalkene compound may optionally be covalendy bonded to die reactive species-generating photoinitiator. It is to be understood that the arylketoalkene compound of die present invention is not to be used with photoreactors in a composition where stability in natural sunUght is desired. More particularly, as the arylketoalkene compounds absorb radiation in the range of about 270 to 310 depending on the identity of R\ and R2, then these

compounds are capable of absorbing the appropriate radiation from sunUght

Accordingly, these compounds when admixed with a photoreactor can effect a mutation of the colorant upon exposure to sunlight. Where such a change in color is not desired, then a photoreactor is not to be admixed widi the arylketoalkene compound of die present invention, and die arylketoalkene compound is to be used with a colorant without a photoreactor.

In the embodiment where die arylketoalkene compound is covalendy attached to anotiier molecule, whichever Rj or R2 that is an aryl group wiU have a group including, but not limited to, a carboxyUc acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a diioalkyl group attached thereto to aUow the arylketoalkene to be covalendy bonded to the other molecule. Accordingly, the arylketoalkene stabilizing compound is represented by d e foUowing formula:

or

or

Although it is preferred that die group attached to the aryl group is para to the remainder of the stabilizer molecule, the group may also be ortho or meta to the remainder of die molecule. Accordingly, this embodiment of die present invention provides a stabiUzing arylketoalkene which, when associated widi a colorant, stabilizes the colorant Therefore, die above arylketoalkene can be used as an additive to any colorant composition. For example, as the arylketoalkene compound is not water soluble, it can be direcdy added to solvent or oU colorant compositions. AdditionaUy, the arylketoalkene compound can be added to otiier colorant

compositions that contain additives enabling die solubilization of d e compound therein.

Further, the arylketoalkene stabiUzing compounds can be solubiUzed in aqueous solution by a variety of means. One means of solubilizing the arylketoalkene stabilizing compound of die present invention is to attach the compound to a large water soluble molecule, such as a cyclodextrin, as described in Examples 28 through 31. Desirably, between about 1 and 12 arylketoalkene molecules can be attached to a cyclodextrin molecule. More desirably, between about 4 to about 9 arylketoalkene molecules are attached to a cyclodextrin molecule. Accordingly, die arylketoalkene compound attached to cyclodextrin can be added to any aqueous colorant system to stabilize the colorant therein. It is to be understood that the stabiUzing arylketoalkenes do not have to be attached to die molecular includants to exhibit their stabilizing activity. Therefore, this embodiment provides a method for stabilizing colorant compositions by admixing die aryketoalkene compound widi die colorant composition in an amount effective to stabiUze the composition. The arylketoalkenes desirably should be present in the colorant medium or solution at a concentration of approximately 0.1 to 50% by weight, desirably between approximately 20% and 30% by weight. If no cyclodextrin is used, die desirable range is approximately 1 part dye to approximately 20 parts arylketoalkene.

Although the arylketoalkene compound need only be associated with the colorant, in some embodiments of die present invention, die arylketoalkene compound may be covalendy bonded to die colorant

Although not wanting to be limited by die following, it is dieorized that the arylketoalkene compound of die present invention stabiUzes colorants through functioning as a singlet oxygen scavenger. In the alternative, it is theorized tiiat the arylketoalkene compound functions as a stabdizer of a colorant via the resonance of the unshared electron pairs in the p orbitals, e.g., it functions as an energy sink.

As a practical matter, the colorant ultraviolet radiation transorber, modified photoreactor, arylketoalkene stabilizer, and molecular includant are likely to be soUds depending upon die constituents used to prepare the molecules. However, any or all of such materials can be a Uquid. The colored composition can be a Uquid either because one or more of its components is a

Uquid, or, when the molecular includant is organic in nature, a solvent is employed. Suitable solvents include, but are not limited to, amides, such as N,N-dimethylformamide; sulfoxides, such as dimethylsulfoxide; ketones, such as acetone, methyl ethyl ketone, and methyl butyl ketone; ahphatic and aromatic hydrocarbons, such as hexane, octane, benzene, toluene, and die xylenes; esters, such as ethyl acetate; water; and die like. When the molecular includant is a cyclodextrin, particularly suitable solvents are the amides and sulfoxides.

In an embodiment where die composition of the present invention is a soUd, the effectiveness of the above compounds on the colorant is improved when die colorant and die selected compounds are in intimate contact To this end, the thorough blending of die components, along widi otiier components which may be present is desirable. Such blending generaUy is accomplished by any of the means known to those having ordinary skiU in the art. When the colored composition includes a polymer, blending is faciUtated if the colorant and die ultraviolet radiation transorber are at least partly soluble in softened or molten polymer. In such case, the composition is reactily prepared in, for example, a two-roll miU. Alternatively, the composition of die present invention can be a Uquid because one or more of its components is a Uquid.

For some applications, the composition of die present invention typically wiU be utilized in paniculate form. In other apptications, the particles of the composition should be very small. Methods of forming such particles are weU known to those having ordinary skiU in the art

The colored composition of the present invention can be utilized on or in any substrate. If one desires to mutate the colored composition that is present in a substrate, however, the substrate should be substantiaUy transparent to the ultraviolet radiation which is employed to mutate the colorant That is, the ultraviolet radiation wiU not significandy interact with or be absorbed by die substrate. As a practical matter, the composition typicaUy will be placed on a substrate, with die most common substrate being paper. Other substrates, including, but not limited to, woven and nonwoven webs or fabrics, films, and the like, can be used, however.

The colored composition optionally may also contain a carrier, the nature of which is weU known to those having ordinary skill in the art. For many apptications, the carrier wiU be a polymer, typicaUy a thermosetting or thermoplastic polymer, with the latter being the more common.

Further examples of thermoplastic polymers include, but are not limited to: end-capped polyacetals, such as poly(oxymethylene) or polyformaldehyde, poly(trichloroacetaldehyde), poly(n-valeraldehyde), poly(acetaldehyde), poly(propionaldehyde), and die like; acrylic polymers, such as polyacrylamide, poly(acryUc acid), poly(methacryUc acid), poly(etiιyl acrylate), poly(methyl methacrylate), and die like; fluorocarbon polymers, such as poly(tetrafluoroethylene), perfluorinated ethylenepropylene copolymers, ethylenetetrafluoroethylene copolymers, poly-(chlorotrifluoroethylene) ₎ ethylene-chlorotrifluoroediylene copolymers, poly(vinyhdene fluoride), poly(vinyl fluoride), and die like; epoxy resins, such as the condensation products of epichlorohydrin and bisphenol A; polyamides, such as poly(6- aminocaproic acid) or poly(e-caprolactam), poly(hexamethylene adipamide), poly(hexamedιylene sebacamide), poly(ll-aminoundecanoic acid), and die like; polyaramides, such as poly(imino-l,3-phenyleneiminoisophthaloyl) or poly( - phenylene isophthalamide), and die like; parylenes, such as poly-p-xylylene, poly(chloro-p-xylene), and die like; polyaryl ethers, such as poly(oxy-2,6- dimethyl-l,4-phenylene) or poly(p-phenylene oxide), and die Uke; polyaryl sulfones, such as poly (oxy-l,4-phenylenesulfonyl-l,4-phenyleneoxy- 1,4- phenylene-isopropyUdene- 1 ,4-phenylene), poly (sulf onyl- 1 ,4-phenyleneoxy- l,4-phenylenesulfonyl-4,4-biphenylene), and die like; polycarbonates, such as poly(bisphenol A) or poly(carbonyldioxy-l,4-phenyleneisopropyhdene-l,4- phenylene), and die like; polyesters, such as poly(ethylene terephthalate), poly(tetramethylene terephthalate), poly(cyclohexylene-l,4-dimethylene terephthalate) or poly(oxymetiιylene-l,4- cyclohexylenemethyleneoxyterephthaloyl), and the like; polyaryl sulfides, such as poly(p-phenylene sulfide) or poly(thio-l,4-phenylene), and die like; polyimides, such as poly(pyromelUtimido-l,4-phenylene), and die Uke; polyolefins, such as polyethylene, polypropylene, poly(l-butene), poly(2- butene), poly(l-pentene), poly(2-pentene), poly(3-methyl-l-pentene), poly(4- methyl- 1-pentene), l,2-poly-l,3-butadiene, l,4-poly-l,3-butadiene, polyisoprene, polychloroprene, polyacrylonitrile, poly(vinyl acetate), poly(vinyhdene chloride), polystyrene, and the like; and copolymers of die foregoing, such as acrylonitrile-butadienestyrene (ABS) copolymers, styrene-n- butylmethacrylate copolymers, ethylene-vinyl acetate copolymers, and die like. Some of the more commonly used diermoplastic polymers include styrene-n-butyl methacrylate copolymers, polystyrene, styrene-n-butyl acrylate

copolymers, styrene-butadiene copolymers, polycarbonates, poly(metiιyl methacrylate), poly(vinyUdene fluoride), polyamides (nylon- 12), polyethylene, polypropylene, ethylene-vinyl acetate copolymers, and epoxy resins.

Examples of thermosetting polymers include, but are not limited to, alkyd resins, such as phthahc anhydride-glycerol resins, maleic acid-glycerol resins, adipic acid-glycerol resins, and phthahc anhydride-pentaerythritol resins; aUyUc resins, in which such monomers as diaUyl phthalate, diaUyl isophdialate diaUyl maleate, and diaUyl chlorendate serve as nonvolatile cross-linking agents in polyester compounds; amino resins, such as aniline-formaldehyde resins, ethylene urea-formaldehyde resins, dicyandiamide-formaldehyde resins, melamine-formaldehyde resins, sulfonamide-formaldehyde resins, and urea- formaldehyde resins; epoxy resins, such as cross-linked epichlorohydrin- bisphenol A resins; phenoUc resins, such as phenol-formaldehyde resins, including Novolacs and resols; and thermosetting polyesters, silicones, and urethanes.

In addition to the colorant, and ultraviolet radiation transorber or functionaUzed molecular includant, modified photoreactor, arylketoalkene stabihzer, and optional carrier, the colored composition of die present invention also can contain additional components, depending upon die appUcation for which it is intended. Examples of such additional components include, but are not timited to, charge carriers, stabilizers against thermal oxidation, viscoelastic properties modifiers, cross-linking agents, plasticizers, charge control additives such as a quaternary ammonium salt; flow control additives such as hydrophobic silica, zinc stearate, calcium stearate, tithium stearate, polyvinylstearate, and polyethylene powders; and fillers such as calcium carbonate, clay and talc, among other additives used by those having ordinary skiU in the art. Charge carriers are well known to those having ordinary skill in the art and typicaUy are polymer-coated metal particles. The identities and amounts of such additional components in die colored composition are weU known to one of ordinary skill in the art.

The present invention is further described by die examples which follow. Such examples, however, are not to be construed as limiting in any way either die spirit or scope of the present invention. In the examples, all parts are parts by weight unless stated otherwise.

Example 1

This example describes the preparation of a b-cyclodextrin molecular includant having (1) an ultraviolet radiation transorber covalendy bonded to the cyclodextrin outside of die cavity of the cyclodextrin, and (2) a colorant associated widi the cyclodextrin by means of hydrogen bonds and/or van der

Waals forces.

A. Friedel-Crafis Acylation of Transorber

A 250-ml, three-necked, round-bottomed reaction flask was fitted widi a condenser and a pressure-equalizing addition funnel equipped with a nitrogen inlet tube. A magnetic stirring bar was placed in die flask. While being flushed widi nitrogen, the flask was charged widi 10 g (0.05 mole) of 1-hydroxycyclohexyl phenyl ketone (IRGACURE 184, Ciba-Geigy Corporation, Hawthorne, New York), 100 ml of anhydrous tetrahydofuran (Aldrich Chemical Company, Inc., MUwaukee, Wisconsin), and 5 g (0.05 mole) of succinic anhydride (Aldrich Chemical Co., Milwaukee, WI). To die continuously stirred contents of the flask then was added 6.7 g of anhydrous aluminum chloride (Aldrich Chemical Co., Milwaukee, Wisconsin). The resulting reaction mixture was maintained at about 0°C in an ice bath for about one hour, after which the mixture was aUowed to warm to ambient temperature for two hours. The reaction mixture then was poured into a mixture of 500 ml of ice water and 100 ml of diethyl ether. The ether layer was removed after the addition of a smaU amount of sodium chloride to die aqueous phase to aid phase separation. The edier layer was dried over anhydrous magnesium sulfate. The ether was removed under reduced pressure, leaving 12.7 g (87 percent) of a white crystalline powder. The material was shown to be 1-hydroxycyclohexyl 4-(2-carboxyethyl)carbonylphenyl ketone by nuclear magnetic resonance analysis.

B . Preparation ofAcylated Transorber Acid Chloride

A 250-ml round-bottomed flask fitted with a condenser was charged widi 12.0 g of 1-hydroxycyclohexyl 4-(2-carboxyethyl)carbonylphenyl ketone (0.04 mole), 5.95 g (0.05 mole) of thionyl chloride (Aldrich Chemical Co., MUwaukee, Wisconsin), and 50 ml of dietiiyl ether. The resulting reaction mixture was stirred at 30°C for 30 minutes, after which time the solvent was removed under reduced pressure. The residue, a white solid, was maintained at

0.01 Torr for 30 minutes to remove residual solvent and excess thionyl chloride, leaving 12.1 g (94 percent) of 1-hydroxycyclohexyl 4-(2- chloroformylethyl)carbonylphenyl ketone.

C . Covalent Bonding ofAcylated Transorber to Cyclodextrin

A 250-ml, three-necked, round-bottomed reaction flask containing a magnetic stirring bar and fitted widi a thermometer, condenser, and pressure- equalizing addition funnel equipped widi a nitrogen inlet tube was charged with 10 g (9.8 mmole) of β-cyclodextrin (American Maize-Products Company, Hammond, Indiana), 31.6 g (98 mmoles) of 1-hydroxycyclohexyl 4-(2- chloroformylethyl)carbonylphenyl ketone, and 100 ml of N,N- dimethylformamide whUe being continuously flushed with nitrogen. The reaction mixture was heated to 50 ^* C and 0.5 ml of triethylamine added. The reaction mixture was maintained at 50 ^* C for an hour and aUowed to cool to ambient temperature. In this preparation, no attempt was made to isolate the product a β-cyclodextrin to which an ultraviolet radiation transorber had been covalendy coupled (referred to hereinafter for convenience as β-cyclodextrin- transorber).

The foregoing procedure was repeated to isolate the product of die reaction. At die conclusion of the procedure as described, the reaction mixture was concentrated in a rotary evaporator to roughly 10 percent of die original volume. The residue was poured into ice water to which sodium chloride then was added to force the product out of solution. The resulting precipitate was isolated by filtration and washed widi diethyl ether. The soUd was dried under reduced pressure to give 24.8 g of a white powder. In a tiiird preparation, die residue remaining in the rotary evaporator was placed on top of an approximately 7.5-cm column containing about 15 g of silica gel. The residue was eluted with N,N-dimetiιylformamide, with the eluant being monitored by means of Whatman® Flexible-Backed TLC Plates (Catalog No. 05-713-161, Fisher Scientific, Pittsburgh, Pennsylvania). The eluted product was isolated by evaporating the solvent. The structure of the product was verified by nuclear magnetic resonance analysis.

D. Association of Colorant with Cyclodext ^ή n-Transorber- Preparation of Colored Composition

To a solution of 10 g (estimated to be about 3.6 mmole) of b- cyclodextrin-transorber in 150 ml of N,N-dimedιylformamide in a 250-ml round-bottomed flask was added at ambient temperature 1.2 g (3.6 mmole) of

Malachite Green oxalate (Aldrich Chemical Company, Inc., Milwaukee,

Wisconsin), referred to hereinafter as Colorant A for convenience. The reaction mixture was stirred widi a magnetic stirring bar for one hour at ambient temperature. Most of the solvent tiien was removed in a rotary evaporator and die residue was eluted from a silica gel column as already described. The b- cyclodextrin-transorber Colorant A inclusion complex moved down the column first, cleanly separating from both free Colorant A and b-cyclodextrin- transorber. The eluant containing the complex was coUected and die solvent removed in a rotary evaporator. The residue was subjected to a reduced pressure of 0.01 Torr to remove residual solvent to yield a blue- green powder.

E . Mutation of Colored Composition

The b-cyclodextrin-transorber Colorant A inclusion complex was exposed to ultraviolet radiation from two different lamps, Lamps A and B. Lamp A was a 222-nanometer excimer lamp assembly organized in banks of four cyUndrical lamps having a length of about 30 cm. The lamps were cooled by circulating water through a centrally located or inner tube of the lamp and, as a consequence, they operated at a relatively low temperature, i.e., about 50°C. The power density at the lamp's outer surface typicaUy is in the range of from about 4 to about 20 joules per square meter (J/m ² ). However, such range in reatity merely reflects the capabiUties of current excimer lamp power suppUes; in the future, higher power densities may be practical. The distance from die lamp to die sample being irradiated was 4.5 cm. Lamp B was a 500-watt Hanovia medium pressure mercury lamp (Hanovia Lamp Co., Newark, New Jersey). The distance from Lamp B to the sample being irradiated was about 15 cm.

A few drops of an N,N-dimethylformamide solution of the b- cyclodextrin-transorber Colorant A inclusion complex were placed on a TLC plate and in a small polyethylene weighing pan. Botii samples were exposed to Lamp A and were decolorized (mutated to a colorless state) in 15-20 seconds. Similar results were obtained with Lamp B in 30 seconds.

PCI7US96/00661

39

A first control sample consisting of a solution of Colorant A and b- cyclodextrin in N,N-dimethylformamide was not decolorized by Lamp A. A second control sample consisting of Colorant A and 1-hydroxycyclohexyl phenyl ketone in N,N-dimethylformamide was decolorized by Lamp A within 60 seconds. On standing, however, die color began to reappear within an hour.

To evaluate the effect of solvent on decolorization, 50 mg of die b- cyclodextrin-transorber Colorant A inclusion complex was dissolved in 1 ml of solvent The resulting solution or mixture was placed on a glass microscope sUde and exposed to Lamp A for 1 minute. The rate of decolorization, i.e., die time to render die sample colorless, was direcdy proportional to the solubility of the complex in the solvent as summarized below.

Table 1

FinaUy, 10 mg of the b-cyclodextrin-transorber Colorant A inclusion complex were placed on a glass microscope slide and crushed widi a pesde. The resulting powder was exposed to Lamp A for 10 seconds. The powder turned colorless. SimUar results were obtained with Lamp B, but at a slower rate.

Example 2

Because of the possibiUty in the preparation of the colored composition described in the foUowing examples for the acylated transorber acid chloride to at least partiaUy occupy die cavity of the cyclodextrin, to the partial or complete exclusion of colorant a modified preparative procedure was carried out. Thus, this example describes die preparation of a b-cyclodextrin molecular includant having (1) a colorant at least partiaUy included within the cavity of die cyclodextrin and associated therewith by means of hydrogen bonds and/or van der Waals forces, and (2) an ultraviolet radiation transorber covalendy bonded to die cyclodextrin substantially outside of the cavity of die cyclodextrin.

A. Association of Colorant with a Cyclodextrin

To a solution of 10.0 g (9.8 mmole) of b-cyclodextrin in 150 ml of N,N-dimethylformamide was added 3.24 g (9.6 mmoles) of Colorant A. The resulting solution was stirred at ambient temperature for one hour. The reaction solution was concentrated under reduced pressure in a rotary evaporator to a volume about one-tenth of die original volume. The residue was passed over a sitica gel column as described in Part C of Example 1. The solvent in the eluant was removed under reduced pressure in a rotary evaporator to give 12.4 g of a blue-green powder, b-cyclodextrin Colorant A inclusion complex.

B. Covalent Bonding of Acylated Transorber to Cyclodextrin Colorant Inclusion Complex - Preparation of Colored Composition

A 250-ml, three-necked, round-bottomed reaction flask containing a magnetic stirring bar and fitted with a thermometer, condenser, and pressure- equalizing addition funnel equipped widi a nitrogen inlet tube was charged with

10 g (9.6 mmole) of b-cyclodextrin Colorant A inclusion complex, 31.6 g (98 mmoles) of 1-hydroxycyclohexyl 4-(2-chloroformylethyl)carbonylphenyl ketone prepared as described in Part B of Example 1, and 150 ml of N,N-dimedιylformamide while being continuously flushed widi nitrogen. The reaction mixture was heated to 50°C and 0.5 ml of triethylamine added. The reaction mixture was maintained at 50"C for an hour and allowed to cool to ambient temperature. The reaction mixture then was worked up as described in Part A, above, to give 14.2 g of b-cyclodextrin-transorber Colorant A inclusion complex, a blue-green powder.

C . Mutation of Colored Composition

The procedures described in Part E of Example 1 were repeated widi the b-cyclodextrin-transorber Colorant A inclusion complex prepared in Part B, above, widi essentially die same results.

Example 3

This example describes a method of preparing an ultraviolet radiation transorber, 2-[p-(2-metiιyllactoyl)phenoxy]etiιyl 1 ,3-dioxo-2-isoindolineacetate, designated phthaloylglycine-2959. The following was admixed in a 250 ml, three-necked, round bottomed flask fitted widi a Dean & Stark adapter with condenser and two glass stoppers:

20.5g (0.1 mole) of die wavelengdi selective sensitizer, phdialoylglycine (Aldrich Chemical Co., Milwaukee, Wisconsin); 24.6 g (O.lmole) of the photoreactor, DARCUR 2959 (Ciba-Geigy, Hawthorne, New York); 100 ml of benzene (Aldrich Chemical Co., MUwaukee, Wisconsin); and 0.4 g p- toluenesulfonic acid (Aldrich Chemical Co., Milwaukee, Wisconsin). The mixture was heated at reflux for 3 hours after which time 1.8 ml of water was coUected. The solvent was removed under reduced pressure to give 43.1 g of white powder. The powder was recrystalUzed from 30% ethyl acetate in hexane (Fisher) to yield 40.2 g (93%) of a white crystalline powder having a melting point of 153-4 ^* C. The reaction is summarized as foUows:

p-toluene sulfonic acid

Benzene

The resulting product designated phthaloylglycine-2959, had die following physical parameters:

IR [NUJOL MULL] n^ 3440, 1760, 1740, 1680, 1600 cm-1

1H NMR [CDC13] 3ppm 1.64[s], 4.25[m], 4.49[m], 6.92[m], 7.25[m], 7.86[m], 7.98[m], 8.06[m] ppm

Example 4

This example describes a metiiod of dehydrating die phdialoylglycine- 2959 produced in Example 3.

The foUowing was admixed in a 250 ml round bottomed flask fitted widi a Dean & Stark adapter with condenser: 21.6 g (0.05 mole) phthaloylglycine-

2959; 100 ml of anhydrous benzene (Aldrich Chemical Co., Milwaukee,

Wisconsin); and 0.1 g p-toluenesulfonic acid (Aldrich Chemical Co.,

MUwaukee, Wisconsin). The mixture was refluxed for 3 hours. After 0.7 ml of water had been collected in the trap, the solution was then removed under vacuum to yield 20.1 g (97%) of a white soUd. However, analysis of the white solid showed that this reaction yielded only 15 to 20% of die desired deydration product The reaction is summarized as foUows:

p- toluene sulfonic acid

Benzene

The resulting reaction product had die foUowing physical parameters:

IR (NUJOL) n _^ 1617cm-l (C=C-C=O)

Example 5

This example describes die Nohr-MacDonald elimination reaction used to dehydrate the phthaloylglycine-2959 produced in Example 3.

Into a 500 ml round bottomed flask were placed a stirring magnet 20.0g (0.048 mole) of the phtiιaloylglycine-2959, and 6.6 g (0.048 mole) of anhydrous zinc chloride (Aldrich Chemical Co., MUwaukee, Wisconsin). 250 ml of anhydrous p-xylene (Aldrich Chemical Co., MUwaukee, Wisconsin) was added and die mixture refluxed under argon atmosphere for two hours. The reaction mixture was then cooled, resulting in a white precipitate which was coUected. The white powder was tiien recrystalhzed from 20% ethyl acetate in

hexane to yield 18.1 g (95%) of a white powder. The reaction is summarized as foUows:

The resulting reaction product had die foUowing physical parameters:

Melting Point: 138°C to 140°C.

Mass spectrum: m/e: 393 M +, 352, 326, 232, 160.

IR (KB) n _^ 1758, 1708, 1677, 1600 cm-1

1H NMR [DMSO] θppm 1.8(s), 2.6(s), 2.8 (d), 3.8 (d), 4.6 (m), 4.8 (m), 7.3(m), 7.4 (m), 8.3 (m), and 8.6 (d)

13C NMR [DMSO] dppm 65.9 (CH2=)

Example 6

This example describes a method of producing a b-cyclodextrin having dehydrated phtiιaloylglycine-2959 groups from Example 4 or 5 covalendy bonded tiiereto.

The foUowing was admixed in a 100 ml round-bottomed flask: 5.0 g (4 mmole) b-cyclodextrin (American Maize Product Company, Hammond,

Indiana) (designated b-CD in the following reaction); 8.3 g (20 mmole) dehydrated phdιaloylglycine-2959; 50 ml of anhydrous DMF; 20 ml of benzene;

and 0.01 g p-tolulenesulfonyl chloride (Aldrich Chemical Co., Milwaukee, Wisconsin). The mixture was chUled in a salt/ice bath and stirred for 24 hours. The reaction mixture was poured into 150 ml of weak sodium bicarbonate solution and extracted tiiree times with 50 ml ethyl ether. The aqueous layer was then filtered to yield a white soUd comprising the b-cyclodextrin widi phthaloylglycine-2959 group attached. A yield of 9.4 g was obtained. Reverse phase TLC plate using a 50:50 DMF:acetonitrile mixture showed a new product

The b-cyclodextrin molecule has several primary alcohols and secondary alcohols with which the phthaloylglycine-2959 can react The above representative reaction only shows a single phthaloylglycine-2959 molecule for illustrative purposes.

Example 7

This example describes a metiiod of associating a colorant and an ultraviolet radiation transorber widi a molecular includant. More particularly, this example describes a mediod of associating the colorant crystal violet with die molecular includant b-cyclodextrin covalendy bonded to die ultraviolet radiation transorber dehydrated phdιaloylglycine-2959 of Example 6.

The foUowing was placed in a 100 ml beaker: 4.0 g b-cyclodextrin having a dehydrated phthaloylglycine-2959 group; and 50 ml of water. The water was heated to 70 ^* C at which point the solution became clear. Next, 0.9 g (2.4 mmole) crystal violet (Aldrich Chemical Company, Milwaukee, Wisconsin) was added to the solution, and die solution was stirred for 20 minutes. Next, the solution was then filtered. The filtrand was washed widi die filtrate and then dried in a vacuum oven at 84 ^* C. A violet-blue powder was obtained having 4.1 g (92%) yield. The resulting reaction product had the following physical parameters: U.V. Spectrum DMF n^ 610 nm (cf cv n^. 604 nm)

Example 8

This example describes a method of producing die ultraviolet radiation transorber 4(4-hydroxyphenyl) butan-2-one-2959 (chloro substituted). The following was admixed in a 250 ml round-bottomed flask fitted widi a condenser and magnetic stir bar: 17.6 g (O.lmole) of the wavelength selective sensitizer, 4(4-hydroxyphenyl) butan-2-one (Aldrich Chemical Company, MUwaukee, Wisconsin); 26.4 g (0.1 mole) of the photoreactor, chloro substituted DARCUR 2959 (Ciba-Geigy Corporation, Hawthorne, New York); 1.0 ml of pyridine (Aldrich Chemical Company, Milwaukee,

Wisconsin); and 100 ml of anhydrous tetrahydrofuran (Aldrich Chemical Company, Milwaukee, Wisconsin). The mixture was refluxed for 3 hours and the solvent partiaUy removed under reduced pressure (60% taken off)- The reaction mixture was then poured into ice water and extracted widi two 50 ml aliquots of diethyl edier. After drying over anhydrous magnesium sulfate and removal of solvent 39.1 g of white solvent remained. RecrystaUization of the powder from 30% etiiyl acetate in hexane gave 36.7 g (91%) of a white crystalline powder, having a melting point of 142-3 ^* C. The reaction is summarized in the foUowing reaction:

CH ₃ — -CH ₂ CH ₂ — P T— O— (CH ₂ ) ₂ — O— T V-C- -OH

The resulting reaction product had die foUowing physical parameters:

IR [NUJOL MULL ] __,_,_ 3460, 1760, 1700, 1620, 1600 cm-1

1H [CDC13] 3ppm 1.62[s], 4.2[m], 4.5[m], 6.9[m] ppm

The ultraviolet radiation transorber produced in this example, 4(4- hydroxyphenyl) butan-2-one-2959 (chloro substituted), may be associated wid b-cyclodextrin and a colorant such as crystal violet using the methods described above wherein 4(4-hydroxyphenyl) butan-2-one-2959 (chloro substituted) would be substituted for die dehydrated phtiιaloylglycine-2959.

Example 9

Stabilizing activity of the radiation transorber

This example demonstrates die abitity of the present invention to stabUize colorants against Ught Victoria Pure Blue BO is admixed in acetonitrile with phthaloylglycine-2959, represented by die foUowing formula:

and dehydrated phthaloylglycine-2959, represented by the foUowing formula::

Solutions were prepared according to Table 2. The dye solutions were carefuUy, uniformly spread on steel plates to a thickness of approximately 0.1 mm. The plates were then immediately exposed to a medium pressure 1200 watt high intensity quartz arc mercury discharge lamp (Conrad-Hanovia, Inc., Newark, New Jersey) at a distance of 30 cm from die Ught. The mercury discharge Ught is a source of high intensity, broad spectrum Ught that is used in accelerated fading analyses. Table 2 shows the results of the fade time with die various solutions. Fade time is defined as the time until the dye became colorless to the naked eye.

Table 2

Phthaloylglycine-2959 Victoria pure Fade Time Blue BO

3 J p paarrttss b byy weight 1 part by weight 2 min 10 p paarrttss b by weight 1 part by weight 1 1/2 min

20 parts by weight 1 part by weight TΠ sec

Dehydrated Victoria pure Fade Time Phthaloylglycine-2959 Blue BO

3 3 ppaarts by weight 1 part by weight 4 min

10 parts by weight 1 part by weight 8 min 20 parts by weight 1 part by weight >10 min

As can be seen in Table 2, when phthaloylglycine-2959 was admixed widi Victoria Pure Blue BO, the dye faded when exposed to die mercury dwascharge Ught However, when dehydrated phtiιaloylglycine-2959 was admixed widi die Victoria Pure Blue BO at a ratio of 10 parts dehydrated phthaloylglycine-2959 to one part Victoria Pure Blue BO, tiiere was increased stabilization of the dye to Ught. When die ratio was 20 parts dehydrated phthaloylglycine-2959 to one part Victoria Pure Blue BO, the dye was

substantiaUy stabilized to the mercury dwascharge Ught in the time Umits of die exposure.

Example 10

To determine whetiier die hydroxy and die dehydroxy 2959 have die capabiUty to stabUize colorants the foUowing experiment was conducted. The foUowing two compounds were tested as described below:

2959

Dehydroxy 2959 20 parts by weight of the hydroxy and die dehydroxy 2959 were admixed separately to one part by weight of Victoria Pure Blue BO in acetonitrile. The dye solutions were cwerefuUy uniformly spread on steel plates to a thickness of approximately 0.1 mm. The plates were then immediately exposed to a mercury discharge Ught at a distance of 30 cm from the light. The mercury discharge light is a source of high intensity, broad spectrum Ught that is used in accelerated fading analyses. Table 3 shows the results of the fade time with die various solutions. Fade time is defined as the time until the dye became colorless to the naked eye.

Table 3

Example 11

Stabilizing activity of the radiation transorber and a molecular includant

This example demonstrates the capabiUty of dehydrated phthaloylglycine-2959 bound to b-cyclodextrin to stabilize dyes against light. The Victoria Pure Blue BO associated widi die radiation transorber, as discussed in the examples above, was tested to determine its capabiUty to stabilize die associated dye against Ught emitted from a mercury discharge light. In addition, the Victoria Pure Blue BO alone and Victoria Pure Blue BO admixed widi b-cyclodextrin were tested as controls. The compositions tested were as foUows:

1. Victoria Pure Blue BO only at a concentration of lOmg/ml in acetonitrile.

2. Victoria Pure Blue BO included in b-cyclodextrin at a concentration of 20 mg/ml in acetonitrile.

3. The Victoria Pure Blue BO included in b- cyclodextrin to which the radiation transorber (dehydrated phthaloylglycine-2959) is covalendy attached at a concentration of 20 mg/ml in acetonitrile.

The protocol for testing the stabilizing quatities of the tiiree compositions is as foUows: the dye solutions were carefully, uniformly spread on steel plates to a thickness of approximately 0.1 mm. The plates were then immediately exposed to a medium pressure 1200 watt high intensity quartz arc mercury discharge lamp (Conrad-Hanovia, Inc., Newark, New Jersey) at a distance of 30 cm from die lamp.

Table 4

a There is a phase change after 10 minutes due to extreme heat

As shown in Table 4, only composition number 3, the Victoria Pure

Blue BO included in cyclodextrin widi die radiation transorber covalendy attached to the b- cyclodextrin was capable of stabiUzing the dye under die mercury discharge Ught

Example 12

Preparation ofepoxide intermediate of dehydrated phthaloylglycine-2959

The epoxide intermediate of dehydrated phdialoylglycine 2959 was prepared according to the foUowing reaction:

In a 250 ml, three-necked, round bottomed flask fitted widi an addition funnel, thermometer and magnetic stirrer was placed 30.0g (0.076 mol) of the dehydrated phthaloylglycine-2959, 70 ml methanol and 20.1 ml hydrogen peroxide (30% solution). The reaction mixture was stirred and cooled in a water/ice bath to maintain a temperature in the range 15°-20° C. 5.8 ml of a 6 N

NaOH solution was placed in the addition funnel and the solution was slowly added to maintain the reaction mixture temperature of 15°-20° C. This step took about 4 minutes. The mixture was then stirred for 3 hours at about 20 ^o -25° C. The reaction mixture was then poured into 90 ml of water and extracted widi two 70 ml portions of ethyl edier. The organic layers were combined and washed widi 100 ml of water, dried with anhydrous MgSO ₄ filtered, and die ether removed on a rotary evaporator to yield a white solid (yield 20.3g, 65%).

The IR showed die stretching of the C-O-C group and the material was used widiout further purification.

Example 13

Attachment of epoxide intermediate to hiol cyclodextrin

The attachment of the epoxide intermediate of dehydrated phdialoylglycine 2959 was done according to the foUowing reaction:

In a 250 ml 3-necked round bottomed flask fitted widi a stopper and two glass stoppers, aU being wired widi copper wire and attached to die flask widi rubber bands, was placed 30.0 g (0.016 mol) thiol cyclodextrin and 100 ml of anhydrous dimethylformamide (DMF) (Aldrich Chemical Co., MUwaukee,

Wisconsin). The reaction mixture was cooled in a ice bath and 0.5 ml dusopropyl etivyl amine was added. Hydrogen sulfide was bubbled into the flask and a positive pressure maintained for 3 hours. During die last hour, the reaction mixture was aUowed to warm to room temperature.

The reaction mixture was flushed widi argon for 15 minutes and then poured into 70 ml of water to which was then added 100 ml acetone. A white precipitate occurred and was filtered to yield 20.2 g (84.1%) of a white powder which was used without further purification.

In a 250 ml round bottomed flask fitted widi a magnetic stirrer and placed in an ice batii was placed 12.7 (0.031 mol), 80 ml of anhydrous DMF

(Aldrich Chemical Co., MUwaukee, Wisconsin) and 15.0 g (0.010 mol) thiol

CD. After the reaction mixture was cooled, 0.5 ml of dusopropyl ethyl amine was added and die reaction mixture stirred for 1 hour at 0°C to 5"C followed by

2 hours at room temperature. The reaction mixture was then poured into 200 ml of ice water and a white precipitate formed immediately. This was filtered and washed widi acetone. The damp white powder was dried in a convection oven at 80 ^* C for 3 hours to yield a white powder. The yield was 24.5 g (88%).

Example 14 Insertion of Victoria Pure Blue in the cyclodextrin cavity

In a 250 ml Erlenmeyer flask was placed a magnetic stirrer, 40.0 g (0.014 mol) of the compound produced in Example 13 and 100 ml water. The flask was heated on a hot plate to 80 ^* C. When the white cloudy mixture became clear, 7.43 g (0.016 mol) of Victoria Pure Blue BO powder was tiien added to die hot solution and stirred for 10 minutes then aUowed to cool to 50 ^* C. The contents were then filtered and washed with 20 ml of cold water.

The precipitate was then dried in a convention oven at 80"C for 2 hours to yield a blue powder 27.9 g (58.1%).

Example 15

The preparation of a tosylated cyclodextrin widi die dehydroxy phdialoylglycine 2959 attached thereto is performed by the following reactions:

To a 500 ml 3-necked round bottomed flask fitted widi a bubble tube, condenser and addition funnel, was placed 10 g (0.025 mole) of die dehydrated phdialoylglycine 2959 in 150 ml of anhydrous N,N-diethylformamide (Aldrich

Chemical Co., MUwaukee, Wisconsin) cooled to O'C in an ice bath and stirred with a magnetic stirrer. The synthesis was repeated except that the flask was allowed to warm up to 60°C using a warm water bath and die H ₂ S pumped into die reaction flask till the stoppers started to move (trying to release the pressure). The flask was then stirred under these conditions for 4 hours. The saturated solution was kept at a positive pressure of H ₂ S. The stoppers were held down by wiring and rubber bands. The reaction mixture was then aUowed to warm-up overnight The solution was then flushed with argon for 30 minutes and die reaction mixture poured onto 50 g of crushed ice and extracted three times (3 x 80 ml) with diethyl ether (Aldrich Chemical Co., MUwaukee, Wisconsin).

The organic layers were condensed and washed widi water and dried widi MgSO ₄ . Removal of the solvent on a rotary evaporator gave 5.2 g of a crude product. The product was purified on a siUca column using 20% ethyl acetate in hexane as eluant 4.5 g of a white soUd was obtained.

A tosylated cyclodextrin was prepared according to die following reaction:

Pyridine 0°C

To a 100 ml rou bottomed flask was placed 6.0 g β-cyclodextrin (American Maize Product Company), lO.Og (0.05 mole) /?-toluenesulfonyl chloride (Aldrich Chemical Co., MUwaukee, Wisconsin), 50 ml of pH 10 buffer solution (Fisher). The resultant mixture was stirred at room temperature for 8 hours after which it was poured on ice (approximately 100 g) and extracted with diethyl ether. The aqueous layer was then poured into 50 ml of acetone (Fisher) and die resultant, cloudy mixture filtered. The resultant white powder was then run through a sephadex column (Aldrich Chemical Co.,

MUwaukee, Wisconsin) using n-butanol, ethanol, and water (5:4:3 by volume) as eluant to yield a white powder. The yield was 10.9%.

The degree of substitution of the white powder (tosyl-cyclodextrin) was determined by ¹³ C NMR spectroscopy (DMF-d6) by comparing the ratio of hydroxysubstituted carbons versus tosylated carbons, both at die 6 position. When die 6-position carbon bears a hydroxy group, the NMR peaks for each of the six carbon atoms are given in Table 5.

Table 5

The presence of the tosyl group shifts the NMR peaks of the 5-position and 6-position carbon atoms to 68.8 and 69.5 ppm, respectively.

The degree of substitution was calculated by integrating the NMR peak for the 6-position tosylated carbon, integrating the NMR peak for the 6-position hydroxy-substituted carbon, and dividing the former by the latter. The integrations yielded 23.6 and 4.1, respectively, and a degree of substitution of 5.9. Thus, die average degree of substitution in this example is about 6.

The tosylated cyclodextrin widi die dehydroxy phdialoylglycine 2959 attached was prepared according to the foUowing reaction:

To a 250 ml round bottomed flask was added 10.0 g (4-8 mole) of tosylated substituted cyclodextrin, 20.7g (48 mmol) of thiol (mercapto dehydrated phdialoylglycine 2959) in 100 ml of DMF. The reaction mixture was cooled to 0 ^* C in an ice bath and stirred using a magnetic stirrer. To the solution was slowly dropped in 10 ml of ethyl dUsopropylamine (Aldrich Chemical Co., MUwaukee, Wisconsin) in 20 ml of DMF. The reaction was kept at 0" C for 8 hours with stirring. The reaction mixture was extracted widi diediyl edier. The aqueous layer was then treated widi 500 ml of acetone and die precipitate filtered and washed with acetone. The product was then run on a sephadex column using n-butanol, ethanol, and water (5:4:3 by volume) to yield a white powder. The yield was 16.7 g.

The degree of substitution of the functionalized molecular includant was determined as described above. In this case, the presence of the derivatized ultraviolet radiation transorber shifts the NMR peak of the 6-position carbon atom to 63.1. The degree of substitution was calculated by integrating the NMR peak for the 6-posiύon substituted carbon, integrating the NMR peak for the 6- position hydroxy-substituted carbon, and dividing die former by the latter. The integrations yielded 67.4 and 11.7, respectively, and a degree of substitution of 5.7. Thus, the average degree of substitution in this example is about 6. The reaction above shows the degree of substitution to be "n". Although n represents the value of substitution on a single cyclodextrin, and dierefore, can be from 0 to 24, it is to be understood tiiat die average degree of substitution is about 6.

Example 16

The procedure of Example 15 was repeated, except tiiat die amounts of b-cyclodextrin and p-toluenesulfonic acid (Aldrich) were 6.0 g and 5.0 g, respectively. In this case, the degree of substitution of die cyclodextrin was found to be about 3.

Example 17

The procedure of Example 15 was repeated, except tiiat die derivatized molecular includant of Example 16 was employed in place of that from Example 15. The average degree of substitution of die functionaUzed molecular includant was found to be about 3.

Example 18

This example describes the preparation of a colored composition which includes a mutable colorant and the functionaUzed molecular includant from

Example 15.

In a 250-ml Erlenmeyer flask containing a magnetic stirring bar was placed 20.0 g (5.4 mmoles) of die functionaUzed molecular includant obtained in Example 15 and 100 g of water. The water was heated to 80°C, at which temperature a clear solution was obtained. To the solution was added slowly, widi stirring, 3.1 g (6.0 mmoles) of Victoria Pure Blue BO (Aldrich). A precipitate formed which was removed from the hot solution by filtration. The precipitate was washed with 50 ml of water and dried to give 19.1 g (84 percent) of a blue powder, a colored composition consisting of a mutable colorant, Victoria Pure Blue B0, and a molecular includant having covalendy coupled to it an average of about six ultraviolet radiation transorber molecules per molecular includant molecule.

Example 19 The procedure of Example 18 was repeated, except that die functionaUzed molecular includant from Example 17 was employed in place of tiiat from Example 15.

Example 20

This example describes mutation or decolorization rates for the compositions of Examples 7 (wherein die b-cyclodextrin has dehydrated phtiialoyl glycine-2959 from Example 4 covalendy bonded thereto), 18 and 19. In each case, approximately 10 mg of the composition was placed on a steel plate (Q-Panel Company, Cleveland, Ohio). Three drops (about 0.3 ml) of acetonitrile (Burdick & Jackson, Muskegon, Michigan) was placed on top of die composition and the two materials were quickly mixed widi a spatula and spread out on die plate as a thin film. Within 5-10 seconds of the addition of the acetonitrile, each plate was exposed to die radiation from a 222-nanometer excimer lamp assembly. The assembly consisted of a bank of four cylindrical lamps having a length of about 30 cm. The lamps were cooled by circulating water through a centraUy located or inner tube of the lamp and, as a consequence, they operated at a relatively low temperature, i.e., about 50°C. The power density at the lamp's outer surface typicaUy was in the range of from about 4 to about 20 joules per square meter (J/m ² ). However, such range in reatity merely reflects the capabiUties of current excimer lamp power suppUes; in the future, higher power densities may be practical. The distance from die lamp to die sample being irradiated was 4.5 cm. The time for each film to become colorless to the eye was measured. The results are summarized in Table 6.

Table 6

Decolorization Times for Various Compositions

Composition Decolorization Times (Seconds)

Example 18 1

Example 19 3-4

Example 7 7-8_

While the data in Table 6 demonstrate die clear superiority of the colored compositions of the present invention, such data were plotted as degree of substitution versus decolorization time. The plot is shown in Figure 3. Figure 3 not only demonstrates die significant improvement of the colored compositions of die present invention when compared widi compositions

having a degree of substitution less than three, but also indicates tiiat a degree of substitution of about 6 is about optimum. That is, the figure indicates that titde if any improvement in decolonization time would be achieved with degrees of substitution greater than about 6.

Example 21 This example describes die preparation of a complex consisting of a mutable colorant and die derivatized molecular includant of Example 15.

The procedure of Example 18 was repeated, except that the functionaUzed molecular includant of Example 15 was replaced widi 10 g (4.8 mmoles) of die derivatized molecular includant of Example 15 and the amount of Victoria Pure Blue BO was reduced to 2.5 g (4.8 mmoles). The yield of washed soUd was 10.8 g (86 percent) of a mutable colorant associated with die b-cyclodextrin having an average of six tosyl groups per molecule of molecular includant.

Example 22 This example describes the preparation of a colored composition which includes a mutable colorant and a functionalized molecular includant.

The procedure of preparing a functionalized molecular includant of Example 15 was repeated, except that die tosylated b-cyclodextrin was replaced widi 10 g (3.8 mmoles) of die complex obtained in Example 21 and die amount of the derivatized ultraviolet radiation transorber prepared in Example 15 was 11.6 g (27 mmoles). The amount of colored composition obtained was 11.2 g

(56 percent). The average degree of substitution was determined as described above, and was found to be 5.9, or about 6.

Example 23 The following two compounds were tested for their abitity to stabUize

Victoria Pure Blue BO:

Dehydroxy Compound

Hydroxy Compound

This example further demonstrates the abitity of the present invention to stabilize colorants against Ught The two compounds containing Victoria Pure Blue BO as an includant in die cyclodextrin cavity were tested for Ught fastness under a medium pressure mercury discharge lamp. 100 mg of each compound was dissolved in 20 ml of acetonitrile and was uniformly spread on steel plates to a thickness of approximately 0.1 mm. The plates were then immediately exposed to a medium pressure 1200 watt high intensity quartz arc mercury discharge lamp (Conrad-Hanovia, Inc., Newark, New Jersey) at a distance of 30 cm from the lamp. The light fastness results of these compounds are summarized in Table 7.

Table 7

Cyclodexttin Compound Fade Time

DeTvy lrox Iy CTrTpoωϊd" >10 min ^a

Hydroxy Compound <3δ ^" sec a There is a phase change after 10 minutes due to extreme heat

Example 24

This example describes the preparation of films consisting of colorant, ultraviolet radiation transorber, and tiiermoplastic polymer. The colorant and ultraviolet radiation transorber were ground separately in a mortar. The desired

amounts of the ground components were weighed and placed in an aluminum pan, along with a weighed amount of a thermoplastic polymer. The pan was placed on a hot plate set at 150 ^* C and die mixture in the pan was stirred until molten. A few drops of die molten mixture were poured onto a steel plate and spread into a thin film by means of a glass microscope sUde. Each steel plate was 3 x 5 inches (7.6 cm x 12.7 cm) and was obtained from Q-Panel Company, Cleveland, Ohio. The film on the steel plate was estimated to have a thickness of the order of 10-20 micrometers.

In every instance, the colorant was Malachite Green oxalate (Aldrich Chemical Company, Inc., MUwaukee, Wisconsin), referred to hereinafter as

Colorant A for convenience. The ultraviolet radiation transorber ("UVRT") consisted of one or more of Irgacure® 500 ("UVRT A"), Irgacure® 651 ("UVRT B"), and Irgacure® 907 ("UVRT C"), each of which was described eartier and is available from Ciba-Geigy Corporation, Hawthorne, New York. The polymer was one of the foUowing: an epichlorohydrin-bisphenol A epoxy resin ("Polymer A"), Epon® 1004F (SheU Oil Company, Houston, Texas); a poly(ethylene glycol) having a weight-average molecular weight of about 8,000 ("Polymer B"), Carbowax 8000 (Aldrich Chemical Company); and a poly(ethylene glycol) having a weight-average molecular weight of about 4,600 ("Polymer C"), Carbowax 4600 (Aldrich Chemical Company). A control film was prepared which consisted only of colorant and polymer. The compositions of the films are summarized in Table 8.

Table 8

Compositions of Films Containing Colorant and Ultraviolet Radiation Transorber ("UVRT")

While stiU on the steel plate, each film was exposed to ultraviolet radiation. In each case, the steel plate having the film sample on its surface was placed on a moving conveyor belt having a variable speed control. Three different ultraviolet radiation sources, or lamps, were used. Lamp A was a 222- nanometer excimer lamp and Lamp B was a 308-nanometer excimer lamp, as already described. Lamp C was a fusion lamp system having a "D" bulb

(Fusion Systems Corporation, RockviUe, Maryland). The excimer lamps were organized in banks of four cylindrical lamps having a length of about 30 cm, with the lamps being oriented normal to the direction of motion of die belt. The lamps were cooled by circulating water through a centraUy located or inner tube of the lamp and, as a consequence, they operated at a relatively low temperature, i.e., about 50 ^* C. The power density at die lamp's outer surface typicaUy is in

2 the range of from about 4 to about 20 joules per square meter (J/m ).

However, such range in reality merely reflects the capabUities of current excimer lamp power supplies; in the future, higher power densities may be practical. Widi Lamps A and B, die distance from the lamp to die film sample

was 4.5 cm and die belt was set to move at 20 ft min (0.1 m/sec). With Lamp C, the belt speed was 14 ft/min (0.07 m/sec) and die lamp-to-sample distance was 10 cm. The results of exposing the film samples to ultraviolet radiation are summarized in Table 9. Except for Film F, the table records die number of passes under a lamp which were required in order to render die film colorless. For Film F, the table records die number of passes tried, widi die film in each case remaining colored (no change).

Table 9

Results of Exposing Films Containing

Colorant and Ultraviolet Radiation Transorber (UVRT) to Ultraviolet Radiation

Example 25

This Example demonstrates that die 222 nanometer excimer lamps iUustrated in Figure 4 produce uniform intensity readings on a surface of a substrate 5.5 centimeters from the lamps, at the numbered locations, in an amount sufficient to mutate the colorant in the compositions of the present invention which are present on the surface of the substrate. The lamp 10 comprises a lamp housing 15 with four excimer lamp bulbs 20 positioned in paraUel, the excimer lamp bulbs 20 are approximately 30 cm in length. The lamps are cooled by circulating water through a centraUy located or inner tube (not shown) and, as a consequence, die lamps are operated at a relatively low temperature, i.e., about 50 ^* C. The power density at the lamp's outer surface typicaUy is in the range of from about 4 to about 20 joules per square

2 meter (J/m ).

Table 10 summarizes the intensity readings which were obtained by a meter located on the surface of the substrate. The readings numbered 1, 4, 7, and 10 were located approximately 7.0 centimeters from the left end of die column as shown in Figure 4. The readings numbered 3, 6, 9, and 12 were located approximately 5.5 centimeters from the right end of die column as shown in Figure 4. The readings numbered 2, 5, 8, and 11 were centraUy located approximately 17.5 centimeters from each end of die column as shown in Figure 4.

TABLE 10

Example 26

This Example demonstrates that die 222 nanometer excimer lamps iUustrated in Figure 5 produce uniform intensity readings on a surface of a substrate 5.5 centimeters from the lamps, at the numbered locations, in an amount sufficient to mutate the colorant in the compositions of the present invention which are present on the surface of the substrate. The excimer lamp 10 comprises a lamp housing 15 with four excimer lamp bulbs 20 positioned in paraUel, the excimer lamp bulbs 20 are approximately 30 cm in length. The lamps are cooled by circulating water through a centraUy located or inner tube (not shown) and, as a consequence, the lamps are operated at a relatively low temperature, i.e., about 50°C. The power density at die lamp's outer surface typicaUy is in die range of from about 4 to about 20 joules per square meter

(J/m ² ).

Table 11 summarizes the intensity readings which were obtained by a meter located on die surface of the substrate. The readings numbered 1, 4, and 7 were located approximately 7.0 centimeters from the left end of die columns as shown in Figure 5. The readings numbered 3, 6, and 9 were located approximately 5.5 centimeters from the right end of the columns as shown in

5

65

Figure 5. The readings numbered 2, 5, 8 were centraUy located approximately 17.5 centimeters from each end of the columns as shown in Figure 5.

Table 11

Example 27

This Example demonstrates die intensity produced by the 222 nanometer excimer lamps iUustrated in Figure 6, on a surface of a substrate, as a function of the distance of the surface from the lamps, the intensity being sufficient to mutate the colorant in the compositions of die present invention which are present on the surface of the substrate. The excimer lamp 10 comprises a lamp housing 15 with four excimer lamp bulbs 20 positioned in paraUel, the excimer lamp bulbs 20 are approximately 30 cm in length. The lamps are cooled by circulating water through a centraUy located or inner tube (not shown) and, as a consequence, the lamps are operated at a relatively low temperature, i.e., about

50 ^* C. The power density at die lamp's outer surface typically is in the range of

2 from about 4 to about 20 joules per square meter (J/m ).

Table 12 summarizes the intensity readings which were obtained by a meter located on the surface of the substrate at position 1 as shown in Figure 6.

Position 1 was centraUy located approximately 17 centimeters from each end of die column as shown in Figure 6.

Table 12

Example 28

This example describes a metiiod of making the foUowing wavelength- selective sensitizer:

The wavelength-selective sensitizer is synthesized as summarized below:

To a 250ml round bottom flask fitted with a magnetic stir bar, and a condensor, was added 10.8 g (0.27 mole) sodium hydroxide (Aldrich), 98 g

water and 50 g ethanol. The solution was stirred whUe being cooled to room temperature in an ice bath. To the stirred solution was added 25.8 g (0.21 mole) acetophenone (Aldrich) and then 32.2 g (0.21 mole) 4- carboxybenzaldehyde (Aldrich). The reaction mixture was stirred at room temperature for approximately 8 hours. The reaction mixture temperature was checked in order to prevent it from exceeding 30 ^* C. Next, dUute HCL was added to bring the mixture to neutral pH. The white/yeUow precipitate was filtered using a Buchner funnel to yield 40.0 g (75%) after drying on a rotary pump for four hours. The product was used below witiiout further purification. The resulting reaction product had die foUowing physical parameters:

Mass. Spec, m/e (m+) 252, 207, 179, 157, 105, 77, 51.

Example 29 This example describes a method of covalendy bonding die compound produced in Example 28 to cyclodextrin as is summarized below:

To a 250 ml round bottom flask fitted widi a magnetic stir bar, condensor, and while being flushed widi argon, was placed 5.0 g (0.019 mole) of die composition prepared in Example 29, and 50 ml of anhydrous DMF (Aldrich). To this solution was slowly dropped in 2.5 g (0.019 mole) oxalyl chloride (Aldrich) over thirty minutes with vigorous stirring whUe the reaction flask was cooled in an ice-batii. After one hour, the reaction was aUowed to warm to room temperature, and tiien was stirred for one hour. The reaction mixture was used "as is" in the following step. To the above reaction mixture 5.3 g (0.004 mole) of hydroxyetiiyl substituted alpha-cyclodextrin (American

Maize Company), dehydrated by Dean and Stark over benzene for two hours to remove any water, was added and the reaction mixture stirred at room temperature with 3 drops of triethylamine added. After four hours the reaction mixture was poured into 500 ml of acetone and die white precipitate filtered using a Buchner Funnel. The white powder was dried on a rotary pump (0.1 mm Hg) for four hours to yield 8.2 g product.

The resulting reaction product had the foUowing physical parameters: NMR (DMSO-d6) d 2.80[M, CD], 3.6-4.0 [M, CD], 7.9 [C, aromatus]

,8.2 [M, aromatus of C], 8.3 [M, aromatus of C] ppm.

Example 30

This example describes a metiiod of making die foUowing wavelength- selective sensitizer, namely 4-[4'-carboxy phenyl]-3-buten-2-one:

The wavelength-selective sensitizer is synthesized as summarized below:

HOOC— (( )>— CHO

The method of Example 28 was followed except tiiat acetone (Fisher, Optima Grade) was added first, and then the carboxybenzaldehyde was added. More particularly, 32.2 (0.21 mole) of carboxybenzaldehyde was reacted widi 12.2 g (0.21 mole) of acetone in die sodium hydroxide/edianol/water mixture described in Example 28. Dilute HCl was added to bring the reaction mixture to neutral pH, yielding 37.1 g (91%) of a pale yeUow powder which was used widiout further purification in the following examples.

The resulting reaction product, namely 4-[4'-carboxy phenyl]-3-buten- 2-one, had die following physical parameters: Mass. Spec. 190 (m ⁺ ), 175, 120.

Example 31

This example describes a metiiod of covalendy bonding die 4-[4'- carboxy phenyl]-3-buten-2-one produced in Example 30 to cyclodextrin as is summarized below:

The method of Example 29 was foUowed except that 5.0 g of die 4-[4'- carboxy phenyl]-3-buten-2-one was used. More particularly, 5.0 g (0.026 mole) of die 4-[4'-carboxy phenyl]-3-buten-2-one produced in Example 30 was reacted widi 3.3 g (0.026 mole) of oxalyl chloride in any hydrous DMF at about O'C. Next, approximately 7.1 g (0.005 mole) hydroxyethyl substituted cyclodextrin was added to the mixture (5:1 ratio) under die conditions described in Example 30 and was further processed as described tiierein, to produce 10.8 g of white powder. The NMR of the product showed botii the aromatic protons of the 4-[4'-carboxy phenyl]-3-buten-2-one produced in Example 30 and die glucose protons of die cyclodextrin.

2335

71

Example 32

This example describes a method of covalendy bonding die compound produced in Example 28 to a photoreactor, namely DARCUR 2959, as is summarized below:

Beπzene Tos l acid

To a 500 ml round bottom flask fitted widi a magnetic stir bar, and condensor, was placed 20 g (0.08 mole) of the composition prepared in Example 28, 17.8 g (0.08 mole) DARCUR 2959 (Ciba-Geigy, N.Y.), 0.5g p- toluenesulfonic acid (Aldrich), and 300 ml anhydrous benzene (Aldrich). The Dean and Stark adapter was put on die flask and the reaction mixture heated at reflux for 8 hours after which point 1.5 ml of water had been coUected (tiieo. 1.43 ml). The reaction mixture was then cooled and the solvent removed on a rotary evaporator to yield 35.4 g. The crude product was recrystaUzed from 30% etiiyl acetate in hexane to yield 34.2 g (94%) of a white powder. The resulting reaction product had die foUowing physical parameters: Mass. Spectrum: 458 (m+), 440, 399, 322, 284.

Example 33

To determine whether the 4-[4'-carboxy phenyl]-3-buten-2-one produced in Example 30 has the capabiUty to stabilize colorants, the following experiment was conducted. Test films were made up containing 90% carbowax 4600 and 10% of a 1 part Victoria Pure Blue BO (Aldrich) to 19 parts 4-[4'- carboxy phenyl]-3-buten-2-one. The mixture was melted on a hot plate, stirred, then drawn down on metal plates (at approximately 60°C), using a #3 drawdown bar. A simUar sample was made widi only 1% Victoria Pure Blue BO in 99% carbowax.

The plates were exposed to a 1200 Watt Mercury medium pressure lamp for one hour, the lamp being about 2 feet from the plates. After one hour, die

Victoria Pure Blue BO plate was essentiaUy colorless, whUe the plate having the mixture of Victoria Pure Blue BO and 4-[4' -carboxy phenyl]-3-buten-2-one thereon had not changed.

Example 34

A further experiment to determine the colorant stabilizing capabiUty of die 4-[4'-carboxy phenyl]-3-buten-2-one produced in Example 30 is as foUows. The experiment used in Example 33 was repeated except that no carbowax was used. Instead, the materials were dissolved in acetonitrile and a film formed, aUowed to dry, and tiien exposed to die 1200 Watt lamp. Again, after one hour, the dye (Victoria Pure Blue BO) was essentially colorless wlύle the mixture containing the 4-[4' -carboxy phenyl]-3-buten-2-one was unchanged in color.

Example 35 A further experiment to determine die colorant stabilizing capabiUty of the compounds produced in Examples 28, 29, 30 (4-[4' -carboxy phenyl]-3- buten-2-one), and 31 (4-[4' -carboxy phenyl]-3-buten-2-one/cyclodextrin) was as follows. The experiment used in Example 34 was repeated for aU four compounds, separately. More particularly, five metal plates were prepared using die acetonitrile slurry method of Example 34, widi die compositions as foUows:

( 1 ) Victoria Pure Blue BO only;

(2) Victoria Pure Blue BO + the compound produced in Example 28

(3) Victoria Pure Blue BO + the compound produced in Example 30

(4) Victoria Pure Blue BO + the compound produced in Example 29

(5) Victoria Pure Blue BO + the compound produced in Example 31.

In compositions (2) through (5), die compositions contained one part Victoria Pure Blue BO per 20 parts of the compounds produced in the above examples. More particularly, 0.1 g of Victoria Pure Blue BO was mixed widi approximately 2.0 g of one of the compounds produced in the above examples, in 10 ml of acetonitrile. The mixtures were drawn down using a #8 bar and aUowed to air dry in a ventilation hood. AU of the plates were simultaneously

exposed to die 1200 Watt mercury lamp for one hour. Each plate was half covered with aluminum foU during exposure to the lamp to maintain a reference point with respect to fading of the colorant After one hour under the lamp, mixture (1) had gone colorless, whUe mixtures (2) through (5) aU remained unchanged.

Example 36

Another experiment to determine the colorant stabilizing capabiUty of the compound produced in Example 29 was as foUows. Briefly described, die compound of Example 29 was used with color inks removed from the color cartridges of a CANON BJC-600e bubble jet color printer. The ink was re- instaUed into the cartridges, which were instaUed into the ink jet printer, and color test pages were generated. The fortieth color test page was used in the present study. More particularly, the four cartridges were of B JI-201 , and die four inks

(cyan, magenta, black, and yeUow) were prepared as follows:

(1) Cyan

About 3.8 ml of the colored ink in the cartridge was removed, having a viscosity of 12 seconds for 3 ml measured in a 10 ml pipette. About 0.4 g of the compound produced in Example 29 was added to the 3.8 ml and mixed for

15 minutes. The ink solution prepared was hazy, and had a viscosity of 19 seconds for 3 ml.

(2) Magenta

About 4.8 ml of the colored ink in the cartridge was removed, having a viscosity of 12 seconds for 3 ml. About 0.43 g of the compound of Example

29 was added to die 4.8 ml and mixed for fifteen minutes, producing a ink solution having a viscosity of 18 seconds for 3 ml.

(3) Black

About 7.2 ml of the ink in the cartridge was removed, having a viscosity of 8 seconds for 3 ml. About 0.72 g of the compound of Example 29 was added to die 7.2 ml and mixed for fifteen minutes, producing a hazy ink solution having a viscosity of 15 seconds for 3 ml.

(4) Yellow

About 4.0 ml of the colored ink in the cartridge was removed, having a viscosity of 4 seconds for 3 ml. About 0.41 g of the compound of Example 29

was added to die 4.0 ml and mixed for fifteen minutes, producing a hazy ink solution having a viscosity of 7 seconds for 3 ml.

The cartridges were then refiUed with die corresponding ink solutions

(1) through (4) above. Forty pages were run off, and die fortiedi page was exposed to a 1200 Watt medium pressure mercury lamp with a control sheet for nine hours. The control sheet is the fortieth color test page run off using the ink compositions that were in the original ink cartridges.

The results of this experiment were as follows. After three hours under the 1200 Watt lamp, the control was 40 to 50% bleached, whUe die inks containing the compound produced in Example 29 were unchanged. After nine hours, die control was 50 to 60% bleached while die inks containing the compound of Example 29 were only about 10 to 20 % bleached. Accordingly, die compound produced in Example 29 is capable of stabiUzing the dyes found in standard ink jet inks.

Example 37 Another experiment to determine die colorant stabilizing capabiUty of the compound produced in Example 29 is as follows. The stabihty of the ink solutions produced in Example 36 were studied as described below. The forty-eighdi sheet (test sheet) was generated using the ink solutions

(1) through (4) of Example 36 each containing about 10% of die compound of Example 29, and was tiien exposed to a 1200 Watt lamp along widi a control sheet (generated from die commerciaUy avaUable ink from the cartridges before the compound of Example 29 was added). The sheets were monitored each hour of exposure and "fade" was determined by die eye against an unexposed sheet. The results of exposing the sheets to the 1200 Watt lamp are summarized in Table 13, where NC= no change.

Table 13

Irradiation

Accordingly, the compound prepared in Example 29 works weU as a dye stabilizer to visible and ultraviolet radiation.

Having thus described die invention, numerous changes and modifications hereof wiU be readUy apparent to those having ordinary skid in the art, without departing from the spirit or scope of the invention.