The present invention relates to photochromatic compositions endowed with light fatigue resistance.

More specifically, the present invention relates to photochromatic compositions endowed with light fatigue resistance comprising at least one photoch- romatic compound belonging to the group of spiro- indolino-oxazines, spiro-isoindolino-oxazines, or spiro-pyrans and at least one compound belonging to the group of enamines consisting of derivatives of ß-ketoesters, or S-ketoamides or 1,3-diketones with primary or secondary aliphatic or aromatic amines.

The present invention also relates to polymeric compositions containing said photochromatic composi- tions and the photochromatic articles obtained from the processing of these polymeric compositions.

A further object of the present invention relates

to coating compositions, such as for example, paints, lacquers, paints or lacquers based on hybrid polysilo- xanes and/or silica gel, compositions based on plastic materials, containing said photochromatic composi- tions.

Photochromatic compounds are substances which have the characteristic of reversibly changing colour and/or degree of light transmission when exposed to solar or artificial light in the band ranging from UV to visible, or to some types of electromagnetic radiation, returning to their original state of colour and transmission when the initial light source is removed.

There are numerous substances with photochromatic characteristics, which belong to various groups of both organic and inorganic compounds such as, for example, those described in the texts"Photochromism", by G. H.

Brown (Ed.), Vol. III of the Weissberger series"Tech- niques of Organic Chemistry", Wiley Interscience, New York (1971) and in"Photochromism: Molecules and Sys- tem", by H. Durer and H. Bouas-Laurent (Ed.), Vol. 40 of the series"Studies in Organic Chemistry"Elsevier (1990).

Among organic photochromatic compounds, those belonging to the groups of spiro-indolino-oxazines,

spiro-pyrans and chromenes, are particularly known and used.

The above compounds are capable of giving photo- chromatic characteristics to polymerized organic materials used, for example, in the production of photochromatic lenses for eye-glasses, special inks, toys, and in many other applications.

As an example, the following patents can be mentioned: USA 3.562.172, USA 3.578.602, USA 4.215.010, USA 4.342.668, USA 5.055.576, USA 5.110.922, USA 5.186.867, EP 146.135, EP 134.633, EP 141.407, EP 245.020, IT 1.223.348 and IT 1.238.694.

Photochromatic compounds have a limited existence as their capacity for changing colour and/or degree of light transmission when exposed to light radiation, as already mentioned above, is made irreversible as a result of decomposition due to light fatigue. Repeated exposure to light is therefore responsible for a loss in the photochromatic properties of these compounds which, at times, have undesired colouring. Light stabilizers are used, among others, to overcome this phenomenum.

For example, U. S. patent 3.212.898 describes the use of ultraviolet light stabilizers, such as benzo- phenones and benzotriazoles, to improve the light

fatigue resistance of photochromatic substances belong- ing to the group of spiro-pyrans.

U. S. patent 4.720.356, on the other hand, dis- closes photochromatic compositions endowed with light fatigue resistance which comprise a spiro-oxazine combined with a sterically hindered amine selected from those normally used for the ultraviolet light stabili- zation of organic polymers.

European patent application EP 195.898 describes the use of sterically hindered amines associated with UV quenchers of excited states based on nickel.

The Applicant has now found that compounds belong- ing to the group of enamines consisting of derivatives of ß-ketoesters, or ß-ketoamides or 1,3-diketones with primary or secondary aliphatic or aromatic amines are capable of increasing the light fatigue resistance of photochromatic compounds belonging to the group of spiro-indolino-oxazines, spiro-isoindolino-oxazines, or spiro-pyrans.

The present invention therefore relates to photo- chromatic compositions comprising: (a) at least one photochromatic compound belonging to the group of spiro-indolino-oxazines, spiro- pyrans, or spiro-isoindolino-oxazines; (b) at least one compound belonging to the group of

enamines consisting of derivatives of ß-keto- esters, or ß-ketoamides or 1,3-diketones with primary or secondary aliphatic or aromatic amines.

Photochromatic compounds (a) belonging to the group of spiro-indolino-oxazines which can be used for the purposes of the present invention are selected from compounds having general formula (I): wherein: Ri and R2, the same or different, represent a hydrogen atom; a halogen atom selected from fluorine, chlorine and bromine; a linear or branched Cri-c alkyl or haloalkyl group; a linear or branched C1-C5 alkoxyl group; a nitro group; a cyano group; R3 and R4, the same or different, represent a linear or branched C-Cs alkyl group; a phenyl group; a benzyl group; or, R3 and R4 considered jointly with the carbon atom to which they are

bound, represent a C5-C8 cycloalkyl group; <BR> <BR> <BR> R5 represents a linear or branched Ca-C5 alkyl group; a phenyl group; a benzyl group; an allyl group; R6 represents a hydrogen atom; a linear or bran- <BR> <BR> <BR> ched Ci-c5 alkyl group; or an-NR8R9 group wherein<BR> <BR> <BR> R8 represents a linear or branched Cr-C5 alkyl gro- up, a phenyl group, a benzyl group, and R9 repre- sents a hydrogen atom, or has the same meanings as R8; or R8 and R9 considered jointly with the nitro- gen atom to which they are bound, form a C5-C12 cyclic structure, optionally containing another heteroatom selected from oxygen and nitrogen; R7 represents a hydrogen atom; a halogen atom selected from fluorine, chlorine and bromine; a linear or branched Ca-C5 alkyl or haloalkyl group; a linear or branched Cl-c5 alkoxyl group; a cyano group; a C1-C5 alkylthio group; a carboxylated ester having from 1 to 3 carbon atoms in the ester portion; a condensed heterocyclic aromatic ring with 5 or 6 atoms; X represents CH or N.

In particular, when groups Ri and R2 do not repre- sent a hydrogen atom, they can be bound to any of positions 4,5,6 and 7 of the indolinic part of the

molecule. In addition, when group R7 does not represent a hydrogen atom or a condensed aromatic or heterocyclic ring, it can be present in any of positions 7', 8', 9' and 10'of the naphthenic part of the molecule.

Preferred compounds having general formula (I) for the purposes of the present invention are those where- in: -Ri and R2 each independently represent a hydrogen atom; or a methyl group; -R3 and R4 both represent a methyl group; or, considered jointly, represent a cyclohexyl group; -R5 represents a methyl group; -R6 represents a hydrogen atom; or an-NR8R9 group wherein groups R8 and R9, together with the nitro- gen atom to which they are bound, represent a piperidyl, morpholyl, pyrrolidyl or hexamethylene- imine ring structure; -R7 represents a hydrogen atom; or a methoxyl group; and X represents CH.

Specific examples of photochromatic compounds having general formula (I) which can be used for the purposes of the present invention but which in no way limit the scope of the invention itself, are: 1,3,3,4,5 or 1,3,3,5,6-pentamethyl spiro- [indol- ino-2,3'- [3H]-naphtho- (2, 1-b)- (1, 4)-oxazine], having the formula:

known under the trade-name of Variacrol Blue Dus ouf Great Lakes; 1,3,3-trimethyl spiro- [indolino-2, 3'- [3H]-naphtho- (2,1-b)- (1, 4)-oxazine]; 1,3,3-trimethyl spiro- [indolino-6'- (1-piperidyl)- 2,3'- [3H]-naphtho- (2, 1-b)- (1, 4)-oxazine], having the formula:

known under the trade-name of Variacrol Red PNOs of Great Lakes; 1,3,3-trimethyl spiro- [indolino-6'- (1-morpholyl)- 2,3'- [3H]-naphtho- (2, 1-b)- (1, 4)-oxazine]; 1,3,3,4,5 or 1,3,3,5,6-pentamethyl spiro- [indol- ino-6'- (l-piperidyl)-2, 3'- [3H]-naphtho- (2, 1-b)- (1,4)-oxazine]; 1,3,3-trimethyl spiro- [indolino-6'- (1-piperidyl)- 9'- (methoxy)-2, 3'- [3H]-naphtho- (2, 1-b)- (1,4)- oxazine].

The photochromatic compounds having general formula (I) are prepared as described, for example, in U. S. patent 5.180.524.

Photochromatic compounds (a) belonging to the group of spiro-pyrans which can be used for the purposes of the present invention are selected from compounds represented by the following general formu- lae: indolino-sDiro-pvrans having general formula (II):

indolino-siro-naphtho-pvrans having qeneral formula<BR> <BR> (III) : benzothiazolino-sPiro-pvrans havina general formula<BR> <BR> (IV) : benzo-oxazolino-spiro-pvranshaving-general formula In the above general formulae (II), (III), (IV) and (V), the substituents have the following meanings: - R10 and R11, each independently, represent linear or branched C1-C10 alkyl groups or C6-C14 aryl groups;

-Ra2 represents a linear or branched Cl-cl alkyl group, said alkyl group optionally substituted with one or more halogen atoms selected from fluorine, chlorine and bromine, hydroxyl groups, linear or branched C2-Clo carboalkoxyl groups, linear or branched Ci-ciao alkoxyl groups, amine groups; or an aryl group; -Rl4 represents a hydrogen atom; a linear or branched Cl-cl alkyl group; a linear or branched Cl-cl alkoxyl group; an aryl group; -R13 and R15, each independently, represent a hydro- gen atom; mono-or polysubstitution groups select- ed from C1-C10 alkyl groups optionally substituted; halogen atoms selected from fluorine, chlorine and bromine; nitro groups; C1-Clo alkoxyl groups.

The compounds having general formula (II), (III), (IV) and (V), are prepared as described, for example, in the text"Photochromism", by G. H. Brown (Ed.), Vol. III of the Weissberger series"Techniques of Organic Chemistry", Wiley Interscience, New York (1971).

Photochromatic compounds (a) belonging to the group of spiro-isoindolino-oxazines which can be used for the purposes of the present invention are selected from those having general formula (VI):

wherein: a) R'represents a linear or branched C1-Clo alkyl group, said alkyl group optionally substituted with 1-10 halogen atoms selected from fluorine, chlorine and bromine, or with hydroxyl groups, linear or branched Cl-C6 alkoxyl groups, carboxyl groups, cyano groups, or with a 2,2,6,6-tetrame- thylpiperidine group; a linear or branched C2-C6 alkenyl group; an aryl group selected from phenyl, biphenyl and naphthyl, said aryl group optionally substituted with linear or branched Ci-C6 alkoxyl groups, carboxyl groups, amine groups, N, N-dialkyl (C1-C6) amine groups; a benzyl group; b) Rf and R, 21 the same or different, represent a linear or branched C1-C10 alkyl group, said alkyl group optionally substituted with 1-10 na_cgen atoms selected from fluorine, chlorine and bro- mine, or with hydroxyl groups, linear or branched

Cl-C6 alkoxyl groups, carboxyl groups, cyano groups; a linear or branched C2-C10 alkenyl group; a benzyl group; a linear or branched Ci-c 6 alkoxyl group; an N-alkyl (Ci-C6) amine group; an N, N-di- alkyl (Ci-c 6) amine group; or R'1 and R'2, consid- ered jointly with the carbon atom to which they are bound, represent a C4-Clo cycloalkyl group, said cycloalkyl group optionally substituted with halogen atoms selected from fluorine, chlorine and bromine, or with hydroxyl groups, linear or branched Ci-c 6 alkoxyl groups, carboxyl groups, cyano groups, amine groups, N-alkyl (Ci-c 6) amine groups, N, N-dialkyl (Ci-c 6) amine groups; an N, N- dialkyl (Cl-C6) amide group; a cyano group; an aryl group selected from phenyl and biphenyl; c) R'3, R'4, R'S and R'6, the same or different, repre- sent a hydrogen atom; a halogen atom selected from fluorine, chlorine, bromine and iodine; a linear or branched C1-C6 alkyl group, said alkyl group optionally substituted with 1-6 halogen atoms selected from fluorine, chlorine and bromine, or with hydroxyl groups, linear or branched Cl-C6 alkoxyl groups, cyano groups; a benzyl group; a hydroxyl group; a linear or branched Ci-c 6 alkoxyl group; an amine group; an N-alkyl (Cl-C6) amine

group; an N, N-dialkyl (Ci-c 6) amine group; a piperidine, piperazine or morpholine group; a C1-C6 carboxyalkyl group; a C2-C6 carboxyalkenyl group; a carboxyamide group; an N-alkyl (Ci-c 6) carboxya- mide group; an N, N-dialkyl (Ci-c 6) carboxyamide group; a cyano group; a nitro group; a sulfonic group; an aryl group selected from phenyl, biphe- nyl and naphthyl, said aryl group optionally substituted with N, N-dialkyl (Ci-c 6) amine groups, linear or branched Ci-c 6 alkoxyl groups, hydroxyl groups, linear or branched C1-C6 alkyl groups; an acyl group of the alkyl ketone, aryl ketone or benzyl ketone type; a linear or branched C2-C6 alkenyl group, said alkenyl group optionally substituted with one or two N, N-dialkyl (C1-C6) 4- aniline groups; an N-2,3-dihydroindoline group; a linear or branched Ci-c 6 thioether group; <BR> <BR> <BR> d) two consecutive substituents between R'3 and R'61 can represent condensation points with other aromatic, heterocyclic or quinonic rings; e) R/7 represents a hydrogen atom; a halogen atom selected from fluorine, chlorine and bromine; a linear or branched Cl-C6 alkyl group; a linear or branched Ci-C6 alkoxyl group; a phenyl group; a phenoxyl group;

f) P represents a monocyclic or polycyclic aromatic nucleus, belonging to one of the following types: benzenic represented by general formula (VII); naphthalenic represented by general formula (VIII); quinolinic represented by general formula (IX); isoquinolinic represented by general formula (X); cumarinic represented by general formula (XI); quinazolinic represented by general formula (XII); phenanthrenic represented by general formula (XIII); anthracenic represented by general formula (XIV):

wherein: -at least two adjacent substituents between R'8 and R 13 R 14 and R 21 R 22 and R'28, R'30 and R'35, R'36 and R 41 R 44 and R', R\g and R'57, R'58 and R'671 represent the condensation points with the oxazine ring, the other substituents having the same meaning described under point c).

The photochromatic compounds having general formula (VI) can be prepared by the condensation of isoindolinic compounds having general formula (VI'): wherein the substituents from R'to R'7 have the same meanings described above, with nitroso compounds having general formula (VII'): or with aromatic 1,2-quinones having general formula (VIII'):

wherein P has the same meanings described above.

The condensation reaction between the isoindolinic compounds having general formula (VI') and the nitroso compounds having general formula (VII'), indicated in Scheme 1: SCHEME 1 is carried out in the presence of an inert organic solvent such as, for example, ethyl alcohol, isopropa- nol, toluene, or a mixture of these solvents, at a temperature ranging from 50°C to 100°C, preferably between 60°C and 75°C, for a time ranging from 1 hour to 10 hours, preferably between 2 hours and 5 hours.

The reaction product thus obtained is generally puri- fied by elution on a silica column and subsequent crystallization from a solvent such as, for example, acetone, toluene, heptane.

The condensation reaction between the isoindolinic compounds having general formula (VI') and the aromatic 1,2-quinones having general formula (VIII'), indicated in Scheme 2: SCHEME 2

is carried out in the presence of an inert organic solvent such as, for example, ethyl alcohol, isopropa- nol, toluene, or a mixture of these solvents, and in the presence of aqueous ammonia at 30%, at a tempera- ture ranging from 50°C to 100°C, preferably between 60°C and 75°C, for a time ranging from 1 hour to 10 hours, preferably between 2 hours and 3 hours. The reaction product thus obtained is generally purifie by elution on a silica column and subsequent crystalliza- tion from a solvent such as, for example, acetone, toluene, heptane.

The isoindolinic compounds having general formula (VI') can be prepared according to processes known in the art described, for example, in:"Tetrahedron" (1966), Vol. 22, page 2481;"Journal of Organic Chemis- try" (1979), Vol. 44, page 1519;"Angewandte Chemie International (1968), Vol. 7, page 373.

The isoindolinic compounds having general formula (VI') are usually kept in the form of salts such as,

for example, iodides, bromides, chlorides, as the free base easily oxidizes in air.

The nitroso compounds having general formula (VII') can be prepared by the reaction of phenol compounds with nitrous acid or butyl nitrite, as described, for example, in Italian patent 1.176.858.

The aromatic 1,2-quinones having general formula (VIII') can be prepared as described, for example, in: "Journal of American Chemical Society" (1952), Vol. 74, page 278; Chemical Abstract Nr. 103-104923q; in Europe- an patent EP 245.020 and in U. S. patent 5.446.150.

Specific examples of photochromatic compounds having general formula (VI) which can be used for the purposes of the present invention, but which in no way limit its scope, are:

Compound (b) belonging to the group of enamines consisting of derivatives of ß-keto-esters, or ß-keto- amides or 1,3-diketones with primary or secondary, aliphatic or aromatic amines which can be used for the purposes of the present invention are selected from compounds having general formula (XV): wherein: -m represents an integer from 1 to 3, extremes included; -n represents an integer from 1 to 4, extremes included; -RI'l represents a triazine having one of the following general formulae (XVI), (XVII) or (XVIII):

wherein Rt'5 represents a hydrogen atom; a linear<BR> <BR> or branched Ci-ci, alkyl group; an-NHR''6 amine<BR> <BR> group or an-SR'b group wherein R"6 represents a hydrogen atom or a linear or branched Ci-c alkyl group; <BR> <BR> R''1 and R'/2'the same or different, represent a hydrogen atom; a linear or branched C1-C18 alkyl group; a linear or branched C2-C8 alkoxyalkyl group; a C5-C8 cycloalkyl group optionally contain- ing a heteroatom selected from oxygen, nitrogen and sulfur; a C6-C18 aryl group; a C7-C20 arylalkyl or alkylaryl group; a group having general formula (XIX):

wherein R''7 represents a hydrogen atom; a linear or branched Cl-cl8 alkyl group, said alkyl group optionally substituted with an-NHR''8 group or an -OR''8 group wherein R''8 represents a hydrogen atom, a linear or branched C1-C18 alkyl group, or a C6-C18 aryl group; an-OR''9 group wherein R''9 represents a hydrogen atom, or a linear or branched C1-C18 alkyl group; <BR> <BR> <BR> <BR> <BR> or, R''1 and R''2 considered jointly with the nitrogen atom, represent a C heterocyclic group optionally containing a second heteratom selected from oxygen, nitrogen and sulfur; <BR> <BR> <BR> <BR> <BR> R''3 and R'14, the same or different, represent a linear or branched Cri-c alkyl group; a C6-C18 aryl group; a C7-C20 alkylaryl or arylalkyl group; a linear or branched C1-C18 alkoxyl group; a linear or branched C2-C18 alkyleneoxyl group; a C 6-c 18 aryloxyl group; or, R''4 represents a group having general formula (XX):

wherein RI'7 has the same meanings defined above; or, R''4 represents an NR'R''. group wherein R''ao and R"11, the same or different, represent a hydrogen atom; a linear or branched Cl-cl8 alkyl group; a linear or branched C2-C8 alkoxyalkyl group; a Cs-C8 cycloalkyl group optionally contain- ing a heteroatom selected from oxygen, nitrogen and sulfur; a C6-C18 aryl group; a C7-C20 arylalkyl or alkylaryl group; a triazine having one of the following general formulae (XVI), (XVII) or (XVIII): wherein R''s has the same meanings defined above; a group having general formula (XIX):

wherein R''7 has the same meanings defined above; or, R''o and RI'll considered jointly with the nitrogen atom, represent a C5-C8 heterocyclic group optionally containing a second heteroatom selected from oxygen, nitrogen and sulfur; <BR> <BR> or R'14 represents a group having one of the following general formulae (XXI), (XXII) or (XXIII): wherein: - R''12 represents a hydrogen atom; or a linear or branched C1-C18 alkyl group; <BR> <BR> -R'r3 represents a linear or branched C1-C18 alkyl group; a-COCH2COCH3 group; or a direct

bond.

Examples of R''1. R''2 R''ro and R''"groups, in addition to a hydrogen atom, are: methyl, ethyl, propyl, isopropyl, butyl, octyl, cyclohexyl, benzyl, phenyl, ethylphenyl, methoxyethyl, 4- (2,2,6,6-tetra- <BR> <BR> <BR> <BR> <BR> <BR> methyl) piperidinyl, 4- (2,2,6,6-tetramethyl)-1-butoxy- ethylpiperidinyl, 4- (2,2,6,6-tetramethyl)-1-butoxypipe- ridinyl, 4- (2,2,6,6-tetramethyl)-1-methylpiperidinyl, 3,5-dioctylaminotriazine, 3,5-dibutylaminotriazine, etc. <BR> <BR> <BR> <BR> <BR> <BR> <BR> <P> Examples of C5-C8 heterocyclic groups, when R'',<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> and R''2 or R'<o and R''"are considered jointly with the nitrogen atom, are: morpholine, pyrrolidine, piperidine, piperazine, thiomorpholine, thiazolidine, benzothiazolidine, etc.

Examples of R''3 and R''4 groups are: methyl, ethyl, propyl, isopropyl, phenyl, oxymethyl, oxyethyl, oxybutyl, oxyoctyl, oxyoctadecyl, oxyallyl, phenoxyl, etc.

Examples of R''4 groups, when R''4 represents a group having general formula (XX), are: 4- (2,2,6,6- <BR> <BR> <BR> <BR> <BR> <BR> tetramethyl) piperidinoxy, N-methyl-4- (2,2,6,6-tetra-<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> methyl) piperidinoxy, N-methoxyethyl-4- (2,2,6,6-tetra-<BR> <BR> <BR> <BR> <BR> <BR> <BR> <BR> methyl) piperidinoxy, N-methylaminoethyl-4- (2,2,6,6- tetramethyl) piperidinoxy, etc.

Examples of R'14 groups, when R"4 represents a group having general formula (XXI), (XXII) or (XXIII) and n is 2, are: etc.

Examples of R''4 groups, when R''4 represents a group having general formula (XXI), (XXII) or (XXIII) and n is 3, are: etc.

Examples of R''4 groups, when R''4 represents a

group having general formula (XXI), (XXII) or (XXIII) and n is 4, are: etc.

Examples of RI groups are: methyl, ethyl, propyl, butyl, ethoxy, butoxy, 6-hydroxyethyl, ß-methoxyethyl, ß-butoxyethyl, methylaminoethyl, etc.

Examples of R"5, R"6, R"8, R"9, R"12 an R"13 groups, when said groups represent a linear or branched cl-cl8 alkyl group, are: methyl, ethyl, propyl, isopro- pyl, butyl, octyl, etc.

Specific examples of compounds (a) having general formula (XV) which can be used for the purposes of the present invention but which should in no way be consid- ered as limiting its scope are:

The compounds having general formula (XV) de- scribed above can be obtained with various processes.

. process for the synthesis of the compounds having general formula (XV) comprises the reaction of 1-4 moles of a primary or secondary, aliphatic or aromatic amine, having general formula (XXIV): HNR''1R''2 (XXIV) wherein R''1 and R''2 have the same meanings defined above, with 1-3 moles of a S-keto-ester, or a ß-keto- amide, or a 1,3-diketone having general formula (XXV): wherein R''31 R''4 and n have the same meanings defined above.

The above reaction takes place in the presence of an inert organic solvent, preferably a hydrocarbon, in particular toluene, at a temperature ranging from 60°C to 160°C, preferably from 115°C to 150°C, at atmospher- ic pressure, and for a time ranging from 0.5 to 24

hours, preferably from 3 to 10 hours. Acetic acid can optionally be added as catalyst to this reaction.

During the above reaction, reaction water is released which is separated by azeotropic distillation using an apparatus for azeotropic distillation, whereas the organic solvent is recycled.

At the end of the reaction, the solvent and possible acetic acid present are removed by distilla- tion thus obtaining a raw product. The desired compound having general formula (XV) is purified from the raw product thus obtained, by fractionated distillation, operating under vacuum, at a pressure ranging from 0.1 mm/Hg to 50 mm/Hg and a temperature ranging from 40°C to 200°C. Or, said compound having general formula (XV) is separated by crystallization using techniques known in the art.

Examples of primary or secondary, aliphatic or aromatic amines, having general formula (XXIV) which can be used for the purposes of the above process are: cyclohexylamine, n-butylamine, tert-butylamine, n-octy- lamine, tert-octylamine, n-octadecylamine, n-dodecylam- ine, benzylamine, 2-methoxyethylamine, 2-furfurylamine, pyrrolidine, piperidine, morpholine, dibenzylamine, aniline, diphenylamine, melamine, 4-amino-2,2,6,6-te- tramethylpiperidine, 4-amino-2,2,6,6-tetramethyl-1-me-

thylpiperidine, 4-amino-2,2,6,6-tetramethyl-1-butoxyet- hylpiperidine, 1-amino-3,5-dioctylaminotriazine, etc.

Examples of ß-keto-esters or ß-keto-amides, or 1,3-diketones having general formula (XXV) which can be used for the purposes of the above process are: ethyl acetoacetate, allyl acetoacetate, phenyl acetoacetate, ethyl benzoylacetate, acetylacetone, benzoylacetone, p-toluylacetone, 4- (2,2,6,6-tetramethyl) piperidinyl acetoacetate, N-methyl-4- (2,2,6,6-tetramethyl) piperid- inyl acetoacetate, acetoacetamide, acetoacet-4- (2, 2,- 6,6-tetramethylpiperidine) amide, acetoacet- (3,5-dibu- tyltriazine)-1-amide, etc.

The enaminic function of the compounds having general formula (XV) synthesized by means of the process described above, is confirmed by NMR spectrome- try analysis (obtained using a BRUKER AC 200 spectrome- ter) effected on samples with a high purity (> 95% confirmed by gas-chromatography).

Other processes which can be used for the prepara- tion of the compounds having general formula (XV) however, are described in literature such as, for example, in Houben-Weil (1957), Vol. 11/1, pages 172- 178.

Preferred photochromatic compounds (a) for the purposes of the present invention are: 1,3,3,4,5 or 1,3,3,5,6-pentamethyl spiro- [indol- ino-2,3'- [3H]-naphtho- (2, 1-b)- (1, 4)-oxazine], having the formula:

known under the trade-name of Variacrol Blue Dus ouf Great Lakes; 1,3,3-trimethyl spiro- [indolino-6'- (1-piperidyl)- having the formula: known under the trade-name of Variacrol Red PNO of Great Lakes; -compound having formula (VIA):

-compound having formula (VIB): Preferred compounds belonging to the group of enamines (b) for the purposes of the present invention are: -enamine having general formula (a1): wherein Ra represents one of the following groups: CH3-OCH2CH2-; C4H9-; C5H11-; C8H17-; C12H25-; C18H37;

enamine having general formula (a2): wherein Rb represents one of the following groups: -CH3, -C2H5, -C3H7, -C4H9; -C8H17; c12H25; -C18H37; and Rc represents a hydrogen atom, or a CH3; enamine having general formula (a3): wherein Rc represents a hydrogen atom, or a CH3;

-enamine having formula (a4): -enamine having formula (a5): For the purposes of the present invention, the ratio between the photochromatic compound (a) and the compound belonging to the group of enamines (b) is between 1: 1 and 1: 10, preferably between 1: 2 and 1: 6.

The photochromatic compounds of the present invention can be applied to the surface or incorporated in mass into the desired articles, using techniques already known in the art and described hereunder. For the purposes of the present invention, the photochrom- atic compounds (a) and the compounds belonging to the group of enamines (b) can also be applied or incorpo- rated separately into the desired articles.

Some polymeric photochromatic end-articles can be obtained with moulding techniques such as, for example, injection or compression moulding, starting from polymers in which the composition of the present invention or its components (a) and (b) separately, is homogeneously dispersed in mass.

Alternatively, said composition or said components

(a) and (b), can be dissolved in a solvent, together with the polymeric material such as, for example, polymethyl methacrylate, polyvinyl alcohol, polyvinyl butyral, cellulose acetate butyrate or epoxy, polysil- oxane, urethane resin. The mixture thus obtained is deposited on a transparent support to form, after evaporation of the solvent, a photochromatic coating.

The above composition or above compounds (a) and (b) can also be added to a polymerizable monomer such as, for example, a meth (acrylic) or allyl carbonate monomer, so that, after polymerization carried out in the presence of a suitable initiator such as, for example, azo-bis (isobutyronitrile) in the case of the meth (acrylic) monomer or a peroxyketal in the case of the allyl carbonate monomer, they are uniformly incor- porated in the resin formed.

Finally, the composition or compounds (a) and (b), can be applied to a transparent substrate such as, for example, polycarbonate, polymethyl methacrylate or polydiethylene glycol bis (allyl carbonate), by surface impregnation obtained by putting the substrate in contact, at a suitable temperature, with a solution or dispersion containing the mixture or compounds (a) and (b), operating according to a method described, for example, in U. S. patent 5.130.353.

The photochromatic compositions of the present invention or compounds (a) and (b), have the charac- teristic of being able to be incorporated in mass or using one of the techniques described above, into various organic polymers such as, for example, high density polyethylene (HDPE), low density polyethylene (LDPE), ethylene-vinylacetate copolymer, polyether amides, polypropylene, polymethylmethacrylate, polyvi- nyl alcohol, polyvinyl butyral, cellulose acetate butyrate, epoxy, polysiloxane or urethane resins, polycarbonate, polydiethylene glycol bis (allyl carbon- ate), polyamides, polyesters, etc.

A further object of the present invention there- fore relates to polymeric compositions comprising the above organic polymers and the above photochromatic compositions and the photochromatic articles obtained from their processing.

The photochromatic compositions of the present invention or compounds (a) and (b) are added to the above polymeric compositions in such a quantity that the photochromatic compound (a) is present in a quanti- ty of 0.01% to 5% by weight, preferably between 0.1% and 2% by weight, and the compound belonging to the group of enamines (b) is present in a quantity ranging from 0.1% to 10% by weight, preferably between 0.1% and

6% by weight.

The photochromatic compositions of the present invention can also be added to coating compositions, such as for example, paints, lacquers, paints or lacquers based on hybrid polysiloxanes and/or silica gel, compositions based on plastic materials.

A further object of the present invention conse- quently relates to coating compositions, such as for example, paints, lacquers, paints or lacquers based on hybrid polysiloxanes and/or silica gel, compositions based on plastic materials, containing said photochrom- atic compositions.

The photochromatic compositions of the present invention or compounds (a) and (b) are added to the above coating compositions in such a quantity that the photochromatic compound (a) is present in a quantity of 0.01% to 5% by weight, preferably between 0.1% and 2% by weight, and the compound belonging to the group of enamines (b) is present in a quantity ranging from 0.1% to 15% by weight, preferably between 0.1% and 8% by weight.

Paints or lacquers based on hybrid polysiloxanes and/or silica gel are obtained by means of the"sol- gell'process described, for example, by M. Nogami, Y.

Abe in:"Journal of Materials Science" (1995), Vol. 30,

pages 5789-5792.

The above coating compositions can be applied to the substrate (metal, plastic, wood, etc.) using the conventional methods such as, for example, brushing, spraying, pouring, dipping or electrophoresis.

The photochromatic compositions of the present invention can be combined, as already mentioned above, with other conventional additives or their mixtures.

These additives are added in a quantity ranging from about 0.1% to about 5% by weight of the weight of the polymeric compositions to be stabilized, preferably from about 0.5% to about 3% by weight. Some of the additives used are listed below as an example.

1. Antioxidants 1.1 Alkylated monophenols such as, for example: 2,6-di-t-butyl-4-methylphenol; 2-t-butyl-4,6-dimethylphenol; 2,6-di-t-butyl-4-ethylphenol; 2,6-di-t-butyl-4-n-butylphenol; 2,6-di-t-butyl-4-isobutylphenol; 2,6-di-cyclopentyl-4-methylphenol; 2-(a-methylcyclohexyl)-4,(a-methylcyclohexyl)-4, 6-dimethylphenol; 2,6-dioctadecyl-4-methylphenol; 2,4,6-tricyclohexylphenol; 2,6-di-t-butyl-4-methoxymethylphenol;

2,6-di-nonyl-4-methylphenol; 2,4-dimethyl-6- (1'-methylundec-1'-yl) phenol; 2,4-dimethyl-6- (1'-methylhectadec-1'-yl) phenol; 2,4-dimethyl-6- (1'-methyltridec-1'-yl) phenol; and their mixtures.

1.2 Alkylthiomethylphenols such as, for example: 2,4-dioctylthiomethyl-6-t-butylphenol; 2,4-dioctylthiomethyl-6-methylphenol; 2,4-dioctylthiomethyl-6-ethylphenol; 2,6-didodecylthiomethyl-4-nonylphenol.

1.3 Hydroquinones and alkylated hydroquinones such as, for example: 2,6-di-t-butyl-4-methoxyphenol; 2,5-di-t-butylhydroquinone; <BR> <BR> <BR> <BR> <BR> 2,5-di-t-amylhydroquinone;<BR> <BR> <BR> <BR> <BR> <BR> <BR> 2,6-diphenyl-4-octadecyloxyphenol; 2,6-di-t-butylhydroquinone; 2,5-di-t-butyl-4-hydroxyanisole; 3,5-di-t-butyl-4-hydroxyanisole; 3,5-di-t-butyl-4-hydroxyphenyl stearate; bis (3,5-di-t-butyl-4-hydroxyphenyl) adipate.

1.4 Tocopherols such as, for example: a-tocopherol, $-tocopherol, y-tocopherol, b-tocopherol and their mixtures (Vitamin E).

1.5 Hydroxylated thiophenyl ethers such as, for

example: 2,2'-thiobis- (6-t-butyl-4-methylphenol); 2,2'-thiobis- (4-octylphenol); 4,4'-thiobis- (6-t-butyl-3-methylphenol); 4,4'-thiobis- (6-t-butyl-2-methylphenol); ; disulfide.

1.6 Alkylidene-bisphenols such as, for example: 2,2'-methylenebis- (6-t-butyl-4-methylphenol); 2,2'-methylenebis- (6-t-butyl-4-ethylphenol); 2,2'-methylenebis [4-methyl-6-(a-methylcyclohexyl)- phenol]; 2,2'-methylenebis (4-methyl-6-cyclohexylphenol); 2,2'-methylenebis (6-nonyl-4-methylphenol); 2,2'-methylenebis (4,6-di-t-butylphenol); 2,2'-ethylidenebis (4,6-di-t-butylphenol); 2,2'-ethylidenebis (6-t-butyl-4-isobutylphenol); 2,2'-methylenebis [6-(a-methylbenzyl)-4-nonylphe- nol]; 2,2'-methylenebis [6-(a,-dimethylbenzyl)-4-nonyl- phenol]; 4,4'-methylenebis (2,6-di-t-butylphenol); 4,4'-methylenebis (6-t-butyl-2-methylphenol); 1,1-bis- (5-t-butyl-4-hydroxy-2-methylphenyl)- butane;

2,6-bis- (3-t-butyl-5-methyl-2-hydroxybenzyl)-4- methylphenol; 1,1,3-tris- (5-t-butyl-4-hydroxy-2-methylphenyl)- butane; 1,1-bis- (5-t-butyl-4-hydroxy-2-methyl-phenyl)-3-n- dodecylmercaptobutane; ethyleneglycol bis [3,3-bis (3'-t-butyl-4'-hydroxy- phenyl) butyrate]; bis (3-t-butyl-4-hydroxy-5-methylphenyl) dicyclopen- tadiene; bis [2- (3'-t-butyl-2'-hydroxy-5'-methylbenzyl)-6-t- butyl-4-methylphenyl] terephthalate; 1,1-bis (3,5-dimethyl-2-hydroxyphenyl) butane; 2,2-bis (3,5-di-t-butyl-4-hydroxyphenyl) propane; 2,2-bis (5-t-butyl-4-hydroxy-2-methylphenyl)-4-n- dodecylmercaptobutane; 1,1,5,5-tetra (5-t-butyl-4-hydroxy-2-methylphenyl)- pentane.

1.7 Benzyl compounds containing O, N or S such as, for example: 3,5,3', 5'-tetra-t-butyl-4,4'-dihydroxydibenzyl ether; octadecyl-4-hydroxy-3,5-dimethylbenzylmercapto- acetate; tris (3,5-di-t-butyl-4-hydroxybenzyl) amine;

bis (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) dithio- terephthalate; bis (3,5-di-t-butyl-4-hydroxybenzyl) sulfide; iso-octyl-3,5-di-t-butyl-4-hydroxybenzylmercapto- acetate; 1.8 Hydroxybenzylated malonates such as, for example: dioctadecyl-2,2-bis (3,5-di-t-butyl-2-hydroxyben- zyl) malonate; <BR> <BR> <BR> <BR> <BR> dioctadecyl-2-(3-t-butrl-4-hydroxy-5-methylben-<BR> <BR> <BR> <BR> <BR> <BR> <BR> zyl) malonate; didodecylmercaptoethyl-2,2-bis (3,5-di-t-butyl-4- hydroxybenzyl) malonate; bis [4- (1,1,3,3-tetramethylbutyl) phenyl]-2,2- bis (3,5-di-t-butyl-4-hydroxybenzyl) malonate.

1.9 Aromatic hydroxybenzyl compounds such as, for example: 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl)-2,4,6- trimethylbenzene; 1,4-bis- (3,5-di-t-butyl-4-hydroxybenzyl)-2,3,5,6- tetramethylbenzene; 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) phenol.

1.10 Triazine compounds such as, for example: 2,4-bis (octylmercapto)-6- (3,5-di-t-butyl-4-hydro- xyaniline)-1,3,5-triazine; 2-octylmercapto-4,6-bis (3,5-di-t-butyl-4-hydro-

xyaniline)-1,3,5-triazine; 2-octylmercapto-4,6-bis (3,5-di-t-butyl-4-hydro- xyphenoxy)-1,3,5-triazine; 2,4,6-tris- (3, 5-di-t-butyl-4-hydroxyphenoxy)- 1,2,3-triazine; 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocya- nurate; 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylben- zyl) isocyanurate; 2,4,6-tris- (3,5-di-t-butyl-4-hydroxyphenylethyl)- 1,3,5-triazine; 1,3,5-tris (3,5-di-t-butyl-4-hydroxyphenylpropio- nyl)hexahydro-1,3,5-triazine; 1,3,5-tris- (3,5-dicyclohexyl-4-hydroxybenzyl) isocyanurate.

1.11 Benzylphosphonates such as, for example: dimethyl-2,5-di-t-butyl-4-hydroxybenzylphosphona- te; diethyl-3,5-di-t-butyl-4-hydroxybenzylphosphonate; dioctadecyl-3,5-di-t-butyl-4-hydroxybenzylphospho- nate; dioctadecyl-5-t-butyl-4-hydroxy-3-methylbenzylpho- sphonate; calcium salts of monoethyl ester of 3,5-di-t- butyl-4-hydroxybenzylphosphonic acid.

1.12 Acylaminophenols such as, for example: 4-hydroxylauranilide; 4-hydroxystearanilide; octyl-N- (3,5-di-t-butyl-4-hydroxyphenyl) carbamate.

1.13 Esters of 9- (3,5-di-t-butyl-4-hydroxyphenyl) pro- pionic acid with monohydric or polyhydric alcohols such as, for example: methanol, ethanol, octanol, octadecanol, 1,6-hexandiol, 1,9-nonandiol, ethyl- ene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, trie- thylene glycol, pentaerythritol, tris (hydroxy- ethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxami- de, 3-thioundecanol, 3-thiopentadecanol, trime- thylhexandiol, trimethylolpropane, 4-hydroxyme- thyl-1-phospho-2,6,7-trioxabicyclo [2.2 2] octane.

1.14 Esters of ß-(5-t-butyl-4-hydroxy-3-methylphe- nyl) propionic acid with monohydric or polyhydric alcohols such as, for example: methanol, ethanol, octanol, octadecanol, 1,6-hexandiol, 1,9-nonan- diol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxy- ethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxami- de, 3-thioundecanol, 3-thiopentadecanol, trime- thylhexandiol, trimethylolpropane, 4-hydroxyme-

thyl-l-phospho-2,6,7-trioxabicyclo [2.2.2] octane.

1.15 Esters of 9- (3,5-dicyclohexyl-4-hydroxyphenyl) pro- pionic acid with monohydric or polyhydric alcohols such as, for example: methanol, ethanol, octanol, octadecanol, 1,6-hexandiol, 1,9-nonandiol, ethyl- ene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triet- hylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3- thioundecanol, 3-thiopentadecanol, trimethylhexan- diol, trimethylolpropane, 4-hydroxymethyl-l- phospho-2,6,7-trioxabicyclo [2.2.2] octane.

1.16 Esters of (3,5-di-t-butyl-4-hydroxyphenyl) acetic acid with monohydric or polyhydric alcohols such as, for example: methanol, ethanol, octanol, octadecanol, 1,6-hexandiol, 1,9-nonandiol, ethyl- ene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, trie- thylene glycol, pentaerythritol, tris (hydroxye- thyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thioundecanol, 3-thiopentadecanol, trimethyl- hexandiol, trimethylolpropane, 4-hydroxymethyl-1- phospho-2,6,7-trioxabicyclo [2.2.2] octane.

1.17 Amides of 9- (3,5-di-t-butyl-4-hydroxyphenyl)- propionic acid such as, for example:

N, N'-bis (3,5-di-t-butyl-4-hydroxyphenylpropio- nyl)hexamethylenediamine; N, N'-bis (3,5-di-t-butyl-4-hydroxyphenylpropio- nyl)trimethylenediamine; N, N'-bis (3,5-di-t-butyl-4-hydroxyphenylpropio- nyl) hydrazine.

2. Ultra-violet ray and light stabilizers.

2.1 Derivatives of 2- (2'-hydroxyphenyl) benzotriazoles such as, for example: 2- (2'-hydroxy-5'methylphenyl)benzotriazole; 2- (3', 5'-di-t-butyl-2'-hydroxyphenyl) benzotriazo- le; 2- (5'-t-butyl-2'-hydroxyphenyl)benzotriazole; 2- [2'-hydroxy-5'- (1,1,3,3-tetramethylbutyl) phe- nyl] benzotriazole; 2- (3', 5'-di-t-butyl-2'-hydroxyphenyl)-5-chloroben- zotriazole; 2- (3'-t-butyl-2'-hydroxy-5'-methylphenyl)-5- chlorobenzotriazole; 2- (3'-sec-butyl-5'-t-butyl-2'-hydroxyphenyl) benzo- triazole; <BR> <BR> <BR> <BR> <BR> 2- (2'-hydroxy-4'-octyloxyphenyl)-benzotriazole;<BR> <BR> <BR> <BR> <BR> <BR> 2- (3', 5'-di-t-amyl-2'-hydroxyphenyl)-benzotriazo- le; 2- [3', 5'-bis (a, a-dimethylbenzyl)-2'-hydroxyphe-

nyl] benzotriazole; mixtures of 2- [3'-t-butyl-2'-hydroxy-5'- (2-octylo- xycarbonylethyl) phenyl)-5-chorobenzotriazole, 2- [3'-t-butyl-5'- (2- (2-ethylhexyloxy) carbonylethyl)- 2'-hydroxyphenyl]-5-chlorobenzotriazole, 2- [3'-t- butyl-2'-hydroxy-5'- (2-methoxycarbonylethyl) phe- nyl]-5-chlorobenzotriazole, 2- [3'-t-butyl-2'- hydroxy-5'- (2-methoxycarbonylethyl) phenyl] benzo- triazole, 2- [3'-t-butyl-2'-hydroxy-5'- (2-octylo- xycarbonylethyl) phenyl] benzotriazole, 2- [3'-t- <BR> <BR> <BR> <BR> <BR> butyl-5'- (2- (2-ethylhexyloxy) carbonylethyl)-2'-<BR> <BR> <BR> <BR> <BR> <BR> <BR> hydroxyphenyl) benzotriazole, 2- (3'-dodecyl-2'- hydroxy-5'-methylphenyl) benzotriazole and2- [3'-t- butyl-2'-hydroxy-5'- (2-iso-octyloxycarbonyl- ethyl) phenyl] benzotriazole, 2,2'-methylene-bis [4- (1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-yl- phenol]; esterification product of 2- [3'-t-butyl- 5'- (2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H- benzotriazole with polyethylene glycol 300; [R-CH2CH2-COO (CH2) 3] 2 wherein R = 3'-t-butyl-4- hydroxy-5'-2H-benzotriazol-2-yl-phenyl.

2.2 Derivatives of 2-hydroxybenzophenones such as, for example: 4-hydroxy- ; 4-methoxy- ; 4-octyloxy- ; 4- decyloxy- ; 4-dodecyloxy- ; 4-benzyloxy- ; 4,2', 4'- trihydroxy- ; 2'-hydroxy-4,4'-dimethoxy.

2.3 Esters of benzoic acids, optionally substituted, such as, for example: phenyl salicylate, 4-t- butylphenyl salicylate, octylphenyl salicylate, benzoyl-resorcinol, bis (4-t-butylbenzoyl)-resor- cinol, dibenzoyl-resorcinol, 2,4-di-t-butylphenyl- 3,5-di-t-butyl-4-hydroxybenzoate, hexadecyl-3,5- di-t-butyl-4-hydroxybenzoate, octadecyl-3,5-di-t- butyl-4-hydroxybenzoate, 2-methyl-4,6-di-t-butyl- phenyl-3,5-di-t-butyl-4-hydroxybenzoate.

2.4 Acrylates such as, for example, ethyl or isoctyl a-cyano-ß, ß-diphenylacrylate; methyla-carbometho- xycinnamate, methyl or butyl a-cyano-$-methyl-p- methoxycinnamate, methyla-carbomethoxy-p-methoxy- cinnamate, N-(ß-carbomethoxy-ß-cyanovinyl)-2- methylindoline.

2.5 Nickel compounds such as, for example, complexes of 3-tetramethylbutyl) phe- nol], for example 1: 1 or 1: 2 complexes, with or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, nickel salts of monoalkyl esters of 4-hydroxy-3,5-di-t-butyl- benzyl-phosphonic acid, such as methyl or ethyl esters, nickel complexes with ketoximes such as 2- hydroxy-4-methylphenyl undecyl ketoxime, nickel

complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazol with or without additional ligands.

2.6 Sterically hindered amines such as, for example: bis (2,2,6,6-tetramethyl-piperidyl) sebacate; bis (2,2,6,6-tetramethyl-piperidyl) succinate; poly-methylpropyl-3-oxy [4- (2,2,6,6-tetramethyl) pi- peridinyl] siloxane; poly-methylpropyl-3-oxy [4- (1,2,2,6,6-pentame- thyl) piperidinyl] siloxane; bis (1,2,2,6,6-pentamethyl-piperidyl) sebacate; bis (1,2,2,6,6-pentamethyl-piperidyl) n-butyl-3,5- di-t-butyl-4-hydroxybenzylmalonate; condensation product between 1- (2-hydroxyethyl)- 2,2,6,6-tetra-4-hydroxypiperidine and succinic acid; condensation product between N, N'-bis (2,2,6,6- tetramethyl-4-piperidyl) hexamethylenediamine and 5-triazine; tris (2,2,6,6-tetramethyl-4-piperidyl) nitrilotri- acetate; tetrakis (2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4- butane-tetracarboxylate; 1, 1'-(1,(1, 2-ethanodiyl) bis (3,3,5,5-tetramethyl- piperazinone; 4-benzoyl-2,2,6,6-tetramethylpiperidine;

4-stearyloxy-2,2,6,6-tetramethylpiperidine; bis (1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2- (2-hydroxy-3,5-di-t-butylbenzyl) malonate; 8-triazaspi- ro [4.5] decan-2,4-dione; bis (1-octyloxy-2,2,6,6-tetramethylpiperidyl) se- bacate; bis (1-octyloxy-2,2,6,6-tetramethylpiperidyl) suc- cinate; condensation product between N, N'-bis (2,2,6,6- tetramethyl-4-piperidyl) hexamethylenediamine and 5-triazine; condensation product between 2-chloro-4,6-di- (4-n- butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5- triazine and 1,2-bis (3-aminopropylamino) ethane; condensation product between 2-chloro-4,6-di- (4-n- butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5- triazine and 1,2-bis (3-aminopropylamino) ethane; 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3-8- triazaspiro [4.5] decano-2,4-dione; 3-dodecyl-l- (2,2,6,6-tetramethyl-4-piperi- dyl) pyrrolidin-2,5-dione; 3-dodecyl-1- (1,2,2,6,6-pentamethyl-4-piperi- dyl) pyrrolidin-2,5-dione.

2.7 Oxamides such as, for example:

4,4'-dioctyloxyoxanilide; 2,2'-diethoxyoxanilide; ; 2-ethoxy-2'-ethyloxanilide; N, N'-bis (3-dimethylaminopropyl) oxamide; 2-ethoxy-5-t-butyl-2'-ethoxanilide and its mix- tureswith2-ethoxy-2'-ethyl-5, 4'-di-t-butoxanili- de; and mixtures of disubstituted ortho-and para- methoxy anilides and mixtures of disubstituted ortho and para-ethoxy anilides.

2.8 2- (2-hydroxyphenyl)-1,3,5-triazines such as, for example: 2,4,6-tris (2-hydroxy-4-octyloxyphenyl)-1,3,5- triazine; 2- (2-hydroxy-4-octyloxyphenyl)-4,6-bis (2,4-dime- thylphenyl)-1,3,5-triazine; 2- (2,4-dihydroxyphenyl)-4,6-bis (2,4-dimethylphe- nyl)-1,3,5-triazine; 2,4-bis- (2-hydroxy-4-propyloxyphenyl)-6- (2,4- dimethylphenyl)-1,3,5-triazine; 2- (2-hydroxy)-4,6-bis (4-methylphenyl)-1,3,5- triazine; 2- (2-hydroxy-4-dodecyloxyphenyl)-4,6-bis (2,4- dimethylphenyl)-1,3,5-triazine;

2- [2-hydroxy-4- (2-hydroxy-3-butyloxypropoxy) phe- nyl]-4,6-bis 5-triazine; 2- [2-hydroxy-4- (2-hydroxy-3-octyloxypropyloxy)- phenyl]-4,6-bis 5-triazine.

3."Metal-deactivators"such as, for example: N, N- diphenyloxamide, N-salicylal-N'-salicyloyl-hydra- zine, N, N'-bis (salicyloyl) hydrazine; N, N'-bis (3,5- di-t-butyl-4-hydroxyphenylpropionyl) hydrazine, 3- salicyloylamino-1,2,4-triazole, bis (benzylidene) o- xalyl dihydrazide, oxanilide, isophthaloyl dihy- drazide, sebacoyl bisphenylhydrazide, N, N'-diace- tyladipoyl dihydrazide, N, N'-bis (salicyloyl) oxal- lyl dihydrazide, N, N'-bis (salicyloyl) thiopropionyl dihydrazide.

4. Phosphites and phosphonites such as, for example: triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris (nonylphenyl) phos- phite, trilauryl phosphite, trioctadecyl phos- phite, distearyl pentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis (2,4-di-t-butyl- phenyl) pentaerythritol diphosphite, bis (2,5-di-t- butyl-4-methylphenyl) pentaerythritol diphosphite, diisodecyloxypentaerythritoldiphosphite, bis (2,4- di-t-butyl-6-methylphenyl) pentaerythritol diphos-

phite, bis [2,4,5-tris (t-butylphenyl)] pentaerythri- tol diphosphite, tristearyl sorbitol triphosphite, tetrakis- (2,4-di-t-butyl-phenyl)-4,4'-diphenyle- nediphosphonite, 5-iso-octyloxy-2,4,8,10-tetra-t- butyl-12H-di-benzo [d, g]-1,3,2-dioxaphosphocine, 6- fluoro-2,4,8,10-tetra-t-butyl-12-methyl-diben- zo [d, g]-1,3,2-dioxaphosphocine, bis (2,4-di-t- butyl-6-methylphenyl) methylphosphite, bis (2,4-di- t-butyl-6-methylphenyl) ethylphosphite.

5. Agents which are capable of destroying peroxides such as, for example, esters of ß-thiodipropionic acid such as lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or zinc salt of 2- mercaptobenzimidazole, zinc dibutyldithiocarbama- te, dioctadecyldisulfide pentaerythritol tetrakis (S-dodecylmercapto) propionate.

6. Stabilizers of polyamides such as, for example, copper salts combined with compounds of iodine and/or phosphorous, divalent manganese salts.

7. Basic co-stabilizers such as, for example: mela- mine, polyvinylpyrrolidone, dicyanodiamide, triallyl cyanurate, derivatives of urea, deriva- tives of hydrazine, amines, polyamides, polyure- thanes, salts of alkaline metals and salts of earth-alkaline metals of fatty acids such as, for

example, Ca-stearate, Zn-stearate, Mg-stearate, Mg-behenate, Na-ricinoleate, K-palmitate, antimo- nium-pyrocatecholate, tin-pyrocatecholate.

8. Nucleating agents such as, for example: 4-t-butyl- benzoic acid, adipic acid, diphenylacetic acid.

9. Fillers and reinforcing agents such as, for example: calcium carbonate, silicates, glass fibres, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite.

10. Other additives such as, for example: plastici- zers, lubricants, emulsifying agents, pigments, optical brighteners, flame-retardants (for exam- ple, bromides, chlorides, phosphorates and phos- phorous/halogen mixtures), antistatic agents, blowing agents, thiosynergizing agents such as, for example, dilauryl thiodipropionate or diste- aryl thiodipropionate.

11. Benzofuranones and indolinones such as, for example: 3- [4- (2-acetoxyethoxy) phenyl]-5,7-di-t-butylben- zofuran-2-one; 5,7-di-t-butyl-3- [4- (2-stearoyloxyethoxy) phe- nyl]benzofuran-2-one; 3,3'-bis [5,7-di-t-butyl-3- [4- (2-hydroxyethoxy) phe-

nyl] benzofuran-2-one]; 5,7-di-t-butyl-3- (4-ethoxyphenyl) benzofuran-2-one; 3- (4-acetoxy-3,5-dimethylphenyl)-5,7-di-t-butyl- benzofuran-2-one; 3- (3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-t- butyl-benzofuran-2-one; or those described in U. S. patents 4.325.863, 4.338.244,5.175.312,5.216.052,5.252.643, 4.316.611,4.316.622,4.316.876 or in European patent applications 589.839 and 591.102.

Some illustrative but non-limiting examples are provided hereunder for a better understanding of the present invention and for its embodiment.

EXAMPLE 1 Preparation of $-methoxyethylamino crotonate of 4- (2,2,6,6-tetramethyl) piperidinyl (Compound Nr. 1) having the following formula: 24.13 g (0.1 moles) of 2,2,6,6-tetramethyl-4-pi- peridinyl-acetoacetate, 24 g of toluene, 7.51 g (0. 1 moles) of 2-methoxyethylamine and 0.23 g of glacial acetic acid, are charged into a 250 ml four-necked

reactor, equipped with a stirrer, thermometer and reflux condenser with a water separator.

The reaction mass is maintained under stirring and reflux heated for 4 hours, to a temperature ranging from 115°C to 118°C. During this period there is the formation of reaction water which is separated by azeotropic distillation: 1.5 g of reaction water are separated.

The solvent and acetic acid are removed by distil- lation and the raw residue thus obtained is subjected to fractionated distillation.

This distillation is carried out in a distiller consisting of a 100 ml boiler equipped with a thermome- ter, stirrer, column, condenser and device for the collection of fractions.

A central fraction containing 26.6 g of distilled product corresponding tc Compound Nr. 1, is collected from the above distillation, operating under the following conditions: -temperature at the head: 146°C-151°C; -temperature of the boiler: 148°C-152°C; -vacuum: 0.1 mm/Hg.

Compound Nr. 1 thus obtained, analyzed by gas- chromatography (GC), proves to be 97.5% pure, with a yield of about 89.2%.

Compound Nr. 1 is characterized by NMR analysis which confirms its enamine structure. <BR> <BR> <P>-1H-NMR (200 MHz, CDC1 3-TMS) 6 (ppm): NH (broad) 8.50 ppm; C=CH (s) 4.34 ppm; the other signals are in accordance with the structure.

The other compounds (Compounds Nr. 2-5) are prepared analogously to Example 1, of which only the reaction conditions and characteristics are specified.

EXAMPLE 2 Preparation of ß-(2,2,6,6,-tetramethylpiperidin-4- amino) ethyl crotonate (Compound Nr. 2) having the following formula: -Amine: 4-amino-2,2,6,6-tetramethylpiperidine; 31.25 g (0.2 moles).

-Carbonyl compound: ethyl aceto-acetate; 26.03 g (0.2 moles).

-Solvent: toluene; 50 g.

-Catalyst: acetic acid; 0.3 g -Reaction water separated: 3.3 g

-Duration and reaction temperature: 5 hours at<BR> <BR> 126°C-128°C.

-Distillation range: 118°C-133°C (head); 130°C- 144°C (boiler); 0.10 mm/Hg-0.15 mm/Hg (vacuum).

Product obtained: 47.5 g.

-GC Purity: 98.9%.

-Yield: 88.4% <BR> <BR> -1H-NMR (200 MHz, CDC13-TMS) 6 (ppm): NH (d) 8.39 ppm; C=CH (s) 4.35 ppm; the other signals are in accordance with the structure.

EXAMPLE 3 Preparation of J3- (2,2,6,6,-tetramethyl) piperidin-4- amino) crotonate of 4- (2,2,6,6-tetramethyl) piperidinyl (Compound Nr. 3) having the following formula: -Amine: 4-amino-2,2,6,6-tetramethylpiperidine; 31.25 g (0.2 moles).

-Carbonylcompound:2,2,6,6-tetramethyl-4-piperidi- nylacetoacetate; 48.5 g (0.2 moles).

-Solvent: toluene; 50 g.

-Catalyst: acetic acid; 0.3 g -Reaction water separated: 3.44 g -Reaction time and temperature: 3.5 hours at 114°C- 128°C.

In this case the raw residue obtained is not subjected to fractionated distillation as the end- product crystallizes in the reaction medium at room temperature. When the crystallization is complete, the product obtained is filtered, washed with toluene and dried.

-Product obtained: 41.4 g.

-GC Purity: 98.9%.

-Yield: 54.4% <BR> <BR> <BR> <BR> <BR> -1H-NMR (200 MHz, CDCl3-TMS) 6 (ppm): NH (d) 8.32 ppm; C=CH (s) 4.30 ppm; the other signals are in accordance with the structure.

-Melting point: 151°C.

EXAMPLE 4 Preparation of S-octadecylamino ethyl crotonate (Com- pound Nr. 4) having the following formula: -Amine: octadecylamine; 53.9 g (0.2 moles).

-Carbonyl compound: ethyl acetoacetate; 26.03 g

(0.2 moles).

Solvent: toluene; 50 g.

-Catalyst: acetic acid; 0.3 g -Reaction water separated: 3.50 g -Reaction time and temperature: 1 hour 45 minutes at 118°C-130°C.

The product is isolated as boiler residue after distillation under vacuum of the solvent and acetic acid.

-Product obtained: 75 g.

-GC Purity: 98.2%.

-Yield: 98.3% -Melting point: 40.5°C Compound Nr. 4 is characterized by NMR analysis which confirms its enamine structure. <BR> <BR> <BR> <BR> <BR> <P>-1H-NMR (200 MHz, CDCl3-TMS) 6 (ppm): NH (broad) 8.53 ppm; C=CH (s) 4.40 ppm; the other signals are in accordance with the structure.

EXAMPLE 5 Preparation of 9- (2-methoxyethylamino) ethyl crotonate (Compound Nr. 5) having the following formula: -Amine: 2-methoxyethylamine; 75.11 g (1 mole).

-Carbonyl compound: ethyl acetoacetate; 130.14 g (1

mole).

-Solvent: toluene; 100 g.

-Catalyst: acetic acid; 2.33 g -Reaction water separated: 20.20 g -Reaction time and temperature: 4 hours at 130°C- 150°C.

-Distillation range: 89°C-92°C (head); 110°C-130°C (boiler); 0.1-0.2 mm/Hg (vacuum).

-Product obtained: 153 g.

-GC Purity: > 99%.

-Yield: 81.7% <BR> <BR> <BR> <BR> -1H-NMR (200 MHz, CDCl3-TMS) b (ppm): NH (d) 8.58 N- H; 4.36 (H-C).

EXAMPLE 6 Evaluation of the W light fatigue resistance of a mixture of a photochromatic compound and an enamine.

A 2.5 x 10-3 M solution of Variacrol Red PNO sold by Great Lakes, was prepared.

Four 10 ml portions of the above solution were removed and the following additions were effected: (a) no addition; (b) Compound Nr. 5 (obtained as described in Example 5); (c) Compound Nr. 1 (obtained as described in Example 1);

(d) Tinuvin 770 sold by Ciba.

The quantities of compounds added in (b), (c) and (d) are equal to 1 x 10-2 M (equal to a ratio 1: 4 between photochromatic compound/stabilizing compound).

The four solutions are charged into a W circular reactor with six lamps (iman = 320 nm) and are subjected to continuous radiation for several hours.

Samples were taken at intervals of 24,48 and 144 hours and the percentage of photochromatic product still present in the solution was determined by gas- chromatography operating under the following condi- tions: -5890 Series II instrument of Hewlett Packard; -HP 1 semicapillary column (length 15 mt; internal diameter 0.53 mm; film thickness 10); -injection temperature: 90°C; -oven program: 5'at 90°C; from 90°C to 290°C with gradient of 15°C/min; final isotherm: 30'at 290°C; -injection: 0.1 Al of the above solutions at 0.1% in methylene chloride.

The results of the chromatographic analysis are indicated in Table 1.

<BR> <P> TABLE 1 RADIATION TIME REMAINING VARIACROL RED PNO (h) (%) (a) (b) (c) (d) 24 30.60 85.48 83.26 78.55 48 10.10 76.12 71.35 40.56 144 0 57.06 39.71 0 <BR> <BR> <BR> <BR> EXAMPLE 7<BR> Evaluation of the UV light fatigue resistance of a mixture of a photochromatic compound and an enamine.

A 1 x 10-4 M solution of the photochromatic com- pound having formula (VIA), was prepared.

Three 7 ml portions of the above solution were removed and the following additions were effected: (a) no addition; (b) Tinuvin 770 sold by Ciba; (c) Compound Nr. 1 (obtained as described in Example 1); The quantities of compounds added in (b) and (c) <BR> <BR> are equal to 3 x 10-4 M (equal to a ratio of 1: 3 between photochromatic compound/stabilizing compound).

The deterioration of the photochromatic activity was determined by measuring the AY which corresponds to

the difference between the Luminous Transmittance values (Y), before and after activation with a WA lamp, irradiance equal to 9 W/m2,60 seconds of radia- tion; Y corresponds to the value of the tristimulus colorimetry which indicates the Luminous Transmittance value in the visible region, as defined in Regulation CIE 1931 (this value is obtained by mathematical processing of the absorption spectra of the two acti- vated and deactivated forms).

Table 2 indicates the AY at time 0 and after 40' of radiation in a reactor as described in Example 6.

TABLE 2 <BR> <BR> <BR> <BR> <BR> <BR> TIME #Y<BR> (min.) (a) (b) (c) 0 31.29 31.29 31.29 40'0 14.25 18.39 <BR> <BR> <BR> <BR> <BR> <BR> EXAMPLE 8<BR> Evaluation of the light fatigue resistance of photo- chromatic lenses.

Three photochromatic lenses are prepared according to the process described in patent application MI 92/A 002492.

The allyl carbonate used is obtained from the reaction of diallyl carbonate (DAC) with a mixture of neopentyl glycol (NPG) and tris (hydroxyethyl) isocyan- urate (THEIC) in the following proportions: NPG 70% by weight; THEIC 30% by weight; molar ratio DAC/ (NPG+THEIC) = 5/1.

The product thus obtained is a complex mixture containing: -bis (allyl carbonate) of neopentyl glycol, monomer and oligomers; -tris (allyl carbonate) of tris (hydroxyethyl) iso- cyanurate, monomer and oligomers; -mixed allyl carbonates of neopentyl glycol and tris (hydroxyethyl) isocyanurate.

The above product has the following physico- chemical characteristics: -Viscosity 25°C (cst): 80.

-Density, 20°C (g/ml): 1.1411. nD20: 1.4595 The polymerizable liquid compositions are prepared by mixing and homogenizing allyl carbonate (98.4%), perketal 1,1-di (ter-butylperoxy)-3,3,5-trimethylcyclo- hexane (1.5%), the photochromatic compound Variacrol Red PNO and compounds Nr. 1, Nr. 2, Nr. 3 and Nr. 4, obtained as described above.

The photochromatic compound Variacrol Red PNO° and compounds Nr. 1, Nr. 2, Nr. 3 and Nr. 4 are added to the above liquid compositions, in the following quanti- ties: (a) 0.1% of Variacrol Red PNO@; (b) 0.1% of Variacrol Red PNO and 0.6% of Compound Nr. 1; (c) 0.1% of Variacrol Red PNO° and 0.6% of Compound Nr. 2; (d) 0.1% of Variacrol Red PNOO and 0.6% of Compound Nr. 4; (e) 0.1% of Variacrol Red PNOs and 0.6% of Compound Nr. 3.

The compositions thus obtained are transformed by polymerization into lenses with a thickness of 2 mm, using the conventional"casting"technique. According to this technique the liquid composition containing the catalyst is poured into the cavity of a mould consist- ing of two glass elements, with a seal made of plastic- ized polyvinylchloride or ethylene-vinyl acetate (EVA) copolymer.

The liquid composition is subjected to polymeriza- tion in the mould by means of thermal treatment, in a forced circulation oven, for 5 hours at 85°C, over 15 hours at 90°C and a further 7 hours at 100°C. At the

end of this treatment, the moulds are opened, the polymerized products are recovered and the photochrom- atic properties are determined on the photochromatic lenses thus obtained, by recording the UVA-visible spectra at 23°C of the deactivated and activated forms, using a Hewlett Packard HP8452A spectrophotometer (activation for 60 seconds of radiation with a UVA lamp having 9W/m2 of irradiance). The luminous transmittance values (Y) of the deactivated and activated forms (AY), are recorded.

These lenses are subsequently subjected to accel- erated aging in an Atlas CI 65 Weatherometer (WOM) under the following conditions: -temperature of the black panel: 60°C; -radiation: 0.33 W/m2 at 340 nm; -relative humidity: 50%.

The photochromatic activity of the lenses ex- pressed as AY is measured again at various intervals of time and the percentage loss of photochromatic activity itself is determined (% loss of AY). The % loss of AY is indicated in Table 3.

<BR> <P> TABLE 3 WOM % LOSS OF AY (h) (a) (b) (c) (d) (e) <BR> <BR> <BR> <BR> 0 0 0 0 0 0<BR> 49 25.7 26.9 16.7 23.6 22.3 106 41.1 34.5 34.8 37.9 32.4 224 65.0 60.5 54.7 61.6 55.2 270 66.2 62.9 58.3 63.9 55.4