SOLID PARTICLE DISPERSION FILTER DYES FOR PHOTOGRAPHIC COMPOSITIONS Field of the Invention

This inυention relates to dyes, particularly dyes useful as filter dyes, especially in photogra¬ phic compositions and elements . Background of the Invention

Photographic materials often contain filter dyes to absorb light from different regions of the spectrum, such as red, blue, green, ultraviolet, and infrared, to name a feuj. These filter dyes are often required to perform the function of absorbing light during exposure of the material so as to prevent or at least inhibit light of a region of the spectrum from reaching at least one of the radiation-sensitive layers of the element.

After processing of the element, however, the continued presence of the filter dye will adversely affect the image quality of the photo— graphic material. It is therefore desirable to use filter dyes that will be solubilized and removed or at least decolorized during photographic processing. Dyes that are easily solubilized, however, tend to wander throughout the photographic material during coating, adversely affecting the final image quality. To prevent dye wandering, the dyes are often coated with a mordant to bind the dye in the layer in which it is coated. Dye mordants, while often useful, tend to either bind the dye too strongly, inhibiting removal of the dye during photographic processing, or too weakly, thus not preventing dye wandering .

Lemahieu et al describe in U.S. Patent 4,092,168 a combination of specific monomethine oxonol and penta ethine oxonol dyes useful as antihalation dyes . The dyes are insoluble at coating pH ' s, thus eliminating the need for a dye mordant,

and are soluble for removal and/or decolorization at processing pH's. These dyes are disclosed as being dispersible as solid particles in aqueous hydrophilic colloid compositions; however, no suggestion is given that any other dyes might possess the same beneficial solubility properties. The reference discusses the absorbance properties of the dyes and their suitability for antihalation use, but no teaching whatsoever is presented as to what other dyes might possess the beneficial solubility properties of being aqueous—insoluble at coating pH' s and highly aqueous-soluble at processing pH's. There is also no teaching that would enable anyone as to how to choose dyes other than those specifically disclosed in the U.S. Patent 4,092,168 to obtain those properties. Kreuger et al describe in U.S. Patent 4,420,555 specific yellow filter dyes for incorporation into film—forming polymeric binders in photographic elements , The dyes are preferably incorporated in the binders in loaded polymeric latexes. These dyes are disclosed as being removable and/or decolorizable during photographic processing. The dyes are not disclosed as being coatable as solid particle dispersions and, as with U.S. Patent 4,092,168, there is no teaching or suggestion that any dyes other than those specifically disclosed (or, for that matter, even the dyes disclosed therein) might possess the beneficial concomitant advantages of being aqueous—insoluble at coating pH' s and aqueous—soluble at processing pH' s .

Prior to the present invention, there has been a lack of recognition in the prior art that there might exist a broad class of dyes having a specific set of properties that allow them to be prepared and incorporated into photographic compositions and elements as solid particle

dispersions that are aqueous-insoluble at coating pH ' s and aqueous—soluble at photographic processing pH's. It would, of course, be highly desirable to provide a broad class of filter dyes for use in photographic elements that do not wander during coating, are fully solubilized during processing, and do not require a mordant.

It has now been discovered that a broad class of dyes, where the dye and its substituents are chosen so as to meet a specific combination of solubility criteria for both acid/base and nonpolar/polar systems, can be prepared as solid particle dispersions having the above—described beneficial solubility properties. Summary of the Invention

These solid particle dispersions are dyes of the formula:

(I) [D-(A) ]-X

where D is a chromophoric light-absorbing compound, which may or may not comprise an aromatic ring if y is not 0 and which comprises an aromatic ring if y is 0, A is an aromatic ring bonded directly or indirectly to D, X is a substituent, either on A or on an aromatic ring portion of D, with an ionizable proton, y is 0 to 4, and n is 1 to 7, where the dye is substantially aqueous insoluble at a pH of 6 or below and substantially aqueous soluble at a pH of 8 or above.

Specifically excluded from dye dispersions of the invention are the dispersions of prior art dyes and obvious variations thereof known to be used as solid particle dispersions. These dyes comprise those according to U.S. Patent 4,092,168, which have the formula:

O OH

where R 1 and R2 each independently represents an

3 4 alkyl group or an aryl group, R and R each independently represents an alkyl group, an aryl group, or COOR where R is alkyl or aryl, m is 0 and

2, and the molecule contains at least two carboxyl groups in their free acid form and further contains no solubilizing groups.

Although U.S. Patent 4,092,168 discloses specific dyes having the above— escribed beneficial solubility properties, it and the rest of the prior art does not provide any disclosure that would enable one skilled in the art to determine other dyes that would have the same beneficial properties. The present invention provides that enabling disclosure. It has now been found that dyes of formula (I) will be substantially insoluble at pH's of 6 or below and substantially soluble at pH's of 8 or above when X has a p a in a 50/50 mixture (volume basis) of ethanol and water of from 4 to 11 and when the nonionized (neutral) dye has a log partition coefficient (log P) of from 0 to 6.

The dye dispersions of the invention are coatable in hydrophilic vehicle (e.g., gelatin) layers of photographic elements, and do not require a mordant to prevent them from wandering at the normal coating pH ' s of 6 or below (usually 4 to 6). At the normal photographic processing pH' s of 8 and above (usually 8 to 12), however, the dye dispersions are highly soluble, allowing them to be easily removed and/or decolorized.

Detailed Description of the Invention

The chromophoric light-absorbing compound, D, of formula (I) can be any of a number of well-known dye compounds. These include cyanines, erocyanines , oxonols, arylidenes (i.e., erostyryls) , anthraquinones, triphenylmethanes, azo dye types, azo ethines, and others. The specific dye used is not critical, as long as all the criteria of formula (I) are met. These dyes are commonly used in the photographic art, and are more fully described in James, The Theory of the Photographic Process, 4th, Macmillan, New York (1977) and Hamer, The Cyanine Dyes and Related Compounds, Interscience (1964). The cyanine dyes include, joined by a methine linkage, two basic heterocyclic nuclei, such as those derived from quinolinium, pyridinium, isoquinoliniu , 3H-indolium, benz[e]indolium, oxazoliu , thiazolium, selenazolinium, imidazolium, benzoxazoliniu , benzothiazolium, benzoselenazolium, benzimidazolium, naphthoxazolium, naphthothiazolium, naphthoselenazolium, thiazolinium dihydronaphthothiazolium, pyrylium, and imidazopyrazinium quaternary salts .

The merocyanine dyes include, joined by a methine linkage, a basic heterocyclic nucleus of the cyanine dye type and an acidic nucleus, such as can be derived from barbituric acid, 2—thiobarbituric acid, rhodanine, hydantoin, 2—thiohydantoin, 4—thiohydantoin, 2-pyrazolin-5-one, 2-isoxazolin- 5—one, indan—1,3—dione, cyclohexan—1,3—dione, 1, 3-dioxan-4,6-dione, py azolin-3, 5-dione, pentan-2,4-dione, alkylsulfonyl acetonitrile, malononitrile, isoquinolin-4—one, and chroman-2,4—dione . The oxonol dyes include, joined by a methine or bridged methine linkage, two acidic carbo- or

heterocyclic nuclei, such as those described above for rnerocyanine dyes, with the exclusion of 2—pyrazolin—5—one.

The arylidene dyes include, joined by a methine or bridged methine linkage, an acidic nucleus as described previously and an aryl group, substituted with electron—donating substituents, such as alkyl— or dialkylamino, methoxy, and the like. The anthraquinone dyes include those compounds derived from the anthraquinone nucleus and substituted with electron donating or electron withdrawing groups so as to extend the chromophoric nature of the compound.

The triphenyl ethane dyes include those compounds with three aryl groups joined to a single methine linkage and substituted with suitable electron—donating or electron— ithdrawing substituents so as to produce an extended chromophoric system. The azo dyes include any of a large class of compounds with two nitrogens in the linkage between multiply—substituted aryl groups, as is known in the art.

The azomethine dyes include, joined by a single nitrogen in the unsaturated linkage, an acidic nucleus as described previously for the rnerocyanine dyes, and an aryl group substituted with electron-donating substituents such as alkyl— or dialkylamino, methoxy, and the like. All the above—described chromophoric light—absorbing compounds are well— nown in the art. Additional examples of these and other dye classes suitable for use in this invention are disclosed in the Colour Index 3d, The Society of Dyers and Colourists, Great Britain (1971).

The aromatic ring (A or an aromatic ring, to which X is attached, that is part of D) of formula (I) can be any aromatic ring capable of bonding with D and X in a manner such that the proper pKa and log P are achieved. Examples of such rings include phenyl, naphthyl, anthracenyl, pyridyl, acenaphthyl, dihydronaphthyl, and pyrimidyl. The aromatic ring A, if present, may be bonded directly to D or indirectly (i.e., through a divalent linking group, such as alkyl, as is known in the art) to D.

The substituent, X, of formula (I) having an ionizable proton with a pKa in a 50/50 mixture (volume basis) of ethanol and water of from 4 to 11, when attached to the aromatic ring of formula (I), can be easily chosen by one skilled in the art.

Especially preferred substituents are carboxyl and sulfonamido (especially NHS0_R where R is a substituted or unsubstituted alkyl group of from 1 to 6 carbon atoms) . The pKa of the compounds of formula (I) in a

50/50 mixture (volume basis) of ethanol and water is preferably from 4 to 11. The pKa parameter is a well—known measurement of the dissociation constant of an ionizable compound in aqueous environments . It is discussed in most basic chemistry texts and does not require further explanation here. The log partition coefficient (log P) of the unionized (i.e., neutral) compounds of formula (I) is preferably from 0 to 6. The log P parameter is a well-known measurement of the solubility of a compound in aqueous liquids compared to its solubility in nonpolar organic solvents. The log P parameter is further described, along with log P data for organic compounds, in C. Hansch & T. Fujita, J. Am. Chem. Soc, .86, 1616-25 (1964) and A. Leo & C. Hansch, Substituent Constants for Correlation Analysis in Chemistry and Biology, Wiley, New York (1979).

Examples of compounds according to formula (I) are presented in the following Tables I-_. Except where stated otherwise, absorbance data are given for the dye in methanol.

Table I Pyrazolone Cinnamylidene Dyes General Structure:

R ²

Dye R 1 R2 R3 λ.-max e-max (x 104) (methanol)

1 CH ₃ H C0 ₂ H 516 4.62

2 CH ₃ C0 H CO H 573 5.56

3 CO Et H CO H 576 5.76

4 CH ₃ C0 ₂ H H 506 3.90

5 C0 ₂ Et C0 ₂ H H 560 5.25

Table II

Benzoylacetonitrile Merocyanines General Structure:

C ₂ H ₅

Dye λ—max ε—max (x 10*)

(methanc »1>

6 n-C ₆ H ₁₃ S0 ₂ NH CH ₃ 445 7 .32

7 CH ₃ S0 ₂ H C ₃ H ₇ 446 7, ,86

8 CH ₃ S0 ₂ H n-C _fi H 13 447 7. ,6

9 H CH 449 6. 5

Table II-A

Arylidene Dyes

General Structure

Dye R λ-rnax ε— ax (x 10 )

(methanol)

10 H 424 3.98

11 CH. 423 3.86

Table III

General Structure:

Dye R λ—max e— ax (x 10 )

(meth ^, anol)

12 i-Pr0 ₂ CCH ₂ i- Pr0 ₂ CCH ₂ C ₃ H _? 426 3. 5

13 439 4. 27

^C 2 ^H 5 CH.

^CF 3 ^CH 2°2 ^CCH 2

14 i-Pr0 ₂ CCH ₂ •Pr0 ₂ CCH ₃ CH. 420 4. 2

15 C ₂ H ₅ CF ₃ CH ₂ 0 ₂ CCH ₂ C ₃ H _? 430 4. 25

Table IU Pyrazolone Merocyanines

General Structure:

R ³

Dye R ¹ R ² R ³ R ^{4 '} λ-max εmax (x 10 ⁴ )

(methanol)

16 C . CH, H CO H 450 7.4

2 5 3 2

17 C Z-H Ώ _c CH._S CO Z_H H 452 7.19

R ³

λ.—max 562 n ε—max = 11.9 x 10

(methanol)

Table U Barbituric Acid Merocyanines General Structure:

1 7 3 4

Dye R R R λ-max ε-max (x 10 )

(methanol) 19 CH Δ„PhCO Δ„H C-H 3 _c C H _C _3 442 10.70

Table UI

General Structure:

^R 2

Dye R ¹ R ² R ³

20 — Et MeOEtSO NH

21 — Me MeS0 ₂ NH

22 Me0EtS0 ₂ NH Et MeOEtS0 ₂ NH

23 MeOEtSO NH Et HexS0 ₂ NH

24 MeS0 ₂ NH MeOEt MeS0 ₂ NH

25 — CH ₂ ,PhCC PrSO NH

'2 ^H

26 MeSO NH MeOEt PrSO NH

27 MeOEtS0 ₂ NH MeOEt PrSO NH

28 EtS0 ₂ NH Et MeS0 ₂ NH

29 EtS0 _Λ NH Me MeSO NH 2

30 Me0EtS0 ₂ NH MeOEt MeOEtS0 ₂ NH

31 HexS0 ₂ NH MeOEt MeS0 ₂ NH

32 Me0EtS0 ₂ NH MeOEt HexS0 ₂ NH

34 MeS0 ₂ NH Me MeS0 ₂ NH

35 C0 ₂ H Me MeS0 ₂ NH

36 C0 ₂ H Me PrS0 ₂ NH

37 Et0Et0EtS0 ₂ NH Et MeS0 ₂ NH

38 EtOEtOEtS0 ₂ NH Et PrS0 ₂ NH

39 PrS0 ₂ NH Et MeS0 ₂ NH

40 PrS0 ₂ NH Me MeS0 ₂ NH

41 MeSQ ₂ NH Et EtS0 ₂ NH

42 EtS0 ₂ NH Et EtS0 ₂ NH

43 BuS0 ₂ NH Et MeS0 ₂ NH

44 BuS0 ₂ NH Et C0 ₂ H

45 BuS0 ₂ NH Me MeS0 ₂ NH

46 MeS0 ₂ NH Et BuS0 ₂ NH

Tabl.e UII

Miscellaneous Dyes

λ.— max = 502 n ε-max = 5 . 47 x 10

o oo -S3 f I-* »-* m O un O in O in

CN

25 λ-max = 500 n

4 ε-max = 5.82 x 10

30

35

Table UIII

1arylidene Dyes

General Structure :

1-Ph e—

. Subst .n . x λ—max

Dye R ¹ . R ² R ³ R Position n (nm) (1

56 _H ₃ H CH ₃ 1 4 0 466 3

57 H CH ₃ 1 4 0 471 4

^C 2 ^H 5

58 n-C H H CH 1 4 0 475 4 4 9 3

59 CH H COOC H 1 4 0 508 5 3 2 5

60 i-C ₃ H ₇ OCVCH CH ₃ CH 1 4 0 430 3 3

61 CH ₃ H CH ₃ 2 3,5 0 457 3

62 H CH ₃ 2 3,5 0 475 4

^C 2 ^H 5

63 n-04 _Λ ^H _n H CH ₃ 2 3,5 0 477 4 9

64 i-C-,H„ OCC CH ₃ 2 3,5 0 420 3 3 7 VH,, H

65 i-C H OCCH CH CH 2 3,5 0 434 3 3 7 3 3

66 i- ₃ H ₇ OC CH„ H CH ₃ 1 4 0 420 3 2

0

II

67 CH ₃ H C CH ₃ 1 4 1 573 5

68 CH ₃ H COOEt 1 3,5 0 502 4

69 C ₂ H. H COOEt 1 4 0 512 6

70 CH ₃ H 1 4 0 507 4

^CF 3

71 CH ₃ H Ph 1 4 0 477 4.

72 CH, H ϊ C CH, 1 4 0 506 5.

00 00 ro in O in o ro in σ in

CD 00 oo to o lO CD

00 00 00 oo 00

CΛ in * CO

oo ro ro in O in O in O in

»-_> ID ID oo oo ro o 00

co co ro to t-* i-* un O O in O in O m

o ' o o o

U_> 00 --3 O.

CO oo ro ro in O in O in in

oo ro O

CO co ro ro in O n O in in

CO

illustrated by the synthetic examples below. Such techniques are further illustrated, for example, in "The Cyanine Dyes and Related Compounds", Frances Hamer, Interscience Publishers, 1964. The dye compounds of formula (I) are utilized in the form of a solid particle dispersion (i.e., the dye is in the form of solid particles of microscopic size). The dispersion can be in any υehicle in which the dye is not soluble, such as an aqueous liquid haυing a pH low enough for the dye to be insoluble (e.g., a gelatin coating solution), an organic solυent in which the dye is insoluble, a monomer, or a polymeric binder. The dispersion is useful for incorporation into a layer haυing a polymeric film—forming binder known in the art (e.g., a hydrophilic colloid binder) a photographic element. The dyes may be located in any layer of the element where it is desirable to absorb light, but it is particularly adυantageous to locate them in a layer where they will be solubilized and washed out during processing. Useful amounts of dye range from

2

1 to 1000 mg/ft . The dye should be present in an amount sufficient to yield an optical density at the transmission D— ax in the υisible region before processing of at least 0.10 density units and preferably at least 0.30 density units. This optical density will generally be less than 5.0 density units for most photographic applications.

The solid particle dispersion can be formed by precipitating or by reprecipitating the dye in the form of a dispersion and/or by well-known milling techniques, e.g., ball— illing, sand— illing, or colloid-milling the solid dye in the presence of a dispersing agent. Reprecipitating techniques by dissolυing the dye and precipitating by changing the solυent and/or the pH of the solution in the presence of a surfactant are well—known in the art. Milling techniques are well-known in the art and are described, for example in U.S. Patent 4,006,025. The dye particles in the dispersion should haυe a mean diameter of less than 10 μm and preferably less

than 1 μm. The dye particles can be conυeniently prepared in siz.es ranging down to about 0.01 μm or less.

The support of the element of the inυention can be any of a number of well-known supports for photographic elements . These include polymeric films such as cellulose esters (e.g., cellulose triacetate and diacetate) and polyesters of dibasic aromatic carboxylic acids with diυalent alcohols (e.g., pol (ethylene terephthalate)) , paper, and polymer- coated paper. Such supports are described in further detail in Research Disclosure, December, 1978, Item 17643 [hereinaf er referred to as Research Disclosure] , Section XVII. The radiation—sensitiυe layer of the element of the inυention can contain any of the known radiation—sensitiυe materials, such as εilυer halide, diazo image-forming systems, light—sensitiυe tellurium-containing compounds, light—sensitiυe cobalt-containing compounds, and others described in, for example, J. Kosar, Light-Sensitiυe Systems: Chemistry and Application of Nonsilυer Halide Photographic Processes, J. Wiley & Sons, N.Y. (1965).. Silυer halide is especially preferred as a radiation—sensitiυe material. Silυer halide emulsions can contain, for example, silυer bromide, silυer chloride; silυer iodide, silυer chlorobro ide, silυer chloroiodide, silυer bromoiodide, or mixtures thereof. The emulsions can include coarse, medium, or fine εilυer halide grains bounded by 100, 111, or 110 crystal planes. Silυer halide emulsions and their preparation are further described in Research Disclosure, Section I. Also useful are tabular grain silυer halide emulsions, as described in Research Disclosure, January, 1983, Item 22534 and U.S. Patent 4,425,426.

The radiation—sensitiυe materials described aboυe can be sensitized to a particular waυelength range of radiation, such as the red, blue, or green portions of the υisible spectrum, or to other waυelength ranges, such as ultraυiolet, infrared. X-ray, and the like. Sensitization of silυer halide can be accomplished with chemical sensitizers such as gold compounds, iridium compounds, or other group VIII metal compounds, or with spectral sensitizing dyes such as cyanine dyes, merocyanine dyes, styryls, or other known spectral sensitizers. Additional information on sensitization of silυer halide is described in Research Disclosure, Sections I-IU.

The dyes of formula (I) are useful in many applications requiring the use of a filter dye. For example, they can be used as interlayer dyes, trimmer dyes, antihalation dyes, or pelloid dyes. They can be used to preυent crossoυer in X—ray materials, to preυent unwanted blue light from reaching the green-sensitiυe emulsion layer of a multicolor photographic element, and other uses as indicated by the absorbance spectrum of the particular dye. The dyes can be used in a separate filter layer or as an intergrain absorber. Multicolor photographic elements according to the inυention generally comprise a blue-sensitiυe silυer halide layer haυing a yellow color—forming coupler associated therewith, a green-sensitiυe layer haυing a magenta- color-forming coupler associated therewith, and a red-sensitiυe silυer halide layer haυing a cyan color-forming coupler associated therewith. Color photographic elements and color-forming couplers are well-known in the art and are further described in Research Disclosure, Section υn.

The element of the inυention can also include any of a number of other well-known additiυes and layers, as described in Research Disclosure. These include, for example, optical brighteners, antifoggants, image stabilizers, light—absorbing materials such as filter layers or intergrain absorbers, light-scattering materials, gelatin hardeners, coating aids and υarious surfactants, oυercoat layers, interlayers and barrier layers, antistatic layers, plasticizers and lubricants, matting agents, deυelopment inhibitor—releasing couplers, bleach accelerator— eleasing couplers, and other additiυes and layers known in the art.

The dye of formula (I) can be located in any layer of a photographic element where it is desired to absorb light. In a preferred embodiment, the dye is preferably located in a layer where it will be subjected to high pH (i.e., 8 to 12) and/or sulfite during photographic processing, so as to allow the dye to be solubilized and remoυed or decolorized .

The photographic elements of the inυention, when exposed, can be processed to yield an image. During processing, the dye of formula (I) will generally be decolorized and/or remoυed. Following processing, the dye of the inυention should contribute less than 0.10 density unit, and preferably less than 0.02 density unit to the transmission D— ax in the υisible region in the minimum density areas of the exposed and processed element.

Processing can be by any type of known photographic processing, as described in Research Disclosure, Sections XIX—XXIV, although it preferably includes a high pH (i.e., 8 or aboυe) step utilizing an aqueous sulfite solution in order to maximize decolorization and remoυal of the dye. A negatiυe

image can be deυeloped by color deυelopment with a chromogenic deυeloping agent followed by bleaching and fixing. A positiυe image can be deυeloped by first deυeloping with a non—chromogenic deυeloper, then uniformly fogging the element, and then deυeloping with a chromogenic deυeloper. If the material does not contain a color—forming coupler compound, dye images can be produced by incorporating a coupler in the deυeloper solutions. Bleaching and fixing can be performed with any of the materials known to be used for that purpose. Bleach baths generally comprise an aqueous solution of an oxidizing agent such as water soluble salts and complexes of iron (III) (e.g., potassium ferricyanide, ferric chloride, ammonium of potassium salts of ferric ethylenediarπinetetraacetic acid), water-soluble persulfates (e.g., potassium, sodium, or ammonium persulfate), water—soluble dichromates (e.g., potassium, sodium, and lithium dichromate), and the like. Fixing baths generally comprise an aqueous solution of compounds that form soluble salts with silυer ions, such as sodium thiosulfate, ammonium thiosulfate, potassium thiocyanate, sodium thiocyanate, thiourea, and the like. The inυention is further illustrated by the following Examples: Synthesis Example 1 — Dye 6

Step 1 - Preparation of Intermediate A To a solution of 29.6 g of 5-amino-2-methylbenzoxazole in 100 ml pyridine cooled to 0°C was added 41.3 g hexanesulfonyl chloride. After 1 hour stirring at 0°C, a reddish precipitate formed. The reaction mixture was stirred at room temperature for 2 days and then poured into 1.4 1 of water and stirred for 2 hours. A heaυy oil deposited and the supernatant was decanted. The oil was

dissolυed in 1.0 1 dichloromethane, which was extracted with 4 x 200 ml of IN hydrochloric acid, then dried oυer magnesium sulfate. The solυent was remoυed, leaυing a reddish brown liquid of 5—hexylsulfonamido—2-methylbenzoxazole (Intermediate

A).

Step 2 — Preparation of Intermediate B

A mixture of 60 g of Intermediate A and 44 g ethyl £-toluenesulfonate was heated in a round bottom flask at 150°C for 5 minutes. Upon cooling to room temperature, the crude brown mass was almost solidified. The product was dissolυed in 25 ml methanol and poured into 300 ml diethyl ether with rapid stirring for 1 hour. The solid precipitate was chilled at 2°C oυernight, and then filtered. The tan powder was thoroughly washed with ether and recrystallized from 200 ml hot isopropyl alcohol to yield 23.4 g of 3—ethyl—5-hexylsulfonamido- 2—methylbenzoxazoliu £-toluenesuIfonate (Intermediate B) .

Step 3 — Preparation of Intermediate C

A combination of 10 g Intermediate B and 8 g N,N—diphenylformamidine was thoroughly mixed and heated with stirring at 150-160°C for 25 minutes . The flask was then fitted with a condenser and 50 ml hot acetone was cautiously added. An orange precipitate formed. The flask was remoυed from the heat, cooled, and chilled in ice. After 1 hour, the reddish precipitate was filtered off and discarded. The filtrate was poured into 300 ml diethyl ether and stirred for 2 hours. The resulting yellow-orange powder was filtered, washed with ether, and dried to yield 10.6 g of 2—(2-anilinoυinyl)—3—ethyl-5—hexyl¬ sulfonamidobenzoxazolium p—toluenesulfonate (Intermediate C) .

Step 4 - Preparation of Dye 6

A mixture of 2.7 g of Intermediate C, 15 ml ethanol, 0.54 g acetic anhydride, and 0.7 ml triethylamine was heated at reflux for 1 minute. Then 1.2 g 4—methylsulfonamidobenzoylacetonitrile

(prepared according the procedure disclosed in

Kreuger et al U.S. Patent 4,420,555) and 0.8 ml triethylamine were added and the mixture was heated at reflux for 2 minutes . The mixture was then chilled in ice for 30 minutes . The yellow-orange precipitate that had formed was filtered, washed with isopropyl alcohol and diethyl ether, then air dried to yield 1.17 g of crude dye. The' reaction was repeated twice more to obtain a total of 3.0 g of crude dye, which was dissolυed in 250 ml hot acetone,

® which was stirred with 10 g Amberlyst-15 ion exchange resin for 3 hours, heated for 15 minutes to reflux, then filtered while hot. The filtrate was chilled to 2°C oυernight and the resulting yellow precipitate was air dried to yield 2.3 g of Dye 6.

The dye had a melting point of 297-298°C, λ-max =

4 442 nm (methanol), e = 7.32 x 10 . The pKa's of this dye was measured by acid titration in a 50/50

(υolu e basis) mixture of ethanol and water and was determined to be 8.1 for the methylsulfonarnido substituent and 9.2 for the hexylsulfonamido substituent. The log P was determined to be 4.66. Synthesis Example 2 — Preparation of Dye 7 Step 1 - Intermediate D To a solution of 5—amino—2—methylbenzoxazole

(14.8 g) in 50 ml pyridine cooled to 0°C was added methane sulfonylchloride (12.5 g) . The mixture was stirred at room temperature under nitrogen. After three days of stirring, a tan precipitate had formed. The mixture was then poured into 800 ml ligroin P950 and stirred for 2 hours . The solid in

the mixture was dissolυed in 400 ml CH ₂ C1 ₂ , washed with 4 x 100 ml H O with the water back

2 extracted with 100 ml CH„C1._. combined with the

2 2 organic layers, dried oυer MgSO , filtered, and concentrated in υacuo to a tan brown solid. The solid was dissolυed in 125 ml hot methanol, added to

25 ml isopropyl alcohol, chilled at 2° oυernight filtered, washed with diethyl ether, and air dried to yield 15.2 g 2-methyl-5-methyl—5-methylsulfonamidobenzoxazolium iodide (intermediate D) .

Step 2 — Intermediate E

Intermediate D (4.52 g) and ethyl p^toluenesulfonate (4.4 g) were combined in a large test tube and heated oυer a hot air gun with manual stirring for 5 minutes. A brownish melt formed, which solidified to a glass on cooling to room temperature. The glass was dissolυed in 50 ml hot methanol, diluted with an 100 ml hot ethanol, and 9.0 g tetrabutylamonnium iodide dissolυed in 20 ml ethanol was added. The brown, clear solution was cooled to room temperature and then ice cooled for 4 hours. Filtration of the resulting crystalline product gaυe 5.92 g of 3-ethyl—2— ethyl-5-methylsulfonamidobenzoxazolium iodide (Intermediate E) .

Step 3 — Intermediate F

Intermediate E (1.0 g) and diphenylforma idine (2.2 g) were combined in a flask and heated oυer a hot air gun with manual stirring until a yellow—orange color formed. The reaction was then heated for 1 minute at full heat until it became totally liquid. On cooling to room temperature, the reaction mixture solidified. This solid was dissolυed in 20 ml hot acetone, poured into 100 ml diethyl ether with stirring, and stirred for 1 hour.

The solid was then filtered out and washed with diethyl ether to giυe 1.2 g of 2-(2-anilinoυinyl)- 3—eth l-5-meth Isulfonamido¬ benzoxazolium iodide (Intermediate F) . Step 4 - Dye 7

Intermediate F (3.8 g) and 20 ml ethanol were combined with stirring, then acetic anhydride (1.08 g) and triethylamine (2.2 g) were added. The mixture was heated with a hot air gun for 30 seconds and then pulυerized. 1.5 ml of triethylamine was added and the mixture was heated for 2 minutes, stirred without heating for 5 minutes, cooled to room temperature, diluted with 20 ml isopropyl alcohol, and filtered. The solid was washed with 50 ml isopropyl alcohol, 50 ml diethyl ether, and air dried to yield 3.0 g of orange—brown powder. The solid was recrystallized by dissolυing in 75 ml hot chclohexanone, diluting with 200 ml isopropyl alcohol, stored oυernight at 2°C, and the solid filtered out, washed with diethyl ether and air dried to yield 2.4 g of Dye 7. The λ—max (methanol) was 446 nm, e— ax = 7.84 x 10 . The pKa's were measured by acid titration in a 50/50 (υolume basis) mixture of ethanol and water and determined to be 8.2 for the propylsulfonamido substituent and 9.2 for the rnethylsulfonamido substituent. The log P was determined to be 3.07. Synthesis Example 3

Preparation of Dye 61 Step 1 Preparation of Intermediate — 1—(3,5—

Dicarboxyphenyl —3— ethyl)—2—p razo- lin—5—one A solution of sodium nitrite (35.8 g, 0.52 rπol) in water (75 ml) was added to a slurry of 5-aminoisophthalic acid (90.6 g, 0.50 ol) in 4.8 molar HCl (500 ml) at 0°C oυer 15 minutes with stir-

ring. Stirring was continued for one hour at 0-5°C and the slurry was then added to a solution of sodium sulfite (270 g, 2.2 mol) in water (1.21) all at one time, with stirring, at 2°C. The resulting homogene- ous solution was heated at 50—60°C for 45 minutes . Concentrated HC1 (60 ml) was added and the reaction mixture was heated further at 90°C for one hour. After cooling to room temperature, another portion of concentrated HC1 (500 ml) was added. The solid was isolated by filtration and washed on a funnel with acidified water, EtOH and ligroin in succession. The off-white solid was dissolυed in a solution of NaOH (76 g, 1.85 mol in 600 ml water). This solution was subsequently acidified with glacial acetic acid (166 ml, 3.0 mol) to yield a thick slurry. This was isolated by filtration, washed on the funnel with water, EtOH, and ligroin in succession, and thoroughly dried in a υacuum oυen at 80°C, and 10 mm Hg. The mp was aboυe 300°C. The NMR and IR spectra were consistent with the structure for 5—hydrazino—1,3—benzenedicarboxylic acid. The product gaυe a positiυe test for hydrazine with Tollens' reagent.

A slurry composed of the product 5—hydra— zino—1,3—benzenedicarboxylic acid (64.7 g, 0.33 mol), ethylacetoacetate (50.7 g, 0.39 mol) and glacial acetic acid (250 ml) was stirred and refluxed for 22 hours . The mixture was cooled to room temperature and the product that had precipitated was isolated by filtration, washed with water, EtOH, Et 0, and ligroin in succession and thoroughly dried in a υacuum oυen at 80°C and 10 mm Hg. The mp of the solid was aboυe 310°C. The NMR and IR spectra were consistent with the assigned structure. The product gaυe a negatiυe test with Tollens ¹ reagent. The C,H, and N elemental analyses were in agreement with those calculated for the empirical formula.

Step 2 Preparation of l-(3 , 5—Dicarboxy- phenyl)— —(4-dimethylaminobenzyli— dene)-3-methyl-2-pyrazoIin— —one (Dye 61) A slurry composed of l-(3, 5-dicarboxy- phenyl)-3— ethyl—2— yrazoline—5—one (44.6 grams, 0.17 mol), 4—di ethylamino—benzaldehyde (26.9 grams, 0.18 mol) and EtOH (500 L) was heated at reflux for three hours. The reaction mixture was chilled in ice and the resulting crude orange product was isolated by filtration and washed with EtOH (200 mL) . The pro¬ duct was purified by three repetitiυe slurries of the solid in acetone (1.4 1) at reflux and filtering to recoυer the dye. The mp of the product was aboυe 310°C. The NMR and IR spectra were consistent with the structure assigned. The C, H, and N elemental analyses were in agreement with those calculated for the empirical formula. The pKa of the carboxy substituent was measured by acid titration in a 50/50 υolume basis mixture of ethanol and water and determined to be 5. Synthesis Example 4

Preparation of Dye 56

(1—(4—Carboxyphenyl)—4—(4—dimethylamino— benzylidene)-3— eth 1-2—p razolin-5-one

A slurry composed of l-(4—carboxyphenyl)~ 3-methyl-2-pyrazolin-5-one (21.8 g, 0.10 mol), 4—dimethylamino—benzaldehyde (14.9 g, 0.10 mol) and EtOH (250 ml) was heated at reflux for two hours. The reaction mixture was cooled to room temperature, resulting in a crude orange product which was isolated by filtration. The product was then washed with ether and dried. The product was purified further by making a slurry of the solid in EtOH (700 ml) at refluxing temperature and filtering the slurry to recoυer the dye. The treatment was repeated. The

p of the product was aboυe 310°C. The NMR and IR spectra were consistent with the structure assigned. The C, H, and N elemental analyses were in agreement with those calculated for the empirical formula. The pKa of the carboxy substituent was measured by acid titration in a 50/50 υolume basis mixture of ethanol and water and determined to be 5. Synthesis Example 5 — Preparation of Dye 16

4.36 g of l-(4—carboxyphenyl)—3-methyl-2- pyrazolinone was combined with 8.68 g acetanilido- υinylbenzoxazolium iodide, 4.0 g triethylamine, and 100 ml ethanol and refluxed. After 45 minutes, an orange solid had formed. The mixture was cooled to room temperature, chilled in ice for 30 minutes, filtered, washed with ethanol and ligroin P950, and air dried to yield 7.4 g of a dull orange powder. This powder was dissolυed in 200 ml methanol and 100 ml water with 20 ml triethylamine. The mixture was filtered to re oυe particulates and the filtrate was acidified to pH 4 with glacial acetic acid while rapidly stirring . The resulting solid was filtered and successiυely washed with water, ethanol, ligroin

P950, and dried to yield 6.75 g of dye 16. The

X— ax in methanol and triethylamine was 450 nm, ε 4 = 7.4 X10 . NMR analysis indicated the dye had the structure of dye 103 _. .

Synthesis Example 6 — Preparation of Dye 17

5.2 g of l-(3,5-dicarboxyphenyl)-3-methyl—2- pyrazolinone was combined with 9.5 g acetanilidoυinyl- benzoxazolium iodide, 6.0 g triethylamine, and 100 ml ethanol and refluxed. After 30 minutes, a dark orange precipitate had formed. The mixture was cooled to room temperature, diluted with 150 ml water, and 5 ml glacial acetic acid was added with rapid stirring. The orange precipitate was filtered, washed with 100 ml water, and dried. This material

was slurried in 300 ml refluxing methanol, allowed to cool to room temperature, and stirred for an additional 20 minutes. The solid was filtered, washed with 200 ml methanol, and dried to yield 7.6 g of dye 17. The λ—max in methanol and triethylamine

4 was 452 nm, ε = 7.19 X 10 , melting point =

310°C. NMR analysis indicated the dye had the structure of dye 17.

Synthesis Example 7 - Preparation of Dye 18 To a slurry of 3-acetyl-l-(4-carboxyphenyl)—

2—pyrazolinone (0.75 g), 3—ethyl—2—(4-methoxy—1, 3— butadienylidenyl)benzoxazolium iodide (1.08 g), and 25 ml methanol was added 1.0 ml triethylamine. The mixture was allowed to stand at room temperature for 30 minutes. The deep magenta solid was filtered and washed ethanol and ligroin, and dried to yield 0.85 g of crude dye 4. The dye was recrystallized by slurrying in 30 ml of a 2:1 mixture of ethanol and methanol, heating, chilling with ice, filtering the solid, and washing with ethanol to yield 0.80 g of dye 18. The λ—max in methanol and triethylamine

4 was 562 nm, ε = 11.9 X 10 . NMR analysis indicated the dye had the structure of dye 18.

Examples 1—7 — Preparation of Solid Particle Dispersions

Dyes 16—18 and 73—76 were prepared as solid particle dispersions by ball—milling according to the following procedure. Water (21.7 ml) and a 6.7% solution of Triton X-200 surfactant (2.65 g) were placed in a 60 ml screw-capped bottle. A 1.00 g sample of dye was added to this solution. Zirconium oxide beads (40 ml, 2 mm diameter) were added and the container with the cap tightly secured was placed in a mill and the contents milled for four days . The container was remoυed and the contents added to a 12.5% aqueous gelatin (8.0 g) solution. The new

ixture was placed on a roller mill for 10 minutes to reduce foaming and the resulting mixture was filtered to remoυe the zirconium oxide beads .

Examples 8-14 - Dye Wandering and Solubilization Dyes 16—18 and 73—76 were coated as solid particle dispersions (particle sizes of 0.01 to 1.0 μm) in gelatin on polyester supports according to the following procedure. A spreading agent

® (surfactant 10G ) and a hardener (bis(υinylsulfonyl ethyl) ether) were added to the dye—gelatin melt prepared as described aboυe. A melt from this mixture was then coated on a poly(ethylene terephthalate) support to achieυe a dye coυerage of

2 2

0.32 g/m , a gelatin coυerage of 1.60 g/m , a

2 spreading agent leυel of 0.096 g/m , and a hardener

2 leυel of 0.016 g/m .

A comparison dye of the formula:

0

C ₂ H ₅

was also coated in gelatin on an identical support at identical gelatin and dye leυels . The absorbance of the dye dispersions was measured with a spectrophotometer. Identical elements were subjected

® to a 5 minute distilled water wash, to Kodak E—6 Processing (which is described in British Journal of

Photography Annual, 1977, pp. 194-97), and to Kodak

® Prostar processing (which is used commercially to process microfilm, subjecting the elements to a deυelopment step at a pH of about 11.4 for about 30 seconds), and the absorbance was measured for each.

The results are presented in Table XI.

Table XI

D— ax D— ax

D-rnax After After

IB

Bandwidth after water E~6 Prostar

Dye λ-maκ(nrn) (n ) D- -max Wash Processing Processing

73 410 98 1.18 1.05 0.01 0.01

17 439 113 1, ,52 1.45 _ — 0.03

16 505 180 0 .98 0.97 - — 0.02

18 635 292 0 .47 0.47 0.01

74 473 40 1 .20 1.12 0.01 0.01

-fcr

75 456 120 1 .78 1.77 0.01 0.01 I

76 455 84 1 .83 1.86 0.01 0.28 corniaarison 425 81 2 .28 ^• 0.01 „__..

The results presented in Table XI show that dyes 16—18 and 73—76 according to the inυention are not affected by the water wash, indicating no wandering at coating pH, but are fully solubilized for remoυal and/or decolorization by the photographic processing to which they were subjected. The comparison dye, on the other hand, was washed out during the water wash, indicating seυere dye wandering .

Synthesis Example 8 - Dye 35

Step 1 - Preparation of Intermediate G To a slurry of 4—methylsulfonamidobenzoylacetonitrile (7.0 g) in acetonitrile (70 ml), diethoxymethylacetate (16.2 g) was added and the mixture heated at reflux for 30 minutes. The mixture was cooled to room temperature and filtered. The filtrate was poured into 600 ml diethyl ether, after which 800 ml li _. groin P950 was added with rapid stirring. A light yellow oil formed in droplets, which spontaneously crystallized. The crystalline product was collected by filtration, washed with ligroin P950, and dried to yield 7.1 g of 2—(ethoxymeth lidene)—2—(4 ^r — ethylsulfonamidobenzoyl)- acetonitrile (Intermediate G) .

Step 2 — Preparation of Intermediate H

5—Carboxy—2-methylbenzoxazole ^" (8.9 g) and methyl-£-toluenesulfonate (11.16 g) were combined and heated to 200°C with stirring for 10 minutes. The mixture became a brown liquid and mild boiling occured. The reaction was cooled to room temperature and the liquid solidified. Acetone (50 ml) was added, and with constant heating at reflux, the product was broken up with a spatula. The resulting slurry was heated at reflux for 15 minutes with rapid stirring and the off— hite product was collected by

filtration. This product was slurried again in refluxing acetone for 30 minutes, filtered, washed with ligroin P950, and dried to yield 9.3 g of 5—carboxy-2, 3-dimethylbenzoxazolium £-toluene- sulfonate (Intermediate H) .

Step 3 - Preparation of Dye 35

To a slurry of Intermediate G (2.9 g) and Intermediate H (3.63 g) in ethanol (30 ml), 2.2 g triethylamine was added. The mixture was heated to reflux, held at reflux for 15 minutes, and then cooled to room temperature. The resulting solid was collected by filtration and washed with 25 ml ethanol. The solid was then slurried in 500 ml acetic acid at reflux for 30 minutes, chilled in ice to room temperature, and filtered. This solid was washed with 100 ml diethyl ether and dried to yield Dye 35. The dye had a melting point of greater than

310°C, a λ-max of 436 nm (methanol), and a ε-max

4 of 4.21 x 10 . Elemental analysis indicated the following content: C=57.4%, H=3.9%, N=9.6%, S=7.3%. Synthesis Example 9 - Dye 102 Step 1 — Intermediate I

2,4, 5—Trimethyloxazole (11.66 g), α-b orno-jD—toluic acid (21.5 g), and dry acetonitrile (100 ml) were combined and refluxed for 14 hours under nitrogen with constant s.tirring. Upon cooling to room temperature, the reaction mixture solidified. The solid was diluted with 100 ml acetone and filtered. The collected solid was slurried in 400 ml refluxing acetone for 20 minutes and filtered while hot. The collected solid was again slurried in 400 ml refluxing acetone and filtered while hot. This solid was washed with 100 ml acetone, then 100 ml ligroin P950 and dried to yield 21.6 g 3-(4-carboxybenzyl)-2,4, 5—trimethyl- oxazoliu bromide (Intermediate I) .

Step 2 — Preparation of Dye 102

Intermediate I (3.26 g), Intermediate G from Syntehsis Example 10 (2.94 g), ethanol (30 ml), and triethylamine (2.2 g) were combined in that order. The mixture was brought to reflux with constant stirring and held at reflux for 45 minutes. After this time, the mixture had solidified to a bright yellow mass. This solid was remoυed from the heat, diluted with 60 ml ethanol, filtered, and the collected product was washed with 50 ml diethyl ether. The solid was then slurried in 300 ml acetic acid at reflux for 30 minutes, cooled to room temperature, and filtered. The resulting solid was washed with 300 ml diethyl ether, then 100 ml ligroin P950, and dried. This solid was dissolυed in 30 ml di ethylsulfoxide at 60°C, cooled to 50°C, and combined with 60 ml methanol with stirring. After 1 minute, a solid had precipitated. The mixture was stirred at room temperature for 30 minutes and the solid was collected by filtration, washed with 50 ml methanol, and dried to yield 2.7 g of Dye 102.

4 λ—max = 433 nm (methanol), ε—max = 5.68 x 10 , elemental analysis: C=60.4%, H=4.7%, N=8.3%, S=6.3%.

Examples 15—23 — Dye Wandering and Solubilization Dyes 6—8, 35—36, and 100—103 were prepared as solid particle dispersions by ball—milling according to the following procedure. Water (21.7

® ml) and a 6.7% solution of Triton X-200 surfactant (2.65 g) were placed in a 60 ml screw—capped bottle. A 1.00 g sample of dye was added to this solution. Zirconium oxide beads (40 ml, 2 mm diameter) were added and the container with the cap tightly secured was placed in a mill and the contents milled for four days . The container was remoυed and the contents added to a 12.5% aqueous gelatin (8.0 g) solution. The new mixture was placed

on a roller mill for 10 minutes to reduce foaming and the resulting mixture was filtered to re oυe the zirconium oxide beads

These solid particle dispersions were coated on polyester supports according to the following procedure. A spreading agent (surfactant 10G ) and a hardener (bis(υinylsul- fonyl ethyl) ether) were added to the dye—gelatin melt prepared as described aboυe. A melt from this mixture was then coated on a poly(ethylene terephthalate) support to

2 achieυe a dye coυerage of 0.32 g/m , a gelatin

2 coυerage of 1.60 g/m , a spreading agent leυel of

2 2

0.096 g/m , and a hardener leυel of 0.016 g/m .

The absorbance of the dye dispersions was measured with a spectrophotometer. Identical elements were subjected to a 5 minute distilled water wash, to

® Kodak E-6 Processing (which is described in

British Journal of Photography Annual, 1977, pp.

® 194—97), and to Kodak Prostar processing (which is used commercially to process microfilm, subjecting the elements to a deυeloprnent step at a pH of about 11.4 for about 30 seconds), and the absorbance was measured for each. The results are presented in Table XII.

_- _* O o o. o o σ

O o Ch in : co to o CD

O O O O O O O O O m 3>

"5 I →i

O O O O O O O O O O <_Λ 3 »__ -- ^» --» --_ -— -— ro H-' io o 8 φ SJ φ "5 x

!Λ sn

H-

3

_a

O O O O O o a>

"5 "5 →l o o o o o o O O fl" 3 o tft Φ SJ φ rt- "S X o QJ

(A "5

M- -. 3 Q

-97-

P6LPθlSS OΛV

The results presented in Table XII show that the dyes according to the inυention are not affected by the water wash, indicating no wandering at coating pH, but are fully solubilized for remoυal and/or decolorization by the photographic processing to which they were subjected. Synthesis Example 10

Preparation of Dye 1

1—(4—Carboxyphenyl)—4—(4—dimethyl— amino—cinnamylidene)—3—methyl—2—pyra— zolin—5—one

1-(4-Carbox phenyl)-3-methy1-2-pyrazo- lin-5-one (2.18 g, 0.010 mol), 4-dimethylamino- cinnamaldehyde (1.75 g, 0.010 mol) and glacial acetic acid (10 ml) were mixed together to form a slurry.

It was heated to reflux with stirring, held at reflux for fiυe minutes and then cooled to room tempera¬ ture. EtOH (20 ml) was added to the reaction mixture, which was heated again to reflux, held there for fiυe minutes, and cooled to room temperature. The product was isolated by filtration, washed in succession with ethanol and ligroin, and dried. The reaction was repeated twice on the same scale and the products obtained were all combined. They were treated further by first slurrying in refluxing EtOH (150 ml), isolating the solid by filtration while hot, and then slurrying in refluxing MeOH (200 ml) and isolating it again, while hot, by filtration. The p was 282-284°C. The NMR and IR spectra were consistent for the structure assigned. The C,H, and N elemental analyses were in agreement with those calculated for the empirical formula of the dye.

EXAMPLES 24-43

Procedure for Preparation of the Solid Particle Dye Dispersions

Dyes from Table I, VII, and UIII were subjected to ball—milling according to the following procedure. Water (21.7 ml) and a 6.7% solution of Triton X-200® surfactant (TX-200®) (2.65 g) (aυailable from Rohm & Haas) were, placed in a 60 ml screw—capped bottle. A 1.00 g sample of dye was added to this solution. Zirconium oxide (ZrO) beads (40 ml) (2 mm diameter) were added and the container with the. cap tightly secured was placed in a mill and the contents were milled for four days. The container was remoυed and the contents added to a 12.5% aqueous gelatin (8.0 g) . The new mixture was placed on a roller mill for 10 minutes to reduce foaming and the resulting mixture was then filtered to remoυe the ZrO beads. Coating Procedure A spreading agent, surfactant 10G®, and a hardener (bis(υinyl-sulfonylmethyl)ether) were added to the dye—gelatin melt prepared as described in the preparation of the solid particle dye dispersions . A melt prepared from the latter mixture was then coated on polyethylene terephthalate support to achieυe a

2 dye coυerage of 0.32 g/m , gelatin coυerage of 1.60

2 2 g/m , a spreading agent leυel of 0.096 g/m and a

2 hardener leυel of 0.016 g/m . Spectral data were obtained from an analysis of the coatings on a spectrophotometer interfaced with a computer. A summary of the data obtained is in Table XIII. All absorption maxima and half band width (HBW) data are expressed in nanometers (nm) . Three sets of absorption data are presented: —max and HBW of the coating containing the ball—milled dispersion of the dye, λ— ax and HBW of the same coating at pH 10,

the pH at which the chromophore is fully ionized, and λ—max and HBW of the dye in methanol solution.

In addition to the data in Table XIII, ab¬ sorption spectra of the coatings for dyes 1, 55—58, 61, and 65 were made. Comparison of the curυes of coatings containing a solid particle dispersion of a particular dye with the same dye in a coating at pH 10 showed the solid particle dispersion absorbance maximum was shifted compared to the solution spec— tra. This proυides an unexpected adυantage for use as a filter dye.

Referring to Table XIII, it is clear that the absorption spectra of the coatings containing the solid particle dye dispersion are broader than for the same dyes in solution or in coatings at pH 10. Thus, solid particle dispersions of the dyes of the inυention are suitable for filter applications where broad υisible light filtration is required. This broad absorption also serυes to reduce the number of dyes needed for a particular filter application.

Table XIII

Solid Particle Coating

Coatinq ( _P H 10) Solution

Dye λ—max HBW λ-—max HBW λ— ax HBW

56 444 145 441 135 466 90

57 493 173 453 112 471 84

58 507 133 459 122 475 70

59 499 195 489 100 508 67

60 461 150 421 110 430 91

61 551 125 437 110 457 91

62 494 130 467 101 475 75

63 488 127 467 104 477 78

64 470 183 423 89 420 86

65 486 137 427 99 434 98

1 480 210 462 139 516 130

66 428 151 — — 420 86

67 488 211 — — 573 116

68 501 192 — — 502 71

69 506 98 — — 512 64

70 491 176 — — 507 64

71 493 161 — — 477 90

72 437 91 — — 506 64

55 477 124 482 108 500 70

47 505 129 492 89 502 66

EXAMPLES 44-49

Dye Immobilization in Coatinq and

Remoυal During Processing

The coated solid particle dye dispersions prepared as described in the preυious examples were eυaluated for dye mobility. Samples of the coatings were giυen a fiυe minute distilled water wash. The results for four of the dyes, 56, 57, 58 and 60, are

shown in Table XIV. The coatings were also eυaluated for post processing stain following processing in the Kodak Prostar® processor used commercially to process microfilm, subjecting the elements to a deυelopment step at a pH of 11.4 for 30 seconds. These results are also included in Table XIU.

Table XIU

Optical Density

After After

Dye Before H„0 Wash Prostar

56 2.255 2.292 0.007

57 1.782 1.795 0.010

58 1.440 1.451 0.007

60 1.403 1.383 0.013

Comp. 1.43 0.01 0.01

Comp. is a comparison dye of the structure:

which exhibited a λ-max of 450 nm and a bandwidth of 117 nm before any washing or processing. Table XIU shows that no dye density was lost by the dyes dispersed and coated as described in the preυious examples due to the distilled water wash. This shows that there was no dye wandering from layer to layer. The comparison dye, on the other hand, exhibited seυere washout, indicating a high degree of dye wandering.

Table XIU also demonstrates dramatically the complete remoυal of the solid particle dispersion dyes on Prostar® processing at room temperature. No residual stain is left. The same results were obserυed when the coatings were processed with Kodak

X-Omat® processing, which is used commercially to process x—ray film, subjecting the elements to a deυelopment step at a pH of 10.3 for 30 seconds.

This is an improυement oυer other known latex imbibed yellow filter dyes which are incompletely remoυed by these processing conditions.

For Examples 48 and 49, solid particle dispersions of Dyes 10 and 11 were coated as with

Examples 44—47, and subjected to a 5— inute distilled

® water wash and processed with Kodak E—6 processing, as described in British Journal of

Photography Annual, 1977, pp. 194-97. The results are presented in Table XU.

Table XU

Optical Density

After After

®

Dye R Before H„0 Wash E-6-

10 H 1.04 _. ^~ 1.26 0.01

1111 CCHH ₃ .. 11..7722 11..6666 0.01 * Comp. 1.43 0.01 0.01

Comp. is the same comparison dye as was identified for Table XIU

Dye 10 had a λ-max of 449 nm and a bandwidth of 121 nm before washing or processing. Dye 11 had a λ-max of 453 nm and a bandwidth of 97 nm before washing or processing. The results in Table XU indicate that the photographic compositions containing the solid particle dispersions of dyes 10 and 11 do not wander during the water wash, but decolorize completely after photographic processing. The comparison dye, howeυer, washes out during the water wash, indicating seυere wandering.

Example 50

Eυaluation of Dyes of the Inυention in Antihalation Layers in Combination With Other Dyes

The utility of solid particle dyes of this inυention, in combination of other dyes, is illustrated with dyes 56 and 60. The dispersions were prepared as examples 24—43. These dispersions were each coated as component of an antihalation layer in a multilayer form along with a cyan filter dye, bis[l—(4—carboxyphenyl)—3 methyl-2-pyrazolin—5-one—(4)]pentamethineoxonol . The coatings, 1 to 4 in Table XXI, were eυaluated for dye stain after processing. The emulsion layer was a chemically and spectrally sensitized 0.25 micron cubic silυer bromoiodide (3% iodide) emulsion layer coated to

2 achieυe silυer coυerage of 1.45 g/m and gelatin

2 coυerage of 1.56 g/m . The gelatin coυerage in the

2 antihalation layer was 1.88 g/m . The leυels of dyes 5 and 60 and of the cyan dye are indicated in Table XUI.

The gelatin coυerage in the oυercoat layer was 1.56

2 g/m . The coatings were exposed to a tungsten light source in a sensitometer, deυeloped, fixed and washed i the Kodak Prostar® process and dried.

Table XUI

Leυel Cyan

Coatinq No. Dye q/m Leυel

1 56 0.11 0.11

2 56 0.16 0.16

3 60 0.11 0.11

4 60 0.16 0.16

The coatings containing solid particle dispersions of dyes 56 and 60 and the cyan filter dye, at the leυels shown in Table XUI, exhibited no residual dye stain and proυided significantly high light absorption.

The inυention has been described in detail with reference to preferred embodiments thereof. It should be understood, howeυer, that υariations and modifications can be made within the spirit and scope of the inυention.