United States Patent rm. Cl. G03c1/40 US. Cl. 96-100 Claims ABSTRACT OF THE DISCLOSURE The light sensitive silver halide color photographic material comprises finely divided liquid particles containing at least one coupler which is capable of coupling with the oxidation product of a primary aromatic amine type developing agent, and at least one compound which is a solvent for the coupler. The coupler has the general formula:

wherein X is a coupler residue of the phenolic, pyrazolone or acetanilide type, R, is hydrogen or lower alkyl, R and R are individually hydrogen or alkyl (C to C R is hydrogen, or alkyl or alkoxy having 4-18 carbon atoms and n is 0 to 3. When R is hydrogen, R and R are alkyl groups and the total sum of the carbon atoms of R and R is 6 to 25. When R is alkyl or alkoxy, R and R are both hydrogen. The solvent has the general formula:

Y-OO C-jiH-(CHzh-OQ-R,

wherein Y is hydrogen or alkyl (C, to C and R R R R and n are as defined above. Coupler dispersions having improved stability are obtained.

The present invention relates to a light-sensitive color photographic material. More particularly, the invention pertains to a light-sensitive color photographic material to which has been incorporated a novel combination of a coupler with a coupler solvent.

There has already been well known a color photographic process using a coupler having an active methylene group or a phenolic hydroxyl group which, when subjected to color development, couples with an oxidation product of a primary aromatic amine type developing agent. As one of the typical processes for incorporating the coupler into any one of the layers (e.g. emulsion layer, inter layer, etc.) of a light-sensitive color photo graphic material, there is a process in which the coupler is dissolved in a water-immiscible high boiling organic solvent, e.g. dibutyl phthalate or tricresyl phosphate, which can dissolve the said coupler and dyes formed therefrom, and then the resulting solution is emulsified to form a dispersion.

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When the said process is adopted, however, a certain coupler occasionally tends to crystallize of agglomerate in the step of forming the coupler into a dispersion or of coating the dispersion onto a support or in subsequent steps, or during storage of the resuling light-sensitive color photographic material, with the result that the photographic properties of the light-sensitive material are greatly deteriorated.

In order to overcome the above-mentioned drawbacks, various processes have been attempted heretofore. In any of these processes, however, the coupler cannot sufliciently be prevented from crystallization, or the reactivity of the coupler with a color developer is deteriorated even when the crystallization thereof has been alleviated.

The object of the present invention is to provide a lightsensitive color photographic material having excellent photographic properties which is entirely free from such drawbacks as mentioned above. We have found that the above object can be accomplished by using, as a component of a solvent for a coupler of the general Formula I, a compound of the general Formula II.

General Formula I:

X-NHC O?H-(CH2)|1OQRJ General Formula II: l Y-O o Q-GH-toHQFOQ-R,

{h 1i: R:

wherein X is a coupler residue;

Y is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms;

R, is a hydrogen atom or a lower alkyl group;

R and R are individually a hydrogen atom or an alkyl group having 1 to 18 carbon atoms;

R is a hydrogen atom or an alkyl or alkoxy group having 4 to 18 carbon atoms; and

n is an integer of 0 to 3,

provided that in case R is a hydrogen atom, R and R are alkyl groups and the total sum of the carbon atoms of R and R is 6 to 25, and in case R is an alkyl or alkoxy group, both R and R are hydrogen atoms.

When at least one coupler of the general Formula I is incorporated into a coupler solvent containing as a component at least one compound of the general Formula II and the resulting combination is applied to a light-sensitive color photographic material, the coupler can attain such prominent photographic properties that it is greatly prevented from crystallization and agglomeration and has excellent developability without any detrimental elfect on photographic emulsions and on dye images formed after development treatment. The couplers used in the present invention, which are represented by the general Formula I, are preferably those which contain groups having carbon atoms within the aforesaid ranges, in order to prevent the diffusion thereof from layers, to which the couplers have been incorporated, to other layers. Further, the coupler residue should be one capable of forming a dye by coupling with an oxidation product of a p-phenylenediamine type color developing agent. Typical examples of the couplers used in the present invention are as follows:

nnoo-wmu-oQ CH: CHa-l-C O-CH-C ONE- 1 Q has) H2C-CNHCO(OH2)aO- H10 i l 0-6 N 0:5 s 31 1511mm) NHOO (2110 I I 12115 01 CH8 C1 C1 O= MEHMD) \N/ 15 510 I $1 01 CH3 As solvents for the above-mentioned couplers, the compounds of the aforesaid general Formula H may be used either singly or in admixture of 2 or more, or in combination with known coupler solvents, e.g. water-immiscible m high boiling organic solvents such as dibutyl phthalate,

mo-ooo-zn-o-Q n 2 b-onnztm The amount of the compound represented by the general Formula II is ordinarily 0.02 to 3.0 parts per part of the coupler. However, the amount is not always limited to said range, and favorable results can be obtained by any combination of at least one coupler of the general Formula I with at least one compound of the general Formula II.

In the present invention, a mixture of the coupler with the coupler solvent is dispersed in the form of finely divided liquid particles in a water-soluble or -permeable material such as gelatine, polyvinyl alcohol or other watersoluble synthetic resin, or in a light-sensitive silver halide emulsion containing said material as a binder. The coupler is first dissolved in the coupler solvent and then dispersed by way of a homogenizer or the like, the dispersion being stabilized, if necessary, with an emulsifier such as alkylbenzenesulfonate. Alternatively, the dispersion may be formed by dissolving the coupler and the coupler solvent in a low boiling organic solvent such as ethyl acetate and then dispersing the resulting solution in water or in a binder solution. At a later stage, the low boiling organic solvent may be removed, if necessary, by evaporation or washing. The dispersion is coated according to an ordinary procedure on a suitable support, followed by drying, whereby a light-sensitive color photographic material of the present invention can be obtained.

The silver halide emulsion to be used in the present invention may be any of silver bromide, silver iodobromide, silver chloride, silver chlorobromide and the like silver halide emulsions, and the said emulsion and the aforesaid binder may have been incorporated with various photographic additives such as fog inhibitors, stabilizers, sensitizers, hardeners and the like.

In case the coupler is to be added to a silver halide emulsion, the amount thereof is preferably in the range of 1 to 300 g. per mole of the silver halide, and in case the coupler is to be added to other layer of a photographic material, the amount thereof is preferably in the range of 1 to 500 g. per g. of the binder, though the amount is variable depending on the purpose of application of the resulting photographic material.

The present invention is illustrated in detail below with reference to examples, but the invention is not limited only to these examples and various modifications are possible within the scope of the invention.

EXAMPLE 1 3 g. of 1-(2',4,6-trichlorophenyl)-3-[3"-(2"',4"-ditert amylphenoxyacetamide) benzamideJ-S-pyrazolone was dissolved in a mixture of 0.6 g. of 2,4-di-tert-amylphenoxyacetic acid, 0.9 g. of tricresyl phosphate and 9.0 g. of ethyl acetate by heating at 60 C. The resulting solution was poured into a mixture of 23 cc. of a 10% aqueous gelatine solution, 7 cc. of a 5% aqueous sodium dodecylbenzenesulfonate solution and 16 cc. of water, and the resulting mixture was emulsified by passing several times through a homogenizer to obtain a dispersion. This dispersion was heated with stirring on a water bath, and air was blown onto the surface of the dispersion to remove the ethyl acetate from the dispersion completely.

For comparison, a dispersion was prepared in the same manner as above, except that the 2,4-di-tert-amylphenoxyacetic acid was not used and the amount of the tricresyl phosphate was increased by 0.6 g.

The above-mentioned two dispersions were stored in a refrigerator and subjected to stability test to obtain the results shown in the following table:

Ratio of solvent to coupler 1 Turbidity was measured using 0.2 mm. cell in a turbidimeter, Model SEP-PL, manufactured by Nippon Seimitsu Kogaku K.K.

From the above table, it is obviously understood that the dispersion was improved in stability by adding 2,4ditert-amylphenoxyacetic acid to the coupler dispersion.

EXAMPLE 2 5 g. of m-{3-[a-(2,4-di-tert-amylphenoxy) butylamide] benzoyl}-u- (4 nitrophenoxy) -2-methoxy-acetanilide was dissolved at about C. in a mixture comprising 2.5 g. of ethyl-a-(2,4-di-tert-amylphenoxy) propionate and 2.5 g. of dibutyl phthalate. The resulting solution was poured into a mixture of cc. of a 10% aqueous gelatine solution and 10 cc. of a 10% aqueous sodium triisopropylnaphthalenesulfonate solution, and the resulting mixture was emulsified by passing several times through a homogenizer to obtain a dispersion. This dispersion was added to 100 cc. of a silver halide gelatine emulsion, which was then coated according to an ordinary procedure on a sup port, followed by setting and drying, to prepare a sample.

For comparison, a control sample was prepared in the same manner as above, except that the ethyl-a-(2,4-ditert-amylphenoxy) propionate was not used and the amount of the dibutyl phthalate was increased by 2.5 g.

After exposure, the thus prepared 2 samples were individually treated with a developer containing N-ethyl- N-fl-sulfonamidoethyl-3-methyl-4-aminoaniline and then subjected to ordinary after-treatment. The gamma value and maximum density of each sample were as shown in the following table:

Ratio of coupler to solvent As is clear from the above table, the addition of ethyla-(2,4-di-tert-amylphenoxy) propionate to the coupler dispersion increased the contrast and maximum density of the resulting images.

EXAMPLE 3 1.4 g. of 1-(2,4'-dimethyl-6'-chlorophenyl)-3-['y-(3"- n-pentadecylphenoxy)-butylamide]--pyrazolone and 0.6 g. of 1-(2',4'-dimethyl-6'-ch1orophenyl)-3-['y-(3"-n-pentadecylphenoxy)-butylamide] 4 (4"' methoxyphenylazo)-5-pyrazolone were dissolved at about 60 C. in a mixture comprising 0.6 g. of ethyl-'y-(3-n-pentadecylphenoxy) butylate, 1.4 g. of tricresyl phosphate and 6.0 g. of ethyl acetate. The resulting solution was poured into a mixture of 17 cc. of a aqueous gelatine solution, 5 cc. of a 5% aqueous sodium dodecylbenzenesulfonate solution and 12 cc. of water, and the resulting mixture was emulsified by passing several times through a homogenizer to obtain a dispersion. This dispersion was added to 100 cc. of a silver halide gelatine emulsion, which was then coated according to an ordinary procedure on a support, followed by setting and drying, to prepare a sample.

For comparison, a control sample was prepared in the same manner as above, except that the ethyl-'y-(3-n-pentadecylphenoxy) butylate was not used and the amount of the tricresyl phosphate was increased by 0.6 g.

The thus prepared 2 samples were individually treated with a fixing solution containing sodium thiosulfate to remove the silver halide, and then water-washed and dried. The transparency of each sample was as shown in the following table:

Turbidity of fixed sample, percent 1 Control sample 33.5 Sample of the present invention 17.2

1 Turbidity was directly measured according to black board method using a turbidimeter, Model SEP-PL, manufactured by Nippon Seimltsu Kogaku K.K.

From the above table, it is understood that the sample was greatly improved in transparency by adding ethyl-'y- (3-n-pentadecylphenoxy) butylate to the coupler dispersion.

What we claim is:

1. A light-sensitive silver halide color photographic material which comprises finely divided liquid particles containing at least one coupler being capable of coupling with the oxidation product of a primary aromatic amine type developing agent and having the general Formula I: X-NHCO-(FH-(CHzh-OQ-Ri I l: I ia (I) wherein X is a coupler residue of the phenolic, pyrazolone or acetanilide type; R is a hydrogen atom or a lower alkyl group; R and R are individually a hydrogen atom or an alkyl group having 1 to 18 carbon atoms; R is a hydrogen atom or an alkyl or alkoxy group having 4 to 18 carbon atoms; and n is an integer of 0 to 3, provided that in case R is a hydrogen atom, R and R are alkyl groups and the total sum of the carbon atoms of R and R is 6 to 25, and in case R is an alkyl or alkoxy group, both R and R are hydrogen atoms, and at least one compound 10 being a solvent for said coupler and having the general Formula II:

Br I

wherein Y is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and R R R R and n are as defined above.

2. A light-sensitive silver halide color photographic material, comprising finely-divided liquid particles containing the coupler 1-(2',4',6'-trchlorophenyl)-3-[3"-(2,4"'-ditert-amyl phenoxy acetoamido)-benzamido]-5-pyrazolone and 2,4-di-tert-amy1 phenoxy acetic acid as a solvent therefor.

3. A light-sensitive silver halide color photographic emulsion which comprises finely divided liquid particles containing at least one coupler being capable of coupling with the oxidation product of a primary aromatic amine type developing agent and having the general Formula I:

wherein X is a coupler residue of the phenolic, pyrazolone or acetanilide type; R is a hydrogen atom or a lower alkyl group; R and R are individually a hydrogen atom or an alkyl group having 1 to 18 carbon atoms; R is a hydrogen atom or an alkyl or alkoxy group having 4 to 18 carbon atoms; and n is an integer of 0 to 3, provided that in case R is a hydrogen atom, R and R are alkyl groups and the total sum of the carbon atoms of R and R is 6 to 25, and in case R is an alkyl or alkoxy group, both R and R are hydrogen atoms, and at least one compound being a solvent for said coupler and having the general Formula II:

OCH;

@ NH.. H C.

m m w W H I 2 m m w 1 CHN/ H. N C N 1 H 1 NHNIOIO NI m H C o .1 n 1 H C d H a 5 w w w x w w M. m 1 w H m 1 "r m N I0 I 1 m m 1 C N a n3 0 N 0 I C O h 1 1 J (JOOCzH5 OCH;

CH: CHr-(k-CO-CHn-C ON I! if