Polymeric competing couplers and their use in photographic silver halide colour materials
United States Patent 3912513
Polymers derived from 4-alkyl-2-pyrazolin-5-ones with an ethylenic acylamino group in the 3-position are described for use in silver halide colour photography as competing couplers having high coupling activity.
US Patent References:
Substituted amidopyrazalones containing a terminal ethylenically unsaturated group
Firestine et al. - December 1967 - 3356686
Color formers
Dawson - February 1968 - 3370952
COLOR TURBIDITY AGENT IN COLOR PHOTOGRAPHIC MATERIALS
Kondo et al. - June 1969 - 3449123
Substituted amidopyrazalones containing a terminal ethylenically unsaturated group
Firestine et al. - December 1967 - 3356686
Color formers
Dawson - February 1968 - 3370952
COLOR TURBIDITY AGENT IN COLOR PHOTOGRAPHIC MATERIALS
Kondo et al. - June 1969 - 3449123
Inventors:
Monbaliu, Marcel Jacob (Mortsel, BE)
Benoy, Gaston Jacob (Edegem, BE)
Van Poucke, Raphael Karel (Berchem, BE)
Sauerteig, Wolfgang (Leverkusen, DT)
Stieler, Dieter (Grobenzell, DT)
De Cat, Arthur Henri (Mortsel, BE)
Benoy, Gaston Jacob (Edegem, BE)
Van Poucke, Raphael Karel (Berchem, BE)
Sauerteig, Wolfgang (Leverkusen, DT)
Stieler, Dieter (Grobenzell, DT)
De Cat, Arthur Henri (Mortsel, BE)
Application Number:
05/432533
Publication Date:
10/14/1975
Filing Date:
01/11/1974
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Export Citation:
Assignee:
Agfa-Gevaert N.V. (Mortsel, BE)
Primary Class:
Other Classes:
430/384, 430/388, 430/507, 430/386, 430/565
International Classes:
C08F20/60; G03C7/327; C08F20/00; G03C1/40; G03C7/00
Field of Search:
96/74,100,56,56.5,114
Primary Examiner:
Brown, Travis J.
Attorney, Agent or Firm:
Breiner A. W.
Claims:
We claim
1. A photographic colour element comprising in a lightsensitive silver halide emulsion layer or in a non-lightsensitive hydrophilic colloid layer in water-permeable relationship with the said emulsion layer a polymeric compound comprising recurring units of the formula: ##EQU3## wherein: R1 represents an alkyl group or an aryl group,
2. Photographic element according to claim 1, wherein R1 is a phenyl group and R2 is methyl.
3. Photographic element according to claim 1, wherein the said polymeric compound is a homopolymer.
4. Photographic element according to claim 1, wherein the said polymeric compound is a copolymer comprising recurring units derived from one or more monomeric compounds containing an ethylenic group and being incapable of oxidative coupling with an aromatic primary amino compound.
5. Photographic element according to claim 1, wherein the said polymeric compound is a copolymer comprising recurring units derived from one or more monomeric compounds selected from the group consisting of acrylic acid, methacrylic acid, esters and amides of these acrylic acids, styrene, vinyl toluene and divinyl benzene.
6. A photographic element according to claim 1, comprising at least one blue-sensitive silver halide emulsion layer containing a colour coupler for yellow, at least one green-sensitized silver halide emulsion layer containing a colour coupler for magenta, at least one red-sensitized silver halide emulsion layer containing a colour coupler for cyan and one or more intermediate or filter layers wherein the said intermediate and/or filter layers comprise the said polymeric compound.
7. Process for the production of a photographic colour image by development of a photographic element containing image-wise exposed silver halide with the aid of a developing agent which by reduction of the exposed silver halide is converted in its oxidized form and as such forms a dye image by coupling with one or more colour forming coupler compounds wherein colour reproduction is improved by coupling of undesirable oxidation products of developing agent with a polymeric compound as defined in claim 1.
8. Process for the production of a photographic colour image by development of a photographic element containing image-wise exposed silver halide with the aid of a developing agent which by reduction of the exposed silver halide is converted in its oxidized form and as such forms a dye image by coupling with one or more colour forming coupler compounds wherein colour reproduction is improved by coupling of undesirable oxidation products of developing agent with a polymeric compound as defined in claim 2.
1. A photographic colour element comprising in a lightsensitive silver halide emulsion layer or in a non-lightsensitive hydrophilic colloid layer in water-permeable relationship with the said emulsion layer a polymeric compound comprising recurring units of the formula: ##EQU3## wherein: R1 represents an alkyl group or an aryl group,
2. Photographic element according to claim 1, wherein R1 is a phenyl group and R2 is methyl.
3. Photographic element according to claim 1, wherein the said polymeric compound is a homopolymer.
4. Photographic element according to claim 1, wherein the said polymeric compound is a copolymer comprising recurring units derived from one or more monomeric compounds containing an ethylenic group and being incapable of oxidative coupling with an aromatic primary amino compound.
5. Photographic element according to claim 1, wherein the said polymeric compound is a copolymer comprising recurring units derived from one or more monomeric compounds selected from the group consisting of acrylic acid, methacrylic acid, esters and amides of these acrylic acids, styrene, vinyl toluene and divinyl benzene.
6. A photographic element according to claim 1, comprising at least one blue-sensitive silver halide emulsion layer containing a colour coupler for yellow, at least one green-sensitized silver halide emulsion layer containing a colour coupler for magenta, at least one red-sensitized silver halide emulsion layer containing a colour coupler for cyan and one or more intermediate or filter layers wherein the said intermediate and/or filter layers comprise the said polymeric compound.
7. Process for the production of a photographic colour image by development of a photographic element containing image-wise exposed silver halide with the aid of a developing agent which by reduction of the exposed silver halide is converted in its oxidized form and as such forms a dye image by coupling with one or more colour forming coupler compounds wherein colour reproduction is improved by coupling of undesirable oxidation products of developing agent with a polymeric compound as defined in claim 1.
8. Process for the production of a photographic colour image by development of a photographic element containing image-wise exposed silver halide with the aid of a developing agent which by reduction of the exposed silver halide is converted in its oxidized form and as such forms a dye image by coupling with one or more colour forming coupler compounds wherein colour reproduction is improved by coupling of undesirable oxidation products of developing agent with a polymeric compound as defined in claim 2.
Description:
The present invention relates to novel polymeric compounds and to their use in photographic colour elements as competing couplers for improving the image quality.
It is known e.g. from United Kingdom Pat. Specification No. 861,138 filed Sept. 17, 1967 by Agfa AG, to improve the colour reproduction in photographic colour elements by incorporating therein so-called competing couplers which react with the oxidation products of the developing agent to form colourless compounds. They are used in those instances where undesirable oxidation products of the developing agent should be rendered ineffective so that degradation of the image quality is inhibited. In general, these competing couplers should have high coupling activity.
In the above United Kingdom Patent Specification and in United Kingdom Pat. Specification No. 914,145 filed Oct. 28, 1960 by Agfa AG, it has been proposed to use as competing couplers e.g. 2-pyrazoline-5-one compounds comprising in the coupling position an alkyl group which may be substituted. However, the pyrazolinone competing couplers described in these patents have relatively low coupling activity so that they do not react sufficiently with the undesirable developer oxidation products.
2-PYRAZOLINE-5-ONE COMPETING COUPLERS OF BETTER COUPLING ACTIVITY HAVE BEEN DESCRIBED IN THE PUBLISHED German Pat. Application No. 1,909,067 filed Feb. 24, 1969 by Gevaert-Agfa N.V. but increased coupling activity is still desirable.
In accordance with the present invention novel polymerisable monomeric 2-pyrazoline-5-one compounds are provided carrying in the 4-position an alkyl group which may be substituted. From these monomers, polymeric competing couplers can be formed having a high coupling activity. Moreover, these monomeric 2-pyrazolin-5-one compounds are easily polymerisable, so that polymers can be formed comprising a high content of active substance which is favourable for the formation of very thin intermediate hydrophilic colloid layers comprising the polymeric competing couplers. Polymerisation proceeds better with these monomeric competing couplers than with the corresponding monomeric colour couplers having no substituent in the 4-position.
The monomeric 2-pyrazolin-5-one compounds according to the present invention can be represented by the formula: ##EQU1## wherein: R 1 represents a substituent of the type well known in the 1-position of 2-pyrazolin-5-one colour couplers e.g. alkyl, especially C 1 -C 5 -alkyl, which may be substituted e.g. by fluoro such as 2-trifluoroethyl, cyano such as cyanoethyl and aryl such as benzyl and substituted benzyl, or preferably aryl e.g. phenyl which may be substituted e.g. phenyl substituted by alkyl such as methyl, halogen such as chlorine and bromine, sulpho, alkoxy such as methoxy, alkylsulphonyl such as methylsulphonyl, alkylthio such as methylthio, haloalkyloxy, haloalkylthio, haloalkylsulphonyl, etc.
R 2 represents a C 1 -C 5 alkyl group including a substituted C 1 -C 5 alkyl group e.g. benzyl, R 2 being preferably methyl, and
R 3 represents hydrogen, C 1 -C 4 alkyl e.g. methyl or chlorine.
The polymeric competing couplers according to the present invention comprise recurring units of the formula: ##EQU2## wherein: R 1 , R 2 and R 3 have the same significances given above, and are derived from the above monomeric 2-pyrazolin-5-one compunds by homopolymerization or by copolymerization of the monomeric 2-pyrazolin-5-one compounds with one or more monomers that are not capable of oxidative coupling with aromatic primary amino compounds and that contain at least one ethylenic group, for example acrylic acid, α-chloro acrylic acid, α-alkacrylic acid e.g. methacrylic acid, the esters and amides preferably lower alkyl esters and amides derived from these acrylic acids e.g. acrylamide, methacrylamide, t-butylacrylamide, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate, vinyl esters such as vinyl acetate, vinyl propionate, and vinyl laurate, acrylonitrile, methacrylonitrile, aromatic vinyl compounds, such as stryrene and its derivatives e.g. vinyl toluene, divinyl benzene, vinyl acetophenone, and sulphostyrene, itaconic acid, citraconic acid, crotonic acid, vinylidene chloride, vinyl alkyl ethers, such as vinyl ethyl ether, maleic acid esters, N-vinyl-2-pyrrolidone, N-vinylpyridine, 2- and 4-vinylpyridine, etc. Two or more of the above comonomeric compounds can be used together e.g. n-butyl acrylate and divinylbenzene, styrene and methacrylic acid, n-butylacrylate and methacrylic acid, etc.
As is known in the art of polymeric colour couplers, the ethylenically unsaturated monomers for being copolymerized with the monomeric 2-pyrazolin-5-one compounds corresponding to the above general formula can be chosen so that the physical and/or chemical properties of the resulting copolymer e.g. its solubility, its compatibility with the binder of the photographic colloid composition e.g. gelatin, its flexiblity, its thermal stability etc., are favourable influenced.
Whereas polymeric colour couplers form dyestuffs that should have favourable spectral properties and high stability so that the substituents on the colour coupler units should be selected to meet these requirements, the polymeric competing couplers of the invention form colourless compounds so that the substituents on the competing coupler units are of minor importance in so far as they do not impair the coupling activity to a noteworthy extent.
The monomeric 2-pyrazolin-5-one competing couplers corresponding to the above general formula can be prepared by allowing to react an acid halide of acrylic acid or an α-substituted acrylic acid such as acryloyl and methacryloyl chloride with the appropriate 3-amino-2-pyrazolin-5-one compound. The acylation can be effected in the presence of a Lewis acid as described in U.S. Pat. No. 3,325,482. The 3-amino-2-pyrazolin-5-one compounds can be prepared by cyclisation of the appropriate N-substituted aliphatic or aromatic hydrazine e.g. of the type described in U.S. Pat. No. 2,376,380 of Henry D. Porter and Arnold Weissberger, issued May 22, 1945 and United Kingdom Pat. Nos. 1,069,533 filed July 24, 1964, 1,166,035 filed Sept. 26, 1966, 1,190,914 filed Sept. 26, 1966 and 1,269,355 filed July 18, 1968 all by Gevaert-Agfa N.V., with the ethyl ester of an α-alkyl-β-amino-β-ethoxy-propionic acid.
The polymeric competing couplers according to the present invention are preferably prepared by emulsion polymerisation techniques according to which latices are obtained which can be used as such for incorporating the polymeric competing couplers into light-sensitive materials. Interesting emulsion polymerisation techniques are for instance described in Belgian Pat. Specification No. 669,971 filed Sept. 22, 1965 by du Pont de Nemours, according to which latices are formed of polymeric colour couplers by emulsion polymerisation in aqueous gelatin, and in United Kingdom Pat. No. 1,130,581 filed June 23, 1964 by Gevaert Photo-Production N.V. according to which latices are formed of polymeric colour couplers by emulsion polymerisation in water.
The processes can be applied to the formation of homopolymers and to the formation of co-polymers. In the latter case the comonomer may be a liquid co-monomer and may in some cases serve as solvent for the normally solid monomer.
These and other data including e.g. examples of polymerisation initiators, emulsifying agents and suitable solvents as well as instructions relating to the formation of the initial emulsions and/or suspensions are set forth in the aforementioned United Kingdom Patent No. 1,130,581.
Amongst the polymerisation initiators suitable for use in the above emulsion polymerisation process may be mentioned: persulphates such as ammonium and potassium persulphate, azonitrile compounds such as 4,4'-azo-bis(4-cyanovaleric acid) as well as peroxide compounds such as benzoyl peroxide, hydrogen peroxide.
As is described in the above United Kingdom Patent Specification surface active compounds of various classes and known per se are available for use as emulsifying agents, amongst others soaps, sulphonates and sulphates, cationic and amphoteric compounds and high molecular weight protective colloids.
The latices obtained generally comprise between about 2 and about 50 % by weight of polymeric competing coupler in respect of the total amount of latex.
The polymeric competing couplers according to the present invention can be characterized by their so-called equivalent molecular weight. By equivalent molecular weight is understood the number of grams of polymer containing 1 mole of polymerized monomeric competing coupler. It can be compared with the molecular weight of the non-polymeric classical non-migratory competing couplers. The equivalent molecular weight of the polymeric competing couplers according to the invention can vary within very wide limits, preferably from about 250 to 2000.
The following preparations illustrate how the monomeric and polymeric competing couplers of the present invention can be prepared.
A. MONOMERIC COMPOUNDS
Preparation 1
1-phenyl-3-methacryloylamino-4-methyl-2-pyrazolin-5-one
a. A suspension of 251 g (1.2 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride in 500 ml of hexane was neutralized at 0°-5°C against phenolphthaleine by means of a solution of 65 g of sodium methylate in 400 ml of methanol. While introducing nitrogen, 60 ml of acetic acid and 108 g(1 mole) of phenylhydrazine were added at room temperature. The mixture was stirred for 1 hour whereupon 500 ml of 2N sodium hydroxide were added and the mixture was stirred for 15 min. The pH was adjusted to 4 by addition of 2N hydrochloric acid and the precipitate formed was filtered off and dried.
Yield: 163 g (86 %). Melting point: 147°C.
b. 266 g (1.40 mole) of 1-phenyl-3-amino-4-methyl-2-pyrazolin-5-one prepared as described in step a) were dissolved at 25°C in a solution of 374 g (2.80 mole) of anhydrous aluminium chloride in 900 ml of dry acetonitrile and 28 ml of nitrobenzene. Then 149.4 ml (1.54 mole) of methacryloyl chloride were added and the mixture was refluxed for 1 hour. The solution was poured into ice-water and the precipitate formed was filtered off by suction. After recrystallization from acetonitrile, 206 g (57 %) of monomeric compound were obtained.
Melting point: 147°C.
Preparation 2
1-phenyl-3-acryloylamino-4-methyl-2-pyrazolin-5-one
56.7 g (0.3 mole) of 1-phenyl-3-amino-4-methyl-2-pyrazolin-5-one were added to a solution of 89.4 g (0.67 mole) of anhydrous aluminium chloride in 120 ml of dry nitrobenzene in such a way that the temperature was kept under 60°C. The solution formed was cooled to room-temperature and treated for 15 min with 29.8 g (0.33 mole) of acryloylchloride whereby the temperature rose to 40°C. After having stirred the reaction mixture for 3 hours at room temperature the mixture was poured into water. The mixture was left standing overnight and the precipitate formed was filtered off and recrystallized from acetonitrile.
Yield: 18.0 g (25 %). Melting point: 149°C.
Preparation 3
1-p-methylsulphonylphenyl-3-methacryloylamino-4-methyl-2 -pyrazolin-5-one
a. A solution of 251 g (1.2 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride in 500 ml of methanol was cooled to 0°C and neutralized against phenolphthalein by addition of a sodium methylate solution in methanol. While introducing nitrogen, 60 ml of acetic acid and 186 g (1 mole) of p-methylsulphonylphenylhydrazine were added. The solution was stirred for 90 min. at room-temperature whereupon 1 litre of 2N sodium hydroxide was added. After having been stirred for 30 min. at 30°-40°C the solution was neutralized by means of 2N hydrochloric acid. The precipitate was filtered off and dried.
Yield: 240 g (90 %). Melting point: 248°C.
b. 107 g (0.4 mole) of 1-p-methylsulphonylphenyl-3-amino14-methyl-2-pyrazolin-5-one and 42.7 ml (0.44 mole) of methacryloyl chloride were dissolved in a solution of 107 g of anhydrous aluminium chloride in 200 ml of nitrobenzene. The mixture was kept for 1 hour at 40°C whereupon it was poured into icewater with stirring. The crystalline precipitate was filtered off and rerystallized from acetonitrile.
Yield: 50 g (53 %). Melting point: 179°C.
Preparation 4
1-(2-chloro-4-methylsulphonylphenyl)-3-methacryloyl-amin o-4-methyl-2-pyrazo lin-5-one
a. A solution of 146 g (0.84 mole) of the ethyl ester of α-methyl-β-ethoxy-β-imino propionic acid hydrochloride in 540 ml of dry methanol was neutralized at 0°C against phenolphthalein by addition of 48 g of sodium methylate dissolved in 200 ml of methanol. Then, 42 ml of acetic acid and 142 g (0.84 mole) of 2-chloro-4-methylsulphonyl-phenyl hydrazine were added. The mixture was stirred for 1 hour at 25°-30°C, and a solution of 78.5 g of sodium methylate in 900 ml of methanol was added. Stirring was continued for 1 hour whereupon the mixture was poured into water and neutralized with 2N hydrochloric acid. The precipitate was filtered off and dried.
Yield 168 g (80 %). Melting point: 240°C.
b. 75.4 g (0.25 mole) of the 2-pyrazolin-5-one compound of step a) and 66.7 g (0.5 mole) of anhydrous aluminium chloride were dissolved in 150 ml of nitrobenzene at 40°-50°C whereupon 28.7 ml (0.275 mole) of methacryloyl chloride were added at room temperature. The mixture was stirred for 4 hours at 25°C and then poured into water. The precipitate was filtered off and boiled with acetonitrile.
Yield: 65 g (70 %). Melting point: 210°C.
Preparation 5
1-(2,4,6-trichlorophenyl)-3-methacryloylamino-4-methyl-2 -pyrazolin-5-one
a. 25.14 g (0.12 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride were dissolved in 60 ml of methanol and neutralized against phenolphthalein by means of a solution of 6.5 g of sodium methylate in 60 ml of methanol. While introducing nitrogen, 6 ml of acetic acid and 21.25 g (0.1 mole) of 2,4,6-trichlorophenyl hydrazine were added and the temperature was raised to 40°C. The mixture was stirred for 2 hours, 11.8 g of sodium methylate in 100 ml of methanol were added; stirring was continued for 1 hour and after filtering the solution was neutralized with 2N hydrochloric acid. The precipitate was filtered off.
Yield: 25 g (85 %). Melting point: 221°C.
b. A solution of 20.2 g (0.15 mole) of aluminium chloride, 2 ml of nitrobenzene, 14.6 g (0.05 mole) of the 2-pyrazolin-5-one compound of step (a), and 5.4 ml of methacryloyl chloride in 100 ml of acetonitrile was refluxed for 1 hour. The mixture was poured into water and the precipitate filtered off was recrystallized from acetonitrile.
Yield: 9.6 g (53 %). Melting point: 130°-132°C.
Preparation 6
1-m-chlorophenyl-3-methacryloylamino-4-methyl-2-pyrazoli n-5-one
a. A solution of 101 g (0.48 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride in 200 ml of dry methanol was neutralized at 0°C against phenolphtalein by means of a solution of sodium methylate in methanol. While introducing nitrogen, 24 ml of acetic acid and 62.7 g (0.44 mole) of m-chlorophenylhydrazine were added so that the temperature rose to 30°C. The mixture was stirred for 30 min. whereupon 400 ml of 2N sodium hydroxide were added. After 30 min., the pH was adjusted to 4 by means of 2N hydrochloric acid. The precipitate formed was filtered off.
Yield: 81 g (90 %). Melting point: 138°C.
b. To a solution of 20 g (0.15 mole) of anhydrous aluminium chloride in 60 ml of nitrobenzene, 22.35 g (0.1 mole) of 1-m-chlorophenyl-3-amino-4-methyl-2-pyrazolin-5-one and 10.7 g (0.11 mole) of methacryloyl chloride were added. The mixture was stirred for 2 hours at 20°C and then poured into ice-water. The nitrobenzene layer was isolated and extracted with 5N sodium hydroxide. The aqueous extract was neutralized and the precipitate filtered off.
Yield: 8 g (31 %). Melting point: 132°C (with decomposition).
B. POLYMERIC COMPOUNDS
Preparation 7
Copolymer of n-butylacrylate and the compound of preparation 1
In a 2 litres reaction vessel fitted with stirrer, nitrogen inlet, thermometer, reflux concenser and dropping funnel were placed: 750 ml of demineralized water, 210 g of 1-phenyl-3-methacryloulamino-4-methyl-2-pyrazolin-5-one, and 1.5 g of sodium oleyl methyl tauride. While introducing nitrogen, the suspension was stirred for 30 min. at room temperature and then heated to 70°C. 30 g of n-butylacrylate were added at once and the temperature was raised to 90°C, whereupon 37.5 ml of a 1 % aqueous solution of the sodium salt of 4,4'-azobis(4-cyanovaleric acid) were added. Polymerisation started after 5 min. and the temperature rose to 96°-97°C. In a period of about 30 min. were added: 60 g of n-butyl acrylate, 135 ml of a 10 % aqueous solution of sodium oleyl methyl tauride and 113 ml of a 1 % aqueous solution of the sodium salt of 4,4' -azo-bis(4-cyanovaleric acid). The mixture was stirred for 30 min. at the boiling temperature whereupon unreacted n-butyl-acrylate was distilled off. The latex obtained was filtered.
Yield: 1400 ml of latex.
Concentration of solids per 100 ml of latex: 19.7 g
Concentration of polymer per 100 ml of latex: 17.4 g
Equivalent molecular weight: 330.
Preparations 8-12
The following polymers were prepared in a similar way as the copolymer of preparation 7 using the monomer of preparation 1 as monomeric competing coupler.
________________________________________________________ __________________ Amount of per 100 ml of monomeric latex Equiv. Prepa- competing Amount of g g mol. ration coupler comonomer(s) solids polymer weight ____________________________________________________________ ______________ 8 40 g 60 g methylacrylate 15.80 14.50 395 9 40 g 50 g n-butylacrylate 18.10 16.90 615 10 g divinylbenzene 10 50 g 25 g styrene 14.00 12.50 628 25 g methacrylic acid 11 50 g 20 g n-butylacrylate 19.60 18.20 563 30 g methacrylic acid 12 100 g -- 5.60 4.80 257 ____________________________________________________________ ______________
Preparation 13
Copolymer of the compound of preparation 3 and n-butylacrylate.
A suspension of 800 ml of demineralized water, 50 ml of a 10 % aqueous solution of the sodium salt of oleyl methyl tauride, and 70 g of 1-p-methylsulphonylphenyl-3-methacryloylamino-4-methyl-2-pyr azolin-5-one was stirred for 30 min. while introducing nitrogen. The suspension was heated to 70°C and 10 g of n-butyl acrylate were added. The temperature was raised to 90°C and 12.5 ml of a 1 % aqueous solution of the sodium salt of 4,4'-azo-bis(4-cyanovaleric acid) were added. Polymerization started after a few minutes and the temperature rose to 95°C. Over a period of 30 minutes were added: 20 g of n-butyl acrylate and 37.5 ml of the above solution of polymerisation initiator. The mixture was refluxed with stirring for 30 min. and the latex formed was concentrated by evaporation. A little precipitate that formed was filtered off.
Yield: 690 ml of latex.
Concentration of solids per 100 ml of latex: 14.6 g.
Concentration of polymer per 100 ml of latex: 13.8 g.
Equivalent molecular weight: 440.
Preparations 14-17
The following polymers were prepared in a similar way as the copolymer of preparation 13 using the monomer of preparation 3 as monomeric competing coupler.
______________________________________ per 100 ml of Amount of latex Equiv. Prepa- monomeric Amount of g g mol. ration comonomer(s) solids polymer wt. ______________________________________ 14 70 g 20 g of n-butyl- 20.8 19.7 464 acrylate 10 g of methacry- lic acid 15 50 g 50 g of t-butyl- 20.7 19.4 663 acrylamide 16 50 g 25 g of styrene 24.4 23.0 650 25 g of methacry- lic acid ______________________________________
The high coupling activity of the polymeric competing couplers of the present invention as compared with nonpolymeric competing couplers is apparent from the following tests.
Test 1
Materials of the following compositions were prepared:
1. a film support,
2. a red-sensitized gelatino silverbromoiodide emulsion layer comprising per sq.m an amount of silver halide equivalent to 3 g of silver nitrate and containing no colour coupler,
3. an intermediate layer of 1.5 g of gelatin per sq.m optionally containing a competing coupler as listed in the table below in an amount of 1 millimole per sq.m (the latices are used in amounts corresponding to 1 millimole per sq.m of polymerized monomeric coupler),
4. a gelatin layer containing per sq.m 3 g of gelatin and 1 millimole of colour coupler for magenta, and
5. a protective gelatin coating.
The material was exposed to red light and processed in a common colour developing bath. The developer oxidation products diffuse inter alia through the intermediate layer to form a magenta dye in layer 4). The density formed is proportional to the amount of diffused developer oxidation products and is reduced by the presence in the intermediate layer of a competing coupler.
The densities obtained in layer 4) with a number of competing couplers are listed in the following table.
Table ______________________________________ Competing coupler Density ______________________________________ -- 0.12 1-(2,4,6-trichlorophenyl)-3-heptadecyl-4-methyl- 2-pyrazolin-5-one 0.10 1-p-sulphophenyl-3-heptadecyl-4-methyl-2-pyra- zolin-5-one 0.08 latex of preparation 7 0.05 latex of preparation 13 0.03 ______________________________________
Test 2
Materials of the following compositions:
1. a film support
2. a gelatino silverbromoiodide emulsion (4 mole % of iodide) comprising per sq.m an amount of silver halide equivalent to 4 g of silver nitrate and containing no colour coupler,
3. a gelatin intermediate layer of 1,2 μm thickness comprising 1 mmole of competing coupler per sq.m.
4. a gelatin layer containing per sq.m 3 g of gelatin and 1 mmole of colour coupler for magenta,
were processed without preliminary exposure according the colour reversal technique by a black-and-white development, overall exposure and colour development.
The densities of magenta dye formed in layer 4 are listed in the following table.
Table ______________________________________ Competing coupler Density ______________________________________ 1-(p-methylsulphonylphenyl)-3-[β-(2'-tetradecyl- 4'-chloro-5'-methylphenoxy)-ethoxycarbonylamino] 4-methyl-2-pyrazolin-5-one 0.28 latex of preparation 13 0.18 ______________________________________
The above results show that the competing couplers of the present invention have higher coupling activity than known competing couplers.
In order to reach with the known competing couplers the same efficiency as with those of the present invention it is necessary either to increase the amount of competing coupler in the intermediate layer and/or to increase the thickness of the intermediate layer.
Depending on the desired effect the competing couplers of the present invention can be used in one or more silver halide emulsion layers or non-light-sensitive hydrophilic colloid layers in water-permeable relationship with the emulsion layers e.g. intermediate layers and surface coatings. In a hydrophilic colloid surface coating they can be used to react with developer oxidation products which are present in the developing composition and thus prevent these oxidation products from reacting with colour coupler in underlying emulsion layers which would cause colour fog and falsification of colour reproduction. In intermediate layers, they can be used to couple with the oxidation products formed during colour development that diffuse from an emulsion layer into an intermediate layer so that these oxidation products are prevented from diffusing in adjacent emulsion layers where they would cause colour fog and falsification of colour reproduction. It is also possible to use the competing couplers in an emulsion layer itself to reduce colour fog or to regulate the gradation which is important for correct colour reproduction. They can also be used in the emulsion layers to reduce graininess e.g. in colour reversal materials.
The polymeric competing couplers of the present invention lend themselves particularly for use in intermediate gelatin layers. As a matter of fact intermediate layers comprising competing couplers should be as thin as possible and it was found that the polymeric competing couplers of the invention have a high percentage of active units so that little gelatin can be used for coating the layer.
Intermediate layers comprising polymeric competing couplers of the present invention are particularly suitable for use in photographic colour materials of the type described in Belgian Pat. No. 776,272 filed Dec. 6, 1971 by Agfa-Gervaert N.V.
The incorporation of the polymeric colour couplers according to the present invention in the form of latices into silver halide emulsions or hydrophilic colloid e.g. gelatin compositions for the formation of intermediate layers offers several advantages. Indeed, the latices may contain a high percentage of polymer and nevertheless still possess a relatively low viscosity so that the viscosity of the hydrophilic colloid coating composition is not influenced. Moreover, by the use of latices there can be dispensed with the use of organic solvents or alkaline solutions as well as with special dispersing techniques as commonly employed for incorporating colour couplers and competing couplers.
The polymeric competing couplers of the present invention may be used in various kinds of photographic colour materials which include negative, positive as well as reversal material. Photographic multilayer colour materials usually comprise a blue-sensitive silver halide emulsion layer with colour coupler for yellow, a green-sensitized silver halide emulsion layer with colour coupler for magenta and a red-sensitized silver halide emulsion layer with colour coupler for cyan. These colour materials may further comprise one or more intermediate layers, filter layers and protective surface layers.
Colour couplers for yellow are usually of the acylacetamide type, expecially the acylacetanilide type for example benzoyl acetanilide colour couplers wherein both aryl groups may be substituted by groups well known in yellow-forming colour couplers e.g. alkyl, alkoxy, halogen, alkylthio, alkylsulphonyl etc. and wherein the active methylene group may carry a substituent conferring to the colour coupler a 2-equivalent character e.g. a halogen atom such as chlorine, an acyloxy group, an alkoxy, aryloxy or heterocycloxy group, an alkylthio, arylthio or heterocyclic thio group, etc. Particularly suitable yellow forming colour couplers can be found in the published German Pat. Application Nos. 2,114,576, 2,114,577 and 2,114,578 all filed Mar. 25, 1971 by Agfa-Gevaert AG, in U.S. Pat. Nos. 3,619,190 of Marcel Hendrik Verbrugghe and Raymond Albert Roosen, issued Nov. 9, 1971, 3,393,040 of Marcel Hendrik Verbrugghe, Arthur Henri De Cat and Valere Frans Danckaert, issued July 16, 1968, 3,393,041 of Marcel Hendrik Verbrugghe, Arthus Henri De Cat and Raymond Albert Roosen, issued July 16, 1968, 3,660,095 of Marcel Hendrik Verbrugghe and Arthur Henri De Cat, issued May 2, 1972 and in Belgian Patent 717,841 filed July 10, 1968 by Gervaert-Agfa N.V.
It is also possible to use combinations of colour forming couplers in a single silver halide emulsion layer e.g. a colour coupler according to the published German Pat. Application No. 2,114,577 mentioned above and a colour coupler according to the Belgian Pat. No. 717,841 mentioned above.
Colour couplers for magenta are usually of the 2-pyrazolin-5-one type carrying in the 1-position an alkyl including substituted alkyl group e.g. haloalkyl such as fluoroalkyl, cyanoalkyl and benzyl, or aryl including substituted aryl e.g. phenyl which may be substituted by alkyl, halogen, alkoxy, haloalkoxy, alkylsulphonyl, haloalkylsulphonyl, alkylthio, haloalkylthio, etc. The active methylene group may also carry a substituent as described above conferring to the colour coupler a 2-equivalent character. Particularly suitable magenta forming colour couplers can be found in U.S. Pat. Nos. 3,325,482 of Marcel Jacob Monbaliu, Arthus Henri De Cat and Raphael Karel Van Poucke, issued June 13, 1967, 3,330839 of Jozef Frans Willems, Albert Lucien Poot and Raymond Albert Roosen, issued July 11, 1967, 3,330,660 of Raphael Karel Van Poucke, Arthur Henri De Cat and Marcel Jacob Monbaliu, issued July 11, 1967, 3,441,414 of Raphael Karel Van Poucke, Arthur Henri De Cat and Marcel Jacob Monbaliu, issued Apr. 29, 1969, 3,462,270 of Hector Alfons Vanden Eynde, Robert Joseph Pollet and Arthur Henri De Cat, issued Aug. 19, 1969, 3,470,191 of Pieter Hendrik Eerdekens and Robert Joseph Pollet, issued Sept. 30, 1969, 3,563,745 of Albert Lucient Poot and Jean Marie Nys, issued Feb. 16, 1971, 3,567,449 of Hector Alfons Vanden Eynde, Robert Joseph Pollet and Arthur Henri De Cat, issued Mar. 2, 1971, 3,615,504 of Marcel Hacob Monbaliu and Raphael Karel Van Poucke, issued Oct. 26, 1971, 3,615,505 of Raphael Karel Van Poucke, Marcel Hacob Monbaliu and Gaston Jacob Benoy, issued Oct. 26, 1971, and 3,623,871 of Raphael Karel van Poucke, Marcel Jacob Monbaliu, Hans Glockner and Ernst Meier, issued Nov. 30, 1971.
2-equivalent or 4-equivalent colour couplers for cyan are usually of the phenol or naphthol type. Particularly suitable are the colour couplers described in French Pat. No. 2,078,920 filed Feb. 22, 1971 by Gevaert-Agfa N.V., in British Pat. No. 1,004,281 filed Feb. 15, 1961 by Gevaert Photo-Producten N.V. and in U.S. Pat. Nos. 3,079,256 of Raphael Karel Van Poucke, Arthur Henri De Cat and Marcel Hendrik Verbrugghe, issued Feb. 26, 1963, 3,226,230 of Raphael Karel Van Poucke, Hector Alfons Vanden Eynde and Arthur Henri De Cat, issued Dec. 28, 1965, and 3,488,193 of Hector Alfons Vanden Eynde and Arthur Henri De Cat, issued Jan. 6, 1970.
The hydrophilic colloid used as the vehicle for the silver halide emulsion layer and the other hydrophilic colloid layers may be, for example, gelatin, colloidal albumin, zein, casein, a cellulose drivative, a synthetic hydrophilic colloid such as polyvinyl alcohol, poly-N-vinyl pyrrolidone, etc., gelatin being preferred. If desired compatible mixtures of two or more of these colloids may be employed.
The silver halide emulsion layer may comprise various silver salts as the sensitive salt such as silver bromide, silver chloride, silver chlorobromide, silver bromoiodide and silver chlorobromoiodide.
The photographic colour elements comprising the polymeric competing couplers of the present invention may comprise as supports paper, glass, cellulose ester film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film and related films of resinous materials.
In the development of the exposed photographic colour materials aromatic primary amino developing agents are used forming dyestuffs with the colour couplers incorporated in the photographic material and colourless compounds with the polymeric competing couplers of the present invention. Suitable developing agents are p-phenylene diamine and derivatives e.g. N,N-diethyl-p-phenylene diamine, N-butyl-N-sulphobutyl-p-phenylene diamine, 2-amino-5-diethylaminotoluene, 4-amino-N-ethyl-N(β-methane sulphonamidoethyl)-m-toluidine, N-hydroxyethyl-N-ethyl-p-phenylene diamine, etc.
The following example illustrates the use of the polymeric competing couplers of the invention in photographic silver halide colour material.
EXAMPLE
A photographic multilayer negative material A was composed as follows:
1. a common film support,
2. two red-sensitized silver halide emulsion layers each containing a colour coupler for cyan and a mask-forming compound, the undermost emulsion layer being of lower speed than the uppermost emulsion layer,
3. an intermediate gelatin layer,
4. two green-sensitized silver halide emulsion layers each containing a colour coupler for magenta and a mask-forming compound, the undermost emulsion layer being of lower speed than the uppermost emulsion layer,
5. a yellow gelatin filter layer,
6. two non-spectrally-sensitized blue-sensitive silver halide emulsion layers each containing a yellow-forming colour coupler, the uppermost emulsion layer having higher speed than the undermost emulsion layer, and
7. a protective gelatin coating.
For comparison purposes a material B was prepared in exactly the same way as material A with the only difference that both the gelatin-intermediate layer and the filter layer comprise per sq.m an amount of polymeric competing coupler according to preparation 13 corresponding to 1 millimole of polymerized monomeric coupler.
Samples of both materials were exposed to a wedge through a blue, green and red filter and subjected to common negative colour processing for the formation of the yellow, magenta and cyan separation images. The developing agent used was 2-amino-5-[N-ethyl-N(β-methylsulphonylamino)ethyl]amino toluene sulphate.
The separation images of material B showed markedly purer colours than those of material A.
It is known e.g. from United Kingdom Pat. Specification No. 861,138 filed Sept. 17, 1967 by Agfa AG, to improve the colour reproduction in photographic colour elements by incorporating therein so-called competing couplers which react with the oxidation products of the developing agent to form colourless compounds. They are used in those instances where undesirable oxidation products of the developing agent should be rendered ineffective so that degradation of the image quality is inhibited. In general, these competing couplers should have high coupling activity.
In the above United Kingdom Patent Specification and in United Kingdom Pat. Specification No. 914,145 filed Oct. 28, 1960 by Agfa AG, it has been proposed to use as competing couplers e.g. 2-pyrazoline-5-one compounds comprising in the coupling position an alkyl group which may be substituted. However, the pyrazolinone competing couplers described in these patents have relatively low coupling activity so that they do not react sufficiently with the undesirable developer oxidation products.
2-PYRAZOLINE-5-ONE COMPETING COUPLERS OF BETTER COUPLING ACTIVITY HAVE BEEN DESCRIBED IN THE PUBLISHED German Pat. Application No. 1,909,067 filed Feb. 24, 1969 by Gevaert-Agfa N.V. but increased coupling activity is still desirable.
In accordance with the present invention novel polymerisable monomeric 2-pyrazoline-5-one compounds are provided carrying in the 4-position an alkyl group which may be substituted. From these monomers, polymeric competing couplers can be formed having a high coupling activity. Moreover, these monomeric 2-pyrazolin-5-one compounds are easily polymerisable, so that polymers can be formed comprising a high content of active substance which is favourable for the formation of very thin intermediate hydrophilic colloid layers comprising the polymeric competing couplers. Polymerisation proceeds better with these monomeric competing couplers than with the corresponding monomeric colour couplers having no substituent in the 4-position.
The monomeric 2-pyrazolin-5-one compounds according to the present invention can be represented by the formula: ##EQU1## wherein: R 1 represents a substituent of the type well known in the 1-position of 2-pyrazolin-5-one colour couplers e.g. alkyl, especially C 1 -C 5 -alkyl, which may be substituted e.g. by fluoro such as 2-trifluoroethyl, cyano such as cyanoethyl and aryl such as benzyl and substituted benzyl, or preferably aryl e.g. phenyl which may be substituted e.g. phenyl substituted by alkyl such as methyl, halogen such as chlorine and bromine, sulpho, alkoxy such as methoxy, alkylsulphonyl such as methylsulphonyl, alkylthio such as methylthio, haloalkyloxy, haloalkylthio, haloalkylsulphonyl, etc.
R 2 represents a C 1 -C 5 alkyl group including a substituted C 1 -C 5 alkyl group e.g. benzyl, R 2 being preferably methyl, and
R 3 represents hydrogen, C 1 -C 4 alkyl e.g. methyl or chlorine.
The polymeric competing couplers according to the present invention comprise recurring units of the formula: ##EQU2## wherein: R 1 , R 2 and R 3 have the same significances given above, and are derived from the above monomeric 2-pyrazolin-5-one compunds by homopolymerization or by copolymerization of the monomeric 2-pyrazolin-5-one compounds with one or more monomers that are not capable of oxidative coupling with aromatic primary amino compounds and that contain at least one ethylenic group, for example acrylic acid, α-chloro acrylic acid, α-alkacrylic acid e.g. methacrylic acid, the esters and amides preferably lower alkyl esters and amides derived from these acrylic acids e.g. acrylamide, methacrylamide, t-butylacrylamide, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate, vinyl esters such as vinyl acetate, vinyl propionate, and vinyl laurate, acrylonitrile, methacrylonitrile, aromatic vinyl compounds, such as stryrene and its derivatives e.g. vinyl toluene, divinyl benzene, vinyl acetophenone, and sulphostyrene, itaconic acid, citraconic acid, crotonic acid, vinylidene chloride, vinyl alkyl ethers, such as vinyl ethyl ether, maleic acid esters, N-vinyl-2-pyrrolidone, N-vinylpyridine, 2- and 4-vinylpyridine, etc. Two or more of the above comonomeric compounds can be used together e.g. n-butyl acrylate and divinylbenzene, styrene and methacrylic acid, n-butylacrylate and methacrylic acid, etc.
As is known in the art of polymeric colour couplers, the ethylenically unsaturated monomers for being copolymerized with the monomeric 2-pyrazolin-5-one compounds corresponding to the above general formula can be chosen so that the physical and/or chemical properties of the resulting copolymer e.g. its solubility, its compatibility with the binder of the photographic colloid composition e.g. gelatin, its flexiblity, its thermal stability etc., are favourable influenced.
Whereas polymeric colour couplers form dyestuffs that should have favourable spectral properties and high stability so that the substituents on the colour coupler units should be selected to meet these requirements, the polymeric competing couplers of the invention form colourless compounds so that the substituents on the competing coupler units are of minor importance in so far as they do not impair the coupling activity to a noteworthy extent.
The monomeric 2-pyrazolin-5-one competing couplers corresponding to the above general formula can be prepared by allowing to react an acid halide of acrylic acid or an α-substituted acrylic acid such as acryloyl and methacryloyl chloride with the appropriate 3-amino-2-pyrazolin-5-one compound. The acylation can be effected in the presence of a Lewis acid as described in U.S. Pat. No. 3,325,482. The 3-amino-2-pyrazolin-5-one compounds can be prepared by cyclisation of the appropriate N-substituted aliphatic or aromatic hydrazine e.g. of the type described in U.S. Pat. No. 2,376,380 of Henry D. Porter and Arnold Weissberger, issued May 22, 1945 and United Kingdom Pat. Nos. 1,069,533 filed July 24, 1964, 1,166,035 filed Sept. 26, 1966, 1,190,914 filed Sept. 26, 1966 and 1,269,355 filed July 18, 1968 all by Gevaert-Agfa N.V., with the ethyl ester of an α-alkyl-β-amino-β-ethoxy-propionic acid.
The polymeric competing couplers according to the present invention are preferably prepared by emulsion polymerisation techniques according to which latices are obtained which can be used as such for incorporating the polymeric competing couplers into light-sensitive materials. Interesting emulsion polymerisation techniques are for instance described in Belgian Pat. Specification No. 669,971 filed Sept. 22, 1965 by du Pont de Nemours, according to which latices are formed of polymeric colour couplers by emulsion polymerisation in aqueous gelatin, and in United Kingdom Pat. No. 1,130,581 filed June 23, 1964 by Gevaert Photo-Production N.V. according to which latices are formed of polymeric colour couplers by emulsion polymerisation in water.
The processes can be applied to the formation of homopolymers and to the formation of co-polymers. In the latter case the comonomer may be a liquid co-monomer and may in some cases serve as solvent for the normally solid monomer.
These and other data including e.g. examples of polymerisation initiators, emulsifying agents and suitable solvents as well as instructions relating to the formation of the initial emulsions and/or suspensions are set forth in the aforementioned United Kingdom Patent No. 1,130,581.
Amongst the polymerisation initiators suitable for use in the above emulsion polymerisation process may be mentioned: persulphates such as ammonium and potassium persulphate, azonitrile compounds such as 4,4'-azo-bis(4-cyanovaleric acid) as well as peroxide compounds such as benzoyl peroxide, hydrogen peroxide.
As is described in the above United Kingdom Patent Specification surface active compounds of various classes and known per se are available for use as emulsifying agents, amongst others soaps, sulphonates and sulphates, cationic and amphoteric compounds and high molecular weight protective colloids.
The latices obtained generally comprise between about 2 and about 50 % by weight of polymeric competing coupler in respect of the total amount of latex.
The polymeric competing couplers according to the present invention can be characterized by their so-called equivalent molecular weight. By equivalent molecular weight is understood the number of grams of polymer containing 1 mole of polymerized monomeric competing coupler. It can be compared with the molecular weight of the non-polymeric classical non-migratory competing couplers. The equivalent molecular weight of the polymeric competing couplers according to the invention can vary within very wide limits, preferably from about 250 to 2000.
The following preparations illustrate how the monomeric and polymeric competing couplers of the present invention can be prepared.
A. MONOMERIC COMPOUNDS
Preparation 1
1-phenyl-3-methacryloylamino-4-methyl-2-pyrazolin-5-one
a. A suspension of 251 g (1.2 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride in 500 ml of hexane was neutralized at 0°-5°C against phenolphthaleine by means of a solution of 65 g of sodium methylate in 400 ml of methanol. While introducing nitrogen, 60 ml of acetic acid and 108 g(1 mole) of phenylhydrazine were added at room temperature. The mixture was stirred for 1 hour whereupon 500 ml of 2N sodium hydroxide were added and the mixture was stirred for 15 min. The pH was adjusted to 4 by addition of 2N hydrochloric acid and the precipitate formed was filtered off and dried.
Yield: 163 g (86 %). Melting point: 147°C.
b. 266 g (1.40 mole) of 1-phenyl-3-amino-4-methyl-2-pyrazolin-5-one prepared as described in step a) were dissolved at 25°C in a solution of 374 g (2.80 mole) of anhydrous aluminium chloride in 900 ml of dry acetonitrile and 28 ml of nitrobenzene. Then 149.4 ml (1.54 mole) of methacryloyl chloride were added and the mixture was refluxed for 1 hour. The solution was poured into ice-water and the precipitate formed was filtered off by suction. After recrystallization from acetonitrile, 206 g (57 %) of monomeric compound were obtained.
Melting point: 147°C.
Preparation 2
1-phenyl-3-acryloylamino-4-methyl-2-pyrazolin-5-one
56.7 g (0.3 mole) of 1-phenyl-3-amino-4-methyl-2-pyrazolin-5-one were added to a solution of 89.4 g (0.67 mole) of anhydrous aluminium chloride in 120 ml of dry nitrobenzene in such a way that the temperature was kept under 60°C. The solution formed was cooled to room-temperature and treated for 15 min with 29.8 g (0.33 mole) of acryloylchloride whereby the temperature rose to 40°C. After having stirred the reaction mixture for 3 hours at room temperature the mixture was poured into water. The mixture was left standing overnight and the precipitate formed was filtered off and recrystallized from acetonitrile.
Yield: 18.0 g (25 %). Melting point: 149°C.
Preparation 3
1-p-methylsulphonylphenyl-3-methacryloylamino-4-methyl-2 -pyrazolin-5-one
a. A solution of 251 g (1.2 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride in 500 ml of methanol was cooled to 0°C and neutralized against phenolphthalein by addition of a sodium methylate solution in methanol. While introducing nitrogen, 60 ml of acetic acid and 186 g (1 mole) of p-methylsulphonylphenylhydrazine were added. The solution was stirred for 90 min. at room-temperature whereupon 1 litre of 2N sodium hydroxide was added. After having been stirred for 30 min. at 30°-40°C the solution was neutralized by means of 2N hydrochloric acid. The precipitate was filtered off and dried.
Yield: 240 g (90 %). Melting point: 248°C.
b. 107 g (0.4 mole) of 1-p-methylsulphonylphenyl-3-amino14-methyl-2-pyrazolin-5-one and 42.7 ml (0.44 mole) of methacryloyl chloride were dissolved in a solution of 107 g of anhydrous aluminium chloride in 200 ml of nitrobenzene. The mixture was kept for 1 hour at 40°C whereupon it was poured into icewater with stirring. The crystalline precipitate was filtered off and rerystallized from acetonitrile.
Yield: 50 g (53 %). Melting point: 179°C.
Preparation 4
1-(2-chloro-4-methylsulphonylphenyl)-3-methacryloyl-amin o-4-methyl-2-pyrazo lin-5-one
a. A solution of 146 g (0.84 mole) of the ethyl ester of α-methyl-β-ethoxy-β-imino propionic acid hydrochloride in 540 ml of dry methanol was neutralized at 0°C against phenolphthalein by addition of 48 g of sodium methylate dissolved in 200 ml of methanol. Then, 42 ml of acetic acid and 142 g (0.84 mole) of 2-chloro-4-methylsulphonyl-phenyl hydrazine were added. The mixture was stirred for 1 hour at 25°-30°C, and a solution of 78.5 g of sodium methylate in 900 ml of methanol was added. Stirring was continued for 1 hour whereupon the mixture was poured into water and neutralized with 2N hydrochloric acid. The precipitate was filtered off and dried.
Yield 168 g (80 %). Melting point: 240°C.
b. 75.4 g (0.25 mole) of the 2-pyrazolin-5-one compound of step a) and 66.7 g (0.5 mole) of anhydrous aluminium chloride were dissolved in 150 ml of nitrobenzene at 40°-50°C whereupon 28.7 ml (0.275 mole) of methacryloyl chloride were added at room temperature. The mixture was stirred for 4 hours at 25°C and then poured into water. The precipitate was filtered off and boiled with acetonitrile.
Yield: 65 g (70 %). Melting point: 210°C.
Preparation 5
1-(2,4,6-trichlorophenyl)-3-methacryloylamino-4-methyl-2 -pyrazolin-5-one
a. 25.14 g (0.12 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride were dissolved in 60 ml of methanol and neutralized against phenolphthalein by means of a solution of 6.5 g of sodium methylate in 60 ml of methanol. While introducing nitrogen, 6 ml of acetic acid and 21.25 g (0.1 mole) of 2,4,6-trichlorophenyl hydrazine were added and the temperature was raised to 40°C. The mixture was stirred for 2 hours, 11.8 g of sodium methylate in 100 ml of methanol were added; stirring was continued for 1 hour and after filtering the solution was neutralized with 2N hydrochloric acid. The precipitate was filtered off.
Yield: 25 g (85 %). Melting point: 221°C.
b. A solution of 20.2 g (0.15 mole) of aluminium chloride, 2 ml of nitrobenzene, 14.6 g (0.05 mole) of the 2-pyrazolin-5-one compound of step (a), and 5.4 ml of methacryloyl chloride in 100 ml of acetonitrile was refluxed for 1 hour. The mixture was poured into water and the precipitate filtered off was recrystallized from acetonitrile.
Yield: 9.6 g (53 %). Melting point: 130°-132°C.
Preparation 6
1-m-chlorophenyl-3-methacryloylamino-4-methyl-2-pyrazoli n-5-one
a. A solution of 101 g (0.48 mole) of the ethyl ester of α-methyl-β-ethoxy-β-iminopropionic acid hydrochloride in 200 ml of dry methanol was neutralized at 0°C against phenolphtalein by means of a solution of sodium methylate in methanol. While introducing nitrogen, 24 ml of acetic acid and 62.7 g (0.44 mole) of m-chlorophenylhydrazine were added so that the temperature rose to 30°C. The mixture was stirred for 30 min. whereupon 400 ml of 2N sodium hydroxide were added. After 30 min., the pH was adjusted to 4 by means of 2N hydrochloric acid. The precipitate formed was filtered off.
Yield: 81 g (90 %). Melting point: 138°C.
b. To a solution of 20 g (0.15 mole) of anhydrous aluminium chloride in 60 ml of nitrobenzene, 22.35 g (0.1 mole) of 1-m-chlorophenyl-3-amino-4-methyl-2-pyrazolin-5-one and 10.7 g (0.11 mole) of methacryloyl chloride were added. The mixture was stirred for 2 hours at 20°C and then poured into ice-water. The nitrobenzene layer was isolated and extracted with 5N sodium hydroxide. The aqueous extract was neutralized and the precipitate filtered off.
Yield: 8 g (31 %). Melting point: 132°C (with decomposition).
B. POLYMERIC COMPOUNDS
Preparation 7
Copolymer of n-butylacrylate and the compound of preparation 1
In a 2 litres reaction vessel fitted with stirrer, nitrogen inlet, thermometer, reflux concenser and dropping funnel were placed: 750 ml of demineralized water, 210 g of 1-phenyl-3-methacryloulamino-4-methyl-2-pyrazolin-5-one, and 1.5 g of sodium oleyl methyl tauride. While introducing nitrogen, the suspension was stirred for 30 min. at room temperature and then heated to 70°C. 30 g of n-butylacrylate were added at once and the temperature was raised to 90°C, whereupon 37.5 ml of a 1 % aqueous solution of the sodium salt of 4,4'-azobis(4-cyanovaleric acid) were added. Polymerisation started after 5 min. and the temperature rose to 96°-97°C. In a period of about 30 min. were added: 60 g of n-butyl acrylate, 135 ml of a 10 % aqueous solution of sodium oleyl methyl tauride and 113 ml of a 1 % aqueous solution of the sodium salt of 4,4' -azo-bis(4-cyanovaleric acid). The mixture was stirred for 30 min. at the boiling temperature whereupon unreacted n-butyl-acrylate was distilled off. The latex obtained was filtered.
Yield: 1400 ml of latex.
Concentration of solids per 100 ml of latex: 19.7 g
Concentration of polymer per 100 ml of latex: 17.4 g
Equivalent molecular weight: 330.
Preparations 8-12
The following polymers were prepared in a similar way as the copolymer of preparation 7 using the monomer of preparation 1 as monomeric competing coupler.
________________________________________________________ __________________ Amount of per 100 ml of monomeric latex Equiv. Prepa- competing Amount of g g mol. ration coupler comonomer(s) solids polymer weight ____________________________________________________________ ______________ 8 40 g 60 g methylacrylate 15.80 14.50 395 9 40 g 50 g n-butylacrylate 18.10 16.90 615 10 g divinylbenzene 10 50 g 25 g styrene 14.00 12.50 628 25 g methacrylic acid 11 50 g 20 g n-butylacrylate 19.60 18.20 563 30 g methacrylic acid 12 100 g -- 5.60 4.80 257 ____________________________________________________________ ______________
Preparation 13
Copolymer of the compound of preparation 3 and n-butylacrylate.
A suspension of 800 ml of demineralized water, 50 ml of a 10 % aqueous solution of the sodium salt of oleyl methyl tauride, and 70 g of 1-p-methylsulphonylphenyl-3-methacryloylamino-4-methyl-2-pyr azolin-5-one was stirred for 30 min. while introducing nitrogen. The suspension was heated to 70°C and 10 g of n-butyl acrylate were added. The temperature was raised to 90°C and 12.5 ml of a 1 % aqueous solution of the sodium salt of 4,4'-azo-bis(4-cyanovaleric acid) were added. Polymerization started after a few minutes and the temperature rose to 95°C. Over a period of 30 minutes were added: 20 g of n-butyl acrylate and 37.5 ml of the above solution of polymerisation initiator. The mixture was refluxed with stirring for 30 min. and the latex formed was concentrated by evaporation. A little precipitate that formed was filtered off.
Yield: 690 ml of latex.
Concentration of solids per 100 ml of latex: 14.6 g.
Concentration of polymer per 100 ml of latex: 13.8 g.
Equivalent molecular weight: 440.
Preparations 14-17
The following polymers were prepared in a similar way as the copolymer of preparation 13 using the monomer of preparation 3 as monomeric competing coupler.
______________________________________ per 100 ml of Amount of latex Equiv. Prepa- monomeric Amount of g g mol. ration comonomer(s) solids polymer wt. ______________________________________ 14 70 g 20 g of n-butyl- 20.8 19.7 464 acrylate 10 g of methacry- lic acid 15 50 g 50 g of t-butyl- 20.7 19.4 663 acrylamide 16 50 g 25 g of styrene 24.4 23.0 650 25 g of methacry- lic acid ______________________________________
The high coupling activity of the polymeric competing couplers of the present invention as compared with nonpolymeric competing couplers is apparent from the following tests.
Test 1
Materials of the following compositions were prepared:
1. a film support,
2. a red-sensitized gelatino silverbromoiodide emulsion layer comprising per sq.m an amount of silver halide equivalent to 3 g of silver nitrate and containing no colour coupler,
3. an intermediate layer of 1.5 g of gelatin per sq.m optionally containing a competing coupler as listed in the table below in an amount of 1 millimole per sq.m (the latices are used in amounts corresponding to 1 millimole per sq.m of polymerized monomeric coupler),
4. a gelatin layer containing per sq.m 3 g of gelatin and 1 millimole of colour coupler for magenta, and
5. a protective gelatin coating.
The material was exposed to red light and processed in a common colour developing bath. The developer oxidation products diffuse inter alia through the intermediate layer to form a magenta dye in layer 4). The density formed is proportional to the amount of diffused developer oxidation products and is reduced by the presence in the intermediate layer of a competing coupler.
The densities obtained in layer 4) with a number of competing couplers are listed in the following table.
Table ______________________________________ Competing coupler Density ______________________________________ -- 0.12 1-(2,4,6-trichlorophenyl)-3-heptadecyl-4-methyl- 2-pyrazolin-5-one 0.10 1-p-sulphophenyl-3-heptadecyl-4-methyl-2-pyra- zolin-5-one 0.08 latex of preparation 7 0.05 latex of preparation 13 0.03 ______________________________________
Test 2
Materials of the following compositions:
1. a film support
2. a gelatino silverbromoiodide emulsion (4 mole % of iodide) comprising per sq.m an amount of silver halide equivalent to 4 g of silver nitrate and containing no colour coupler,
3. a gelatin intermediate layer of 1,2 μm thickness comprising 1 mmole of competing coupler per sq.m.
4. a gelatin layer containing per sq.m 3 g of gelatin and 1 mmole of colour coupler for magenta,
were processed without preliminary exposure according the colour reversal technique by a black-and-white development, overall exposure and colour development.
The densities of magenta dye formed in layer 4 are listed in the following table.
Table ______________________________________ Competing coupler Density ______________________________________ 1-(p-methylsulphonylphenyl)-3-[β-(2'-tetradecyl- 4'-chloro-5'-methylphenoxy)-ethoxycarbonylamino] 4-methyl-2-pyrazolin-5-one 0.28 latex of preparation 13 0.18 ______________________________________
The above results show that the competing couplers of the present invention have higher coupling activity than known competing couplers.
In order to reach with the known competing couplers the same efficiency as with those of the present invention it is necessary either to increase the amount of competing coupler in the intermediate layer and/or to increase the thickness of the intermediate layer.
Depending on the desired effect the competing couplers of the present invention can be used in one or more silver halide emulsion layers or non-light-sensitive hydrophilic colloid layers in water-permeable relationship with the emulsion layers e.g. intermediate layers and surface coatings. In a hydrophilic colloid surface coating they can be used to react with developer oxidation products which are present in the developing composition and thus prevent these oxidation products from reacting with colour coupler in underlying emulsion layers which would cause colour fog and falsification of colour reproduction. In intermediate layers, they can be used to couple with the oxidation products formed during colour development that diffuse from an emulsion layer into an intermediate layer so that these oxidation products are prevented from diffusing in adjacent emulsion layers where they would cause colour fog and falsification of colour reproduction. It is also possible to use the competing couplers in an emulsion layer itself to reduce colour fog or to regulate the gradation which is important for correct colour reproduction. They can also be used in the emulsion layers to reduce graininess e.g. in colour reversal materials.
The polymeric competing couplers of the present invention lend themselves particularly for use in intermediate gelatin layers. As a matter of fact intermediate layers comprising competing couplers should be as thin as possible and it was found that the polymeric competing couplers of the invention have a high percentage of active units so that little gelatin can be used for coating the layer.
Intermediate layers comprising polymeric competing couplers of the present invention are particularly suitable for use in photographic colour materials of the type described in Belgian Pat. No. 776,272 filed Dec. 6, 1971 by Agfa-Gervaert N.V.
The incorporation of the polymeric colour couplers according to the present invention in the form of latices into silver halide emulsions or hydrophilic colloid e.g. gelatin compositions for the formation of intermediate layers offers several advantages. Indeed, the latices may contain a high percentage of polymer and nevertheless still possess a relatively low viscosity so that the viscosity of the hydrophilic colloid coating composition is not influenced. Moreover, by the use of latices there can be dispensed with the use of organic solvents or alkaline solutions as well as with special dispersing techniques as commonly employed for incorporating colour couplers and competing couplers.
The polymeric competing couplers of the present invention may be used in various kinds of photographic colour materials which include negative, positive as well as reversal material. Photographic multilayer colour materials usually comprise a blue-sensitive silver halide emulsion layer with colour coupler for yellow, a green-sensitized silver halide emulsion layer with colour coupler for magenta and a red-sensitized silver halide emulsion layer with colour coupler for cyan. These colour materials may further comprise one or more intermediate layers, filter layers and protective surface layers.
Colour couplers for yellow are usually of the acylacetamide type, expecially the acylacetanilide type for example benzoyl acetanilide colour couplers wherein both aryl groups may be substituted by groups well known in yellow-forming colour couplers e.g. alkyl, alkoxy, halogen, alkylthio, alkylsulphonyl etc. and wherein the active methylene group may carry a substituent conferring to the colour coupler a 2-equivalent character e.g. a halogen atom such as chlorine, an acyloxy group, an alkoxy, aryloxy or heterocycloxy group, an alkylthio, arylthio or heterocyclic thio group, etc. Particularly suitable yellow forming colour couplers can be found in the published German Pat. Application Nos. 2,114,576, 2,114,577 and 2,114,578 all filed Mar. 25, 1971 by Agfa-Gevaert AG, in U.S. Pat. Nos. 3,619,190 of Marcel Hendrik Verbrugghe and Raymond Albert Roosen, issued Nov. 9, 1971, 3,393,040 of Marcel Hendrik Verbrugghe, Arthur Henri De Cat and Valere Frans Danckaert, issued July 16, 1968, 3,393,041 of Marcel Hendrik Verbrugghe, Arthus Henri De Cat and Raymond Albert Roosen, issued July 16, 1968, 3,660,095 of Marcel Hendrik Verbrugghe and Arthur Henri De Cat, issued May 2, 1972 and in Belgian Patent 717,841 filed July 10, 1968 by Gervaert-Agfa N.V.
It is also possible to use combinations of colour forming couplers in a single silver halide emulsion layer e.g. a colour coupler according to the published German Pat. Application No. 2,114,577 mentioned above and a colour coupler according to the Belgian Pat. No. 717,841 mentioned above.
Colour couplers for magenta are usually of the 2-pyrazolin-5-one type carrying in the 1-position an alkyl including substituted alkyl group e.g. haloalkyl such as fluoroalkyl, cyanoalkyl and benzyl, or aryl including substituted aryl e.g. phenyl which may be substituted by alkyl, halogen, alkoxy, haloalkoxy, alkylsulphonyl, haloalkylsulphonyl, alkylthio, haloalkylthio, etc. The active methylene group may also carry a substituent as described above conferring to the colour coupler a 2-equivalent character. Particularly suitable magenta forming colour couplers can be found in U.S. Pat. Nos. 3,325,482 of Marcel Jacob Monbaliu, Arthus Henri De Cat and Raphael Karel Van Poucke, issued June 13, 1967, 3,330839 of Jozef Frans Willems, Albert Lucien Poot and Raymond Albert Roosen, issued July 11, 1967, 3,330,660 of Raphael Karel Van Poucke, Arthur Henri De Cat and Marcel Jacob Monbaliu, issued July 11, 1967, 3,441,414 of Raphael Karel Van Poucke, Arthur Henri De Cat and Marcel Jacob Monbaliu, issued Apr. 29, 1969, 3,462,270 of Hector Alfons Vanden Eynde, Robert Joseph Pollet and Arthur Henri De Cat, issued Aug. 19, 1969, 3,470,191 of Pieter Hendrik Eerdekens and Robert Joseph Pollet, issued Sept. 30, 1969, 3,563,745 of Albert Lucient Poot and Jean Marie Nys, issued Feb. 16, 1971, 3,567,449 of Hector Alfons Vanden Eynde, Robert Joseph Pollet and Arthur Henri De Cat, issued Mar. 2, 1971, 3,615,504 of Marcel Hacob Monbaliu and Raphael Karel Van Poucke, issued Oct. 26, 1971, 3,615,505 of Raphael Karel Van Poucke, Marcel Hacob Monbaliu and Gaston Jacob Benoy, issued Oct. 26, 1971, and 3,623,871 of Raphael Karel van Poucke, Marcel Jacob Monbaliu, Hans Glockner and Ernst Meier, issued Nov. 30, 1971.
2-equivalent or 4-equivalent colour couplers for cyan are usually of the phenol or naphthol type. Particularly suitable are the colour couplers described in French Pat. No. 2,078,920 filed Feb. 22, 1971 by Gevaert-Agfa N.V., in British Pat. No. 1,004,281 filed Feb. 15, 1961 by Gevaert Photo-Producten N.V. and in U.S. Pat. Nos. 3,079,256 of Raphael Karel Van Poucke, Arthur Henri De Cat and Marcel Hendrik Verbrugghe, issued Feb. 26, 1963, 3,226,230 of Raphael Karel Van Poucke, Hector Alfons Vanden Eynde and Arthur Henri De Cat, issued Dec. 28, 1965, and 3,488,193 of Hector Alfons Vanden Eynde and Arthur Henri De Cat, issued Jan. 6, 1970.
The hydrophilic colloid used as the vehicle for the silver halide emulsion layer and the other hydrophilic colloid layers may be, for example, gelatin, colloidal albumin, zein, casein, a cellulose drivative, a synthetic hydrophilic colloid such as polyvinyl alcohol, poly-N-vinyl pyrrolidone, etc., gelatin being preferred. If desired compatible mixtures of two or more of these colloids may be employed.
The silver halide emulsion layer may comprise various silver salts as the sensitive salt such as silver bromide, silver chloride, silver chlorobromide, silver bromoiodide and silver chlorobromoiodide.
The photographic colour elements comprising the polymeric competing couplers of the present invention may comprise as supports paper, glass, cellulose ester film, polyvinyl acetal film, polystyrene film, polyethylene terephthalate film and related films of resinous materials.
In the development of the exposed photographic colour materials aromatic primary amino developing agents are used forming dyestuffs with the colour couplers incorporated in the photographic material and colourless compounds with the polymeric competing couplers of the present invention. Suitable developing agents are p-phenylene diamine and derivatives e.g. N,N-diethyl-p-phenylene diamine, N-butyl-N-sulphobutyl-p-phenylene diamine, 2-amino-5-diethylaminotoluene, 4-amino-N-ethyl-N(β-methane sulphonamidoethyl)-m-toluidine, N-hydroxyethyl-N-ethyl-p-phenylene diamine, etc.
The following example illustrates the use of the polymeric competing couplers of the invention in photographic silver halide colour material.
EXAMPLE
A photographic multilayer negative material A was composed as follows:
1. a common film support,
2. two red-sensitized silver halide emulsion layers each containing a colour coupler for cyan and a mask-forming compound, the undermost emulsion layer being of lower speed than the uppermost emulsion layer,
3. an intermediate gelatin layer,
4. two green-sensitized silver halide emulsion layers each containing a colour coupler for magenta and a mask-forming compound, the undermost emulsion layer being of lower speed than the uppermost emulsion layer,
5. a yellow gelatin filter layer,
6. two non-spectrally-sensitized blue-sensitive silver halide emulsion layers each containing a yellow-forming colour coupler, the uppermost emulsion layer having higher speed than the undermost emulsion layer, and
7. a protective gelatin coating.
For comparison purposes a material B was prepared in exactly the same way as material A with the only difference that both the gelatin-intermediate layer and the filter layer comprise per sq.m an amount of polymeric competing coupler according to preparation 13 corresponding to 1 millimole of polymerized monomeric coupler.
Samples of both materials were exposed to a wedge through a blue, green and red filter and subjected to common negative colour processing for the formation of the yellow, magenta and cyan separation images. The developing agent used was 2-amino-5-[N-ethyl-N(β-methylsulphonylamino)ethyl]amino toluene sulphate.
The separation images of material B showed markedly purer colours than those of material A.