DE2012095A1 - Replacing gelatin as binder in photographic emulsion - Google Patents

Abstract

Photographic silver halide emulsion contains as binder a macromolecular amphoteric electrolyte that has been obtained by copolymerisation of a vinyl cpd. contg. carboxyl or sulphonic acid gps (with the exception of acrylic acid and its derivs). an acrylamide or its derivs and a vinylimidazole or its derivs. Electrolyte serves as protective colloid, does not decompose or support mould growth and has constant physical-chemical properties.

Description

Silver halide photographic emulsion The invention relates to a light-sensitive silver halide emulsion which can be used as a binder instead of photographic Gelatin contains a macromolecular amphoteric electrolyte that polymerizes through interpolymerization of three types of vinyl monomers, namely acrylamide or derivatives thereof., vinylimidazole or derivatives thereof and a vinyl compound having a carboxyl or sulfonic acid group in place of the photographic gelatin. These macromolecular amphoteric electrolytes serve as an excellent protective colloid for the silver halide and, unlike gelatine, do not mold or decompose and deliver furthermore constant physicochemical and photographic properties.

From "Journal of Japan Photographic Society", Volume 29, No. 1, page 30 is only a mixed polymer of acrylamide, acrylic acid and vinylimidazole derivative known, which has a similar protective effect as gelatin.

It has now been found that a copolymer composed of a vinyl compound with carboxyl or sulfonic acid groups, except acrylic acid, acrylamide or a derivative thereof, and vinylimidazole or a derivative thereof have an excellent protective effect and used in a silver halide emulsion instead of gelatin can. In this case, the isoelectric point can be freely in a wider range by choosing suitable compounds than when using acrylic acid or derivatives be chosen from here.

The interpolymerization of these three types of monomers can be carried out in known manner using persulfates, hydrogen peroxide, etc. as Start substance to be executed.

Typical examples of vinyl compounds which can be used in the present invention with carboxy or sulfonic acid groups are p-styrenesulfonic acid, vinylsulfonic acid, Maleic acid, fumaric acid, itaconic acid, etc.

Examples of useful acrylamide compounds and derivatives thereof are acrylamide, N-methylacrylamide, N-dimethylacrylamide, $ N, N-diethylacrylamide, $ N-ethylacrylamide, N-} iydroxyäthylacrylamid, N-} iydroxyätiiyl-nmethylacrylamid, 0c-acetamide acrylamide, N -Methylacrylamide (methacrylamide), N, N-dimethyl methacrylamide, N, N-diethyl methacrylamide, N-methyl methacrylamide, N-ethyl acrylamide, N-hydroxyethyl-N-methyl methacrylamide, N-methoxymethacrylamide, N-acetamide acrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-acetamide methacrylamide etc.

Examples of vinylimidazoles and derivatives which can be used according to the invention of these are 1-vinyl-2-methylimidazole, 1-vinyl-2-ethylimidazole, 1-vinyl-2,4-dimethylimidazole, 1-vinyl-2-ethyl-4-methylimidazole, 1-vinyl-4- (5) -ß-hydroxyethylimidazole, 1-vinyl-2-hydroxyethylimidazole, 5-vinylimidazole, etc.

Of the three vinyl monomers, acrylamides or derivatives thereof impart the polymer obtained has good hydrophilic properties and protective colloid effect and the vinyl imidazoles or derivatives thereof cause strong repressions the growth of silver halide crystals. Carboxyl and sulfonic acid groups work contrary to the growth-preventing effect of the imidazole groups. For this reason can be the effect of the copolymer on the growth rate of the photosensitive Silver halide crystals by properly selecting the proportions of the three Components are affected. This way you can see the crystal growth rate of the silver halide emulsion to the same value as when using gelatin.

Furthermore, you can increase the amount of imidazole or the amount decrease the acid groups to increase the crystal growth preventive effect; on the other hand, you can increase the amount of acid groups or the amount of imidazole decrease to decrease the anti-growth effect.

There is no limit to the proportions of each Components. However, if you have an extremely strong prevention of crystallization wants to achieve, the imidazole content should be practically less than 10 mol%, the one of the acid groups less than 20 mol% and that of the acrylamide or a derivative of this amount to more than 70 moles. The content of mixed polymers in the emulsion should be preferably less than 40%.

The mixed polymer of the three vinyl monomers assigns an affinity Gelatin and for this reason the silver halide emulsion of the present invention can at the same time contain gelatin and the mixed polymer as a binder.

In order to prevent adverse photographic properties such as fogging in the emulsion, etc., which are caused by the peroxides used as the starter substance, an aromatic amino compound or a derivative thereof of the following general formula can be used together with the polymer: In the above formula, R represents an aryl group or an aryl group substituted by alkyl, alkoxy, halogen, etc., and R1 and -R2 each represent hydrogen, alkyl, hydroxyalkyl, etc. It has also been found to have adverse photographic properties such as fogging and hindrance the sensitization and change in the physical properties of the photosensitive film due to a reaction between the polymers can be reduced or avoided if the mixed polymer of the three vinyl monomers, which is made using ammonium persulfate, potassium persulfate, hydrogen peroxide, etc. as the starter substance in a known manner Thermal polymerization had been produced with such an amino compound as e.g. Aniline, monomethylaniline, dimethylaniline, monoethylaniline, diethylaniline, toluidine, anisidine, di-ß-hydroxyethylaniline, ß-naphthylamine, etc. was added and optionally heated, and then used in a silver halide emulsion.

Radical polymerization catalyzed by peroxide can also be used cancel at a certain stage by adding these compounds.

The amount of these compounds to be added is not particularly critical, but preferably they are used in an amount equivalent to the starting substance on, -da if a smaller amount is used, it is not sufficient Effect is achieved and in some cases disadvantageous photographic properties remain. On the other hand, if the amount of the amino compound exceeds that of the Starter substance, no significant adverse photographic effects are generally observed Properties, but there is an increased coloration. The effect of the addition This connection is greatest when it is opened immediately after the termination of the Polymerization adds, the amount required also being the lowest. the Implementation by which the disadvantageous photographic properties are eliminated is not momentary, but requires a certain amount of time. This time however, it can be shortened by heating.

The invention will now be explained further with the aid of the following examples: Example 1 (1) Preparation of polymer The following liquid first became prepared: acrylamide 43.8 g 2-i [, ethyl-1-vinylimidazole 5.4 g maleic acid 38.5 g dimethylformamide 87.7 g benzoyl peroxide 0.5 g This liquid was heated to 70 ° C. for 4 hours in a stream of nitrogen and polymerized in this way. Acetone was then added and the polymer was precipitated, which was then separated off and dried.

(2) Preparation of Emulsion The following three liquids A, B and C were prepared; liquids A and B were heated to 500C and liquid C was heated to 400C. 10 * aqueous solution of the Polymers 40 g Liquid water 110 g A / citric acid 1 g 6 6 n caustic soda ig Silver nitrate 10 g Liquid distilled water 50 g B lead nitrate (50% aqueous solution) 2 g Liquid sodium chloride 4.5 g Cadmium chloride 2.5 g Water 50 g The liquid B was added to the liquid A with stirring, and after the lapse of one minute, the liquid C was added. The mixture was digested at 50 ° C. for 35 minutes. Then 5 ml of 1% potassium iodide solution was added and digestion was continued for 20 minutes to obtain an emulsion suitable for photographic contact printing papers.

Example 2 (1) Preparation of the polymer The following two solutions were prepared: The first acrylamide 63.8 g Solution # 1-vinyl-2-methylimidazole 5.4 g # Vinysulfonic acid 5.4 g # 70% aqueous nitric # acid solution 4.5 g Water 70 g The second water 348 g Ammonium persulfate solution 0.4 g The second solution was heated to 90 ° C. in a stream of nitrogen and the first solution was then added dropwise over the course of an hour. The solution was then heated to 90 ° C. for a further hour and then cooled. The solution was then added to five times the amount of Methanel, the polymer precipitating tiiiI 1 iti'iiti (t.ickit wu <o (2) Preparation of the photosensitive emulsion The following three solutions were prepared: Solution A: (6000) 10% ige aqueous solution of the polymer 40 g water 110 g citric acid 6 N aqueous solution of the polymer 1 g solution B: (6000) silver nitrate 10 g distilled water 50 g lead nitrate (5% aqueous solution 2 g solution C: (50 ° C) sodium chloride 4 , 5 g potassium chloride 3.5 g cadmium chloride (10 aqueous solution) 10 g water 50 g The solution B was added with stirring to the solution A over one minute, and the solution C was then added over another minute the solution was digested for 55 minutes at 60 ° C. Then 5 ml of a 1% potassium chloride solution was added to 5 ml of a 0.01% sodium thiosulfate solution, and the solution was digested for 20 minutes to obtain an emulsion suitable for enlarging paper was th.

Example 3 (1) Preparation of the polymer ES, the following solution was made prepared: acrylamide 5D, 2 g of ethyl 1-vinylimidazole, 6.2 g of fumaric acid 63, g of dimethylformamide 327.3 g benzoyl peroxide 0.5 g The above solution was 7 hours in a nitrogen atmosphere heated to 70 ° C and polymerized in this way. Then the obtained interpolymer was with Acetone precipitated and dried after separation.

(2) Preparation of the emulsion A 10% aqueous solution of the copolymer was prepared according to the method described in Example 1, one for Contact prints suitable emulsion was obtained.

Example 4 (1) Preparation of polymer The following two were made Solutions made: First solution: Acrylamide 63.8 g 5-vinylimidazole 4.9 g potassium p-styrenesulfonate 11.1 g water 79.6 g Second solution: water 375 g ammonium persulfate 0.4 g The second solution was heated to 90 ° C. and the first solution became the second solution was added dropwise over the course of one hour. The solution obtained was heated to 900C for one hour and then cooled. The interpolymer was made by adding precipitated 5 times the amount of methanol and dried after separation.

(2) Preparation of the emulsion A 10% aqueous solution of the polymer was prepared according to the procedure described in Example 2, one for An emulsion suitable for enlargement purposes was obtained.

Example 5 The method for preparing a polymer according to Example was repeated except that 0.5 g of di-ß-hydroxyethylaniline was added to the liquid were added, which by heating for four hours at 700G polymerized and then heated to 700C for a further 50 minutes. After that was acetone admitted.

The emulsion thus obtained had none of the residuals Starting substance caused fogging.

Example 6 The polymerization process according to Example 2 was repeated, however, 0.25 g of diethylaniline was added to the solution heated to 90 ° C. for 1 hour and the solution was then heated to 7,000 for another half hour. It was then cooled and methanol was added. The emulsion thus obtained showed no fogging caused by residual starter substance.

Example 7 The polymerization process according to Example 3 was repeated, however, 0.3 g of di-ß-hydroxyethylaniline was added to the polymerized solution became; it was then heated to 70 ° C. for 30 minutes and then cooled. The one here obtained emulsion showed no fogging.

Example 8 The polymerization process according to example 4 was repeated, however, 0.3 g of dimethylaniline was added to the solution heated to 90 ° C. for 1 hour became; the mixture was then heated to 70 ° C. for 50 minutes.

It was then cooled and methanol was added. A haze did not occur in the product obtained in this way.

he macromolecular amphoteric described in the above examples Electrolyte can of course also be used in color photography0

Claims (7)

Claims: S silver halide photographic emulsion consisting of from a macromolecular amphoteric electrolyte, which is polymerized by interpolymer a vinyl compound containing carboxyl groups or sulfonic acid groups, with Except for acrylic acid and derivatives thereof, an acrylamide or derivatives thereof and vinylimidazole or derivatives thereof as binders. 2. Photographic silver halide emulsion according to claim 1, daduch characterized in that the content of imidazole groups is less than 10 mol%, the content of acid groups less than 20 mol% and the content of acrylamide or derivatives thereof is over 70 mol%. 3. The silver halide photographic emulsion of claim 1 characterized characterized in that they are p-styrene sulfonic acid, vinyl sulfonic acid, Contains maleic acid, fumaric acid, itaconic acid, crotonic acid or p-styrene carboxylic acid. 4. The silver halide photographic emulsion of claim 1 characterized characterized in that the acrylamide or derivative thereof is made from acrylamide, N-FIethylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-ethylacrylamide, N-hydroxyethylacrylamide, N-hydroxyethyl-N-methylacrylamide, α-acetamide acrylamide, 0c-methylacrylamide (methacrylamide), N, N-dimethyl methacrylamide, N, N-diethyl methacrylamide, N-methyl methacrylamide, N-ethyl acetate acrylamide, N-hydroxyethyl-N-methyl methacrylamide, N-methoxymethacrylamide, N-acetamide acrylamide, N-methylol acrylamide, N-methylol methacrylamide or N-acetamide methacrylamide. 5. The silver halide photographic emulsion of claim 1 characterized characterized in that the vinylimidazole or derivative thereof from 1-vinyl 2-methylimidazole, 1-vinyl-2-ethylimidazole, 1-vinyl-2,4-dimethylimidazole, 1-vinyl-2-ethyl-4-methylimidazole, 1-vinyl-4 (5) -ß-hydroxyethylimidazole, 1-vinyl-2-hydroxyethylimidazole or 5-vinylimidazole consists. 6. A silver halide photographic emulsion according to claim 1, characterized in that it is an aromatic amino compound or a derivative thereof represented by the following general formula in which a is an aryl group or an aryl group substituted by alkyl, alkoxy, halogen, etc., and R1 and R2 each represent hydrogen, alkyl, hydroxy, etc., together with the copolymer as a binder. 7. The silver halide photographic emulsion of claim 6 characterized characterized in that they are di-ß-hydroxyethylaniline as the aromatic amino compound contains.