JPS6116968B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for precipitation of silver halide emulsions, and more particularly to a method for coagulation and precipitation of silver halide emulsions, which can be used to remove excess water-soluble salts from physically ripened silver halide emulsions. Preparation of photographic silver halide emulsions generally consists of the following three steps. That is, physical ripening: making silver halide crystals by reacting a water-soluble silver salt and a water-soluble alkali halide in the presence of a binder such as gelatin, washing with water: removing unnecessary water-soluble salts, and chemical ripening: The surface of the formed silver halide crystals is chemically treated with chemicals to increase sensitivity. The above-mentioned water washing method generally involves cooling the silver halide emulsion formed by
This is then shredded to make noodles, which are washed with cold water under conditions that do not dissolve the noodles, and excess unnecessary salts are removed by osmotic pressure, or left in liquid form by dialysis using a semipermeable membrane. I went by means. However, such a method requires a long time to work, and furthermore, it has disadvantages such as low desalination efficiency since it requires a large amount of water for washing. In addition, in the above method, gelatin may flow out during the water washing process unless a certain degree of physical strength is imparted to the gelled emulsion. The ratio could not be increased beyond a certain point. Therefore, as a method that does not involve the desalting method, which has many drawbacks, an appropriate precipitating agent is added to the silver halide emulsion, the silver halide emulsion is precipitated by adjusting the pH, and then the supernatant is separated. A method has been proposed in which excess salts in a silver halide emulsion are removed by washing the precipitate with water. Among these methods, representative methods include gelatin and, for example, carboxyhalides, acid anhydrides, isocyanates, bromoacetic acids, alkanesultones, vinylsulfonamides, maleimide compounds,
Examples include a method in which a gelatin derivative obtained by reacting with polyalkylene oxides, epoxy compounds, etc. is used as a silver halide emulsion. Specifically, U.S. Patent No. 2614928;
3132945, 3186846, 3312553, British Patent No. 861414, 1005784, 1033189
It is written in the number etc. However, in these methods, when producing gelatin derivatives, phthalic anhydride, benzoic anhydride,
Acid anhydrides such as maleic anhydride, succinic anhydride, and chloromaleic anhydride; isocyanides such as phenyl isocyanate, P-tolyl isocyanate, P-bromophenyl isocyanate, P-chlorophenyl isocyanate, and naphthyl isocyanate; nates, phthalyl chloride, benzoyl chloride, P-nitrobenzoyl chloride, P
- Carboxyhalides such as carboxybenzoyl bromide are dissolved in common organic solvents such as ascent, dimethylformamide, diyl-butyl phthalate, etc., so when washing silver halide emulsions with water, organic solvents such as those mentioned above are used together with water-soluble salts. This is not a good thing from an environmental conservation point of view. In addition, in these methods,
Another drawback is the following. In other words, gelatin derivatives produced by the reaction of amino groups such as lysine residues in gelatin molecules with, for example, phthalic anhydride, have active groups already occupied by the reaction, so the gelatin coating A crosslinking reaction with gelatin hardening agents (e.g., formalin, glyoxal, mucochloric acid, mucobromic acid, divinyl sulfones, aziridines, epoxies, halogen-substituted triazines, etc.) used to improve physical properties does not occur, and as a result, gelatin Silver halide emulsions that contain a large amount of derivatives cannot be expected to achieve the desired degree of hardness even when they interact with gelatin hardeners, and fog is more likely to occur than emulsions prepared using ordinary gelatin. be. Further, in this case, silver halide emulsions in which the ratio of gelatin to a certain amount of gelatin derivative is increased causes a curl phenomenon or a decrease in resolution. In addition to these gelatin derivatives, methods have been proposed in which polymer compounds such as vinyl polymers are used as precipitating agents. For example, U.S. Patent No. 3137576
British Patent No. 945334, British Patent No. 3178294, British Patent No. 945334, British Patent No.
It is described in No. 981251, Special Publication No. 40-21020, No. 46-43429, etc. These polymers are capable of coagulating silver halide emulsions through intermolecular attraction and causing the coagulated product to precipitate, and are mechanically distinguished from gelatin derivatives. However, it is not very easy to redisperse a silver halide emulsion coagulated with a vinyl polymer or the like in an aqueous medium. Moreover, the resulting photographic elements have the disadvantage of exhibiting a tendency to fog. An object of the present invention is to provide a novel method for precipitation of silver halide emulsions, which improves the various drawbacks mentioned above. Another object of the present invention is to provide a method for precipitation of silver halide emulsions that can be used to remove excess water-soluble salts from silver halide emulsions. Another object of the present invention is to provide a precipitation agent for silver halide emulsions. These objects of the invention are:
(However, using an Ubbelohde viscometer at 30±0.5℃
The values are shown as measured as a 1% solution in a 0.1 mol/aqueous sodium chloride solution. ) is achieved by using a polymer having repeating units represented by the following general formula [ ] as a precipitant for a silver halide emulsion. general formula In the formula, M represents a hydrogen atom, an alkali metal atom (for example, a sodium atom, a lithium atom, etc.) or an ammonium atomic group. n is 1, 2 or 3
shows. The molecular weight of the polymer having a viscosity number of 0.05 to 0.50 used in the present invention is 1000 to 100000, preferably 0.10 to 0.10.
0.30, and its molecular weight is 2000-40000. If a polymer with a viscosity number exceeding 0.50 is used, the re-solubility of the formed precipitate will be poor, making it impossible to obtain the desired silver halide emulsion. Also, the viscosity number
If it does not reach 0.05, no change will be obtained in the mixture. The polymer used in the present invention may be a homopolymer or a copolymer as long as the repeating unit represented by the above general formula is contained in the molecule in an amount of 5 mol % or more, preferably 50 mol % or more. In the case of a copolymer, monomers to be copolymerized include methacrylic acid, acrylic ester, acrylic acid, maleic anhydride, maleic acid, maleic acid half alkyl ester, methyl vinyl ether, methyl vinyl Kent, N-vinyl pyrrolidone, N-vinyl caprolactam, acrylamide, N/N-dimethylacrylamide, diacetone acrylamide, N-methylolacrylamide, methylenebisacrylamide,
Acryloylmorpholine, vinyl chloride, vinylidene chloride, ethylene, propylene, isobutylene,
Diisobutylene, tetramethylbutadiene, acrolein, methacrolein, acrylonitrile,
Vinyl acetate, vinyl propionate, vinyl butyrate, chloroethyl vinyl ether, styrene, vinyltoluene, divinylbenzene, ethylene glycol methacrylate, itaconic acid, itaconic acid ester, vinyl imidazole, N-vinyl-2-methylimidazole, vinyl pyridine,
N・N-dimethylaminoethyl methacrylate,
N・N-diethylaminoethyl acrylate,
N・N-diethylaminoethyl methacrylate,
Examples include maleic acid (4-phenoxy-3-sulfophenyl) hydroxide. Next, typical examples of the polymer used in the present invention are listed below. Of course, the present invention is not limited to these. Compound example (sedimentant example) Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers with repeating units of Polymers having repeating units of
It is written in the number etc. In general, the benzyl sulfonate in the polymer has a m-position of about 60
%, and contains about 40% of the P-position, but the present invention is not limited to this. The polymer used in the present invention is preferably added to the silver halide emulsion after physical ripening in a proportion of 10% by weight or more, preferably 20 to 50% by weight, based on the gelatin. may be added to the gelatin solution before or during precipitation,
It may also be added during physical ripening. The silver halide emulsion containing the polymer is PH-treated with a suitable acid such as citric acid, phosphoric acid, hydrochloric acid, acetic acid, or sulfuric acid.
When the value is lowered and adjusted generally to PH 2.0-5.0, rapid precipitation of silver halide crystals occurs with gelatin or other peptizing substances. On this occasion,
Preferably, citric acid is used as the acid. The sediment resulting from such settling contains only a small amount of water and the desalting step is therefore completed by decanting the supernatant, but if necessary the sediment may be rinsed with cold water once or several times. It may be washed, or the water-soluble salts can be removed by redissolving the washed precipitate in water or an aqueous medium and repeating the above operations. Further, by using it in combination with an aggregation promoter, the precipitation operation of the silver halide emulsion can be carried out efficiently. The silver halide emulsion precipitate, which has been precipitated by the method of the present invention and has been sufficiently desalted, can be redissolved in an aqueous medium by adding hot water while stirring or by increasing the pH value. This re-dissolved silver halide emulsion can be subjected to conventional chemical thermal formation, if necessary. The silver halide emulsion that can be applied to the present invention may be a conventional surface latent image type emulsion, or may be a silver halide emulsion that can be used in the present invention.
The internal latent image type described in No. 2592250 may also be used.
These silver halide emulsions include silver chloride, silver chlorobromide,
Dispersion consisting of silver chloroiodide, silver bromoiodide, silver iodochlorobromide, etc. (0.3 microns or less), coarse (0.3 microns or more), or ultrafine (0.03 microns or less) crystals uniformly or polydispersed. It can be used as Aqueous peptizing substances such as gelatin, gelatin derivatives, albumin, casein, hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfate, alginic acid or its salts (such as sodium salts), polyvinyl alcohol, polyvinyl alcohol, etc. can be used as binders for dispersing such silver halide crystals. -N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyvinylimidazole, polyvinylpyrazole, copolymers of these synthetic polymers, etc. can be used alone or in combination. The method of precipitating such silver halide crystals in an aqueous peptizer is characterized by the method of introducing a reactant, that is, the single-jet method and the double-jet method. These methods are called "Photographic Chemistry"
(“Photographic chemistry”), Pierre Glatides
Author, Fountain Press, London (1958) No. 327~
330 pages, “New Creation in Silver Bromide Precipitation”
(“Nucleation in Silver Bromide”
Precipitation”), CRBerry and PCSkillman
Co-author, J.Phys.Chem. Vol. 68, pp. 1138-1143 (1964); "The Theory of the Photographic Process"
Photographic Process”), 3rd edition, CEKMees
and TH James (1966), p. 34; US Pat. No. 3,782,954, US Pat. No. 3,785,777, etc. The redissolved silver halide emulsion is prepared as a coating solution by an appropriate method, and at this time, it can be chemically ripened if necessary. The silver halide emulsion for the coating solution contains various photographic additives, such as West German Published Specification No. 2057941 and West German Publication No. 2057941.
No. 2163812, JP-A-47-26133, JP-A No. 48-29432
No. 48-66834, No. 48-66835, No. 48-
Yellow couplers described in No. 94432, No. 49-1229, No. 49-10736, etc., US Patent No. 3684514,
British Patent No. 1183515, Special Publication No. 40-6031, No. 40
-6035, 44-15754, JP-A-49-29639,
No. 49-55437, No. 49-117034, No. 49-123033
The magenta coupler described in the US Patent No.
Cyan couplers described in Japanese Patent Publication No. 2423730, No. 2801171, Japanese Patent Publication No. 16056/1983, etc., U.S. Patent No.
No. 2685512, No. 2739888, No. 2784087, No. 3250617, No. 3253921, No. 3352681,
No. 3533794, No. 3692525, German Patent No.
1087902, German Publication Specification No. 2049289, German Publication No. 2049289,
Ultraviolet absorbers described in No. 2151098, JP-A-47-1026, etc., U.S. Pat. No. 2336327, U.S. Pat. No. 2360290
No. 2403721, No. 2418613, No. 2418613, No. 2403721, No. 2418613, No.
No. 2704713, No. 2728659, No. 2732300, No. 2735765, No. 3432300, No. 3573050,
No. 3574627, Special Publication No. 49-20977, No. 50-
23813, JP-A No. 51-6024, etc.; fluorescent brighteners, as described in U.S. Pat. No. 3,630,738, etc.; anti-halation or irradiation dyes, as described in U.S. Pat. No. 3,651,494, etc. , other stabilizers (5-hydroxy-1.3.3a.7-tetrazaindene, triazaindenes, etc.), anti-capri agents (mercaptotriazoles), etc. can be included. Also, as a gelatin hardening agent,
For example, U.S. Patent Nos. 2327760, 2964404, 3220848, 2726162, 3091513,
Same No. 3179517, Same No. 1870354, Same No. 2080019
No. 2726162, No. 2870013, No. 2870013, No. 2726162, No. 2870013, No.
No. 2983611, No. 2992109, No. 3047394, No. 3057723, No. 3103437, No. 3321313,
Same No. 3325287, Same No. 3362827, Same No. 3539644
British Patent No. 676628, British Patent No. 3543292, British Patent No. 676628, British Patent No.
No. 825544, No. 1270578, German Patent No. 872153
No. 1090427, Special Publication No. 43-7133, No. 46-
1872, etc., and these gelatin hardeners are preferably added immediately before coating, generally within 10 minutes, preferably within 5 minutes, particularly within 30 seconds. This method of immediately adding a gelatin hardener is described in JP-A-53-55022 and JP-A-53-76019. The silver halide emulsion for coating liquid is patented in the U.S. Patent No.
No. 2108485, No. 2161331, No. 3149105, No. 2269234, No. 2270378, No. 2442710,
Same No. 2454629, Same No. 2776280, Same No. 2213995
No. 2493748, No. 2519001, British Patent No.
424559, 660408, 742112, German Patent No. 929080, other US Patent No. 1939201,
It may or may not contain the cyanine or merocyanine dyes described in Patent No. 2072908, Patent No. 2739149, Patent No. 2945763, etc.
Further, chemical sensitization can be carried out by any method. For example, it may be aged with natural active gelatin or sulfur compounds may be aged in US Pat.
No. 1,623,499 and the like. Also, ruthenium, rhodium,
It may also be prepared with salts of noble metals such as palladium, iridium and platinum. Additionally, U.S. Patent No.
Chemical sensitization with gold salts may be used as described in US Pat. No. 2,399,083, or gold salts may be used as stabilizers as described in US Pat. No. 2,597,856. Preferred gold salts include potassium chloroaurite, potassium gold thiocyanate, potassium chloride-auric hydroxide, and gold trichloride.
In addition, reducing agents such as stannous salts described in U.S. Pat. No. 2,487,850, polyamines such as diethylenetriamine described in U.S. Pat. No. 2,521,926, and selenium compounds described in U.S. Pat. No. 3,297,446 may also be used. I can do it. The silver halide emulsions obtained by the method of the invention can be used in all kinds of photographic elements, such as color positive films, color negative films, color papers, color reversal photographs, color diffusion transfer process photographs, silver dye bleached photographs, black positive films, black and white. Photographic paper, photographs for X-ray recording, materials for forming photo-developable printed images, photographs for printout recording, photographs for plate making (for example, lithographic film, etc.), photographs for cathode ray tubes, etc. can be made. Next, synthesis examples of typical polymers used in the present invention will be shown, but the present invention is not limited thereto. Synthesis Example 1 (Synthesis of the above-mentioned exemplary compound (1)) Sodium vinylbenzyl sulfonate 220g
(manufactured by Kiyomi Kagaku Co., Ltd.), 1750 g of distilled water, 240 g of isopropyl alcohol, and 2.2 g of potassium persulfate as a polymerization initiator were introduced into a reactor for No. 3, and stirred at 70°C for 8 hours while blowing nitrogen gas. A combined solution was produced. The obtained polymer was reprecipitated in acetone, taken out as a powder, and dried. The obtained polymer powder was dissolved in 0.1 mol/aqueous sodium chloride solution to make a 1% solution of 30±0.5
The viscosity number of the above polymer was measured at °C using an Ubbelohde viscometer and was found to be 0.12. Synthesis Example 2 (Synthesis of the Exemplified Compound (1) having a different degree of polymerization from the polymer obtained in Synthesis Example 1) Synthesis was carried out in the same manner as in Synthesis Example 1, except that 300 g of isopropyl alcohol was used. The viscosity of the obtained polymer was measured using the same method as in Synthesis Example 1, and was found to be 0.08. Synthesis Example 3 (Synthesis of the above exemplary compound (5)) 180 g of sodium vinylbenzyl sulfonate,
15g acrylamide, isopropyl alcohol
250g and 3.0g potassium persulfate as a polymerization initiator
When reacted in the same manner as in Synthesis Example 1, the obtained copolymer had a viscosity number of 0.43. (The method for measuring the viscosity number is the same as that used in Synthesis Example 1 above.) Synthesis Examples 4 to 8 The monomers used in Synthesis Example 3 were replaced with the exemplified compounds (5), (7), and (8), respectively. ), (9), and (10) were synthesized. The viscosity number (1%) of the obtained polymer is shown in Table 1 below. (The method for measuring the viscosity number is the same as that used in Synthesis Example 1 above)

【table】

[Table] Next, the present invention will be explained in detail using Examples. Example 1 200g of 2% gelatin solution was added with 2 listed in Table 2 below.
% polymer (or copolymer) solution was added, and 1N hydrochloric acid was added dropwise to this mixed solution.The pH at which the precipitate started to precipitate was measured. These results are shown in Table 2. (In addition, 1N indicates 1 regulation.)

[Table] In addition, in order to measure the re-solubility of the sediments generated in Test Nos. 1 to 6, 3 g of each sediment was dissolved in 100 ml of warm water at 40°C under stirring to ensure that the sediments were uniformly dissolved. The time it took to do so was measured. A blue pigment was previously dispersed in each sediment so that the resolubility of the sediment could be visually observed.
These results are shown in Table 3 below.

[Table] As is clear from Table 2, the polymer according to the present invention having a viscosity number in the range of 0.05 to 0.50 has a sufficient sedimentation effect on gelatin (Test Nos. 1 to 5), and the resolubility of this sediment. is excellent (test
Nos. 9 to 13), but even for polymers with similar compositions, those with a viscosity exceeding the above range had extremely poor re-dissolution of the resulting precipitate (test
No.16). Further, as is clear from Table 3, the re-dissolution of the precipitate produced by polymers other than the present invention was poor regardless of the viscosity number (Test Nos. 6 to 7). Example 2 A solution and a solution were prepared according to the following recipe.

[Table] Next, the solution was heated to 60°C, and the solution was added over 30 minutes while stirring. The addition was carried out at a constant rate, during which time the temperature of the reaction solution was maintained at 60°C, and physical ripening was performed for 40 minutes. The average grain size of the silver halide crystals thus obtained was about 0.5 microns. After aging, cool to 40℃ and measure the viscosity number.
20 ml of an aqueous solution containing 2 g of the above-mentioned Exemplary Compound (1) with a molecular weight of 0.12 was added to the silver halide emulsion produced above, and after thorough stirring, the pH was lowered to 4.3 and the silver halide dispersion was precipitated. The mother liquor was removed by decantation and the precipitate was washed three times with cold water for a total of 3 minutes.
Next, add 50g of activated gelatin containing hypo, which has been swollen with water, dissolved in warm water at 40°C, add water at 40°C until the total volume is 1, and then
The pH was raised to 6.8 and redissolved with 1N sodium hydroxide solution. This was chemically aged at 60°C for 30 minutes.
After formalin was added thereto, it was coated on photographic baryta paper to a silver content of 2 g/m ² and dried to prepare a photographic element, which was designated as Sample 1. Sample 2 was a sample prepared in the same manner as Sample 1 except that the timing of addition of Exemplified Compound (1) having a viscosity number of 0.12 to the solution was set. Sample 3 was prepared in the same manner as Sample 1 except that 2 g of the Exemplified Compound (4) having a viscosity of 0.43 was used in place of the Exemplified Compound (1) having a viscosity of 0.12 used in preparing Sample 1. Sample 4 was prepared in the same manner as Sample 1 except that 2 g of the Exemplified Compound (8) having a viscosity of 0.18 was used in place of the Exemplified Compound (1) having a viscosity of 0.12 used in preparing Sample 1. Sample 5 was prepared in the same manner as above except that 2 g of the above-mentioned Exemplified Compound (10) having a viscosity number of 0.22 was used in place of the Exemplified Compound (1) having a viscosity number of 0.12 used in preparing the above-mentioned Sample 2. Next, the following comparative samples were created. The solution was heated to 60° C. and added to the solution over 30 minutes while stirring. The addition was carried out at a constant rate, during which time the temperature of the reaction solution was maintained at 60°C, and physical ripening was performed for 40 minutes. The average grain size of the silver halide crystals thus obtained was about 0.5 microns. After ripening, it was cooled to 40°C, and 20 ml of a 10% acetone solution of phthalic anhydride adjusted to pH 11 with 1N sodium hydroxide solution was added to the silver halide emulsion produced above, and after stirring thoroughly,
The solution was cooled to 25° C., and the pH was lowered to 3.6 with 1N hydrochloric acid to precipitate the silver halide dispersion. The mother liquor was removed by decantation and the precipitate was washed with cold water for a total of 3 minutes. Next, 50 g of active gelatin containing Hypo, which has been swollen with water in advance, dissolved in warm water at 40°C is added, water at 40°C is added until the total volume reaches 1, and the pH is adjusted to 6 with 1N sodium hydroxide solution. 5 and redissolved. This was chemically aged at 60°C for 30 minutes. After formalin was added to this, it was coated on photographic Paraita paper to a silver content of 2 g/m ² and dried to prepare a photographic element, which was designated as Comparative Sample 1. Comparative sample 2 was prepared in the same manner as above except that phenyl isocyanate was used in place of phthalic anhydride used in preparing comparative sample 1. Comparative polymer (1) with a viscosity number of 0.13 was used in place of the exemplified compound (1) with a viscosity number of 0.12 used in preparing Sample 1.
Comparative sample 3 was prepared in the same manner except that 2g of was used. Comparative polymer (1) with a viscosity number of 0.82 was used in place of the exemplified compound (1) with a viscosity number of 0.12 used in preparing Sample 1.
A comparative sample was prepared in the same manner except that 2g of was used. In addition, as a control sample, the exemplified compound (1) with a viscosity number of 0.12 used in preparing Sample 1 was not added, and the desalting treatment was carried out by cooling the obtained silver halide emulsion (5°C) and setting it. This was shredded to make noodles, and the noodles were washed with cold water for a long time (about 1 hour). Other than this, it was prepared in the same manner as Sample 1 above. Each of these samples was exposed through a continuous wedge using an NGS-type sensitometer and developed with the following developer for 20 minutes.
Developed for 10 minutes at ℃. Developer N-methyl-P-aminophenol sulfate 2.2g Hydroquinone 8.8g Anhydrous sodium sulfite 40g Anhydrous sodium carbonate 48g Add water to make 1 After washing with water, treat with the following fixer at 20℃ for 10 minutes and wash with water. did. Fixer Sodium thiosulfate 200g Borax sand 10g Add water to make 1 Fog and sensitivity were measured from the obtained image.
Sensitivity was measured based on the density point of fog +0.2, and expressed as relative sensitivity with the sensitivity of the control sample as 100. These results are shown in Table 4 below.

[Table] Exemplary compounds (1)

[Table] Reference polymer (1)
The samples of the present invention (Test Nos. 17 to 21) have a considerable amount of capri, but the comparative samples (Tests No. 22 to 21)
25) shows that the occurrence of fog is large. Also,
Precipitating agent (phthalic anhydride, phenyl isocyanate) used when creating the comparative sample 1 or 2
It was observed that the polymer used in the present invention can be applied to photographic elements without using any organic solvent. Therefore, it does not cause any environmental conservation problems.
Moreover, the method according to the present invention can be carried out in an extremely short time compared to the conventional desalination process (control sample) which required an extremely long time.

Claims (1)

[Scope of Claims] 1. A method for precipitating a physically ripened silver halide emulsion, in which the silver halide emulsion has a viscosity of
0.05 to 0.50 (however, the value is measured as a 1% solution in a 0.1 mol/aqueous sodium chloride solution at 30 ± 0.5°C using an Ubbelohde viscometer) having a repeating unit represented by the following general formula. A method for precipitation of silver halide emulsions, characterized by precipitation in the presence of a polymer. General formula [Formula] (In the formula, M represents a hydrogen atom, an alkali metal atom, or an ammonium atomic group. n is 1, 2 or 3.
shows. )