US2956880A - Preparation of washed emulsions and gelatin derivatives employed as peptizers in their preparation - Google Patents

Preparation of washed emulsions and gelatin derivatives employed as peptizers in their preparation Download PDF

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US2956880A
US2956880A US632422A US63242257A US2956880A US 2956880 A US2956880 A US 2956880A US 632422 A US632422 A US 632422A US 63242257 A US63242257 A US 63242257A US 2956880 A US2956880 A US 2956880A
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gelatin
parts
preparation
anhydride
heavy metal
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US632422A
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Jr John W Gates
Paul E Miller
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Eastman Kodak Co
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Eastman Kodak Co
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
    • G03C1/015—Apparatus or processes for the preparation of emulsions

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  • This invention relates to the preparation of new gelatin derivatives and the use of those derivatives in the coagulation washing of photographic emulsions in the presence of heavy metal salts.
  • emulsions are sometimes prepared with cadmium salts, such as cadmium chloride,
  • ver halide dispersion to a coagulated form upon adjustment of the pH thereof.
  • coagulation of the peptizer may occur at normal pH values.
  • a method for the coagulation washing of emulsions is described in U.S. application Serial No. 406,061 of Russell in which those salts are added to cause coagulation to occur.
  • This ver halide in the presence of the heavy metal salt to form a silver halide dispersion and therefore is not adapted for use in cases where the presence of the heavy metal salt is desirable in the silver halide formation operation.
  • One object of our invention is to provide a method of coagulation washing of silver halide dispersions in which heavy metal salts have been employed in their preparation. Another object of our invention is to provide gelatin derivatives which are useful in such a process. A still further object of our invention is to provide a procedure for preparing those gelatin derivatives. A still further object of our invention is to provide a coagulation method in which the coagulation occurs at a pH of 3.0-4.5. Other objects of our invention will appear herein.
  • a phthalated gelatin which contains 3-10 percent of a lower fatty acid radical therein such as acetyl, propionyl or the like, may be prepared by reacting phthalyl gelatin with lower fatty acid anhydride or by reacting upon gelatin simultaneously with phthalic anhydride and the lower fatty acid anhydride.
  • silver halide dispersions in which gelatin derivatives of that type are present are readily coagulated upon lowering of the pH thereof even though soluble heavy metal salts are present in the silver halide dispersion.
  • silver halide emulsions having a heavy metal salt content may be prepared by a coagulation method. The amount of phthalyl added to the gelatin may vary but the gelatin is reacted with five parts of phthalic Methods for the lation washing as described herein.
  • gelatinv derivative such as a phthalic anhydride derivative of
  • the gelatin has been reacted with phthalic anhydride in the amount of five :parts, seven parts or ten parts thereof per 100 parts of gelatin, the products obtained when used as peptiz'e'rs will result in coagulation of the silver halide dispersion when cadmium chloride is added at a usual PH;
  • a small percentage of lower fatty acid radical is present-therein, such as 5 percent, 8 percent or 10 percent acetyl, the dispersion does not coagulate when heavy metal salt is present therein. In the latter case, it is onlyrwhen the pH is reduced to a value within the range of. 3.0-4.5 that coagulation occurs.
  • the coagulate may be washed any number of times at the lowered pH and may be redispersed in water having a pH in the vicinity of 7.0 to form a washed emulp) sion having a contentof heavy metal salt therein.
  • heavy metal salts as coating addenda to emulsions just prior to coating.
  • there is danger of haze developing in the emulsion unless a considerable quanmethod, however, precludes the preparation of the siltity of gelatin was employed as the carrier for the silver halide.
  • a peptizer in accordance with our invention, any such haze eflect is avoided.
  • Example 1 100 parts of 5 percent phthalyl gelatin was plumped for 1 hour in 700 parts of water. The mass was stirred at 110 F. whereupon the gelatin derivative melted. The
  • Example 3 A gelatin derivative was prepared by the same procedure as described in Example 1 except that 600 parts of percent phthalyl gelatin was: employed in 2400"parts of water and this solution was treated with; l20 parts of acetic anhydride at a pH of 9.5. The rnass was then adjusted to a pH of 6.0: and the gelatin derivative obtained' was chilled, washed and dried in the usual-manner; a
  • the acetyl phthalyl gelatin did not interact with cadmium chloride solution at that pH' but coagulated when the pH was reduced'to 3.5.
  • Example 4 200 parts of: gelatin were plumped in 800: parts of' water and a. solution was obtained by heating to 110 F- with gentle agitation. The pH was adjusted to 9.5 with 20 percent aqueous sodium hydroxide and 20 parts of finely divided phthalic anhydride. was added. The pH was held at 9.5 by the occasional addition of alkali. At the completion of the reaction, 25 parts of acetic anhydride was added dropwise to the stirred solution while maintaining the pH' at 9.5. The pH was then adjusted to 6.0 with 6N-sulfuric acid and the solution was chilled, noodled and washed and the product was dried in a conventional manner. A gelatin derivative containing phthalyl and acetyl groups was obtained.
  • Example 5 Into a container with temperature control was put a solution with the following composition:
  • a filtered solution consisting of 200 parts. of silver nitrate and 2000 parts of water was placed.
  • the silver nitrate solution was placed. in a separating funnel at a temperature of 72 C. from which it was run, slowly, through a calibrated nozzle into the first container.
  • the contents of the latter were kept at a temperaturev of 70 C. and in constant motion by a mechanical stirrer during the precipitation and ripening
  • An emulsion was prepared in the absence of cadmium chloride using the same amount of phthalyl gelatin derivative, which derivative had'no acetyl therein.
  • the pH of the respective emulsions was lowered by the addition of sulfuric acid to the point at which the Silver halide dispersions coagulated, the mother liquor was decanted off in each case and the silver halide dispersion was washed twice at 20 C. There was then added to the mass sufiicient. gelatin in distilled water to form a satisfactory emulsion upon. stirring the mass at 40 C. Ammonia was added to bring the emulsion pH to 6.5 and stirring was continued until all of the solid matter was completely dispersed.
  • the two emulsions thus prepared were coated in the conventional manner upon suitable film base, exposed of a second using an Eastman 1B sensitometer with a 500-watt lamp at 3000 K. and developed 4 minutes in Kodak developer 13-19.
  • The. addition of cadmium chloride to the dispersion prepared using nonacetylated phthalyl- Frame Patent No. 2,525,753 is a typical example of the.
  • the amount of cadmium are present in the gelatin.
  • the amount of cadmium are present in the gelatin.
  • the. emulsion in accordance with our invention may be from A percent up to 4 percent based on the weight of the gelatin employed.
  • silvere halide dispersions which are coagulated in accordance with our invention are all. found. within the range of 3-45.
  • the acetyl phthalyl gelatins prepared in ac-- cordance with our invention are obtained either by acylating phthalyl gelatin or by reacting upon gelatin. with both phthalic anhydride and lower fatty acid. anhydride simultaneously'.
  • the gelatin which is employed is prefarably of photographic grade.
  • heavy metal salts which comprises reacting alkali metal halide With silver nitrate in an aqueous solution containing the soluble. salt of a polyvalent heavy metal and as the. peptizing agent therein gelatin lower alkanoate phthalate.
  • gelatin lower alkanoate phthalate which. is; the reaction product of a lower alkanoic acid, anhydride and phthalic anhydride with gelatin in anhydride and parts by weight of the gelatin.
  • a method of preparing washed silver halide photographic emulsion which comprises mixing in the presence of cadmium chloride a solution of silver nitrate and as.
  • a peptizer a solution of alkali metal halide with a gelatin acetate phthalate which is a reaction product of acetic acid anhydride and phthalic anhydride with gelatin in the ratio of 5 to 20 parts by weight of acetic acid anhydride, 3 to 10 parts by weight of phthalic anhydride and 100 parts by weight of gelatin, thereby forming a silver halide dispersion, adding acid to the dispersion to reduce the pH of themass to a. value within the pH range of 3-4.5

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Description

United States Patent 2,956,880 PREPARATION OF WASHED EMULSIONS. AND
Patented Oct. 18, 1960 ice anhydride per 100 parts of gelatin sufiicient phthalyl content is imparted thereto to be suitable for coagu- GELATIN DERIVATIVES ENIPLOYED AS PEP 5 TIZERS IN THEIR PREPARATION i John Gates, Jr., and Paul E. Miller, Rochester, N.Y., assignors to Eastman Kodak, Company, Rochester,. N.Y., a corporation of New Jersey 4 No Drawing. Filed ran. 4, 1957, Ser. No. 632,422-
2Claims. or. 96-94) This invention relates to the preparation of new gelatin derivatives and the use of those derivatives in the coagulation washing of photographic emulsions in the presence of heavy metal salts.
It is often desirable in the preparation of photographic emulsions that a small amount of a heavy metal salt be incorporated therein to impart desired characteristics to the emulsion. For instance, emulsions are sometimes prepared with cadmium salts, such as cadmium chloride,
therein which has the elfect of restricting the grain growth in the preparation of the silver halide and alsov acts as an anti-foggant in the photographic emulsion. The presence of other heavy metal salts such as iron, lanthanum, zinc, aluminum, nickel or chromium, may be desirable in emulsion preparations. coagulation washing of photographic emulsions have been described in U.S. Patents Nos. 2,614,928 and 2,- 614,931. In those methods gelatin derivatives are employed which make possible the conversion of the sil-.
ver halide dispersion to a coagulated form upon adjustment of the pH thereof. However, when heavy metal salts are present in the emulsion, coagulation of the peptizer may occur at normal pH values. A method for the coagulation washing of emulsions is described in U.S. application Serial No. 406,061 of Russell in which those salts are added to cause coagulation to occur. This ver halide in the presence of the heavy metal salt to form a silver halide dispersion and therefore is not adapted for use in cases where the presence of the heavy metal salt is desirable in the silver halide formation operation.
One object of our invention is to provide a method of coagulation washing of silver halide dispersions in which heavy metal salts have been employed in their preparation. Another object of our invention is to provide gelatin derivatives which are useful in such a process. A still further object of our invention is to provide a procedure for preparing those gelatin derivatives. A still further object of our invention is to provide a coagulation method in which the coagulation occurs at a pH of 3.0-4.5. Other objects of our invention will appear herein.
We have found that a phthalated gelatin which contains 3-10 percent of a lower fatty acid radical therein such as acetyl, propionyl or the like, may be prepared by reacting phthalyl gelatin with lower fatty acid anhydride or by reacting upon gelatin simultaneously with phthalic anhydride and the lower fatty acid anhydride. We have found that silver halide dispersions in which gelatin derivatives of that type are present, are readily coagulated upon lowering of the pH thereof even though soluble heavy metal salts are present in the silver halide dispersion. We have found that by our procedure washed silver halide emulsions having a heavy metal salt content may be prepared by a coagulation method. The amount of phthalyl added to the gelatin may vary but the gelatin is reacted with five parts of phthalic Methods for the lation washing as described herein.
.Whena gelatinv derivative, such as a phthalic anhydride derivative of; gelatin prepared by. reacting upon 100 parts. offgelatinwith five, parts of phthalic anhydride,
' is employed as the peptizer for silver halidein a dispersion containing cadmium chloride or the like, this dispersion coagulates at a pH between 7.0 and 4.5. If on the other hand a gelatin derivative containing both phthalyl andacetyl is employed and the silver halide is prepared invthe presence of cadmium chloride, no coagulation occurs within this pH range and to obtain coagulation it is necessary to reduce the pH such as to 3.0-4.5. .This holds true with gelatin derivatives having various phthalyl contents. For instance, if the gelatin has been reacted with phthalic anhydride in the amount of five :parts, seven parts or ten parts thereof per 100 parts of gelatin, the products obtained when used as peptiz'e'rs will result in coagulation of the silver halide dispersion when cadmium chloride is added at a usual PH; Whereas if a small percentage of lower fatty acid radical is present-therein, such as 5 percent, 8 percent or 10 percent acetyl, the dispersion does not coagulate when heavy metal salt is present therein. In the latter case, it is onlyrwhen the pH is reduced to a value within the range of. 3.0-4.5 that coagulation occurs.
The coagulate may be washed any number of times at the lowered pH and may be redispersed in water having a pH in the vicinity of 7.0 to form a washed emulp) sion having a contentof heavy metal salt therein. Sometimes it is desirable .to add heavy metal salts as coating addenda to emulsions just prior to coating. In those cases with the previously mentioned types of gelatin derivatives used as peptizers, there is danger of haze developing in the emulsion unless a considerable quanmethod, however, precludes the preparation of the siltity of gelatin was employed as the carrier for the silver halide. By using a peptizer in accordance with our invention, any such haze eflect is avoided.
The following examples illustrate the preparation of gelatin derivatives useful for preparing washed emulsions in accordance with our invention:
Example 1 100 parts of 5 percent phthalyl gelatin was plumped for 1 hour in 700 parts of water. The mass was stirred at 110 F. whereupon the gelatin derivative melted. The
pH was adjusted to 9.5 with 20 percent aqueous sodium hydroxide. Eighteen parts of propionic anhydride was added dropwise to the stirred mass over a 10-minute period while keeping the pH at 9.5. When the addi- "tion of propionic anhydride had been completed, the
pH was lowered to 6.0 with 6-N-sulfuric acid. The gelatin derivative thus obtained was chilled, washed and dried in the usual manner. A gelatin derivative having both propionyl and phthalyl groups was obtained. When a solution of this gelatin derivative was mixed with a cadmium chloride solution, no interaction took place, but a coagulate formed upon dropping the pH thereof to 3.8.
- Example 2 Example 3 A gelatin derivative was prepared by the same procedure as described in Example 1 except that 600 parts of percent phthalyl gelatin was: employed in 2400"parts of water and this solution was treated with; l20 parts of acetic anhydride at a pH of 9.5. The rnass was then adjusted to a pH of 6.0: and the gelatin derivative obtained' was chilled, washed and dried in the usual-manner; a
The acetyl phthalyl gelatin did not interact with cadmium chloride solution at that pH' but coagulated when the pH was reduced'to 3.5.
Example 4 200 parts of: gelatin were plumped in 800: parts of' water and a. solution was obtained by heating to 110 F- with gentle agitation. The pH was adjusted to 9.5 with 20 percent aqueous sodium hydroxide and 20 parts of finely divided phthalic anhydride. was added. The pH was held at 9.5 by the occasional addition of alkali. At the completion of the reaction, 25 parts of acetic anhydride was added dropwise to the stirred solution while maintaining the pH' at 9.5. The pH was then adjusted to 6.0 with 6N-sulfuric acid and the solution was chilled, noodled and washed and the product was dried in a conventional manner. A gelatin derivative containing phthalyl and acetyl groups was obtained.
Example 5 Example 6 Into a container with temperature control was put a solution with the following composition:
Parts Potassium bromide 165 Potassium iodide 5 Acetyl phthalyl gelatin prepared using 7 parts of phthalic anhydride per 100 of gelatin and having an acetyl content of 10% 5.0.5 Cadmium chloride 7.5
Water 1700 In another container a filtered solution consisting of 200 parts. of silver nitrate and 2000 parts of water was placed. The silver nitrate solution was placed. in a separating funnel at a temperature of 72 C. from which it was run, slowly, through a calibrated nozzle into the first container. The contents of the latter were kept at a temperaturev of 70 C. and in constant motion by a mechanical stirrer during the precipitation and ripening An emulsion was prepared in the absence of cadmium chloride using the same amount of phthalyl gelatin derivative, which derivative had'no acetyl therein. The pH of the respective emulsions was lowered by the addition of sulfuric acid to the point at which the Silver halide dispersions coagulated, the mother liquor was decanted off in each case and the silver halide dispersion was washed twice at 20 C. There was then added to the mass sufiicient. gelatin in distilled water to form a satisfactory emulsion upon. stirring the mass at 40 C. Ammonia was added to bring the emulsion pH to 6.5 and stirring was continued until all of the solid matter was completely dispersed.
The two emulsions thus prepared were coated in the conventional manner upon suitable film base, exposed of a second using an Eastman 1B sensitometer with a 500-watt lamp at 3000 K. and developed 4 minutes in Kodak developer 13-19. The emulsion inwhich the cadmiunr chloride was employed, had a similar speed and a higher gamma value than that in which .the cadmium chloride was omitted. The. addition of cadmium chloride to the dispersion prepared using nonacetylated phthalyl- Frame Patent No. 2,525,753 is a typical example of the.
preparation of the phthalylated gelatin. By this method. sufficient phthalyl is imparted to the. gelatin to impart acid-reversible characteristics thereto- The amount of fatty acid radical imparted to the gelatin to give the desired efiect in accordance with our invention is 3 per cent upto 10 percent or even more if esterifiable groups:
are present in the gelatin. The amount of cadmium.
chloride or other heavy metal salt which is present in.
the. emulsion in accordance with our invention may be from A percent up to 4 percent based on the weight of the gelatin employed. The coagulation values for the.
silvere halide dispersions which are coagulated in accordance with our invention are all. found. within the range of 3-45. The acetyl phthalyl gelatins prepared in ac-- cordance with our invention are obtained either by acylating phthalyl gelatin or by reacting upon gelatin. with both phthalic anhydride and lower fatty acid. anhydride simultaneously'. The gelatin which is employed is prefarably of photographic grade.
We claim:
1. A. method of preparing a silver halide dispersion.
adapted to be coagulation washed even in the presence of heavy metal salts which comprises reacting alkali metal halide With silver nitrate in an aqueous solution containing the soluble. salt of a polyvalent heavy metal and as the. peptizing agent therein gelatin lower alkanoate phthalate. which. is; the reaction product of a lower alkanoic acid, anhydride and phthalic anhydride with gelatin in anhydride and parts by weight of the gelatin.
2. A method of preparing washed silver halide photographic emulsion which comprises mixing in the presence of cadmium chloride a solution of silver nitrate and as.
a peptizer a solution of alkali metal halide with a gelatin acetate phthalate which is a reaction product of acetic acid anhydride and phthalic anhydride with gelatin in the ratio of 5 to 20 parts by weight of acetic acid anhydride, 3 to 10 parts by weight of phthalic anhydride and 100 parts by weight of gelatin, thereby forming a silver halide dispersion, adding acid to the dispersion to reduce the pH of themass to a. value within the pH range of 3-4.5
to coagulate the solids therein and subsequently dispersing the coagulate in a vehicle for the silver halide under non-coagulating conditions.
References Cited in the file of this patent UNITED STATES PATENTS 2,423,773 Hart et al. July 8, 1947 2,494,041 Frame Jan. 10., 1950 2,592,263 Frame Apr. 8, 1952' 2,614,928 Yutzy et al Oct. 21, 1952 2,614,929 Yutzy et a1. Oct. 21, 1952'

Claims (1)

1. A METHOD OF PREPARING A SILVER HALIDE DISPERSION ADAPTED TO BE COAGULATION WASHED EVEN IN THE PRESENCE OF HEAVY METAL SALTS WHICH COMPRISES REACTING ALKALI METAL HALIDE WITH SILVER NITRATE IN AN AQUEOUS SOLUTION CONTAINING THE SOLUBLE SALT OFR A POLYVALENT HEAVY METAL AND AS THE PEPTIZING AGENT THEREIN GELATIN LOWER ALKANOATE PHTHALATE WHICH IS THE REACTION PRODUCT OF A LOWER ALKANOIC ACID ANHYDRIDE AND PHTAHLIC ANHYDRIDE WITH GELATIN IN THE RATIO OF 5 TO 20 PARTS BY WEIGHT OF THE LOWER ALKANOIC ACID ANHYDRIDE, 3 TO 10 PARTS BY WEIGHT OF THE PHTHALIC ANHYDRIDE AND 100 PARTS BY WEIGHT OF THE GALATIN.
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3357832A (en) * 1963-05-06 1967-12-12 Gevaert Photo Prod Nv Water-soluble polytertiary amino compounds for decreasing the viscosity of photographc gelating-polymer solutions
US3486896A (en) * 1966-09-27 1969-12-30 Du Pont Process for eliminating stain and photographic elements therefor
US3837861A (en) * 1973-03-23 1974-09-24 Du Pont Gelatino-silver halide emulsions containing modified gelatin graft copolymers
US3884701A (en) * 1972-08-03 1975-05-20 Agfa Gevaert Nv Method of preparing silver halide emulsions
US4714758A (en) * 1985-04-10 1987-12-22 Koken Co., Ltd. Surfactant composed of acylated collagen or acylated gelatine and a production process thereof
WO2014030066A2 (en) 2012-08-22 2014-02-27 Bernitz Mats Nilsson Methods for identifying nucleic acid sequences

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2423773A (en) * 1942-06-24 1947-07-08 Iford Ltd Purification of gelatin
US2494041A (en) * 1947-08-13 1950-01-10 Eastman Kodak Co Derivatives obtained by reacting gelatin and furoyl halides
US2592263A (en) * 1947-08-13 1952-04-08 Eastman Kodak Co Method of reacting gelatin with naphthyl isocyanates and resulting products
US2614928A (en) * 1947-08-13 1952-10-21 Eastman Kodak Co Method of preparing photographic emulsions

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2423773A (en) * 1942-06-24 1947-07-08 Iford Ltd Purification of gelatin
US2494041A (en) * 1947-08-13 1950-01-10 Eastman Kodak Co Derivatives obtained by reacting gelatin and furoyl halides
US2592263A (en) * 1947-08-13 1952-04-08 Eastman Kodak Co Method of reacting gelatin with naphthyl isocyanates and resulting products
US2614928A (en) * 1947-08-13 1952-10-21 Eastman Kodak Co Method of preparing photographic emulsions
US2614929A (en) * 1947-08-13 1952-10-21 Eastman Kodak Co Method of preparing photographic emulsions

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3357832A (en) * 1963-05-06 1967-12-12 Gevaert Photo Prod Nv Water-soluble polytertiary amino compounds for decreasing the viscosity of photographc gelating-polymer solutions
US3486896A (en) * 1966-09-27 1969-12-30 Du Pont Process for eliminating stain and photographic elements therefor
US3884701A (en) * 1972-08-03 1975-05-20 Agfa Gevaert Nv Method of preparing silver halide emulsions
US3837861A (en) * 1973-03-23 1974-09-24 Du Pont Gelatino-silver halide emulsions containing modified gelatin graft copolymers
JPS49128989A (en) * 1973-03-23 1974-12-10
US4714758A (en) * 1985-04-10 1987-12-22 Koken Co., Ltd. Surfactant composed of acylated collagen or acylated gelatine and a production process thereof
WO2014030066A2 (en) 2012-08-22 2014-02-27 Bernitz Mats Nilsson Methods for identifying nucleic acid sequences

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