DD204322A1 - METHOD FOR PRODUCING PHOTOGRAPHIC GELATINE-CONTAINING SILVER HALOGENIDE EMULSIONS - Google Patents

Abstract

The invention relates to the preparation of emulsions for color and black and white film materials. The object of the invention is to provide a method by which no more influence on the grain growth, deterioration of the chemical and spectral sensitization and formation of developable latentbildkeime occurs when using acidic gelatin with pH values greater than 6. This is accomplished by subjecting the silver halide to milling in the presence of one or more derivatives of digested gelatins. Derivatives of acid digested pig skin and / or bone gelatins, e.g. Phthaloyl and / or carbamoyl derivatives are used.

Description

Filmfabrik Wolfen Wolfen, 17.3-1982

PN 941 Li / Fi

Dr. Jäkel Int.Cl. ³ : G 03 C, 1/02

Prof. Dr. Pietsch Legutke

Process for the preparation of photographic gelatin-containing silver halide emulsions

Field of application of the invention

The invention relates to a process for the preparation of photographic gelatin-containing silver halide emulsions. Single- and multi-layered color and black-and-white film materials can be produced with these emulsions.

Characteristic of the known technical solutions

It is known that in the preparation of silver halide photographic emulsions by the conventional methods of fake-ash and flocking technology (James, Th. "The Theory of the Photographic Process", 5 * Ed Macmillan Publishing Co. Inc. New York and London (1977)), mainly alkaline-processed gelatins from bovine bone and hides with isoionic pH values below 6 are used worldwide. Bone gelatin, and especially pork rind, sour creams are of limited use, usually in coatings or backsheets (Croome, RJ, Clegg, FG "Photographic Gelatin" Focal Press London, New York 1965). These gelatins often have desensitizing properties in silver halide-containing photosensitive emulsions and suppress.bzw. delay the physical development.

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 Furthermore, negative effects on the growth of SiXberhalogenidkristalle and chemical and spectral sensitization are observed. Use in photosensitive emulsions is therefore associated with limitations, i. these gelatins must not be present in the reaction system during silver halide precipitation and may only be added in part after the completion of the precipitation or after fixing the photographic quality following the chemical ripening. In order to largely suppress the negative properties of these gelatins, it is also known to treat them with activated carbon or inorganic absorbers, to desalt them with ion exchangers or to inactivate them by treatment with oxidizing agents and salts. Also known are derivatization methods based on carboxymethylation of the gelatin by reaction with halogenated fatty acids, e.g. Bromoacetic acid or reaction with alkyl sultones based (DE-AS 1 244 573). This is intended to substantially reduce the delay in physical development, especially when using acid-digested pig skin gelatins.

However, with the illustrated methods, the above-mentioned deficiencies in influencing grain growth, deterioration of chemical and spectral sensitization, and formation of viable latent image nuclei when porcine dermal gelatinates are present during silver halide precipitation are not eliminated.

Object of the invention

The object of the invention is to expand the gelatin and gelatin raw material base for the photochemical industry.

Explanation of the essence of the invention

The negative properties associated with the use of acidified gelatins in photographic emulsions

could never be completely excluded with the previously known methods, so that their application is limited.

It is therefore an object of the invention to provide a process which avoids the deficiency in the use of acid-digested gelatins with isoionic pH values greater than 6 with regard to influencing grain growth, worsening the chemical and spectral sensitization and forming latent image nuclei capable of development ,

The object is achieved according to the invention by precipitation of the silver halide in the presence of one or more derivatives of acid-digested gelatins with pH values greater than 6 in the production of photographic gelatin-containing silver halide emulsions.

It is one of the particular advantages of the invention that the aforementioned negative effects of acid-digested gelatins, which occur especially during silver halide precipitation, are avoided if, according to the invention, the amino groups of these gelatins are blocked by suitable reactants.

For example, alkylating and acetylating agents, sulfonyl chlorides, divinyl sulfones, ketenes, anhydrides, benzoyl halides, substituted ureas and isoureas can react with the amino groups of the gelatin. The corresponding gelatin derivatives are prepared by synthesis methods described in the literature. Phthaloyl derivatives, or phenylcarbamoyl derivatives prepared in accordance with U3P 2 614, have proven to be particularly suitable.

These derivatives receptive acidic gelatins based on bovine bone or pig skins can also be employed during the silver halide precipitation, without ¹ that the shortcomings described, the emulsion influence the quality occur.

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The emulsions can be prepared by the washing or flocking technology. The flocculation can be carried out by pH reduction both after the silver halide precipitation and at a later stage of the process, whereby multiple flocculation processes are also possible. The method is applicable to cooking and ammonia emulsions of the positive, hegative, repro, and other emulsion types. The chemical sensitization is carried out in the usual way.

The invention will be explained in more detail in subsequent embodiments.

Outside Games

Various highly sensitive silver bromoiodide emulsions of the boiling and ammonia type are each optimally ripened and potted with a silver surface density of 10 g Ag / m on acetyl cellulose pad.

Exposure takes place behind a step wedge with blackening increase ~ f ~ 2 ; ¹ / 25th second, χ 4 100 W. development time: 4 minutes 40 ORWO fixing: 20 minutes ORWO 303 soaking: 20 minutes

In the tables, 1. the photographic properties of emulsions based on alkaline-digested and acid-digested gelatins are compared, 2. the inventively used derivatives of gelatins after .alkalic and acid digestion compared.

example 1

A high sensitivity silver bromide iodide emulsion of the ammonia type, having an iodide content of 2 mole% and an average grain size of 0.55 / μm, is prepared by the washing method.

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Gelatin used during the silver hai o β β η idf al treatment; 1. rel. Sensitivity r ^D min 1.alkali s chi chi. bone gelatin Second 100 3.4 0.12 2.sauer opened Pigskin 1. 80 2.0 0.13 3.Phthaloyl derivative of Second 108 3.4 0.11 4. Phthaloyl derivative of 104 3.5 0.13 5.Carbamoyl derivative of 106 3.4 0.12 6.Carbamoyl derivative of 106 3.5 0.12

Example 2

A highly sensitive silver emulsion type bromoiodide emulsion is prepared, having a iodide content of 1 mole 1% and an average grain size of 0.55 μm after the washing process.

Gelatin used during the silver halide precipitation rel. Sensitivity r D. min 1.alkisch geschi. bone gelatin 100 3.2 0.10 2.sauer opened Pigskin 75 1.95 0.11 3. Phthaloyl derivative of 1. 102 3.25 0.11. 4. Phthaloyl derivative of 2. 100 3.4 0.10 5.Carbamoyl derivative of 1. 104 3.3 0.10 6. Carbamoyl derivative of 2. 104 3.4 0.11 7. Phthaloyl derivative of an acidified Bone gelatin 100 · 3.25 0.10

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A highly sensitive silver-ammonia-type silverbroid-iodide emulsion, having an iodide content of 2 Mo 1% and an average grain size of 55.5 μm, is prepared according to the flocking technology.

Used gelatine rel. SENS L-X_ ^D min during the silver friendliness 3.1 halo ^ enidfellung 100 0.14 1.alkaline bone gelatin (Flocculation with flocking 1.85 medium) 65 0.11. 2.sauer opened Pigskin (Flocculation with flocking 3.1 mj-ttel) 105 3.0 0.10 3. Phthaloyl derivative of 1. 102 3.0 0.12 4. Phthaloyl derivative of 2. 100 0.12 5. Phthaloyl derivative of a sour bone gelatin

Example 4

A highly sensitive silver-bromide type emulsion of the boiling-emulsion type, having an iodide content of T Mo1% and an average grain size of 0.55 / μm, is prepared by the flocking technology.

Used gelatine rel. SENS r min while the silver friendliness 2.9 halogen idf precipitation 100 O ₉ 12 1.alkaline bone gelatin (Flocculation with flock - 7 - medium)

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Used gelatine rel. SENS r min while the silver friendliness 1.7 hai ο p ^ e η idf al ment 55 0.12 2.sauer insisted. Pigskin (Flocculation with flock t 3.1 medium) 104 3.1 0.12 3. Phthaloyl derivative of 1. 102 3.0 0.12 4. Phthaloyl derivative of 2. 104 0.11 5-phthaloyl derivative of a sour. kno chengelatine

It can be seen from the tables of Examples 1-4 that when the process according to the invention is used, the unfavorable properties of acid-digested gelatins with respect to alkaline-processed gelatins no longer occur.

Claims (3)

- ⁸ - 238889 6 invention claim 1. A process for preparing photographic gelatin-containing silver halide emulsions, characterized in that the precipitation of the silver halide is carried out in the presence of one or more derivatives of acidified gelatins with pH values greater than 6. 2. A process for the preparation of photographic gelatin-containing silver halide Emulaionen according to item 1, characterized in that derivatives of acid-digested pig skin and / or Knochengelatinen be used. 3. A process for the preparation of photographic gelatin-containing silver halide emulsions according to item 1 and 2, characterized in that phthaloyl and / or carbamoyl derivatives are used.