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Publication numberUS2725305 A
Publication typeGrant
Publication dateNov 29, 1955
Filing dateJan 2, 1952
Priority dateJan 2, 1952
Publication numberUS 2725305 A, US 2725305A, US-A-2725305, US2725305 A, US2725305A
InventorsAllen Charles F H, Byers Jr John R
Original AssigneeEastman Kodak Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hardening gelatin emulsions and gelatin solutions
US 2725305 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

HARDENING GELATIN EMULSIONS AND GELATIN SOLUTIONS 7 7 No Drawing. Application January 2, 1952, Serial No. 264,676

9 Claims. (Cl. 117-34) This invention relates to the hardening of gelatin, either in the form of an emulsion layer in photographic films, plates or papers, or when applied in the form of a solution, as a coating for paper or other similar material by means of a cyclic 1,2-diketone.

It is common practice in the use of photographic emulsions to incorporate something therein to overcome the tendency of the gelatin constituent to melt or to swell during its processing, particularly at high temperatures. Some of the hardening agents which have been employed for this purpose are formaldehyde, diacetyl, mucochloric acid, glyoxal and the like. None of these materials has met all the demands which have been put upon them for this purpose, especially in photographic uses.

One object of our invention is to provide a method for hardening gelatin layers. Another object of our invention is to provide a method of hardening gelatin layers which overcomes some of the difiiculties encountered in the use of known hardening agents and to provide a method whereby gelatin emulsions may be given a satisfactory degree of hardening. A further object of our invention is to provide photographic emulsions which will resist relatively elevated temperatures without melting, and which will do so without objectionable fogging or desensitizing. A still further object of our invention is to provide gelatin layers which will be less subject to the phenomenon known as after-hardening. Other objects of our invention will appear herein.

nited States Patent We have found that certain cyclic 1,2-diketones are particularly effective when incorporated in gelatin solutions in rendering the gelatin layers obtained therefrom resistant to elevated temperatures and without undue swelling. We have found that, of the cyclic 1,2-diketones, the following are particularly useful for hardening purposes: cyclohexane-LZ-dione, cyclopentane-LZ-dione and 3-chlorocyclopentane-l,2-dione. We have found that hardening can be accomplished under the proper conditions with as little as A of a gram of the diketone per liter of gelatin solution, although often in actual use larger quantities of the hardener are desirable. Although these hardeners will be employed in most cases within the range of .255%, based on the weight of the gelatin in the emulsion, these limits are merely illustrative, and the proportion of hardener may be varied within wide limits and still be effective in imparting resistance to the gelatin coating.

Our method is carried out by incorporating the cyclic diketone in an aqueous solution of the gelatin in the proportion desired, and then coating out the solution upon the support therefor, such as a photographic film base, paper, cloth or any other surface to which the gelatin layer will adhere. These diketones do not increase the viscosity of gelatin solutions on holding them liquid prior to coating; this is an advantage over hardeners such as alums which tend to change the viscosity with time, making it much more diflicult to secure a uniform coating. The hardening occurs during the drying of the coating. The effectiveness of the hardening may be increased by subr lC Example 1 To 100 milliliters of a gelatin-silver bromide photographic emulsion containing about 7 grams of gelatin, 0.05 gram of cyclopentane-1,2-dione was added, and the emulsion was applied as a coating on glass plates. The emulsion layer was dried and was then incubated at 100 F., 78% relative humidity, for about 96 hours. A plate from this group and a plate having a check coating thereon prepared like the above but without the hardener, and incubated similarly, were tested for hardening by processing with a photographic solution at F. for 5 minutes. These plates were thereupon transferred to 0.5% acetic acid and held 10 minutes, then washed in running water, all of the operations being at 85 F. It was found that the controlled coating melted badly, leaving one edge very thin, but the emulsion coating in which the diketone had been incorporated showed no visible signs of melting.

Example 2 had not been employed.

We claim: 1. A method of preparing hardened gelatin coatings which comprises incorporating in an aqueous solution of gelatin containing 0.255%, based on the weight of the gelatin, of a cyclic 1,2-diketone selected from the group consisting of cyclohexane-1,2-dione, cyclopentane-1,2- dione and 3-chlorocyclopentane-1,2-dione, applying the gelatin solution in the form of a thin layer to a surface, and then drying the gelatin layer.

2. A method of preparing a hardened gelatin coating which comprises adding to an aqueous solution of gelatin 0.255%, based on the Weight of the gelatin, of a cyclic 1,2-diketone selected from the group consisting of cyclohexane-l,2-dione, cyclopentane-l,2-dione and 3-chlorocyclopentane-1,2-dione, applying the solution in the form of a thin layer onto paper, and subsequently drying the coating thus applied.

3. A method of preparing a hardened gelatin coating which comprises adding to an aqueous solution of gelatin 0.255%, based on the weight of the gelatin, of a cyclic 1,2-diketone selected from the group consisting of cyclohexane-l,2-dione, cyclopentane-l,2-dione and 3-chlorocyclopentane-l,2-dione, applying the solution in the form of a thin layer onto photographic film base, and subsequently drying the coating thus applied.

4. A method of preparing a hardened gelatin-silver halide photographic emulsion coating which comprises adding to the emulsion while in fluid form 0.25-5 based on the weight of the gelatin, of cyclopentane-1,2-dione, applying the emulsion in the form of a thin layer onto a support therefor, and drying the emulsion layer.

5. A method of preparing a hardened gelatin coating which comprises adding to an aqueous solution of gelatin 0.25-5%, based on the weight of the gelatin, of a cyclic 1,2-diketone selected from the group consisting of cyclohexane-1,2-dione, cyclopentane-1,2-dione and 3-chloro- Cyclopentane-LZ-dione, applying the gelatin solution in g the form of a thin layer to a surface, drying the gelatin layer and subjecting that layer to a temperature of 100 F. 6. A composition comprising gelatin containing therein 0.254% based on the .weight'of the gelatin of acyclic 1,2-diketone selected from the group consisting of cyclohexane-1,2-dione, cyclopentane-1,2-dione and 3-ch1orocyc1opentane-1,2-dione.

7. Gelatin containing 0.255% dione. V

8. Gelatin containing O.255% of cyclopentane-1,2- dione. t

of cyclohexane-1,2-

4 9. Gelatin containing 0.255% pentane-1,2-dione.

of 3-chlorocyc1o- 1,851,166 Kienninger Mar. 29, 1932 2,071,559 Morgan Feb. 23, 1937 2,169,513 Brunken Aug. 15, 1939 2,356,477 Staud et a1. Aug. 22, 1944 2,476,240 Famulener July 12, 1949 2,534,326 Weaver Dec. 19, 1950

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1851166 *Apr 1, 1927Mar 29, 1932Technicolor Motion PictureMethod of effecting delayed hardening of films and resulting product
US2071559 *May 27, 1936Feb 23, 1937Sylvania Ind CorpArticle of manufacture
US2169513 *Jul 16, 1937Aug 15, 1939Agfa Ansco CorpProcess for hardening albuminous substances
US2356477 *Mar 25, 1941Aug 22, 1944Eastman Kodak CoHardeners for photographic processing solutions
US2476240 *Sep 17, 1943Jul 12, 1949Gen Aniline & Film CorpManufacture of photographic film base
US2534326 *Nov 27, 1946Dec 19, 1950Du PontProcess of manufacturing photographic elements
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2895827 *Oct 24, 1956Jul 21, 1959Eastman Kodak CoPhotographic paper base
US2983607 *Jan 26, 1959May 9, 1961Eastman Kodak CoTetramethylolcyclohexanol treatment to trevent popping and fading of transparencies and fading of color prints
US3061453 *Aug 3, 1959Oct 30, 1962Polaroid CorpProcess for incorporating photographic reagents in a photographic element using a common solvent and a preferential solvent
US3418132 *Jun 1, 1965Dec 24, 1968Eastman Kodak CoAldehyde gelatin hardening composition with carbocyclic diones
US3888681 *Aug 16, 1972Jun 10, 1975Fuji Photo Film Co LtdProcess for the rapid hardening of gelatin
US5422235 *Dec 18, 1992Jun 6, 1995Eastman Kodak CompanyProcess for manufacturing photographic paper
US7208257Jun 25, 2004Apr 24, 2007Xerox CorporationElectron beam curable toners and processes thereof
US7862970May 13, 2005Jan 4, 2011Xerox Corporationsuch as poly-diisopropylaminoethyl methacrylate-methyl methacrylate; including polymeric latex and colorant, and amino-containing polymer particles dispersed on external surface of particles; electrography; developers; electrostatics
Classifications
U.S. Classification430/538, 430/621, 106/156.3
International ClassificationG03C1/30
Cooperative ClassificationG03C1/30
European ClassificationG03C1/30