Claims
- 1. A process for the preparation of a multilayer element having deferential hardness, said process comprising coating a support with a layer of unmodified gelatin and a layer of a modified gelatin and imbibing said layers with a hardener to harden said layers, wherein said modified gelatin has the formula: ##STR20## wherein Gel is a gelatin polypeptide, ##STR21## is a carbonyl group from a free carboxyl group in aspartic acid or a glutamic acid moiety in said polypeptide, and G is ##STR22## wherein each R is independently hydrogen or a primary or secondary alkyl group of one to about four carbon atoms, n is a positive integer having a value of one to about four, and T is hydrogen or ##STR23## said modified gelatin being further characterized by having from 1% to about 40% of the free carboxyl groups in aspartic and glutamic acid moieties in said polypeptide being substituted with G-groups;
- whereby said modified gelatin has a rate of reaction with a bis reactive olefin hardener which is faster than the reaction rate of said hardener with the corresponding unmodified gelatin not having substitution with G-groups.
- 2. Process of claim 1 wherein said hardener is a bis(vinylsulfonyl) hardener.
- 3. Process of claim 2 wherein said hardener is bis(vinylsulfonyl)methane.
- 4. A photographic element comprising layers of different hardness comprising a support, and on said support a layer of hardened unmodified gelatin and another layer of hardened modified gelatin, of claim 3.
Parent Case Info
This is a divisional of application Ser. No. 540,424, filed Jun. 18, 1990, now issued as U.S. Pat. No. 5,219,992.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2101758 |
Jan 1983 |
GBX |
Non-Patent Literature Citations (1)
Entry |
James, T. H., "The Theory of the Photographic Process", Fourth Edition, pp. 77-87, Macmillan Publishing Co., Inc., 1977. |
Divisions (1)
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Number |
Date |
Country |
Parent |
540424 |
Jun 1990 |
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