Process and composition for use in photographic materials containing hydroquihones
US5338644A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1992 |
| Grant date | Aug 16, 1994 |
| Priority date | — |
| Expiry date | Dec 23, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/52
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Hydroquinones form stable hydrogen-bonded complexes with N,N,N',N'-tetrasubstituted diamides of aromatic dicarboxylic acids in which two carboxyl groups are arranged para to one another on the same phenyl ring. These complexes are useful in rendering the hydroquinones more water-dispersible to assist their incorporation into photographic products. Also, the diamides may be incorporated into photographic products to reduce or eliminate various problems associated with hydroquinones, including migration of hydroquinones within the product during storage and the discoloration of images on storage due to oxidation of hydroquinone present in an image-receiving element of the photographic product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.