Patent · US Expired

Wash-off film containing synthetic amphoteric polymers

US4735887A · kind A · utility

10Cited by
7References
26Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 27, 1986
Grant dateApr 5, 1988
Priority date
Expiry dateJun 27, 2006

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S430/142
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

Sharper edges are obtained in silver halide wash-off films for tanning development when from 5 to 60% of the unhardened gelatin binder in one or more layers is replaced with a synthetic amphoteric polymer consisting essentially of at least one of each of three constituents: (a) carboxylic acid, (b) alkyl primary amine, and (c) secondary and/or tertiary amine, the amphoteric polymer having an isoelectric point of from 4 to 8.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.