Image dye-forming couplers and photographic elements containing them
US6071683A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1998 |
| Grant date | Jun 6, 2000 |
| Priority date | — |
| Expiry date | Aug 7, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/39216
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention relates to a silver halide photographic element comprising a dye-forming coupler of formula (I) ##STR1## wherein R.sup.1 is selected from an alkyl group, an aryl group, a 5-10 membered heterocyclic group containing one or more O, N or S atoms, each of which groups is unsubstituted or substituted, or a substituted amino group; PA1 R.sup.2 is an unsubstituted alkyl group having a secondary or tertiary carbon atom attached to the oxygen atom; PA1 X is hydrogen or a coupling-off group; and PA1 R.sup.3 is a substituent and n is 0 to 4; or PA1 wherein R.sup.2, as defined above, and an R.sup.3 substituent may together with the O atom form a 5-10 membered heterocyclic group which may contain one or more further heteroatoms selected from O, N and S, said group being unsubstituted or substituted; and PA1 wherein at least one of R.sup.1, R.sup.2 and R.sup.3 separately or in combination constitutes a ballast group, PA1 the couplers providing enhanced light stability together with acceptable dye hue in images produced from photographic materials containing them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.