Photographic elements containing infrared filter dyes
US4876181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1988 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | Mar 10, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/832
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A dye useful for absorbing infrared radiation in photographic elements, having the structure: ##STR1## is disclosed. In this formula R.sub.1 and R.sub.2 each independently represents sulfoalkyl, carboxyalkyl, or sulfatoalkyl of from 3 to 6 carbon atoms, having at least 3 carbon atoms in the alkyl chain between the nitrogen atom of each Z ring and the sulfo or sulfato group, and at least 2 carbon atoms in the alkyl chain between the nitrogen atom of each Z ring and the carboxy group. R.sub.3 and R.sub.5 are each hydrogen or together represent the atoms necessary to complete 5- or 6-membered carbocyclic ring, and R.sub.4 represents hydrogen, alkyl of 1 to 4 carbon atoms, aryl, cyano, halogen, or ##STR2## where R.sub.6 and R.sub.7 each independently represents alkyl of from 1 to 6 carbon atoms or aryl, or together represent the non-metallic atoms necessary to form a 5- or 6-membered ring. X.sym. represents a cation. Z.sub.1 and Z.sub.2 each independently represent the atoms needed to complete an indole, naphthindole or benzindole nucleus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.