Photographic products and processes
US5244771A · kind A · utility
2Cited by
9References
54Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1991 |
| Grant date | Sep 14, 1993 |
| Priority date | — |
| Expiry date | Aug 20, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B11/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A novel class of bridged indicator dyes is disclosed which possess absorption in the infrared region of the electromagnetic spectrum. These bridged indicator dyes are useful as light-absorbing, pH-sensitive optical filter agents in diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes. These indicator dyes will also find utility in titrations and other analytical techniques and products where pH-sensitive indicator dyes are employed and absorption of infrared is useful.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.