Color transfer photographic processes and products with indole phthalein filter dyes
US4615966A · kind A · utility
7Cited by
7References
29Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1986 |
| Grant date | Oct 7, 1986 |
| Priority date | — |
| Expiry date | Jan 21, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/48
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
This invention relates to diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes wherein enhanced opacification particularly, in the green region of the visible spectrum is achieved by employing a 7-sulfonamido/5- or 6-sulfamoyl indole phthalein as the light-absorbing, pH-sensitive optical filter agent for the shorter wavelength region of the visible spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.