Marking systems containing 3-aryl-3-heterylphthalides and 3,3-bis(heteryl)phthalides
US4189171A · kind A · utility
4Cited by
12References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1978 |
| Grant date | Feb 19, 1980 |
| Priority date | — |
| Expiry date | Jan 11, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/914
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
3-Aryl-3-indolylphthalides, 3-aryl-3-pyrrolylphthalides and 3-aryl-3-carbazolylphthalides prepared by interaction of the appropriate 2-(heteroaryl)carbonylbenzoic acid and the appropriate phenylamine, and 3,3-bis(indolyl)phthalides prepared by the interaction of the appropriate 2-(indolyl)carbonylbenzoic acid and the appropriate indole are useful as color formers in pressure-sensitive carbonless duplicating systems, thermal marking systems and hectographic copying systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.