Benzofuran dyes containing a coumarin nucleus
US4973694A · kind A · utility
1Cited by
9References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1989 |
| Grant date | Nov 27, 1990 |
| Priority date | — |
| Expiry date | Aug 17, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B23/105
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A 6-tertiary amino-2-(Z.dbd.CH--)benzofuran dye is disclosed, where Z represents the atoms providing an electron withdrawing group and a conjugated methine linkage completing a resonant dye chromophore including the 6-tertiary amino group as an electron donor and the electron withdrawing group as an electron acceptor. The dyes are formed by condensing a 6-tertiary amino-2-formylbenzofuran with an electron withdrawing dye nucleus precursor containing an active methyl or methylene site. The dyes exhibit bathocromically shifted absorption peaks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.