Squarylium dyes, and processes and intermediates for the preparation thereof
US5227498A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1991 |
| Grant date | Jul 13, 1993 |
| Priority date | — |
| Expiry date | Nov 20, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41M5/392
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Squarylium compounds of the formula: ##STR1## (in which Q.sup.1 and Q.sup.2 are each a chromophoric group having an unsaturated system conjugated with the squarylium ring and such that in the compounds of formulae Q.sup.1 CH.sub.2 R.sup.1 and Q.sup.2 CH.sub.2 R.sup.2 the methylene hydrogens are active hydrogens, R.sup.1 and R.sup.2 are each independently a hydrogen atom or an aliphatic or cycloaliphatic group, and R.sup.3 and R.sup.4 are each independently a hydrogen atom, or an aliphatic, cycloaliphatic, aromatic or heterocyclic group, or one of R.sup.3 and R.sup.4 is a hydrogen atom and the other is an organosulfonyl group, or R.sup.3 and R.sup.4 together with the intervening nitrogen atom form a cycloaliphatic or aromatic ring) are useful as near infra-red absorbers. The presence of the amino group on the squarylium ring enables minor changes in absorption wavelength to be achieved by modifications of this group, and also allows functional groups to be incorporated into the dye without changing the chromophoric groups.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.