Processes for the preparation of squarylium dyes
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Aug 12, 1997
Issued Date -
N/A
app pub date -
Jun 6, 1995
filing date -
Nov 20, 1991
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
Squarylium compounds of the formula: ##STR1## (in which Q.sup.1 and Q.sup.2 are each a chromophoric group having an aromatic 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 acyl, aliphatic, cycloaliphatic, aromatic or heterocyclic group, subject to the proviso that one of R.sup.3 and R.sup.4 may be an amino or substituted amino 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 nitrogenous heterocyclic 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.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully