Stilbene dyestuffs and light-polarizing films or sheets containing stilbene

US5272259A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Uwe Claussen · Leverkusen, DE
• Friedrich W. Krock · Odenthal, DE

Key dates

• Filing date: May 26, 1992
• Grant date: Dec 21, 1993
• Expiry date: May 26, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K19/60
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Dyestuffs which in the form of the free acid conform to the formula ##STR1## in which X and Y independently represent --N.dbd.N--R, --CF.sub.3, --CONH.sub.2, --CONHR.sup.1, --CONR.sup.1 R.sup.2, --COOH, --COOR.sup.1, --CN, --NO.sub.2, --NH.sub.2, --NHR.sup.1, --NR.sup.1 R.sup.2, --OH, --OR.sup.1, --R.sup.1 CONH--, --O--CO--R.sup.1, halogen or a substituted or unsubstituted heterocyclic radical, provided that at least one of the radicals X or Y represents --N.dbd.N--R, in which PA1 R represents an aryl or heterocyclic radical, and PA1 R.sup.1 and R.sup.2 independently represent alkyl, cycloalkyl, aryl or aralkyl, which are uninterrupted or interrupted by O, S or both O and S, and in which furthermore the radicals mentioned for R, R.sup.1 and R.sup.2 are unsubstituted or substituted, the dyestuff contains a maximum of eight azo bridges, and with the exception of the dyestuff which, in the form of its free acid, conforms to the formula I wherein ##STR2## and light-polarizing films or sheets containing an organic polymer, preferably a vinyl alcohol homopolymer or copolymer, and dyestuff I.