Reversibly thermochromic compositions

US8119778B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Walter Fischer · Reinach, CH
• Abdel-Ilah Basbas · Basel, CH
• Martin Brunner · Pforzheim, DE
• Rolf Benz · Gachnang, CH
• Manuele Vitali · Bologna, IT

Key dates

• Filing date: Jun 20, 2007
• Grant date: Feb 21, 2012
• Expiry date: Aug 9, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K2211/1433
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A reversible thermochromic system comprising a) a compound of the formula (I) or a tautomer thereof (I) wherein R1 is C1-C18alkyl, C2-C18alkenyl, C3-C12cycloalkyl, C3-C12cycloalkyl substituted by 1, 2 or 3 C1-C4alkyl; or C7-C12phenylalkyl; R2 and R3 are hydrogen or R2 and R3 together form a group —CH═CH—CH═CH—; and R4 is hydrogen, —NO2, —SO2—R1 or (4-nitrophenyl)azo; and b) a compound containing a group of the formula (II).