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US 4,127,586 AGranted
Light protection agents
AssigneeCiba-Geigy Corporation
InventorsJean Rody, Hansjorg Heller
Life of this patent
Estimating the term…
Abstract
New 2-(2'-hydroxyphenyl)-benzotriazoles are used for protecting light-sensitive organic materials. They are prepared by diazotization of a 2-nitroaniline, coupling of the resulting diazo compound with a phenol and reduction of the resulting 2-nitroazo compound.
Claims6
A compound of the formula ##STR14## in which (a) one of X.sub.1 and X.sub.2 denotes a secondary alkyl selected from the group consisting of isopropyl or secondary butyl, the other of X.sub.1 and X.sub.2 denotes secondary-butyl, tert. butyl, tert. amyl, tert. octyl, secondary-nonyl, tertiary. nonyl, 1-phenylethyl, cyclohexyl, or cyclooctyl
- (b) one of X.sub.1 and X.sub.2 denotes 1-phenylethyl, the other of X.sub.1 and X.sub.2 denotes methyl;
- and R.sub.1 denotes hydrogen or chloro.
Dependencies are inferred from the claim text.