5-thio-substituted benzotriazole UV-absorbers
AssigneeCiba-Geigy Corporation
InventorsRoland A. E. Winter, Volker H. von Ahn, Tyler A. Stevenson, Mark S. Holt, Ramanathan Ravichandran
Life of this patent
Estimating the term…
Abstract
2-(2-Hydroxyphenyl)-2H-benzotriazole UV-absorbers substituted at the 5-position of the benzo ring by a thioether group exhibit enhanced absorption in the near visible range (over 350 nm) allowing said compounds to be particularly effective in protecting polymer systems which are prone to degradation caused by actinic irradiation with wavelengths over 350 nm.
Claims4
A compound of formula I, II or III ##STR9## wherein R.sub.1 is hydrogen, straight or branched chain alkyl of 1 to 24 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkyl of 7 to 15 carbon atoms,
- R.sub.2 is straight or branched chain alkyl of 1 to 24 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkyl of 7 to 15 carbon atoms;
- said alkyl substituted by one or more --OH, --OR.sub.4 or --NH.sub.2 groups where R.sub.4 is alkyl of 1 to 12 carbon atoms;
- n is 1;
- R.sub.5 is --OR.sub.6 or --NH.sub.2 ;
- R.sub.6 is hydrogen or alkyl of 1 to 24 carbon atoms;
- or said alkyl substituted by one or more --OH groups;
- or --OR.sub.6 is --(OCH.sub.2 CH.sub.2).sub.W OH or --(OCH.sub.2 CH.sub.2).sub.W OR.sub.21 where w is 1 to 12 and R.sub.21 is alkyl of 1 to 12 carbon atoms,
- R.sub.3 is alkyl of 8 to 20 carbon atoms, alkenyl of 3 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms or said aryl substituted by one or two alkyl of 1 to 4 carbon atoms, and
- T is --S--, --S--S-- or --S--E--S--,
- where E is alkylene of 2 to 12 carbon atoms, cycloalkylene of 5 to 12 carbon atoms, or alkylene interrupted or terminated by cyclohexylene of 8 to 12 carbon atoms, and
- with the proviso that, when R.sub.1 is sec-butyl and R.sub.2 is tert-butyl, R.sub.3 is not methyl.
Dependencies are inferred from the claim text.