Alkylamides of hindered 3,5-dialkyl-4-hydroxybenzoic acids and use as
申请人:American Cyanamid Company
公开号:US03972927A1
公开(公告)日:1976-08-03
Compounds of the formula: ##SPC1## Wherein R.sub.1 and R.sub.2 are each branch-chain alkyl of 3 to 8 carbon atoms and R.sub.3 and R.sub.4 are each hydrogen, alkyl of 1 to 18 carbon atoms, or cycloalkyl of 5 or 6 carbon atoms are useful as light stabilizers in polyolefins. They may be prepared (a) by reacting the 3,5-di-alkyl-4-hydroxybenzoyl chloride with the appropriate amine in the presence of an acid acceptor or (b) by reacting the corresponding benzoic acid with the appropriate amine in the presence of a carbodiimide as dehydrating agent.