POLYORGANOSILOXANE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain a new polyorganosiloxane having a hindered phenol group bonded to a molecular terminal or a side chain through a carboxylic ester group and being desirable as an additive for modifying lubricants and resins. SOLUTION: This polyorganosiloxane is represented by formula I [wherein R is a monovalent hydrocarbon group; X is formula II (R<1> to R<4> are each a 1-6C alkyl or H, provided that at least either of R<1> and R<2> is an alkyl; R<5> to R<7> are each a 2-10C alkylene; and z is 0-50) or a hydrocarbon group; and m and n are each 0-500]. This is obtained by condensing a polyorganosiloxane represented by formula III (Y is -R<7> -(OR<6> )z OH or a monovalent hydrocarbon group) with a phenol-group-containing carboxylic acid (derivative) represented by formula IV (R<8> is hydroxyl, an alkoxyl or a halogen) [e.g. 3-(3'-5'-t- butylhydroxyphenyl)propionyl chloride].