PURPOSE: To provide an excellent reactive plasticizer for rubber, composed mainly of a terminal blocked branched polymer obtained by polymerizing a polyene and blocking terminal hydroxyl group of the resultant branched polymer with silyl group, etc., having excellent compatibility with rubber, etc., and capable of improving the processability of unvulcanized rubber.
CONSTITUTION: The objective plasticizer is produced by polymerizing a polyene having hydroxyl group at the terminal preferably by cationic polymerization to obtain a polymer (abbreviated as branched polymer) having a branched polyene structure as the main chain, blocking the terminal hydroxyl group of the brached polymer with a group selected from silyl group, aryl group, allyl group and glycidyl group, and using the obtained terminal-blocked branched polymer having a molecular weight of 550W10,000 as a main component. The blocking of the terminal hydroxyl group can be carried out, for example in the case of blocking with silyl group, by diluting a mixture of branched polymer and a tertiary amine with toluene and adding a silylation agent such as trimethylchlorosilane dropwise to the solution.
NAKAGAWA KENSHO
KAGEYAMA KUNIO
AWANE TOMOHIRO
YOKOHAMA RUBBER CO LTD