POLYSILOXANE-POLYOXYETHYLENE-POLYOXYPROPYLENE-TRIBLOCKCOPOLYMERS AND DEFOAMER COMPOUNDS CONTAINING THEM

摘要

A polysiloxane-polyoxyethylene-polyoxypropylene tri-block copolymer of formula (I) where the ratio of x/y is 0.12-0.20 is claimed. R1 = 1-8 C alkyl; R2 = -(CH2)pO-; p = 2, 3 or 4; R3 = H or 1-4 C alkyl; n = 40-80; m = 3-10; x = 3-6; y = 20-30.