Siloxane-oxyalkylene copolymer surfactant compositions

Abstract

Siloxane-oxyalkylene copolymer surfactants in combination with alkyl esters of fatty acids are disclosed. Alkyl esters of fatty acids are represented by the general formula Z—COO—Y where Z is a saturated or unsaturated Calkyl or alkylene group and Y is typically a Calkyl, alkylene linear or branched group. The siloxane-oxyalkylene copolymer surfactants that are typically used with the fatty esters have the general formula MDD'M wherein M represents (CH)SiOor R(CH)SiO, D represents (CH)SiO, D′ represents (CH)RSiO, and the value of x+y is from 50 to 220, and the ratio x/y is from 5 to 15 inclusive. In the above formulae for M and D′, R is a polyether-containing substituent. The siloxane-oxyalkylene copolymer surfactants used in conjunction with the fatty ester contains a major fraction (60-80 wt. %) of siloxane-oxyalkylene with one pendant R typically defined as CHO(CHO)(CHO)R′ moieties having weight average molecular weights of from about 1400-2000 and wherein n is 1-4 and typically 3, the values of 'a' are in the range 12-22 and typically 16-20 and the values of 'b' are in the range of 12-22 and typically 16-20, R′ typically represent acyl group —C(O)CH. The surfactant of the invention also contains a minor fraction of a siloxane-oxyalkylene copolymer (6-10 wt. %) having two pendant R typically defined as CHO(CHO)(CHO)R′ moieties having average molecular weights of about 1000-3500 and wherein n is 1-4 and typically 3, the values of “a” are in the range 8-40 and typically 10-35 and the values of “b” are in the range of 8-40 and typically 10-35, R′ typically represent acyl group C(O)CH.