Water-soluble defoaming agents

Claim 1

A water-soluble defoaming agent for use in high temperature dyeing operations consisting essentially of i. from 20 to 94% by weight of an organopolysiloxane-polyoxyalkylene copolymer represented by the general formula G a R b 1 SiO 4-a-b/2 where G is a polyoxyalkylene group represented by the general formula --R'--OR"--A 1 where R' is a divalent alkylene group having 1 to 10 carbon atoms, R" is a divalent alkylene group having 2 to 10 carbon atoms, A 1 is a hydroxy group or a monovalent organic group selected from the class consisting of monovalent hydrocarbon groups, alkoxy groups, acyl groups, acyloxy groups and isocyanate groups, and m is a positive number; R 1 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 3 carbon atoms and halogen-substituted derivatives thereof, and a and b each are positive numbers with the proviso that (a+b) = 1.9 to 2.1, the ratio of said polyoxyalkylene groups denoted by G to said organopolysiloxane-polyoxyalkylene copolymer being in the range of from 0.3 to 0.8 by weight, ii. from 5 to 50% by weight of a polyoxyalkyleneglycol derivative represented by the general formula R.sup.3 --OR.sup.2.sub.n A.sup.2 where R 2 is a divalent alkylene group having 2 to 10 carbon atoms, R 3 is a saturated or unsaturated monovalent hydrocarbon group having 2 to 20 carbon atoms, A 2 is a hydroxy group or a monovalent organic group selected from the class consisting of monovalent hydrocarbon groups, alkoxy groups, acyl groups, acyloxy groups, and isocyanate groups, and n is a positive number, and iii. from 1 to 30% by weight of a nonionic surface active agent having the polyoxyalkylene structure in its molecule and selected from the group consisting of polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene aryl ethers, polyoxyethylene alkaryl ethers, castor oil modified with polyoxyethylenes, and polyoxyethylene-polyoxypropylene ethers with higher alcohols.