Abstract:
The present invention which provides antifoaming agents for the paper industry, based on oil-in-water emulsions, in which the oil phase accounts for from 5 to 50% by weight of the emulsion if the oil phase of the emulsions contains (a) an alcohol of not less than 12 carbon atoms, fatty esters of alcohols of not less than 22 carbon atoms and C1-C36-carboxylic acids, distillation residues which are obtainable in the preparation of alcohols having a relatively large number of carbon atoms by the oxo synthesis or by the Ziegler method and which may furthermore be alkoxylated, a mixture of the stated compounds and (b) optionally a fatty ester of a C12-C22-carboxylic acid with a monohydric to trihydric C1-C18-alcohol and, (c) optionally a hydrocarbon having a boiling point above 200° C. or a fatty acid of 12 to 22 carbon atoms, in combination with from 1 to 80% by weight of component (d) comprising (d1) polyglyceryl esters which are obtainable by not less than 20% esterification of a polyglycerol mixture of from 0 to 10% by weight of monoglycerol, from 15 to 40% by weight of diglycerol, from 30 to 55% by weight of triglycerol, from 10 to 25% by weight of tetraglycerol, from 0 to 15% by weight of pentaglycerol, from 0 to 10% by weight of hexaglycerol and from 0 to 5% by weight of polyglycerols having higher degrees of condensation with one or more fatty acids of 12 to 36 carbon atoms; and (d2) C18-C30 alkyl behenate. The antifoaming agents can be used for preventing foam in pulp cooking, in the beating of paper stock, in papermaking and in the dispersing of pigments for papermaking. Further, the anti-foaming agents can be used for preventing foam in paper stocks.