Process for inhibiting foaming utilizing maleic ester copolymer based defoamers, and defoamed compositions

A dispersion in an aqueous medium comprising effective foam-inhibiting amount of a defoamer consisting of a mixture of a mineral oil and about 5 to about 50 percent by weight based upon the total weight of said mineral oil and said polymer of a mineral oil-soluble polymer of the formula:

• ##STR14## wherein X represents hydrogen, alkyl of 1 to about 30 carbon atoms, phenyl, OR', ##STR15## wherein R' is hydrogen or an alkyl group having 1 to about 30 carbon atoms;
• R" is an alkyl group of 1 to about 30 carbon atoms;
• R is hydrogen or an unsubstituted or substituted alkyl group having about 8 to about 30 carbon atoms and at least one R is said alkyl group;
• y is an integer of 1-5;
• the sum of m, n, and o units is such that the sum of m and o units represents a major proportion thereof and the mole percentage of m, n and o units is such that n and o are each 0 to 25, and m is 50 to 100.

A dispersion in an aqueous medium comprising an effective foam-inhibiting amount of a defoamer consisting of an effective amount of a surfactant to impart water dispersibility thereto, a mixture of a mineral oil, and about 5 to about 50 percent by weight based upon the total weight of said mineral oil and said polymer of a mineral oil-soluble polymer of the formula:

• ##STR16## wherein X represents hydrogen, alkyl of 1 to about 30 carbon atoms, phenyl, OR', ##STR17## wherein R' is hydrogen or an alkyl group having 1 to about 30 carbon atoms;
• R" is an alkyl group of 1 to about 30 carbon atoms;
• R is hydrogen or an unsubstituted or substituted alkyl group having about 8 to about 30carbon atoms and at least one R is said alkyl group;
• y is an integer of 1-5;
• the sum of m, n, and o units is such that the sum of m and o units represents a major proportion thereof and the mole percentage of m, n and o units is such that n and o are each 0 to 25, and m is 50 to 100.