Extraction resistant polyolefin stabilizer

An extraction resistant polymer composition which comprises:

• a major proportion of the recurring groups A of the formula ##STR4## and a minor proportion of the recurring groups B of the formula ##STR5## wherein X can be ##STR6## - S - or --S.sub.2 -;
• and wherein
• R.sub.1 and R.sub.2 is a branched alkyl, cycloalkyl, alkaryl or an aryl group of 3 to 20 carbon atoms, R.sub.3 is a sulfonic acid group - SO.sub.3 H or a salt thereof, R.sub.4 and R.sub.5 is hydrogen, or an alkyl, cycloalkyl, alkaryl or an aryl group of 1 to 20 carbon atoms;
• which polymer composition is prepared by reacting under acidic conditions
• A. a mixture of a major proportion of at least one phenol of the formula ##STR7## and a minor proportion of at least one phenol of the formula ##STR8## B. with at least about 0.7 moles of a compound selected from the group consisting of aldehydes, ketones, sulfur monochloride and sulfur dichloride per mole of total phenols in the mixture of A.