abstract |
An adduct of (A) a butadiene lower polymer or copolymer and (B) an alpha , beta -ethylenically unsaturated dicarboxylic acid compound is prepared by reaction in the presence of (C) a 2,5-di-tert-alkylhydroquinone compound of the formula <IMAGE> wherein R1, R2 and R3 each C1-8 alkyl groups.a |