| 摘要 |
PURPOSE:To obtain a viscosity index improver which has a low viscosity and is oxidation-resistant by dispersing an olefin polymer in a high concn. in a medium comprising an alkyl-substd. phneol, etc., using a specific dispersant. CONSTITUTION:An adduct (A) of an ethylenically unsatd. dicarboxylic acid with an olefin polymer is reacted with a compd. (B) having a group selected from the group consisting of amino, ketimine, hydroxyl, and isocyanate groups (e.g. ethylamine) to give a compd. comprising residues of components A and B bonded to each other through an amide group, an imide group, an ester group, etc. The resulting compd. is used as a dispersant for dispersing an olefin polymer in a high concn. in a medium which comprises an alkyl-substd. phenol and/or alkyl salycilate and does not dissolve or hardly dissolves the polymer, giving the objective improver. |
