POLYMER ADDITIVE IMPROVING INDEX OF VISCOSITY, METHOD FOR ITS PRODUCTION, MONOMER HAVING DISPERSION ACTION, CONCENTRATE AND LUBRICATING OIL Russian patent published in 1998 - IPC

FIELD: producing additive into lubricating oil. SUBSTANCE: copolymer additive is prepared by copolymerization of unsaturated esters having common formula where R¹ is H, alkyl, R_a is alkyl C₆-C₂₅ or mixture of C₆-C₂₅ alkyls; R_b= R_a, alkyl C₁-C₄; R_c is 2,2,6,6-tetramethyl-piperidine-4-ol or its mixture with radicals having 1 or 2 nitrogen atoms and 4-20 carbon atoms; mass ratio of esters having formula (I), (II) and (III) is not more 95%, not more 12 % and not more 8 % respectively. N-(3-hydroxypropyl)-N′-methyl piperazine metacrylate denoted as R_c in mentioned above formula (III) is described as monomer having dispersion action. EFFECT: improved index of viscosity of product. 14 cl, 4 tbl