DISPERSING AGENT FOR MODIFYING DISPERSIVE ABILITY, METHOD FOR MODIFYING DISPERSIVE ABILITY, AND LUBRICATING FLUID Russian patent published in 2002 - IPC

FIELD: polymer dispersants. SUBSTANCE: invention relates to dispersing agents improving viscosity index, which contain polymers of conjugated dienes subjected to hydrogenation and functionalization. In particular, dispersing agents contain compositions including copolymer of intranuclearly substituted styrene and conjugated diene. Polymers are selectively hydrogenated to give polymers with strictly controlled residual content of aromatic unsaturation allowing functional groups to be introduced specifically. Invention also concerns lubricating fluids such as mineral and synthetic oils and, in addition, a method for modifying dispersive ability and/or viscosity characteristics of said lubricating fluids. The latter can likewise include carrying fluid in order to produce concentrates of dispersants. EFFECT: improved viscosity index of dispersants and lubricating fluids. 8 cl, 5 tbl, 27 ex