abstract |
Additives for oils prepared by polymerizing by an anionic process at least one vinyl aromatic compound and at least one conjugated diene in the presence of a solvent, followed by hydrogenation of the formed copolymer in the presence of the solvent, in which the solvent is a support oil having a viscosity within the range of 1 to 24 cst at 50 DEG C, a flash point of at least 120 DEG C and a pour point which is no greater than -10 DEG C. |