| abstract |
An oil-soluble polyester having a weight average molecular weight of 10,000 to 1 000,000, which is a polycondensate prepared by polycondensing the following ingredients (A), (B) and (C): (A) a divalent higher carboxylic acid ingredient, (B) a divalent alcohol ingredient comprising a glycol represented by the following formula:HO-CH2-CR1R2-CH2-OHwherein R1 and R2 represent a alkyl group, and the sum of carbon numbers in R1 and R2 is at least three, and (C) 0.1 to 15% by mole, based on the total of ingredients (A) and (B), of at least one multi-valent ingredient selected from a carboxylic acid with a valency of at least three and an alcohol with a valency of at least three. This oil-soluble polyester is useful as an additive for a lubricating oil. |