Polymethacrylate-polyalkene complexes - as viscosity index improvers, dispersants and antioxidants for lubricating oil

摘要

A complex (I) contains (1) a polymetha rylate of molecular wt. 4 x 104-106, and (2) a liquid polymer, with mol. wt. 200-10,000, of a 3-12C alkene-1. The ratio by wt. of (1):(2) is 4:1-2:3 (2:1). The polymethacrylate is obtd. by copolymerising (a) 1-10 wt.% of CH2=C(CH3)-CO-NH-A-NRR1, where R and R1 are 1-2C alkyl and A is 1-5C alkanediyl, (b) 15-30% of R2OOC-C(CH3)=CH2 where R2 is 1-6C alkyl, (c) 40-60% of R3OOC-C(CH3)=CH3 where R3 is 10-14C alkyl, and (d) 15-30% of R4OOC-C(CH3)=CH3, where R4 is 16-20C alkyl, in the presence of the liquid polyalkene. (I) is a viscosity index (VI) improver for lubricating oils esp. automatic transmission fluids and crankcase oils. (I) combines good VI improving properties with dispersant and antioxidant properties.