Shear stable multirange oils having an improved viscosity index

US4822508A · kind A · utility

Assignee

• Rohm Co., Ltd. · JP

Inventors

• Horst Pennewiss · Darmstadt, DE
• Heinz Jost · Seeheim-Jugenheim, DE
• Helmut Knoell · Herbstein, DE

Key dates

• Filing date: Sep 19, 1988
• Grant date: Apr 18, 1989
• Expiry date: Sep 19, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10M2217/06
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Multirange lubricating oils having high shear stability comprising paraffinic oils as their base and containing, as an additive improving the viscosity index, a mixture of at least two different polymer species, each of said polymer species being composed of monomers selected from the group consisting of PA1 (a) esters of methacrylic acid and acrylic acid with linear alcohols having 6 to 15 carbon atoms, PA1 (b) esters of methacrylic acid and acrylic acid with linear alcohols having from 16 to 30 carbon atoms, PA1 (c) esters of methacrylic acid and acrylic acid with branched alcohols having from 6 to 40 carbon atoms, PA1 (d) esters of methacrylic acid and acrylic acid with alcohols having from 1 to 5 carbon atoms, and PA1 (e) other monomers, different from (a)-(d), susceptible to free-radical copolymerization, and containing functional groups in the molecule, monomer or monomers (a) being from 0 to 100 mole percent of said polymer species, monomer(s) (b) being from 0 to 10 mole percent, monomers (c), (d) and (e) combined being from 0 to 100 mole percent, and monomers (a) to (e) combined being 100 mole percent of said polymer species, said individual polymer species differing from o…