Copolymers

US3992310A · kind A · utility

Assignee

• The British Petroleum Company Limited · GB

Inventors

• Eric Forbes · Canton, US
• Ian G. Meldrum · Leatherhead, GB

Key dates

• Filing date: Mar 26, 1975
• Grant date: Nov 16, 1976
• Expiry date: Mar 26, 1995

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10N2040/08
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Copolymers useful as shear stable viscosity index improvers, are graft copolymers of polyisobutylene onto a polystyrene backbone. The copolymers are formed by the grafting of polyisobutylene onto the polystyrene backbone using Friedel Crafts catalysts.