Branched block copolymers and their manufacture

US4167545A · kind A · utility

Assignee

• BASF SE

Inventors

• Gerhard Fahrbach
• Karl Gerberding · Monsheim, DE
• Erhard Seiler · Ludwigshafen, DE
• Dieter Stein

Key dates

• Filing date: Apr 14, 1978
• Grant date: Sep 11, 1979
• Expiry date: Apr 14, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G81/022
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Branched block copolymers of from 60 to 95 percent by weight of a monovinyl-aromatic compound and from 40 to 5 percent by weight of a conjugated diene. The branched block copolymers have a structure of the general formula EQU (A.sup.1 --A.sup.2 --B.fwdarw.A.sup.3).sub.n --X--(A.sup.3 .rarw.B--A.sup.2).sub.m where the A's are non-elastomeric polymer segments based on the monovinyl-aromatic compound, the B's are elastomeric polymer segments based on the conjugated diene, X is the radical of an at least trifunctional coupling agent and n and m are numbers. The branched block copolymers may be used for the manufacture of highly transparent impact-resistant shaped articles, especially packaging materials.