Particulate polystyrene containing blowing agent and having improved expandability

US4520135A · kind A · utility

Assignee

• BASF SE

Inventors

• Klaus Hahn · Lampertheim, DE
• Paul Wittmer · Landau, DE
• Isidoor De Grave · Monsheim, DE
• Rupert Schick · Schifferstadt, DE
• Adolf Echte · Ludwigshafen, DE

Key dates

• Filing date: Sep 13, 1983
• Grant date: May 28, 1985
• Expiry date: Sep 13, 2003

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2325/06
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Particulate polystyrene containing blowing agent and having improved expandability is based on polystyrene having a weight-average mean molecular weight of not more than from 130,000 to 180,000 and a molecular weight distribution curve in which the high molecular weight flank drops steeply. The expandable polystyrene particles are produced by polymerizing styrene in aqueous suspension in the presence of blowing agents and of chain transfer agents or styrene oligomers.