Method for producing expandable polystyrene

US7776244B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Franz-Josef Dietzen · Haßloch, DE
• Gerd Ehrmann · Deidesheim, DE
• Bernhard Schmied · Bischofswerda, DE
• Martin Laun · Mannheim, DE
• Klaus Hahn · Lampertheim, DE
• Joachim Ruch · Monsheim, DE
• Markus Allmendinger · Deggingen, DE
• Jan Holoch · Leimen, DE
• Achim Datko · Leimen, DE

Key dates

• Filing date: Jun 6, 2003
• Grant date: Aug 17, 2010
• Expiry date: Mar 31, 2026

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2325/04
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A process for the preparation of expandable styrene polymers having a molecular weight Mw of greater than 170,000 g/mol, which comprises conveying a blowing agent-containing styrene polymer melt having a temperature of at least 120° C. through a die plate with holes whose diameter at the die exit is at most 1.5 mm, and subsequently granulating the extrudate, and expandable styrene polymers (EPS) having a molecular weight Mw of more than 170,000 g/mol with 0.05 to 1.5% by weight of internal water.