Preparation of expandable granules, and the production of foams therefrom

US5091126A · kind A · utility

Assignee

• BASF SE

Inventors

• Heinz Weber · Uerdingen, DE
• Gerd Ehrmann · Deidesheim, DE
• Franz-Josef Dietzen · Haßloch, DE
• Eckhard Nintz · Ludwigshafen, DE
• Hans D. Zettler · Havelsee, DE

Key dates

• Filing date: Aug 3, 1990
• Grant date: Feb 25, 1992
• Expiry date: Aug 3, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2481/06
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A process for the preparation of expandable granules based on polyaryl ether sulfones and/or polyether imides, containing from 5 to 20% by weight of a physical blowing agent, the blowing agent and the polymers being mixed in an extruder and subsequently extruded directly into a medium at less than 40.degree. C., and a process for the production of foams from expandable granules based on polyaryl ether sulfones and/or polyether imides, containing from 5 to 20% by weight of a physical blowing agent, the granules being press molded at from 120.degree. to 250.degree. C. and at a pressure of from 5 to 30 bar to form a sheet, and the sheet being subsequently foamed by reducing the pressure, are described.