Patent · US Expired

Method for producing block-shaped polymethacrylimide foamed materials

US6670405B1 · kind B1 · utility

4Cited by

3References

14Claims

0Family size

Assignee

ROEHM GMBH & CO. KG · DE

Inventors

Sabine Servaty · Großlittgen, DE
Werner Geyer · Heilbad Heiligenstadt, DE
Norbert Rau · Ober-Ramstadt, DE
Manfred Krieg · Darmstadt, DE

Key dates

Filing date	Oct 16, 2001
Grant date	Dec 30, 2003
Priority date	—
Expiry date	Oct 16, 2021

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08J2333/24
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

The invention relates to a method for producing block-shaped and plate-shaped polymethacrylimide foamed materials by copolymerizing methylacrylic acid and methylacryl nitrile, by subjecting the copolymerizate to a post-polymerization and cyclization in order to form polyimide, and by converting the same into a foamed material. The invention is characterized in that the copolymerization is carried out in the presence of a mixture containing at least three initiators with graduated half-life periods. The polymerization can be controlled especially well and yields polymerizate plates with thicknesses of up to 80 mm which can be easily foamed. The invention makes it possible to produce filling materials, especially plates and blocks containing electrically conductive particles.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.