Patent · US Expired

Closed cell polyimides

US4070312A · kind A · utility

27Cited by
4References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 27, 1975
Grant dateJan 24, 1978
Priority date
Expiry dateMay 27, 1995

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S521/918
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

Closed cell polyimide foams. Methods of making such foams from precursors derived from a benzophenonetetracarboxylic acid diester and a mixture of diamines in which the precursor is molded to shape and cured, hydrated, and heated until a porous, closed cell structure develops.

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