Heat resistant reinforced composites of copolyimides
Abstract
Abstract Copolyimides are prepared from pyromellitic dianhydride (PMDA) or mixtures of pyromellitic dianhydride with 3,3'',4,4''benzophenone tetracarboxylic acid dianhydride (BTDA), and mixtures of 4,4''-methylenebis (phenyl isocyanate) (MDI) and toluene diisocyanate (TDI) (2,4-, or 2,6-isomer or mixtures thereof). The mixture of anhydrides is used in a molar percent ratio of PMDA to BTDA of 100 to 75/25 respectively. The mixture of isocyanates is used in a molar percent ratio from about 10/90 to 35/65 of MDI to TDI respectively. The copolyimides of the invention are soluble in their organic reaction solvents but retain their high thermal stability. The solubility allows for the facile preparation of films, laminates, coatings, fibers, and the like. The improvement in heat stability over previously known polyimides is achieved without any loss in solubility properties. The copolyimides can be used in the preparation of high temperature resistant polymer articles and in the various applications for which polyimides are known to be especially adapted.
Inventors
- 👤 Jr William J Farrissey
- 👤 Philip S Andrews
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
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