Process for preparing polyimide laminates

Abstract

Abstract THIS INVENTION IS DIRECTED TO A PROCESS FOR PREPARING REINFORCED RESIN LAMINATES OR PLASTIC COMPOSITES OF IMPROVED THERMAL STABILITY AND LOW VOID CONTENT WHICH COMPRISES IMPREGNATING A SUBSTANTIALLY FIBROUS MATERIAL E.G., GLASS FIBERS WITH AN EFFECTIVE AMOUNT OF AN ORGANIC SOLUTION OF A PRECURSOR OF AN IMIDE PREPOLYMER I.E., A POLYAMIDE-ACID. THE PRECURSOR-IMPREGNATED FIBROUS MATERIAL IS HEATED TO A TEMPERATURE RANGING UP TO ABOUT 300*F. TO REMOVE PART OF THE SOLVENT AND THEREBY OBTAIN AN INTERMEDIATE PRODUCT WHICH MAY BE CHARACTERIZED AS HAVING TACK AND DRAPE, SUBSEQUENTLY, THE POLYAMIDE-ACID IS IMIDIZED, IN SITU, TO THE PREPOLYMER AND CURED BY THE APPLICATION OF HEAT E.G., TEMPERATURES RANGING FROM ABOUT 250* F. TO 700*F. AND WITH PRESSURES RANGING UP TO ABOUT 1000 P.S.I. UNDRR THESE CONDITIONS, THE PREPOLYMER IS CURED TO FORM A REINFORCED THERMOST PLASTIC COMPOSITE. THE PRECURSOR OF THE IMIDE PREPOLYMER E.E., THE POLYAMIDE-ACID IS PREPARDD BY COREACTING APPROXIMATELY STOICHIOMETRIC AMOUNTS OF AT LEAST ONE POLYFUNCTIONAL AMINE WITH A MIXTURE OF ANHYDRIDES CONSISTING ESSENTIALLY OF AT LEAST ONE POLYFUNCTIONAL ANHYDRIDE AND MONOANHYDRIDE HAVING THE FORMULA: 1,3-DI(O=),3A,7A-DI(R-),R-1,3,3A,4,7,7A-HEXAHYDRO- 4,7-METHANOISOBENZOFURAN WHEREIN R IS SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND LOWER ALKYL RADICALS HAVING 1 TO 5 CARBON ATOMS PER MOLECULE.

Inventors

• 👤 Robert W Vaughan
• 👤 Hyman R Lubowitz

Bibliographic Details