Gasket material and method of producing the same

Claim 1

A METHOD OF PRODUCING COATED GASKET OR LIKE MATERIAL COMPRISING APPLYING A LIQUID BOND PROMOTING COATING TO A METAL SHEET SURFACE WHICH HAS BEEN TREATED BY A CONVERSION AGENT CONTAINING HEXAVALENT CHROMIUM IONS, SAID COATING CONTAINING A BUTADIENE ACRYLONITIRLE COPOLYMER AND A PHENOLIC RESIN IN SUBSTANTIALLY EQUAL PARTS BY WEIGHT CONSTITUTING THE SUBSTANTIAL BULK OF SOLIDS OF SAID COATING, DRYING SAID COATING, APPLYING TO THE COATED SURFACE A FURTHER LIQUID COATING CONTAINING A BUTADIENE ACRYLONITIRLE COPOLYMER, AND SIMULTANEOUSLY HEAT CURING SAID COATINGS TO BOND THE SAME TO ONE ANOTHER AND TO SAID TREATED BASE SURFACE, WHILE CONTINUOUSLY ADVANCING SAID SURFACE IN THE COATING AND CURING THEREOF, IN THE ABSENCE OF LOCALLY APPLIED PRESSURE IN THE CURING, SAID COPOLYMERS OF SAID BOND PROMOTING AND FURTHER COATINGS CONTAINING A MINIMUM OF ABOUT 39% OF ACRYLONITRILE MONOMER BY WEIGHT, SAID CURING BEING CARRIED OUT AT A SUFFICIENTLY HIGH TEMPERATURE AND FOR A SUFFICIENT TIME TO ENABLE THE BOND TO THE FINALLY COATED SURFACE TO WITHSTAND FAILURE AT TEMPERATURE UP TO 400*F.