Process of surface treating and laminating perfluorocarbon polymer films and laminated products made thereby

Claim 1

THE PROCESS OF LAMINATING TOGETHER A POLYIMIDE FILM HAVING A MOISTURE CONTENT BELOW ABOUT 1% BY WEIGHT AND A FILM OF A COPOLYMER OF TETRAFLUOROETHYLENE AND HEXAFLUOROPROPYLENE, THE LATTER FILM HAVING ONE SURFACE RENDERED CEMENTABLE BY SUBJECTING SAID SURFACE TO AN ELECTRICAL DISCHARGE AT SUBSTANTIALLY ATMOSPHERIC PRESSURE BETWEEN SPACED ELECTRODES, SAID ELECTRICAL DISCHARGE HAVING AN AVERAGE ENERGY LEVEL BELOW 15 ELECTRON VOLTS, IN AN ATMOSPHERE CONTAINING LESS THAN ABOUT 5% BY VOLUME OF THE VAPOR OF AN ORGANIC COMPOUND HAVING A VAPOR PRESSURE OF AT LEAST 0.25 MM. OF MERCURY AT 60*C. IN A GASEOUS CARRIER MEDIUM WHICH SUSTANINS THE ELECTRICAL DISCHARGE: SAID PROCESS COMPRISING BRINGING TOGETHER ONE SURFACE OF SAID POLYIMIDE FILM AND SAID CEMENTABLE SURFACE OF SAID COPOLYMER FILM, AND HOLDING THEM TOGETHER AT A TEMPERATURE IN THE RANGE OF 240* TO 280*C. AT A PRESSURE IN EXCESS OF ABOUT 10F POUNDS PER SQUARE INCH FOR AT LEAST 0.01 SECOND TO FORM A TWO-LAYER LAMINATE, AND SUBSEQUENTLY HEATING THE LAMINATE TO A TEMPERATURE IN THE RANGE OF 350*C. TO 500*C. FOR AT LEAST 1 SECOND.