Improvements in frequency-stabilized metal-clad laminates

摘要

1,121,388. Laminates. GENERAL ELECTRIC CO. 10 Nov., 1966 [27 Dec., 1965], No. 50457/66. Heading B5N. A process of stabilizing the frequency response of a metal-clad polyolefin laminated structure comprises cycling the structure from room temperature into a uniform upper temperature just below the incipient melting point of the polyolefin, to uniform room temperature, to a uniform temperature of 0‹F. and to uniform room temperature until the frequency response remains essentially constant. The upper temperature is preferably 125‹ F. or 150‹ F. and the metal is preferably copper. The laminate is formed by application of heat and pressure to an assembly comprising the polyolefin sandwiched between two layers of the metal and the temperature cycling is effected immediately after formation of the laminate. Cycling is continued for about six cycles Suitable polyolefin materials are polyethylene, blends and no -polymers of olefins, such as ethylene with butadiene, isobutylene, propylene, butenes and pentenes, blends or co-polymers of an olefin with acrylonitrile, vinyl acetate and various acrylates.