SHAPE-RECOVERABLE COMPOSITE MOLDED ITEM, PREPARATION THEREOF AND METHOD FOR USING IT

摘要

PURPOSE:To use a composite molded item for a bonding member, sealing member, etc., by covering with an electrically heating element made of a composite molded item and energizing electricity in the electrically heating body to recover the shape of a base body into an original shape and to fuse specified parts of the electrically heating element and the molded item. CONSTITUTION:A socket which is a composite molded item wherein an electrically heating element 2 and a base body 1 are integrated is obtd. by using a cylindrical electrically heating element 2 with a vol. intrinsic resistance at 25 deg.C of 5X10<2>OMEGA.cm or smaller as a core, feeding a reaction raw liq. contg. a norbornene monomer and a metathesis catalyst into a gap formed by enclosing by a mold and performing bulk ring-opening polymn. When two pipes made of a crosslinked polyethylene with an outer layer 41 covered by fusing a low density polyethylene having the same quality as that of the electrically heating element 2 are respectively inserted from each of both ends of the socket wherein the diameter has been enlarged at 80 deg.C and an alternating voltage is applied to each two electrode terminals 3 on both ends of the electrically heating element 2 from an electric source 5, the base body 1 is recovered to its original shape and the electrically heating element 2 and polyethylene on the surface of the pipe 4 are fused together and the pipe 4 and the socket are strongly bonded.