Mitsui Petrochemical Industries, Ltd.

Osaka Gas Company Limited

Shinwa Sangyo Company, Ltd.

Mitsui Petrochemical Ind. Ltd.

Kazunori Mito

Hiroyuki Nishimura

Akio Nakashiba

Mikio Nakaoka

Toshio Shibabuchi

Fumio Nagatani

Naoshi Ishimaru

Masahiro Hirata

Tatsuo Saito

The improved electrofusion joint and header for supplying hot water that perform satisfactorily at elevated temperatures as evidenced by high heat resistance, that exhibit good sealing property and that can be handled efficiently in mounting and various other operations have a crosslinked thermoplastic resin layer and at least one joining portion which comprises a non-crosslinked thermoplastic resin layer that is formed a as an integral part of said crosslinked thermoplastic resin layer in the area where it contacts a tubular member to be joined, and a heating electric wire provided either within or on the outer or inner surface of said non-crosslinked thermoplastic resin layer. Such electrofusion joint and header are applicable to any part of a piping system for supplying hot water and they will withstand use for a prolonged period.

Electrofusion joint and hot water supply header using the same

The improved electrofusion joint and header for supplying hot water that perform satisfactorily at elevated temperatures as evidenced by high heat resistance, that exhibit good sealing property and that can be handled efficiently in mounting and various other operations have a crosslinked thermoplastic resin layer and at least one joining portion which comprises a non-crosslinked thermoplastic resin layer that is formed a as an integral part of the crosslinked thermoplastic resin layer in the area where it contacts a tubular member to be joined, and a heating electric wire provided either within or on the outer or inner surface of the non-crosslinked thermoplastic resin layer. Such electrofusion joint and header are applicable to any part of a piping system for supplying hot water and they will withstand use for a prolonged period.

A process for preparing a laminate by coating the surfaces of a metal substrate that has been treated with an anchor coating agent, with a modified olefin type resin and heat-adhering the olefin resin onto the surfaces of the metal substrate. The process of this invention is characterized by applying heat-treatment to the laminate at the time of adhesion or after the adhesion in the presence of a treating agent which consists of a compound prescribed in the general formulae (1) and (2). ##STR1## The laminate prepared by this process withstands deterioration of adhesion caused by aging, particularly in an atmosphere where water is present.

Process for preparing a laminate of metal and a polyolefin resin

An electrofusion joint used as a pipe joint for plastic pipes, wherein a coil electric heating wire is embedded inside and it is heated by application of an electric current after insertion of the plastic pipes to cause fusion/adhesion at the contact surface therebetween. The characteristic feature is to use one or more means of items (a) to (c) below to improve adhesion of the coil and the resin constituting the joint:

Electrofusion joint

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Kuga, Japan

Kazunori Mito