Process for bonding an EPDM profile with PVC or wood, EPDM profile and welding solution to be used in the process

摘要

A process for bonding an EPDM profile to PVC or wood parts, comprises (a) coating at least part of the surface of the EPDM profile with a thin, unvulcanisable layer of a rubber mix based on copolymers of ethylene and propylene with or without tar-components (EPDM/EPM) with an ethylene content of at least 50 pts. wt., (b) vulcanising the EPDM profile at 180-220 deg. C and simultaneously subjecting the thin layer to a corresponding heat treatment, and (c) welding the thin layer to the PVC or wood thermally and/or by solvent or swell welding soln. Specifically (i) the EPDM profile is coated with a thin layer of a rubber mix based on sequence EPDM, emulsion PVC resin and the usual additives; (ii) the thermal welding is carried out by hot air, microwaves or infra red radiation; (iii) the EPDM profile is vulcanised in a salt bath by hot air or by UHF (iv) the EPDM profile and the thin rubber mix layer are formed by simultaneous extrusion; (v) the swell welding soln. is comprised of a solvent mixt. of sequence EPDM, a reinforcing resin such as a phenolic novolak resin and a formaldehyde donor such as hexamethylenetetramine; (vi) the swell welding soln. is pref. based on a chlorinated solvent, esp. a mixt. of THF and perchloroethylene, and may contain 5-15 wt.% of an isocyanate to improve the bond strength.