Verfahren zur Herstellung von Pfropfmischpolymeren

摘要

1336857 Graft copolymers MITSUBISHI PETROCHEMICAL CO Ltd 20 Nov 1970 [27 Nov 1969] 55273/70 Heading C3G In a process for producing a graft copolymer by subjecting a polymerization system comprising a base polymer substance and an ethylenically unsaturated monomer to radiation from at least one radiation source, the polymerization system and the radiation source are caused to undergo reciprocating movement relative to each other in such manner as to expose the polymerization system to at least two irradiation doses from each radiation source. The reciprocating movement may be produced by a conveyer belt conveying the polymerization system to be irradiated undergoing repetitions of a forward movement and a reverse movement in alternate sequence. Alternatively the reciprocating movement is produced by a belt conveyer mechanism conveying the polymerization system to be irradiated in a constant advancing direction, the entire belt conveyer mechanism being caused to undergo repetitions of alternate advancing and retreating movements. In this embodiment the advancing distances are greater than the retreating distances. The object to be irradiated may pass completely through the irradiation zone in both the advancing and retreating movements or in only one of the two movements. The irradiation source may be moved to realize the relative reciprocating movement. The base polymer may be a natural polymer such as wood or a synthetic polymer such as polypropylene. In one example a mixture of polypropylene and wood powder is employed. The grafting monomer may be methyl methacrylate or a styrene. The radiation source is preferably an electron accelerator.