| 摘要 |
1495850 Polymer grafting during extrusion KABEL-UNDMETALLWERKE GUTEHOFFNUNGSHUTTE AG 2 Dec 1975 [12 Dec 1974 1 July 1975] 49449/75 Heading B5A [Also in Division C3] Cross-linkable polymers, e.g. in the form of cable sheaths or other elongated articles, are produced by (1) grafting to the polymer an unsaturated hydrolysable silane compound at a temperature above 140‹ C. while mechanically working in a first extruder, (2) continuously de-gassing the product whilst still in the form of a warm moving mass, and (3) moulding the product in a second extruder without intermediate storage. The process may be effected either in apparatus comprising a first extruder affording a masticating/mixing chamber, then a vacuum de-gassing chamber, then a second extruder; or in apparatus comprising two extruders arranged in L-formation, in the first of which mechanical working and grafting is effected, and in the second of which de-gassing is effected and the product is extruded. The final moulded products, e.g. of polyethylene grafted with vinyltrimethoxysilane, are moisture-curable.
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