申请人:UNION CARBIDE CHEMICALS & PLASTICS TECHNOLOGY CORPORATION
公开号:EP0743161A2
公开(公告)日:1996-11-20
A process for the co-extrusion of an inner layer around a conductive medium and an outer layer around the inner layer comprising:
(i) introducing into an extruder adapted for profile co-extrusion, a conductive medium; an inner layer formulation comprising a homogeneous polyethylene having a polydispersity in the range of about 1.5 to about 3.5 and an essentially uniform comonomer distribution, and an organic peroxide; and an outer layer formulation comprising (a) a copolymer of ethylene and an unsaturated ester; (b) a polyethylene having a polydispersity greater than about 4.0 and a density of at least 0.916 gram per cubic centimeter, said polymer made by a high pressure process; or (c) a heterogeneous copolymer of ethylene and one or more alpha-olefins having a density of less than 0.916 gram per cubic centimeter, a melt index of at least about 4 grams per 10 minutes, and a polydispersity greater than about 4.0, and, optionally, an organic peroxide; and
(ii) co-extruding said formulations at a temperature no higher than about 160 degrees C.
一种围绕导电介质的内层和围绕内层的外层的共挤工艺,包括
(i) 将导电介质、内层配方和外层配方导入挤出机,内层配方包括均质聚乙烯(其聚 分散度在约 1.5 至约 3.5 之间,共聚单体分布基本均匀)和有机过氧化物;外层配方包 括:(a) 乙烯和不饱和酯的共聚物;(b) 聚乙烯(其聚分散度大于约 4.(c) 乙烯和一种或多种α-烯烃的异构共聚物,其密度小于每立方厘米 0.916 克,熔融指数至少约为每 10 分钟 4 克,多分散性大于约 4.0,以及可选的有机过氧化物;以及 (i) 通过高压工艺制成的聚合物。
(ii) 在不高于约 160 摄氏度的温度下共挤所述配方。