Polymer composition for pipes
    1.
    发明授权
    Polymer composition for pipes 有权
    管道聚合物组成

    公开(公告)号:US06441096B1

    公开(公告)日:2002-08-27

    申请号:US09832227

    申请日:2001-04-10

    IPC分类号: C08L2300

    摘要: A multimodal polymer composition for pipes is disclosed as well as a pipes made thereof. The polymer is a multimodal polyethylene with a density of 0.930-0.965 g/cm3, and a viscosity at a shear stress of 747 Pa (&eegr;747 Pa) of at least 650 Pa.s, said multimodal polyethylene comprising a low molecular weight (LMW) ethylene homopolymer fraction and a high molecular weight (HMW) ethylene copolymer fraction, said HMW fraction having a weight ratio of the LMW fraction to the HMW fraction of (35-55):(65-45). Preferably, the multimodal polyethylene has a viscosity at a shear stress of 2.7 kPa (&eegr;2.7 kPa) of 260-450 kPa.s; and a shear thinning index (SHI) defined as the ratio of the viscosities at shear stresses of 2.7 and 210 kPa, respectively, of SHI27/210=50-150, and a storage modulus (G′) at a loss modulus (G″) of 5 kPa, of G′5 kPa≧3000 Pa. The pipe is made of the multimodal polymer composition and withstands a stress of 8.0 MPa gauge during 50 years at 20° C. (MRS8.0). Preferably, the pipe has a rapid crack propagation (RCP) S4-value, determined according to ISO 13477:1997(E), of −5° C. or lower and a slow crack propagation resistance, determined according to ISO 13479:1997, of at least 500 hrs at 4.6 MPa/80° C. The polymer composition affords good non-sagging properties to pipe made thereof.

    摘要翻译: 公开了一种用于管道的多峰聚合物组合物以及由其制成的管。 聚合物是密度为0.930-0.965g / cm 3的多峰聚乙烯,剪切应力为747Pa(eta747Pa)下的粘度为至少650Pa.s,所述多峰聚乙烯包含低分子量(LMW) 乙烯均聚物部分和高分子量(HMW)乙烯共聚物部分,所述HMW部分具有LMW部分与HMW部分的重量比(35-55):(65-45)。 优选地,多峰聚乙烯在剪切应力为2.7kPa(eta2.7kPa)下的粘度为260-450kPa·s; 和剪切稀化指数(SHI),其分别定义为SHI27 / 210 = 50-150的剪切应力分别为2.7和210kPa的粘度比,以及损耗模量(G')下的储能模量(G'), ')为5kPa,G'5kPa> = 3000Pa。该管由多峰聚合物组合物制成,并且在20℃下在50年内耐受8.0MPa表压的应力(MRS8.0)。 优选地,管具有根据ISO 13477:1997(E)确定的-5℃或更低的快速裂纹扩展(RCP)S4值,并且根据ISO 13479:1997确定的缓慢的抗裂纹扩展性, 在4.6MPa / 80℃下至少500小时。聚合物组合物为其制成的管制得到良好的不下垂性能。