发明授权
- 专利标题: Polymer composition for pipes
- 专利标题(中): 管道聚合物组成
-
申请号: US09832227申请日: 2001-04-10
-
公开(公告)号: US06441096B1公开(公告)日: 2002-08-27
- 发明人: Mats Bäckman , Eeva-Leena Heino , Solveig Johansson , Jussi Laurell , Arja Lehtinen , Jarmo Lindroos , Marja Ora , Elisabeth Ribarits , Teija Sihvonen , Jari {umlaut over (Aa)}rilä
- 申请人: Mats Bäckman , Eeva-Leena Heino , Solveig Johansson , Jussi Laurell , Arja Lehtinen , Jarmo Lindroos , Marja Ora , Elisabeth Ribarits , Teija Sihvonen , Jari {umlaut over (Aa)}rilä
- 优先权: SE9803501 19981014
- 主分类号: C08L2300
- 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.
公开/授权文献
- US20020045711A1 Polymer composition for pipes 公开/授权日:2002-04-18
信息查询