Abstract: The present invention deals with coated pipes having a layer of multimodal polyethylene. The multimodal ethylene copolymer is a copolymer of ethylene with one or more alpha-olefin comonomers having from 4 to 10 carbon atoms and has a weight average molecular weight of from 70000 g/mol to 250000 g/mol, the ratio of the weight average molecular weight to the number average molecular weight, Mw/Mn, of from 15 to 50, a melt index MFR2 of from 0.05 g/10 min to 5 g/10 min, a melt index MFR5 of from 0.5 to 10 g/10 min and a density of from 930 kg/m to 955 kg/m3.

Abstract: The present invention deals with polymer compositions suitable for making pipes. The compositions comprise a multimodal copolymer of ethylene and one or more alpha-olefins having from 4 to 10 carbon atoms wherein the multimodal ethylene copolymer has a density of from 937 to 950 kg/m3, a melt index MFR5 of from 0.3 to 3.0 g/10 min, a melt index MFR2 of from 0.1 to 2.0 g/10 min and a shear thinning index SHI2.7/210 of from 2 to 30.

Abstract: Coated pipes have a layer of multimodal polyethylene. The multimodal ethylene copolymer is a copolymer of ethylene with one or more alpha-olefin comonomers having from 4 to 10 carbon atoms and has a weight average molecular weight of from 70000 g/mol to 250000 g/mol, the ratio of the weight average molecular weight to the number average molecular weight, Mw/Mn, of from 15 to 50, a melt index MFR2 of from 0.05 g/10 min to 5 g/10 min, a melt index MFR5 of from 0.5 to 10 g/10 min and a density of from 930 kg/m3 to 955 kg/m3.

Abstract: The present invention deals with polymer compositions suitable for making pipes. The compositions comprise a multimodal copolymer of ethylene and one or more alpha-olefins having from 4 to 10 carbon atoms wherein the multimodal ethylene copolymer has a density of from 937 to 950 kg/m3, a melt index MFR5 of from 0.3 to 3.0 g/10 min, a melt index MFR2 of from 0.1 to 2.0 g/10 min and a shear thinning index SHI2.7/210 of from 2 to 30.

Abstract: The present invention deals with polymer compositions suitable for making pipes. The compositions comprise a multimodal copolymer of ethylene and one or more alpha-olefins having from 4 to 10 carbon atoms wherein the multimodal ethylene copolymer has a density of from 937 to 950 kg/m3, a melt index MFR5 of from 0.3 to 3.0 g/10 min, a melt index MFR2 of from 0.1 to 2.0 g/10 min and a shear thinning index SHI2.7/210 of from 2 to 30.

Abstract: The present invention deals with coated pipes having a layer of multimodal polyethylene. The multimodal ethylene copolymer is a copolymer of ethylene with one or more alpha-olefin comonomers having from 4 to 10 carbon atoms and has a weight average molecular weight of from 70000 g/mol to 250000 g/mol, the ratio of the weight average molecular weight to the number average molecular weight, Mw/Mn, of from 15 to 50, a melt index MFR2 of from 0.05 g/10 min to 5 g/10 min, a melt index MFR5 of from 0.5 to 10 g/10 min and a density of from 930 kg/m to 955 kg/m3.

Abstract: The present invention deals with polymer compositions suitable for making pipes. The compositions comprise a multimodal copolymer of ethylene and one or more alpha-olefins having from 4 to 10 carbon atoms wherein the multimodal ethylene copolymer has a density of from 924 to 935 kg/m3, a melt index MFR5 of from 0.5 to 6.0 g/10 min, a melt index MFR2 of from 0.1 to 2.0 g/10 min and a shear thinning index SHI27/210 of from 2 to 50.

Abstract: The present invention deals with polymer compositions suitable for making pipes. The compositions comprise a multimodal copolymer of ethylene and one or more alpha-olefins having from 4 to 10 carbon atoms wherein the multimodal ethylene copolymer has a density of from 924 to 960 kg/m3, a melt index MFR5 of from 0.5 to 6.0 g/10 min, a melt index MFR2 of from 0.1 to 2.0 g/10 min and a shear thinning index SHI2.7/210 of from 2 to 50. The compositions further have a level of volatile compounds of at most 100 ppm by weight and/or a homogeneity rating of at most 3.

Abstract: The present invention deals with coated pipes having a layer of multimodal polyethylene. The multimodal ethylene copolymer is a copolymer of ethylene with one or more alpha-olefin comonomers having from 4 to 10 carbon atoms and has a weight average molecular weight of from 70000 g/mol to 250000 g/mol, the ratio of the weight average molecular weight to the number average molecular weight, Mw/Mn, of from 15 to 50, a melt index MFR2 of from 0.05 g/10 min to 5 g/10 min, a melt index MFR5 of from 0.5 to 10 g/10 min and a density of from 930 kg/m3 to 955 kg/m3. The pipes can be coated with high throughput and good production economy. The coatings have good mechanical properties.

Abstract: The present invention provides a method for tailoring the molecular weight distribution of a multimodal (e.g. bimodal) ethylene polymer having a lower molecular weight component and a higher molecular weight component comprising polymerising ethylene and optionally at least one further alpha olefin in at least two stages, wherein at least one stage is carried out in a slurry phase in the presence of a Ziegler Natta catalyst comprising an electron donor which is an ether.

Abstract: The present invention relates to a polyethylene composition comprising a base resin which comprises (a) an ethylene homo- or copolymer fraction (A); and (b) an ethylene homo- or copolymer fraction (B), wherein (i) fraction (A) has a lower weight average molecular weight than fraction (B); (ii) the base resin has a density of 932 to 938 kg/m3; (iii) the polyethylene composition has an MFR5 of 0.1 to 0.6 g/10 min; and (iv) the polyethylene composition has a shear stress ?2.7 kPa of 85 to 230 kPas. Furthermore, the present invention relates to an article, preferably a pipe comprising said composition and to the use of said composition for the production of an article, preferably a pipe.

Abstract: The present invention relates to a pipe or a supplementary pipe article comprising a polyethylene composition comprising a base resin which comprises (A) a first ethylene homopolymer fraction, and (B) a second ethylene homo- or copolymer fraction, wherein fraction (A) has a lower average molecular weight than fraction (B), and the composition further comprises (C) an inorganic mineral filler, wherein inorganic mineral filler (C) is present in the composition in an amount of 1 to 70 wt. %, and to the use of said composition for the production of a pipe or a supplementary pipe article.

Abstract: The present invention relates to a pipe or a supplementary pipe article comprising a polyethylene composition comprising a base resin which comprises (A) a first ethylene homo- or copolymer fraction, and (B) a second ethylene homo- or copolymer fraction, wherein fraction (A) has a lower average molecular weight than fraction (B), the base resin has a flexural modulus determined according to ISO 178 of 1000 MPa or higher, and the composition further comprises (C) an inorganic mineral filler, wherein inorganic mineral filler (C) is present in the composition in an amount of 1 to 70 wt. %, and to the use of said composition for the production of a pipe or a supplementary pipe article.

Abstract: The invention relates to novel multimodal polyethylene polymers comprising a low molecular weight fraction and a high molecular weight fraction, and having a MFR5 of greater than 0.10 g/10 min and less than or equal to 0.22 g/10 min, and a density of greater than equal to 952 kg/m3. The invention also relates to uses of the novel polymers in the production of polymeric articles, especially pipes.

Abstract: A pressureless pipe and polymer composition for making such a pipe as well as the use of the polymer composition for pressureless pipes and supplementary parts, are disclosed. The polymer composition is characterised in that the polymer comprises a multimodal ethylene polymer including a copolymer of ethylene and a C4-C10 &agr; -olefin comonomer; the ethylene polymer has a total density of 953-958 kg/m3 and a MFR5 of 0.2-2.0 g/10 min; the ethylene polymer has a modulus of elasticity, determined according to ISO 178 of 1300-1700 MPa; the ethylene polymer has a resistance to slow crack growth, determined according to ASTM F 1473 of more than 1.5 hrs.

Abstract: 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;747Pa) 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 SHI2 7/210=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).