A method for evaluating long-term durability of a resin for piping is provided. Unlike the conventional FNCT evaluation method requiring a long period of time, the method disclosed herein is capable of predicting long-term durability of a resin for piping in a short time, by a simple calculation using a content of tie molecules, an entanglement molecular weight (M.sub.e) and a content of ultrahigh molecular weight components. In addition, the olefinic polymer is configured to have a predetermined relationship in relation to the content of tie molecules, the entanglement molecular weight (M.sub.e) and the content of ultrahigh molecular weight components, whereby the polymer of the present application can be used in the manufacture of a heating pipe requiring excellent long-term durability.

A method for evaluating long-term durability of a resin for piping is provided. Unlike the conventional FNCT evaluation method requiring a long period of time, the method disclosed herein is capable of predicting long-term durability of a resin for piping in a short time, by a simple calculation using a content of tie molecules, an entanglement molecular weight (M.sub.e) and a content of ultrahigh molecular weight components. In addition, the olefinic polymer is configured to have a predetermined relationship in relation to the content of tie molecules, the entanglement molecular weight (M.sub.e) and the content of ultrahigh molecular weight components, whereby the polymer of the present application can be used in the manufacture of a heating pipe requiring excellent long-term durability.

A method for evaluating long-term durability of a resin for piping is provided. Unlike the conventional FNCT evaluation method requiring a long period of time, the method disclosed herein is capable of predicting long-term durability of a resin for piping in a short time, by a simple calculation using a content of tie molecules, an entanglement molecular weight (M.sub.e) and a content of ultrahigh molecular weight components. In addition, the olefinic polymer is configured to have a predetermined relationship in relation to the content of tie molecules, the entanglement molecular weight (M.sub.e) and the content of ultrahigh molecular weight components, whereby the polymer of the present application can be used in the manufacture of a heating pipe requiring excellent long-term durability.

Blown films, especially monolayer blown films, with an improved property profile, the blown films comprising at least 95.0 wt% of a specific heterophasic propylene copolymer (TERHECO).

Blown films, especially monolayer blown films, with an improved property profile, the blown films comprising at least 95.0 wt% of a specific heterophasic propylene copolymer (TERHECO).

The present invention provides a method for producing a catalyst for polymerization of an olefin, which suppresses a decrease in polymerization activity due to early deactivation of the active site after the catalyst has been formed, exhibits excellent catalyst activity at the time of polymerization of olefins, and can produce polymers of olefins, which are excellent in stereoregularity. The method for producing a catalyst for polymerization of an olefin includes contacting a solid catalyst component (A) containing magnesium, titanium, halogen and an internal electron-donating compound, and a specific organoaluminum compound (B) represented by the general formula (I), with each other, wherein at least one selected from the solid catalyst component (A) and the organoaluminum compound (B) is previously subjected to contact treatment with a hydrocarbon compound having one or more vinyl groups.

The present invention provides a method for producing a catalyst for polymerization of an olefin, which suppresses a decrease in polymerization activity due to early deactivation of the active site after the catalyst has been formed, exhibits excellent catalyst activity at the time of polymerization of olefins, and can produce polymers of olefins, which are excellent in stereoregularity. The method for producing a catalyst for polymerization of an olefin includes contacting a solid catalyst component (A) containing magnesium, titanium, halogen and an internal electron-donating compound, and a specific organoaluminum compound (B) represented by the general formula (I), with each other, wherein at least one selected from the solid catalyst component (A) and the organoaluminum compound (B) is previously subjected to contact treatment with a hydrocarbon compound having one or more vinyl groups.

A multimodal polyethylene composition having a lower molecular weight (LMW) ethylene homo or copolymer component (A) and a higher molecular weight ethylene copolymer component (B); wherein the lower molecular weight component comprises: (ai) a first fraction which comprises an ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; and (aii) a N second fraction which comprises a different ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; wherein the multimodal polymer composition has a density of 930 kg/m.sup.3 or more (ISO1183), such as 938 to 955 kg/m.sup.3, an MFR2 (ISO1133 at 190° C. and 2.16 kg load) in the range of 0.05 to 10 g/10 min, and a flexural modulus of up to 800 MPa, such as 300 to 800 MPa (ISO 178:2010).

A multimodal polyethylene composition having a lower molecular weight (LMW) ethylene homo or copolymer component (A) and a higher molecular weight ethylene copolymer component (B); wherein the lower molecular weight component comprises: (ai) a first fraction which comprises an ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; and (aii) a N second fraction which comprises a different ethylene homo or copolymer of ethylene and one or more C3-10 alpha olefins; wherein the multimodal polymer composition has a density of 930 kg/m.sup.3 or more (ISO1183), such as 938 to 955 kg/m.sup.3, an MFR2 (ISO1133 at 190° C. and 2.16 kg load) in the range of 0.05 to 10 g/10 min, and a flexural modulus of up to 800 MPa, such as 300 to 800 MPa (ISO 178:2010).

This invention relates to a self cleaning reactor and to a process for the oligomerization of ethylene that employs a self-cleaning reactor. The reactor includes a mass of inert, particulate cleaning bodies that are entrained by the liquid in the reactor and scour the internal surfaces of the reactor during normal operation. This scouring action reduces the level of fouling on the reactor surfaces. Foulant material (polyethylene) is removed from the process on a continuous basis but the cleaning bodies remain within the reactor.