The present invention relates to a process for producing alpha-olefin polymers in a multistage polymerization process which includes at least two gas phase polymerization reactors, wherein unreacted gas withdrawn from the second gas phase polymerization reactor is compressed in a compressor and said compressed gas is fed via a conveying gas line into an outlet between a first outlet vessel downstream of the first gas phase polymerization reactor and said second gas phase polymerisation reactor. Such a process can alleviate problems of malfunction, disturbances or plugging of the transfer lines and enables higher productivity and considerable saving of energy and equipment cost. Moreover, the production of alpha-olefin polymers with varying and tailored properties is possible.

The present invention relates to a process for producing alpha-olefin polymers in a multistage polymerization process which includes at least two gas phase polymerization reactors, wherein unreacted gas withdrawn from the second gas phase polymerization reactor is compressed in a compressor and said compressed gas is fed via a conveying gas line into an outlet between a first outlet vessel downstream of the first gas phase polymerization reactor and said second gas phase polymerisation reactor. Such a process can alleviate problems of malfunction, disturbances or plugging of the transfer lines and enables higher productivity and considerable saving of energy and equipment cost. Moreover, the production of alpha-olefin polymers with varying and tailored properties is possible.

Blown films, especially monolayer blown films, of high stiffness, the blown films comprising at least 95.0 wt % of a specific propylene-1-butene random copolymer.

Blown films, especially monolayer blown films, of high stiffness, the blown films comprising at least 95.0 wt % of a specific propylene-1-butene random copolymer.

A heterophasic propylene polymeric material comprising a propylene-based polymer A, a propylene-based polymer B, and a propylene copolymer C, wherein the polymer A contains 80 mass % or more of monomer units derived from propylene and has a limiting viscosity of 2.0 dL/g or less, the polymer B contains 80 mass % or more of monomer units derived from propylene and has a limiting viscosity of 2.1-4.9 dL/g, the copolymer C contains monomer units derived from propylene and 30-55 mass % of monomer units derived from ethylene or the like and has a limiting viscosity of 1.5-4.5 dL/g, and the polymer A, the polymer B, and the copolymer C are respectively contained in ratios of 50-75 mass %, 5-20 mass %, and 5-40 mass %.

A heterophasic propylene polymeric material comprising a propylene-based polymer A, a propylene-based polymer B, and a propylene copolymer C, wherein the polymer A contains 80 mass % or more of monomer units derived from propylene and has a limiting viscosity of 2.0 dL/g or less, the polymer B contains 80 mass % or more of monomer units derived from propylene and has a limiting viscosity of 2.1-4.9 dL/g, the copolymer C contains monomer units derived from propylene and 30-55 mass % of monomer units derived from ethylene or the like and has a limiting viscosity of 1.5-4.5 dL/g, and the polymer A, the polymer B, and the copolymer C are respectively contained in ratios of 50-75 mass %, 5-20 mass %, and 5-40 mass %.

The present invention relates to a multimodal ethylene copolymer composition having a density of 920 to 949 kg/m.sup.3 and a flexural modulus, wherein said flexural modulus is following the equation: Flexural modulus [MPa]<21.35.Math.density [kg/m3]−19585 [1]. The multimodal ethylene copolymer composition according to the invention can be used in a highly flexible cable jacket, preferably a power cable jacket.

The present invention relates to a multimodal ethylene copolymer composition having a density of 920 to 949 kg/m.sup.3 and a flexural modulus, wherein said flexural modulus is following the equation: Flexural modulus [MPa]<21.35.Math.density [kg/m3]−19585 [1]. The multimodal ethylene copolymer composition according to the invention can be used in a highly flexible cable jacket, preferably a power cable jacket.

The present disclosure relates to a linear low-density polyethylene copolymer and a preparation method thereof. The linear low-density polyethylene copolymer has a long-chain branching (LCB) distribution similar to that of general metallocene polyethylene (mPE) and has good mechanical properties such as processability and toughness. Thus, the linear low-density polyethylene copolymer is useful for molding into shrinkage films, agricultural films, etc.

The present disclosure relates to a linear low-density polyethylene copolymer and a preparation method thereof. The linear low-density polyethylene copolymer has a long-chain branching (LCB) distribution similar to that of general metallocene polyethylene (mPE) and has good mechanical properties such as processability and toughness. Thus, the linear low-density polyethylene copolymer is useful for molding into shrinkage films, agricultural films, etc.