This invention relates to polyolefin compositions. In particular, the invention pertains to elastic polymer compositions that can be more easily processed on cast film lines, extrusion lamination or coating lines. The compositions of the present invention preferably comprise an elastomeric polyolefin resin and a high pressure low density type resin.

Compositions of ethylene/alpha-olefin multi-block interpolymer for elastic films and laminates

Transition-metal-catalyzed copolymerization of olefins with polar monomers represents a challenge because of the large variety of substrate-induced side reactions. However, this approach also holds the potential for the direct synthesis of polar functionalized polyolefins with unique properties. After decades of research, only a few catalyst systems have been found to be suitable for this reaction. Some major advances in catalyst development have been made in the past five years. This Minireview summarizes some of the recent progress in the extensively studied Brookhart and Drent catalyst systems, as well as emerging alternative palladium and nickel catalysts.

Emerging Palladium and Nickel Catalysts for Copolymerization of Olefins with Polar Monomers.

The introduction of even a small amount of polar functional groups into polyolefins could excise great control over important material properties. As the most direct and economic strategy, the transition-metal-catalyzed copolymerization of olefins with polar, functionalized monomers represents one of the biggest challenges in this field. The presence of polar monomers usually dramatically reduces the catalytic activity and copolymer molecular weight (to the level of thousands or even hundreds Da), rendering the copolymerization process and the copolymer materials far from ideal for industrial applications. In this contribution, we demonstrate that these obstacles can be addressed through rational catalyst design. Copolymers with highly linear microstructures, high melting temperatures, and very high molecular weights (close to or above 1 000 000 Da) were generated. The direct synthesis of polar functionalized high-molecular-weight polyethylene was thus achieved.

Direct Synthesis of Functionalized High‐Molecular‐Weight Polyethylene by Copolymerization of Ethylene with Polar Monomers

Polymers have become one of the largest and most important materials we use in daily life. Their popularity has stemmed from their wide range of material properties combined with their low cost of ...

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Recent Trends in Catalytic Polymerizations

The ability to carry out transition-metal-catalyzed copolymerizations of olefins with polar monomers is a great challenge in the field of olefin polymerization. Palladium has been the dominant player in this field, while its low-cost nickel counterpart has only achieved very limited success. We report the synthesis and evaluation of a highly versatile platform based on diphosphazane monoxide ligands. Both palladium and nickel catalysts bearing these ligands mediate the copolymerization of ethylene with a number of fundamental polar monomers.

A Versatile Ligand Platform for Palladium- and Nickel-Catalyzed Ethylene Copolymerization with Polar Monomers.

Moderately isospecific homopolymerization of propylene and the copolymerization of propylene and polar monomers have been achieved with palladium complexes bearing a phosphine-sulfonate ligand. Optimization of substituents on the phosphorus atom of the ligand revealed that the presence of bulky alkyl groups (e.g. menthyl) is crucial for the generation of high-molecular-weight polypropylenes (Mw ≈10(4) ), and the substituent at the ortho-position relative to the sulfonate group influences the molecular weight and isotactic regularity of the obtained polypropylenes. Statistical analysis suggested that the introduction of substituents at the ortho-position relative to the sulfonate group favors enantiomorphic site control over chain end control in the chain propagation step. The triad isotacticity could be increased to mm=0.55-0.59, with formation of crystalline polar polypropylenes, as supported by the presence of melting points and sharp peaks in the corresponding X-ray diffraction patterns.

Crystalline Isotactic Polar Polypropylene from the Palladium-Catalyzed Copolymerization of Propylene and Polar Monomers.

A polyolefin based biaxially oriented multi-layer film having at least one surface layer comprise of the propylene-ethylene random block copolymer; The propylene-ethylene random block copolymer obtained through sequential polymerization catalyzed by a metallocene component which is composed of 30 to 70 wt % of a propylene-ethylene random copolymer component having an ethylene content of 1 to 7 wt % produced in the first step of the polymerization and from 70 to 30 wt % of a low crystallinity or an amorphous propylene-ethylene random copolymer component produced in the second step of the polymerization having an ethylene content of 6 to 15 wt % higher than that of the polymer component obtained in the first step, wherein that shows a single peak at 0° C. or lower in the temperature-loss tangent (tanδ) curve obtained by dynamic mechanical analysis (DMA).

Propylene-ethylene random block copolymer and biaxially oriented multi-layer film using the same as a surface layer

PROBLEM TO BE SOLVED: To improve transparency and flexibility in a polyolefin-based elastomer and suppress stickiness and bleed out in a propylene-ethylene random block copolymer. SOLUTION: The propylene-ethylene random block copolymer is obtained by carrying out successive polymerization by using a metallocene-based catalyst. The block copolymer is composed of (A) a crystalline copolymer component in which an elution curve in elution and fractionation method by rise of temperature exhibits a peak T(A) on high-temperature side between 65°C and 88°C and (B) a low-crystalline or amorphous copolymer component in which the elution curve exhibits or does not exhibit a peak T(B) on lower temperature side at ≤40°C. In the block copolymer. the integrated amount of the component eluting when the temperature is raised to a temperature T(C) which is an intermediate point of both peaks is 30-70 wt% and the integrated amount of the component eluting at ≥T(C) is 70-30 wt.% and a temperature T(D) at which 99 wt.% of total copolymer is eluted is ≤90°C and tan δ has a single peak at ≤0°C in a temperature loss tangent curve obtained by measurement of solid viscoelasticity. COPYRIGHT: (C)2005,JPO&NCIPI

Propylene-ethylene random block copolymer

PROBLEM TO BE SOLVED: To improve the transparency, flexibility, heat resistance and cold resistance (at a freezing storage temperature of -30°C) of propylene-ethylene random block copolymer. SOLUTION: This resin composition comprises propylene-ethylene random block copolymer component (A) and an ethylene-α-olefin copolymer component (B), wherein the components (A) and (B) satisfy the following conditions. The component (A) is a block copolymer obtained by sequentially polymerizing propylene homopolymer or propylene-ethylene random copolymer component (A1) and propylene-ethylene random copolymer component (A2) containing ethylene in a larger amount by 5 to 20 wt. % than that of the component (A1), in the presence of a metallocene-based catalyst, and having specific physical properties. The component (B) is a block copolymer obtained by copolymerizing ethylene with a 3 to 12C α-olefin in the presence of a metallocene-based catalyst, and having specific physical properties. COPYRIGHT: (C)2005,JPO&NCIPI

Resin composition comprising propylene-ethylene random block copolymer and various molded products obtained by molding the same

PROBLEM TO BE SOLVED: To provide a propylene-based resin film high in impact resistance and excellent in transparency and blocking resistance, etc. SOLUTION: The propylene-based resin film meets the following requirements (A-i) to (A-iv): (A-i) It consists of a propylene-ethylene random block copolymer comprising 30-85 wt.% of (A1) a component obtained in a first step, 0.5-6 wt.% in ethylene content, synthesized using a metallocene-based catalyst and 70-15 wt.% of (A2) a component obtained in a second step, containing an ethylene component more than the component (A1) by 6-18 wt.%. (A-ii) In the TREF (temperature rising elution fractionation) elution curve, the peak T (A1) at higher temperature side falls within the range from 55°C to 96°C, while the peak T (A2) at lower temperature side falls below 45°C, and the temperature T (A4) at which 99 wt.% of the whole block copolymer is eluted is below 98°C. (A-iii) The MFR falls within the range of 1-50 g/10 min. (A-iv) The tanδ curve determined by solid viscoelasticity measurement has a single peak below 0°C. COPYRIGHT: (C)2007,JPO&INPIT

Shinichi Kitade

Papers

Crystalline Isotactic Polar Polypropylene from the Palladium-Catalyzed Copolymerization of Propylene and Polar Monomers.

Propylene-ethylene random block copolymer and biaxially oriented multi-layer film using the same as a surface layer

Propylene-ethylene random block copolymer

Resin composition comprising propylene-ethylene random block copolymer and various molded products obtained by molding the same

Propylene-based resin film and propylene-based resin laminated film and application thereof