Mitsui Chemicals, Inc.

Mitsui Petrochemical Industries, Ltd.

Mamoru Kagami

Yasuo Tanaka

Masahiro Sugi

Toshiyuki Tsutsui

Akira Todo

Mikio Hashimoto

Ryoji Mori

Takashi Nakagawa

Mutsuhiro Tanaka

Tatsuya Tanizaki

Seiki Maeda

The invention provides a propylene polymer composition well balanced and excellent in transparency, flexibility, heat resistance, scratch resistance and rubber elasticity, and a medical tube made from the propylene polymer composition. The propylene polymer composition satisfies all the following properties (A), (B), (C) and (D): (A) the composition shows a loss tangent (tan &#x3b4;) peak at a temperature in the range of &#x2212;20 to 25&#xb0; C. according to dynamic viscoelasticity measurement (10 rad/s) in a torsion mode, and the peak is 0.5 or above; (B) the storage elastic modulus G' at 20&#xb0; C. from the dynamic viscoelasticity measurement is in the range of 1.0&#xd7;10to 4.9&#xd7;10dyn/cm; (C) the penetration temperature (&#xb0; C.) determined in accordance with JIS K 7196 is in the range of 60 to 160&#xb0; C.; and (D) the composition has a permanent set of not more than 30% as determined after the composition fixed between chucks 30 mm apart is 100% strained at a stress rate of 30 mm/min, maintained for 10 minutes and released for 10 minutes. The medical tube is made from the propylene polymer composition.

Propylene polymer composition and use thereof

Soft resin compositions comprising a polyethylene resin (A) and an ethylene/&#x3b1;-olefin random copolymer (B) comprising ethylene and an &#x3b1;-olefin having 3 to 20 carbon atoms at a specific proportion, or an ethylene/&#x3b1;-olefin copolymer resin composition comprising a linear ethylene/&#x3b1;-olefin copolymer (A-&#x3b1;) comprising ethylene and an &#x3b1;-olefin having 4 to 20 carbon atoms and a long-chain branched ethylene/&#x3b1;-olefin random copolymer (B-&#x3b1;) comprising ethylene and an &#x3b1;-olefin having 3 to 20 carbon atoms in a specific proportion, wherein a density and MFR of the polyethylene resin (A) and the copolymer (A-&#x3b1;), and a density, MFR, intrinsic viscosity, glass transition temperature crystallinity, molecular weight distribution, B value and g&#x3b7;* values of the copolymers (B) and (B-&#x3b1;) are each in a specific range.

Resin compositions and use of the same

Soft resin compositions comprising a polyethylene resin (A) and an ethylene/&agr;-olefin random copolymer (B) comprising ethylene and an &agr;-olefin having 3 to 20 carbon atoms at a specific proportion, or an ethylene/&agr;-olefin copolymer resin composition comprising a linear ethylene/&agr;-olefin copolymer (A-&agr;) comprising ethylene and an &agr;-olefin having 4 to 20 carbon atoms and a long-chain branched ethylene/&agr;-olefin random copolymer (B-&agr;) comprising ethylene and an &agr;-olefin having 3 to 20 carbon atoms in a specific proportion, wherein a density and MFR of the polyethylene resin (A) and the copolymer (A-&agr;), and a density, MFR, intrinsic viscosity, glass transition temperature, crystallinity, molecular weight distribution, B value and g&eegr;* values of the copolymers (B) and (B-&agr;) are each in a specific range.

The polypropylene composite film of the present invention comprises (A) a crystalline polypropylene layer and (B) a propylene-1-butene random copolymer layer which is laminated on at least one surface of the crystalline polypropylene layer (A). The propylene/1-butene random copolymer (B) has the following properties: (1) the copolymer comprises 50 to 95% by mol of constituent units derived from propylene and 50 to 5% by mol of constituent units derived from 1-butene, (2) the intrinsic viscosity is 0.1 to 5 dl/g, (3) the molecular weight distribution (Mw/Mn) is not less than 3, and (4) the parameter B value is 1.0 to 1.5. The crystalline polypropylene layer (A) of this composite film may be unstretched, monoaxially stretched or biaxially oriented. The polypropylene composite film has excellent heat-sealing properties, such as low-temperature heat-sealing properties and heat-sealing strength, and hot tack properties. The polypropylene composite film is almost free from surface tackiness and shows good slip properties and high blocking resistance at high temperatures, so that it is suitable for high-speed packaging. In addition, this composite film also has good transparency and scratch resistance. The polypropylene composite film of the invention having the above-mentioned excellent properties can be favorably used for packaging of foods, fill packaging and fiber packaging.

Polypropylene composite film

The resin composition of the invention is a composition which includes 100 parts by weight of a polyethylene resin (A) and 2 to 5,000 parts by weight of a linear ethylene/a-olefin random copolymer (B) which includes ethylene and an a-olefin of 6 to 20 carbon atoms, wherein the polyethylene resin (A) has (a) MFR (ASTM D 1238, 190&deg; C., load of 2.16 kg) of 0.1 to 200 g/10 min and (b) a density of 0.901 to 0.970 g/cm ; and the copolymer (B) has (a) a density of 0.870 to 0.900 g/cm , (b) an intrinsic viscosity (&eegr;), as measured in decalin at 135&deg; C., of 0.3 to 3.0 dl/g, (c) a glass transition temperature (Tg) of not higher than &minus;50&deg; C., (d) a crystallinity, as measured by X-ray diffractometry, of less than 40%, (e) a molecular weight distribution (Mw/Mn), as measured by GPC, of not more than 3.0, (f) a B value, as determined by the C-NMR spectrum and a specific equation, of 1.0 to 1.4, and (g) a ratio g&eegr;* of more than 0.95 (g&eegr;*&equals;(&eegr;)/(&eegr;) (&eegr;): intrinsic viscosity of this copolymer determined in the property (b), (&eegr;) : intrinsic viscosity of a linear ethylene/propylene copolymer having the same weight-average molecular weight (measured by a light scattering method) as this copolymer and having an ethylene content of 70% by mol). This resin composition can provide molded products of excellent pliability and tensile properties.

Hollow vessel for heat sterilization

Disclosed is a polypropylene composition comprising (A) polypropylene and (B) a specific propylene-1-butene random copolymer in a specific amount ratio. The propylene-1-butene random copolymer (B) is characterized in that: (1) the copolymer contains 50 to 95% by mol of constituent units from propylene and 50 to 5% by mol of constituent units from 1-butene, (2) the intrinsic viscosity, as measured in decahydronaphthalene at 135.degree. C., is in the range of 0.1 to 12 dl/g, (3) the molecular weight distribution (Mw/Mn), as determined measured by GPC, is not more than 3, and (4) the parameter B value indicating randomness of the copolymerized monomer sequence distribution is in the range of 1.0 to 1.5. Also disclosed is a polypropylene composite film comprising (I) a crystalline polypropylene layer and (II) a layer formed from the polypropylene composition, which is laminated on at least one surface of the crystalline polypropylene layer (I). The polypropylene composition is excellent in heat resistance and low-temperature heat-sealing properties as well as in flexibility and impact resistance. The polypropylene composite film is excellent in not only heat-sealing properties, particularly low-temperature heat-sealing properties, but also transparency, scratch resistance and blocking resistance.

Growing community of inventors

Ichihara, Japan

Mamoru Kagami