Abstract: To provide a uniaxially oriented polypropylene-based film excellent in tensile elongation along the TD direction and transparence, and generating less fibers when it is torn, a film-forming material which comprises a polypropylene-based resin material consisting of 40 to 95% by weight of crystalline polypropylene, and 60 to 5% by weight of propylene-&agr;-olefin copolymer dispersed as particles in the crystalline polypropylene is uniaxially oriented to afford a uniaxially oriented polypropylene-based film, wherein the particles of the copolymer have an aspect ratio (L/D) of mean dispersed particle length (L) to mean dispersed particle diameter along the film thickness direction (D) of 100 or more in a cross section of the film along the MD direction, and the mean dispersed particle diameter of 0.10 &mgr;m or less.

Abstract: The invention provides a process for producing polypropylene and/or random copolymers of propylene type using a stereoregular catalyst which comprises a titanium-containing solid catalyst component (A), an organoaluminum compound (B) and if required an organosilicon compound (C), wherein [I] before carrying out homopolymerization of propylene or random copolymerization of propylene with an &agr;-olefin other than propylene, the above component (A), an organoaluminum compound (B′) and if required an organosilicon compound (C′) are used, and a small amount of propylene or ethylene and/or an &agr;-olefin of 4-20 carbon atoms for pre-activation treatment is supplied to the above component (A), and [II] a catalyst which is prepared by adding an organosilicon compound (C″) to the pre-activated stereoregular catalyst in a molar ratio of 0.1-50 as Si/Ti, is used to produce polypropylene or propylene random copolymers.

Abstract: An object of the present invention is to provide a drawn polypropylene film as a wrapping material that has transparency and mechanical properties sufficient as a wrapping material yet having the needed gas permeability for maintaining the freshness of the enclosed goods and additionally enables control of permeability of gases to a certain proportion if needed even if secondary steps such as perforation processing, etc., are eliminated.

Abstract: To provide an economically advantageous biaxially oriented polypropylene-based film, which is excellent in straight cuttability along the MD direction, strength along the TD direction and transparency, a film-forming material which comprises a polypropylene-based resin material consisting of 40 to 88% by weight of crystalline polypropylene, and 60 to 12% by weight of propylene-&agr;-olefin copolymer dispersed as particles in the crystalline polypropylene is biaxially oriented to afford a biaxially oriented polypropylene-based film wherein the particles of the copolymer have a mean dispersed particle diameter of 0.1 &mgr;m or less along the TD direction.

Abstract: A propylene polymer blend is disclosed which comprises (A) a propylene-&agr;-olefin random copolymer with a propylene content of 90 to 99% by weight and (B) a propylene-&agr;-olefin random copolymer with a propylene content of 55 to 90% by weight, wherein the intrinsic viscosity ([&eegr;B]) of the copolymer B ranges from 1.3 to 3.5 dl/g, the ratio ([&eegr;B]/[&eegr;A]) of the intrinsic viscosity ([&eegr;B]) of the copolymer B to the intrinsic viscosity ([&eegr;A]) of the copolymer A ranges from 0.5 to 1.3 and a product (([&eegr;B]/[&eegr;A])×(WA/WB)) of the intrinsic ratio ([&eegr;B]/[&eegr;A]) of both copolymers and the weight ratio (WA/WB) of both copolymers ranges from 1.0 to 4.5. A polypropylene resin composition comprises 99 to 99.9999% by weight of the propylene polymer blend and 1 to 0.0001% by weight of an &agr;-crystal nucleating agent.

Abstract: A polypropylene composition for the production of various molded articles which are excellent in moldability, mold shrinkage factor on molding, rigidity, flexibility, impact resistance, in particular low-temperature impact resistance, transparency, gloss, stress-whitening resistance, and the balance thereof; various molded articles having the above properties; a propylene composition which is suitable for a base resin for the polypropylene composition; and a process for the production thereof. The propylene composition comprises a propylene homopolymer and a propylene-ethylene copolymer, the intrinsic viscosity of the copolymer ([&eegr;]RC) is in the range of 1.7 to 2.8 dl/g, the intrinsic viscosity ratio of the homopolymer to the copolymer ([&eegr;]RC/[&eegr;]pp) is in the range of 0.7 to 1.

Abstract: A polypropylene composition which contains 0.01 to 5 parts by weight of an olefin (co)polymer (a) having an intrinsic viscosity of 15 to 100 dl/g, 100 parts by weight of a propylene homopolymer (b) having an intrinsic viscosity of 0.2 to 10 dl/g, and 28 to 300 parts by weight of an ethylene/propylene copolymer (c) having an intrinsic viscosity of 0.2 to 10 dl/g, and in which the ratio of the melt flow rate of the homopolymer (b) to that of the copolymer (c), MFRPP/MFRRC, is 0.3 to 4 and the product of the ratio of the intrinsic viscosity of the copolymer (c) to that of the homopolymer (b), [&eegr;]RC/[&eegr;]PP, and the weight ratio of the amount of the homopolymer (b) to that of the copolymer (c), WPP/WRC, is in the range of from 0.2 to 3.0. The composition has high melt tension, high crystallization temperature, and excellent thermal stability, and yields a molded article having excellent transparency, reduced molding shrinkage, and excellent resistance to whitening by impact or bending.

Abstract: An unoriented polypropylene-based film or sheet possessing excellent impact resistance at low temperature, transparency, heat resistance at low temperature and excellent tear strength and/or stress whitening resistance. A molding material which comprises a polypropylene-based resin material comprising 40 to 80% by weight of crystalline polypropylene and 60 to 20% by weight of propylene-&agr;-olefin copolymer containing 20 to 80% by weight of propylene polymerization units, the propylene-&agr;-olefin copolymer dispersed as particles in the crystalline polypropylene, is unoriently molded to afford a film-shaped or sheet-shaped molding, wherein the particle diameter have an aspect ratio (L/D) of mean dispersed particle length (L) to mean dispersed particle diameter along the thickness of the molding (D) of 30 or more in a cross section of the molding along the MD direction, and the mean dispersed particle diameter of 0.3 &mgr;m or less.

Abstract: A polyolefin type resinous composition comprising 99 to 80% by weight of a propylene type block copolymer [A] and 1 to 20% by weight of an ethylene type or styrene type elastomer [B] which being superior in a transparency, a coloring property and a dimensional stability is provided. The said polyolefin composition comprises the said [A] consisting of a propylene homopolymer component and an ethylene propylene copolymer component having respective limiting viscosities: [&eegr;]PP, [&eegr;]RC, weight %: WPP, WRC, and melt flow rates: [MFR]PP, [MFR]RC, as well as the said [B] having a limiting viscosity: [&eegr;]R and a melt flow rate: [MFR]R, in such a way that the following relationships being established; ([&eegr;]RC/[&eegr;]PP)×(WPP/WRC)=0.2-3.0, ([MFR]RC/[MFR]PP)=0.3-4.0, [&eegr;]RC/[&eegr;]PP=0.7-1.