Abstract: An ethylene-&agr;-olefin copolymer obtained by a gas phase polymerization method in the presence of a catalyst, wherein the copolymer satisfies the following conditions (A-1) to (A-4): (A-1) Melt flow rate (MFR): 0.3 to 5.0 g/10 minutes (A-2) Melt flow rate ratio (MFRR): 20 or more (A-3) Density (d): 0.910 to 0.930 g/cm3 (A-4) Coldxylene-soluble portion (CXS)(wt %) is in the range defined by the formula (1): 1.5×10−4×d−125×MFR0.5+0.3≧CXS  formula (1).

Abstract: A polypropylene random copolymer obtained by copolymerizing propylene and an &agr;-olefin or propylene, ethylene, and &agr;-olefin using a Ziegler-Natta catalyst substantially in the absence of solvent, wherein propylene content is from 92.3 to 75.0% by weight, the ethylene content (E) is from 0 to 2.7% by weight, and the &agr;-olefin content is from 5.0 to 25.0% by weight, and wherein the content (C) of 20° C. xylene-soluble components in the random copolymer satisfies following formulae (1) to (3); in the copolymer wherein the ethylene content (E) is less than 1.5% by weight, C≦12.0 (weight %)  (1) in the copolymer wherein the ethylene content (E) is from 1.5% by weight to 1.8% by weight, C≦42.0−20.0×E (weight %)  (2) and in the copolymer wherein the ethylene content (E) is from 1.8% by weight to 2.7% by weight, C≦6.0 (weight %)  (3).

Abstract: A propylene-ethylene random copolymer prepared by copolymerizing propylene with ethylene in the substantial absence of a liquid medium with a catalyst system comprising:(A) a solid catalyst component containing magnesium, titanium, a halogen and a first electron donor as an essential component,(B) an organoaluminum compound and(C) a second electron donor compound, wherein an ethylene content (E) of the copolymer is from 3.5 to 7.0% by weight, and wherein a content of a xylene-soluble portion at 20.degree. C. (D) of the copolymer satisfies the relationship D.ltoreq.E+2.0 (% by weight). Films of the copolymer have an excellent appearance (little bleed whitening) and an excellent balance between low-temperature heat-sealing property and rigidity.

Abstract: A film having a low dependency of film transparency on film-forming conditions and film thickness, and having superior transparency and rigidity without compromising the original properties of polypropylene film. The film is produced from a polypropylene prepared from a propylene polymer having (1) a stereoirregularity index mmrr/mmmm of a part insoluble in xylene at 20.degree. C. within the range of 0.0095 to 0.0200; (2) a melting temperature within the range of 145.degree. to 160.degree. C.; (3) a part soluble in xylene at 20.degree. C. of 3.5% by weight or less, the polypropylene having: (4) a melt flow rate at 230.degree. C. within the range of 5 to 15 g/10 min.; and (5) a swelling ratio within the range of 1.20 to 1.35.

Abstract: A polypropylene composition comprising a melt-kneaded polyprolylene composition obtained, using Zieglar-Natta catalyst, by polymerizing a monomer comprising propylene to form a polymer comprising polypropylene (component A) in amount of from 60 to 80% by weight to the total polymer amount in substantially the absence of an inert solvent in a 1st step and then polymerizing a mixture of ethylene content of from 20 to 50% by weight (component B) in a vapor phase to form an ethylene-propylene copolymer (component B) in amount of from 20 to 40% by weight to the total polymer amount in a 2nd step, said polypropylene composition being such that the intrinsic viscosity of component B ([.eta.]B) is at least 2.0 dl/g and the ratio ([.eta.]B/[.eta.]A) of the intrinsic viscosity of the component B to the intrinsic viscosity of the component A ([.eta.]A) is 1.8 or less and the melt flow rate of the polypropylene composition after melt-kneaded being 0.5 to 10 g/10 minutes.

Abstract: A polypropylene composition comprising 100 parts by weight of a crystalline propylene polymer having a molecular weight distribution (Mw/Mn) of less than 5.0 and from 0.0001 to 1.0 part by weight of a crystal nucleating agent, the composition having a crystallization temperature at least 1.5.degree. C. higher than the crystallization temperature of the crystalline propylene polymer.

Abstract: A polypropylene composition comprising 100 parts by weight of a crystalline propylene polymer having a melt flow rate of at least 3.0 g/10 minutes and a molecular weight distribution of less than 5.0 and from 0.01 to less than 4.0 parts by weight of a crystalline ethylene polymer having a melt flow rate of from 0.5 to 300 g/10 minutes, a density of at least 0.910 g/cm.sup.3, and a crystallization temperature of at least 85.degree. C. and which is at least 1.degree. C. higher than the crystallization temperature of the crystalline propylene polymer.

Abstract: The polypropylene stretched film of the present invention is prepared by stretching a composition comprising a crystalline propylene polymer and 0.1 ppm by weight to 10% by weight of a nucleating agent, the composition having a melting point of 160.degree. C. or more, a crystallization temperature of 128.degree. C. or more and a 20.degree. C. xylene soluble portion of 3.0% by weight or less. The film has a high rigidity and a beautiful appearance as well as the characteristic properties inherent to crystalline propylene polymers. The film can be suitably used for food packaging and textile packaging.

Abstract: The polypropylene stretched film of the present invention is prepared by stretching a composition comprising a crystalline propylene polymer and 0.1 ppm by weight to 10% by weight of a nucleating agent, the composition having a melting point of 160.degree. C. or more, a crystallization temperature of 128.degree. C. or more and a 20.degree. C. xylene soluble portion of 3.0% by weight or less. The film has a high rigidity and a beautiful appearance as well as the characteristic properties inherent to crystalline propylene polymers. The film can be suitably used for food packaging and textile packaging.

Abstract: The overlay film of the invention is obtained by forming a substrate layer composed of a resin composition comprising an ethylene copolymer such as ethylene-methacrylic acid ester copolymer and the like and a crystalline polyolefin having a melting point of 110.degree. C. or higher on at least one side of the base layer composed of a crystalline polyolefin and the like by any method such as co-extrusion-laminating and the like followed by cooling. The overlay film is excellent in physical properties such as the anti-blocking property and the like and gives a metal-deposited film with brilliant appearance exhibiting high adhesive strength to the metal layer by vapor-deposition treatment. The metal-deposited film is serviceable for extensive uses including wrapping materials.

Abstract: A monolayer polypropylene film obtained by melt extrusion from a composition comprising 100 parts by weight of a crystalline polypropylene and, incorporated therein, a slipping agent {A} having a melting point of 100.degree. to 125.degree. C. and a slipping agent {B} having a melting point of 70.degree. to 90.degree. C. in a total amount of 0.05 to 1.0 part by weight, the initial coefficient of friction of said film being 0.7 or below and the coefficient of friction after heating at 60.degree. C. being 1.0 or below; and a multilayer film composed of said polypropylene film layer having said composition and said characteristics and a substrate material layer.

Abstract: A monolayer polypropylene film obtained by melt extrusion from a composition comprising 100 parts by weight of a crystalline polypropylene and, incorporated therein, a slipping agent [A] having a melting point of 100.degree. to 125.degree. C. and a slipping agent [B] having a melting point of 70.degree. to 90.degree. C. in a total amount of 0.05 to 1.0 part by weight, the initial coefficient of friction of said film being 0.7 or below and the coefficient of friction after heating at 60.degree. C. being 1.0 or below; and a multilayer film composed of said polypropylene film layer having said composition and said characteristics and a substrate material layer.

Abstract: A polypropylene multi-layer film which comprises a crystalline polypropylene substrate layer having laminated to at least one side thereof a sheet of a resin composition comprising:(A) 10-90% by weight of a propylene random copolymer satisfying that(i) the comonomer content is 4-15% by weight,(ii) the Vicat softening point is 122.degree. C. or less, and(iii) the cold xylene-soluble portion content is 15% by weight or less,(B) 10-90% by weight of a copolymer of propylene and an .alpha.-olefin having four or more carbon atoms or a copolymer of propylene, an .alpha.-olefin having four or more carbon atoms and ethylene satisfying that:(i) the content of the .alpha.-olefin having four or more carbon atoms is 8-35 mole %,(ii) the ethylene content is 5 mole % or less,(iii) the cold xylene-soluble portion content is 15-70% by weight, and(iv) the .DELTA.haze is 5% or less, and(C) 0-15% by weight of a highly crystalline polypropylene having a melting point of 150.degree. C. or more.

Abstract: A polypropylene multi-layer film which comprises a substrate layer formed of crystalline polypropylene and a composition laminated on at least one side of said substrate layer, said composition comprising 70 to 95% by weight of (A) a crystalline propylene-ethylene copolymer having an ethylene content of 1.5 to 6.0% by weight and/or a crystalline propylene-.alpha.-olefin copolymer having a propylene content of 80 to 98% by weight, a butene-1 content of 2 to 20% by weight, and an ethylene content of 0 to 5% by weight, and 5 to 30% by weight of (B) a crystalline propylene-butene-1 copolymer which is a copolymer obtained by decomposing a crystalline propylene-butene-1 copolymer having a butene-1 content of 25 to 45% by weight, an intrinsic viscosity of 2.5 dl/g or more as determined in tetralin at 135.degree. C., and a proportion of 35% by weight or more of a polymer component soluble in xylene at 20.degree. C., and containing 1.

Abstract: A stretched polypropylene film having excellent see-through characteristics, which is prepared by stretching in at least one direction a polypropylene resin sheet containing 0.05 ppm to 10,000 ppm by weight of a 3-position branched .alpha.-olefin unit and/or a vinyl cycloalkane unit, each having at least 6 carbon atoms.

Abstract: A stretched multilayer polypropylene film is described, comprising a stretched crystalline polypropylene layer and a layer of a composition (Composition B) laminated on at least one side of said polypropylene layer, wherein the composition B comprises a homo- or copolymer composed mainly of ethylene, propylene or butene-1 and having a melting point of 150.degree. C. or less, and a vinylcycloalkane polymer in an amount of 0.05 wt ppm to 10 wt % calculated as a vinylcycloalkane unit. This multilayer film is greatly improved in optical properties such as excellent see-through properties without deteriorating its good heat sealability. Thus it is very useful for wrapping.

Abstract: A propylene block copolymer produced by polymerizing propylene, ethylene and an .alpha.-olefin having 4 to 8 carbon atoms in two stages with a Zieglar-Natta catalyst by a process which comprises (A) supplying propylene and ethylene in the first stage and propylene and the .alpha.-olefin in the second stage, or (B) supplying propylene and the .alpha.-olefin in the first stage and propylene and ethylene in the second stage, to the polymerization system, wherein the amounts of propylene and ethylene supplied in the first stage of (A) or in the second stage of (B) are 90 to 99 wt % and 10 to 1 wt % based on the total amount of propylene and ethylene supplied in the first stage of (A) or in the second stage of (B), respectively, the amounts of propylene and the .alpha.-olefin supplied in the second stage of (A) or in the first stage of (B) are 60 to 98 wt % and 40 to 2 wt % based on the total amount of propylene and the .alpha.

Abstract: In a process for producing polypropylene comprising polymerizing propylene in the presence of hydrogen and a catalyst system comprising (A) titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound and reacting the reduced solid with an ether represented by the formula:R.sup.1 --O--R.sup.2wherein R.sup.1 and R.sup.2 are defined hereinbefore, and a halogen compound selected from the group consisting of (i) halogen or interhalogen compounds of the formula, X.sup.1 X.sup.2.sub.a (wherein X.sup.1, X.sup.2 and a are defined hereinbefore), (ii) titanium halides, and (iii) organic halogen compounds, simultaneously or successively and (B) an organoaluminum compound, the improvement which comprises supplying ethylene together with propylene to the polymerization system such that the ethylene concentration in the vapor phase of the system based on the total amount of propylene, ethylene and hydrogen in the vapor phase of the system is 0.15 to 1.

Abstract: In a process for producing polypropylene comprising polymerizing propylene in the presence of hydrogen and a catalyst system comprising (A) titanium trichloride obtained by reducing titanium tetrachloride with an organoaluminum compound and reacting the reduced solid with an ether represented by the formula:R.sup.1 -O-R.sup.2wherein R.sup.1 and R.sup.2 are defined hereinbefore, and a halogen compound selected from the group consisting of (i) halogen or interhalogen compounds of the formula, X.sup.1 X.sup.2.sub.a (wherein X.sup.1, X.sup.2 and a are defined hereinbefore), (ii) titanium halides, and (iii) organic halogen compounds, simultaneously or successively and (B) an organoaluminum compound, the improvement which comprises supplying ethylene together with propylene to the polymerization system such that the ethylene concentration in the vapor phase of the system based on the total amount of propylene, ethylene and hydrogen in the vapor phase of the system is 0.15 to 1.

Abstract: A molded product of polypropylene having an isotactic pentad fraction of the boiling heptane insoluble portion of at least about 0.955 and a boiling heptane solubles content of about 2.0 to 9.0% by weight. The molded products include a stretched film, insulating materials for electrical equipment, etc.