Abstract: The object of the present invention is to provide a method for producing a polyester film excellent in rigidity, toughness, dimensional stability, electric properties, etc. and less in thickness fluctuation and surface defects, hence very suitable as a film for various industrial materials such as magnetic recording media, capacitors, heat transfer ribbons and thermal mimeographic stencil paper. The first method of the present invention is a method for producing a polyester film, in which a film made of a resin mainly composed of a polyester is simultaneously biaxially stretched by a simultaneously biaxially stretching tenter oven, comprising the step of effecting small-ratio stretching at an area stretching ratio of 1.0005 to 3.

Abstract: The present invention provides a method for industrially stably producing a stretched polyamide film having uniform properties at a high speed. The polyamide film production method comprises the steps of: extruding a molten polyamide resin from a die into a sheet form on a rotary cooling roll having a roughened surface; pressing the sheet against the surface of the cooling roll with an air layer being present between the cooling roll and the sheet by blowing air onto the sheet from an air knife apparatus for cooling the sheet, the air layer having a widthwise thickness distribution such that an average air layer thickness Te in lateral edge regions of the sheet is greater than an average air layer thickness Tc in a middle region of the sheet; and biaxially stretching the sheet.

Abstract: A fluororesin film, which has a dielectric constant of at most 5, and which has a tensile break strength of at least 40 MPa in each of MD direction and TD direction; a fluororesin film, wherein the ratio of the tensile break strength in each of MD and TD directions after stretching to the tensile break strength in each of MD and TD directions before stretching, is at least 1.5; and a fluororesin film, which has a tensile modulus of at least 3,000 MPa in each of MD and TD directions. The above-mentioned fluororesin films are obtained by using a method of biaxially stretching laminates of corresponding raw fabric films and readily stretchable films.

Abstract: A transversely stretched nonwoven fabric is manufactured by transversely stretching a nonwoven fabric. First, an original web comprising a plurality of un-oriented filaments is heated to a temperature higher than its stretch suitable temperature by 5° C. or more. Next, the heated original web is stretched at a rate of 1.2 to 3 in its transverse direction to stretch the filaments of the original web with almost no molecular orientation involved. Then, the original web stretched transversely at a rate of 1.2 to 3 is heated to the stretch suitable temperature and the original web is further stretched transversely at the stretch suitable temperature. With these steps, a transversely stretched nonwoven fabric in which the original web is stretched transversely at a rate of 7 times or more in total as compared with the state of the stretch thereof is manufactured with a high tensile strength of 132.5 mN/tex (1.5 g/d) in the transverse direction.

Abstract: The present invention provides a stable material having enhanced extensibility and a method for making the same. A neckable material is fed in a first direction. The neckable material is subjected to incremental stretching in a direction perpendicular to the first direction. A tensioning force is applied to the neckable material to neck the material in a direction perpendicular to the first direction. The necked material is then subjected to mechanical stabilization to provide a stabilized extensible necked material. The stabilized extensible necked material is then passed between the peripheral surface of a cylinder which is driven in rotating motion and a device for pressing the stabilized extensible necked material against the peripheral surface of the cylinder. A retarding member retards the passage of the stabilized extensible necked material and directs the material away from the peripheral surface of the cylinder.

Abstract: The 4-methyl-1-pentene copolymer multi-layer film according to the present invention is a three-layer laminate or a five-layer laminate, which comprises a layer (A) comprising 4-methyl-1-pentene, a layer (B) comprising polypropylene or polyethylene, and optionally, a layer (C) comprising an adhesive resin, said layer (A) being provided on each surface of the layer (B) in the three-layer laminate or being provided on each surface of the layer (B) through the layer (C) in the five-layer laminate, and this multi-layer film is uniaxially stretched in a stretch ratio of not less than 2 times or biaxially oriented in a stretch ratio of not less than 1.5 times in each of the machine direction and the transverse direction.

Abstract: Toughened biaxially oriented polyamide films prepared by dry blending i) a polyamide homopolymer, copolymer, or blends thereof; and ii) a functionalized polyolefin terpolymer comprising maleic anhydride, ethyl acrylate, and an olefin, to thereby form a dry mixture. The dry mixture is melted to form a polymer blend, which is then formed into a polymer film. The edges of the film are pinned to a casting roll, and the film is plasticized in at least one water bath. The polymer film is subsequently biaxially oriented. The result is a toughened biaxially oriented film which is resistant to pinholes, cracks, and other structural defects. Such films are particularly suited for making packaging materials for various food products.

Abstract: A manufacturing method of adhesive tape, by preparing a raw material of a biaxially or non-drawn, film or sheet on the back surface of which a release agent has been applied and to the which an adhesive agent has been applied, and subjecting the raw material to uniaxial drawing under heated conditions without deteriorating releasing and adhesive performance of the raw material, thus producing an adhesive tape having high-strength and low-elongation. The obtained adhesive tape has long and narrow bubbles elongated in the uniaxial drawing direction thereon.

Abstract: A process for producing a polyester sheet by dropping a molten polyester sheet extruded from an orifice-form nozzle on a cooling roll having the grooves of a large number of micro-cracks formed on the surface, closely adhering it to the cooling roll and solidifying it on the cooling roll, wherein

Abstract: Provided is a porous film which is excellent in a water vapor transmission rate, a tear strength and a weatherability. This porous film can be produced by melt-extruding, for example, by a T-die method, a composition comprising 100 parts by weight of a resin blend (1) comprising 100 parts by weight of {circle around (1)} an ethylene-propylene copolymer, 3 to 40 parts by weight of {circle around (2)} a low density polyethylene and 3 to 40 parts by weight of {circle around (3)} an ethylene-vinyl acetate copolymer and 100 to 200 parts by weight of calcium carbonate (2), or a composition comprising 100 parts by weight of the above resin blend (1), 100 to 200 parts by weight of calcium carbonate (2), 0.5 to 20 parts by weight of titanium dioxide (3) coated on a surface thereof with silica and/or alumina, 0.2 to 10 parts by weight of a hindered amine light stabilizer (4) having a molecular weight of 1500 to 4500 and 0.

Abstract: The present invention is directed to a process for producing a biaxially oriented polyester film which comprises: subjecting a polyester film to simultaneous biaxial stretching in a stretching apparatus constructed to simultaneously stretch the film in the lengthwise and widthwise directions thereof: and subsequently subjecting the film to successive biaxial stretching in the lengthwise and widthwise directions thereof in the same apparatus as mentioned above. With this process, a film can be efficiently formed, without film breaking, which film is small in thickness and greatly strong in its lengthwise and widthwise directions.

Abstract: A fibrillated foamed article and process for producing the same is described. The fibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as a diffuse reflector for use in optical applications such as computer displays and as reinforcement fibers for polymers or cast building materials such as concrete.

Abstract: The present invention relates to shape deformable materials, which are capable of (1) being deformed, (2) storing an amount of shape deformation, and (3) recovering at least a portion of the shape deformation when exposed to electromagnetic radiation (EMR) energy. The shape deformable materials can advantageously be in the form of films, fibers, filaments, strands, nonwovens, and pre-molded elements. The shape deformable materials of the present invention may be used to form products, which are both disposable and reusable. More specifically, the shape deformable materials of the present invention may be used to produce products such as disposable diapers, training pants, incontinence products, and feminine care products.

Abstract: The present invention provides a heat shrinkable polyester film whose hot water shrinkage along its main shrinkage direction is equal to or greater than 20% when the film is put in hot water of 70° C. for 5 sec; 35% to 55% when put in hot water of 75° C. for 5 sec; and 50% to 60% when put in hot water of 80° C. for 5 sec, wherein the compressive strength of the label formed by the film satisfies a following expression (1): Y>X2.2  (1) where y denotes compressive strength (mN) and x denotes film thickness (&mgr;m).

Abstract: Polymeric films including a layer of propylene resin having microvoids therein, the microvoids having been formed by stretching a web containing the beta-form of polypropylene, have shown low static cling when being unwound from rolls in labelling operations and also during destacking of pre-formed labels. The invention provides labels formed from such films.

Abstract: The present invention relates to a cold-drawn breathable film formed from a blend of a soft polymer component and a hard polymer component. The soft polymer component (SPC) is a copolymer of a major olefinic monomer and a minor olefinic monomer. The major olefinic monomer is either ethylene or propylene and forms the majority of the SPC. Preferred films after cold-drawing exhibit a water vapor transmission rate (WVTR) of at least 100 g-mil/m2-day.

Abstract: A biaxially oriented polyester film whose thermal shrinkage factors satisfy relationships represented by the following expressions (1) to (5) at the same time when it is heated at 120° C. for 20 seconds: 0.001≦SMD≦0.1  (1) −0.1≦STD≦0.1  (2) −0.05≦S45≦0.05  (3) −0.05≦S135≦0.05  (4) |S45−S135|≦0.05  (5) wherein SMD is a thermal shrinkage factor (%) in machine direction of the film under the above conditions, STD is a thermal shrinkage factor (%) in a direction perpendicular to that direction under the above conditions, and S45 and S135 are thermal shrinkage factors (%) in a 45° direction and a direction perpendicular to the 45° direction under the above conditions when the machine direction of the film is 0° and a direction perpendicular to that direction is 90°, respectively, and a production method thereof.

Abstract: The invention relates to a biaxially oriented, sealable polyester film with at least a base layer (B), with a sealable outer layer (A) and with another, nonsealable outer layer (C), where the sealable outer layer (A) has a minimum sealing temperature of not more than 110° C. and a seal seam strength of at least 1.3 N/15 mm of film width, and the topographies of the two outer layers (A) and (C) have particular characterizing features. The film of the invention is particularly suitable for use in flexible packaging and specifically in particular for use on high-speed packaging machinery.

Abstract: In order to provide wider biaxially-stretched geogrids having high primary direction (PD) strength, crotch-forming zones of a starting material which is at least 2.0 mm thick have protuberances (6). On strectching, PD orientation passes right through the junction (27) but the protuberance (6) causes the orientation ratio of the crotch edge to decrease significiantly as orientation enters the central part of the crotch edge. After a secondary direction stretch of at least about 1.5:1, the thickness of the central part of the crotch edge is not reduced by more than about 20%. The stretching does not reduce the thickness of any point along notional ridge lines (31) to such an extent that the ratio of finished thickness to starting thickness at that point mid-point. In the biax geogrid (25), the junction mid-point is significantly thicker than the PD is less than about 80% of the ratio of finished thickness to starting thickness of the junction strand mid-point.

Abstract: The invention relates to a coextruded, transparent, biaxially oriented polyester film having at least three layers, with at least one base layer B, at least 80% by weight of which is composed of a thermoplastic polyester, where an outer layer has been applied to each surface of this base layer, and where at least one outer layer comprises particles, wherein the gloss of both surfaces of the film is above 170 the haze of the film is below 2.4% the planar orientation &Dgr;p of the film is below 0.162. the coefficient of friction (COF) is below 0.6. The invention further relates to the use of a film of this type, and also its production.

Abstract: The invention relates to a biaxially oriented polypropylene film which has good processing performance and, after it has been metallized or oxidically coated, is a very good barrier to oxygen, and which is composed of at least a base layer, wherein the planar orientation delta p of the film is greater than 0.0138.

Abstract: A multilayer sheet, which is particularly well adapted for use as as a label sleeve on carbonated beverage containers, includes first and second coextruded unfoamed layers of polymer compositions each consisting essentially of polyolefin, polystyrene and a compatibility agent. The polyolefin and polystyrene are in a weight ratio in the range of about 30/70 to 70/30, and the compatibility agent is in the amount of about 5% to 10% by total weight. A pigment in the amount of about 10% to 15% by total weight may be included in one or both of the coextruded layers. The polyolefin preferably is selected from the group consisting of polypropylene, polyethylene and mixtures thereof, and the compatibility agent preferably comprises a styrene-ethylene/butylene-styrene block copolymer. One of the unfoamed layers preferably is thicker and of higher strength than the other layer, while the other layer has a smooth uniform exterior surface.

Abstract: The disclosed biaxially oriented, multilayer polypropylene film comprises at least one base layer B, one interlayer Z and one top layer D and contains migrating additives. The film contains a maximum of 0.15% by weight of migrating additives, based on the total weight of the film. The multilayer film structure is produced by coextrusion and biaxial stretching followed by heat-setting and, optionally, corona treatment. The film is particularly useful in packaging and in laminates.

Abstract: A film production process having a film tentering step and a recovering step, characterized by detecting the side edge positions of the film running toward the recovering step, transferring the film running direction based on the detected information, and controlling the clamp start position of the film arriving at a tenter in the tentering step by clamp means, in the transverse direction of the film. A film production process having a film tentering step, characterized by controlling the clamp start position of a film arriving at a tenter by clamp means, in the range from 5 mm to 1,000 mm from the tip of the film in the longitudinal direction of the film.

Abstract: An economical method is disclosed for modifying the physical characteristics of a nonwoven fibrous web which involves passing the web between at least one pair of interengaged rolls to incrementally stretch the web, and then withdrawing the incrementally stretched web from between the rolls under tension. A web modified according to the disclosed method has advantageous elongation, extensibility and strength properties, as well as other desirable characteristics. In another aspect, a method is disclosed for forming a composite material by combining a modified nonwoven web with a polymeric film, or an elastic member, which may be liquid impervious yet breathable. In yet other aspect, a method is disclosed for forming a composite material by combining a modified web with a polymeric film which is rendered liquid-impervious yet breathable while the method is performed.

Abstract: The application discloses a sealable biaxially oriented polyester film having a base layer B at least 80% by weight of which is composed of a thermoplastic polyester, and having two outer layers A and C, wherein the outer layer A is composed of a polymer or of a mixture of polymers which comprises at least 40% by weight of ethylene 2,6-naphthalate units and up to 60% by weight of ethylene terephthalate units and/or units from cycloaliphatic or aromatic diols and/or dicarboxylic acids, and the opposite outer layer C is sealable and has a sealing initialization temperature of from about 100 to 200° C. The film has low atmospheric oxygen transmission. It is particularly suitable for packaging applications, specifically for packaging foods and other consumable items.

Abstract: A polyester film is disclosed, exhibiting a minimum value of not more than 0.15 with respect to the tan &dgr; value obtained at a frequency of 0.01 Hz within the range of 100 to 160° C., the tan &dgr; being determined in a tensile viscoelasticity measurement. A photographic support and photothermographic material using this polyester film are also disclosed, which exhibits superior dimensional stability even when subjected to thermal development at a high temperature and little roll set curl when used in a roll form.

Abstract: The invention relates to a biaxially oriented polyester film having at least two layers and which, together with good processing performance, after it has been metalized or has been coated with oxidic materials, is a very good gas or oxygen barrier, and which has been built up from at least one base layer and at least one outer layer applied to this base layer, where the film has a planar orientation &Dgr;p of greater than 0.165.

Abstract: The invention concerns an improved method of heating or tempering foils and an associated device including an arrangement for measuring the temperature, based on the following features: a separate arrangement is provided for heating the foil edges; the foil edge heating arrangement comprises an infrared radiator device (21) and a hot air heating device (29); and the infrared radiator device (21) and the hot air heating device (29) can be controlled or set at different heating output values.

Abstract: A battery separator is a polypropylene microporous membrane, made from a beta-nucleated precursor, and having an electrical resistance of less than 30 ohms-inches per mil, and a puncture strength of greater than 400 grams-force per mil. mil.

Abstract: Fibers and microfibrillated articles are provided by imparting fluid energy to at least one surface of a highly oriented, voided, melt-processed polymeric film. The fibers and microfibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.

Abstract: A method of biaxially stretching a polymeric film along an overbias stretch profile having the steps of (a) imparting a sufficiently high temperature to the film to allow a significant amount of biaxial stretch; and (b) biaxial tenter stretching the film to a final first direction stretch parameter and a final second direction stretch parameter, wherein at least 75% of the final first direction stretch parameter is attained before no more than 50% of the final second direction stretch parameter is attained, and wherein the final first direction stretch parameter is no greater than the final second direction stretch parameter.

Abstract: The present invention relates to a multi-layer packaging film comprising an intermediate layer having at least one outer layer on both surfaces of the intermediate layer, and having the thickness of not more than 40 &mgr;m, said outer layer comprising a polyolefin resin, said intermediate layer comprising a polytetramethylene terephthalate resin obtained by copolymerizing polytetramethylene oxide glycol having a number-average molecular weight of 300 to 5,000 and having an intrinsic viscosity of 0.7 to 2.0, a melting point of 200 to 228° C. and a crystallization temperature of not higher than 180° C., and the thickness of said intermediate layer being 20 to 80% of the thickness of the multi-layer film.

Abstract: There is disclosed a process for inline producing a biaxially oriented releasing film by consecutively orienting a non oriented film (polyethylene terephthalate or polypropylene) in the machine or transverse direction one by one which comprises coating at least one side of a film in a state prior to biaxial orientation with an addition reaction type silicone based releasing agent (e.g. solvent type), preferably incorporated with a photosensitizer; biaxially orienting the film; thereafter heat annealing the same; and subsequently performing ultraviolet ray irradiation. The process enables easy production of the releasing film which is excellent in releasability, non-migration property of silicone, and productivity, and which is well suited for use in the production of pressure sensitive adhesive labels and tapes, ceramic green sheets, synthetic leather, etc.

Abstract: A biaxially oriented polyolefin film having more than one layer and made from a base layer and from at least one outer layer. The base layer include a fatty amide and the outer layer include at least 80% by weight of a linear olefin polymer. The film is suitable, for example, for producing a film laminate by melt extrusion of a polyethylene layer.

Abstract: This invention relates to a process for producing an invisible and writable biaxially oriented polypropylene (BOPP) raw processing film of thickness between 20 to 60 &mgr;m. More particularly, this invention relates to a process for producing a three-layers biaxially oriented PP synthetic raw processing film by means of three-layers co-extrusion, wherein two different PP resin compositions are separately extruded by one primary and two secondary extruders first, and then are co-flowed by a same T-die through cooling molding to form a three layers coating sheet, and through biaxial orientation, corona treatment and winding to form three layers co-extrusion synthetic film of thickness 20-60 &mgr;m. The three layers structure of said three layers co-extrusion synthetic film can be made in the form of invisible and writable layer/intermediate resin layer/backing adhesive resin layer, which can be used in industrial application and stationery application after winding finishing.

Abstract: Use of at least partly cross-linked polyolefin plastic, which is oriented biaxially, as material for pressure pipes, is described. The pressure pipe is produced by extrusion with subsequent axial and peripheral orientation of the pipe, the pipe being at least partly cross-linked before the biaxial orientation. Preferably, the pipe is cross-linked to about 20-50% before orientation. By the at least partial cross-linking before orientation, this can be carried out at temperatures above the crystalline melting point of the plastic material.

Abstract: Polyolefin/filler breathable films may be produced by machine or transverse direction orientation using interdigitating grooved rollers. Biaxial orientation to similarly produce breathable films may be accomplished by the same method. By heating the rollers, the breathability of the film is increased without increasing the depth of engagement of the interdigitating rollers.

Abstract: A biaxially-oriented polyester film includes at least two layers and at least one outermost layer is composed of a polyester having a rigid amorphous content of about 10 to 55%. The biaxially-oriented polyester film has a longitudinal Young's modulus of at least about 4.5 GPa. The biaxially-oriented polyester film is suitable for high-density magnetic recording media, such as digital video tapes and high-density data recording tapes.

Abstract: A biaxially oriented polyester film which has good thickness nonuniformity in both longitudinal and transverse directions, uniform physical properties in a transverse direction and high strength in a longitudinal direction. This film has such characteristic properties that (a) an F-5 value in a longitudinal direction of 13 kg/mm2 or more, (b) a thickness nonuniformity in each of both longitudinal and transverse directions of 8% or less, and (c) a difference in the heat shrinkage factor of 0.02 to 0.2% per 1 m in a transverse direction, said heat shrinkage factor being measured at 105° C. in the longitudinal direction.

Abstract: A method of biaxially stretching a polymeric film according to an overbias or overstretch stretch profile to a final first direction stretch parameter and a final second direction stretch parameter to provide a film having uniform properties. First, a sufficiently high temperature is imparted to the film to allow a significant amount of biaxial stretch. The film is then biaxially tenter stretched to a peak first direction stretch parameter that is at least 1.3 times the final first direction stretch parameter wherein the final first direction stretch parameter is no larger than the final second direction stretch parameter. Finally, the film is retracted in the first direction from the peak first direction stretch parameter to the final first direction stretch parameter to produce a film having uniformity of properties in the first direction.

Abstract: A continuous process and apparatus for producing oriented plastic tube comprising the steps of extrusion, temperature conditioning, diametrical expansion and cooling, characterized by the step of inducing axial draw of the tube between first and second haul-off means located upstream of the expansion step.

Abstract: A film includes at least one layer comprising a blend of an ethylene polymer having a density of at least 0.925 grams per cubic centimeter, and an ethylene copolymer selected from the group consisting of ethylene/ester copolymer, and ethylene/alpha-olefin copolymer. The film is preferably substantially free from linear low density polyethylene. The film can be a monolayer or multilayer film, and can comprises a core layer comprising an ethylene polymer having a density of at least 0.925 grams per cubic centimeter; and one or more outer layers with the above described blend. At least one intermediate layer comprising an ethylene copolymer having a density of less than 0.925 grams per cubic centimeter can also be included. The film preferably has a thickness of less than 0.60 mils; a shrink force of less than 0.35 pounds in the longitudinal direction, and less than 0.

Abstract: A biaxially oriented polyester film for capacitors, wherein the polyester film comprises a polyester containing 80 mol % or more polyethylene terephthalate units, has at least one coating layer composed of water soluble or water dispersible resin, and has a heat shrinkage stress satisfying the following formulae (1) to (3): S150 < 200 g/mm2 S150-S120 < 100 g/mm2 Smax < 500 g/mm2 wherein S150 and S120 represent the values of heat shrinkage stress per unit cross section area of the film at 150° C. and 120° C., respectively, and Smax represents the maximum value of the heat shrinkage stress at a temperature within the rage of not less than 150° C. and not more than the melting point of the film.

Abstract: The present invention relates to a single or multilayer biaxially oriented film having a thickness of ≦12 &mgr;m, in which Ts (TD) is ≧160° C., S 200 (TD) is ≦5%, S 200 (MD) is 2-5%, the shrinkage force ratio Ns 220/Ns 160 is ≧4.5; the film fixing peak is ≧210° C.; the film density is 1.39-1.41 g/cm3, and Ts (TD) is the temperature at which the transverse shrinkage begins, S 200 (TD) is the shrinkage in the transverse direction (in %) at 200° C., S 200 (MD) is the shrinkage in the machine direction (in %) at 200° C., Ns 220 is the shrinkage force (in N) at 220° C. and Ns 160 is the shrinkage force (in N) at 160° C. in the transverse direction. The invention also relates to a method for forming the film.

Abstract: Multilayer laminates including films, sheets, preforms, containers and other articles having at least one wholly aromatic, amorphous, stretchable liquid crystalline polymer layer with at least one non-liquid crystalline thermoplastic polyester layer are provided as well as methods for producing and stretching the multilayer articles. The laminates are suitable for thermoforming and stretch blow molding applications and may be stretched to at least 100 percent elongation at temperatures below 200° C. and at high total draw ratios without fractures or tears. Containers suitable for food or beverage products may be produced from the laminates.

Abstract: Polyolefin/filler breathable films may be produced by machine or transverse direction orientation using interdigitating grooved rollers. Biaxial orientation to similarly produce breathable films may be accomplished by the same method. By heating the rollers, the breathability of the film is increased without increasing the depth of engagement of the interdigitating rollers.

Abstract: The invention relates to a single-layer biaxially oriented polyester film which, together with good processing performance, after it has been metalized or has been coated with oxidic materials, has very good gas or oxygen barrier properties, and which has been built up from one base layer, where the film has a planar orientation &Dgr;p of greater than 0.166. For at least one surface of the film, the number N of elevations per mm2, the height n in &mgr;m, and the diameter d in &mgr;m of the elevations are linked by the following equations: - 1 - 3.7 * log ⁢   ⁢ h / μm < log · N / mm 2 < 2.48 - 2.

Abstract: It is an object of the present invention to provide a microporous polyolefin membrane, high in elongation and porosity, low in shrinkage, and capable of improving battery characteristics, safety and productivity, when used for battery separators. The microporous polyolefin membrane of the present invention comprises (A) an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×105 or more, or (B) a composition containing an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5×105 or more, and having a porosity of 45 to 95%, elongation at break of 300% or more, bubble point exceeding 980 KPa and thermal shrinkage in the TD direction of 3% or less. The present invention also provides a method for producing the above microporous polyolefin membrane.

Abstract: A polyolefin shaped article having high strength and high modulus is efficiently manufactured without a need to accompany a process of removing a flow modifier or the like. A method is characterized as including the steps of melt forming a composition principally containing 100 parts by weight of high-density polyolefin, such as high-density polyethylene, and 1-30 parts by weight of a polymerizable monomer or oligomer having a preferred affinity for the high-density polyolefin into a sheet or film, calendering and stretching the sheet or film, and then polymerizing the polymerizable monomer or oligomer incorporated in the sheet or film.