Abstract: A battery separator includes a polyolefin microporous membrane and a porous layer placed on at least one surface of the polyolefin microporous membrane. The polyolefin microporous membrane has a variation range of an F25 value in a longitudinal direction of 1 MPa or less. The F25 value indicates a value obtained by dividing a load value measured at 25% elongation of a specimen with use of a tensile tester by a cross-sectional area of the specimen. The porous layer contains a fluorine-based resin and an inorganic particle and has an average thickness T(ave) of 1 to 5 ?m.

Abstract: A polyolefin microporous membrane has a variation range of F25 value in a longitudinal direction of 1 MPa or less; a thickness of 3 ?m or more and less than 7 ?m; and a length of 1,000 m or more (wherein the F25 value is a value obtained by measuring a load value applied to a test specimen when the test specimen is stretched by 25% using a tensile tester; and dividing the load value by a value of a cross-sectional area of a test specimen).

Abstract: A polyolefin microporous membrane is suitable to provide thereon a porous layer having little variation in thickness, which has a fluctuation range of F25 value in the length direction of 1 MPa or less, and which has a length of 1,000 m or more (wherein the F25 value refers to a value obtained by: measuring a load value applied to a test specimen when the test specimen is stretched by 25% using a tensile tester; and dividing the load value by the value of the cross-sectional area of the test specimen).

Abstract: A polyolefin microporous membrane is suitable to provide thereon a porous layer having little variation in thickness, which has a fluctuation range of F25 value in the length direction of 1 MPa or less, and which has a length of 1,000 m or more (wherein the F25 value refers to a value obtained by: measuring a load value applied to a test specimen when the test specimen is stretched by 25% using a tensile tester; and dividing the load value by the value of the cross-sectional area of the test specimen).

Abstract: A battery separator includes a polyolefin microporous membrane having a width of 100 mm or more, and a porous layer laminated on at least one surface of the polyolefin microporous membrane. The polyolefin microporous membrane has a variation range of an F25 value in a width direction of 1 MPa or less, and the F25 value indicates a value obtained by dividing a load value measured at 25% elongation of a specimen with use of a tensile tester by a cross-sectional area of the specimen. The porous layer contains a fluorine-based resin and an inorganic particle.

Abstract: A polyolefin microporous membrane on which a porous layer has little fluctuations in thickness and a separator for batteries can adapt to the increase in capacity of a battery. A polyolefin microporous membrane having a range of fluctuation in a F25 value in the width direction of 1 MPa or less, a thickness of 3 ?m or more and less than 7 ?m and a width of 100 mm or more (wherein the term “F25 value” refers to a value produced by dividing the value of a load applied to a test specimen upon the stretching of the test specimen at a stretching ratio of 25% using a tension tester by the value of a cross-sectional area of the test specimen).

Abstract: The present invention provides a microporous membrane having an excellent balance of temperature characteristics, shrinkage characteristics, permeability, and strength, and thereby realizes a separator for a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte secondary battery, having excellent performance and excellent safety. A polyolefin microporous membrane having; a temperature difference not less than 7.2° C. between a shutdown shrinkage temperature and a maximum shrinkage temperature in a TD measured by TMA; a shrinkage rate difference less than 25% between a shutdown shrinkage rate and a maximum shrinkage rate in the TD; a pin puncture strength at a membrane thickness of 16 ?m being not less than 400 gf; and a ratio of pin puncture strength to air permeation resistance at a membrane thickness of 16 ?m being from 2.0 to 4.0 (gf/(sec/100 cc)).

Abstract: A polyolefin microporous membrane is disclosed. The membrane has a width of not less than 100 mm, and a variation range of an F25 value in a width direction is not greater than 1 MPa. The F25 value is a value obtained by dividing a load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile testing machine by a cross-sectional area of the sample.

Abstract: A multi-layer polyolefin porous membrane is disclosed. The membrane includes first and second layers, and a plurality of protrusions including polyolefin. The protrusions have a protrusion width (W) satisfying 5 ?m?W?50 ?m and have a protrusion height (H) satisfying 0.5 ?m?H. The protrusions are randomly disposed on a first side of the membrane, and the protrusions are disposed with a density of not less than 3 protrusions/cm2 and not greater than 200 protrusions/cm2. A meltdown temperature of the membrane is not lower than 165° C., an air permeation resistance of the membrane is not greater than 300 sec/100 cc Air, and a thickness of the membrane is not greater than 20 ?m.

Abstract: A battery separator includes a polyolefin microporous membrane and a porous layer placed on at least one surface of the polyolefin microporous membrane. The polyolefin microporous membrane has a variation range of an F25 value in a longitudinal direction of 1 MPa or less. The F25 value indicates a value obtained by dividing a load value measured at 25% elongation of a specimen with use of a tensile tester by a cross-sectional area of the specimen. The porous layer contains a fluorine-based resin and an inorganic particle and has an average thickness T(ave) of 1 to 5 ?m.

Abstract: A polyolefin microporous membrane has a variation range of F25 value in a longitudinal direction of 1 MPa or less; a thickness of 3 ?m or more and less than 7 ?m; and a length of 1,000 m or more (wherein the F25 value is a value obtained by measuring a load value applied to a test specimen when the test specimen is stretched by 25% using a tensile tester; and dividing the load value by a value of a cross-sectional area of a test specimen).

Abstract: A laminated polyolefin microporous membrane is disclosed. The laminated polyolefin microporous membrane includes a first polyolefin microporous membrane, and a second polyolefin microporous membrane. A shutdown temperature of the laminated polyolefin microporous membrane is from 128° C. to 135° C., an air permeation resistance increase rate from 30° C. to 105° C. per 20 ?m of thickness of the laminated polyolefin microporous membrane is less than 1.5 sec/100 cc Air/° C., and a variation range in an F25 value of the laminated polyolefin microporous membrane in a longitudinal direction is not greater than 1 MPa. The F25 value represents a value determined by dividing the load at 25% elongation of a sample of the laminated polyolefin microporous membrane as measured with a tensile tester by the cross-sectional area of the sample polyolefin microporous membrane.

Abstract: A battery separator includes a polyolefin microporous membrane having a width of 100 mm or more, and a porous layer laminated on at least one surface of the polyolefin microporous membrane. The polyolefin microporous membrane has a variation range of an F25 value in a width direction of 1 MPa or less, and the F25 value indicates a value obtained by dividing a load value measured at 25% elongation of a specimen with use of a tensile tester by a cross-sectional area of the specimen. The porous layer contains a fluorine-based resin and an inorganic particle.

Abstract: A polyolefin microporous membrane is disclosed. The membrane includes at least one microporous membrane layer, where the microporous membrane layer has an air permeability between about 100 sec/100 cc and about 220 sec/100 cc, a pin puncture strength of at least 550 gf, and a crystallization half time t1/2 of from 10 to 35 minutes when subjected to isothermal crystallization at 117° C. The air permeability and the pin puncture strength are normalized to a thickness of 16 ?m.

Abstract: Provided is a biaxially stretched polypropylene film for capacitors which has high withstand voltage characteristics when used as a dielectric for capacitors and which has highly suitable processability into elements. The biaxially stretched polypropylene film for capacitors has projections on both surfaces and has a thickness (t1, ?m) of 4-20 ?m. When one of the surfaces is expressed by surface A and the other by surface B, all of the following relationships are satisfied. 800?SRzB?1,300 (nm) 0.1?SRzA/SRzB?0.8 PBmin?100 (nm) PBmax?1,500 (nm) 0.4?PB450-750/PB?0.7.

Abstract: A method of producing a microporous plastic film includes kneading a diluent and a polyolefin resin with an extruder; discharging the polyolefin resin kneaded with the diluent from a die lip in a sheet shape; cooling and solidifying the sheet discharged from the die lip on a drum; reheating and drawing the solidified sheet with a plurality of rollers in a sheet conveying direction; cooling the sheet drawn in the sheet conveying direction; gripping both ends of the sheet with clips; introducing the sheet into a tenter; and washing the diluent out to prepare a uniaxially or biaxially oriented microporous plastic film, wherein the sheet is drawn in two or more sections having substantively the same draw ratio between the rollers.

Abstract: A method of producing a microporous plastic film includes kneading a diluent and a polyolefin resin with an extruder; discharging the polyolefin resin kneaded with the diluent from a die lip in a sheet shape; cooling and solidifying the sheet discharged from the die lip on one or plurality of cooling drums; reheating and drawing the solidified sheet with a plurality of rollers in a sheet conveying direction; cooling the sheet drawn in the sheet conveying direction; gripping both ends of the sheet with clips; introducing the sheet into a tenter; washing the diluent out to prepare a uniaxially or biaxially oriented microporous plastic film; and driving a nip roller with a motor, the nip roller pressing a sheet interposing between the nip roller and at least one of the rollers.

Abstract: A method of producing a microporous plastic film including kneading a diluent and a polyolefin resin with an extruder; discharging the polyolefin resin kneaded with the diluent from a die lip in a sheet shape; cooling and solidifying the sheet discharged from the die lip on a drum; reheating and drawing the solidified sheet with a plurality of rollers in a sheet conveying direction; cooling the sheet drawn in the sheet conveying direction; gripping both ends of the sheet with clips; introducing the sheet into a tenter; washing the diluent out to prepare a uniaxially or biaxially oriented microporous plastic film; and pressing the sheet interposing between a nip roller having a surface coated with a rubber and a driving roller driven by a motor upstream from a roller at the most downstream side among the rollers.

Abstract: A method produces a microporous plastic film including kneading a diluent and a polyolefin resin with an extruder, discharging the diluent-kneaded polymer from a die in a sheet form, cooling and solidifying the sheet discharged from the die on a drum, then reheating the solidified sheet, drawing the same in a sheet conveying direction with a plurality of rollers, cooling the sheet drawn in the sheet conveying direction, then gripping both ends of the sheet with clips, introducing the sheet into a tenter, and then cleaning the diluent, wherein: at least two rollers among the plurality of rollers are each driven by a motor; the surface of each of at least two rollers (A, B) among the rollers driven by the motor is brought into contact with a surface of the sheet on the opposite side from the surface that has come into contact with the drum; and the rotation speed of the rollers (A, B) is controlled such that the sheet can be drawn substantially between these two rollers.

Abstract: A method of producing a microporous film includes kneading a diluent and a polyolefin resin with an extruder; discharging the polyolefin resin kneaded with the diluent from a die lip in a sheet shape; cooling and solidifying the sheet discharged from the die lip on a drum; reheating and drawing the solidified sheet with a plurality of rollers in a sheet conveying direction; cooling the sheet drawn in the sheet conveying direction; gripping both ends of the sheet with clips; introducing the sheet into a tenter; washing the diluent out to prepare a uniaxially or biaxially oriented microporous plastic film, wherein drawing is performed by a draw ratio greatest among drawing in the sheet conveying direction, and a ratio of travelling speed of the clip of the tenter at a most upstream side in the sheet conveying direction to a peripheral speed of the roller (B) is ?3% to +3%.