Abstract: Disclosed is a polyethylene porous film having an average pore diameter of 200 nm or less, a specific surface area of 50 m2/g or more, and a porosity of 15% or more, each of which is measured by a mercury intrusion method at room temperature, the polyethylene porous film being obtained by forming pores only by drawing a film containing an ultrahigh molecular weight polyethylene having a viscosity average molecular weight of from 1 million to 15 million and a polyethylene having a weight average molecular weight of from 10,000 to 800,000 at a mass ratio of from 50:50 to 99:1. The polyethylene porous film is produced by molding a film using a mixture of the ultrahigh weight polyethylene and the polyethylene having a weight average molecular weight of from 10,000 to 800,000, biaxially drawing the film, then heat-treating and redrawing the film to form pores in the film.

Abstract: A method of manufacturing a PTFE stretched film that has higher tensile strength at its breaking point. In the method, a resin composition is obtained by mixing an emulsion of PTFE (A) with a number average molecular weight of 5×106 or more and an emulsion of PTFE (B) with a number average molecular weight of 1×106 to 4×106 so that the solid content ratio (A/B) of the PTFE (A) and the PTFE (B) is 99/1 to 10/90. The mixed emulsion is subjected to compression molding in a melted state under a reduced-pressure atmosphere to obtain a film.

Abstract: Disclosed is a polyethylene porous film having an average pore diameter of 200 nm or less, a specific surface area of 50 m2/g or more, and a porosity of 15% or more, each of which is measured by a mercury intrusion method at room temperature, the polyethylene porous film being obtained by forming pores only by drawing a film containing an ultrahigh molecular weight polyethylene having a viscosity average molecular weight of from 1 million to 15 million and a polyethylene having a weight average molecular weight of from 10,000 to 800,000 at a mass ratio of from 50:50 to 99:1. The polyethylene porous film is produced by molding a film using a mixture of the ultrahigh weight polyethylene and the polyethylene having a weight average molecular weight of from 10,000 to 800,000, biaxially drawing the film, then heat-treating and redrawing the film to form pores in the film.

Abstract: Disclosed is a method for producing a ultra high molecular weight polyethylene film, which comprises: a step of forming a film using a ultra high molecular weight polyethylene material; a step of biaxially drawing the film obtained in the step in the x-axis direction and in the y-axis direction at a temperature not less than the melting point of the ultra high molecular weight polyethylene material; and the step of shrinking the film along at least one of the x-axis direction and y-axis direction. By this method, a ultra high molecular weight polyethylene film having high tensile strength at break, high tear strength and excellent uniformity can be efficiently produced at low cost.

Abstract: The present invention provides a method for producing stereo complex crystals of polylactic acid, with which a polylactic acid having excellent heat resistance and containing stereo complex crystals at a high ratio can be efficiently produced, the method including: a step of dissolving in a solvent a block copolymer, which includes polylactic acid containing an L-lactic acid unit or poly lactic acid containing a D-lactic acid unit together with at least one kind of an organic polymer having a different structure from that of polylactic acid, and a polylactic acid homopolymer containing a D-lactic acid unit or a polylactic acid homopolymer containing an L-lactic acid unit, the lactic acid unit being an optical isomer that is not contained in the block copolymer, to prepare a polymer mixture solution; and a step of removing the solvent from the polymer mixture solution.

Abstract: A method for producing an ultra-high-molecular-weight polyethylene porous membrane, including: a step of molding a film using an ultra-high-molecular-weight polyethylene raw material; a step of biaxially stretching the obtained film in X-axis and Y-axis directions at a temperature of from a melting point of the film to 180° C.; and a pore-forming step of stretching the stretched film along at least one axis of the X-axis and Y-axis at from 142° C. to 170° C. Alternatively, a method for producing an ultra-high-molecular-weight polyethylene film, including: a step of molding a film by two steps of press-molding and roll-molding using an ultra-high-molecular-weight polyethylene raw material; and a step of biaxially stretching the film obtained in the above step, in X-axis and Y-axis directions at a temperature of from a melting point of the film to 180° C.

Abstract: A method for producing an ultra-high-molecular-weight polyethylene porous membrane, including: a step of molding a film using an ultra-high-molecular-weight polyethylene raw material; a step of biaxially stretching the obtained film in X-axis and Y-axis directions at a temperature of from a melting point of the film to 180° C.; and a pore-forming step of stretching the stretched film along at least one axis of the X-axis and Y-axis at from 142° C. to 170° C. Alternatively, a method for producing an ultra-high-molecular-weight polyethylene film, including: a step of molding a film by two steps of press-molding and roll-molding using an ultra-high-molecular-weight polyethylene raw material; and a step of biaxially stretching the film obtained in the above step, in X-axis and Y-axis directions at a temperature of from a melting point of the film to 180° C.

Abstract: A method of manufacturing a PTFE stretched film that has higher tensile strength at its breaking point. In the method, a resin composition is obtained by mixing an emulsion of PTFE (A) with a number average molecular weight of 5×106 or more and an emulsion of PTFE (B) with a number average molecular weight of 1×106 to 4×106 so that the solid content ratio (A/B) of the PTFE (A) and the PTFE (B) is 99/1 to 10/90. The mixed emulsion is subjected to compression molding in a melted state under a reduced-pressure atmosphere to obtain a film.

Abstract: The present invention provides a method for producing stereo complex crystals of polylactic acid, with which a polylactic acid having excellent heat resistance and containing stereo complex crystals at a high ratio can be efficiently produced, the method including: a step of dissolving in a solvent a block copolymer, which includes polylactic acid containing an L-lactic acid unit or poly lactic acid containing a D-lactic acid unit together with at least one kind of an organic polymer having a different structure from that of polylactic acid, and a polylactic acid homopolymer containing a D-lactic acid unit or a polylactic acid homopolymer containing an L-lactic acid unit, the lactic acid unit being an optical isomer that is not contained in the block copolymer, to prepare a polymer mixture solution; and a step of removing the solvent from the polymer mixture solution.

Abstract: Disclosed is a method for producing a ultra high molecular weight polyethylene film, which comprises: a step of forming a film using a ultra high molecular weight polyethylene material; a step of biaxially drawing the film obtained in the step in the x-axis direction and in the y-axis direction at a temperature not less than the melting point of the ultra high molecular weight polyethylene material; and the step of shrinking the film along at least one of the x-axis direction and y-axis direction. By this method, a ultra high molecular weight polyethylene film having high tensile strength at break, high tear strength and excellent uniformity can be efficiently produced at low cost.