Abstract: Provided is a microporous polyolefin composite film with a thermally stable porous layer at high temperature, particularly, to the microporous polyolefin composite film in which the thermally stable porous layer at high temperature, which contains organic or inorganic particles and heat-resistant polymer having aromatic ring in main chain and also having a melting temperature or a glass transition temperature of 170 to 500° C., is formed on one surface or both surfaces of a polyolefin microporous film by a phase separation, wherein the composite film with the porous layer has a permeability of 1.5×10?5 to 20.0×10?5 Darcy, a meltdown temperature of 160 to 300° C., a MD/TD shrinkage of 1 to 40% at a temperature of 150° C. for 60 minutes.

Abstract: Provided is a microporous polyolefin composite film with a thermally stable porous layer at high temperature, particularly, to the microporous polyolefin composite film in which the thermally stable porous layer at high temperature, which contains organic or inorganic particles and heat-resistant polymer having aromatic ring in main chain and also having a melting temperature or a glass transition temperature of 170 to 500° C., is formed on one surface or both surfaces of a polyolefin microporous film by a phase separation, wherein the composite film with the porous layer has a permeability of 1.5×10?5 to 20.0×10?5 Darcy, a meltdown temperature of 160 to 300° C., a MD/TD shrinkage of 1 to 40% at a temperature of 150° C. for 60 minutes.

Abstract: Provided is a microporous organic/ inorganic composite coated layer comprising a heat resistant resin and inorganic particles, formed on at least one side of microporous polyethylene. The microporous polyethylene composite film is characterized by sufficient permeability and heat resistance at the same time, of which the permeability (Gurley) of overall composite film including a coated layer is not more than 300 sec; shrinkage after 150° C. for 1 hour is 0-3% in both MD/TD directions; maximum shrinkage in TMA is not more than 3%, and TMA meldown temperature is 145-200° C. The microporous polyethylene composite film formed by means of the coated layer possesses stability at high temperature as well as excellent permeability, thereby ensuring reliability and efficiency of a battery at the same time. A separator which conforms to high power/high capacity can be provided thereby.

Abstract: Provided is a method of manufacturing a microporous polyolefin composite film with a thermally stable porous layer at high temperature, particularly, to a method of manufacturing a microporous polyolefin composite film with a thermally stable porous layer at high temperature, comprising preparing a polyolefin microporous film using a composition containing a polyolefin resin; coating a solution, in which a high heat-resistant resin is dissolved in a solvent, on one surface or both surfaces of the polyolefin microporous film; phase-separating the polyolefin microporous film coated with the solution by contacting with a nonsolvent after the coating; and drying the polyolefin microporous film so as to remove the solvent and nonsolvent remained after the phase-separating, and thus forming the thermally stable layer at high temperature.

Abstract: Provided is a microporous polyolefin composite film with a thermally stable porous layer at high temperature, particularly, to the microporous polyolefin composite film in which the thermally stable porous layer at high temperature, which contains organic or inorganic particles and heat-resistant polymer having aromatic ring in main chain and also having a melting temperature or a glass transition temperature of 170 to 500° C., is formed on one surface or both surfaces of a polyolefin microporous film by a phase separation, wherein the composite film with the porous layer has a permeability of 1.5×105 to 20.O×IO 5 Darcy, a meltdown temperature of 160 to 300° C., a MD/TD shrinkage of 1 to 40% at a temperature of 15O° C. for 60 minutes.