The present invention relates to a method for manufacturing a polyimide-powder composite separator using water and a polyimide-powder composite separator manufactured by the method, and is environmentally friendly since an organic solvent is not used in the overall process of manufacturing the composite separator and has advantageous effects in terms of time, cost, and manufacturing process since a high temperature/high pressure environment is not required.

A polymer solution is created by mixing an olefin-based resin and a solvent in a pressure vessel. A high-pressure fluid of carbon dioxide is created. Temperature of the high-pressure fluid is adjusted. A mixed fluid is created by mixing the high-pressure fluid of which the temperature is adjusted and the polymer solution in the pressure vessel. Cooling of the mixed fluid causes phase separation of the mixed fluid to occur. After phase separation, pressure in the pressure vessel is released, and the solvent and the carbon dioxide vaporize. The vaporizing of the solvent and the carbon dioxide creates a porous medium of olefin-based resin.

A separator for a rechargeable battery includes a porous substrate and a heat resistance layer on at least one surface of the porous substrate. The heat resistance layer includes an acryl-based copolymer, an alkali metal, and a filler. The acryl-based copolymer includes a unit derived from (meth)acrylate or (meth)acrylic acid, a cyano group-containing unit, and a sulfonate group-containing unit.

Disclosed is a separator for an electrochemical device including a porous polymer film, and a porous coating layer including at least one type of particles of inorganic particles and organic particles and binder polymer, the porous coating layer formed on one surface or both surfaces of the porous polymer film, wherein the porous polymer film has a structure in which multiple fibrils arranged parallel to the surface of the film are stacked in layers, and a diameter of the fibril disposed at the side of one surface of the film where the porous coating layer is formed is smaller than a diameter of the fibril disposed at a central part in a thickness-wise direction of the film, and an electrochemical device comprising the same.

Disclosed is a method for preparing a three-layer-co-extruded diaphragm of a lithium-ion battery, falling into lithium-ion battery diaphragm technical field. The annealing box used comprises: box body, motor and sealing over, with uniformly-arranged heating plates fixedly connected to inner surface of the box body, a driving shaft arranged horizontally within the box body in front-back direction, a first and second driven shafts arranged on the left and right sides of the driving shaft correspondingly within the box body, an interlayer film coiling connected between the driving shaft and the first driven shaft within the box body horizontally; a diaphragm coiling connected between the driving shaft and the second driven shaft within the box body slantwise. Controllable annealing temperature and insulation from external environment avoid influence of external environment on diaphragm and ensure uniform heating of diaphragm. It produces a diaphragm of stable quality and is convenient to be mass-produced.

Provided are a heat-resistant synthetic resin microporous film that has both good heat resistance and good mechanical strength and exhibits a suppressed decrease in mechanical strength over time, and a method for producing the heat-resistant synthetic resin microporous film. The heat-resistant synthetic resin microporous film of the present invention includes a synthetic resin microporous film, and a coating layer formed on at least part of the surface of the synthetic resin microporous film and containing a polymer of a polymerizable compound having two or more radically polymerizable functional groups per molecule. The maximum thermal shrinkage rate of the heat-resistant synthetic resin microporous film when heated from 25° C. to 180° C. at a temperature rising rate of 5° C./min is 15% or less. The piercing strength thereof is 0.6 N or more. The rate of retention of the piercing strength after heating at 70° C. for 168 hours is 85% or more.

Provided is a method for producing a binder composition for an electrochemical device that can sufficiently inhibit importation of contaminants into an electrochemical device when used in production of the electrochemical device. The method for producing a binder composition for an electrochemical device includes filling, into a container, a binder composition for an electrochemical device that contains a binder, wherein the container is a container made of a resin and shaped in a clean environment in which the number of particles of 0.5 μm in diameter is no greater than 100,000 particles per 1 ft.sup.3.

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).

A method for film production includes the steps of obtaining information on the position of a defect (D) in a separator (12a) and providing marks (LA, LB) at the respective positions in the vicinity of the defect (D), the marks indicating the position of the defect.

An ultrasonic bonding device includes a processing member, a biasing member, a first moving unit and a second moving unit. The biasing member biases a pair of separators to the ultrasonic horn. A first moving unit separates the ultrasonic horn and the biasing member from each other with respect to a transport path of the separators. A second moving unit moves the separators and positions a bonding portion of the separators between the ultrasonic horn and the biasing member. The first moving unit has a coupling cam rotationally driven by a driving unit, a first connecting portion coupling the coupling cam and the processing member, and a second connecting portion coupling the coupling cam and the biasing member, and separating the processing member and the biasing member from each other with respect to the transport path by rotation of the coupling cam.