Patent ID: 8617645
Filing Date: 2013-12-31
Classification: B01D,H01M,Y02E

Abstract:
1. A preparation method of a multi-component composite film comprising: a porous polymeric support layer film having a pore size ranging from 0.001 to 10 μm; and a porous gellable polymer layer having a pore size of at most 10 μm which is formed on one side or both sides of the porous polymeric support layer film, wherein the pore size of the porous polymeric support layer film is different than the pore size of the porous gellable polymer layer and wherein the porous polymeric support layer film and the porous gellable polymer layer are joined directly to each other, which comprises: preparing a nonporous polymeric support layer film; dissolving a gellable polymer in a solvent in order to prepare a gellable polymer solution; forming a porous gellable polymer layer joined directly on one side or both sides of the nonporous polymeric support layer film by coating the gellable polymer solution on the nonporous polymeric support layer film to form a gellable polymer layer, and drying the coated film to form a porous gellable polymer layer, in order to prepare a multiple layer; and stretching and heat-setting the multiple layer to prepare a multi-component composite film comprising the porous polymeric support layer film and the porous gellable polymer layer wherein the pore size of the porous polymeric support layer film is different than the pore size of the porous gellable polymer layer and wherein the porous polymeric support layer film and the porous gellable polymer layer are joined directly to each other, wherein pores are formed on the polymeric support layer film by the stretching step, and wherein pores are formed on the gellable polymer layer by a phase transition process including the coating and drying steps, and by the stretching step, wherein a material of the polymeric support layer film is at least one selected from the group consisting of high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, high crystalline polypropylene, polyethylene-propylene copolymer, polyethylene-butylene copolymer, polyethylene-hexene copolymer, polyethylene-octene copolymer, polystyrene-butylene-styrene copolymer, polystyrene-ethylene-butylene-styrene copolymer, polystyrene, polyphenylene oxide, polysulfone, polycarbonate, polyester, polyamide, polyurethane, polyacrylate, polyvinylidene chloride, polyvinylidene fluoride, polysiloxane, polyolefin ionomer, polymethyl pentene, hydrogenated oligocyclopentadiene (HOCP), and a mixture thereof or a derivative thereof, the gellable polymer is at least one selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride-chlorotrifluoroethylene copolymer, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, polypropylene oxide, polybutylene oxide, polyurethane, polyacrylonitrile, polyacrylate, polymethyl methacrylate, polyacrylic acid, polyamide, polyacrylamide, polyvinyl acetate, polyvinylpyrrolidone, polytetraethylene glycol diacrylate, polysulfone, polyphenylene oxide, polycarbonate, polyester, polyvinylidene chloride, polysiloxane, polyolefin ionomer, and a copolymer thereof or a derivative thereof, the gellable polymer solution is prepared by adding at least one lithium salt selected from the group consisting of LiSCN, LiClO the thickness of the porous polymeric support layer film ranges from 1 to 50 μm, and the thickness of the porous gellable polymer layer ranges from 0.01 to 25 μm, an interfacial adhesive strength measured by the method according to JIS Z 0237 between the porous polymeric support layer film and the porous gellable polymer layer is from 150 to 250 gf, and the air permeability of the multi-component composite film is from 100 to 20,000 sec/100 cc.