# US 2013/0157035 A1 · Method for Producing Ultra-High-Molecular-Weight Polyethylene Porous Membrane, Method for Producing Ultra-High-Molecular-Weight Polytheylene Film, and Porous Membrane and Film Obtained By These Methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0157035 A1 - Document ID: US20130157035A1 - Status: Published application - Kind: A1 - Application number: 13/819,406 - Filed: 2011-08-31 - Published: 2013-06-20 - Earliest claimed: 2010-08-31 - Assignees: National University Corporation Gumna University - Inventors: Hiroki Uehara; Takeshi Yamanobe - Web page: https://patentgrep.com/patent/US20130157035A1 ## CPC - B29D 7/01: Films or sheets - B29C 55/005: {characterised by the choice of materials} - B29C 55/143: {firstly parallel to the direction of feed and then transversely thereto} - B29C 55/18: by squeezing between surfaces, e.g. rollers - C08J 5/18: Manufacture of films or sheets - B29K 2023/0683: {UHMWPE, i.e. ultra high molecular weight polyethylene} - B29K 2105/04: cellular or porous - C08J 2323/06: Polyethene - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS ## 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. ## Claims ### Claim 1 A method for producing an ultra-high-molecular-weight polyethylene porous membrane, comprising: a step of molding a film using an ultra-high-molecular-weight polyethylene raw material having a viscosity average molecular weight of from 1,000,000 to 12,000,000; a step of biaxially stretching the film obtained in the above step, in X-axis and Y-axis directions in a temperature range of from a melting point of the film to 180° C.; a step of shrinking the biaxially stretched film obtained in the above step, along at least one axis of the X-axis or Y-axis; and a pore-forming step of stretching the shrunk film obtained in the above step, along at least one axis of the X-axis or Y-axis in a temperature range of from 142° C. to 170° C. ### Claim 2 (depends on 1) The method for producing an ultra-high-molecular-weight polyethylene porous membrane according to claim 1, wherein the step of shrinking is performed in a temperature range of from 120° C. to 180° C. ### Claim 3 (depends on 1) The method for producing an ultra-high-molecular-weight polyethylene porous membrane according to claim 1, further comprising a step of annealing the film at a temperature of from 80° C. to 180° C. after the step of biaxially stretching or the step of shrinking. ### Claim 4 (depends on 1) The method for producing an ultra-high-molecular-weight polyethylene porous membrane according to claim 1, comprising a step of cooling the film to a temperature that is lower than a final temperature in a previous step by from 10° C. to 160° C., before the pore-forming step but after the step of biaxially stretching or the step of shrinking. ### Claim 5 (depends on 1) The method for producing an ultra-high-molecular-weight polyethylene porous membrane according to claim 1, wherein at least one step of the step of biaxially stretching, the step of shrinking, or the pore-forming step is performed a plurality of times in any order of the steps. ### Claim 6 (depends on 1) An ultra-high-molecular-weight polyethylene porous membrane obtained by the production method according to claim 1. ### Claim 7 A method for producing an ultra-high-molecular-weight polyethylene film, comprising: a film-molding step of molding a film by performing at least two steps of a press-molding step and a roll-molding step, using an ultra-high-molecular-weight polyethylene raw material having a viscosity average molecular weight of from 1,000,000 to 12,000,000; and a step of biaxially stretching the film obtained in the above step, in X-axis and Y-axis directions in a temperature range of from a melting point of the film to 180° C. ### Claim 8 (depends on 7) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 7, wherein the film-molding step includes, in this order: a roll-molding step of roll-molding an ultra-high-molecular-weight polyethylene raw material having a viscosity average molecular weight of from 1,000,000 to 12,000,000 to mold a film; and a press-molding step of stacking a plurality of the films obtained in the roll-molding step, and then press-molding the plurality of the films. ### Claim 9 (depends on 8) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 8, wherein, in the press-molding step, the plurality of the films obtained in the roll-molding step are stacked so as to have roll-molded directions different from each other. ### Claim 10 (depends on 7) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 7, comprising, after the step of biaxially stretching, a step of shrinking the biaxially stretched film obtained in the above step, along at least one axis of the X-axis or Y-axis. ### Claim 11 (depends on 10) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 10, wherein the step of shrinking is performed in a temperature range of from 120° C. to 180° C. ### Claim 12 (depends on 7) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 7, further comprising a step of annealing the film in a temperature range of from 80° C. to 180° C. after the step of biaxially stretching. ### Claim 13 (depends on 10) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 10, wherein at least one step of the step of biaxially stretching or the step of shrinking is performed a plurality of times in any order of the steps. ### Claim 14 (depends on 10) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 10, further comprising a pore-forming step of stretching the film along at least one axis of the X-axis or the Y-axis to obtain a porous membrane, after the step of biaxially stretching or the step of shrinking. ### Claim 15 (depends on 7) An ultra-high-molecular-weight polyethylene film obtained by the production method according to claim 7, having: a film thickness of from 0.1 μm to 100 μm; an oxygen permeability coefficient, measured at room temperature, of less than or equal to 1×10−10 cm3(STP)cm/(cm2·s·cmHg); and a strength at break of greater than or equal to 30 MPa. ### Claim 16 (depends on 10) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 10, further comprising a step of annealing the film in a temperature range of from 80° C. to 180° C. after the step of biaxially stretching or the step of shrinking. ### Claim 17 (depends on 16) The method for producing an ultra-high-molecular-weight polyethylene film according to claim 16, further comprising a pore-forming step of stretching the film along at least one axis of the X-axis or the Y-axis to obtain a porous membrane, after the step of biaxially stretching, the step of shrinking, or the step of annealing. ### Claim 18 (depends on 3) The method for producing an ultra-high-molecular-weight polyethylene porous membrane according to claim 3, comprising a step of cooling the film to a temperature that is lower than a final temperature in a previous step by from 10° C. to 160° C., before the pore-forming step but after the step of biaxially stretching, the step of shrinking, or the step of annealing. ### Claim 19 (depends on 3) The method for producing an ultra-high-molecular-weight polyethylene porous membrane according to claim 3, wherein at least one step of the step of biaxially stretching, the step of shrinking, the step of annealing, or the pore-forming step is performed a plurality of times in any order of the steps. ### Claim 20 (depends on 4) An ultra-high-molecular-weight polyethylene porous membrane obtained by the production method according to claim 4.