# US 5,346,752 A · Heat-resistant moistureproof film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,752 A - Document ID: US5346752A - Status: Granted - Kind: A - Application number: 07/859,702 - Filed: 1992-07-29 - Granted: 1994-09-13 - Earliest claimed: 1990-10-17 - Assignees: Mitsubishi Kasei Corporation - Inventors: Tsutomu Sawada; Shinichi Ohashi; Shigenobu Yoshida - Web page: https://patentgrep.com/patent/US5346752A ## CPC - B32B 27/306: {comprising vinyl acetate or vinyl alcohol (co)polymers} - B32B 27/08: of synthetic resin - B32B 27/286: {comprising polysulphones; polysulfides} - H05B 33/04: Sealing arrangements {, e.g. against humidity} - B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer - B32B 2255/20: Inorganic coating - B32B 2307/306: Resistant to heat - B32B 2307/31: Heat sealable - B32B 2307/412: Transparent - B32B 2307/7246: Water vapor barrier - B32B 2329/04: Polyvinylalcohol - Y10S 428/91: Product with molecular orientation - Y10S 428/913: Material designed to be responsive to temperature, light, moisture - Y10S 428/917: Electroluminescent - Y10S 428/918: Material abnormally transparent - Y10T 428/24975: No layer or component greater than 5 mils thick - Y10T 428/2826: Synthetic resin or polymer - Y10T 428/31913: Monoolefin polymer - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A heat-resistant moistureproof film having a first layer (A), a second layer (B) bonded to one side of the first layer, and a third layer (C) bonded to the other side of the first layer. The first layer (A) is a single or a laminate of a transparent laminated film having a base film composed of PVA having a saponification degree of not less than 99 mol % and a transparent silicon oxide thin film (SO thin film) 2 formed on at least one side thereof. The second layer (B) is a single or a laminate of a transparent plastic film other than a PVA film, having at least one layer of the plastic film with a transparent SO thin film 4 having a thickness of 100 to 5000 .ANG. formed on at least one side thereof, and at least one layer of a transparent heat-resistant film having the sum of the absolute values of the percentages of heat-shrinkage in the machine direction and transverse direction when heated at 150.degree. C. for 30 minutes, of not more than 1% and a light transmittance of not less than 85% by ASTM D-1003. The the third layer (C) is a heat-sealable resin layer. ## Claims ### Claim 1 A heat-resistant moistureproof film comprising: a first layer (A), the first layer (A) being a transparent laminated film comprising: a base film composed of a polyvinyl alcohol having a saponification degree of not less than 99 mol%; and, a first transparent silicon oxide thin film formed on at least one side of the base film; a second layer (B) bonded to one side of the first layer (A), the second layer (B) comprising: at least one layer of a transparent plastic film other than a polyvinyl alcohol film; and, a second transparent silicon oxide thin film of 100 to 5000 .ANG. in thickness formed on at least one side of the transparent plastic film; and, at least one transparent plastic film being a heat-resistant film having a sum of the absolute values of percentages of heatshrinkage in a machine direction and a transverse direction when heated at 150.degree. for 30 minutes, of not more than 1% and a light transmittance of not less than 85% by ASTM D-1003; and, a third layer (C) bonded to an opposing side of the first layer (A), the third layer (C) being a heat-sealable resin layer. ### Claim 2 (depends on 1) A heat-resistant moistureproof film according to claim 1, wherein said transparent heat-resistant film has a thickness of 10 to 100 .mu.m. ### Claim 3 (depends on 1) A heat-resistant moistureproof film according to claims 1, wherein said transparent heat-resistant film is composed of a polyether sulfone having a repeating unit represented by the following chemical formula: ##STR6## ### Claim 4 (depends on 1) A heat-resistant moistureproof film according to claims 1, wherein said first and second silicon oxide thin films are formed by one of the methods selected from the group consisting of vacuum deposition method, sputtering method and ion plating method. ### Claim 5 (depends on 1) A heat-resistant moistureproof film according to claims 1, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said second layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 6 (depends on 2) A heat-resistant moistureproof film according to claim 2, wherein said transparent heat-resistant film is composed of a polyether sulfone having a repeating unit represented by the following chemical formula: ##STR7## ### Claim 7 (depends on 2) A heat-resistant moistureproof film according to claim 2, wherein said first and second silicone oxide thin films are formed by one of the methods selected from the group consisting of vacuum deposition method, sputtering method and ion plating method. ### Claim 8 (depends on 3) A heat-resistant moistureproof film according to claim 3, wherein said first and second silicone oxide thin films are formed by one of the methods selected from the group consisting of vacuum deposition method, sputtering method and ion plating method. ### Claim 9 (depends on 6) A heat-resistant moistureproof film according to claim 6, wherein said first and second silicone oxide thin films are formed by one of the methods selected from the group consisting of vacuum deposition method, sputtering method and ion plating method. ### Claim 10 (depends on 2) A heat-resistant moistureproof film according to claim 2, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 11 (depends on 3) A heat-resistant moistureproof film according to claim 3, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 12 (depends on 4) A heat-resistant moistureproof film according to claim 4, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 13 (depends on 6) A heat-resistant moistureproof film according to claim 6, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 14 (depends on 7) A heat-resistant moistureproof film according to claim 7, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 15 (depends on 8) A heat-resistant moistureproof film according to claim 8, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m. ### Claim 16 (depends on 9) A heat-resistant moistureproof film according to claim 9, wherein said base film and said first silicon oxide thin film of said first layer (A) have thicknesses of 5 to 400 .mu.m and 100 to 5000 .ANG., respectively, and the total thickness of said layer (B) and said third layer (C) is 50 to 1000 .mu.m.