# US 11,999,849 B2 · Biaxially oriented polyamide film and polyamide film mill roll > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,999,849 B2 - Document ID: US11999849B2 - Status: Granted - Kind: B2 - Application number: 17/281,638 - Filed: 2019-09-27 - Published: 2021-12-23 - Granted: 2024-06-04 - Earliest claimed: 2018-10-05 - Assignees: Toyobo Co., Ltd. - Applicants: Toyobo Co., Ltd. - Inventors: Takuro Endo; Kosuke Hama - Web page: https://patentgrep.com/patent/US11999849B2 ## CPC - C08L 77/02: Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08L77/10 takes precedence) - C08L 77/06: Polyamides derived from polyamines and polycarboxylic acids (C08L77/10 takes precedence) - B29C 55/12: biaxial - B29C 55/14: successively - C08G 18/0823: {containing carboxylate salt groups or groups forming them} - C08G 18/10: Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step - C08G 18/4222: {derived from aromatic polyhydroxy compounds and polycarboxylic acids} - C08G 18/4252: {derived from polyols containing polyether groups and polycarboxylic acids} - C08J 5/18: Manufacture of films or sheets - C09D 175/06: from polyesters - C09J 7/25: based on macromolecular compounds obtained otherwise than by reactions involving only carbon-to-carbon unsaturated bonds - B29K 2077/00: Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material - B29K 2995/0053: bi-axially - C08J 2377/00: Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers - C08L 2203/16: used for films - C09J 2477/006: in the substrate - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - 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) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - 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) - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - 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 To provide a biaxially oriented polyamide film, even as a product that is close to an end of a mill roll, having favorable mechanical characteristics, thermal characteristics, and few S-shape curling due to moisture absorption after being made into a bag. A biaxially oriented polyamide film formed of a polyamide resin containing not lower than 60% by mass of polyamide 6, wherein a molecular orientation angle of the film is not smaller than 20°, a strain at moisture absorption of the film is not higher than 1.3%, an impact strength of the film is not lower than 0.8 J/15 μm, and a heat shrinkage rate, after heating for ten minutes at 160° C., of the film is 0.6 to 3.0% in both an MD direction and a TD direction. ## Claims ### Claim 1 A biaxially oriented polyamide film formed of a polyamide resin containing not lower than 60% by mass of polyamide 6, wherein a molecular orientation angle of the film is not smaller than 20°, a strain at moisture absorption of the film is not higher than 1.3%, an impact strength of the film is not lower than 0.8 J/15 μm, and a heat shrinkage rate, after heating for ten minutes at 160° C., of the film is 0.6 to 3.0% in both an MD direction and a TD direction. ### Claim 2 (depends on 1) The biaxially oriented polyamide film according to claim 1, wherein the biaxially oriented polyamide film is formed of a polyamide resin containing not lower than 90% by mass of polyamide 6. ### Claim 3 (depends on 2) The biaxially oriented polyamide film according to claim 2, wherein a strain at thermal shrinkage, after heating for ten minutes at 160° C., of the film is not higher than 2.0%. ### Claim 4 (depends on 3) The biaxially oriented polyamide film according to claim 3, wherein the biaxially oriented polyamide film comprises, on at least one surface thereof, an easily adhesive layer having a coating amount of 0.01 to 3 g/m2 in terms of solid content and formed of any of a polyester resin, a polyurethane resin, and/or a polyacrylic resin. ### Claim 5 (depends on 1) The biaxially oriented polyamide film according to claim 1, wherein a strain at thermal shrinkage, after heating for ten minutes at 160° C., of the film is not higher than 2.0%. ### Claim 6 (depends on 1) The biaxially oriented polyamide film according to claim 1, wherein the biaxially oriented polyamide film comprises, on at least one surface thereof, an easily adhesive layer having a coating amount of 0.01 to 3 g/m2 in terms of solid content and formed of any of a polyester resin, a polyurethane resin, and/or a polyacrylic resin. ### Claim 7 A polyamide film mill roll of a biaxially oriented polyamide film formed of a polyamide resin containing not lower than 60% by mass of polyamide 6, wherein an impact strength at each of positions of the film that are inward by 300 mm from a right end and a left end in a transverse direction of the film mill roll is not lower than 0.8 J/15 μm, a strain at moisture absorption at each position is not higher than 1.3%, and a heat shrinkage rate, after heating for ten minutes at 160° C., at each position is 0.6 to 3.0% in both an MD direction and a TD direction. ### Claim 8 (depends on 7) The polyamide film mill roll according to claim 7, wherein the biaxially oriented polyamide film comprises, on at least one surface thereof, an easily adhesive layer having a coating amount of 0.01 to 3 g/m2 in terms of solid content and formed of any of a polyester resin, a polyurethane resin, and/or a polyacrylic resin. ### Claim 9 (depends on 8) The polyamide film mill roll according to claim 8, wherein a strain at thermal shrinkage, after heating for ten minutes at 160° C., at each of the positions of the film that are inward by 300 mm from the right end and the left end in the transverse direction of the film mill roll is not higher than 2.0%. ### Claim 10 (depends on 7) The polyamide film mill roll according to claim 7, wherein a strain at thermal shrinkage, after heating for ten minutes at 160° C., at each of the positions of the film that are inward by 300 mm from the right end and the left end in the transverse direction of the film mill roll is not higher than 2.0%.