# US 10,766,237 B2 · Polyester film, laminate, and packaging bag > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,766,237 B2 - Document ID: US10766237B2 - Status: Granted - Kind: B2 - Application number: 16/313,746 - Filed: 2017-06-20 - Published: 2019-10-17 - Granted: 2020-09-08 - Earliest claimed: 2016-06-30 - Assignees: Toyobo Co., Ltd. - Applicants: Toyobo Co., Ltd. - Inventors: Shintaro Ishimaru; Masayuki Haruta - Web page: https://patentgrep.com/patent/US10766237B2 ## CPC - B32B 27/36: comprising polyesters - B32B 3/04: characterised by {at least one} layer folded at the edge, e.g. over another layer {; characterised by at least one layer enveloping or enclosing a material} - B32B 3/263: {characterised by a layer having non-uniform thickness} - B32B 27/08: of synthetic resin - B32B 27/16: specially treated, e.g. irradiated - B32B 27/18: characterised by the use of special additives - B65D 65/40: Applications of laminates for particular packaging purposes {(B65D1/0215, B65D1/28, B65D3/22, B65D5/0281, B65D5/563, B65D9/30, B65D29/02, B65D31/02, B65D75/26, B65D77/2024, B65D81/1275, B65D81/3811, B65D81/3823, B65D81/3834, B65D81/3846, B65D81/3858, B65D81/3874, B65D81/3886, B65D81/3897 take precedence; laminates per se or laminated packages characterised by the composition or)} - B32B 2250/03: 3 layers - B32B 2250/244: All polymers belonging to those covered by group B32B27/36 - B32B 2264/0214: Particles made of materials belonging to B32B27/00 - B32B 2264/0235: Aromatic vinyl resin, e.g. styrenic (co)polymers - B32B 2264/025: Acrylic resin particles, e.g. polymethyl methacrylate or ethylene-acrylate copolymers - B32B 2264/102: Oxide or hydroxide - B32B 2264/104: Oxysalt, e.g. carbonate, sulfate, phosphate or nitrate particles - B32B 2270/00: Resin or rubber layer containing a blend of at least two different polymers - B32B 2307/30: having particular thermal properties - B32B 2307/40: having particular optical properties - B32B 2307/412: Transparent - B32B 2307/516: mono-axially - B32B 2307/518: bi-axially - B32B 2307/546: Flexural strength; Flexion stiffness - B32B 2307/702: Amorphous - B32B 2307/7248: Odour barrier - B32B 2307/732: Dimensional properties - B32B 2307/736: Shrinkable - B32B 2307/75: Printability - B32B 2439/00: Containers; Receptacles - B32B 2439/06: Bags, sacks, sachets - B32B 2439/46: Bags - B32B 2553/00: Packaging equipment or accessories not otherwise provided for - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES ## Abstract The polyester film is formed with a polyester resin whose main constituent component is ethylene terephthalate. The polyester film has two or more layers that include at least one fold holding layer, which is present on at least one of the film surfaces and has a total of at least one monomer component that can form an amorphous component of 12-30% by mol in all monomer components of the fold holding layer and a difference in amount of an amorphous component of 4-30% by mol obtained by deducting an amount of an amorphous component in a layer other than the fold holding layer from the amount of the amorphous component in the fold holding layer. The polyester film has a fold holding angle of 20-70 degrees and a heat shrinkage rate of 0-15% in the longitudinal and width directions when treated in 80° C. hot water for 10 seconds. ## Claims ### Claim 1 A polyester film which is formed with a polyester resin whose main constituent component is ethylene terephthalate as a main component, and satisfies requirements (1) to (5) below: (1) the polyester film having two or more layers that include at least one fold holding layer, and wherein the fold holding layer is present on at least one of the film surfaces; (2) the fold holding layer comprising a total of 12% by mol or more and 30% by mol or less of at least one monomer component that forms an amorphous component in all monomer components of the fold holding layer, and a difference in amount of an amorphous component being 4% by mol or more and 30% by mol or less that is obtained by deducting an amount of an amorphous component in a layer other than the fold holding layer from the amount of the amorphous component in the fold holding layer; (3) the polyester film having a fold holding angle of 20 degrees or more and 70 degrees or less; (4) the polyester film having a heat shrinkage rate of 0% or more and 15% or less both in a longitudinal direction and a width direction when treated in 80° C. hot water over 10 seconds; and (5) the layer other than the fold holding layer comprises an ethylene terephthalate unit as a main constituent component and the amorphous component. ### Claim 2 (depends on 1) The polyester film according to claim 1, which has a haze of 1% or more and 12% or less. ### Claim 3 (depends on 2) The polyester film according to claim 2, which has a thickness unevenness of 18% or less both in the longitudinal direction and the width direction. ### Claim 4 (depends on 3) The polyester film according to claim 3, which is a uniaxially stretched film or a biaxially stretched film. ### Claim 5 (depends on 4) A packaging bag including at least one of the polyester film according to claim 4. ### Claim 6 (depends on 4) A laminate comprising at least one layer of the polyester film according to claim 4. ### Claim 7 (depends on 6) A packaging bag including at least one of the laminate according to claim 6. ### Claim 8 (depends on 2) The polyester film according to claim 2, which is a uniaxially stretched film or a biaxially stretched film. ### Claim 9 (depends on 1) The polyester film according to claim 1, which has a thickness unevenness of 18% or less both in the longitudinal direction and the width direction. ### Claim 10 (depends on 9) The polyester film according to claim 9, which is a uniaxially stretched film or a biaxially stretched film. ### Claim 11 (depends on 1) The polyester film according to claim 1, which is a uniaxially stretched film or a biaxially stretched film. ### Claim 12 (depends on 1) A packaging bag including at least one of the polyester film according to claim 1. ### Claim 13 (depends on 1) A laminate comprising at least one layer of the polyester film according to claim 1. ### Claim 14 (depends on 13) A packaging bag including at least one of the laminate according to claim 13.