# US 11,299,595 B2 · Heat-shrinkable polyester film and package > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,299,595 B2 - Document ID: US11299595B2 - Status: Granted - Kind: B2 - Application number: 15/752,339 - Filed: 2016-08-04 - Published: 2020-07-02 - Granted: 2022-04-12 - Earliest claimed: 2015-08-19 - Assignees: Toyobo Co., Ltd. - Applicants: Toyobo Co., Ltd. - Inventors: Masafumi Inoue; Masayuki Haruta - Web page: https://patentgrep.com/patent/US11299595B2 ## CPC - B29C 61/06: Making preforms having internal stresses, e.g. plastic memory - C08J 5/18: Manufacture of films or sheets - B29C 48/0018: {combined with shaping by orienting, stretching or shrinking, e.g. film blowing (B29C48/0017 takes precedence)} - B29C 48/022: {characterised by the choice of material} - B29C 48/08: flexible, e.g. films - B29C 48/914: {Cooling drums} - C08G 63/183: Terephthalic acids - B29K 2067/00: Use of polyesters {or derivatives thereof}, as moulding material - B29L 2007/008: {Wide strips, e.g. films, webs} - C08J 2367/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) - C08J 2467/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08J2467/06 takes precedence) - 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) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - 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 - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract Provided is a heat-shrinkable polyester film which has heat shrinkage properties in a main shrinkage direction in the longitudinal direction, a small variation in shrinkage in the width direction, and less likely generated wrinkles and strains at the time of shrinkage finishing. The polyester film is prepared from a polyester raw material resin comprising 50 mol % or more of an ethylene terephthalate unit in 100 mol % of constituent units of a polyester, diol components selected from aliphatic, alicyclic, and aromatic diols, and an amorphous monomer component that is 2% or more in 100 mol % of either a polyhydric alcohol component or a polybasic carboxylic acid component in the whole polyester resin, wherein the polyester does not contain polybasic carboxylic acids of tribasic or more, and the polyester film is obtained by uniaxial drawing in the longitudinal direction. ## Claims ### Claim 1 A heat-shrinkable polyester film which satisfies the following requirements (1) to (4): (1) a hot-water shrinkage of 50% or more in a main shrinkage direction of the film when treated for 10 seconds in hot water of 98° C.; (2) when samples are taken at every 100 mm in a width direction of the film, and hot-water shrinkages in a direction orthogonal to the main shrinkage direction of the film are determined for all the samples when treated for 10 seconds in hot water of 98° C., a variation of the hot-water shrinkages is 5% or less; (3) an absolute value of a molecular orientation angle is 15 degrees or less; and (4) a refractive index difference represented by the following equation is 0.06 or more: Refractive index difference=(Refractive index in the main shrinkage direction)−(Refractive index in a direction orthogonal to the main shrinkage direction), wherein the heat-shrinkage polyester film is prepared from a polyester raw material resin comprising (A) 50-90 mol % of an ethylene terephthalate unit in 100 mol % of constituent units of a polyester, (B) diol components constituting the polyester include at least one selected from an aliphatic diol, an alicyclic diol, and an aromatic diol, and (C) 2-50 mol % of an amorphous monomer component in 100 mol % of a polyhydric alcohol component or in 100 mol % of a polybasic carboxylic acid component in the whole polyester resin, wherein the amorphous monomer component is selected from neopentyl glycol, 1,4-cyclohexanedimethanol, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-isopropyl-1,3-propanediol, 2,2-di-n-butyl-1,3-propanediol, hexanediol, and combinations thereof, and wherein the polyester raw material resin does not contain polybasic carboxylic acids of tribasic or more, wherein the polyester film is obtained by uniaxial drawing 2.5 times or more and 7 times or less in the longitudinal direction, wherein the polyester film has a main shrinkage direction in a longitudinal direction of the film, and wherein a cumulative drawing distance of a drawing distance at a first stage and a drawing distance at a second stage in the preparation of the polyester film is 200 mm or less. ### Claim 2 (depends on 1) The heat-shrinkable polyester film according to claim 1, wherein the amorphous monomer component is at least one of neopentyl glycol, cyclohexanedimethanol and isophthalic acid. ### Claim 3 (depends on 1) A package comprising a label obtained from the heat-shrinkable polyester film according to claim 1 on at least a part of an outer periphery of an object to be packaged. ### Claim 4 (depends on 2) A package comprising a label obtained from the heat-shrinkable polyester film according to claim 2 on at least a part of an outer periphery of an object to be packaged.