US 12,227,629 B2
Heat-shrinkable film and heat-shrinkable label
Takuma Kaneko, Osaka (JP); Masahiro Watanabe, Osaka (JP); Yuichiro Kanzaka, Osaka (JP); and Shuuta Yuge, Osaka (JP)
Assigned to C.I. TAKIRON CORPORATION, Osaka (JP)
Appl. No. 17/059,151
Filed by C.I. TAKIRON CORPORATION, Osaka (JP)
PCT Filed May 29, 2019, PCT No. PCT/JP2019/021402
§ 371(c)(1), (2) Date Nov. 25, 2020,
PCT Pub. No. WO2019/230843, PCT Pub. Date Dec. 5, 2019.
Claims priority of application No. 2018-102332 (JP), filed on May 29, 2018.
Prior Publication US 2021/0214583 A1, Jul. 15, 2021
Int. Cl. C08J 7/043 (2020.01); B29C 55/14 (2006.01); B29C 61/02 (2006.01); B29K 105/02 (2006.01); B29L 31/00 (2006.01); B32B 7/028 (2019.01); B32B 27/36 (2006.01); C08G 63/12 (2006.01); C08G 63/127 (2006.01); C08G 63/137 (2006.01); C08G 63/16 (2006.01); C08G 63/183 (2006.01); C08G 63/199 (2006.01); C08J 5/18 (2006.01); C08K 3/36 (2006.01); C08L 67/02 (2006.01); C08L 67/03 (2006.01); C09J 7/25 (2018.01); C09J 7/38 (2018.01); G09F 3/00 (2006.01); G09F 3/02 (2006.01)
CPC C08J 7/043 (2020.01) [B29C 55/14 (2013.01); B29C 61/02 (2013.01); C08J 5/18 (2013.01); C09J 7/255 (2018.01); C09J 7/385 (2018.01); G09F 3/0291 (2013.01); B29K 2105/02 (2013.01); B29L 2031/744 (2013.01); B32B 7/028 (2019.01); B32B 27/36 (2013.01); C08G 63/12 (2013.01); C08G 63/127 (2013.01); C08G 63/137 (2013.01); C08G 63/16 (2013.01); C08G 63/183 (2013.01); C08G 63/199 (2013.01); C08J 2333/08 (2013.01); C08J 2367/02 (2013.01); C08K 3/36 (2013.01); C08L 67/02 (2013.01); C08L 67/03 (2013.01); C09J 2203/334 (2013.01); C09J 2301/122 (2020.08); C09J 2301/312 (2020.08); C09J 2301/41 (2020.08); C09J 2400/10 (2013.01); C09J 2433/00 (2013.01); C09J 2467/006 (2013.01); G09F 2003/023 (2013.01); G09F 2003/0251 (2013.01); G09F 2003/0273 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A heat-shrinkable film comprising:
polyester, wherein the polyester comprises a dicarboxylic acid component and a diol component, the dicarboxylic component comprising 95 mol % or more of terephthalic acid, and the diol component comprising 67 to 71 mol % of ethylene glycol and 24 to 28 mol % of cyclohexanedimethanol, and 3 to 7 mol % of diethylene glycol,
wherein the polyester is at least 95 mass % of the total composition,
a shrinkage rate in a primary shrinkage direction when the heat-shrinkable film is immersed in hot water at 70° C. for 30 seconds is 20% or less,
a shrinkage rate in the primary shrinkage direction when the heat-shrinkable film is immersed in hot water at 80° C. for 30 seconds is 45% to 65%, and
a shrinkage rate in the primary shrinkage direction when the heat-shrinkable film is immersed in hot water at 98° C. for 30 seconds is 65% or more,
the heat-shrinkable film is produced by a method comprising melt-extruding a resin material containing polyester to obtain an unstretched film, stretching the unstretched film in the longitudinal direction and then stretching the unstretched film in the width direction to obtain a stretched film, and thermally treating the stretched film,
the stretch ratio at the time of stretching the unstretched film in the longitudinal direction is 3.5 to 5 times,
the stretching temperature at the time of stretching the unstretched film in the longitudinal direction is higher than a glass transition temperature of the polyester by 5° C. to 15° C.,
the stretch ratio at the time of stretching the unstretched film in the width direction is 1 to 1.3 times,
the stretching temperature at the time of stretching the unstretched film in the width direction is higher than the glass transition temperature by −5° C. to 10° C., and
the thermal treatment temperature at the time of thermally treating the stretched film is higher than the stretching temperature at the time of stretching the unstretched film in the width direction by 0° C. to 20° C.