	US 12,286,516 B2
	Film roll of heat-shrinkable polyester
Masafumi Inoue, Tsuruga (JP); and Masayuki Haruta, Tsuruga (JP)
Assigned to TOYOBO CO., LTD., Osaka (JP)
Appl. No. 17/765,525
Filed by TOYOBO CO., LTD., Osaka (JP)
PCT Filed Sep. 23, 2020, PCT No. PCT/JP2020/035696 § 371(c)(1), (2) Date Mar. 31, 2022, PCT Pub. No. WO2021/065596, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 2019-182017 (JP), filed on Oct. 2, 2019.
Prior Publication US 2022/0267541 A1, Aug. 25, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. B29C 55/06 (2006.01); B29C 55/14 (2006.01); B29C 61/02 (2006.01); B65H 75/10 (2006.01); C08J 5/18 (2006.01)

CPC C08J 5/18 (2013.01) [B29C 55/06 (2013.01); B29C 55/14 (2013.01); B29C 61/02 (2013.01); B65H 75/10 (2013.01); C08J 2367/00 (2013.01)]

8 Claims

1. A film roll of heat-shrinkable polyester film obtained by winding around a paper pipe with heat-shrinkable polyester film having a longitudinal direction as a main shrinkage direction,

wherein the polyester film has a shrinkage of 40% or more in the main shrinkage direction after a treatment in hot water of 90° C. for 10 seconds,

wherein the polyester film is obtained from a polyester comprising

(a) 50 mol % or more of ethylene terephthalate based on 100 mol % total constituent components of the polyester,

(b) 0-3 mol % of one or more aliphatic dicarboxylic acids based on 100 mol % total polycarboxylic acid content, and

(c) 14 mol % or more of one or more monomers which can form an amorphous component based on 100 mol % total polyhydric alcohol content or 100 mol % total polycarboxylic acid content,

wherein the monomers which can form an amorphous component are selected from the group consisting of 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, and hexanediol,

wherein the polyester has a glass transition temperature (Tg) of 60° C. to 80° C., and

wherein the film roll satisfies the following requirements (1) to (7):

(1) a winding length of the film is 1000-30000 m;

(2) a width of the film is 50-1500 mm;

(3) a thickness of the film is 5-30 μm;

(4) a thickness unevenness of the film is 20% or less over a whole width direction of the film on a surface of the film roll;

(5) an internal diameter of the paper pipe is 3 inch, a gap difference of the paper pipe in a width direction of the paper roll is 0.5 mm or less after a removal of the film from the film roll, and a flattening pressure strength of the paper pipe is 1700 N/100 mm or more after the removal of the film;

(6) an average winding hardness of the film in a width direction of the film is 500-850 on the surface of the film roll; and

(7) a natural shrinkage of the film in a longitudinal direction of the film is 2.0% or less after aging the film in an atmosphere of 40° C. and 85% relative humidity for 28 days.