US 12,134,679 B2
Polyester resin for heat-shrinkable film, heat-shrinkable film, heat-shrinkable label, and packaged product
Satoru Nakagawa, Tsuruga (JP); Kosuke Uotani, Tsuruga (JP); Hideto Ohashi, Tsuruga (JP); Masayuki Haruta, Tsuruga (JP); and Shintaro Ishimaru, Tsuruga (JP)
Assigned to TOYOBO CO., LTD., Osaka (JP)
Appl. No. 17/276,120
Filed by TOYOBO CO., LTD., Osaka (JP)
PCT Filed Sep. 25, 2019, PCT No. PCT/JP2019/037548
§ 371(c)(1), (2) Date Mar. 12, 2021,
PCT Pub. No. WO2020/080051, PCT Pub. Date Apr. 23, 2020.
Claims priority of application No. 2018-194894 (JP), filed on Oct. 16, 2018.
Prior Publication US 2022/0049049 A1, Feb. 17, 2022
Int. Cl. C08G 63/197 (2006.01); B29C 61/02 (2006.01); C08J 5/18 (2006.01); G09F 3/00 (2006.01); G09F 3/04 (2006.01); B29K 67/00 (2006.01); B29K 105/00 (2006.01); B29L 31/00 (2006.01)
CPC C08G 63/197 (2013.01) [C08J 5/18 (2013.01); G09F 3/0291 (2013.01); G09F 3/04 (2013.01); B29C 61/02 (2013.01); B29K 2067/003 (2013.01); B29K 2105/0085 (2013.01); B29L 2031/744 (2013.01); C08J 2367/02 (2013.01)] 4 Claims
 
1. A polyester resin for heat-shrinkable film which contains terephthalic acid as a main component of a dicarboxylic acid component, contains ethylene glycol as a main component of a diol component, and contains from 18 to 32% by mole of neopentyl glycol and from 8 to 15% by mole of diethylene glycol when a total amount of the whole diol component in total polyester resin components is taken as 100% by mole, characterized in that the polyester resin satisfies the following requirements (i) to (iv):
(i) the polyester resin has an intrinsic viscosity (IV) of not less than 0.65 and less than 0.70 dL/g;
(ii) the polyester resin has a carboxyl end group concentration (AV) of from 8 to 25 eq/t;
(iii) the polyester resin has a color b value of from 1.0 to 8.0 in an L*a*b* color system; and
(iv) the polyester resin contains aluminum atom and phosphorus atom, wherein an amount of the aluminum atom in the polyester resin is 15 to 40 ppm and wherein a molar ratio of the phosphorus atom to the aluminum atom in the polyester resin is 1.8 to 2.6.