Polyester resin for heat-shrinkable film, heat-shrinkable film, heat-shrinkable label, and packaged product

Patent metadata

Field	Value
Publication number	US-12134679-B2
Application number	US-201917276120-A
Country	US
Kind code	B2
Filing date	Sep 25, 2019
Priority date	Oct 16, 2018
Publication date	Nov 5, 2024
Grant date	Nov 5, 2024

Abstract

The invention provides 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 7 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. The polyester resin has (i) an intrinsic viscosity (IV) of not less than 0.65 and less than 0.70 dl/g, (ii) a carboxyl end group concentration (AV) of 8-25 eq/t, (iii) a color b value of 1.0-8.0 in an L*a*b* color system, and (iv) aluminum and phosphorus atoms, wherein the aluminum atoms are present in an amount of 15-40 ppm, and wherein the molar ratio of the phosphorus atoms to the aluminum atoms is 1.8-2.6.

First claim

The invention claimed is:

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.

2. A heat-shrinkable film comprising the polyester resin for heat-shrinkable film of claim 1 .

3. A heat-shrinkable label comprising the heat-shrinkable film of claim 2 .

4. A packaged product which has been formed by coating the heat-shrinkable label of claim 3 at least on a part of an outer periphery of a target to be packaged followed by a heat-shrinking treatment.

Assignees

• Toyo Boseki

Inventors

• Nakagawa Satoru
• Uotani Kosuke
• Ohashi Hideto
• Haruta Masayuki
• Ishimaru Shintaro

Classifications

• G09F3/04

  to be fastened or secured by the material of the label itself, e.g. by thermo-adhesion (by a separate adhesive layer G09F3/10) · CPC title

• G09F3/0291

  Labels or tickets undergoing a change under particular conditions, e.g. heat, radiation, passage of time · CPC title

• C08J2367/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title

• B29L2031/744

  Labels, badges, e.g. marker sleeves · CPC title