Heat-shrinkable polyester film

Patent metadata

Field	Value
Publication number	US-9920162-B2
Application number	US-201314424339-A
Country	US
Kind code	B2
Filing date	Aug 28, 2013
Priority date	Aug 29, 2012
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

The invention provides a heat-shrinkable polyester film with high mechanical strength in a width direction that is orthogonal to the main shrinking direction and high tensile rupture elongation in the film width direction after being subjected to an aging treatment in a high-temperature environment. The heat-shrinkable polyester film is made from a polyester resin containing ethylene terephthalate as the main component and a monomer component that can serve as an amorphous component in an amount of 0 mol % or more and less than 1 mol % relative to the total amount of polyester resin components.

First claim

The invention claimed is:

1. A heat-shrinkable film consisting of a polyester, wherein the polyester consists of (i) ethylene terephthalate as a major constituent and (ii) an amount from 0 mol % to less than 1 mol %, based on the polyester as a whole, of a monomer component capable of forming an amorphous component, and wherein the film satisfies the following requirements (1) to (4):
(1) the film has a heat shrinkage of not less than −1% and not more than 5% in a longitudinal direction when treated for 5 minutes in a hot air oven at 90° C.;
(2) the film has a heat shrinkage of not less than 15% and not more than 40% in a longitudinal direction when treated for 5 minutes in a hot air oven heated to 140° C.;
(3) the film has a heat shrinkage of not less than −5% and not more than 5% in a width direction when treated for 5 minutes in a hot air oven heated to 140° C.; and
(4) the film has a rupture elongation of not less than 25% and not more than 80% in a film width direction after being aged for 672 hours in a thermo-hygrostat set at 60° C.

2. The heat-shrinkable polyester film according to claim 1 , wherein the film has a tensile rupture strength of not less than 200 MPa and not more than 400 MPa in the width direction.

3. The heat-shrinkable polyester film according to claim 2 , wherein the film has a refractive index of not less than 1.62 and not more than 1.66 in the width direction.

4. The heat-shrinkable polyester film according to claim 3 , wherein the film has a haze of not less than 2% and not more than 12%.

5. The heat-shrinkable polyester film according to claim 4 , wherein the film has a dynamic friction coefficient of not less than 0.1 and not more than 0.7 between one surface of the film and a back surface thereof.

6. The heat-shrinkable polyester film according to claim 5 , wherein the film has a static electricity of 5 kV or less at the time when a product roll is wound off at a speed of 200 m/min after being aged for 672 hours in an environmental test chamber set at 60° C.

7. The heat-shrinkable polyester film according to claim 1 , wherein the film has a refractive index of not less than 1.62 and not more than 1.66 in the width direction.

8. The heat-shrinkable polyester film according to claim 1 , wherein the film has a haze of not less than 2% and not more than 12%.

9. The heat-shrinkable polyester film according to claim 1 , wherein the film has a dynamic friction coefficient of not less than 0.1 and not more than 0.7 between one surface of the film and a back surface thereof.

10. The heat-shrinkable polyester film according to claim 1 , wherein the film has a static electricity of 5 kV or less at the time when a product roll is wound off at a speed of 200 m/min after being aged for 672 hours in an environmental test chamber set at 60° C.

Assignees

• Toyo Boseki

Inventors

• Haruta Masayuki
• Ishimaru Shintaro
• Endo Takuro

Classifications

• C08L67/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title

• Y10T428/1331

  Single layer [continuous layer] · CPC title

• B29C61/003

  characterised by the choice of material · CPC title

• B29K2067/003

  PET, i.e. poylethylene terephthalate · CPC title

• C08L67/03

  the dicarboxylic acids and dihydroxy compounds having the carboxyl- and the hydroxy groups directly linked to aromatic rings · CPC title