Polyester sealant film, laminate and package

Patent metadata

Field	Value
Publication number	US-2021101379-A1
Application number	US-201816481826-A
Country	US
Kind code	A1
Filing date	Feb 8, 2018
Priority date	Feb 15, 2017
Publication date	Apr 8, 2021
Grant date	—

Abstract

The invention provides a polyester sealant film having at least one of a heat sealing layer and a heat resistant layer, wherein each layer consists of a polyester component containing ethylene terephthalate. The polyester sealant film has (1) a heat sealing strength of the heat sealing layers of 8-20 N/15 mm; (2) a difference in reversible heat capacity (ΔCp) for the heat sealing layer of 0.5-1.1 J/g/K; (3) a ΔCp for the heat resistant layer of 0.1 to less than 0.6 J/g/K; (4) a fold holding angle of 20-60 degrees; (5) a smaller curvature radius of 50-300 mm in a longitudinal or widthwise direction; and (6) a heat shrinkage ratio of −5% to 5% in both longitudinal and widthwise directions. The invention also provides a laminate comprising at least one layer of the polyester sealant and a packaging bag comprising the laminate.

First claim

1 . A polyester sealant film having at least one of a heat sealing layer and a heat resistant layer, wherein each layer consists of a polyester component which comprises ethylene terephthalate as a main component,
wherein the polyester sealant film satisfies following requirements (1) to (6): (1) a heat sealing strength of the heat sealing layers being heat-sealed to another heat sealing layer at 140° C. and 0.2 MPa for 2 seconds is 8 N/15 mm or more and 20 N/15 mm or less; (2) the heat sealing layer has a difference in reversible heat capacity (□Cp) between a glass transition temperature and 140° C. of 0.5 J/g/K or more and 1.1 J/g/K or less when measured with a temperature modulated DSC; (3) the heat resistant layer has a ΔCp of 0.1 J/g/K or more and less than 0.6 J/g/K when measured with the temperature modulated DSC; (4) the film has a fold holding angle of 20 degrees or more and 60 degrees or less; (5) the film has a smaller curvature radius of 50 mm or more and 300 mm or less in a longitudinal direction or a widthwise direction; and (6) the film has a heat shrinkage ratio of -5% or more and 5% or less in both a longitudinal direction and a widthwise direction after immersed in hot water of 80° C. for 10 seconds.

2 . The polyester sealant film according to claim 1 ,
wherein the polyester component constituting the heat sealing layer comprises a diol monomer component other than ethylene glycol as a monomer component, and the polyester component constituting the heat resistant layer comprises a diol monomer component other than ethylene glycol as a monomer component; and wherein the diol monomer component in the heat sealing layer and the heat resistant layer is at least one of neopentyl glycol, 1,4-cyclohexane dimethanol, 1,4-butanediol or diethylene glycol.

3 . The polyester sealant film according to claim 1 ,
wherein the polyester component constituting the heat sealing layer comprises a diol monomer component other than ethylene glycol as a monomer component, and the polyester component constituting the heat resistant layer comprises a diol monomer component other than ethylene glycol as a monomer component; and wherein a content of the diol monomer component relative to the monomer component in the heat sealing layer or the heat resistant layer satisfies following requirements (1) to (3): (1) the content of the diol monomer component in the heat sealing layer is 30% or more by mol and 50% or less by mol; (2) the content of the diol monomer component in the heat resistant layer is 9% or more by mol and 20% or less by mol; and (3) a difference of the content of the diol monomer component between the heat sealing layer and the heat resistant layer is 20% or more by mol and 35% or less by mol.

4 . A laminate comprising at least one layer of the polyester sealant film according to claim 1 .

5 . A packaging bag comprising the polyester sealant film according to claim 1 as at least a part thereof.

6 . A packaging bag comprising the laminate according to claim 4 as at least a part thereof.

7 . The polyester sealant film according to claim 2 ,
wherein the polyester component constituting the heat sealing layer comprises a diol monomer component other than ethylene glycol as a monomer component, and the polyester component constituting the heat resistant layer comprises a diol monomer component other than ethylene glycol as a monomer component; and wherein a content of the diol monomer component relative to the monomer component in the heat sealing layer or the heat resistant layer satisfies following requirements (1) to (3): (1) the content of the diol monomer component in the heat sealing layer is 30% or more by mol and 50% or less by mol; (2) the content of the diol monomer component in the heat resistant layer is 9% or more by mol and 20% or less by mol; and (3) a difference of the content of the diol monomer component between the heat sealing layer and the heat resistant layer is 20% or more by mol and 35% or less by mol.

8 . A laminate comprising at least one layer of the polyester sealant film according to claim 7 .

9 . A packaging bag comprising the polyester sealant film according to claim 7 as at least a part thereof.

10 . A packaging bag comprising the laminate according to claim 8 as at least a part thereof.

Assignees

• Toyo Boseki

Inventors

• Ishimaru Shintaro
• Haruta Masayuki

Classifications

• B32B2307/732

  Dimensional properties · CPC title

• B32B2307/546

  Flexural strength; Flexion stiffness · CPC title

• B32B2307/408

  Matt, dull surface · CPC title

• B32B2307/306

  Resistant to heat · CPC title

• B32B2307/308

  Heat stability · CPC title