Biaxially extended polyester film

• US 5,897,959 A
• Filed: 11/20/1996
• Issued: 04/27/1999
• Est. Priority Date: 11/24/1995
• Status: Expired due to Term

• Current Assignee: SKC Incorporated (SKC Company Limited)
• Original Assignee: SKC Incorporated (SKC Company Limited)
• Inventors: Cho, Byoung-Ho, Kim, Sang-Il
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US08/752,509
• Time in Patent Office: 888 Days
• Field of Search: 428/480, 428/910, 428/458, 524/151, 524/153, 524/127, 524/128, 524/147, 524/287, 524/342
• US Class Current: 428/480
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 2307/308 Heat stability
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]

Abstract

A biaxially extended polyester film which comprises a polyester resin having ethylene A biaxially oriented polyester film comprises a polyester resin having ethylene terephthalate and ethylene isophthalate repeating units in a weight ratio of 90:10 to 75:25; 0.02 to 0.06 weight % of an organic phosphite or phosphate ester; and 0.01 to 0.05 weight % of a hindered phenol compound, wherein the film possesses good thermal stability, processability, and thermal adhesive strength to a metal surface and is useful in forming the inner laminate layer of a metal container.

Claims

1. A biaxially extended polyester film which comprises a polyester resin having ethylene terephthalate and ethylene isophthalate repeating units in a weight ratio of 90:

10 to 75;

25, and an organic phosphite or phosphate ester in an amount ranging from 0.02 to 0.06 wt % and a hindered phenol compound in an amount ranging from 0.01 to 0.05 wt % based on the weight of the polyester resin.

2. The polyester film of claim 1 wherein the polyester resin has an intrinsic viscosity of 0.55 to 0.75 dl/g.

3. The polyester film of claim 1 wherein the organic phosphite or phosphate ester is selected from the group consisting of triphenyl phosphate, tricresyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trixyrenyl phosphate, xyrenyl diphenyl phosphate, cresyl diphenyl phosphate, di-stearylpentaerythritol diphosphite, bis 2,4-di-t-butylphenylpentaerythritol diphosphite, tris 2,4-di-t-butylphenylpentaerythritol diphosphite, and a mixture thereof.

4. The polyester film of claim 1 wherein the hindered phenol compound is selected from the group consisting of tetrakis 3,5-di-t-butyl-hydroxyphenylpropanoxymethylmethane, octadecyl 3,5-di-t-butyl-hydroxyphenylpropanoate, 2-hydroxy-4-n-octabenzophenone, 2,4-di-t-butylphenyl 3,5-di-t-butyl-4-hydroxybenzoate, and a mixture thereof.