Gas barrier laminated film and a process for producing same

• US 20040191552A1
• Filed: 03/29/2004
• Published: 09/30/2004
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: Tohcello Co., Ltd.
• Original Assignee: Tohcello Co., Ltd.
• Inventors: Nakamura, Osamu, Toda, Kinichi
• Granted Patent: US 7,419,726 B2
• Time in Patent Office: Days
• US Class Current: 428/515
• CPC Class Codes: B32B 2305/72 Cured, e.g. vulcanised, cross-linked
• CPC Class Codes: B32B 2307/31 Heat sealable
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/7242 Non-permeable
• CPC Class Codes: B32B 2398/20 Thermoplastics
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/306 comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08J 2429/00 Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical; Hydrolysed polymers of esters of unsaturated alcohols with saturated carboxylic acids; Derivatives of such polymer
• CPC Class Codes: C08J 2433/00 Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/048 Forming gas barrier coatings
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10T 428/31667 Next to addition polymer from unsaturated monomers, or aldehyde or ketone condensation product
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

Provided is a gas barrier laminated film having no fear of deterioration in transparency and excellent in transparency and gas barrier property at a high humidity as well as a process for producing same. The present invention is featured by a gas barrier laminated film wherein a gas barrier layer (B) has been formed on at least one surface of a film substrate (A), the gas barrier layer (B) being comprised of a composition (b3) of an ethylene-vinyl alcohol copolymer (b1) having an ethylene content of 1˜19 mol % and (meth)acrylic acid polymer (b2). In case the film substrate is coated on at least one surface thereof with a vapor deposition layer of an inorganic oxide or the OPP film is coated on at least one surface thereof with the layer of the modified propylene polymer, the gas barrier laminated film is obtained which is more enhanced in adhesion power to the film substrate.

Claims

1. A gas barrier laminated film wherein a gas barrier layer (B) has been formed on at least one surface of a film substrate (A), the gas barrier layer (B) being comprised of a composition (b3) of an ethylene-vinyl alcohol copolymer (b1) having an ethylene content of 1˜

19 mol % and (meth)acrylic acid polymer (b2).

2. A gas barrier laminated film according to claim 1, wherein an inorganic oxide vapor deposition layer (a1) having been formed on the surface of the film substrate (A), and the gas barrier layer (B) is formed on the film substrate (A) through the vapor deposition layer (a1).

3. A gas barrier laminated film according to claim 1 or 2, wherein the film substrate (A) is a biaxially stretched film.

4. A gas barrier laminated film according to claim 3, wherein the film substrate (A) is a biaxially stretched polyester film.

5. A gas barrier laminated film according to claim 3, wherein the biaxially stretched film is a biaxially stretched polypropylene film.

6. A gas barrier laminated film according to claim 1, wherein the composition (b3) is 95˜

10 weight % of the ethylene-vinyl alcohol copolymer (b1) and 5˜

90 weight % of (meth)acrylic acid polymer (b2).

7. A gas barrier laminated film according to claim 1 or 2, wherein the composition (b3) has been crosslinked.

8. A gas barrier laminated film according to claim 1 or 2, wherein the (meth)acrylic acid polymer (b2) has been neutralized partially.

9. A gas barrier laminated film according to claim 8, wherein 3˜

15% of the (meth)acrylic acid polymer (b2) has been neutralized partially.

10. A gas barrier laminated film according to claim 5, wherein a layer of a modified propylene polymer (a2) has been formed on the biaxially stretched polypropylene film and the gas barrier layer (B) is formed on the film (A) through the layer of the modified propylene polymer layer (a2).

11. A gas barrier laminated film according to claim 9, wherein the modified propylene polymer (a2) has been graft-modified with an unsaturated carboxylic acid or a derivative thereof.

12. A process for producing a gas barrier laminated film, which comprises coextruding polypropylene and the modified propylene polymer (a2) to form a laminated sheet, coating the composition (b3) of the ethylene-vinyl alcohol copolymer (b1) having an ethylene content of 1˜

19 mol % and the (meth)acrylic acid polymer (b2) on the laminated sheet at the side of the layer of the modified propylene polymer (a2), and biaxially stretching the resultant laminated film.

14. A process for producing a gas barrier laminated film according to claim 12 or 13, wherein the modified propylene polymer (a2) has been graft-modified with an unsaturated carboxylic acid or a derivative thereof.

15. A process for producing a gas barrier laminated film according to claim 12 or 13, wherein 3˜

15% of the (meth)acrylic acid polymer (b2) has been neutralized partially.

13. A process for producing a gas barrier laminated film, which comprises coextruding polypropylene and the modified propylene polymer (a2) to form a laminated sheet, stretching the laminated sheet in longitudinal direction, coating the composition (b3) of the ethylene-vinyl alcohol copolymer (b1) having an ethylene content of 1˜

19 mol % and the (meth)acrylic acid polymer (b2) on the laminated sheet at the side of the layer of the modified propylene polymer (a2), and stretching the resultant laminated film in lateral direction.