Gas barrier resin film

• US 5,939,205 A
• Filed: 04/15/1997
• Issued: 08/17/1999
• Est. Priority Date: 04/16/1996
• Status: Expired due to Term

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Mitamura, Hideyuki, Yamada, Yozo, Komeda, Shigeru, Fujita, Shinji, Iseki, Kiyoshi, Yokoyama, Seiichiro, Morishige, Chikao, Osame, Satoshi
• Primary Examiner(s): KILIMAN, LESZEK B
• Application Number:
  US08/839,690
• Time in Patent Office: 854 Days
• Field of Search: 428/35.2, 428/36.6, 428/474.4, 428/475.8, 428/476.3, 428/477.7, 428/36.7, 264/235.8, 264/346
• US Class Current: 428/474.4
• CPC Class Codes: B32B 2307/7242 Non-permeable
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08J 2379/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C08J 2423/06 Polyethene
• CPC Class Codes: C08J 7/0423 with at least one layer of inorganic material and at least one layer of a composition containing a polymer binder
• 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: Y10T 428/1334 Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/1379 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1383 Vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit is sandwiched between layers [continuous layer]
• CPC Class Codes: Y10T 428/31725 Of polyamide
• CPC Class Codes: Y10T 428/31743 Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/3175 Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/31765 Inorganic-containing or next to inorganic-containing

Abstract

A gas barrier film comprising a polyamide film and an inorganic deposited layer laminated thereon, wherein the maximum shrinkage percentage after boiling treatment at 95° C. for 30 minutes is not more than 3.5%. The gas barrier film of the present invention has excellent gas barrier property and water vapor-proof property even after boiling or retort treatment. Hence, the film of the present invention can serve well as a wrapping material for a wide range of objects that require high gas barrier property, such as food, medical products, industrial materials and the like, and has great industrial value.

Claims

1. A gas barrier film comprising an inorganic vapor deposited layer and a polyamide film having a 0.01-1 μ

m thick anchor coat layer formed on at least one side thereof, said deposited layer being directly laminated on the anchor coat layer, wherein the gas barrier film has a maximum shrinkage percentage after boiling treatment at 95°

C. for 30 minutes of not more than 3.5%.

2. The film of claim 1, wherein the polyamide film has the maximum shrinkage stress at 170°

C. of not more than 900 gf/mm².

3. The film of claim 1, wherein the polyamide film has the maximum shrinkage percentage after heat treatment at 170°

C. for 10 minutes of not more than 3.5%.

4. The film of claim 3, wherein the polyamide film is obtained by first drawing an unoriented polyamide film 2.5-4.0 times in the machine direction at a temperature of not less than (Tg+10)°

C. and not more than (Tc+20)°

C., 1.1-2.9 times in the transverse direction at not less than (Tc+20)°

C. and not more than (Tc+70)°

C., and then in the transverse direction at not less than (Tc+70)°

C. and not more than (Tm-30)°

C., so that the total transverse draw ratio becomes 3.0-4.5, and then applying 0-10% relaxing heat treatment in the transverse direction using a tenter at not less than (Tm-30)°

C. and not more than (Tm-10)°

C.

5. The film of claim 1, wherein an adhesion strength between the polyamide film and the inorganic deposited layer after boiling treatment at 95°

C. for 30 minutes as determined in the air is not less than 100 g/15 mm.

6. The film of claim 1, wherein an adhesion strength between the polyamide film and the inorganic deposited layer after boiling treatment at 95°

C. for 30 minutes as determined in water is not less than 50 g/15 mm.

7. The film of claim 1, wherein the anchor coat layer has a compression modulus of not less than 3.0 kgf/mm² at 40°

C.

8. The film of claim 1, wherein the anchor coat layer comprises a polyester resin or a graft copolymer of a polyester and an acrylic polymer.

9. The film of claim 1, further comprising a sealant layer laminated on the inorganic deposited layer.

10. The film of claim 9, wherein the sealant layer is a polyolefin resin film having a compression modulus of not less than 8 kgf/mm² at 95°

C. and a Vicat softening point of not more than 145°

C., and the maximum shrinkage percentage of the gas barrier resin film after boiling treatment at 95°

C. for 30 minutes relative to the maximum shrinkage percentage of the polyamide film after boiling treatment at 95°

C. for 30 minutes is less than 70%.

11. The film of claim 9, further comprising an adhesive layer between the inorganic deposited layer and the sealant layer.

12. The film of claim 11, wherein the adhesive layer has a compression modulus of not less than 8.8 kgf/mm² at 40°

C.

13. The film of claim 1, having an oxygen permeability after boiling treatment at 95°

C. for 30 minutes of not more than 15 cc/m² ·

atm·

day.

14. The film of claim 1, having a water vapor transmission after boiling treatment at 95°

C. for 30 minutes of not more than 10 g/m² ·

day.

15. The film of claim 1, having a peeling strength of not less than 500 g/15 mm as measured by a 90°

peel test after heat sealing two sheets of said film at 2 kgf/cm² for one second at not more than 160°

C.

16. The film of claim 1, having a blocking property as measured according to ASTM-D 1893-67 of not more than 10 g/20 mm.