Films, sheets, laminates and molded articles having gas barrier properties

• US 4,562,118 A
• Filed: 10/24/1984
• Issued: 12/31/1985
• Est. Priority Date: 01/29/1982
• Status: Expired due to Term

• Current Assignee: TOYO Seikan Kaisha Limited
• Original Assignee: TOYO Seikan Kaisha Limited
• Inventors: Yamada, Muneki, Maruhashi, Yoshitsugu, Kano, Fumio, Hirata, Sadao
• Primary Examiner(s): Lieberman, Allan M.
• Application Number:
  US06/664,308
• Time in Patent Office: 433 Days
• Field of Search: 428/412, 428/423.5, 428/423.7, 428/424.2, 428/424.4, 428/474.4, 428/475.2, 428/475.8, 428/476.3, 428/476.9, 428/480, 428/483, 428/500, 428/515 , 428/523, 428/514, 428/522, 525/58
• US Class Current: 428/412
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31906 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31938 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

Disclosed is a resin composition excellent in its drawability, which comprises (A) a saponified ethylene-vinyl ester copolymer having an ethylene content of 20 to 55 mole % and a saponification degree of at least 95%, (B) a saponified ethylene-vinyl ester copolymer having an ethylene content of 25 to 60 mole % and a saponification degree of at least 90%, the ethylene content of the saponified copolymer (B) being higher by at least 3 mole % than the ethylene content of the saponified copolymer (A), and (C) a polyamide, wherein the weight ratio of the saponified copolymer (A) to the saponified copolymer (B) is in the range of from 90/10 to 10/90 and the weight ratio of the sum of the saponified copolymers (A) and (B) to the polyamide (C) is in the range of from 95/5 to 5/95. The resin compositions have excellent gas barrier properties and can be molded into films or sheets or laminated with other film-forming materials. Molded articles such as cups and other vessels having gas barrier properties can be obtained by molding the laminated films prepared from the resin compositions.

Claims

1. A film or sheet obtained by heat-molding a resin composition having excellent drawability which comprises (A) a saponified ethylene-vinyl ester copolymer having an ethylene content of 20 to 55 mole% and a saponification degree of at least 95%, (B) a saponified ethylene-vinyl ester copolymer having an ethylene content of 25 to 60 mole% and a saponification degree of at least 90%, the ethylene content of the saponified copolymer (B) being higher by at least 3 mole% than the ethylene content of the saponified copolymer (A), and (C) a polyamide having a film-forming molecular weight, wherein the weight ratio of the saponified copolymer (A) to the saponified copolymer (B) is in the range of from 90/10 to 10/90 and the weight ratio of the sum of the saponified copolymers (A) and (B) to the polyamide (C) is in the range of from 95/5 to 5/95, into a film or sheet.

2. The film or sheet of claim 1 wherein the saponified copolymer (A) is a saponified ethylene-vinyl ester copolymer having an ethylene content of 25 to 50 mole% and the saponified copolymer (B) is a saponified ethylene-vinyl ester copolymer having an ethylene content of 30 to 55 mole%, and the ethylene content of the saponified copolymer (B) is higher by at least 5 mole% than the ethylene content of the saponified copolymer (A).

3. The film or sheet of claim 1 wherein the polyamide (C) is a homopolyamide or copolyamide having 3 to 30 amides groups per 100 carbon atoms in the polyamide, or a blend thereof.

4. The film or sheet of claim 1 wherein the polyamide (C) is a copolyamide comprising nylon 6 and nylon 6,6 at a weight ratio of from 99/1 to 70/30.

5. The film or sheet of claim 1 wherein the saponified copolymers (A) and (B) are contained at a weight ratio of from 80/20 to 20/80.

6. The film or sheet of claim 1 wherein the weight ratio of the total amount of the saponified copolymers (A) and (B) to the amount of the polyamide (C) is in the range of from 80/20 to 5/95.

7. The film or sheet of claim 1 wherein said polyamide (C) has a relative viscosity in the range of from 1.2 to 6.0 as measured at 20°

C. with respect to a solution of 1 gram of the polyamide in 100 cc of 98% sulfuric acid.

8. The film or sheet of claim 2 wherein the saponified copolymers (A) and (B) are contained at a weight ratio of from 80/20 to 20/80 and wherein the weight ratio of the total amount of the saponified copolymers (A) and (B) to the amount of the polyamide (C) is in the range of from 80/20 to 5/95.

9. The film or sheet of claim 8 wherein the saponified copolymers (A) and (B) are contained at a weight ratio of about 50/50.

16. The film or sheet of claim 1 which is drawn in at least one direction.

17. The film or sheet of claim 1 which is monoaxially drawn.

18. The film or sheet of claim 1 which is biaxially drawn.

10. A laminated film comprising as one layer thereof a resin composition comprising (A) a saponified ethylene-vinyl ester copolymer having an ethylene content of 20 to 55 mole% and a saponification degree of at least 95%, (B) a saponified ethylene-vinyl ester copolymer having an ethylene content of 25 to 60 mole% and a saponification degree of at least 90%, the ethylene content of the saponified copolymer (B) being higher by at least 3 mole% than the ethylene content of the saponified copolymer (A), and (C) a polyamide having a film-forming molecular weight, wherein the weight ratio of the saponified copolymer (A) to the saponified copolymer (B) is in the range of from 90/10 to 10/90 and the weight ratio of the sum of the saponified copolymers (A) and (B) to the polyamide (C) is in the range of from 95/5 to 5/95, and a second layer of a material prepared from a polymer selected from the group consisting of polyethylene, polypropylene, ethylene-vinyl propylene copolymers, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ion-crosslinked olefin copolymers, polyethylene terephthalate, polycarbonates, polystyrene, polyvinyl chloride, polyvinylidene chloride, methacrylic resins, and poly-4-methylpentene-1.

13. A molded article formed by molding the laminated film of claim 10.

14. The molded article of claim 13 which is in the form of a vessel.

11. A laminated film which comprises an intermediate layer of a resin composition comprising (A) a saponified ethylene-vinyl ester copolymer having an ethylene content of 20 to 55 mole% and a saponification degree of at least 95%, (B) a saponified ethylene-vinyl ester copolymer having an ethylene content of 25 to 60 mole% and a saponification degree of at least 90%, the ethylene content of the saponified copolymer (B) being higher by at least 3 mole%, than the ethylene content of the saponified copolymer (A), and (C) a polyamide having a film-forming molecular weight, wherein the weight ratio of the saponified copolymer (A) to the saponified copolymer (B) is in the range of from 90/10 to 10/90 and the weight ratio of the sum of the saponified copolymers (A) and (B) to the polyamide (C) is in the range of from 95/5 to 5/95, and inner and outer layers on either side of said intermediate layer formed of a humidity-resistant resin selected from the group consisting of low density polyethylene, medium density polyethylene, high density polyethylene, isotactic polypropylene, crystalline ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ion-crosslinked olefin copolymers, polyethylene terephthalate, polycarbonates, polystyrene, polyvinyl chloride, polyvinylidene chloride, methacrylic resins and poly-4-methylpentene-1.

12. A molded article formed by molding the laminated film of claim 11.

15. The molded article of claim 12 which is in the form of a vessel.