Laminate structure and production of the same

• US 4,640,870 A
• Filed: 04/30/1985
• Issued: 02/03/1987
• Est. Priority Date: 05/09/1984
• Status: Expired due to Term

• Current Assignee: Kuraray Company Limited
• Original Assignee: Kuraray Company Limited
• Inventors: Akazawa, Toshiyuki, Tanaka, Yoshinari, Okaya, Takuji
• Primary Examiner(s): Buffalow, Edith
• Application Number:
  US06/728,747
• Time in Patent Office: 644 Days
• Field of Search: 428/349, 428/483, 428/522, 428/35, 525/221, 525/207
• US Class Current: 428/483
• CPC Class Codes: B32B 2307/73 Hydrophobic
• 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 27/36 comprising polyesters
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

There is provided a laminate structure comprising (A) a layer of saponified product of ethylene-vinyl acetate copolymer and (B) a layer of hydrophobic thermoplastic resin, with (C) a bonding interlayer placed therebetween which comprises a composition of (X) a polymer of ethylene-acrylate ester-ethylenic unsaturated carboxylic acid or anhydride thereof and (Y) a polymer of ethylene-acrylate ester.

The laminate is superior in interlaminar adhesion and gas barrier properties, and is suitable for food packaging.

Claims

1. A laminate structure comprising (a) a layer of a saponified product of an ethylene-vinyl acetate copolymer containing 20 to 55 mole % of ethylene and having a degree of saponification of at least 90 mole % and (B) a layer of hydrophobic thermoplastic resin, with (C) a bonding interlayer placed therebetween which comprises a composition of (X) a polymer of ethylene, an acrylic acid ester, and an ethylenically unsaturated carboxylic acid or anhydride thereof and (Y) a polymer of ethylene and an acrylic acid ester, said polymers (X) and (Y) being formulated so that the following formulas (I), (II), (III), and (IV) are satisfied:

space="preserve" listing-type="equation">|Vx-Vy|≦

0.15 (I)

space="preserve" listing-type="equation">0.10≦

Vx·

Wx+Vy·

Wy≦

0.45 (II)

space="preserve" listing-type="equation">0.03≦

CxWx≦

1 (III)

space="preserve" listing-type="equation">0.05≦

Wx/Wy≦

10 (IV)

where;

Vx;

content (in weight fraction) of acrylic acid ester in polymer (X)

Vy;

content (in weight fraction) of acrylic acid ester in polymer (Y),

Cx;

content (in meq/g) of carboxyl group of ethylenically unsaturated carboxylic acid or anhydride thereof in polymer (X),

Wx;

quantity (in weight fraction) of polymer (X), and

Wy;

quantity (in weight fraction) of polymer (Y).

2. A laminate structure as set forth in claim 1 wherein said hydrophobic thermoplastic resin is a saturated polyester resin.