Heat-sterilizable laminate films

• US 4,599,276 A
• Filed: 10/22/1984
• Issued: 07/08/1986
• Est. Priority Date: 11/09/1983
• Status: Expired due to Term

• Current Assignee: Cryovac Incorporated (Sealed Air)
• Original Assignee: W R Grace & Company Cryovac DIV
• Inventors: Martini, Francesco
• Primary Examiner(s): Buffalow, Edith
• Application Number:
  US06/663,650
• Time in Patent Office: 624 Days
• Field of Search: 428/35, 428/522, 428/520, 428/349
• US Class Current: 428/520
• CPC Class Codes: A61J 1/10 Bag-type containers
• CPC Class Codes: B32B 2305/72 Cured, e.g. vulcanised, cross-linked
• CPC Class Codes: B32B 2307/308 Heat stability
• CPC Class Codes: B32B 2439/80 Medical packaging
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• 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 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/1334 Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/31928 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

A heat-sterilizable laminate film especially useful for making disposible pouches for sterile injectable compositions comprises an ethylene-vinyl acetate copolymer layer and on either side of the said layer a layer of a propylene-ethylene copolymer which may contain an impact modifier. The laminate may be cross-linked by irradiation.

Claims

1. A heat sterilizable laminate consisting of a layer of an ethylene-vinyl acetate copolymer containing 18 to 40 percent by weight of vinyl acetate units said layer being substantially unoriented and, on each side of the said layer, a layer of 60 to 100 percent by weight of a propylene-ethylene copolymer containing 2 to 4.5 percent by weight of ethylene units, and 40 to 0 percent by weight of an impact modifier containing 30 to 63 parts by weight of an ethylene-propylene elastomer or ethylenepropylene-diene elastomer having an ethylene content of 55 to 70 weight percent and 70 to 37 parts by weight of a thermoplastic ethylene-vinyl acetate copolymer containing 9 to 40 percent of vinyl acetate units.

2. A laminate according to claim 1 consisting of the said layer of an ethylene-vinyl acetate copolymer having on each side a layer of the said propylene-ethylene copolymer containing no impact modifier, the polymers of the said laminate being cross-linked by irradiation.

3. A laminate according to claim 1 consisting of five layers, namely a core layer of the said ethylene-vinyl acetate copolymer, two outer layers of the said propylene-ethylene copolymer, and two layers of adhesive between the said outer layers and the said core layer.

4. A laminate according to any one of claims 2 and 3 in which the said ethylene-vinyl acetate copolymer contains 18 to 30 percent by weight of vinyl acetate units and has a melt flow index of 0.7 to 7 g/10 mins., a density of 0.930 to 0.970 g/cm³, and a Vicat softening point of 40°

to 80°

C.

5. A laminate according to any one of claims 1, 2, and 3 in which the propylene-ethylene copolymer has a melt flow index of 3 to 7 g/10 mins., a density of 0.890 to 0.910 g/cm³, and a Vicat softening point 120°

to 130°

C.