Multiple layer packaging sheet material

• US 5,002,811 A
• Filed: 01/12/1990
• Issued: 03/26/1991
• Est. Priority Date: 11/29/1985
• Status: Expired due to Term

• Current Assignee: Pechiney Plastic Packaging Incorporated (Rio Tinto Limited)
• Original Assignee: American National Can Company
• Inventors: Genske, Roger P., Bauer, Frank T., Kim, Yong J.
• Primary Examiner(s): Buffalow, Edith
• Application Number:
  US07/464,279
• Time in Patent Office: 438 Days
• Field of Search: 428/483, 428/522, 428/35.4
• US Class Current: 428/35.4
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/185 comprising six or more components, i.e. each component being counted once for each time it is present, e.g. in a layer
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: C08L 23/04 Homopolymers or copolymers of ethene
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 23/12 Polypropene
• CPC Class Codes: C08L 23/22 Copolymers of isobutene; Butyl rubber ; Homo- or copolymers of other iso-olefins
• 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 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: C08L 2666/08 Homopolymers or copolymers according to C08L7/00 - C08L21/00; Derivatives thereof
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 53/025 modified
• CPC Class Codes: Y10T 428/1341 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 : Ester, halide or nitrile of addition polymer

Abstract

A multiple layer sheet material comprising a first layer 12 of vinylidene chloride copolymer having a first softening temperature. A second polymeric sealant layer 14 has a second softening temperature no more than about 50° C. less than the first softening temperature. An optional third layer 16 between the first and second layers has a third softening temperature greater than either of the first and second softening temperatures and comprises a polyethylene terephthalate composition. A fourth polymeric layer 18 has a fourth softening temperature greater than the first and second softening temperatures. The first layer is positioned between the third and fourth layers. A fifth impact layer 20 is positioned between layers 14 and 16. The composition of the impact layer 20 comprises, as a first component, a base polymer drawn from the same family of polymers as a major polymeric component of the second sealant layer, and, as a second component, a polymeric composition providing elastomeric properties to the impact layer and increased shock tolerance to the multiple layer sheet material. The disclosure also teaches the use of the sheet materials in fabrication of packages and teaches methods of fabricating both the sheet materials and the packages.

Claims

1. A multiple layer sheet material, comprising:

(a) a first layer of vinylidene chloride copolymer;

(b) a second sealant layer comprising at least 40% by weight polypropylene;

(c) a third impact layer between said first and second layers, the composition of said impact layer comprising (i) as a first component, a polypropylene polymer, and (ii) as a second component, a polymeric composition providing elastomeric properties to said impact layer and increased shock tolerance to said multiple layer sheet material; and

(d) a fourth layer of polyethylene terephthalate, said first layer being between said third and fourth layers.

2. A multiple layer sheet materials as in claim 1 wherein said second component of said third layer is selected from the group consisting of polyisobutylene and ethylene butene-1 copolymers containing 85% to 95% ethylene.

3. A multiple layer sheet material as in claim 1 or 2 wherein said second layer comprises a mixture of polypropylene and a polyethylene having a density of at least about 0.93.

4. A multiple layer sheet material as in claim 1 or 2 and including, as a third component of said third impact layer, a second polymeric composition providing elastomeric properties to said third impact layer and shock tolerance to said multiple layer sheet material.

5. A package made with a sheet material of claim 1 or 2.

6. A package made with a sheet material of claim 3.

7. A package made with a sheet material of claim 4.