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EP0229715A2
Expired / Lapsed
EP
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Multilayered polyolefin high shrinkage low-shrink force shrink film
Assignee: Bemis Clysar Inc
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Filing: 1987-01-14
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Granted: —
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Expires: 2007-01-14
Abstract
Abstract A multi-layered, heat shrinkable film is disclosed which possesses one or two outer layers of a polyolefin and a core layer of material having a melting point below the temperature required to orient the material of the outer layer or layers, the core layer comprising 50 to 95% of the overall thickness of the film.
Inventors
- 👤 Robert Wayne Thies
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 15:26
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/08; B32B7/00; B32B7/04; B32B7/12; B32B38/00; B32B38/0012; B32B2038/0028; B32B2307/00; B32B2307/70; B32B2307/732; B32B2307/734; B32B2307/736; B32B2553/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
120 words
A multi-layer, heat-shrinkable film comprising: (a) one or two outer layers of material selected from the group consisting of polyethylene, polypropylene, propylene/ethylene copolymers and blends thereof, (b) a core layer of material having a melting point below the temperature required to orient the material of the outer layer or layers, said material being selected from the group consisting of ethylene/acid copolymers and related ionomers; ethylene/acid/acrylate terpolymers and related ionomers; blends of any of the above with up to about 50% ethylene vinyl acetate; blends of ethylene/ester copolymers with up to about 50% ethylene vinyl acetate; and combinations of the above materials, said core layer having a thickness comprising about 50 to 95% of the total thickness of the heat-shrinkable film.
Claim 2
Dependent Claim
120 words
A multi-layer, heat-shrinkable film comprising: (a) one or two outer layers of material selected from the group consisting of polyethylene, polypropylene, propylene/ethylene copolymers and blends thereof, (b) a core layer of material having a melting point below the temperature required to orient the material of the outer layer or layers, said material being selected from the group consisting of ethylene/acid copolymers and related ionomers; ethylene/acid/acrylate terpolymers and related ionomers; blends of any of the above with up to about 50% ethylene vinyl acetate; blends of ethylene/ester copolymers with up to about 50% ethylene vinyl acetate; and combinations of the above materials, said core layer having a thickness comprising about 50 to 95% of the total thickness of the heat-shrinkable film.
Claim 3
Dependent Claim
15 words
A film of Claim l where the or each outer layer is a propylene/ethylene copolymer.
Claim 4
Dependent Claim
15 words
A film of Claim 2 where the propylene/ethylene copolymer contains about l to 4% ethylene.
Claim 5
Dependent Claim
100 words
A film of any one of Claims l to 3 where the core layer is selected from copolymers of ethylene and acrylic acid or methacrylic acid, and corresponding ionomers; terpolymers of ethylene, acrylic acid or methacrylic acid, and an alkyl acrylate or methacrylate, and corresponding ionomers; blends of up to about 50% ethylene vinyl acetate with (i) copolymers of ethylene and acrylic acid or methacrylic acid, or corresponding ionomers; (ii) terpolymers of ethylene, acrylic acid or methacrylic acid, and alkyl acrylate or methacrylate; or corresponding ionomers; (iii) copolymers of ethylene with alkyl acrylate or alkyl methacrylate; or any combination thereof.
Claim 6
Dependent Claim
16 words
A film of Claim 4 where the core layer is an ionomer or blend of ionomers.
Claim 7
Dependent Claim
25 words
A film of Claim 5 where the core layer is a copolymer of ethylene and 9 to l8% methacrylic acid neutralized up to about 60%.
Claim 8
Dependent Claim
15 words
A film of Claim 4 where the or each outer layer is a propylene/ethylene copolymer.
Claim 9
Dependent Claim
41 words
A film of Claim l where the or each outer layer is a propylene/ethylene copolymer containing about l to 4% ethylene and the core layer is a copolymer of ethylene and 9 to l8% methacrylic acid neutralized up to about 60%.
Claim 10
Dependent Claim
26 words
The film of any one of Claims l to 8 where the core layer comprises about 60 to 90% of the total thickness of the film.
Claim 11
Dependent Claim
16 words
l0. The film of any one of Claims l to 9 which has two outer layers.
Claim 12
Dependent Claim
40 words
The film of any one of Claims l to 10 which has a layer of adhesive resin between the or each outer layer and the core layer capable of increasing the adhesion between the outer layer(s) and the core layer.
Claim 13
Dependent Claim
22 words
The film of Claim 11 where the adhesive resin is selected from ethylene vinyl acetate copolymers, ethylene/ester copolymers and anhydride grafted polyolefins.
Claim 14
Dependent Claim
16 words
The film of Claim 11 where the adhesive resin is a copolymer of ethylene with methylacrylate.
Claim 15
Dependent Claim
20 words
The film of Claim 13 where the adhesive resin is a copolymer of ethylene with about 20 to 24% methylacrylate.
Claim 16
Dependent Claim
30 words
The film of any one of Claims 1 to 14 where the core layer is a copolymer of ethylene and about 15% methacrylic acid which has been neutralized about 58%.
Claim 17
Dependent Claim
30 words
The film of any one of Claims 1 to 14 where the core layer is a copolymer of ethylene and about 10% methacrylic acid which has been neutralized about 54%.
Claim 18
Dependent Claim
30 words
The film of any one of Claims 1 to 14 where the core layer is a copolymer of ethylene and about 15% methacrylic acid which has been neutralized about 29%.
Claim 19
Dependent Claim
34 words
The film of any one of Claims 11 to 17 where each of the outer layers and each of the layers of adhesive resin comprise about 5% of the total thickness of the film.
Claim 20
Independent Claim
65 words
A method of making a heat-shrinkable film of any one of Claims 1 to 18 comprising stretching a multi-layer film comprising said one or two outer layers and said core layer at a temperature at or above the orientation temperature of the material in said one or two outer layers but below the melting temperature of said material(s) in said one or two outer layers.
Claim 21
Dependent Claim
15 words
A packaging material comprising a film according to any one of Claims 1 to 18.
References Cited (Backward Citations)
No citation records indexed.
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