US4865902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayered polyolefin high shrinkage, low-shrink force shrink film
Assignee: Bemis Clysar Inc
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Filing: 1988-03-08
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Granted: 1989-09-12
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Expires: 2008-03-08
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
- 👤 Ralph C. Golike
- 👤 Robert W. Thies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:43
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
118 words
A multi-layer, heat shrinkable film comprising: (a) 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 core layer consisting essentially of a material selected from the group consisting of ethylene/acid copolymers and related ionomers; ethylene/acid/acrylate terpolymers and related ionomers; 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, said multilayer heat shrinkable film having been uniformly oriented at a temperature above the melting point of the core layer.
Claim 2
Dependent Claim
118 words
A multi-layer, heat shrinkable film comprising: (a) 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 core layer consisting essentially of a material selected from the group consisting of ethylene/acid copolymers and related ionomers; ethylene/acid/acrylate terpolymers and related ionomers; 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, said multilayer heat shrinkable film having been uniformly oriented at a temperature above the melting point of the core layer.
Claim 3
Dependent Claim
13 words
The film of claim 1 where the outer layer is a propylene/ethylene copolymer.
Claim 4
Dependent Claim
15 words
The film of claim 2 where the propylene/ethylene copolymer contains about 1 to 4% ethylene.
Claim 5
Dependent Claim
49 words
The film of claim 1 wherein the core layer consists essentially of a material 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; or any combination thereof.
Claim 6
Dependent Claim
16 words
The film of claim 4 where the core layer is an ionomer or blend of ionomers.
Claim 7
Dependent Claim
27 words
The film of claim 5 where the core layer is a copolymer of ethylene and 9 to 18 weight percent methacrylic acid neutralized up to about 60%.
Claim 8
Dependent Claim
29 words
The film of claim 5 wherein the core layer is a copolymer of ethylene and about 27 to about 42 weight percent methacrylic acid neutralized up to about 90%.
Claim 9
Dependent Claim
13 words
The film of claim 4 where the outer layer is a propylene/ethylene copolymer.
Claim 10
Dependent Claim
39 words
The film of claim 1 where the outer layer is a propylene/ethylene copolymer containing about 1 to 4% ethylene and the core layer is a copolymer of ethylene and 9 to 18% methacrylic acid neutralized up to about 60%.
Claim 11
Dependent Claim
43 words
The film of claim 1 where the outer layer is a propylene/ethylene copolymer containing about 1 to 4% ethylene and the core layer is a copolymer of ethylene and about 27 to about 42 weight percent methacrylic acid neutralized up to about 90%.
Claim 12
Dependent Claim
21 words
The film of claim 1 where the core layer comprises about 60 to 90% of the total thickness of the film.
Claim 13
Dependent Claim
33 words
The film of claim 1 which has a layer of adhesive resin between the outer layer and the core layer capable of increasing the adhesion between the outer layer and the core layer.
Claim 14
Dependent Claim
22 words
The film of claim 15 where the adhesive resin is selected from ethylene vinyl acetate copolymers, ethylene/ester copolymers and anhydride grafted polyolefins.
Claim 15
Dependent Claim
17 words
The film of claim 13 where the adhesive resin is a copolymer of ethylene with methyl acrylate.
Claim 16
Dependent Claim
21 words
The film of claim 14 where the adhesive resin is a copolymer of ethylene with about 20 to 24% methyl acrylate.
Claim 17
Dependent Claim
25 words
The film of claim 15 where the core layer is a copolymer of ethylene and about 15% methacrylic acid which has been neutralized about 58%.
Claim 18
Dependent Claim
25 words
The film of claim 15 where the core layer is a copolymer of ethylene and about 10% methacrylic acid which has been neutralized about 54%.
Claim 19
Dependent Claim
25 words
The film of claim 15 where the core layer is a copolymer of ethylene and about 15% methacrylic acid which has been neutralized about 29%.
Claim 20
Dependent Claim
29 words
The film of claim 16 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 21
Dependent Claim
29 words
The film of claim 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 22
Dependent Claim
29 words
The film of claim 18 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 23
Dependent Claim
61 words
A multilayer, heat-shrinkable film comprising: (a) two outer layers of a blend of propylene/ethylene copolymer, polypropylene homopolymer, and linear low density polyethylene; (b) a core layer of ethylene/methacrylic acid copolymer containing about 15 weight percent copolymerized methacrylic acid, neutralized about 30% with sodium; and (c) two adhesive layers of a blend of ethylene methyl acrylate copolymer and ultra low density polyethylene.
Claim 24
Dependent Claim
61 words
A multilayer, heat-shrinkable film comprising: (a) two outer layers of a blend of propylene/ethylene copolymer, polypropylene homopolymer, and linear low density polyethylene; (b) a core layer of ethylene/methacrylic acid copolymer containing about 15 weight percent copolymerized methacrylic acid, neutralized about 30% with sodium; and (c) two adhesive layers of a blend of ethylene methyl acrylate copolymer and ultra low density polyethylene.
Claim 25
Dependent Claim
10 words
A packaging material comprising a film according to claim 1.
Claim 26
Dependent Claim
48 words
A method of making a heat-shrinkable film of claim 1 comprising uniformly stretching a multi-layer film comprising said outer layers and said core layer at a temperature at or above the orientation temperature of the material in said outer layers but below the melting temperature of said materials.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |