US4762748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer film with better layer adhesion
Assignee: Cryovac LLC
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Filing: 1986-06-30
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Granted: 1988-08-09
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Expires: 2006-06-30
Abstract
Abstract A pasteurizable and/or cook-in shrink film is provided with good interlaminar adhesion and good orientability, and characterized by the presence of ethylene alkyl acrylate copolymer in shrink and abuse layers, in adhesive layers, or both. An associated method for making the film is also provided that includes coextrusion of the multilayer film, optional irradiation, and orientation.
Inventors
- 👤 Timothy T. Oberle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:08
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/30; B32B27/304; B32B27/308; B32B7/00; B32B7/04; B32B7/12; B32B2305/00; B32B2305/72; B32B2307/00; B32B2307/50; B32B2307/514; B32B2310/00; B32B2310/14; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
198 words
A multilayer shrink film, comprising: (a) a first or sealing layer comprising a polymeric material selected from the group consisting of a propylene ethylene copolymer, an ionomer, a blend of a linear low density polyethylene and an ionomer, and a blend of a linear low density polyethylene and an ethylene acrylic acid copolymer; (b) a second shrink layer, melt bonded to said first layer; (c) a third adhesive layer, melt bonded to said second layer, which comprises a chemically modified ethylene alkyl acrylate copolymer or ethylene vinyl acetate copolymer; (d) a fourth barrier layer, melt bonded to said third layer, which comprises an ethylene vinyl alcohol copolymer; (e) a fifth adhesive layer as in said third layer, melt bonded to said fourth layer; and (f) a sixth abuse layer, melt bonded to said fifth layer; wherein ethylene alkyl acrylate copolymer is present in either the adhesive layers, or as a component blended with linear low density polyethylene in the shrink and abuse layers; and wherein the second and sixth layers comprise a blend of a linear low density polyethylene and a polymeric material selected from the group consisting of ethylene alkyl acrylate copolymer and ethylene vinyl acetate copolymer.
Claim 2
Dependent Claim
198 words
A multilayer shrink film, comprising: (a) a first or sealing layer comprising a polymeric material selected from the group consisting of a propylene ethylene copolymer, an ionomer, a blend of a linear low density polyethylene and an ionomer, and a blend of a linear low density polyethylene and an ethylene acrylic acid copolymer; (b) a second shrink layer, melt bonded to said first layer; (c) a third adhesive layer, melt bonded to said second layer, which comprises a chemically modified ethylene alkyl acrylate copolymer or ethylene vinyl acetate copolymer; (d) a fourth barrier layer, melt bonded to said third layer, which comprises an ethylene vinyl alcohol copolymer; (e) a fifth adhesive layer as in said third layer, melt bonded to said fourth layer; and (f) a sixth abuse layer, melt bonded to said fifth layer; wherein ethylene alkyl acrylate copolymer is present in either the adhesive layers, or as a component blended with linear low density polyethylene in the shrink and abuse layers; and wherein the second and sixth layers comprise a blend of a linear low density polyethylene and a polymeric material selected from the group consisting of ethylene alkyl acrylate copolymer and ethylene vinyl acetate copolymer.
Claim 3
Dependent Claim
16 words
The film of claim 1 wherein said ethylene alkyl acrylate copolymer comprises ethylene butyl acrylate copolymer.
Claim 4
Dependent Claim
25 words
The film of claim 1 wherein the film is cross-linked by irradiation at a dosage sufficient to render the film delamination resistant under cook-in conditions.
Claim 5
Dependent Claim
23 words
The film of claim 1 where the film is cross-linked by irradiation at a dosage of between about 3 and about 12 megarads.
Claim 6
Dependent Claim
39 words
The film of claim 1 wherein said second and sixth layers comprises between about 20% and 80% by weight of a linear low density polyethylene, and between about 20% and 80% by weight of an ethylene alkyl acrylate copolymer.
Claim 7
Dependent Claim
10 words
The film of claim 1 wherein said film is oriented.
Claim 8
Dependent Claim
25 words
The film of claim 8 wherein said film is biaxially oriented to a stretch ratio of between about 5 to 1 and 15 to 1.
Claim 9
Dependent Claim
23 words
The film of claim 1 wherein said first layer comprises a propylene-ethylene random copolymer having an ethylene content of about 1-6% by weight.
Claim 10
Dependent Claim
11 words
The film of claim 1 wherein the film is chemically cross-linked.
References Cited (Backward Citations)
US4495249A
Cited
US4615926A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-09 | 1992-02-08 | 1992-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-09 | 1996-02-08 | 1996-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-09 | 2000-02-08 | 2000-08-09 | $7700.00 | Window Closed / Lapsed |