US4436788A
Expired / Lapsed
US
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Composite stretch wrap film
Assignee: Tyco Plastics Services AG
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Filing: 1982-12-01
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Granted: 1984-03-13
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Expires: 2002-12-01
Abstract
Abstract A composition adapted for processing into stretch wrap film. The composition comprises between about 40 and about 90% by weight of a high molecular weight copolymer of ethylene and vinyl acetate containing between about 4 and about 25% by weight of repeating units derived from vinyl acetate and having a melt index of between about 0.1 and about 4.0. The composition further comprises between about 8 and about 55% by weight of a linear copolymer of ethylene and a higher alkene. Such linear copolymer has a specific gravity of between about 0.917 and about 0.945. The invention further includes stretch wrap film, a method of producing stretch wrap film of differential cling properties, and a composite film constituted of a layer of the aforesaid ethylene vinyl acetate copolymer and a layer of the liner copolymer of ethylene and a higher alkene.
Inventors
- 👤 Barry A. Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:25
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0807; C08L23/0815; B; B32; B32B; B32B27/00; B32B27/32; C08J; C08J5/00; C08J5/18; C08L23/0846; C08L23/0853; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/08; C08L2205/00; C08L2205/03; C08L23/18; C08L23/20; C08L23/22; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31786; Y10T428/31797; Y10T428/31801; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
107 words
A composite film comprising: a first layer comprising at least about 90% by weight of high molecular weight copolymer of ethylene and vinyl acetate containing between about 4 and about 25% by weight of repeating units derived from vinyl acetate and having a melt index of between about 0.1 and about 4.0 and a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene and microcrystalline wax; and a second layer lamellarly adhered to said first layer and comprising at least about 90% by weight of a linear low density polyethylene having a specific gravity of between about 0.917 and about 0.945.
Claim 2
Dependent Claim
107 words
A composite film comprising: a first layer comprising at least about 90% by weight of high molecular weight copolymer of ethylene and vinyl acetate containing between about 4 and about 25% by weight of repeating units derived from vinyl acetate and having a melt index of between about 0.1 and about 4.0 and a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene and microcrystalline wax; and a second layer lamellarly adhered to said first layer and comprising at least about 90% by weight of a linear low density polyethylene having a specific gravity of between about 0.917 and about 0.945.
Claim 3
Dependent Claim
76 words
A composite as set forth in claim 1 further comprising a third layer lamellarly adhered to said second layer on the side thereof opposite said first layer, said third layer comprising at least about 90% by weight of a high molecular weight copolymer of ethylene and vinyl acetate containing between about 4 and about 25% by weight of repeating units derived from vinyl acetate and having a melt index of between about 0.1 and about 4.0.
Claim 4
Dependent Claim
25 words
A composite film as set forth in claim 1 wherein said first layer contains between about 0.5 and about 6% by weight of said tackifier.
Claim 5
Dependent Claim
18 words
A composite film as set forth in claim 3 wherein said tackifier comprises a low molecular weight polyisobutene.
Claim 6
Dependent Claim
24 words
A composite film as set forth in claim 1 wherein said first layer further comprises a monoester of a fatty acid and a polyol.
Claim 7
Dependent Claim
25 words
A composite film as set forth in claim 5 wherein said first layer contains between about 0.25% and about 3% by weight of said monoester.
Claim 8
Dependent Claim
15 words
A composite film as set forth in claim 6 wherein said monoester comprises glycerol monooleate.
Claim 9
Dependent Claim
15 words
A composite film as set forth in claim 5 wherein said monoester comprises glycerol monooleate.
Claim 10
Dependent Claim
34 words
A composite film as set forth in claim 2 wherein said third layer further comprises a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax.
Claim 11
Dependent Claim
25 words
A composite film as set forth in claim 9 wherein said third layer contains between about 0.5% and about 6% by weight of said tackifier.
Claim 12
Dependent Claim
24 words
A composite film as set forth in claim 10 wherein said third layer further comprises a monoester of a fatty acid and a polyol.
Claim 13
Dependent Claim
39 words
A composite film as set forth in claim 11 wherein said first and third layers each contain between about 0.5 and about 6% by weight of said tackifier and between about 0.25 and about 3% by weight glycerol monooleate.
References Cited (Backward Citations)
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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) | 1987-03-13 | 1987-09-12 | 1988-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-13 | 1991-09-12 | 1992-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-13 | 1995-09-12 | 1996-03-13 | $7700.00 | Window Closed / Lapsed |