Patent US4425268A successfully refreshed from Google Patents.
US4425268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymer blend composition for stretch wrap film
Assignee: Amcor Flexibles North America Inc
•
Filing: 1980-02-02
•
Granted: 1984-01-10
•
Expires: 2000-02-02
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 linear 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 20:31
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/322; C; C08; C08J; C08J5/00; C08J5/18; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0807; C08L23/0815; C08L23/0846; C08L23/0853; B32B2323/00; B32B2323/04; B32B2323/046; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/08; C08L2205/00; C08L2205/03; C08L23/18; C08L23/20; C08L23/22
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
119 words
A composition adapted for processing into a stretch wrap film comprising: 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, between about 8 and about 55% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.945, and between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax.
Claim 2
Dependent Claim
119 words
A composition adapted for processing into a stretch wrap film comprising: 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, between about 8 and about 55% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.945, and between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax.
Claim 3
Dependent Claim
17 words
A composition as set forth in claim 1 wherein said tackifier comprises a low molecular weight polyisobutene.
Claim 4
Dependent Claim
23 words
A composition as set forth in claim 1 further comprising between about 0.1 and about 2.0% by weight of an alkali metal stearate.
Claim 5
Dependent Claim
28 words
A composition as set forth in claim 3 further comprising between about 0.25 and about 3% by weight of a monoester of a fatty acid and a polyol.
Claim 6
Dependent Claim
25 words
A composition as set forth in claim 4 wherein said ester is selected from the group consisting of esters of sorbitan and esters of glycerol.
Claim 7
Dependent Claim
14 words
A composition as set forth in claim 5 wherein said ester comprises glycerol monooleate.
Claim 8
Dependent Claim
23 words
A composition as set forth in claim 1 wherein said linear copolymer has a specific gravity of between about 0.917 and about 0.926.
Claim 9
Dependent Claim
142 words
A composition adapted for processing into a stretch wrap film comprising: between about 50 and about 70% by weight of a 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 between about 0.1 and about 4.0, between about 25% and about 45% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.926, between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax, between about 0.25 and about 3% by weight of a monoester of a fatty acid and a polyol, and between about 0.1 and about 2% by weight of an alkali metal stearate.
Claim 10
Dependent Claim
142 words
A composition adapted for processing into a stretch wrap film comprising: between about 50 and about 70% by weight of a 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 between about 0.1 and about 4.0, between about 25% and about 45% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.926, between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax, between about 0.25 and about 3% by weight of a monoester of a fatty acid and a polyol, and between about 0.1 and about 2% by weight of an alkali metal stearate.
Claim 11
Dependent Claim
19 words
A composition as set forth in claim 8 which comprises between about 2 and about 4% by weight polyisobutene.
Claim 12
Dependent Claim
20 words
A composition as set forth in claim 9 which comprises between about 0.5 and about 1% by weight glycerol monooleate.
Claim 13
Dependent Claim
24 words
A composition as set forth in claim 9 or 10 comprising between about 0.2 and about 0.5% by weight of an alkali metal stearate.
Claim 14
Dependent Claim
115 words
A film prepared from a composition comprising: between about 40 and about 90% by weight of a high molecular weight copolymer of ethylene and vinyl acetate contaning 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, between about 8 and about 55% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.945, and between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax.
Claim 15
Dependent Claim
115 words
A film prepared from a composition comprising: between about 40 and about 90% by weight of a high molecular weight copolymer of ethylene and vinyl acetate contaning 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, between about 8 and about 55% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.945, and between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of a low molecular weight polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax.
Claim 16
Dependent Claim
17 words
A film as set forth in claim 12 wherein said tackier comprises a low molecular weight polyisobutene.
Claim 17
Dependent Claim
26 words
A film as set forth in claim 12 wherein said composition further comprises between about 0.1 and about 2.0% by weight of an alkali metal stearate.
Claim 18
Dependent Claim
31 words
A film as set forth in claim 14 wherein said composition further comprises between about 0.25 and about 3% by weight of a monoester of a fatty acid and a polyol.
Claim 19
Dependent Claim
25 words
A film as set forth in claim 15 wherein said ester is selected from the group consisting of esters of sorbitan and esters of glycerol.
Claim 20
Dependent Claim
14 words
A film as set forth in claim 16 wherein said ester comprises glycerol monooleate.
Claim 21
Dependent Claim
50 words
A film as set forth in claim 15 which exhibits differential cling properties as produced by passing only one side of the film through a corona discharge zone, whereby the side of the film not subjected to corona discharge exhibits greater cling properties than the side passed through said zone.
Claim 22
Dependent Claim
50 words
A film as set forth in claim 15 which exhibits differential cling properties as produced by passing only one side of the film through a corona discharge zone, whereby the side of the film not subjected to corona discharge exhibits greater cling properties than the side passed through said zone.
Claim 23
Dependent Claim
22 words
A film as set forth in claim 12 wherein said linear copolymer has a specific gravity of between 0.917 and about 0.926.
Claim 24
Dependent Claim
138 words
A film prepared from a composition comprising: between about 50 and about 70% by weight of a 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 between about 0.1 and about 4.0, between about 25 and about 45% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.926, between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax, between about 0.25 and about 3% by weight of a monoester of a fatty acid and a polyol, and between about 0.1 and about 2% by weight of an alkali metal stearate.
Claim 25
Dependent Claim
138 words
A film prepared from a composition comprising: between about 50 and about 70% by weight of a 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 between about 0.1 and about 4.0, between about 25 and about 45% by weight of a linear copolymer of ethylene and a higher alkene, said linear copolymer having a specific gravity of between about 0.917 and about 0.926, between about 0.5 and about 6% by weight of a tackifier selected from the group consisting of polyisobutene, polyterpenes, amorphous polypropylene, and microcrystalline wax, between about 0.25 and about 3% by weight of a monoester of a fatty acid and a polyol, and between about 0.1 and about 2% by weight of an alkali metal stearate.
Claim 26
Dependent Claim
21 words
A film as set forth in claim 21 wherein said composition comprises between about 2 and about 4% by weight polyisobutene.
Claim 27
Dependent Claim
21 words
A film as set forth in claim 22 wherein said composition comprises between 0.5 and about 1% by weight glycerol monooleate.
Claim 28
Dependent Claim
27 words
A film as set forth in claim 22 or 23 wherein said composition comprises between about 0.2 and about 0.5% by weight of an alkali metal stearate.
References Cited (Backward Citations)
US2448799A
Cited
US2935418A
Cited
US4076698A
Cited
US4076698B1
Cited
US3433573A
Cited
US3248359A
Cited
US3391044A
Cited
US3389016A
Cited
US3424735A
Cited
US3391070A
Cited
US3501363A
Cited
US3503859A
Cited
US3663663A
Cited
US3682767A
Cited
US3847728A
Cited
US3932563A
Cited
US3944709A
Cited
US4073782A
Cited
US4116914A
Cited
US4170304A
Cited
US4189420A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |