US4222913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stretch pallet wrap film materials
Assignee: Amcor Flexibles North America Inc
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Filing: 1978-11-16
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Granted: 1980-09-16
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Expires: 1998-11-16
Abstract
Abstract Improved stretch pallet wrap films are prepared from blend compositions comprising from approximately 79% to 98% by weight of a high molecular weight ethylene-vinyl acetate copolymer, from approximately 1% to 18% by weight of a polypropylene copolymer and from approximately 0.3% to 5% by weight of a tackifier agent which may be a glycerol mono fatty acid, a sorbitan mono fatty acid, castor oil or expoxidized soya, with the ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of between approximately 8% and 20% and the polypropylene copolymer having a refractive index substantially similar to that of the ethylene-vinyl acetate copolymer. Such films exhibit improved properties for the stretch wrapping of palletized loads of boxes, bags and the like.
Inventors
- 👤 Barry A. Cooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:13
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0846; C08L23/0853; C08L23/10; C08L23/14
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
127 words
A composition suitable for processing into a stretch wrap film comprising from approximately 79% to 98% by weight of a high molecular weight ethylene-vinyl acetate copolymer, from approximately 1% to 18% by weight of a polypropylene copolymer and from approximately 0.3% to 5% by weight of a tackifier agent selected from the group consisting of glycerol mono fatty acids, sorbitan mono fatty acids, castor oil and epoxidized soya, said ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of between approximately 8% and 20% and a melt index of between approximately 0.1 and 2 and said polypropylene copolymer being a copolymer of approximately 94% to 99.5% propylene and approximately 0.5% to 6% ethylene and having a refractive index substantially similar to that of the ethylene-vinyl acetate copolymer.
Claim 2
Dependent Claim
127 words
A composition suitable for processing into a stretch wrap film comprising from approximately 79% to 98% by weight of a high molecular weight ethylene-vinyl acetate copolymer, from approximately 1% to 18% by weight of a polypropylene copolymer and from approximately 0.3% to 5% by weight of a tackifier agent selected from the group consisting of glycerol mono fatty acids, sorbitan mono fatty acids, castor oil and epoxidized soya, said ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of between approximately 8% and 20% and a melt index of between approximately 0.1 and 2 and said polypropylene copolymer being a copolymer of approximately 94% to 99.5% propylene and approximately 0.5% to 6% ethylene and having a refractive index substantially similar to that of the ethylene-vinyl acetate copolymer.
Claim 3
Dependent Claim
23 words
A composition as set forth in claim 1 wherein the high molecular weight ethylene-vinyl acetate copolymer has a melt index of approximately 0.25.
Claim 4
Dependent Claim
24 words
A composition as set forth in claim 1 wherein the tackifier agent is present in an amount between approximately 1% and 3% by weight.
Claim 5
Dependent Claim
24 words
A composition as set forth in claim 1 wherein the glycerol mono fatty acid is glycerol monooleate, glycerol monostearate, glycerol monolaurate or glycerol monopalmitate.
Claim 6
Dependent Claim
17 words
A composition as set forth in claim 4 wherein the glycerol mono fatty acid is glycerol monooleate.
Claim 7
Dependent Claim
22 words
A composition as set forth in claim 5 wherein the glycerol monooleate is present in an amount of approximately 2% by weight.
Claim 8
Dependent Claim
22 words
A composition as set forth in claim 1 wherein the ethylene-vinyl acetate copolymer has a vinyl acetate comonomer content of approximately 12%.
Claim 9
Dependent Claim
23 words
A composition as set forth in claim 1 wherein the ethylene-vinyl acetate copolymer is present in an amount of approximately 90% by weight.
Claim 10
Dependent Claim
22 words
A composition as set forth in claim 1 wherein the polypropylene copolymer is present in an amount of approximately 8% by weight.
Claim 11
Dependent Claim
32 words
A composition as set forth in claim 1 wherein the tackifier agent is selected from the group consisting of glycerol monostearate, glycerol monooleate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and sorbitan monooleate.
Claim 12
Dependent Claim
68 words
A composition suitable for processing into a stretch wrap film comprising approximately 90% by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of approximately 12% and a melt index of between approximately 0.1 and 2, approximately 8% by weight of a polypropylene copolymer and of approximately 94% to 99.5% propylene and approximately 0.5% to 6% ethylene and approximately 2% by weight of glycerol monooleate.
Claim 13
Dependent Claim
68 words
A composition suitable for processing into a stretch wrap film comprising approximately 90% by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of approximately 12% and a melt index of between approximately 0.1 and 2, approximately 8% by weight of a polypropylene copolymer and of approximately 94% to 99.5% propylene and approximately 0.5% to 6% ethylene and approximately 2% by weight of glycerol monooleate.
Claim 14
Dependent Claim
123 words
A film prepared from a composition comprising from approximately 79% to 98% by weight of a high molecular weight ethylene-vinyl acetate copolymer, from approximately 1% to 18% by weight of a polypropylene copolymer and from approximately 0.3% to 5% by weight of a tackifier agent selected from the group consisting of glycerol mono fatty acids, sorbitan mono fatty acids, castor oil and epoxidized soya, said ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of between approximately 8% and 20% and a melt index of between approximately 0.1 and 2 and said polypropylene copolymer being a copolymer of approximately 94% to 95% propylene and approximately 0.5% to 6% ethylene and having a refractive index substantially similar to that of the ethylene-vinyl acetate copolymer.
Claim 15
Dependent Claim
123 words
A film prepared from a composition comprising from approximately 79% to 98% by weight of a high molecular weight ethylene-vinyl acetate copolymer, from approximately 1% to 18% by weight of a polypropylene copolymer and from approximately 0.3% to 5% by weight of a tackifier agent selected from the group consisting of glycerol mono fatty acids, sorbitan mono fatty acids, castor oil and epoxidized soya, said ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of between approximately 8% and 20% and a melt index of between approximately 0.1 and 2 and said polypropylene copolymer being a copolymer of approximately 94% to 95% propylene and approximately 0.5% to 6% ethylene and having a refractive index substantially similar to that of the ethylene-vinyl acetate copolymer.
Claim 16
Dependent Claim
21 words
A film according to claim 12 wherein the high molecular weight ethylene-vinyl acetate copolymer has a melt index of approximately 0.25.
Claim 17
Dependent Claim
22 words
A film according to claim 12 wherein the tackifier agent is present in an amount between approximately 1% and 3% by weight.
Claim 18
Dependent Claim
22 words
A film according to claim 12 wherein the glycerol mono fatty acid is glycerol monooleate, glycerol monostearate, glycerol monolaurate or glycerol monopalmitate.
Claim 19
Dependent Claim
15 words
A film according to claim 15 wherein the glycerol mono fatty acid is glycerol monooleate.
Claim 20
Dependent Claim
20 words
A film according to claim 16 wherein the glycerol monooleate is present in an amount of approximately 2% by weight.
Claim 21
Dependent Claim
20 words
A film according to claim 12 wherein the ethylene-vinyl acetate copolymer has a vinyl acetate comonomer content of approximately 12%.
Claim 22
Dependent Claim
22 words
A film prepared according to claim 12 wherein the ethylene-vinyl acetate copolymer is present in an amount of approximately 90% by weight.
Claim 23
Dependent Claim
21 words
A film prepared according to claim 12 wherein the polypropylene copolymer is present in an amount of approximately 8% by weight.
Claim 24
Dependent Claim
31 words
A film prepared according to claim 12 wherein the tackifier agent is selected from the group consisting of glycerol monostearate, glycerol monooleate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate and sorbitan monooleate.
Claim 25
Dependent Claim
63 words
A film prepared from a composition comprising approximately 90% by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of approximately 12% and a melt index of between approximately 0.1 and 2, approximately 8% by weight of a polypropylene copolymer of approximately 94% to 99.5% propylene and approximately 0.5% to 6% ethylene and approximately 2% by weight of glycerol monooleate.
Claim 26
Dependent Claim
63 words
A film prepared from a composition comprising approximately 90% by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate comonomer content of approximately 12% and a melt index of between approximately 0.1 and 2, approximately 8% by weight of a polypropylene copolymer of approximately 94% to 99.5% propylene and approximately 0.5% to 6% ethylene and approximately 2% by weight of glycerol monooleate.
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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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |