US4863784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer film containing very low density polyethylene
Assignee: Curwood Inc
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Filing: 1987-05-28
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Granted: 1989-09-05
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Expires: 2007-05-28
Abstract
Abstract A coextruded, heat shrinkable, thermoplastic multilayer film for packaging fresh red meat cuts and processed meats. The film comprises a first layer comprising very low density polyethylene, a first core layer of vinylidene chloride-methyl acrylate copolymer, and a second layer comprising very low density polyethylene. In another embodiment the first layer is a second core layer confined between said first core layer and a first outer layer comprising a heat sealable thermoplastic polymer or copolymer. In a further embodiment the second layer is a second core layer confined between said first core layer and a second outer layer comprising a thermoplastic polymer or copolymer.
Inventors
- 👤 Stanley Lustig
- 👤 Jeffrey M. Schuetz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:26
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/08; B32B1/00; B32B1/08; B32B27/30; B32B27/304; B32B38/00; B32B38/0012; B32B2038/0028; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/70; B32B2307/72; B32B2307/732; B32B2307/734; B32B2307/736; B32B2323/00; B32B2323/04; B32B2323/046; B32B2327/00; B32B2327/06; B32B2439/00; B32B2439/70; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1352; Y10T428/1379; Y10T428/1383; Y10T428/24; Y10T428/24942; Y10T428/24992; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
134 words
A coextruded, thermoplastic, heat shrinkable, multilayer film wherein: (a) said multilayer film comprises a first layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter, a core layer comprising vinylidene chloride-methyl acrylate copolymer having a vinylidene chloride content of from about 85 to about 95 weight percent and a methyl acrylate content of from about 5 to about 15 weight percent all based on the weight of said copolymer, and a second layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter; and, (b) said first layer is adhered directly to one side of said core layer without adhesive material therebetween and said second layer is adhered directly to the other side of said core layer without adhesive material therebetween.
Claim 2
Dependent Claim
134 words
A coextruded, thermoplastic, heat shrinkable, multilayer film wherein: (a) said multilayer film comprises a first layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter, a core layer comprising vinylidene chloride-methyl acrylate copolymer having a vinylidene chloride content of from about 85 to about 95 weight percent and a methyl acrylate content of from about 5 to about 15 weight percent all based on the weight of said copolymer, and a second layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter; and, (b) said first layer is adhered directly to one side of said core layer without adhesive material therebetween and said second layer is adhered directly to the other side of said core layer without adhesive material therebetween.
Claim 3
Dependent Claim
17 words
A multilayer film according to claim 1 wherein said first layer and said second layer are identical.
Claim 4
Dependent Claim
25 words
A multilayer film according to claim 2 wherein said density is in the range of from about 0.86 to about 0.915 grams per cubic centimeter.
Claim 5
Dependent Claim
44 words
A multilayer film according to claim 1 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer have a melt index in the range of from about 0.5 to about 2.5 decigrams per minute.
Claim 6
Dependent Claim
47 words
A multilayer film according to claim 1 wherein said very low density poylethylene of said first layer and said very low density polyethylene of said second layer have a density of about 0.912 grams per cubic centimeter and a melt index of about 1.0 decigrams per minute.
Claim 7
Dependent Claim
33 words
A multilayer film according to claim 1 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer are copolymers of ethylene and octene-1.
Claim 8
Dependent Claim
22 words
A multilayer film according to claim 1 wherein said core layer comprises vinylidene chloride-methyl acrylate copolymer blended with vinylidene chloride-vinyl chloride copolymer.
Claim 9
Dependent Claim
28 words
A multilayer film according to claim 7 wherein said blend comprises about 75 weight percent vinylidene chloride-methyl acrylate copolymer and about 25 weight percent vinylidene chloride-vinyl chloride copolymer.
Claim 10
Dependent Claim
37 words
A multilayer film according to claim 1 wherein said first layer is a second core layer confined between said first core layer of vinylidene chloride-methyl acrylate copolymer and first outer layer comprising a heat sealable thermoplastic polymer.
Claim 11
Dependent Claim
41 words
A multilayer film according to claim 9 wherein said first outer layer comprises a heat sealable thermoplastic polymer selected from the group consisting of an ionomer, an ethylene vinyl acetate copolymer, and ethylene-propylene copolymer, and a polypropylene blended with another polymer.
Claim 12
Dependent Claim
36 words
A multilayer film according to claim 1 wherein said second layer is a second core layer confined between said first core layer of vinylidene chloride-methyl acrylate copolymer and a second outer layer comprising a thermoplastic polymer.
Claim 13
Dependent Claim
29 words
A multilayer film according to claim 11 wherein said second outer layer comprises a blend of high density polyethylene with linear low density polyethylene or very low density polyethylene.
Claim 14
Dependent Claim
28 words
A multilayer film according to claim 12 wherein the amount of high density polyethylene in said blend is not greater than about 30 weight percent of the blend.
Claim 15
Dependent Claim
13 words
A multilayer film according to claim 1 wherein said film contains cross-linking bonds.
Claim 16
Dependent Claim
16 words
A multilayer film according to claim 14 wherein said film has been cross-linked by chemical means.
Claim 17
Dependent Claim
15 words
A multilayer film according to claim 14 wherein said film has been cross-linked by irradiation.
Claim 18
Dependent Claim
25 words
A multilayer film according to claim 16 wherein said film has been irradiated to a dosage level of from about 1 to about 5 megarads.
Claim 19
Dependent Claim
17 words
A multilayer film according to claim 14 wherein said first layer and said second layer are identical.
Claim 20
Dependent Claim
25 words
A multilayer film according to claim 18 wherein said density is in the range of from about 0.86 to about 0.915 grams per cubic centimeter.
Claim 21
Dependent Claim
44 words
A multilayer film according to claim 14 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer have a melt index in the range of from about 0.5 to about 2.5 decigrams per minute.
Claim 22
Dependent Claim
47 words
A multilayer film according to claim 14 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer have a density of about 0.912 grams per cubic centimeter and a melt index of about 1.0 decigrams per minute.
Claim 23
Dependent Claim
33 words
A multilayer film according to claim 14 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer are copolymers of ethylene and octene-1.
Claim 24
Dependent Claim
22 words
A multilayer film according to claim 14 wherein said core layer comprises vinylidene chloride-methyl acrylate copolymer blended with vinylidene chloride-vinyl chloride copolymer.
Claim 25
Dependent Claim
28 words
A multilayer film according to claim 23 wherein said blend comprises about 75 weight percent vinylidene chloride-methyl acrylate copolymer and about 25 weight percent vinylidene chloride-vinyl chloride copolymer.
Claim 26
Dependent Claim
38 words
A multilayer film according to claim 14 wherein said first layer is a second core layer confined between said first core layer of vinylidene chloride-methyl acrylate copolymer and a first outer layer comprising a heat sealable thermoplastic polymer.
Claim 27
Dependent Claim
41 words
A multilayer film according to claim 25 wherein said first outer layer comprises a heat sealable thermoplastic polymer selected from the group consisting of an ionomer, an ethylene vinyl acetate copolymer, an ethylene-propylene copolymer, and a propylene blended with another polymer.
Claim 28
Dependent Claim
36 words
A multilayer film according to claim 14 wherein said second layer is a second core layer confined between said first core layer of vinylidene chloride-methyl acrylate copolymer and a second outer layer comprising a thermoplastic polymer.
Claim 29
Dependent Claim
29 words
A multilayer film according to claim 27 wherein said second outer layer comprises a blend of high density polyethylene with linear low density polyethylene or very low density polyethylene.
Claim 30
Dependent Claim
28 words
A multilayer film according to claim 28 wherein the amount of high density polyethylene in said blend is not greater than about 30 weight percent of the blend.
Claim 31
Dependent Claim
23 words
A multilayer film according to any one of claims 1 through 20 wherein said multilayer film is in the form of a bag.
Claim 32
Dependent Claim
148 words
A coextruded, thermoplastic, heat shrinkable, multilayer film wherein: (a) said multilayer film comprises a first layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter, a core layer comprising vinylidene chloride-methyl acrylate copolymer having a vinylidene chloride content of from about 85 to about 95 weight percent and a methyl acrylate content of from about 5 to about 15 weight percent all based on the weight of said copolymer, and a second layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter; (b) said first layer is adhered directly to one side of said core layer without adhesive material therebetween and said second layer is adhered directly to the other side of said core layer without adhesive material therebetween; and (c) said first layer and said second layer have substantial freedom from cross-linking bonds.
Claim 33
Dependent Claim
148 words
A coextruded, thermoplastic, heat shrinkable, multilayer film wherein: (a) said multilayer film comprises a first layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter, a core layer comprising vinylidene chloride-methyl acrylate copolymer having a vinylidene chloride content of from about 85 to about 95 weight percent and a methyl acrylate content of from about 5 to about 15 weight percent all based on the weight of said copolymer, and a second layer comprising very low density polyethylene of density not greater than about 0.915 grams per cubic centimeter; (b) said first layer is adhered directly to one side of said core layer without adhesive material therebetween and said second layer is adhered directly to the other side of said core layer without adhesive material therebetween; and (c) said first layer and said second layer have substantial freedom from cross-linking bonds.
Claim 34
Dependent Claim
17 words
A multilayer film according to claim 31 wherein said first layer and said second layer are identical.
Claim 35
Dependent Claim
25 words
A multilayer film according to claim 32 wherein said density is in the range of from about 0.86 to about 0.915 grams per cubic centimeter.
Claim 36
Dependent Claim
44 words
A multilayer film according to claim 31 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer have a melt index in the range of from about 0.5 to about 2.5 decigrams per minute.
Claim 37
Dependent Claim
47 words
A multilayer film according to claim 31 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer have a density of about 0.912 grams per cubic centimeter and a melt index of about 1.0 decigrams per minute.
Claim 38
Dependent Claim
33 words
A multilayer film according to claim 31 wherein said very low density polyethylene of said first layer and said very low density polyethylene of said second layer are copolymers or ethylene and octene-1.
Claim 39
Dependent Claim
22 words
A multilayer film according to claim 31 wherein said core layer comprises vinylidene chloride-methyl acrylate copolymer blended with vinylidene chloride-vinyl chloride copolymer.
Claim 40
Dependent Claim
28 words
A multilayer film according to claim 37 wherein said blend comprises about 75 weight percent vinylidene chloride-methyl acrylate copolymer and about 25 weight percent vinylidene chloride-vinyl chloride copolymer.
Claim 41
Dependent Claim
38 words
A multilayer film according to claim 31 wherein said first layer is a second core layer confined between said first core layer of vinylidene chloride-methyl acrylate copolymer and a first outer layer comprising a heat sealable thermoplastic polymer.
Claim 42
Dependent Claim
41 words
A multiplayer film according to claim 39 wherein said first outer layer comprises a heat sealable thermoplastic polymer selected from the group consisting of an ionomer, an ethylene vinyl acetate copolymer, an ethylene-propylene copolymer, and a propylene blended with another polymer.
Claim 43
Dependent Claim
36 words
A multilayer film according to claim 31 wherein said second layer is a second core layer confined between said first core layer of vinylidene chloride-methyl acrylate copolymer and a second outer layer comprising a thermoplastic polymer.
Claim 44
Dependent Claim
29 words
A multilayer film according to claim 41 wherein said second outer layer comprises a blend of high density polyethylene with linear low density polyethylene or very low density polyethylene.
Claim 45
Dependent Claim
28 words
A multilayer film according to claim 42 wherein the amount of high density polyethylene in said blend is not greater than about 30 weight percent of the blend.
Claim 46
Dependent Claim
23 words
A multilayer film according to any one of claims 31 through 43 wherein said multilayer film is in the form of a bag.
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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) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |