US4296156A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer film including a polyurethane
Assignee: Viskase Corp
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Filing: 1979-12-26
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Granted: 1981-10-20
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Expires: 1999-12-26
Abstract
Abstract A flexible biaxially oriented multilayer film includes at least one layer having a thickness of at least about 0.5 mil and consisting essentially of an aromatic polyurethane, the film having been subjected to a biaxial stretching in the range of from about 12 to about 18, preferably about 16.
Inventors
- 👤 Stanley Lustig
- 👤 Stephen J. Vicik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:59
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/40; B32B27/06; B32B27/08; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/50; B32B2307/514; B32B2307/518; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/7244; B32B2439/00; B32B2439/70; Y; Y10; Y10S; Y10S383/00; Y10S383/908; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/13; Y10T428/1334; Y10T428/1341; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/266; Y10T428/31504; Y10T428/31551; Y10T428/31554; Y10T428/31573; Y10T428/3158; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192; Y10T428/31928; Y10T428/31935
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
61 words
A flexible puncture resistant biaxially oriented coextruded multilayer film having a thickness of from about 2.0 to about 3.5 mils comprising at least one layer having a thickness of at least about 0.5 mil and consisting essentially of an aromatic polyurethane elastomer, said film having been subjected to a biaxial stretching in the range of from about 12 to about 18.
Claim 2
Dependent Claim
61 words
A flexible puncture resistant biaxially oriented coextruded multilayer film having a thickness of from about 2.0 to about 3.5 mils comprising at least one layer having a thickness of at least about 0.5 mil and consisting essentially of an aromatic polyurethane elastomer, said film having been subjected to a biaxial stretching in the range of from about 12 to about 18.
Claim 3
Dependent Claim
13 words
The multilayer film of claim 1, wherein the biaxial stretching is about 16.
Claim 4
Dependent Claim
39 words
The multilayer film of claim 1, wherein said aromatic polyurethane has a melt flow of from about 0.5 to about 12 decigrams per minute at 190° C. and a Shore hardness A of from about 70 to about 100.
Claim 5
Dependent Claim
29 words
The multilayer film of claim 1, wherein said aromatic polyurethane has a melt flow less than about 4.0 decigrams per minute and a Shore hardness A of about 80.
Claim 6
Dependent Claim
16 words
The multilayer film of claim 1, wherein said film has a thickness of about 2.75 mils.
Claim 7
Dependent Claim
11 words
A primal meat bag formed from the film of claim 1.
Claim 8
Dependent Claim
71 words
The multilayer film of claim 1, wherein said film has a first outer layer of a heat sealable polymer; a first core layer connected to said first outer layer and serving as an oxygen barrier; a second core layer of said aromatic polyurethane connected to said first core layer; and a second outer layer connected to said second core layer of a biaxially orientable polymer which adheres to said aromatic polyurethane.
Claim 9
Dependent Claim
39 words
The multilayer film of claim 7, wherein said aromatic polyurethane has a melt flow of from about 0.5 to about 12 decigrams per minute at 190° C. and a Shore hardness A of from about 70 to about 100.
Claim 10
Dependent Claim
11 words
A primal meat bag formed from the film of claim 7.
Claim 11
Dependent Claim
165 words
A flexible puncture resistant biaxially oriented coextruded multilayer film having a thickness of from about 2.0 to about 3.5 mils, comprising: a first outer layer of ethylene vinyl acetate copolymer having a vinyl acetate content of from about 5% to about 18% by weight and having a melt flow of from about 0.2 to about 1.0 decigram per minute; a first core layer of polyvinylidene chloride copolymer having at least about 50% by weight of a polymerized vinylidene chloride and containing a maximum of about 5% by weight of a plasticizer; a second core layer of aromatic polyurethane elastomer having a thickness of at least about 0.5 mil; and a second outer layer of ethylene vinyl acetate copolymer having a vinyl acetate content of from about 5% to about 18% by weight and a melt flow of from about 0.2 to about 1.0 decigrams per minute; said film having been subjected to a biaxial stretching in the range of from about 12 to about 18.
Claim 12
Dependent Claim
165 words
A flexible puncture resistant biaxially oriented coextruded multilayer film having a thickness of from about 2.0 to about 3.5 mils, comprising: a first outer layer of ethylene vinyl acetate copolymer having a vinyl acetate content of from about 5% to about 18% by weight and having a melt flow of from about 0.2 to about 1.0 decigram per minute; a first core layer of polyvinylidene chloride copolymer having at least about 50% by weight of a polymerized vinylidene chloride and containing a maximum of about 5% by weight of a plasticizer; a second core layer of aromatic polyurethane elastomer having a thickness of at least about 0.5 mil; and a second outer layer of ethylene vinyl acetate copolymer having a vinyl acetate content of from about 5% to about 18% by weight and a melt flow of from about 0.2 to about 1.0 decigrams per minute; said film having been subjected to a biaxial stretching in the range of from about 12 to about 18.
Claim 13
Dependent Claim
32 words
The multilayer film of claim 10, wherein the balance of said polyvinylidene chloride copolymer in said first core layer is selected from the group consisting of vinyl chloride, acrylonitrile and acrylate ester.
Claim 14
Dependent Claim
37 words
The multilayer film of claim 10, wherein said first core layer comprises from about 70% to about 90% by weight of a polymerized vinylidene chloride and from about 2% to about 5% by weight of a plasticizer.
Claim 15
Dependent Claim
22 words
The multilayer film of claim 12, wherein said plasticizer is selected from the group consisting of dibutyl sebacate and epoxidized soybean oil.
Claim 16
Dependent Claim
43 words
The multilayer film of claim 10, wherein said aromatic polyurethane elastomer is said second core layer has a melt flow of less than about 4.0 decigrams per minute at 190° C. and a Shore hardness A of from about 70 to about 100.
Claim 17
Dependent Claim
14 words
The multilayer film of claim 14, wherein said Shore hardness A is about 80.
Claim 18
Dependent Claim
16 words
The multilayer film of claim 10, wherein said film has a thickness of about 2.75 mils.
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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) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |