Patent US4839235A successfully refreshed from Google Patents.
US4839235A
Expired / Lapsed
US
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Oxygen barrier film
Assignee: Cryovac LLC
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Filing: 1987-09-28
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Granted: 1989-06-13
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Expires: 2007-09-28
Abstract
Abstract A coextruded multiple layer oriented film comprises a core layer comprising an ethylene vinyl alcohol copolymer, two intermediate adhesive layers, and two outer layers comprising a polymeric material selected from the group consisting of ethylene butyl acrylate copolymer, and blends comprising at least 10% of said ethylene butyl acrylate copolymer blended with ethylene alpha-olefin copolymers. A preferred embodiment of the multilayer film exhibits high oxygen barrier especially useful in food packaging applications.
Inventors
- 👤 Gautam P. Shah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:10
CPC Classifications
C; C09; C09D; C09D123/00; C09D123/02; C09D123/04; C09D123/08; B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; C09D123/0807; C09D123/0815; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31725; Y10T428/31739; Y10T428/31743; Y10T428/31746; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
An oriented multilayer film comprising: (a) a cross-linked core layer comprising an ethylene vinyl alcohol copolymer; (b) two cross-linked interior layers, each layer bonded to a respective surface of the core layer and comprising a copolymer or terpolymer having a polyolefin or ethylene-ester copolymer component modified with an unsaturated carboxylic acid or acid anhydride; and (c) two cross-linked outer layers each consisting essentially of a blend of between about 10% and 50% ethylene butyl, acrylate copolymer, between about 25% and 50% linear low density polyethylene having a density in a range of from about 0.916 grams per cubic centimeter to about 0.925 grams per cubic centimeter, and between about 25% and 40% linear medium density polyethylene having a density in a range of from about 0.926 grams per cubic centimeter to about 0.941 grams per cubic centimeter.
Claim 2
Dependent Claim
137 words
An oriented multilayer film comprising: (a) a cross-linked core layer comprising an ethylene vinyl alcohol copolymer; (b) two cross-linked interior layers, each layer bonded to a respective surface of the core layer and comprising a copolymer or terpolymer having a polyolefin or ethylene-ester copolymer component modified with an unsaturated carboxylic acid or acid anhydride; and (c) two cross-linked outer layers each consisting essentially of a blend of between about 10% and 50% ethylene butyl, acrylate copolymer, between about 25% and 50% linear low density polyethylene having a density in a range of from about 0.916 grams per cubic centimeter to about 0.925 grams per cubic centimeter, and between about 25% and 40% linear medium density polyethylene having a density in a range of from about 0.926 grams per cubic centimeter to about 0.941 grams per cubic centimeter.
Claim 3
Dependent Claim
27 words
The film of claim 1 wherein said ethylene butyl acrylate copolymer comprises from about 0.5%, by weight, to about 19%, by weight of butyl acrylate derived units.
Claim 4
Dependent Claim
21 words
The film of claim 1 wherein said ethylene butyl acrylate copolymer comprises about 2.5%, by weight, of butyl acrylate derived units.
Claim 5
Dependent Claim
20 words
The film of claim 1 which has been cross-linked with from about three megarads to about thirteen megarads of irradiation.
Claim 6
Dependent Claim
15 words
The film of claim 1 which has been cross-linked with about three megarads of irradiation.
Claim 7
Dependent Claim
29 words
The film of claim 1 which has been oriented by racking at a racking ratio of from about 3.0 to about 5.0 in both the longitudinal and transverse directions.
Claim 8
Dependent Claim
25 words
The film of claim 1 which has been oriented by racking at a racking ratio of about 3.5 in both the longitudinal and transverse directions.
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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) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |