Patent US4064296A successfully refreshed from Google Patents.
US4064296A
Expired / Lapsed
US
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Heat shrinkable multi-layer film of hydrolyzed ethylene vinyl acetate and a cross-linked olefin polymer
Assignee: WR Grace and Co Conn
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Filing: 1975-10-02
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Granted: 1977-12-20
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Expires: 1995-10-02
Abstract
Abstract A heat shrinkable multi-layer packaging film having a layer of a hydrolyzed ethylene-vinyl acetate copolymer. Preferably, the film is formed by coextruding the hydrolyzed ethylene-vinyl acetate copolymer layer between two other polymeric layers, at least one of which is cross-linkable, and thereafter irradiating and orienting the multi-layer structure. The resulting film is heat shrinkable and has very low oxygen permeability.
Inventors
- 👤 Norman D. Bornstein
- 👤 Donald J. D'Entremont
- 👤 Alan S. Weinberg
- 👤 Henry G. Schirmer
- 👤 Joseph Zu Sun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:41
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/28; B32B27/30; B32B27/306; B32B27/32; B65; B65D; B65D65/00; B65D65/38; B32B2307/00; B32B2307/50; B32B2307/514; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/7244; B32B2307/732; B32B2307/734; B32B2307/736; B32B2439/00; B32B2553/00; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928; Y10T428/31935
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
81 words
A multi-layer packaging film having low oxygen permeability comprising: a. two polymeric layers, at least one of which comprises an olefin polymer cross-linked to the equivalent of a dosage level in the range of 2 to 12 MR; and, b. a layer between said two polymeric layers which comprises a hydrolyzed ethylenevinyl acetate copolymer thereby defining a multi-layer film having at least three layers, said film having at least 10% heat shrinkage in both longitudinal and transverse directions at 195° F.
Claim 2
Dependent Claim
81 words
A multi-layer packaging film having low oxygen permeability comprising: a. two polymeric layers, at least one of which comprises an olefin polymer cross-linked to the equivalent of a dosage level in the range of 2 to 12 MR; and, b. a layer between said two polymeric layers which comprises a hydrolyzed ethylenevinyl acetate copolymer thereby defining a multi-layer film having at least three layers, said film having at least 10% heat shrinkage in both longitudinal and transverse directions at 195° F.
Claim 3
Dependent Claim
29 words
The film of claim 1 wherein both of said two polymeric layers are cross-linked to the equivalent of a dosage level in the range of 2 to 12 MR.
Claim 4
Dependent Claim
16 words
The film of claim 1 wherein said two polymeric layers each comprise an ethylene-vinyl acetate copolymer.
Claim 5
Dependent Claim
13 words
The film of claim 1 wherein said two polymeric layers each comprise polyethylene.
Claim 6
Dependent Claim
26 words
The film of claim 1 wherein said laminate has an oxygen transmission rate of less than 2.0 cc/m 2 , 24 hrs., atm. at 73° F.
Claim 7
Dependent Claim
15 words
The film of claim 1 wherein said copolymer is hydrolyzed to at least 50% .
Claim 8
Dependent Claim
18 words
The film of claim 1 wherein said copolymer has 35 to 85 mole percent of vinyl acetate units.
Claim 9
Dependent Claim
27 words
The film of claim 1 wherein said film has a minimum free heat shrinkage of about 10% at 195° F in both the transverse and longitudinal directions.
Claim 10
Dependent Claim
23 words
The film of claim 1 having an oxygen transmission rate of less than 30.0 cc/m 2 , 24 hrs., atm. at 73° F.
Claim 11
Dependent Claim
10 words
The film of claim 1 wherein said film is tubular.
Claim 12
Dependent Claim
24 words
The tubular film of claim 10 wherein said tube is heat sealed at one end to close same thereby forming a heat shrinkable bag.
Claim 13
Dependent Claim
45 words
A heat shrinkable multi-layer film having at least one layer which comprises a hydrolyzed ethylene vinyl acetate copolymer and a layer of crosslinked olefin polymer, said film having an oxygen transmission rate of less than 30.0 cc/m 2 , 24 hrs., atm. at 73° F.
Claim 14
Dependent Claim
45 words
A heat shrinkable multi-layer film having at least one layer which comprises a hydrolyzed ethylene vinyl acetate copolymer and a layer of crosslinked olefin polymer, said film having an oxygen transmission rate of less than 30.0 cc/m 2 , 24 hrs., atm. at 73° F.
Claim 15
Dependent Claim
14 words
The film of claim 12 wherein said olefin polymer layer comprises ethylene-vinyl acetate copolymer.
Claim 16
Dependent Claim
12 words
The film of claim 12 wherein said olefin polymer layer comprises polyethylene.
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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) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |