US4746562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Packaging film
Assignee: WRGRACE & Co A CORP OF CONNECTICUT
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Filing: 1986-02-28
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Granted: 1988-05-24
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Expires: 2006-02-28
Abstract
Abstract A multilayer film useful in the packaging of high acid food products at elevated temperatures comprises a core layer of ethylene vinyl alcohol copolymer, two intermediate layers each comprising a polyamide; outer blend layers of linear low density polyethylene and anti-blocking agent, and adhesive polymeric materials to adhere the outer blend layers to the respective intermediate polyamide layers.
Inventors
- 👤 Ennis M. Fant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:42
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29C; B29C48/00; B29C48/16; B29C48/18; B29C48/185; B29C48/03; B29C48/07; B29C48/08; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1334; Y10T428/1341; Y10T428/1352; Y10T428/1379; Y10T428/1383; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/26; Y10T428/269; Y10T428/31504; Y10T428/31725; Y10T428/31739; Y10T428/31743; Y10T428/31746; Y10T428/3175; Y10T428/31757; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
70 words
A multilayer coextruded film comprising: (a) a core layer comprising an ethylene vinyl alcohol copolymer; (b) two intermediate layers each comprising a polyamide; (c) two outer layers each comprising a blend of from about 85% to about 99% of a linear low density polyethylene and from about 1% to about 15% of an anti-blocking agent; and (d) two layers of adhesive polymeric material disposed between respective intermediate and outer layers.
Claim 2
Dependent Claim
70 words
A multilayer coextruded film comprising: (a) a core layer comprising an ethylene vinyl alcohol copolymer; (b) two intermediate layers each comprising a polyamide; (c) two outer layers each comprising a blend of from about 85% to about 99% of a linear low density polyethylene and from about 1% to about 15% of an anti-blocking agent; and (d) two layers of adhesive polymeric material disposed between respective intermediate and outer layers.
Claim 3
Dependent Claim
38 words
The film of claim 1 wherein each of said outer layers comprises a blend of from about 90% to about 95% of said linear low density polyethylene, and from about 5% to about 10% of said anti-blocking agent.
Claim 4
Dependent Claim
30 words
The film of claim 1 wherein each of said outer layers comprises a blend of about 90% of said linear low density polyethylene, and about 10% of said anti-blocking agent.
Claim 5
Dependent Claim
26 words
The film of claim 1 wherein said core layer comprises an ethylene vinyl alcohol copolymer with an ethylene content of from about 20% to about 40%.
Claim 6
Dependent Claim
26 words
The film of claim 1 where said core layer comprises an ethylene vinyl alcohol copolymer with an ethylene content of from about 25% to about 35%.
Claim 7
Dependent Claim
22 words
The film of claim 1 wherein said core layer comprises an ethylene vinyl alcohol copolymer with an ethylene content of about 32%.
Claim 8
Dependent Claim
11 words
The film of claim 1 wherein said polyamide is nylon 6.
Claim 9
Dependent Claim
11 words
The film of claim 1 wherein said anti-blocking agent is silica.
Claim 10
Dependent Claim
73 words
The film of claim 1 wherein: (a) the thickness of the core layer comprises about 10% of the total film thickness; (b) the thickness of the two intermediate layers together comprises about 22% of the total film thickness; (c) the thickness of the two outer layers together comprises about 52% of the total film thickness; and (d) the thickness of the two adhesive layers together comprises about 16% of the total film thickness.
Claim 11
Dependent Claim
15 words
The film according to claim 9 wherein the total film thickness is about 5 mils.
Claim 12
Dependent Claim
76 words
A seven-layer coextruded film comprising: (a) a core layer comprising an ethylene vinyl alcohol copolymer; (b) two intermediate layers each comprising a polyamide; (c) two outer layers each comprising a blend of from about 85% to about 99% of a linear low density polyethylene, and from about 1% to about 15% of an anti-blocking agent; and (d) each of said intermediate layers adhered to a respective surface layer by an acid- or acid anhydride-modified polymeric adhesive.
Claim 13
Dependent Claim
76 words
A seven-layer coextruded film comprising: (a) a core layer comprising an ethylene vinyl alcohol copolymer; (b) two intermediate layers each comprising a polyamide; (c) two outer layers each comprising a blend of from about 85% to about 99% of a linear low density polyethylene, and from about 1% to about 15% of an anti-blocking agent; and (d) each of said intermediate layers adhered to a respective surface layer by an acid- or acid anhydride-modified polymeric adhesive.
Claim 14
Dependent Claim
83 words
A seven-layer coextruded film suitable for use in packaging food products comprising: (a) a core layer comprising an ethylene vinyl alcohol copolymer; (b) two intermediate layers each comprising a polyamide; (c) two outer layers each comprising a blend of from about 90% to about 95% of a linear low density polyethylene, and from about 5% to about 10% of an anti-blocking agent; and (d) each of said intermediate layers adhered to a respective surface layer by an acid- or acid anhydride-modified polymeric adhesive.
Claim 15
Dependent Claim
83 words
A seven-layer coextruded film suitable for use in packaging food products comprising: (a) a core layer comprising an ethylene vinyl alcohol copolymer; (b) two intermediate layers each comprising a polyamide; (c) two outer layers each comprising a blend of from about 90% to about 95% of a linear low density polyethylene, and from about 5% to about 10% of an anti-blocking agent; and (d) each of said intermediate layers adhered to a respective surface layer by an acid- or acid anhydride-modified polymeric adhesive.
Claim 16
Dependent Claim
36 words
The coextruded film according to claim 1 wherein a layer comprising a blend of linear low density polyethylene and an anti-blocking agent is disposed between each respective layer of adhesive polymeric material and an outer layer.
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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) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |