US4359495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retort-sterilizable pouch
Assignee: Union Carbide Chemicals and Plastics Technology LLC
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Filing: 1981-02-25
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Granted: 1982-11-16
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Expires: 2001-02-25
Abstract
Abstract In a retort-sterilizable laminated structure comprising an aluminum foil or sheet, a heat-sealable polymer layer, and a heat-resistant resin layer, the heat-sealable layer is the cracked product of the blend of a poly(propylene-ethylene) copolymer and an ethylene-vinyl acetate copolymer. This heat-sealable layer composition has improved flow properties and may be extrusion-coated onto a metal film substrate at high speeds.
Inventors
- 👤 Carl W. Schroeder
- 👤 Joseph R. Webster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:50
CPC Classifications
B; B32; B32B; B32B15/00; B32B15/04; B32B15/08; B32B2323/00; B32B2323/10; B32B2367/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31681; Y10T428/31692; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
166 words
In a retort-sterilizable laminated structure comprising an aluminum foil or sheet, a heat-sealable polymer layer on one surface of said aluminum foil or sheet, and a heat-resistant resin layer formed on the other surface of said aluminum foil or sheet, the improvement wherein said heat-sealable polymer layer is formed from the composition comprising the cracked product of a blend of a polypropylene copolymer and an ethylene-vinyl acetate copolymer wherein: (a) the melt flow of said cracked product is between about 15 and about 65 grams per 10 minutes, condition L; (b) said polypropylene copolymer is a propylene-ethylene copolymer comprising between about 1 and about 10 percent by weight ethylene and has a melt flow of between about 0.5 and about 15 grams per 10 minutes, condition L; and (c) said ethylene-vinyl acetate copolymer has a vinyl acetate content of between about 15 and about 30 percent by weight, and has a melt flow of between about 1 and about 30 grams per 10 minutes, condition E.
Claim 2
Dependent Claim
166 words
In a retort-sterilizable laminated structure comprising an aluminum foil or sheet, a heat-sealable polymer layer on one surface of said aluminum foil or sheet, and a heat-resistant resin layer formed on the other surface of said aluminum foil or sheet, the improvement wherein said heat-sealable polymer layer is formed from the composition comprising the cracked product of a blend of a polypropylene copolymer and an ethylene-vinyl acetate copolymer wherein: (a) the melt flow of said cracked product is between about 15 and about 65 grams per 10 minutes, condition L; (b) said polypropylene copolymer is a propylene-ethylene copolymer comprising between about 1 and about 10 percent by weight ethylene and has a melt flow of between about 0.5 and about 15 grams per 10 minutes, condition L; and (c) said ethylene-vinyl acetate copolymer has a vinyl acetate content of between about 15 and about 30 percent by weight, and has a melt flow of between about 1 and about 30 grams per 10 minutes, condition E.
Claim 3
Dependent Claim
16 words
The structure according to claim 1 wherein said heat-resistant resin layer is formed from a polyester.
Claim 4
Dependent Claim
12 words
The structure according to claim 2 wherein said polyester is poly(ethylene terephthalate).
Claim 5
Dependent Claim
25 words
The structure according to claim 1 wherein the melt flow of said cracked product is between about 10 and about 50 grams per 10 minutes.
Claim 6
Dependent Claim
25 words
The structure according to claim 4 wherein said polypropylene copolymer is a random copolymer comprising between about 1 and about 10 percent by weight ethylene.
Claim 7
Dependent Claim
15 words
The structure according to claim 1 wherein said cracked product is prepared by peroxide cracking.
Claim 8
Dependent Claim
13 words
The structure according to claim 6 wherein said peroxide is an aliphatic peroxide.
Claim 9
Dependent Claim
34 words
The structure according to claim 1 wherein said blend comprises between about 5 and about 25 percent by weight ethylene-vinyl acetate copolymer and between about 95 and about 75 percent by weight polypropylene copolymer.
Claim 10
Dependent Claim
36 words
The structure according to claim 1 wherein said heat-sealable layer is formed on the surface of said aluminum foil or sheet by extrusion coating said cracked product at line speeds above about 400 feet per minute.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |