Patent US4608302A successfully refreshed from Google Patents.
US4608302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oriented films from propylene copolymers and unplasticized saran
Assignee: Cryovac LLC
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Filing: 1985-01-30
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Granted: 1986-08-26
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Expires: 2005-01-30
Abstract
Abstract A heat-shrinkable thermoplastic film includes a food contact layer; a second layer of propylene homopolymer or copolymer, ethylene copolymer, butylene homopolymer or blends thereof; an adhesive layer; a layer of unplasticized vinylidene chloride copolymer; another adhesive layer; and an optical clarity layer.
Inventors
- 👤 Henry G. Schirmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:51
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10; B29C48/16; B29C48/18; B29C48/185; B32B27/30; B32B27/304; B32B7/00; B32B7/04; B32B7/12; B32B2307/00; B32B2307/30; B32B2307/31; B32B2307/40; B32B2307/412; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/726; B32B2307/7265; B32B2307/732; B32B2307/734; B32B2307/736; B32B2439/00; B32B2439/70; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10S428/913; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
91 words
A heat-shrinkable thermoplastic film suitable for the packaging of food products comprising: (a) a first, heat-sealable food contact layer comprising propylene homopolymer or copolymer; (b) a second layer taken from the group consisting of propylene homopolymer, propylene copolymer, ethylene copolymer, butylene homopolymer, or blends thereof; (c) a third or adhesive layer comprising a copolymer of ethylene; (d) a fourth or barrier layer comprising a low viscosity unplasticized vinylidene chloride copolymer; (e) a fifth or adhesive layer; and (f) a sixth or optical clarity layer as in said first or second layer.
Claim 2
Dependent Claim
91 words
A heat-shrinkable thermoplastic film suitable for the packaging of food products comprising: (a) a first, heat-sealable food contact layer comprising propylene homopolymer or copolymer; (b) a second layer taken from the group consisting of propylene homopolymer, propylene copolymer, ethylene copolymer, butylene homopolymer, or blends thereof; (c) a third or adhesive layer comprising a copolymer of ethylene; (d) a fourth or barrier layer comprising a low viscosity unplasticized vinylidene chloride copolymer; (e) a fifth or adhesive layer; and (f) a sixth or optical clarity layer as in said first or second layer.
Claim 3
Dependent Claim
25 words
The film of claim 1 wherein said first layer comprises a propylene-ethylene copolymer, the ethylene content being minor in extent and sufficient to promote orientability.
Claim 4
Dependent Claim
20 words
The film of claim 1 wherein said second layer comprises a propylene homopolymer or copolymer as in said first layer.
Claim 5
Dependent Claim
12 words
The film of claim 1 wherein said second layer comprises ethylene copolymer.
Claim 6
Dependent Claim
25 words
The film of claim 4 wherein an ethylene copolymer has a vinyl acetate content of between about 10 and 12% and a fractional melt index.
Claim 7
Dependent Claim
13 words
The film of claim 1 wherein said third layer comprises ethylene methacrylate copolymer.
Claim 8
Dependent Claim
14 words
The film of claim 1 wherein said third layer comprises ethylene vinyl acetate copolymer.
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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) | 1989-08-25 | 1990-02-24 | 1990-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-25 | 1994-02-24 | 1994-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-25 | 1998-02-24 | 1998-08-26 | $7700.00 | Window Closed / Lapsed |