US4876156A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film and sheet capable of forming retortable and easy-open packagings
Assignee: Shell USA Inc
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Filing: 1988-12-16
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Granted: 1989-10-24
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Expires: 2008-12-16
Abstract
Abstract Films or sheets are fabricated from blends of an ethylenic homopolymer or copolymer, a butene-1 homopolymer or copolymer, and a propylene homopolymer or copolymer wherein the weight percent of the homopolymer or copolymer is equal or greater than 25 w % and is less that of the butuene-1 homopolymer or copolymer which result in good peel seal characteristics.
Inventors
- 👤 Charles C. Hwo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:44
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/18; C08L23/20; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
124 words
A laminar structure comprising a polypropylene substrate to which is bonded by extrusion lamination a film or sheet which is capable of forming peel seals, comprising a mixture containing: from about 5 percent by weight to about 25 percent by weight of an ethylenic homopolymer or copolymer selected from the group consisting of linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), ethylene vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA), and high density polyethylene (HDPE); from about 50 percent by weight to about 75 percent by weight of the butene-1 homopolymer or copolymer; and from about 25 percent by weight to about 45 percent by weight of propylene homopolymer or copolymer.
Claim 2
Dependent Claim
124 words
A laminar structure comprising a polypropylene substrate to which is bonded by extrusion lamination a film or sheet which is capable of forming peel seals, comprising a mixture containing: from about 5 percent by weight to about 25 percent by weight of an ethylenic homopolymer or copolymer selected from the group consisting of linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), ethylene vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA), and high density polyethylene (HDPE); from about 50 percent by weight to about 75 percent by weight of the butene-1 homopolymer or copolymer; and from about 25 percent by weight to about 45 percent by weight of propylene homopolymer or copolymer.
Claim 3
Dependent Claim
63 words
The laminar structure of claim 1 which contains: from about 10 percent by weight to about 15 percent by weight of said ethylenic homopolymer or copolymer; from about 55 percent by weight to about 60 percent by weight of said butene-1 homopolymer or copolymer; and from about 25 percent by weight to about 35 percent by weight of said propylene homopolymer or copolymer.
Claim 4
Dependent Claim
41 words
The laminar structure of claim 1 which contains: about 10 percent by weight of said ethylenic homopolymer or copolymer; about 65 percent by weight of said butene-1 homopolymer or copolymer; about 25 percent by weight of said propylene homopolymer or copolymer.
Claim 5
Dependent Claim
15 words
The laminar structure in claim 1, wherein said film or sheet is unoriented or oriented.
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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) | 1992-10-23 | 1993-04-24 | 1993-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-23 | 1997-04-24 | 1997-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-23 | 2001-04-24 | 2001-10-24 | $7700.00 | Window Closed / Lapsed |