US4524099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coextruded elastomeric films
Assignee: Bemis Clysar Inc
•
Filing: 1983-08-30
•
Granted: 1985-06-18
•
Expires: 2003-08-30
Abstract
Abstract A transparent, elastomeric, composite film structure having a core ethylene/vinyl acetate copolymer and outer layers of a low density ethylene homopolymer or copolymer with a small amount of another α-olefin or vinyl acetate is made by coextrusion of the polymers in a three-layer combining adapter and quenching on a chill roll. This film structure is useful as a wrapping material, especially for heat-sensitive articles.
Inventors
- 👤 Robert C. Di Luccio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:55
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; Y; Y10; Y10S; Y10S428/00; Y10S428/906; Y10S428/913; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/31504; Y10T428/31725; Y10T428/3175; Y10T428/31757; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31928
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
122 words
A transparent, elastomeric composite film structure having nontacky surface properties, said film structure comprising a core layer of an ethylene/vinyl acetate copolymer containing about 30-50 weight percent of vinyl acetate and two outer layers, coextruded with said core layer, of a polymeric material selected from the class consisting of homopolyethylene and copolymers of ethylene with up to 10% by weight of the copolymer of a C 3 -C 8 α-olefin or vinyl acetate, said outer layer polymeric material having a density of at most about 0.94 g/cm 3 , said two outer layers providing about 0.5-10% of the total thickness of said composite film structure, which structure following coextrusion is exposed to high energy radiation of which it absorbs about 4-16 megarads.
Claim 2
Dependent Claim
122 words
A transparent, elastomeric composite film structure having nontacky surface properties, said film structure comprising a core layer of an ethylene/vinyl acetate copolymer containing about 30-50 weight percent of vinyl acetate and two outer layers, coextruded with said core layer, of a polymeric material selected from the class consisting of homopolyethylene and copolymers of ethylene with up to 10% by weight of the copolymer of a C 3 -C 8 α-olefin or vinyl acetate, said outer layer polymeric material having a density of at most about 0.94 g/cm 3 , said two outer layers providing about 0.5-10% of the total thickness of said composite film structure, which structure following coextrusion is exposed to high energy radiation of which it absorbs about 4-16 megarads.
Claim 3
Dependent Claim
20 words
A composite structure of claim 1 wherein the two outer layers provide at most about 6% of the total thickness.
Claim 4
Dependent Claim
25 words
A composite structure of claim 1 or 2 wherein the core copolymer contains about 1-3 weight percent of a long chain aliphatic amide or bisamide.
Claim 5
Dependent Claim
25 words
A composite structure of claim 3 wherein the amide or bisamide is selected from the class consisting of stearamide, oleamide, erucamide, palmitamide, ethylenebis(oleamide), and ethylenebis(erucamide).
Claim 6
Dependent Claim
26 words
A composite structure of claim 3 wherein the thickness of at least one outer layer is less than about 1% of the total composite structure thickness.
Claim 7
Dependent Claim
29 words
A composite structure of claim 1 or 2 wherein the core copolymer is a copolymer of about 60 weight percent of ethylene and 40 weight percent of vinyl acetate.
Claim 8
Dependent Claim
23 words
A composite structure of claim 1 or 2 wherein the outer layer polymeric material is a linear copolymer of ethylene with an α-olefin.
Claim 9
Dependent Claim
13 words
An article wrapped in a composite film structure of claim 1 or 2.
Claim 10
Dependent Claim
8 words
An article of claim 8 which is heat-sensitive.
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) | 1988-06-17 | 1988-12-17 | 1989-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-17 | 1992-12-17 | 1993-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-17 | 1996-12-17 | 1997-06-18 | $7700.00 | Window Closed / Lapsed |