US4726997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemically stabilized film
Assignee: Cryovac LLC
•
Filing: 1986-08-26
•
Granted: 1988-02-23
•
Expires: 2006-08-26
Abstract
Abstract In a multilayer flexible film suitable for medical solution packaging, film-derived extractables are controlled by the use of a small amount of a high molecular weight stabilizer in the outer layer of the film. Solution pH can be controlled by the addition of a carbonate of an alkali metal to at least one intermediate adhesive layer and/or the core layer of the film.
Inventors
- 👤 Walter B. Mueller
- 👤 Henry G. Schirmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:57
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/36; B32B27/18; B32B7/00; B32B7/04; B32B7/12; B32B9/00; B32B9/04; B32B9/045; A; A61; A61J; A61J1/00; A61J1/05; A61J1/10; B32B2439/00; B32B2439/80; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31786; Y10T428/31797
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
78 words
In a multilayer flexible film comprising a sealant layer, a core layer comprising very low density polyethylene, an outer layer of a flexible polyester or copolyester, a first adhesive layer bonding the core layer to the sealant layer, and a second adhesive layer bonding the core layer to the outer layer, the improvement comprising the inclusion in the outer layer of between about 0.3% and 1% by weight of the outer layer of a high molecular weight stabilizer.
Claim 2
Dependent Claim
78 words
In a multilayer flexible film comprising a sealant layer, a core layer comprising very low density polyethylene, an outer layer of a flexible polyester or copolyester, a first adhesive layer bonding the core layer to the sealant layer, and a second adhesive layer bonding the core layer to the outer layer, the improvement comprising the inclusion in the outer layer of between about 0.3% and 1% by weight of the outer layer of a high molecular weight stabilizer.
Claim 3
Dependent Claim
19 words
The improvement according to claim 1 wherein the outer layer includes about 0.7% of a high molecular weight stabilizer.
Claim 4
Independent Claim
85 words
A method of producing a multilayer film comprising: (a) blending a flexible polyester or copolyester with between about 0.3% and 1%, by weight of the polyester or copolyester, of a high molecular weight stabilizer; and (b) coextruding a multilayer film comprising a sealant layer, a core layer comprising very low density polyethylene, an outer layer containing the blend of (a), a first adhesive layer bonding the core layer to the sealant layer, and a second adhesive layer bonding the core layer to the outer layer.
Claim 5
Independent Claim
85 words
A method of producing a multilayer film comprising: (a) blending a flexible polyester or copolyester with between about 0.3% and 1%, by weight of the polyester or copolyester, of a high molecular weight stabilizer; and (b) coextruding a multilayer film comprising a sealant layer, a core layer comprising very low density polyethylene, an outer layer containing the blend of (a), a first adhesive layer bonding the core layer to the sealant layer, and a second adhesive layer bonding the core layer to the outer layer.
Claim 6
Dependent Claim
25 words
The method according to claim 3 wherein about 0.7% of a high molecular weight stabilizer is blended with the polyester or copolyester prior to extrusion.
References Cited (Backward Citations)
US4188443A
Cited
US4528220A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |