US4596738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymer blend films
Assignee: Smith and Nephew PLC
•
Filing: 1984-10-17
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Granted: 1986-06-24
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Expires: 2004-10-17
Abstract
Abstract A moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids characterized in that the blend comprises a continuous matrix of ethylene vinyl acetate within which the incompatible polymer forms a discrete particulate phase matrix, processes for the preparation thereof and articles comprising these films are described.
Inventors
- 👤 Peter J. Metcalfe
- 👤 Andrew J. Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:28
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/18; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/225; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/08; C08L23/0846; C08L23/0853; C08J2331/00; C08J2331/02; C08J2331/04; C08L25/00; C08L25/02; C08L25/04; C08L25/06; Y; Y10; Y10S; Y10S602/00; Y10S602/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/249921; Y10T428/249953; Y10T428/249955; Y10T428/249958; Y10T428/249978; Y10T428/249987; Y10T428/249991
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
50 words
A moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids within the film, said voids not providing a continuous pathway through the film, and wherein the blend comprises a continuous matrix ethylene-vinyl acetate copolymer within which the incompatible polymer forms a discrete particulate phase.
Claim 2
Dependent Claim
50 words
A moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids within the film, said voids not providing a continuous pathway through the film, and wherein the blend comprises a continuous matrix ethylene-vinyl acetate copolymer within which the incompatible polymer forms a discrete particulate phase.
Claim 3
Dependent Claim
13 words
A film according to claim 1 in the form of a wound dressing.
Claim 4
Dependent Claim
36 words
A film according to claim 1 which is liquid water impermeable and has a moisture vapor transmission rate of at least 500 g/m 2 /24 hours at 37° C. at 100% to 20% relative humidity difference.
Claim 5
Dependent Claim
28 words
A film according to claim 1 in which the polymer blend contains 40% to 90% by weight of ethylene-vinyl acetate copolymer and in which the film is apertured.
Claim 6
Dependent Claim
32 words
A film according to claim 4 which is in the form of a net and in which the area of apertures is 10% to 50% of the total area of the film.
Claim 7
Dependent Claim
21 words
A film according to claim 1 in which the polymer blend comprises 40% to 90% by weight of ethylene-vinyl acetate copolymer.
Claim 8
Dependent Claim
13 words
A film according to claim 1 in which the incompatible polymer comprises polystyrene.
Claim 9
Dependent Claim
60 words
A wound dressing or hygenic absorbent pad which comprises a moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids within the film, said voids not providing a continuous pathway through the film, and wherein the blend comprises a continuous matrix of ethylene-vinly acetate copolymer within which the incompatible polymer forms a discrete particulate phase.
Claim 10
Dependent Claim
60 words
A wound dressing or hygenic absorbent pad which comprises a moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids within the film, said voids not providing a continuous pathway through the film, and wherein the blend comprises a continuous matrix of ethylene-vinly acetate copolymer within which the incompatible polymer forms a discrete particulate phase.
Claim 11
Dependent Claim
23 words
A wound dressing according to claim 8 which comprises a moisture vapor transmitting elastomeric film coated on one side with an adhesive layer.
Claim 12
Dependent Claim
14 words
A wound dressing according to claim 2 wherein one surface is coated with adhesive.
Claim 13
Dependent Claim
42 words
A wound dressing according to claim 10 in which the adhesive is moisture vapor transmitting and the dressing has a moisture vapor transmission rate of at least 500 g/m 2 /24 hours at 37° C. at 100% to 10% relative humidity difference.
Claim 14
Dependent Claim
20 words
A wound dressing according to claim 10 in which the adhesive is continuous and is 12.5 to 75 microns thick.
Claim 15
Dependent Claim
16 words
A wound dressing according to claim 12 in which the adhesive comprises an acrylate ester copolymer.
Claim 16
Dependent Claim
84 words
A process for producing a moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids within the film, said voids not providing a continuous pathway through the film, and wherein the blend comprises a continuous matrix of ethylene-vinyl acetate copolymer within which the incompatible polymer forms a discrete particulate phase, which process comprises forming a film from the blend of ethylene-vinyl acetate and incompatible polymer, cold drawing the film until voiding occurs and allowing the drawn film to contract.
Claim 17
Dependent Claim
84 words
A process for producing a moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids within the film, said voids not providing a continuous pathway through the film, and wherein the blend comprises a continuous matrix of ethylene-vinyl acetate copolymer within which the incompatible polymer forms a discrete particulate phase, which process comprises forming a film from the blend of ethylene-vinyl acetate and incompatible polymer, cold drawing the film until voiding occurs and allowing the drawn film to contract.
Claim 18
Dependent Claim
35 words
A process according to claim 14 which additionally comprises forming in the film of ethylene-vinyl acetate copolymer and incompatible polymer thicker and thinner areas and stretching the film until apertures form in the thinner areas.
References Cited (Backward Citations)
US31887A
Cited
US31886A
Cited
GB914489A
Cited
GB1055963A
Cited
US3387077A
Cited
GB1110051A
Cited
GB1075487A
Cited
USRE31887E
Cited
US3645835A
Cited
USRE31886E
Cited
US3939237A
Cited
US4105737A
Cited
US4381326A
Cited
US4483965A
Cited
US4452845A
Cited
GB2081721A
Cited
GB2103537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-23 | 1989-12-23 | 1990-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-23 | 1993-12-23 | 1994-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-23 | 1997-12-23 | 1998-06-24 | $7700.00 | Window Closed / Lapsed |