EP0046071A2
Expired / Lapsed
EP
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Polymer blend films, their preparation and use
Assignee: Smith and Nephew PLC
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Filing: 1981-08-07
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Granted: —
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Expires: 2001-08-07
Abstract
Abstract A moisture vapour transmitting film comprising a blend of polyurethane and an incompatible polymer characterised in that the incompatible polymer forms a discrete phase within a continuous matrix of polyurethane and that said film contains voids and processes for the manufacture thereof.
Inventors
- 👤 Ronald Lloyd
- 👤 Peter Joseph Metcalfe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 15:15
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/225; C; C08; C08L; C08L75/00; C08L75/04; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249979; Y10T428/249982; Y10T428/249983; Y10T428/249985; Y10T428/26; Y10T428/268; Y10T428/28
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
38 words
A moisture vapour transmitting elastomeric film comprising a blend of polyurethane and an incompatible polymer characterised in that the incompatible polymer forms a discrete particulate phase within a continuous matrix of polyurethane and that said film contains voids.
Claim 2
Dependent Claim
38 words
A moisture vapour transmitting elastomeric film comprising a blend of polyurethane and an incompatible polymer characterised in that the incompatible polymer forms a discrete particulate phase within a continuous matrix of polyurethane and that said film contains voids.
Claim 3
Dependent Claim
33 words
A moisture vapour transmitting elastomeric film comprising a blend of polyurethane and a discrete particluate phase characterised in that the discrete particulate phase comprises an incompatible polymer and that said film contains voids.
Claim 4
Dependent Claim
33 words
A moisture vapour transmitting elastomeric film comprising a blend of polyurethane and a discrete particluate phase characterised in that the discrete particulate phase comprises an incompatible polymer and that said film contains voids.
Claim 5
Dependent Claim
24 words
A film as claimed in either of claims 1 or 2 in which the voids have a diameter of 2 microns to 12 microns.
Claim 6
Dependent Claim
38 words
A film as claimed in any of claims 1 to 3 in which the film as a moisture vapour transmission rate of at least 350g/m 2 /24 hours at 37°C at 100% - 10 q relative humidity difference.
Claim 7
Dependent Claim
22 words
A film as claimed in any of claims 1 to 4 in which the film has a thickness of 0.0125mm to 0.125mm.
Claim 8
Dependent Claim
24 words
A film as claimed in any of claims 1 to 5 in which the polyurethane comprises 50% to 80% by weight of the film.
Claim 9
Dependent Claim
20 words
A film as claimed in any of claims 1 to 6 in which the incompatible polymer comprises high impact polystyrene.
Claim 10
Dependent Claim
24 words
A film as claimed in any of claims 1 to 6 in which the incompatible polymer comprises a low density polyethylene containing inorganic filler.
Claim 11
Dependent Claim
16 words
A medical dressing which comprises a film as defined in any of claims 1 to 8.
Claim 12
Dependent Claim
11 words
A medical dressing as claimed in'claim 9 coated with an adhesive.
Claim 13
Dependent Claim
44 words
A process of making a film as defined in any of claims 1 to 10 which comprises forming a film from a blend of polyurethane and an incompatible polymer, cold drawing the film until voiding occurs and thereafter allowing the drawn film to contract.
References Cited (Backward Citations)
No citation records indexed.
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