Patent EP0046071A2 successfully refreshed from Google Patents.
EP0046071A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Polymer blend films, their preparation and use
Assignee: Smith and Nephew PLC
•
Filing: 1981-08-07
•
Granted: —
•
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 21:46
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.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.