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US4613544A
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Waterproof, moisture-vapor permeable sheet material and method of making the same
Assignee: 3M Co
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Filing: 1984-12-04
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Granted: 1986-09-23
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Expires: 2004-12-04
Abstract
Abstract A waterproof, moisture-vapor permeable unitary sheet material comprises a microporous polymeric matrix having pores comprising continuous passages extending through its thickness and opening into the opposite surfaces thereof, the passages being sufficiently filled with a moisture-vapor permeable, water-impermeable, hydrophilic material to prevent the passage of water and other liquids through the unitary sheet material while readily permitting moisture vapor transmission therethrough rendering the sheet material breathable. The unitary sheet is made by causing a liquid composition comprising the hydrophilic material or precursor thereof to flow into the pores of the matrix, then causing the conversion thereof to solid hydrophilic material.
Inventors
- 👤 Malcolm B. Burleigh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:04
CPC Classifications
D; D06; D06N; D06N7/00; D06N3/00; D06N3/04; D06N3/047; A; A61; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/24; A61L15/26; A61L15/42; A61L15/425; C; C08; C08J; C08J5/00; C08J5/18; C08J9/00; C08J9/36; C08J9/40; C08J9/42; C08J2475/00; Y; Y10; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249981; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
51 words
A waterproof, moisture-vapor permeable unitary sheet material comprising a microporous polymeric matrix having continuous pores comprising continuous passages extending through its thickness and opening into both surfaces thereof, said pores being sufficiently filled with a moisture-vapor permeable, water-impermeable, hydrophilic material to prevent the passage of water through said unitary sheet material.
Claim 2
Dependent Claim
51 words
A waterproof, moisture-vapor permeable unitary sheet material comprising a microporous polymeric matrix having continuous pores comprising continuous passages extending through its thickness and opening into both surfaces thereof, said pores being sufficiently filled with a moisture-vapor permeable, water-impermeable, hydrophilic material to prevent the passage of water through said unitary sheet material.
Claim 3
Dependent Claim
19 words
The unitary sheet material of claim 1 wherein the polymeric material forming said microporous polymeric matrix is a polyolefin.
Claim 4
Dependent Claim
22 words
The unitary sheet material of claim 2 wherein said polyolefin is a member selected from the group consisting of polyethylene and polypropylene.
Claim 5
Dependent Claim
18 words
The unitary sheet material of claim 1 wherein the polymeric material forming said microporous polymeric matrix is polytetrafluoroethylene.
Claim 6
Dependent Claim
22 words
The unitary sheet material of claim 1 having a moisture vapor transmission rate of at least 1000 g/m 2 per 24 hours.
Claim 7
Dependent Claim
16 words
The unitary sheet material of claim 1 having a thickness of about 5 to 250 micrometers.
Claim 8
Dependent Claim
18 words
The unitary sheet material of claim 1 wherein said hydrophilic material is a polyurethane comprising a polyoxyethylene backbone.
Claim 9
Dependent Claim
11 words
A laminate comprising the sheet material of claim 1 and fabric.
Claim 10
Dependent Claim
8 words
A garment comprising the laminate of claim 8.
Claim 11
Dependent Claim
11 words
A wound dressing comprised of the sheet material of claim 1.
Claim 12
Dependent Claim
53 words
A two phase, homogeneous, waterproof, moisture-vapor permeable, unitary sheet material comprising a microporous polymeric first phase having pores comprising continuous passages opening into the opposite surfaces thereof, and a second phase comprising moisture-vapor permeable, water impermeable, hydrophilic material sufficiently filling said pores to prevent the passage of water through said unitary sheet material.
Claim 13
Dependent Claim
53 words
A two phase, homogeneous, waterproof, moisture-vapor permeable, unitary sheet material comprising a microporous polymeric first phase having pores comprising continuous passages opening into the opposite surfaces thereof, and a second phase comprising moisture-vapor permeable, water impermeable, hydrophilic material sufficiently filling said pores to prevent the passage of water through said unitary sheet material.
Claim 14
Dependent Claim
131 words
Method of making a waterproof, moisture-vapor permeable unitary sheet material, said method comprising the steps of: (a) providing a microporous polymeric matrix having pores extending through its thickness; (b) selecting a hydrophilic material or precursor thereof which when converted to said hydrophilic material is moisture-vapor permeable and water-impermeable; (c) preparing a liquid composition comprising said hydrophilic material or a precursor thereof for flowing into the pores of said matrix; (d) if needed, rendering the polymeric surface of said matrix wettable to said liquid composition; (e) causing the liquid composition to flow into the pores of said matrix; and (f) causing said hydrophilic material or precursor thereof to convert to solid hydrophilic material within said pores to sufficiently fill said pores to prevent the passage of water through said unitary sheet material.
Claim 15
Dependent Claim
131 words
Method of making a waterproof, moisture-vapor permeable unitary sheet material, said method comprising the steps of: (a) providing a microporous polymeric matrix having pores extending through its thickness; (b) selecting a hydrophilic material or precursor thereof which when converted to said hydrophilic material is moisture-vapor permeable and water-impermeable; (c) preparing a liquid composition comprising said hydrophilic material or a precursor thereof for flowing into the pores of said matrix; (d) if needed, rendering the polymeric surface of said matrix wettable to said liquid composition; (e) causing the liquid composition to flow into the pores of said matrix; and (f) causing said hydrophilic material or precursor thereof to convert to solid hydrophilic material within said pores to sufficiently fill said pores to prevent the passage of water through said unitary sheet material.
Claim 16
Dependent Claim
33 words
The method of claim 12 wherein said liquid composition comprises a precursor of said hydrophilic material and said causing to convert comprises in situ polymerizing said precursor to produce said solid hydrophilic material.
Claim 17
Dependent Claim
13 words
The method of claim 13 wherein said precursor is a polyurethane polyoxyethylene prepolymer.
Claim 18
Dependent Claim
26 words
The method of claim 12 wherein said liquid composition comprises a solvent solution of said hydrophilic material and said causing to convert comprises evaporating said solvent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-22 | 1990-03-24 | 1990-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-22 | 1994-03-24 | 1994-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-22 | 1998-03-24 | 1998-09-23 | $7700.00 | Window Closed / Lapsed |