US3912840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microporous sheet having suede-like surface and method of making
Assignee: 3M Co
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Filing: 1974-10-15
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Granted: 1975-10-14
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Expires: 1994-10-15
Abstract
Abstract Microporous polymeric sheets having a suede-like surface are disclosed. The microporous sheets comprise a first microporous portion and a second macroporous portion overlying and chemically integral with the first portion. The second macroporous portion contains micropores and in addition at least 50% of its volume comprises randomly oriented macrovoids distributed throughout. A sufficient number of the voids are in open communication with the surface of the polymer sheet to provide a suede-like surface. The sheet may be adhered to a supporting substrate to improve body and toughness. The sheets are prepared by immobilizing a polymeric solvent coating and removing the solvent and removable particulate filler and/or surface particles therefrom to form a microporous suede-like sheet.
Inventors
- 👤 Ralph C Edberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:03
CPC Classifications
D; D06; D06N; D06N3/00; D06N3/0043; D06N3/0052; C; C08; C08J; C08J9/00; C08J9/26; Y; Y10; Y10S; Y10S428/00; Y10S428/904; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249961; Y10T428/249978
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
87 words
A MICROPOROUS POLYMERIC SHEET HAVING A SUEDE-LIKE SURFACE COMPRISING A FIRST MICROPOROUS PORTION AND A SECOND MACROPOROUS PORTION OVERLYING AND CHEMICALLY INTEGRAL WITH SAID FIRST MICROPOROUS PORTION, SAID SECOND MACROPOROUS PORTION CONTAINING MICROPOROUS AND ADDITIONALLY HAVING AT LEAST 50% OF ITS VOLUME COMPRISING RANDOMLY ORIENTED MACROVOIDS DISTRIBUTED THROUGHOUT SAID SECOND PORTION, SAID RANDOMLY ORIENTED MACROVOIDS HAVING AN AVARAGE VOID VOLUME OF ABOUT 7X10**-8 TO 6.5X**-10 CM3, A SUFFICIENT NUMBER OF SAID VIODS BEING IN OPEN COMMUNICATION WITH THE SURFACE OF THE SHEET TO PROVIDE A SUEDE-LIKE SURFACE.
Claim 2
Dependent Claim
87 words
A MICROPOROUS POLYMERIC SHEET HAVING A SUEDE-LIKE SURFACE COMPRISING A FIRST MICROPOROUS PORTION AND A SECOND MACROPOROUS PORTION OVERLYING AND CHEMICALLY INTEGRAL WITH SAID FIRST MICROPOROUS PORTION, SAID SECOND MACROPOROUS PORTION CONTAINING MICROPOROUS AND ADDITIONALLY HAVING AT LEAST 50% OF ITS VOLUME COMPRISING RANDOMLY ORIENTED MACROVOIDS DISTRIBUTED THROUGHOUT SAID SECOND PORTION, SAID RANDOMLY ORIENTED MACROVOIDS HAVING AN AVARAGE VOID VOLUME OF ABOUT 7X10**-8 TO 6.5X**-10 CM3, A SUFFICIENT NUMBER OF SAID VIODS BEING IN OPEN COMMUNICATION WITH THE SURFACE OF THE SHEET TO PROVIDE A SUEDE-LIKE SURFACE.
Claim 3
Dependent Claim
20 words
A sheet according to claim 1 wherein said first microporous portion is in adherent contact with a porous flexible substrate.
Claim 4
Dependent Claim
18 words
A sheet according to claim 2 wherein said porous flexible substrate is a non-woven web comprising polypropylene fibers.
Claim 5
Independent Claim
104 words
A METHOD OF MAKING A SUEDE-LIKE, POLYMERIC SHEET COMPRISING THE STEPS OF A. APPLYING A POLYMER COATING COMPOSITION TO THE SURFACE OF A SUBSTRATE, SAID COATING COMPOSITION COMPRISING A SOLUTION OF ELASTOMERIC POLYURETHANE POLYMER IN SOLVENT, B. DEPOSITING A SUFFICIENT NUMBER OF REMOVABLE PARTICLES ON SAID POLYMER COATING TO FORM A LAYER COMPLETELY COVERING SAID POLYMER COATING, SAID PARTICLES HAVING AN AVERAGES PARTICLE VOLUME OF ABOUT 7X10**-8 TO 6.5X**10 CM3, C. IMMOBILIZING THE POLYMER COATING AND REMOVING THE SOLVENT FROM THE COATING, D. REMOVING PARTICLES FROM THE POLYMER COATING TO PROVIDE VOIDS IN SAID COATING, AND E. DRYING THE RESULTING SUEDE-LIKE SHEET AS NECESSARY.
Claim 6
Independent Claim
104 words
A METHOD OF MAKING A SUEDE-LIKE, POLYMERIC SHEET COMPRISING THE STEPS OF A. APPLYING A POLYMER COATING COMPOSITION TO THE SURFACE OF A SUBSTRATE, SAID COATING COMPOSITION COMPRISING A SOLUTION OF ELASTOMERIC POLYURETHANE POLYMER IN SOLVENT, B. DEPOSITING A SUFFICIENT NUMBER OF REMOVABLE PARTICLES ON SAID POLYMER COATING TO FORM A LAYER COMPLETELY COVERING SAID POLYMER COATING, SAID PARTICLES HAVING AN AVERAGES PARTICLE VOLUME OF ABOUT 7X10**-8 TO 6.5X**10 CM3, C. IMMOBILIZING THE POLYMER COATING AND REMOVING THE SOLVENT FROM THE COATING, D. REMOVING PARTICLES FROM THE POLYMER COATING TO PROVIDE VOIDS IN SAID COATING, AND E. DRYING THE RESULTING SUEDE-LIKE SHEET AS NECESSARY.
Claim 7
Dependent Claim
30 words
A method according to claim 4 wherein said polymer solution has dispersed therein removable filler particles of a size sufficiently small to create micropores when removed from said immobilized coating.
Claim 8
Dependent Claim
22 words
A method according to claim 4 wherein said method additionally comprises the step of removing the immobilized polymer coating from the substrate.
Claim 9
Dependent Claim
14 words
A method according to claim 4 wherein said substrate is a porous, flexible substrate.
Claim 10
Dependent Claim
18 words
A method according to claim 7 wherein said porous, flexible substrate is a non-woven web comprising polypropylene fibers.
Claim 11
Dependent Claim
23 words
A method according to claim 7 wherein said substrate is primed with a low viscosity polymer solution prior to applying the coating composition.
Claim 12
Dependent Claim
24 words
A method according to claim 9 wherein said low viscosity priming solution comprises a mixture of polyvinyl chloride polymer and polyurethane polymer in solvent.
Claim 13
Dependent Claim
14 words
A method according to claim 5 wherein said removable particles are water soluble particles.
Claim 14
Dependent Claim
13 words
A method according to claim 11 wherein said particles are sodium chloride particles.
Claim 15
Dependent Claim
15 words
A method according to claim 4 wherein said solvent in said coating composition comprises N,N-dimethylformamide.
Claim 16
Dependent Claim
33 words
A method according to claim 13 wherein said polymer coating is immobilized by contact with a liquid which is miscible with said polymer solvent and which is not a solvent for said polymer.
Claim 17
Dependent Claim
11 words
A method according to claim 14 wherein said liquid is water.
Claim 18
Dependent Claim
20 words
A method according to claim 4 wherein said polymer coating is immobilized by evaporation of said solvent from said coating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-13 | 1979-04-14 | 1979-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-13 | 1983-04-14 | 1983-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-13 | 1987-04-14 | 1987-10-14 | $7700.00 | Window Closed / Lapsed |