Patent US2040168A successfully refreshed from Google Patents.
US2984869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved method of producing micro-porous sheet
Assignee: Pritchett and Gold and EPS Co Ltd
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Filing: 1959-04-27
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Granted: 1961-05-23
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Expires: 1979-04-27
Abstract
No abstract record available.
Inventors
- 👤 Honey Eric Maurice O'conor
- 👤 Hardy Charles Rupert
- 👤 Sharp Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:25
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06; Y; Y10; Y10S; Y10S521/00; Y10S521/919
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
178 words
THE PRODUCTION OF A MICRO-POROUS PLASTIC SHEET COMPRISING MIXING TOGETHER P.V.C POWDER CONTAINING PARTICLES OF UP TO 150 MICRONS DIAMETER, A PLASTICIZER FOR THE P.V.C, POWDERED SODIUM CHLORIDE I AMOUNT AT LEAST EQUAL TO ONE AND A HALF TIMES THE WEIGHT OF THE P.V.C., THE PARTICLE SIZE OF THE SODIUM CHLORIDE FOR A SHEET OF 1 MIL TO 5 MILS IN THICKNESS BEING 5 TO 10 MICRONS AND FOR A SHEET OF 6 MILS THICKNESS AND UPWARDS OF 10 TO 80 MICRONS, AND A VOLATILE SOLVENT OF THE GROUP CONSISTING OF WHITE SPIRIT AND SOLVENT NAPHTHAL FOR THE PLASTICIZER WHEREBY A CREAM OF SMOOTH WORKABLE CONSISTENCY IS PRODUCED, REMOVING ENTRAPPED AIR FROM THE CREAM, SPREADING SAID CREAM ON AN ENDLESS TRAVELLING BELT, REMOVING THE SOLVENT FROM THE CREAM BY EVAPORATION AT A TEMPERATURE BELOW GELATION, HEATING THE SOLVENT FREE SHEET SO FORMED FOR SEVERAL MINUTES AT A TEMPERATUR OF ABOUT 170*C. TO CAUSE THE P.V.C. AND PLASTICIZER TO GEL, COOLING THE SHEET, REMOVING IT FROM THE BELT, LEACHING THE SODIUM CHLORIDE FROM THE SHEET, AND DRYING THE SHEET.
Claim 2
Dependent Claim
178 words
THE PRODUCTION OF A MICRO-POROUS PLASTIC SHEET COMPRISING MIXING TOGETHER P.V.C POWDER CONTAINING PARTICLES OF UP TO 150 MICRONS DIAMETER, A PLASTICIZER FOR THE P.V.C, POWDERED SODIUM CHLORIDE I AMOUNT AT LEAST EQUAL TO ONE AND A HALF TIMES THE WEIGHT OF THE P.V.C., THE PARTICLE SIZE OF THE SODIUM CHLORIDE FOR A SHEET OF 1 MIL TO 5 MILS IN THICKNESS BEING 5 TO 10 MICRONS AND FOR A SHEET OF 6 MILS THICKNESS AND UPWARDS OF 10 TO 80 MICRONS, AND A VOLATILE SOLVENT OF THE GROUP CONSISTING OF WHITE SPIRIT AND SOLVENT NAPHTHAL FOR THE PLASTICIZER WHEREBY A CREAM OF SMOOTH WORKABLE CONSISTENCY IS PRODUCED, REMOVING ENTRAPPED AIR FROM THE CREAM, SPREADING SAID CREAM ON AN ENDLESS TRAVELLING BELT, REMOVING THE SOLVENT FROM THE CREAM BY EVAPORATION AT A TEMPERATURE BELOW GELATION, HEATING THE SOLVENT FREE SHEET SO FORMED FOR SEVERAL MINUTES AT A TEMPERATUR OF ABOUT 170*C. TO CAUSE THE P.V.C. AND PLASTICIZER TO GEL, COOLING THE SHEET, REMOVING IT FROM THE BELT, LEACHING THE SODIUM CHLORIDE FROM THE SHEET, AND DRYING THE SHEET.
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) | 1964-05-22 | 1964-11-21 | 1965-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-05-22 | 1968-11-21 | 1969-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-05-22 | 1972-11-21 | 1973-05-23 | $7700.00 | Window Closed / Lapsed |