US3879519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash extrusion process
Assignee: EIDP Inc
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Filing: 1973-08-27
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Granted: 1975-04-22
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Expires: 1993-08-27
Abstract
Abstract A flash-extrusion process for preparing plexifilamentary structures of PACM-12 employs a mixed solvent consisting essentially of hexafluoroisopropanol and dichlorofluoromethane.
Inventors
- 👤 Rudolph Woodell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:45
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/11; D01F; D01F6/00; D01F6/58; D01F6/60
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
103 words
A PROCESS FOR PREPARING PLEXIFILAMENTARY STRUCTURES OF POLY(BIS(4-AMINOCYCLOHEXYL)METHANE DODECANEDIAMIDE) COMPRISING FORMING A SOLUTION OF FROM 10 TO 20 PERCENT BY WEIGHT OF THE POLYMER IN A MIXED SOLVENT CONSISTING ESSENTIALLY OF GREATER THAN 50 PERCENT BY WEIGHT OF DICHLOROFLUOROMETHANE AND AT LEAST 10 PERCENT BY WEIGHT OF HEXAFLUOROISOPROPANOL, HEATING SAID SOLUTION TO A TEMPERATURE IN THE RANGE OF 170*-210*C. UNDER A SUPER-AUTOGENOUS PRESSURE SUFFICIENT TO MAINTAIN SAID SOLUTION AS A ONE-PHASE SYSTEM, AND EXTRUDING SAID HEATED SOLUTION INTO A REGION AT SUBSTANTIALLY LOWER PRESSURE WHEREUPON FLASH VAPORIZATION OF SUBSTANTIALLY ALL OF SAID SOLVENT OCCURS AND SOLID POLYMER IS PRECIPITATED AS A PLEXIFILAMENTARY STRUCTURE.
Claim 2
Dependent Claim
103 words
A PROCESS FOR PREPARING PLEXIFILAMENTARY STRUCTURES OF POLY(BIS(4-AMINOCYCLOHEXYL)METHANE DODECANEDIAMIDE) COMPRISING FORMING A SOLUTION OF FROM 10 TO 20 PERCENT BY WEIGHT OF THE POLYMER IN A MIXED SOLVENT CONSISTING ESSENTIALLY OF GREATER THAN 50 PERCENT BY WEIGHT OF DICHLOROFLUOROMETHANE AND AT LEAST 10 PERCENT BY WEIGHT OF HEXAFLUOROISOPROPANOL, HEATING SAID SOLUTION TO A TEMPERATURE IN THE RANGE OF 170*-210*C. UNDER A SUPER-AUTOGENOUS PRESSURE SUFFICIENT TO MAINTAIN SAID SOLUTION AS A ONE-PHASE SYSTEM, AND EXTRUDING SAID HEATED SOLUTION INTO A REGION AT SUBSTANTIALLY LOWER PRESSURE WHEREUPON FLASH VAPORIZATION OF SUBSTANTIALLY ALL OF SAID SOLVENT OCCURS AND SOLID POLYMER IS PRECIPITATED AS A PLEXIFILAMENTARY STRUCTURE.
Claim 3
Dependent Claim
103 words
A process for preparing plexifilamentary structures of poly(bis(4-aminocyclohexyl)methane dodecanediamide) comprising forming a solution of from 10 to 20 percent by weight of the polymer in a mixed solvent consisting essentially of greater than 50 percent by weight of dichlorofluoromethane and at least 10 percent by weight of hexafluoroisopropanol, heating said solution to a temperature in the range of 170*-210*C. under a super-autogenous pressure sufficient to maintain said solution as a one-phase system, and extruding said heated solution into a region at substantially lower pressure whereupon flash vaporization of substantially all of said solvent occurs and solid polymer is precipitated as a plexifilamentary structure.
Claim 4
Dependent Claim
103 words
A process for preparing plexifilamentary structures of poly(bis(4-aminocyclohexyl)methane dodecanediamide) comprising forming a solution of from 10 to 20 percent by weight of the polymer in a mixed solvent consisting essentially of greater than 50 percent by weight of dichlorofluoromethane and at least 10 percent by weight of hexafluoroisopropanol, heating said solution to a temperature in the range of 170*-210*C. under a super-autogenous pressure sufficient to maintain said solution as a one-phase system, and extruding said heated solution into a region at substantially lower pressure whereupon flash vaporization of substantially all of said solvent occurs and solid polymer is precipitated as a plexifilamentary structure.
Claim 5
Dependent Claim
16 words
The process of claim 1 wherein the extrusion temperature is in the range of from 180*-200*C.
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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |