US5032326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash-spinning of polymeric plexifilaments
Assignee: EIDP Inc
•
Filing: 1989-07-14
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Granted: 1991-07-16
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Expires: 2009-07-14
Abstract
Abstract An improved process for flash-spinning plexifilamentary film-fibril strands is provided. A 5 to 30 and preferably 10 to 20 percent solution of polymer, preferably linear polyethylene, is formed in a spin fluid that consists essentially of 50 to 90 weight percent methylene chloride and 10 to 50 percent of a halocarbon, which preferably is chlorodifluoromethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoro-2-chloroethane or 1,1-difluoro-1-chloroethane. The solution is then flash-spun to form high quality plexifilamentary strands. The process avoids the use of halocarbon solvents that could be ozone-depletion hazards.
Inventors
- 👤 Hyunkook Shin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:27
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/42; D01D5/11; D01F; D01F6/00; D01F6/02; D01F6/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
148 words
An improved process for flash-spinning plexifilamentary film-fibril strands of synthetic fiber-forming polymer wherein the polymer is mixed with a spin fluid consisting essentially of methylene chloride and a co-solvent to form a spin mixture containing 5 to 30 weight percent of polymer which mixture is then flash-spun at a pressure that is greater than the autogenous pressure of the spin fluid into a region of substantially lower temperature and pressure, the improvement comprising, in combination, the co-solvent being a halocarbon of 1, 2 or 3 carbon atoms and at least one hydrogen atom, having a boiling point in the range of 0° to -50° C. and amounting to 10 to 50 percent by weight of the spin fluid and the mixing and the flash-spinning being performed at a temperature in the range of 130° to 240° C. and a pressure in the range of 500 to 5,000 psia.
Claim 2
Dependent Claim
148 words
An improved process for flash-spinning plexifilamentary film-fibril strands of synthetic fiber-forming polymer wherein the polymer is mixed with a spin fluid consisting essentially of methylene chloride and a co-solvent to form a spin mixture containing 5 to 30 weight percent of polymer which mixture is then flash-spun at a pressure that is greater than the autogenous pressure of the spin fluid into a region of substantially lower temperature and pressure, the improvement comprising, in combination, the co-solvent being a halocarbon of 1, 2 or 3 carbon atoms and at least one hydrogen atom, having a boiling point in the range of 0° to -50° C. and amounting to 10 to 50 percent by weight of the spin fluid and the mixing and the flash-spinning being performed at a temperature in the range of 130° to 240° C. and a pressure in the range of 500 to 5,000 psia.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the halocarbon is selected from the group consisting of chlorodifluoromethane, 1,1,1,2-tetrafluoroethane, 1,1-difluoroethane, 1,1,1,2-tetrafluoro-2-chloroethane and 1,1-difluoro-1-chloroethane.
Claim 4
Dependent Claim
11 words
The process of claim 2 wherein the polymer is linear polyethylene.
Claim 5
Dependent Claim
11 words
The process of claim 2 wherein the polymer is isotactic polypropylene.
Claim 6
Dependent Claim
50 words
The process of claim 3 wherein the halocarbon amount to 10 to 35 percent by weight of the spin fluid and the mixing and the flash-spinning are performed at a temperature in the range of 140° to 220° C. and a pressure in the range of 800 to 2,500 psia.
Claim 7
Dependent Claim
51 words
The process of claim 4 wherein the halocarbon amounts to 10 to 35 percent by weight of the spin fluid and the mixing and the flash spinning are performed at a temperature in the range of 140° to 220° C. and a pressure in the range of 800 to 2,500 psia.
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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) | 1994-07-15 | 1995-01-14 | 1995-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-15 | 1999-01-14 | 1999-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-15 | 2003-01-14 | 2003-07-16 | $7700.00 | Window Closed / Lapsed |