Patent US5032326A successfully refreshed from Google Patents.
US5032326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flash-spinning of polymeric plexifilaments
Assignee: EIDP Inc
•
Filing: 1989-07-14
•
Granted: 1991-07-16
•
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 14:11
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.
References Cited (Backward Citations)
GB891943A
Cited
GB891945A
Cited
US3081519A
Cited
US3227794A
Cited
US3467744A
Cited
US3564088A
Cited
US3655498A
Cited
GB1333059A
Cited
US3756441A
Cited
US3879519A
Cited
US4554207A
Cited
JPS6233816A
Cited
JPS62104915A
Cited
JPS62243642A
Cited
JPS62250220A
Cited
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 |