Patent CA993970A successfully refreshed from Google Patents.
US3965232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the obtaining of poly(vinylidene fluorine) yarns and fibers
Assignee: Rhone Poulenc Textile SA
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Filing: 1974-05-30
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Granted: 1976-06-22
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Expires: 1994-05-30
Abstract
Abstract A process of making polyvinylidene fluoride yarns and fibers of homogeneous structure and good dry strength includes the steps of spinning the solution of the polymer into a coagulating bath containing 45 to 60% by weight aprotic polar organic solvent and 40 to 55% by weight water, stretching the filaments in air to a ratio of 1.5 to 5x and then in boiling water to a ratio of 1.5 to 4x (overall stretching ratio of 3x to 6.5x) and then washing in water at room temperature.
Inventors
- 👤 Pierre Chion
- 👤 Robert Cuidard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:27
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/08; D01F6/12; D01F6/28; D01F6/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
A process of making polyvinylidene fluoride yarns and fibers of improved structure and dry tenacity of more than 33 grams/tex, said process comprising: spinning a solution of polyvinylidene fluoride into a coagulating bath containing 45 to 60% by weight aprotic polar organic solvent and 40 to 55% by weight of water maintained between 15° and 40°C, stretching the filaments in air between 15°C and 40°C to a ratio of between 1.5x and 5x, then stretching the filaments in boiling water to a ratio of between 1.5x and 4x, the overall stretch ratio being between 3x and 6.5x, and then washing the filaments with water maintained between 15°C and 40°C at room temperature.
Claim 2
Dependent Claim
112 words
A process of making polyvinylidene fluoride yarns and fibers of improved structure and dry tenacity of more than 33 grams/tex, said process comprising: spinning a solution of polyvinylidene fluoride into a coagulating bath containing 45 to 60% by weight aprotic polar organic solvent and 40 to 55% by weight of water maintained between 15° and 40°C, stretching the filaments in air between 15°C and 40°C to a ratio of between 1.5x and 5x, then stretching the filaments in boiling water to a ratio of between 1.5x and 4x, the overall stretch ratio being between 3x and 6.5x, and then washing the filaments with water maintained between 15°C and 40°C at room temperature.
Claim 3
Dependent Claim
15 words
The process as claimed in claim 1, wherein: the aprotic polar organic solvent is dimethylformamide.
Claim 4
Dependent Claim
15 words
The process as claimed in claim 1, wherein: the aprotic polar organic solvent is dimethylacetamide.
Claim 5
Dependent Claim
21 words
The process as claimed in claim 1, wherein: the stretching in air is to a ratio of between 3x and 4x.
Claim 6
Dependent Claim
28 words
The process as claimed in claim 1, further comprising: after washing, over-stretching the filaments to a ratio of 1.15x to 1.40x at a temperature of 140° to 160°C.
Claim 7
Dependent Claim
21 words
The process as claimed in claim 1, wherein: after washing, stabilizing the filaments at a temperature of between 140° and 160°C.
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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) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |