US4052550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Poly(vinylidene fluoride) yarns and fibers
Assignee: Rhone Poulenc Textile SA
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Filing: 1976-01-29
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Granted: 1977-10-04
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Expires: 1996-01-29
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
2026-10-25 20:46
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/08; D01F6/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
146 words
Polyvinylidene fluoride yarns and fibers having a dry tenacity of at least 33 g/tex and an improved structure as measured by their secondary swelling values of up to 20% prepared by spinning a solution of polyvinylidene fluoride having a fluidity index at 250° C of at least 10 into a coagulating bath containing 45 to 60% by weight of an aprotic polar organic solvent and 40 to 55% by weight of water maintained at a temperature between 15° and 40° C, stretching the filaments in air at a temperature between 15° and 40° C to a ratio of between 1.5× and 5×, then stretching the filaments in boiling water to a ratio of between 1.5× and 4×, the overall stretch ratio being between 3× and 6.5×, and then washing the filaments with water maintained at a temperature between 15° C and 40° C at room temperature.
Claim 2
Dependent Claim
146 words
Polyvinylidene fluoride yarns and fibers having a dry tenacity of at least 33 g/tex and an improved structure as measured by their secondary swelling values of up to 20% prepared by spinning a solution of polyvinylidene fluoride having a fluidity index at 250° C of at least 10 into a coagulating bath containing 45 to 60% by weight of an aprotic polar organic solvent and 40 to 55% by weight of water maintained at a temperature between 15° and 40° C, stretching the filaments in air at a temperature between 15° and 40° C to a ratio of between 1.5× and 5×, then stretching the filaments in boiling water to a ratio of between 1.5× and 4×, the overall stretch ratio being between 3× and 6.5×, and then washing the filaments with water maintained at a temperature between 15° C and 40° C at room temperature.
Claim 3
Dependent Claim
16 words
The yarns and fibers of claim 1 wherein said fluidity index is between 100 and 5,000.
Claim 4
Dependent Claim
17 words
The yarns and fibers of claim 1 wherein the secondary swelling value is no greater than 15%.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |