US4560522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing poly-piperazinamide anisotropic shaped articles
Assignee: Montedison SpA
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Filing: 1983-06-30
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Granted: 1985-12-24
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Expires: 2003-06-30
Abstract
Abstract Process for preparing poly-piperazinamide, anisotropic shaped articles comprising the preparation of the polymer solution in a polar organic solvent, the transformation of the solution into shaped bodies by spreading or spinning, the gelation of the shaped articles by phase inversion, and, optionally, the heat treatment of the gellified shaped articles.
Inventors
- 👤 Catia Bastioli
- 👤 Giuseppe Gianotti
- 👤 Adriano Mattera
- 👤 Paolo Parrini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:50
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/56; D; D01; D01D; D01D5/00; D01D5/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A process for the preparation of polypiperazinamide anisotropic shaped articles suitable for reverse osmosis consisting of: (a) preparing a solution of a polypiperazinamide in an organic polar solvent; (b) transforming said solution into a shaped article by spreading it onto a flat or tubular support, or by extruding it through a spinneret for hollow fibers; (c) gelating the shaped articles by phase inversion, by passage thereof through a coagulating bath selected from the group consisting of polyfunctional alcohols, mixtures of polyfunctional alcohols with a quantity of water not exceeding 20% by weight, and aqueous solutions of electrolytes in a concentration of 10% to 40% by weight, and, optionally (d) heat-treating the shaped article thus obtained.
Claim 2
Dependent Claim
115 words
A process for the preparation of polypiperazinamide anisotropic shaped articles suitable for reverse osmosis consisting of: (a) preparing a solution of a polypiperazinamide in an organic polar solvent; (b) transforming said solution into a shaped article by spreading it onto a flat or tubular support, or by extruding it through a spinneret for hollow fibers; (c) gelating the shaped articles by phase inversion, by passage thereof through a coagulating bath selected from the group consisting of polyfunctional alcohols, mixtures of polyfunctional alcohols with a quantity of water not exceeding 20% by weight, and aqueous solutions of electrolytes in a concentration of 10% to 40% by weight, and, optionally (d) heat-treating the shaped article thus obtained.
Claim 3
Dependent Claim
46 words
A process according to claim 1, wherein the solvents for the preparation of the spinning solution are miscible with water and belonging to classes m and s of the solvents forming hydrogen bonds (m-H and s-H bounding groups) and have a solubility parameter >8 (cal/cc) 1/2.
Claim 4
Dependent Claim
21 words
A process according to claim 1, wherein the concentration of the solution (a) is comprised between 5% and 30% by weight.
Claim 5
Dependent Claim
20 words
A process according to claim 3, wherein the concentration of the solution is comprised between 8% and 20% by weight.
Claim 6
Dependent Claim
35 words
A process according to claim 1, wherein the solution (a) contains quantity not exceeding 5% by weight with respect to the solution of an inorganic salt or an organic compound with a high boiling point.
Claim 7
Dependent Claim
22 words
A process according to claim 1, wherein the coagulating bath is maintained at a temperature comprised between -20° C. and +40° C.
Claim 8
Dependent Claim
52 words
A process according to claim 1, in which the shaped article is subjected to heat treatment (d) by immersing the shaped article in a glycol or glycerin bath, keeping the bath first at room temperature for 3-12 hours, and then at a temperature of 40° C. to 100° C. for 1-120 minutes.
References Cited (Backward Citations)
US3551331A
Cited
US3710945A
Cited
US3878109A
Cited
JPS50107210A
Cited
US4087388A
Cited
JPS53143725A
Cited
US4340479A
Cited
US4340479B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |