US4357437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of water-soluble hydrolyzed products of polyacrylonitrile polymers
Assignee: Dow Produktions und Vertriebs GmbH and Co OHG
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Filing: 1981-07-23
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Granted: 1982-11-02
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Expires: 2001-07-23
Abstract
Abstract A process for the production of water-soluble hydrolyzed polyacrylonitrile polymers, wherein the acrylonitrile is polymerized in the presence of 1-8% by weight of hydrolyzed polyacrylonitrile and hydrolyzed without intermediate isolation from the reaction mixture.
Inventors
- 👤 Helmut Huhn
- 👤 Werner Karstens
- 👤 Lutz Hoppe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:31
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
80 words
A process for the production of a watersoluble hydrolysis product of an acrylonitrile homopolymer and/or copolymer which comprises polymerising acrylonitrile and, optionally, other monomers, in aqueous media, at a temperature of from 35° C. to 80° C. in the presence of from 1 to 8% by weight, based on the monomer to be polymerised of a hydrolysed acrylonitrile homopolymer and/or copolymer having an intrinsic viscisity [η] of from 0.8 to 2.5 dl/g as protective colloid and hydrolysing the resulting polymer.
Claim 2
Dependent Claim
80 words
A process for the production of a watersoluble hydrolysis product of an acrylonitrile homopolymer and/or copolymer which comprises polymerising acrylonitrile and, optionally, other monomers, in aqueous media, at a temperature of from 35° C. to 80° C. in the presence of from 1 to 8% by weight, based on the monomer to be polymerised of a hydrolysed acrylonitrile homopolymer and/or copolymer having an intrinsic viscisity [η] of from 0.8 to 2.5 dl/g as protective colloid and hydrolysing the resulting polymer.
Claim 3
Dependent Claim
20 words
A process as claimed in claim 1, wherein the resulting polymer is hydrolysed without being isolated from the reaction mixture.
Claim 4
Dependent Claim
15 words
A process as claimed in claim 1, wherein polymerisation is carried out by suspension polymerisation.
Claim 5
Dependent Claim
22 words
A process as claimed in claim 3, wherein the proportion of organic substances to water is from 30 to 40% by weight.
Claim 6
Dependent Claim
22 words
A process as claimed in claim 1, wherein from 1 to 8% by weight of isopropanol are added to the polymerisation mixture.
Claim 7
Dependent Claim
21 words
A process as claimed in claim 1, wherein hydrolysis is carried out at a temperature of 180° C. to 200° C.
Claim 8
Dependent Claim
51 words
A process as claimed in claim 1 wherein as protective colloid a hydrolysed polyacrylonitrile homopolymer and/or copolymer consisting of 45 to 60% by weight of ammonium acrylate units and 40 to 55% by weight of acrylic acid amide units, with an intrinsic viscosity of from 1 to 2 dl/g is used.
Claim 9
Dependent Claim
30 words
A process as claimed in claim 1, wherein as protective colloid a hydrolysed polyacrylonitrile homopolymer and/or copolymer is used which is identical with the homo- or copolymer to be produced.
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) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |