US4337328A
Expired / Lapsed
US
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Acrylic polymers having a high swellability in water
Assignee: Hoechst AG
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Filing: 1981-03-04
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Granted: 1982-06-29
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Expires: 2001-03-04
Abstract
Abstract This invention relates to a process for the preparation of acrylic polymers which are at least for the most part insoluble in water and have a high swellability in water, by reacting polyacrylonitrile or copolymers based on acrylonitrile at a temperature exceeding 100° C. with aqueous-alkaline solutions which may contain an organic solvent which is miscible with water.
Inventors
- 👤 Arno Holst
- 👤 Eberhard Perplies
- 👤 Gerhard Buchberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:07
CPC Classifications
D; D06; D06M; D06M13/00; D06M13/10; D06M13/144; D06M13/148; C; C08; C08F; C08F8/00; C08F8/44; D06M11/00; D06M11/32; D06M11/36; D06M11/38
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
65 words
Acrylic polymers which are (a) more than 50 percent by weight insoluble in water, (b) have a high swellability in water, and (c) have degrees of substitution (DS) of DS amide from 0.05 to 0.20 and DS carboxylate from 0.002 to 0.15, said acrylic polymers being produced by reacting polyacrylonitrile or copolymers based on acrylonitrile with an aqueous-alkaline solution at a temperature exceeding 100° C.
Claim 2
Dependent Claim
65 words
Acrylic polymers which are (a) more than 50 percent by weight insoluble in water, (b) have a high swellability in water, and (c) have degrees of substitution (DS) of DS amide from 0.05 to 0.20 and DS carboxylate from 0.002 to 0.15, said acrylic polymers being produced by reacting polyacrylonitrile or copolymers based on acrylonitrile with an aqueous-alkaline solution at a temperature exceeding 100° C.
Claim 3
Dependent Claim
22 words
Acrylic polymers as claimed in claim 1 produced in an aqueous-alkaline solution which contains an organic solvent which is miscible with water.
Claim 4
Dependent Claim
18 words
Acrylic polymers as claimed in claim 1 which are more than 80 percent by weight insoluble in water.
Claim 5
Dependent Claim
38 words
Acrylic polymers as claimed in claim 2 produced in an aqueous-alkaline solution which contains an alcohol selected from the group consisting of monovalent and polyvalent aliphatic and cycloaliphatic alcohols having a boiling point of at least 110° C.
Claim 6
Dependent Claim
27 words
Acrylic polymers as claimed in claim 4 produced in an aqueous-alkaline solution which contains an alcohol selected from the group consisting of n-butanol, cyclohexanol, glycol and glycerol.
Claim 7
Dependent Claim
17 words
Acrylic polymers as claimed in claim 1 produced by reacting said polymer or copolymer under superatmospheric pressure.
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) | 1985-06-28 | 1985-12-28 | 1986-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-28 | 1989-12-28 | 1990-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-28 | 1993-12-28 | 1994-06-29 | $7700.00 | Window Closed / Lapsed |