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US3890291A
Expired / Lapsed
US
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Alpha-hydroxyacrylic acid/acrylic acid-copolymers and a process for making them
Assignee: Hoechst AG
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Filing: 1974-05-22
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Granted: 1975-06-17
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Expires: 1994-05-22
Abstract
Abstract Copolymers made from Alpha -hydroxyacrylic acid and acrylic acid. The copolymers contain between 9 and 85 mol percent of acrylic acid and have a specific viscosity within the range 0.05 to 1.0, determined on a 1 weight percent solution of the copolymers in aqueous 2N-sodium hydroxide solution, at 20*C.
Inventors
- 👤 Wilhelm Vogt
- 👤 Eberhard Auer
- 👤 Gunter Lenz
- 👤 Karl Merkenich
- 👤 Klaus Henning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:59
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
49 words
A COPOLYMERS OF A-HYDROXYACRYLIC ACID AND ACRYLIC ACID, THE COPOLYMERS CONTAINING BETWEEN ABOUT 9 AND 85 MOL PERCENT OF ACRYLIC ACID AND HAVING A SPECIFIC VISCOSITY SUBSTANTIALLY WITHIN THE RANGE 0.05 AND 1.0, DETERMINED ON 1 WEIGHT PERCENT SOLUTIONS OF THE COPOLYMERS IN AQUEOUS 2N-SODIUM HYDROXIDE SOLUTION AT 20*C.
Claim 2
Dependent Claim
49 words
A COPOLYMERS OF A-HYDROXYACRYLIC ACID AND ACRYLIC ACID, THE COPOLYMERS CONTAINING BETWEEN ABOUT 9 AND 85 MOL PERCENT OF ACRYLIC ACID AND HAVING A SPECIFIC VISCOSITY SUBSTANTIALLY WITHIN THE RANGE 0.05 AND 1.0, DETERMINED ON 1 WEIGHT PERCENT SOLUTIONS OF THE COPOLYMERS IN AQUEOUS 2N-SODIUM HYDROXIDE SOLUTION AT 20*C.
Claim 3
Dependent Claim
45 words
The copolymers as claimed in claim 1, containing between 16 and 50 mol percent of acrylic acid and having a specific viscosity substantially within the range 0.1 and 0.8, determined on 1 weight percent solutions of the copolymers in aqueous 2N-sodium hydroxide solution, at 20*C.
Claim 4
Dependent Claim
14 words
The alkali metal or ammonium salts of the copolymers as claimed in claim 1.
Claim 5
Dependent Claim
11 words
The sodium salts of the copolymers as claimed in claim 3.
Claim 6
Dependent Claim
129 words
A process for making Alpha -hydroxyacrylic acid/acrylic acid-copolymers containing substantially between 9 and 85 mol percent of acrylic acid and having a specific viscosity substantially within the range 0.05 and 1.0, determined on a 1 weight percent solution of the copolymers in aqueous 2N-sodium hydroxide solution, at 20*C, which comprises subjecting the halogen atoms of an Alpha -chloracrylic acid/ acrylic acid-copolymer containing substantially between 9 and 85 mol percent of acrylic acid and having a specific viscosity substantially within the range 0.1 and 1.0, determined on a 1 weight percent solution of the copolymer in dimethyl formamide, at 25*C, to hydrolysis with at least stoichiometric proportions of water at temperatures substantially within the range 80* and 100*C, the hydrolysis being effected with thorough agitation, and separating the resulting hydrolyzate.
Claim 7
Dependent Claim
129 words
A process for making Alpha -hydroxyacrylic acid/acrylic acid-copolymers containing substantially between 9 and 85 mol percent of acrylic acid and having a specific viscosity substantially within the range 0.05 and 1.0, determined on a 1 weight percent solution of the copolymers in aqueous 2N-sodium hydroxide solution, at 20*C, which comprises subjecting the halogen atoms of an Alpha -chloracrylic acid/ acrylic acid-copolymer containing substantially between 9 and 85 mol percent of acrylic acid and having a specific viscosity substantially within the range 0.1 and 1.0, determined on a 1 weight percent solution of the copolymer in dimethyl formamide, at 25*C, to hydrolysis with at least stoichiometric proportions of water at temperatures substantially within the range 80* and 100*C, the hydrolysis being effected with thorough agitation, and separating the resulting hydrolyzate.
Claim 8
Dependent Claim
49 words
The process as claimed in claim 5, wherein the Alpha -chloracrylic acid/acrylic acid-copolymer contains between 16 and 50 mol percent of acrylic acid and has a specific viscosity within the range 0.4 and 0.8, determined on a 1 weight percent solution of the copolymer in dimethyl formamide, at 25*C.
Claim 9
Dependent Claim
28 words
The process as claimed in claim 5, wherein the hydrolysis is effected with the use of between about 10 and 15 g of water, per gram of copolymer.
Claim 10
Dependent Claim
20 words
The process as claimed in claim 5, wherein the hydrolysis is effected at temperatures within the range 90* and 100*C.
Claim 11
Dependent Claim
19 words
The process as claimed in claim 5, wherein the hydrolysis is effected within the range 2 and 3 houRs.
Claim 12
Dependent Claim
28 words
The process as claimed in claim 5, wherein the Alpha -hydroxyacrylic acid/acrylic acid-copolymer is separated from aqueous reaction mixture by filtration or by evaporation of water to dryness.
Claim 13
Dependent Claim
19 words
Complex formers and/or sequestering agents for polyvalent metal ions, consisting essentially of the copolymers as claimed in claim 1.
Claim 14
Dependent Claim
20 words
Complex formers and/or sequestering agents for Ca-ions, Mg-ions or Cu-ions, consisting essentially of the copolymers as claimed in claim 11.
References Cited (Backward Citations)
US2754291A
Cited
US3642718A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |