Patent US4816872A successfully refreshed from Google Patents.
Patent US3890288A successfully refreshed from Google Patents.
US3890288A
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Process for making poly-alpha-oxyacrylic acid and its alkali metal salts
Assignee: Hoechst AG
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Filing: 1974-06-21
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Granted: 1975-06-17
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Expires: 1994-06-21
Abstract
Abstract Production of poly- Alpha -oxyacrylic acid by contacting a solution of Alpha -chloracrylic acid with one or more radicalyielding polymerization catalysts, heating and thereby hydrolyzing the resulting poly- Alpha -chloracrylic acid in queous solution with the resultant precipitation of solid polyAlpha -oxyacrylic acid and separating the poly- Alpha -oxyacrylic acid. More particularly, and aqueous Alpha -chloracrylic acid solution is contacted with the radical-yielding polymerization catalysts for a period of at least 30 minutes and, while leaving the resulting poly- Alpha -chloracrylic acid unseparated, it is heated for a period of at least 1 hour to temperatures within the range 80* and 110*C.
Inventors
- 👤 Wilhelm Vogt
- 👤 Edgar Fischer
- 👤 Eberhard Auer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:18
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/10; C08F20/22; C08F8/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
91 words
IN A PROCESS FOR MAKING POLY-A-OXYACRYLIC ACID BY CONTACTING A SOLUTION OF A-CHLORACRYLIC ACID WITH RADICAL-YIELDING POLYMERIZATION CATALYST HEATING AND THEREBY HYDROLYZING THE RESULTING POLY-A-CHLORACRYLIC ACID IN AQUEOUS SLUTION WITH THE RESULTANT PRECIPITATION OF SOLID POLY-A-OXYACRYLIC ACID AND SEPARATING THE POLY-A-OXYACRYLIC ACID, THE IMPROVEMENT WHICH COMPRISES CONTACTING AN AQUEOUS A-CHLORACRYLIC ACID SOLUTION WITH THE RADICAL-YIELDING POLYMERIZATION CATALYST FOR A PERIOD OF AT LEAST 30 MINUTES AND, WHILE LEAVING THE RESULTING POLY-ACHLORACRYLIC ACID UNSEPARATED HEATING IT FOR A PERIOD OF AT LEAST 1 HOUR TO TEMPERATURE WITHIN THE RANGE 80* AND 110*C.
Claim 2
Dependent Claim
91 words
IN A PROCESS FOR MAKING POLY-A-OXYACRYLIC ACID BY CONTACTING A SOLUTION OF A-CHLORACRYLIC ACID WITH RADICAL-YIELDING POLYMERIZATION CATALYST HEATING AND THEREBY HYDROLYZING THE RESULTING POLY-A-CHLORACRYLIC ACID IN AQUEOUS SLUTION WITH THE RESULTANT PRECIPITATION OF SOLID POLY-A-OXYACRYLIC ACID AND SEPARATING THE POLY-A-OXYACRYLIC ACID, THE IMPROVEMENT WHICH COMPRISES CONTACTING AN AQUEOUS A-CHLORACRYLIC ACID SOLUTION WITH THE RADICAL-YIELDING POLYMERIZATION CATALYST FOR A PERIOD OF AT LEAST 30 MINUTES AND, WHILE LEAVING THE RESULTING POLY-ACHLORACRYLIC ACID UNSEPARATED HEATING IT FOR A PERIOD OF AT LEAST 1 HOUR TO TEMPERATURE WITHIN THE RANGE 80* AND 110*C.
Claim 3
Dependent Claim
19 words
A process as claimed in claim 1, wherein light rich in energy is used as the radical-yielding polymerization caTalyst.
Claim 4
Dependent Claim
50 words
A process as claimed in claim 1, wherein a substance selected from the group consisting of potassium peroxo-disulfate-(VI), sodium perborate, azo-bis-isobutyronitrile, benzoyl peroxide, dibenzoyl peroxide and cumene hydroperoxide is used as the radical-yielding polymerization catalyst in proportions within the range 0.1 and 12 weight percent, based on Alpha -chloracrylic acid.
Claim 5
Dependent Claim
42 words
A process as claimed in claim 1, wherein a redox system comprised of an oxidant and a reductant is used as the radical-yielding polymerization catalyst in a total proportion within the range 0.1 and 20 weight percent, based on Alpha -chloracrylic acid.
Claim 6
Dependent Claim
51 words
A process as claimed in claim 4, wherein the oxidant is a member selected from the group consisting of potassium peroxo-disulfate-(VI), sodium perborate, benzoyl peroxide, dibenzoyl peroxide and cumene hydroperoxide, and the reductant is a member selected from the group consisting of sodium dithionite, sodium sulfite, sodium thiosulfate and thioglycolic acid.
Claim 7
Dependent Claim
50 words
A process as claimed in claim 1, wherein the aqueous Alpha -chloracrylic acid solution is used in admixture with between 0.5 and 10 mol percent, based on Alpha -chloracrylic acid, of a member selected from the group consisting of thiols, allyl compounds and aliphatic halogen compounds as polymerization chain regulators.
Claim 8
Dependent Claim
26 words
A process as claimed in claim 1, wherein the aqueous Alpha -chloracrylic acid solution is used in admixture with hydrogen chloride as the polymerization chain regulator.
Claim 9
Dependent Claim
46 words
A process as claimed in claim 1, wherein the aqueous Alpha -chloracrylic acid solution is used in admixture with hydrogen chloride as the polymerization chain regulator, the solution subjected to polymerization being an Alpha -chloracrylic acid solution in aqueous 10 - 25 weight percent hydrochloric acid.
Claim 10
Dependent Claim
23 words
A process as claimed in claim 1, wherein the aqueous solution of Alpha -chloracrylic acid is vigorously stirred for at least 30 minutes.
Claim 11
Dependent Claim
31 words
A process as claimed in claim 1, wherein the aqueous Alpha -chloracrylic acid solution having radical-yielding polymerization catalysts dissolved therein is vigorously stirred for a period of at least 30 minutes.
Claim 12
Dependent Claim
47 words
A process as claimed in claim 1, wherein the aqueous Alpha -chloracrylic acid solution having a radical-yielding polymerization catalyst or a redox system dissolved therein or being exposed to the action of light rich in energy, is maintained at temperatures within the range 20* and 80* C.
Claim 13
Dependent Claim
37 words
A process as claimed in claim 1, wherein an aqueous Alpha -chloracrylic acid solution containing one of the radical-yielding polymerization catalysts as claimed in claim 3, is heated to temperatures within the range 80* and 110* C.
Claim 14
Dependent Claim
40 words
A process as claimed in claim 1, wherein the poly- Alpha -chloracrylic acid obtained in aqueous medium is left unisolated and vigorously stirred for a period of at least 1 hour at temperatures within the range 80* and 110* C.
Claim 15
Dependent Claim
42 words
A process as claimed in claim 1, wherein the poly- Alpha -oxyacrylic acid being obtained in solid form on heating the aqueous solution to temperatures within the range 80* and 110* C, is filtered off, scrubbed with water and dried under vacuum.
References Cited (Backward Citations)
US3352771A
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 |