Patent US4098977A successfully refreshed from Google Patents.
US4098977A
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Method for preparing polymers from water soluble vinyl monomers
Assignee: Dow Chemical Co
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Filing: 1977-01-26
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Granted: 1978-07-04
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Expires: 1997-01-26
Abstract
Abstract A concentrated solution of a water-soluble vinyl monomer is mixed at or below room temperature with an effective amount of a peroxygen catalyst and the resulting solution is freed of inhibitory oxygen and thereafter atomized into a reaction vessel containing an atmosphere of gaseous sulfur dioxide to produce a polymer product by redox catalysis.
Inventors
- 👤 Maurice L. Zweigle
- 👤 Samuel J. Kasley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:05
CPC Classifications
C; C08; C08F; C08F4/00; C08F4/40; C08F2/00; C08F2/04; C08F2/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
80 words
A method for preparing a polymer from a water-soluble vinyl monomer which comprises forming a concentrated aqueous solution of said monomer containing a peroxygen catalyst, purging said solution until substantially free of inhibitory oxygen and spraying the purged solution at a temperature of from about 15° to about 30° C. into an atmosphere substantially free of oxygen and containing sulfur dioxide gas, said peroxygen catalyst and sulfur dioxide being present in amounts effective to catalyze polymerization of the vinyl monomer.
Claim 2
Independent Claim
80 words
A method for preparing a polymer from a water-soluble vinyl monomer which comprises forming a concentrated aqueous solution of said monomer containing a peroxygen catalyst, purging said solution until substantially free of inhibitory oxygen and spraying the purged solution at a temperature of from about 15° to about 30° C. into an atmosphere substantially free of oxygen and containing sulfur dioxide gas, said peroxygen catalyst and sulfur dioxide being present in amounts effective to catalyze polymerization of the vinyl monomer.
Claim 3
Dependent Claim
11 words
A method according to claim 1 wherein the monomer is acrylamide.
Claim 4
Dependent Claim
24 words
A method according to claim 2 wherein the monomer is employed in a concentration of from about 30 to about 60 percent by weight.
Claim 5
Dependent Claim
23 words
A method according to claim 1 wherein the monomer solution in droplet form is passed countercurrently through the atmosphere containing sulfur dioxide gas.
Claim 6
Dependent Claim
42 words
A method according to claim 3 wherein the monomer solution contains from about 100 to 1100 parts by weight of tertiary butyl hydroperoxide per million parts of acrylamide and the atmosphere contains at least about 1 percent by volume of sulfur dioxide.
References Cited (Backward Citations)
US3644305A
Cited
US4020256A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |