Patent US4020256A successfully refreshed from Google Patents.
US4020256A
Expired / Lapsed
US
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Method for preparing polymers from water soluble vinyl monomers
Assignee: Dow Chemical Co
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Filing: 1975-07-03
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Granted: 1977-04-26
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Expires: 1995-07-03
Abstract
Abstract A concentrated solution of a water-soluble vinyl monomer is mixed at or below room temperature with an effective amount of a peroxide 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
2026-10-25 11:11
CPC Classifications
C; C08; C08F; C08F4/00; C08F4/40; C08F2/00; C08F2/04; C08F2/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
84 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 peroxide catalyst in the amount of from about 50 to 500 parts by weight per million parts of vinyl monomer, 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 a catalytic amount of sulfur dioxide gas.
Claim 2
Independent Claim
84 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 peroxide catalyst in the amount of from about 50 to 500 parts by weight per million parts of vinyl monomer, 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 a catalytic amount of sulfur dioxide gas.
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 50 to 500 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)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |