Patent US2267426A successfully refreshed from Google Patents.
Patent US3328374A successfully refreshed from Google Patents.
US3328374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the suspension polymerization of styrene
Assignee: Dow Chemical Co
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Filing: 1965-03-01
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Granted: 1967-06-27
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Expires: 1985-03-01
Abstract
No abstract record available.
Inventors
- 👤 Clifford P Ronden
- 👤 Yu John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:57
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/12; C08F2/16; C08F2/18; C08F12/00; C08F12/02; C08F12/04; C08F12/06; C08F12/08; Y; Y10; Y10S; Y10S526/00; Y10S526/909; Y10S526/91
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
188 words
A PROCESS FOR POLYMERIZATION OF STYRENE MONOMERS TO PRODUCE POLYMERS IN THE FORM OF BEADS PREDOMINANTLY IN THE SIZE RANGE OF 590-2000 MICRONS, COMPRISING PREPARING AN INITIAL AQUEOUS SUSPENSION BY MIXING, AT A TEMPERATURE OF AT LEAST 40*C., WATER, THE STYRENE MONOMER TO BE POLYMERIZED, A THIXOTROPIC PASTE CONSISTING OF WATER AND A SUBSTANTIALLY WATER-INSOLUBLE INORGANIC FINELY PARTICULATE SUSPENSION STABILIZING AGENT, A SURFACE ACTIVE AGENT, AND A PROTECTIVE COLLOID; AND EFFECTING POLYMERIZATION OF SAID MONOMER BY COMBINED THERMAL AND CATALYTIC ACTION WHILE MAINTAINING THE PH OF THE SUSPENSION ABOVE 5.9; SAID PASTE HAVING A STABILIZING AGENT-TO-WATER WEIGHT RATIO OF 1:2-2:1 AND ON INITIAL AVERAGE PARTICLE SIZE OF ABOUT 0.5 MICRON, THE PROPORTION OF SAID INORGANIC SUSPENSION STABILIZING AGENT EMPLOYED AMOUNTING TO 0.102.00% OF THE WEIGHT OF SAID MONOMER; SAID SURFACE ACTIVE AGENT BEING SELECTED FROM THE GROUP CONSISTING OF THE SULFONATE SURFACE ACTIVE AGENTS AND AMPHOTERIC SURFACE ACTIVE AGENTS CONTAINING BOTH CARBOXYL AND AMINO FUNCTIONAL GROUPS, THE PROPORTION THEREOF AMOUNTING TO 0.012.00% OF THE TOTAL WEIGHT OF THE SUSPENSION; SAID PROTECTIVE COLLOID BEING EMPLOYED IN AN AMOUNT EQUAL TO 0.0001- 0.005% OF THE TOTAL WEIGHT OF THE SUSPENSION.
Claim 2
Dependent Claim
188 words
A PROCESS FOR POLYMERIZATION OF STYRENE MONOMERS TO PRODUCE POLYMERS IN THE FORM OF BEADS PREDOMINANTLY IN THE SIZE RANGE OF 590-2000 MICRONS, COMPRISING PREPARING AN INITIAL AQUEOUS SUSPENSION BY MIXING, AT A TEMPERATURE OF AT LEAST 40*C., WATER, THE STYRENE MONOMER TO BE POLYMERIZED, A THIXOTROPIC PASTE CONSISTING OF WATER AND A SUBSTANTIALLY WATER-INSOLUBLE INORGANIC FINELY PARTICULATE SUSPENSION STABILIZING AGENT, A SURFACE ACTIVE AGENT, AND A PROTECTIVE COLLOID; AND EFFECTING POLYMERIZATION OF SAID MONOMER BY COMBINED THERMAL AND CATALYTIC ACTION WHILE MAINTAINING THE PH OF THE SUSPENSION ABOVE 5.9; SAID PASTE HAVING A STABILIZING AGENT-TO-WATER WEIGHT RATIO OF 1:2-2:1 AND ON INITIAL AVERAGE PARTICLE SIZE OF ABOUT 0.5 MICRON, THE PROPORTION OF SAID INORGANIC SUSPENSION STABILIZING AGENT EMPLOYED AMOUNTING TO 0.102.00% OF THE WEIGHT OF SAID MONOMER; SAID SURFACE ACTIVE AGENT BEING SELECTED FROM THE GROUP CONSISTING OF THE SULFONATE SURFACE ACTIVE AGENTS AND AMPHOTERIC SURFACE ACTIVE AGENTS CONTAINING BOTH CARBOXYL AND AMINO FUNCTIONAL GROUPS, THE PROPORTION THEREOF AMOUNTING TO 0.012.00% OF THE TOTAL WEIGHT OF THE SUSPENSION; SAID PROTECTIVE COLLOID BEING EMPLOYED IN AN AMOUNT EQUAL TO 0.0001- 0.005% OF THE TOTAL WEIGHT OF THE SUSPENSION.
References Cited (Backward Citations)
US2594913A
Cited
US3243419A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-06-26 | 1970-12-26 | 1971-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-06-26 | 1974-12-26 | 1975-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-06-26 | 1978-12-26 | 1979-06-27 | $7700.00 | Window Closed / Lapsed |