US2941989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alpha-methylstyrene resin preparation
Assignee: American Oil Co
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Filing: 1956-11-27
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Granted: 1960-06-21
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Expires: 1976-11-27
Abstract
No abstract record available.
Inventors
- 👤 Fred A Ford
- 👤 Paul D May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:25
CPC Classifications
C; C08; C08F; C08F12/00; C08F12/02; C08F12/04; C08F12/06; C08F12/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
171 words
IN A CONTINUOUS, HOMOGENEOUS POLYMERIZATION PROCESS FOR THE PREPARATION OF AN ALPHA-METHYLSTYRENE RESIN HAVING A WEIGHT AVERAGE MOLECULAR WEIGHT IN THE RANGE OF ABOUT 700 TO ABOUT 2,000 ESPECIALLY SUITABLE FOR FLOOR TILE MANUFACTURE, THE STEPS OF FLOWING A SUBSTANTIALLY ANHYDROUS SOLUTION OF ALPHA-METHYLSTYRENE IN A CONCENTRATION BETWEEN ABOUT 30 AND ABOUT 40 WEIGHT PERCENT IN AN INERT AROMATIC HYDROCARBON SOLVENT THROUGH A POLYMERIZATION REACTOR AT A REACTION TEMPERATURE BETWEEN ABOUT -20*C. AND ABOUT -40*C. IN CONTACT WITH BF3 DISSOLVED IN SAID SOLVENT IN A CONCENTRATION BETWEEN ABOUT 0.25 AND ABOUT 1 WEIGHT PERCENT, BASED ON ALPHA-METHYLSTYRENE, UNDER A BF3 PARTIAL PRESSURE OF AT LEAST ABOUT 50 P.S.I.G. AND SUFFICIENT TO MAINTAIN SAID DISSOLVED BF3 CONCENTRATION IN SAID SOLVENT, EFFECTING POLYMERIZATION OF SAID ALPHA-METHYLSTYRENE WHILE WITHDRAWING THE HEAT GENERATED BY SAID POLYMERIZATION AT A RATE SUFFICIENT TO MAINTAIN SAID REACTION TEMPERATURE, CONTUNING SAID POLYMERIZATION FOR A PERIOD BETWEEN ABOUT 2 AND ABOUT 60 MINUTES SUFFICIENT TO POLYMERIZE SAID ALPHA-METHYLSTYRENE QUANTITATIVELY AND WITHDRAWING THE HOMOGENEOUS SOLUTION THUS PRODUCED THROUGH A PRESSURE-REDUCING ZONE.
Claim 2
Dependent Claim
171 words
IN A CONTINUOUS, HOMOGENEOUS POLYMERIZATION PROCESS FOR THE PREPARATION OF AN ALPHA-METHYLSTYRENE RESIN HAVING A WEIGHT AVERAGE MOLECULAR WEIGHT IN THE RANGE OF ABOUT 700 TO ABOUT 2,000 ESPECIALLY SUITABLE FOR FLOOR TILE MANUFACTURE, THE STEPS OF FLOWING A SUBSTANTIALLY ANHYDROUS SOLUTION OF ALPHA-METHYLSTYRENE IN A CONCENTRATION BETWEEN ABOUT 30 AND ABOUT 40 WEIGHT PERCENT IN AN INERT AROMATIC HYDROCARBON SOLVENT THROUGH A POLYMERIZATION REACTOR AT A REACTION TEMPERATURE BETWEEN ABOUT -20*C. AND ABOUT -40*C. IN CONTACT WITH BF3 DISSOLVED IN SAID SOLVENT IN A CONCENTRATION BETWEEN ABOUT 0.25 AND ABOUT 1 WEIGHT PERCENT, BASED ON ALPHA-METHYLSTYRENE, UNDER A BF3 PARTIAL PRESSURE OF AT LEAST ABOUT 50 P.S.I.G. AND SUFFICIENT TO MAINTAIN SAID DISSOLVED BF3 CONCENTRATION IN SAID SOLVENT, EFFECTING POLYMERIZATION OF SAID ALPHA-METHYLSTYRENE WHILE WITHDRAWING THE HEAT GENERATED BY SAID POLYMERIZATION AT A RATE SUFFICIENT TO MAINTAIN SAID REACTION TEMPERATURE, CONTUNING SAID POLYMERIZATION FOR A PERIOD BETWEEN ABOUT 2 AND ABOUT 60 MINUTES SUFFICIENT TO POLYMERIZE SAID ALPHA-METHYLSTYRENE QUANTITATIVELY AND WITHDRAWING THE HOMOGENEOUS SOLUTION THUS PRODUCED THROUGH A PRESSURE-REDUCING ZONE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-06-21 | 1963-12-21 | 1964-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-21 | 1967-12-21 | 1968-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-21 | 1971-12-21 | 1972-06-21 | $7700.00 | Window Closed / Lapsed |