US5115055A
Expired / Lapsed
US
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Hydroperoxide catalyzed free radical polymerization of vinyl aromatic monomers
Assignee: Dow Chemical Co
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Filing: 1991-10-29
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Granted: 1992-05-19
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Expires: 2011-10-29
Abstract
Abstract High molecular weight polymers of vinyl aromatic monomers are prepared by organic hydroperoxide initiated free radical polymerization in the presence of 5 to 5000 ppm of a soluble organic acid having pKa from 0.5 to 2.5.
Inventors
- 👤 Virginia A. Dais
- 👤 Duane B. Priddy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:20
CPC Classifications
C; C08; C08F; C08F12/00; C08F12/02; C08F12/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
52 words
A process for free radical polymerization of styrene to prepare high molecular weight polystyrene characterized in that the polymerization is conducted in the presence of from 5 to 5,000 ppm of a soluble organic acid having pKa from 0.5 to 2.5° C. and from 50 to 2000 ppm of an organic hydroperoxide.
Claim 2
Dependent Claim
52 words
A process for free radical polymerization of styrene to prepare high molecular weight polystyrene characterized in that the polymerization is conducted in the presence of from 5 to 5,000 ppm of a soluble organic acid having pKa from 0.5 to 2.5° C. and from 50 to 2000 ppm of an organic hydroperoxide.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the organic acid is methane-sulfonic acid.
Claim 4
Dependent Claim
13 words
A process according to claim 1 wherein the organic acid is camphorsulfonic acid.
Claim 5
Dependent Claim
16 words
A process according to claim 1 wherein the polystyrene has a Mw from 100,000 to 1,000,000.
References Cited (Backward Citations)
US2971939A
Cited
US4772671A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-19 | 1995-11-18 | 1996-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-19 | 1999-11-18 | 2000-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-19 | 2003-11-18 | 2004-05-19 | $7700.00 | Window Closed / Lapsed |