US3919258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved process for making polymaleic anhydride
Assignee: FMC Technologies Ltd
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Filing: 1974-02-14
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Granted: 1975-11-11
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Expires: 1994-02-14
Abstract
Abstract A process for the manufacture of polymaleic anhydride which comprises polymerising maleic anhydride in xylene as solvent, the ortho-isomer content of the xylene being up to 99%, and using ditertiary butyl peroxide as polymerisation catalyst to give good yields and liquid products which can be easily separated.
Inventors
- 👤 Norman Richardson
- 👤 Thomas Ivor Jones
- 👤 Peter Miles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:04
CPC Classifications
C; C08; C08F; C08F22/00; C08F22/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
AN IMPROVED PROCESS FOR MANUFACTURING POLYMALEIC ANHYDRIDE WHEREIN MALEIC ANHYDRIDE DISSOLVED IN A WEIGHT RATIO OF 1:1 TO 1:3 IN XYLENE SOLVENT CONTAINING UP TO 99%ORTHOISOMER IS POLYMERIZED USING DI-TERT-BUTYL PEROXIDE POLYMERIZAATION CATALYST, SAID CATALYST BEING ADDED TO THE REACTION MIXTURE OVER APERIOD OF UP TO 2.5 HOURS, WHEREIN THE IMPROVEMENT COMPRISES USING 15 TO 40% BY WEIGHT OF DI-TERT-BUTYL PEROXIDE CATALYST BASED ON THE MALERIC ANHYDRIDE, CARRYING OUT THE POLYMERIZATION AT A TEMPERATURE OF 120* TO 145*C, AND ISOLATING AT A TEMPERATURE OVER 65*C ESSENTIALLY PURE POLYNALEIC ANHYDRIDE AS A LIGHT COLORED LIQUID IMMISCIBLE IN THE XYLENE LAYER WHICH CONTAINS UNREACTED MALEIC ANHYDRIDE AND REACTION BYPRODUCTS.
Claim 2
Dependent Claim
107 words
AN IMPROVED PROCESS FOR MANUFACTURING POLYMALEIC ANHYDRIDE WHEREIN MALEIC ANHYDRIDE DISSOLVED IN A WEIGHT RATIO OF 1:1 TO 1:3 IN XYLENE SOLVENT CONTAINING UP TO 99%ORTHOISOMER IS POLYMERIZED USING DI-TERT-BUTYL PEROXIDE POLYMERIZAATION CATALYST, SAID CATALYST BEING ADDED TO THE REACTION MIXTURE OVER APERIOD OF UP TO 2.5 HOURS, WHEREIN THE IMPROVEMENT COMPRISES USING 15 TO 40% BY WEIGHT OF DI-TERT-BUTYL PEROXIDE CATALYST BASED ON THE MALERIC ANHYDRIDE, CARRYING OUT THE POLYMERIZATION AT A TEMPERATURE OF 120* TO 145*C, AND ISOLATING AT A TEMPERATURE OVER 65*C ESSENTIALLY PURE POLYNALEIC ANHYDRIDE AS A LIGHT COLORED LIQUID IMMISCIBLE IN THE XYLENE LAYER WHICH CONTAINS UNREACTED MALEIC ANHYDRIDE AND REACTION BYPRODUCTS.
Claim 3
Dependent Claim
27 words
A process as claimed in claim 1 in which the amount of di-tertiary butyl peroxide is from 20 to 35% by weight based on the maleic anhydride.
Claim 4
Dependent Claim
23 words
A process as claimed in claim 1 in which the polymerisation reaction is carried out at a temperature of from 130*C to 145*C.
Claim 5
Dependent Claim
20 words
A process as claimed in claim 1 in which the ortho-isomer content of the xylene is from 1 to 25%.
References Cited (Backward Citations)
GB1063036A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |