US4085133A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of monoperoxyphthalic acid
Assignee: PPG Industries Inc
•
Filing: 1976-11-24
•
Granted: 1978-04-18
•
Expires: 1996-11-24
Abstract
Abstract Stable monoperoxyphthalic acid is prepared by reacting phthalic anhydride with a stoichiometric excess of concentrated hydrogen peroxide in the absence of basic catalyst in liquid halogenated hydrocarbon medium in which the monoperoxyphthalic acid product is insoluble.
Inventors
- 👤 Robert G. Briody
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:11
CPC Classifications
C; C07; C07C; C07C407/00; C07C407/003; C08; C08G; C08G2120/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
A process for preparing thermally stable, solid monoperoxyphthalic acid comprising reacting, in a liquid halogenated hydrocarbon reaction medium, phthalic anhydride with an aqueous hydrogen peroxide solution having a hydrogen peroxide content of at least 65 percent by weight at a molar ratio of hydrogen peroxide to phthalic anhydride of at least 1.2 to 1, said liquid halogenated hydrocarbon being a solvent for the phthalic anhydride and a non-solvent for the monoperoxyphthalic acid, precipitating monoperoxyphthalic acid and recovering a solid monoperoxyphthalic acid having a decomposition rate of less than 3.0 weight percent per day at 60° C., said reaction being conducted with agitation at a temperature of between 35° C. and 70° C., in the absence of a basic catalyst and in the absence of the addition of acids or bases after completion of the reaction.
Claim 2
Dependent Claim
135 words
A process for preparing thermally stable, solid monoperoxyphthalic acid comprising reacting, in a liquid halogenated hydrocarbon reaction medium, phthalic anhydride with an aqueous hydrogen peroxide solution having a hydrogen peroxide content of at least 65 percent by weight at a molar ratio of hydrogen peroxide to phthalic anhydride of at least 1.2 to 1, said liquid halogenated hydrocarbon being a solvent for the phthalic anhydride and a non-solvent for the monoperoxyphthalic acid, precipitating monoperoxyphthalic acid and recovering a solid monoperoxyphthalic acid having a decomposition rate of less than 3.0 weight percent per day at 60° C., said reaction being conducted with agitation at a temperature of between 35° C. and 70° C., in the absence of a basic catalyst and in the absence of the addition of acids or bases after completion of the reaction.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein the halogenated hydrocarbon is ethylene dichloride.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein the molar ratio of hydrogen peroxide to phthalic anhydride is at least 1.6 to 1.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein the hydrogen peroxide solution has a hydrogen peroxide content of over 85 weight percent.
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) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |