US3715383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of tetrabromophthalic anhydride
Assignee: Individual
•
Filing: 1970-01-29
•
Granted: 1973-02-06
•
Expires: 1990-01-29
Abstract
Abstract A process for removing sulfate ions from crude tetrabromophthalic anhydride by dissolving it in an alcohol and then contacting the resultant solution with an anion exchanger.
Inventors
- 👤 H Praetzel
- 👤 E Neukirchen
- 👤 H Jenkner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:46
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/77; C07D307/87; C07D307/89; C07C; C07C51/00; C07C51/54; C07C51/573; C07C69/00; C07C69/76
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
82 words
A process for removing sulfate ions from crude tetrabromophthalic anhydride containing such ions said process comprising: I. forming the monoester of tetrabromophthalic acid by dissolving the crude tetrabromophthalic anhydride in a monohydric alcohol having from one to 12 carbon atoms or in a polyhydric alcohol having at least one secondary hydroxyl group and having one and only one primary hydroxyl group to form a solution and then II. contacting said solution with an anion exchanger in order to remove the sulfate ions.
Claim 2
Dependent Claim
82 words
A process for removing sulfate ions from crude tetrabromophthalic anhydride containing such ions said process comprising: I. forming the monoester of tetrabromophthalic acid by dissolving the crude tetrabromophthalic anhydride in a monohydric alcohol having from one to 12 carbon atoms or in a polyhydric alcohol having at least one secondary hydroxyl group and having one and only one primary hydroxyl group to form a solution and then II. contacting said solution with an anion exchanger in order to remove the sulfate ions.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein said monohydric alcohol is a primary alcohol of the formula: HOCnH2n 1 wherein n is an integer from 1 to 12 inclusive.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said crude tetrabromophthalic anhydride is dissolved in 1,2-propanediol to form said solution.
Claim 5
Dependent Claim
11 words
The process of claim 2 wherein said primary alcohol is methanol.
Claim 6
Dependent Claim
25 words
The process of claim 4 wherein said methanol and tetrabromophthalic anhydride are present in said solution in a molar ratio of from 2:1 to 100:1.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein the dissolving is conducted at a temperature between 20*C and the boiling point of the alcohol.
Claim 8
Dependent Claim
21 words
The process of claim 1 wherein the molar ratio of tetrabromophthalic anhydride to alcohol is equal to or greater than 1:1.
Claim 9
Dependent Claim
18 words
The process of claim 1 wherein the polyhydric alcohol has a normal boiling point of at least 120*C.
Claim 10
Dependent Claim
25 words
The process of claim 1 wherein the anion exchanger is a high polymer resin having as active groups nitrogen atoms which are reactive as bases.
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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |