US4010180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the purification of copper phthalocyanine
Assignee: Hoechst AG
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Filing: 1973-12-21
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Granted: 1977-03-01
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Expires: 1993-12-21
Abstract
Abstract A process for the purification of optionally substituted crude phthalocyanines wherein a phthalocyanine is introduced into a 84 to 88 % sulfuric acid, the phthalocyanine sulfate formed is subjected to a crystal growth at 60 - 100° C in an inert gas atmosphere, the phthalocyanine sulfate is isolated and the phthalocyanine is recovered by hydrolysis with water. By this process a phthalocyanine sulfate is formed in a coarse crystalline form which can easily be filtered and which furtheron can easily be processed to a valuable pigment of the α-modification.
Inventors
- 👤 Siegfried Schiessler
- 👤 Ernst Spietschka
- 👤 Wolfgang Tronich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:56
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0017; C09B67/0019
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
88 words
In a process for purifying an unsubstituted or halogenated copper phthalocyanine by transforming it into its sulfate and recovering it by hydrolysis with water, the improvement comprising: introducing an unsubstituted or halogenated copper phthalocyanine into (1) a 4 to 10-fold amount of sulfuric acid of an initial strength of 84 to 88% by weight, or (2) a more concentrated sulfuric acid and diluting it to said concentration range, and heating the so-obtained copper phthalocyanine sulfate in an inert gas atmosphere to a temperature of 60° to 100° C.
Claim 2
Dependent Claim
88 words
In a process for purifying an unsubstituted or halogenated copper phthalocyanine by transforming it into its sulfate and recovering it by hydrolysis with water, the improvement comprising: introducing an unsubstituted or halogenated copper phthalocyanine into (1) a 4 to 10-fold amount of sulfuric acid of an initial strength of 84 to 88% by weight, or (2) a more concentrated sulfuric acid and diluting it to said concentration range, and heating the so-obtained copper phthalocyanine sulfate in an inert gas atmosphere to a temperature of 60° to 100° C.
Claim 3
Dependent Claim
35 words
A process as claimed in claim 1, wherein the phthalocyanine is dissolved first in concentrated sulfuric acid or oleum and then diluted by addition of water, to a sulfuric acid concentration of 84 to 88%.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 1, wherein the crude phthalocyanine is introduced into a 85.5 to 86.5% sulfuric acid.
Claim 5
Dependent Claim
23 words
A process as claimed in claim 1, wherein heating is continued until the viscosity of the copper phthalocyanine sulfate suspension is strongly reduced.
Claim 6
Dependent Claim
17 words
A process as claimed in claim 1, wherein the halogenated copper phthalocyanine is a chlorinated copper phthalocyanine.
Claim 7
Dependent Claim
18 words
A process as claimed in claim 5, wherein the chlorine content is up to about 6% by weight.
References Cited (Backward Citations)
US2284685A
Cited
US2365464A
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US2602800A
Cited
US2917518A
Cited
US3717493A
Cited
US3801591A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |