US4431806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of pigments of the perylene-3,4,9,10-tetracarboxylic acid diimide series, and their use
Assignee: Hoechst AG
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Filing: 1981-05-08
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Granted: 1984-02-14
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Expires: 2001-05-08
Abstract
Abstract Very pure, transparent pigments of high color strength, of the formula ##STR1## in which R is hydrogen or alkyl having 1 to 4 C atoms, X is chlorine and/or bromine and n is a number from 0 to 4 are obtained by converting the corresponding crude pigment to the sulfate, isolating the sulfate, liberating the pure product from the sulfate by hydrolysis, separating off the pure product and dry milling the anhydrous material, with or without additives and with or without subsequent solvent finishing. These pigments are suitable for coloring paints and plastic compositions, especially for pigmenting metallic paints.
Inventors
- 👤 Ernst Spietschka
- 👤 Manfred Urban
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:30
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0017; C09B67/0002
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
93 words
A process for the preparation of a perylene-3,4,9,10-tetracarboxylic acid diimide pigment of the formula ##STR3## in which R is hydrogen or alkyl of from 1 to 4 carbon atoms, X is chlorine and/or bromine and n is a number of from 0 to 4, which comprises converting the corresponding crude pigment to its sulfate, isolating the sulfate, hydrolyzing the sulfate to liberate therefrom the pure pigment, separating off the pure pigment, and dry-milling the pure pigment, in its anhydrous state, with or without one or more solid additives and with subsequent solvent finishing.
Claim 2
Dependent Claim
93 words
A process for the preparation of a perylene-3,4,9,10-tetracarboxylic acid diimide pigment of the formula ##STR3## in which R is hydrogen or alkyl of from 1 to 4 carbon atoms, X is chlorine and/or bromine and n is a number of from 0 to 4, which comprises converting the corresponding crude pigment to its sulfate, isolating the sulfate, hydrolyzing the sulfate to liberate therefrom the pure pigment, separating off the pure pigment, and dry-milling the pure pigment, in its anhydrous state, with or without one or more solid additives and with subsequent solvent finishing.
Claim 3
Dependent Claim
23 words
A process as claimed in claim 1, wherein the additive is a milling assistant which after working up can remain in the pigment.
Claim 4
Dependent Claim
14 words
A process as claimed in claim 1, wherein the additive is a surface-active substance.
Claim 5
Dependent Claim
21 words
A process as claimed in claim 3, wherein the additive is a fatty acid salt, a resin or a resin salt.
Claim 6
Dependent Claim
18 words
A process as claimed in claim 1, wherein the solvent finishing is carried out with a polar solvent.
Claim 7
Dependent Claim
21 words
A process as claimed in claim 1 or 5, wherein the solvent finishing is carried out with a polar organic solvent.
Claim 8
Dependent Claim
19 words
A process as claimed in claim 6, wherein the solvent finishing is carried out with N-methylpyrrolidone, dimethylformamide or nitrobenzene.
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) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |