US4253839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the fine distribution of pigments of the dioxazine series
Assignee: Hoechst AG
•
Filing: 1978-09-20
•
Granted: 1981-03-03
•
Expires: 1998-09-20
Abstract
Abstract Coarsely crystalline crude dioxazine pigments are subjected to dry milling while maintaining their crystallinity as far as possible until the desired degree of fineness is reached and then treated with a solvent.
Inventors
- 👤 Ernst Spietschka
- 👤 Manfred Urban
- 👤 Erich Paulus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:27
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0014; C09B19/00; C09B19/02
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
A process for finely comminuting a dioxazine pigment which comprises introducing into a mill having a flexible lining a coarsely crystallized crude dioxazine pigment and a large amount of rotatable grinding bodies relative to the amount of pigment introduced, said grinding bodies making essentially rotating movements, dry milling the coarse pigment within the mill while substantially maintaining its crystallinity until the desired degree of fineness is obtained, so operating the mill that the grinding bodies mainly have a rotating movement and the transfer of kinetic energy thereto is minimized and subsequently mixing the ground pigment with a solvent to disaggregate it.
Claim 2
Dependent Claim
101 words
A process for finely comminuting a dioxazine pigment which comprises introducing into a mill having a flexible lining a coarsely crystallized crude dioxazine pigment and a large amount of rotatable grinding bodies relative to the amount of pigment introduced, said grinding bodies making essentially rotating movements, dry milling the coarse pigment within the mill while substantially maintaining its crystallinity until the desired degree of fineness is obtained, so operating the mill that the grinding bodies mainly have a rotating movement and the transfer of kinetic energy thereto is minimized and subsequently mixing the ground pigment with a solvent to disaggregate it.
Claim 3
Dependent Claim
15 words
A process as claimed in claim 1 wherein milling is performed in a vibrating mill.
Claim 4
Dependent Claim
22 words
A process as claimed in claim 1, wherein the grinding bodies have a surface as smooth and free of pores as possible.
Claim 5
Dependent Claim
15 words
A process as claimed in claim 1, wherein milling is performed without a grinding auxiliary.
Claim 6
Dependent Claim
22 words
A process as claimed in claim 1, wherein the desired degree of fineness is controlled by the X-ray pattern of the load.
Claim 7
Dependent Claim
21 words
A process according to claim 1 wherein the solvent is a volatile solvent which is removed from the pigment by distillation.
Claim 8
Dependent Claim
50 words
A process as claimed in claim 1, wherein the solvent is an aliphatic alcohol of 1 to 6 carbon atoms, a lower aliphatic ketone, a hydrocarbon, a halogenated hydrocarbon, a heterocyclic base, a N-(lower alkyl) or N,N-di-(lower alkyl) lower carboxylic acid amide, a carboxylic acid or a carboxylic acid ester.
Claim 9
Dependent Claim
26 words
A process as claimed in claim 7, wherein the solvent is a lower alkanol, acetone, chlorobenzene, ethyl acetate, pyridine, dimethyl formamide or a lower alkanoic acid.
Claim 10
Dependent Claim
12 words
A process as claimed in claim 1, wherein the solvent is isobutanol.
Claim 11
Dependent Claim
18 words
A process as claimed in claim 1, wherein the solvent treatment is performed in a weakly acidic medium.
Claim 12
Dependent Claim
20 words
A process as claimed in claim 1, wherein the solvent treatment is carried out in a neutral or alkaline medium.
Claim 13
Dependent Claim
18 words
A process as claimed in claim 1, wherein the solvent treatment is performed with addition of a surfactant.
Claim 14
Dependent Claim
23 words
A process according to claim 1 wherein the mixture of pigment and solid is heated to a temperature of up to 150° C.
Claim 15
Dependent Claim
108 words
A process for preparing a dioxazine pigment which comprises grinding Pigment Violet 23 in a vibration mill coated with plastic or rubber with a substantially larger amount of grinding bodies having a smooth surface free of pores, the grinding bodies making essentially rotating movements, until in the X-ray pattern with Cu K.sub.α -rays the quotient of the height of the peak at 5.2°θ and the median height of the noise level is in the range of 5 to 6.6, and thereafter treating the milled pigment in a solvent selected from lower alkanol, di-(lower alkyl) ketone, lower alkanoic acid, lower alkanoic acid lower alkyl ester, chlorobenzene, dimethylformamide and pyridine.
Claim 16
Dependent Claim
108 words
A process for preparing a dioxazine pigment which comprises grinding Pigment Violet 23 in a vibration mill coated with plastic or rubber with a substantially larger amount of grinding bodies having a smooth surface free of pores, the grinding bodies making essentially rotating movements, until in the X-ray pattern with Cu K.sub.α -rays the quotient of the height of the peak at 5.2°θ and the median height of the noise level is in the range of 5 to 6.6, and thereafter treating the milled pigment in a solvent selected from lower alkanol, di-(lower alkyl) ketone, lower alkanoic acid, lower alkanoic acid lower alkyl ester, chlorobenzene, dimethylformamide and pyridine.
Claim 17
Dependent Claim
10 words
Pigment obtained by the process as claimed in claim 14.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |