Patent US4804417A successfully refreshed from Google Patents.
US4804417A
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Process for producing dioxazine violet pigment
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1987-12-01
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Granted: 1989-02-14
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Expires: 2007-12-01
Abstract
Abstract Dioxazine violet pigment clear in color hue, high in tinting strength and good in dispersibility, which is suitable for ink, is prepared by treating a crude dioxazine violet with sulfuric acid (to finer it) and then treating an aqueous suspension of the resulting dioxazine violet in coexistence of an alcohol and an inorganic salt.
Inventors
- 👤 Taira Fujita
- 👤 Yoshiaki Hayashi
- 👤 Hiroshi Okayasu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:59
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0014; C09B67/0017
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
52 words
A process for producing dioxazine violet pigment which comprises treating a crude dioxazine violet with sulfuric acid until it is completely converted to the sulfate and then hydrolyzing the sulfate to finer particles thereof and then treating an aqueous suspension of the resulting particles with both an alcohol and an inorganic salt.
Claim 2
Dependent Claim
52 words
A process for producing dioxazine violet pigment which comprises treating a crude dioxazine violet with sulfuric acid until it is completely converted to the sulfate and then hydrolyzing the sulfate to finer particles thereof and then treating an aqueous suspension of the resulting particles with both an alcohol and an inorganic salt.
Claim 3
Dependent Claim
26 words
A process according to claim 1 wherein an amount of water in the aqueous suspension is 2-40 times as much as the weight of the pigment.
Claim 4
Dependent Claim
22 words
A process according to claim 2 wherein an amount of water is 5-20 times as much as the weight of the pigment.
Claim 5
Dependent Claim
24 words
A process according to claim 1 wherein an amount of the inorganic salt in the aqueous suspension is 0.1-25% by weight of water used.
Claim 6
Dependent Claim
19 words
A process according to claim 4 wherein an amount of the inorganic salt is 1-20% by weight of water.
Claim 7
Dependent Claim
25 words
A process according to claim 1 wherein an amount of alcohol is 0.1-5.0 times as much as the weight of pigment in terms of solid.
Claim 8
Dependent Claim
25 words
A process according to claim 6 wherein an amount of alcohol is 0.5-2.0 times as much as the weight of pigment in terms of solid.
Claim 9
Dependent Claim
30 words
A process according to claim 1 wherein a treatment of an aqueous suspension in the presence of both alcohol and inorganic salt is effected at 0°-120° C. for 0.1-20 hours.
Claim 10
Dependent Claim
17 words
A process according to claim 8 wherein the treatment is effected at 10°-90° C. for 1-10 hours.
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) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |