Patent US2275396A successfully refreshed from Google Patents.
US4439240A
Expired / Lapsed
US
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Aqueous milling of quinacridone pigment
Assignee: BASF Corp
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Filing: 1983-02-16
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Granted: 1984-03-27
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Expires: 2003-02-16
Abstract
Abstract Pigmentary grade quinacridone pigments are prepared from crude quinacridone by dry milling the crude quinacridone to form aggregated low crystallinity material followed by milling the low crystallinity in water using steel shot as the milling elements. In a preferred aspect of the invention from 0.5 to 5 wt percent, based on quinacridone, of phthalimidomethylquinacridone is present in the water milling step. In another preferred aspect of the invention the water milled pigment is extracted with a dilute hot acid in the presence of naphthenic acids and then dried.
Inventors
- 👤 James B. Ganci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:34
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0017; C09B67/0022
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
45 words
A process comprising dry ball milling crude quinacridone to convert it to a highly agglomerated low crystallinity form, followed by milling the low crystallinity material with shot in water in the presence of a minor amount of base and recovering a pigmentary particle size pigment.
Claim 2
Dependent Claim
45 words
A process comprising dry ball milling crude quinacridone to convert it to a highly agglomerated low crystallinity form, followed by milling the low crystallinity material with shot in water in the presence of a minor amount of base and recovering a pigmentary particle size pigment.
Claim 3
Dependent Claim
24 words
The process of claim 1 wherein from 0.5 to 5 percent by weight phthalimidomethylquinacridone is comilled with the quinacridone in the water milling step.
Claim 4
Dependent Claim
11 words
The purpose of claim 2 wherein the quinacridone is gamma quinacridone.
Claim 5
Dependent Claim
19 words
The process of claim 3 wherein the water milled quinacridone is extracted with a hot dilute acid and dried.
Claim 6
Dependent Claim
32 words
The process of claim 4 wherein from 1 to 3 percent by weight based on quinacridone of naphthenic acid is added to the pigment prior to completion of the acid extraction step.
References Cited (Backward Citations)
US3752688A
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US4158572A
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US4094699A
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US4088506A
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US4260424A
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US4371642A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |