Patent US4088506A successfully refreshed from Google Patents.
US4088506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing pigmentary quinacridone using low-salt milling
Assignee: Novartis Corp
•
Filing: 1977-04-15
•
Granted: 1978-05-09
•
Expires: 1997-04-15
Abstract
Abstract Process for converting crude quinacridone to pigmentary form by milling crude quinacridone in the presence of from 5% to 50% by weight of aluminum sulfate, based on the weight of the crude quinacridone. The resulting quinacridone exhibits high masstone transparency in coating compositions.
Inventors
- 👤 Roland H. Wetzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:37
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0001; C09B67/0002
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
63 words
In a process for converting crude quinacridone to pigmentary form by dry milling the crude quinacridone, contacting the milled quinacridone with an organic liquid in water emulsion, and recovering the quinacridone in pigmentary form, the improvement comprising dry milling the crude quinacridone in the presence of from 5% to 50% by weight of aluminum sulfate, based on the weight of the crude quinacridone.
Claim 2
Dependent Claim
63 words
In a process for converting crude quinacridone to pigmentary form by dry milling the crude quinacridone, contacting the milled quinacridone with an organic liquid in water emulsion, and recovering the quinacridone in pigmentary form, the improvement comprising dry milling the crude quinacridone in the presence of from 5% to 50% by weight of aluminum sulfate, based on the weight of the crude quinacridone.
Claim 3
Dependent Claim
34 words
Process for converting crude quinacridone to pigmentary form according to claim 1 wherein the aluminum sulfate is in an amount from 10% to 4% by weight, based on the weight of the crude quinacridone.
Claim 4
Dependent Claim
18 words
Process for converting crude quinacridone to pigmentary form according to claim 2 wherein the aluminum sulfate is hydrated.
References Cited (Backward Citations)
US3030370A
Cited
US3980488A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |