US4017496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing pigmentary quinacridone in predetermined crystal form
Assignee: Novartis Corp
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Filing: 1975-11-21
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Granted: 1977-04-12
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Expires: 1995-11-21
Abstract
Abstract Process for preparing pigmentary quinacridone in the α-, β-, and γ-form by vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 550° C. at from 10.sup. -3 mmHg to 10.sup. -5 mmHg, rapidly condensing the evaporated crude quinacridone to form an amorphous condensate and contacting the amorphous condensate with o-dichlorobenzene or dimethylformamide to form pigmentary quinacridone. This process eliminates the need for acid pasting, salt milling, and solvent milling conventionally used to produce pigmentary quinacridone.
Inventors
- 👤 Albert Robert Hanke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:42
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0025; C09B67/0027; C09B48/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
80 words
Process for preparing pigmentary quinacridone in the α-form by the steps of i. vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 500° C. in a high vacuum of from 10.sup. -3 mmHg to 10.sup. -5 mmHg, ii. rapidly condensing the evaporated crude quinacridone on a substrate at a temperature of less than 40° C. to form an amorphous condensate, and iii. contacting the condensate with o-dichlorobenzene at room temperature to form pigmentary quinacridone in the α-form.
Claim 2
Dependent Claim
80 words
Process for preparing pigmentary quinacridone in the α-form by the steps of i. vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 500° C. in a high vacuum of from 10.sup. -3 mmHg to 10.sup. -5 mmHg, ii. rapidly condensing the evaporated crude quinacridone on a substrate at a temperature of less than 40° C. to form an amorphous condensate, and iii. contacting the condensate with o-dichlorobenzene at room temperature to form pigmentary quinacridone in the α-form.
Claim 3
Dependent Claim
78 words
Process for preparing pigmentary quinacridone in the β-form by the steps of i. vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 500° C. in a high vacuum of from 10.sup. -3 mmHg to 10.sup. -5 mmHg, ii. rapidly condensing the evaporated crude quinacridone on a substrate at a temperature of less than 40° C. to form an amorphous condensate, and iii. contacting the condensate with boiling o-dichlorobenzene to form pigmentary quinacridone in the β-form.
Claim 4
Dependent Claim
78 words
Process for preparing pigmentary quinacridone in the β-form by the steps of i. vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 500° C. in a high vacuum of from 10.sup. -3 mmHg to 10.sup. -5 mmHg, ii. rapidly condensing the evaporated crude quinacridone on a substrate at a temperature of less than 40° C. to form an amorphous condensate, and iii. contacting the condensate with boiling o-dichlorobenzene to form pigmentary quinacridone in the β-form.
Claim 5
Dependent Claim
80 words
Process for preparing pigmentary quinacridone in the γ-form by the steps of i. vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 500° C. in a high vacuum of from 10.sup. -3 mmHg to 10.sup. -5 mmHg, ii. rapidly condensing the evaporated crude quinacridone on a substrate at a temperature of less than 40° C. to form an amorphous condensate, and iii. contacting the condensate with dimethylformamide at room temperature to form pigmentary quinacridone in the γ-form.
Claim 6
Dependent Claim
80 words
Process for preparing pigmentary quinacridone in the γ-form by the steps of i. vacuum evaporating crude quinacridone at an elevated temperature from 400° C. to 500° C. in a high vacuum of from 10.sup. -3 mmHg to 10.sup. -5 mmHg, ii. rapidly condensing the evaporated crude quinacridone on a substrate at a temperature of less than 40° C. to form an amorphous condensate, and iii. contacting the condensate with dimethylformamide at room temperature to form pigmentary quinacridone in the γ-form.
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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |