US4217273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for azo pigments
Assignee: Wyeth Holdings LLC
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Filing: 1979-01-05
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Granted: 1980-08-12
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Expires: 1999-01-05
Abstract
Abstract A pigment modifier composition for azo pigments is prepared in situ by chlorination of 2-hydroxy-3-naphthoic acid with a hypochlorite such that up to 10% of the acid is converted into 1-chloro-2-hydroxy-3-naphthoic acid.
Inventors
- 👤 Isaiah Von
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:01
CPC Classifications
C; C09; C09B; C09B67/00; C09B67/0033; C09B67/0046; C09B67/0051; C09B29/00; C09B29/10; C09B29/103; C09B29/106; C09B63/00; C09B63/005
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
127 words
In a process for the preparation of an azo pigment whereby a diazo of an aromatic amino sulfonic acid is coupled into 2-hydroxy-3-naphthoic acid and whereby said pigment is optionally converted into the alkali metal, alkaline earth metal, or manganese salt thereof, the improvement which comprises: (1) forming an aqueous alkaline solution of 2-hydroxy-3-naphthoic acid, containing up to about a 20 percent molar excess over that amount stoichiometrically required to couple with said diazo com-(2) adding to said solution an amount of alkali metal hypochlorite to produce in situ 1-chloro-2-hydroxy-3-naphthoic acid, such that the amount thereof comprises from about 1 to 10 percent by weight, based on the total weight of 2-hydroxy-3-naphthoic acid and 1-chloro-2-hydroxy-3-naphthoic acid; and (3) adding thereto an aqueous solution of said diazo compound.
Claim 2
Dependent Claim
127 words
In a process for the preparation of an azo pigment whereby a diazo of an aromatic amino sulfonic acid is coupled into 2-hydroxy-3-naphthoic acid and whereby said pigment is optionally converted into the alkali metal, alkaline earth metal, or manganese salt thereof, the improvement which comprises: (1) forming an aqueous alkaline solution of 2-hydroxy-3-naphthoic acid, containing up to about a 20 percent molar excess over that amount stoichiometrically required to couple with said diazo com-(2) adding to said solution an amount of alkali metal hypochlorite to produce in situ 1-chloro-2-hydroxy-3-naphthoic acid, such that the amount thereof comprises from about 1 to 10 percent by weight, based on the total weight of 2-hydroxy-3-naphthoic acid and 1-chloro-2-hydroxy-3-naphthoic acid; and (3) adding thereto an aqueous solution of said diazo compound.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein the hypochlorite is sodium hypochlorite.
References Cited (Backward Citations)
US3520870A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-12 | 1984-02-11 | 1984-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-12 | 1988-02-11 | 1988-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-12 | 1992-02-11 | 1992-08-12 | $7700.00 | Window Closed / Lapsed |