Claims
- 1. A process for preparation of disulfonic acid intermediates of 4,4'-diamino-1,1'-dianthraquinonyl red pigments from a crude 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid or salt thereof, which comprises mixing an inorganic salt with an aqueous solution containing the crude disulphonic acid or the salt thereof to effect salting-out, the aqueous solution being adjusted to an acidic pH after or before the mixing.
- 2. The process according to claim 1, wherein the inorganic salt is used in an amount of about 1 to 5% by weight based on the weight of the aqueous solution.
- 3. The process according to claim 1, wherein the inorganic salt is selected from alkali metal salts and alkaline earth metal salts.
- 4. The process according to claim 1, wherein the inorganic salt is selected from sodium chloride, sodium sulfate and a mixture thereof.
- 5. The process according to claim 1, wherein concentration of the 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid or the salt thereof in the aqueous solution ranges from about 4 to 7% by weight based on the weight of the aqueous solution.
- 6. The process according to claim 1, wherein the mixing of the inorganic salt with the aqueous solution is carried out at a temperature of 70.degree. to 100.degree. C.
- 7. The process according to claim 1, wherein the aqueous solution is adjusted to a pH ranging from about 1 to 5 after or before the mixing.
- 8. The process according to claim 1, wherein the aqueous solution is adjusted to a pH ranging from about 1 to 5, and then the mixing of the inorganic salt with the aqueous solution is carried out.
- 9. The process according to claim 1, wherein the mixing of the inorganic salt with the aqueous solution is carried out at a temperature of 70.degree. to 100.degree. C., and then the mixture is kept at a temperature of 20.degree. to 60.degree. C. to effect the salting-out.
- 10. The process according to claim 1, wherein the aqueous solution is prepared by allowing a 1-amino-4-halogenoanthraquinone-2-sulfonic acid or a salt thereof to react in the presence of metallic copper or a copper compound in an acidic medium under heating, making the reaction mixture alkaline and then subjecting the resulting reaction mixture to hot-filtration, whereby the aqueous solution is obtained as a filtrate.
- 11. A process for producing a 4,4'-diamino1,1'-dianthraquinonyl-3,3'-disulfonic acid or a salt thereof, which comprises preparing an aqueous solution containing a crude 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid or a salt thereof, and mixing an inorganic salt with the aqueous solution to effect salting-out, the aqueous solution being adjusted to an acidic PH after or before the mixing of the inorganic salt with the aqueous solution, whereby a 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid or a salt thereof useful as such for production of a 4,4'-diamino-1,1'-dianthraquinonyl red pigment is produced.
- 12. The process according to claim 11, wherein the aqueous solution containing a crude 4,4'-diamino-1,1'-dianthraquinonyl-3,3'-disulfonic acid or a salt thereof is prepared by allowing a 1-amino-4-halogenoanthraquinone-2-sulfonic acid or a salt thereof to react in the presence of metallic copper or a copper compound in an acidic medium under heating, making the reaction mixture alkaline, and subjecting the resulting reaction mixture to hot-filtration to remove a copper compound formed during the reaction.
Priority Claims (2)
Number |
Date |
Country |
Kind |
3-009108 |
Jan 1991 |
JPX |
|
3-051129 |
Mar 1991 |
JPX |
|
Parent Case Info
This is a continuation of application No. 0 7/818,146, filed on Jan. 8, 1992 , now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (5)
Number |
Date |
Country |
251457 |
May 1963 |
AUX |
1546120 |
Nov 1968 |
FRX |
787716 |
Dec 1957 |
GBX |
926514 |
May 1963 |
GBX |
1149819 |
Apr 1969 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Chemical Abstracts 60:698e. |
Continuations (1)
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Number |
Date |
Country |
Parent |
818146 |
Jan 1992 |
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