Claims
- 1. In a pressure finishing process for obtaining an organic pigment having a high tinctorial strength and a narrow grain size distribution, by heating a crude organic pigment as an aqueous suspension having a consistency suitable for being pumped in a continuously operating flow apparatus to a temperature of from 80.degree. to 300.degree. C. and for a period of from 10 seconds to 20 minutes, the improvement whereby pigment press-cakes can be processed directly which comprises heating the suspension of from about 10 to about 30% by weight of crude pigment in a pressure-tight, cylindrical heat exchanger which is provided with moving internal parts, said parts being in contact with said suspension and capable of thoroughly mixing said suspension and simultaneously self-cleaning the heat exchanger surfaces so that good heat transfer is achieved and so that a minimum and uniform dwelling time of the said aqueous suspension in the continuously operating flow apparatus is achieved.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2422182 |
May 1974 |
DEX |
|
Parent Case Info
This application is a continuation of copending application Ser. No. 746,115 filed Nov. 30, 1976, now abandoned, which application Ser. No. 746,115 was a continuation-in-part of copending application Ser. No. 575,067, filed May 6, 1975, now abandoned.
US Referenced Citations (3)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1239042 |
Apr 1967 |
DEX |
2214700 |
Jul 1973 |
DEX |
2336919 |
Jan 1975 |
DEX |
Non-Patent Literature Citations (3)
Entry |
Perry et al., Chem. Eng. Handbook, 5th ed., (1973), pp. 19-21 and 19-22. |
Twin-Screw Compounding Extruder Type ZSK 53/variable, pub. by Werner-Pfleiderer. |
Sales and Spec'n, Pamphlets on AP (All-Phase) Reactors of List, (German Language Portion is 1973, Pub'n). |
Continuations (1)
|
Number |
Date |
Country |
Parent |
746115 |
Nov 1976 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
575067 |
May 1975 |
|