Title:
PURE-COLORED IRON OXIDE DIRECT RED PIGMENT AND ITS PRODUCTION AS WELL AS ITS USE
Document Type and Number:
Japanese Patent JP3868511
Kind Code:
B2
Abstract:
PURPOSE: To obtain a pure-colored iron oxide red pigment which is ecologically completely harmless by regulating a pH to a prescribed value by addition of an alkaline soln. after the end of pigment formation and heating the pigment under prescribed conditions without ventilation.
CONSTITUTION: A gamma Fe2O3 species suspension of about 63 m3 having Fe2O3 concn. of about 17.3 g/L is added into a reactor of 100 m3. About 5000 kg FeSO4 (a soln. contg. about 200 g/L FeSO4) is added to the suspension by a pump and the soln. is heated to about 85°C (usually 70 to 95°C). An NaOH soln. is then added thereto at a rate of 90 kg/hour by the pump. Further, air is supplied thereto at 300 m3/hour. The pigment formation is stopped after about 9 hours (usually 0.5 to 30 hours) and the pH is adjusted to 4.2 (usually 3.0 to 5.5) by addition of NaOH. The suspension is stirred for about 3 hours without ventilation. The product is filtered and the filtrate is dried at about 85°C and is pulverized. The resulted product is the iron oxide pigment having a red component (a*) larger than 33CIELAB unit in a building material test.
Inventors:
Klaus Lerch
Gunter Buxbaum
Peter Chiemle
Rolf Naumann
Gunter Buxbaum
Peter Chiemle
Rolf Naumann
Application Number:
JP24828394A
Publication Date:
January 17, 2007
Filing Date:
September 19, 1994
Export Citation:
Assignee:
Bayer Aktiengesellschaft
International Classes:
C01G49/02; C01G49/06; C09C1/24; (IPC1-7): C01G49/02
Domestic Patent References:
| JP49032711B1 | ||||
| JP60003012B1 | ||||
| JP6115945A | ||||
| JP6256022A | ||||
| JP6211524A |
Attorney, Agent or Firm:
Heikichi Odashima
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