| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing pigment fine particles by which pigment fine particles each having a nano-sized particle diameter and an anthraquinone structure are easily obtained. <P>SOLUTION: The method for producing pigment fine particles having an anthraquinone structure includes: a first process for obtaining a mixed solution (A) having a liquid temperature (T1) of 50°C or less and including a deposited pigment having an anthraquinone structure by mixing 300-3,000 pts.mass of water with 100 pts.mass of a sulfuric acid solution in which the content of the pigment having the anthraquinone structure is 2-25 mass%; and a second process for adjusting the temperature of the mixed solution (A) to a temperature (T2) equal to or lower than 30°C, at which a solution state is maintained. In the method, adjustment to the temperature (T2) is carried out within 30 sec by setting the time point when the mixed solution (A) is obtained as a starting point. In the first process, when the sulfuric acid solution is mixed with water, various mechanical means, for example, an ejector and an agitation device (micromixer) having micro-passages through which a plurality of fluids flow separately and a mixing part of the plurality of fluids may be used. <P>COPYRIGHT: (C)2012,JPO&INPIT |
