Inkjet recording ink and production method thereof

1 . A production method of an inkjet recording ink comprising a dispersion medium and coloring material particles containing at least a coloring material, which method comprises a step of removing minute coloring material particles from the coloring material particles.

2 . The production method of an inkjet recording ink as claimed in claim 1 , wherein by the step of removing minute coloring material particles from the coloring material particles, a content of coloring material particles having a size of ⅕ or less of a volume average diameter of the coloring material particles is reduced to 5% by volume or less based on the total coloring material particles.

3 . The production method of an inkjet recording ink as claimed in claim 2 , wherein the step of removing the minute coloring material particles from the coloring material particles is conducted by a means employing gravity, centrifugal force, interface characteristics of the coloring material particle or a combination thereof.

4 . The production method of an inkjet recording ink as claimed in claim 3 , wherein the means employing gravity is a means of using a spontaneous precipitation method.

5 . The production method of an inkjet recording ink as claimed in claim 3 , wherein the means employing centrifugal force is a centrifuge or a liquid cyclone.

6 . The production method of an inkjet recording ink as claimed in claim 3 , wherein the means employing the interface characteristics of the coloring material particle is a means of using an electrophoresis.

7 . An inkjet recording ink obtained by the production method of an inkjet recording ink as claimed in claim 1 .

8 . An inkjet recording ink obtained by the production method of an inkjet recording ink as claimed in claim 2.