Process for producing dispersion of functional compound

Abstract

There are provided a finely dispersed material of a functional compound such as pigment or the like in the state of its inherent average particle diameter and a process for producing a finely dispersed material of a functional compound into a binder resin, in which the compound is dispersed in the state of its inherent average particle diameter not more than 3 microns, in spite of using the functional compound having an apparently large average particle diameter by agglomeration in comparison with the inherent average particle diameter of the compound, wherein when the above compound before dispersion is apparently in the dry state, de-ionized water is added thereto to form a hydrous paste of the compound and then this hydrous paste is contacted with a substance having an ion-exchange function selected depending upon the properties of the impurity ions contained in the above functional compound in a mixed solvent composed of de-ionized water and an organic solvent miscible with water to remove the impurity ions, and the impurity ion-free hydrous paste thus obtained is thereafter dispersed in the binder resin, or when the above compound before dispersion is already in the form of a hydrous paste, this hydrous paste is directly contacted with the selected substance having ion-exchange function by the same method described in the case of the dry state, and the impurity ion-free hydrous paste thus obtained is thereafter dispersed in the binder resin.