Inorganic colorant, colorant-dispersed paste, and paint containing the same

In a paint comprising:

• water,
• a resin, having a neutralized acidic or basic functional group, dissolved in said water, as a vehicle for said paint and
• particles of at least one inorganic colorant which has surface hydroxyl groups and, as a consequence, a high surface polarity, dispersed in said water in which said resin is dissolved;
• the improvement, whereby reducing the free energy at an interface between said inorganic colorant particles and said resin, which comprises:
• the surface of high polarity of said inorganic colorant particles being at least partially covered with a coating consisting essentially of an amount of a non-polar crosslinked organic polymer sufficient to form enough of a nonpolar surface on the surface of said colorant particles to reduce the polarity of the surface of said inorganic colorant particles, to increase the affinity of said thus covered inorganic colorant particle surface to said resin, and to thereby increase the dispersibility of said covered inorganic colorant particles in said water in which said resin is dissolved;
• said surface covering having been achieved by subjecting said inorganic colorant particles to low temperature plasma polymerization of a polymerizable organic compound under conditions sufficient to at least partially cover the surface thereof, which has high polarity, with said crosslinked polymer.