JP2864244B

PURPOSE:To prevent changes in the characteristics of a pigment itself to thereby provide a persistent pigment function, by forming a dry coating of metal on the surface of a pigment powder through sputtering, and treating the coated powder with a silane coupling agent. CONSTITUTION:A pigment having a thin functional coating film is prepared by forming a 10-100Angstrom thick dry coating of a metal or metal oxide on the surface of a pigment powder through sputtering and treating the coated powder with a silane coupling agent. An especially preferred metal or metal oxide for dry coating is titanium, aluminum, silicon or an oxide thereof. It is desirable to adjust the thickness of a coating film to about 10-100Angstrom when said dry coating is formed. Treatment with a silane coupling agent can be performed by any of the aqueous solution method, the organic solvent method, and the spraying method; however, the most preferred is the organic solvent method from the viewpoint of fast drying.