| 摘要 |
PURPOSE:To obtain a black pigment which is excellent in applicability such as covering power and spread and causes neither agglomeration when incorporated in a cosmetic preparation nor color separation when applied onto the skin, by forming a thin interlayer comprised of a metal oxide or its hydrate on the surface of an inorg. and/or organic powdery material and then depositing triiron tetroxide on the interlayer. CONSTITUTION:A thin interlayer comprised of a metal oxide or its hydrate is first formed on the surface of an inorg. and/or org. powdery material. An aq. soln. contg. a ferrous (II) salt and an oxidizing agent is added in portions in the presence of a base to an aq. suspension contg. the inorg. and/or powdery material coated with the interlayer. Thus, triiron tetroxide is deposited on the surface of the inorg. and/or org. powdery material coated with the interlayer, thereby coating it with the triiron tetroxide. The percentage coating of the interlayer is about 0.01-20wt% based on the weight of the powdery material. Examples of the metal oxide or its hydrate employed as the interlayer include iron oxide, aluminum oxide, nickel oxide, chromium oxide and their hydrates.
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