Abstract: Described is a coating composition comprising a liquid medium containing a titanium dioxide pigment and a coating film formation resin said titanium dioxide pigment being in the form of flaky or fin-like small pieces of silicon dioxide covered by titanium dioxide and having a diameter of 1 to 300 microns and a thickness of 0.001 to 1 micron, a considerable portion of said silicon dioxide being dissolved out from said titanium dioxide-coated silicon dioxide small pieces.

Abstract: The invention relates to a method for the preparation of transparent metal oxide pigment, in which a substantial portion of the silicon oxide is dissolved off from silicon dioxide based particles coated with transparent metal oxide, and to a transparent metal oxide pigment prepared by the method. In the extraction methods according to the prior art the problem is that in the extraction a part of the metal oxide is also dissolved, whereby thickness variations impairing the interference color of the metal oxide layer are created. Moreover, in the known methods hard-treated extraction chemicals which are detrimental for the environment are used. These problems have by means of the present invention been solved so that such particles are selected for the dissolution whose silicon dioxide portion is substantially soluble in base and metal oxide portion is substantially insoluble in base, and the dissolution is carried out by base.

Abstract: The invention relates to platey silicate particles coated with a metal oxide insoluble in mineral acids, by means of which a nacreous effect is obtained. In the method there is prepared a preliminary-stage product of coated silicate particles, and the particles thus obtained are leached by using a mineral acid, possibly together with some oxidant, whereupon the substrate dissolve selectively so that only the silica skeleton is left.