The invention relates to the manufacture of composite pigments containing aluminum hydroxide, and their use for improving the pigment light-scattering efficiency in coatings, plastics, paper and laminates. The composite pigment particles contain pigment particles such as titanium dioxide and precipitated aluminum hydroxide and are manufactured by in-situ precipitation of aluminum hydroxide in an aqueous pigment particle suspension. Use of the composite pigment particles according to the invention, based on titanium dioxide, permits savings on pigment with little or no loss of optical properties. Alternatively, if the pigment content remains unchanged, it is also possible to achieve better optical properties.

Provided are titanium oxide fine particles which are excellent in transparency and are less photocatalytically active while maintaining a high refractive index, a dispersion of such fine particles, and a method for producing such a dispersion. The method for producing a dispersion of iron-containing rutile titanium oxide fine particles including a step (1) of neutralizing an aqueous metal mineral acid salt solution containing Ti and Fe in Fe.sub.2O.sub.3/(TiO.sub.2+Fe.sub.2O.sub.3)=0.001 to 0.010 to form an iron-containing hydrous titanic acid; a step (2) of adding an aqueous hydrogen peroxide solution to form an aqueous solution of iron-containing peroxotitanic acid having an average particle size of 15 to 50 nm; a step (3) of adding a tin compound so as to satisfy TiO.sub.2/SnO.sub.2=6 to 16; a step (4) of adding a sol of silica-based fine particles which contain Si and a metal element M in SiO.sub.2/MO.sub.x/2=99.9/0.1 to 80/20, the addition being made so as to satisfy SiO.sub.2/(oxides of the other elements)=0.08 to 0.22; and a step (5) of hydrothermally treating the solution obtained in the step (4).

Provided is a millable silicone rubber composition capable of yielding a silicone rubber (cured product) superior in heat resistance. The composition contains:

(A) 100 parts by mass of an organopolysiloxane having at least two silicon atom-bonded alkenyl groups in one molecule, and having an average polymerization degree of not lower than 100;

(B) 5 to 100 parts by mass of a reinforcing silica having a specific surface area of not smaller than 50 m.sup.2/g;

(C) 0.01 to 10 parts by mass of a titanium oxide doped with a transition metal oxide of 0.01 to 5% by mass;

(D) 0.01 to 10 parts by mass of a cerium oxide and/or a cerium hydroxide; and

(E) 0.01 to 10 parts by mass of a curing agent.

The invention relates to a pigment composition for preparing pigmented matt coatings, such as matt paints and printing inks. Further, the invention relates to a process for preparing such pigment composition, and to a coating formulation containing such composition. Finally, the invention is directed to a pigmented matt surface of a substrate, and to the use of the pigment compositions disclosed herein for matting substrates.

Provided are: a pigment through which light in a warm color region can pass preferentially and which has high hiding power and is mainly used in cosmetic applications; a method for producing the pigment; and a method for using the pigment. The pigment comprises particles each containing a calcium-titanium composite oxide as a main component, in which it is confirmed that regions each having a paler color than the color of a region surrounding thereof are scattered in a dot-like form in the particles when the particles of the calcium-titanium composite oxide in the pigment are observed in a transmission electron microscopic image at a magnification of 100,000, and the true density of the pigment is 3500 kg/m.sup.3 to 3790 kg/m.sup.3, inclusive.

The invention relates to a matting agent comprising agglomerates of pigment particles, to a method for the preparation of such matting agents, and to coating formulations containing the matting agents disclosed herein. The present invention further relates to pigmented mat surfaces, and to the use of agglomerates of pigment particles for matting pigmented coatings.

The purpose of the present invention is to provide: a composite pigment, and production method thereof, which can suppress luster of a coating film by modifying an inorganic coloring pigment, and which can be used in various applications such as low-gloss (luster reduction effect) pigments and matte pigments; a paint composition which can achieve both an excellent coating film texture and also the property of having low gloss and luster even when added to a coating film; and a coating film. In this composite pigment, the inorganic coloring pigment is fixed by an inorganic compound, and a plurality of particles of the inorganic coloring pigment are aggregated into granular form through the inorganic compound.

The purpose of the present invention is to provide a composite pigment which can be dispersed and made into paint in a manner that saves labor compared with conventional flat emulsion paints, and which can achieve concealing properties and low glossiness (a luster reduction effect) without separately adding a matting agent. This composite pigment contains an inorganic compound and/or an organic compound, and a fixed extender pigment.

A dispersion that inorganic oxide microparticles may be dispersed at a high concentration in a solvent, a composition for film formation having high transparency, high refractive index and adhesion to a base layer. Inorganic oxide microparticles wherein an amphiphilic organosilicon compound having one or more selected from a polyoxyethylene group, a polyoxypropylene group, or a polyoxybutylene group as a hydrophilic group, and one or more selected from a C.sub.1-18 alkylene group or a vinylene group as a hydrophobic group bonded to a surface of modified metal oxide colloidal particles (C) having a primary particle diameter of 2 to 100 nm, the modified metal oxide colloidal particles wherein a surface of metal oxide colloidal particles (A) having a primary particle diameter of 2 to 60 nm as a nucleus is coated with a coating material (B) including metal oxide colloidal particles having a primary particle diameter of 1 to 4 nm.

Opaque fluoride-doped effect pigments having a metallic lustre based on flake-form substrates, and a process for the preparation of these pigments, and the use thereof, in particular in automotive paints and cosmetic formulations.