A surface-treated aggregated boron nitride powder is prepared by using the boron nitride powder as the raw material, adding an oxidizer to the boron nitride aggregated grains, wet-pulverizing or wet-crushing the grains for surface modification treatment of the particles and allowing reaction of the particles with a metal coupling agent. The surface-treated boron nitride aggregated grains are formed by aggregation of hexagonal h-BN primary particles; (B) have any one or more of Si, Ti, Zr, Ce, Al, Mg, Ge, Ga, and V in an amount of 0.1 atm % or more and 3.0 atm % or less in its composition on the surface of 10 nm; (C) have a crushing strength of 5 MPa or more; and (D) have an average particle diameter of 20 μm or more and 100 μm or less.

There is provided a modified zirconium phosphate tungstate which effectively suppresses the elution of phosphorus ions even when it contacts with water, can develop the performance excellent as a negative thermal expansion material, and can be dispersed in a polymer compound such as a resin, and use of which enables a low-thermal expansive material containing a negative thermal expansion filler to be well produced. The surface of a zirconium phosphate tungstate particle is coated with an inorganic compound containing one or two or more elements (M) selected from Zn, Si, Al, Ba, Ca, Mg, Ti, V, Sn, Co, Fe and Zr. The BET specific surface area of the zirconium phosphate tungstate particle is preferably 0.1 m.sup.2/g to 50 m.sup.2/g.

A surface-treated aggregated boron nitride powder is prepared by using the boron nitride powder as the raw material, adding an oxidizer to the boron nitride aggregated grains, wet-pulverizing or wet-crushing the grains for surface modification treatment of the particles and allowing reaction of the particles with a metal coupling agent. The surface-treated boron nitride aggregated grains are formed by aggregation of hexagonal h-BN primary particles; (B) have any one or more of Si, Ti, Zr, Ce, Al, Mg, Ge, Ga, and V in an amount of 0.1 atm % or more and 3.0 atm % or less in its composition on the surface of 10 nm; (C) have a crushing strength of 5 MPa or more; and (D) have an average particle diameter of 20 μm or more and 100 μm or less.

Disclosed in certain embodiments is a method of preparing structural colorants comprising photonic particles, the method comprising varying the calcination temperature in the process to enable the tuning of pore size to obtain a wide variety of possible colors.

A composite pigment containing a substrate particle and a pigment layer arranged on a surface of the substrate particle, wherein the pigment layer contains a pigment, a resin and a metal oxide, and the metal oxide contains at least one selected from the group consisting of a silicon oxide, a polysiloxane, and composites thereof.

A foundry dust compound reinforcing filler for natural rubber contains 40-80 parts by weight of foundry dust, 10-40 parts by weight of silica and 10-40 parts by weight of Carbon black. A method for preparing a foundry dust compound reinforcing filler for natural rubber includes the steps of sieving, iron removal, pickling, precipitation, primary grinding, mixing, secondary grinding, granulation and the like. The foundry dust compound reinforcing filler used for reinforcing natural rubber is easy to disperse in natural rubber. The compound reinforcing filler has excellent reinforcing effect, which realizes the resource utilization of casting dust waste and reduces the consumption of silica and carbon black.

Disclosed in certain embodiments is a liquid coating composition comprising a liquid medium and a structural colorant comprising photonic particles comprising a metal oxide, the photonic particles having silane functional groups on at least a portion of the external surface of the photonic particles.

The invention provides a method for applying a new form of protective coating to substrates such as pigments, and also the coated substrates obtainable by this method. The coating are characterized by the fact that they impart good chemical resistivity to the substrate whilst also preserving its optical properties.

A zirconium nitride powder coated with alumina has a volume resistivity is 1×10.sup.6 Ω.Math.cm or higher. Also, an coating amount with alumina is 1.5% by mass to 9% by mass with respect to 100% by mass of the zirconium nitride. Furthermore, an isoelectric point of the zirconium nitride powder coated with alumina is 5.7 or higher.

The disclosure relates to a method for mechanochemical preparation of an iron red pigment, which comprise steps: mixing a clay mineral, a soluble iron source and an alkali source in a mill for grinding to obtain a precursor, wherein the ratio of ball to material is controlled at 20-50, the grinding speed is 300-1200 rpm, and the grinding time is 30-360 min; and calcining the precursor at 500-900° C. for 30-120 min to obtain a high-performance iron oxide red/clay mineral hybrid pigment. The iron oxide red/clay mineral hybrid pigment has a bright and beautiful color, high-temperature and acid resistance, and can satisfy requirements for high-performance iron oxide red pigments in fields of paints, inks, ceramics, anti-corrosive coatings, etc. Furthermore the method is a simple process without waste that is environmentally friendly and suitable for industrialized production, thus it is expected to replace existing processes of iron oxide red pigments.