Core particles produced in situ or introduced as preformed core particles are coated with a layer of carbon. Non-carbon as well as some carbon-based core materials can be utilized. The resulting carbon coated particles can find applications in rubber products, for instance as reinforcement for tire components.

Provided is a novel magnesium carbonate. The magnesium carbonate has a zeta potential of 5 mV or more and a BET specific surface area of 25 m.sup.2/g or more. Such a magnesium carbonate can be used as a resin additive, etc.

Coated magnesium oxide particles having high filling efficiency and high mass-productivity and suitable for a thermal conductive filler are provided, the coated magnesium oxide particles being coated magnesium oxide particles in which the surface of magnesium oxide particles is coated with at least one of a fatty acid and a fatty acid metal salt, and wherein X in relation to particles is defined as X=[a BET specific surface area diameter calculated from a BET specific surface area of the particles][D.sub.50 of the particles], provided that D.sub.50 is a particle diameter at 50% accumulation in a cumulative particle size distribution of the particles, the magnesium oxide particles having X of less than 0.2 and D.sub.50 of 5 to 100 m, and the coated magnesium oxide particles having X of 0.2 or more, D.sub.50 of 5 to 100 m, and oil absorption of less than 25 mL/100 g.

Core particles produced in situ or introduced as preformed core particles are coated with a layer of carbon. Non-carbon as well as some carbon-based core materials can be utilized. The resulting carbon coated particles can find applications in rubber products, for instance as reinforcement for tire components.

A composite particle of the present invention includes an inorganic particle and a graphene oxide particle that coats at least a part of the inorganic particle, and the graphene oxide particle is a modified graphene oxide particle having a surface modified with a hydrocarbon group optionally having a substituent.

Provided is a method for producing a surface-treated thermally conductive filler, the method including treating the surface of the thermally conductive filler with an alkoxysilane having a specific structure by the chemical vapor deposition method.

A scattering particle includes a core and a shell, wherein the shell includes a first layer including a compound capable of reacting with oxygen and/or moisture, and a second layer including a compound decomposable by light and/or heat.

A resin-coated metal powder according to the present invention is obtained by covering at least a part of the surface of a metal powder with a hydrolyzable resin that has an average composition of general formula (1) and a number average molecular weight of from 500 to 100,000; and this resin-coated metal powder exhibits sufficient dispersibility in an aqueous solution, while being stable for a relatively long period of time even in the coexistence of water in an aqueous coating material.

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(In the formula, R.sup.1 represents a linear or branched monovalent hydrocarbon group having from 1 to 10 carbon atoms, said group optionally having a specific substituent such as a hydroxyalkyl group; each of R.sup.3, R.sup.4 and R.sup.5 independently represents a linear or branched monovalent hydrocarbon group having from 1 to 10 carbon atoms; each of R.sup.2 and R.sup.6 independently represents a hydrogen atom or a linear or branched monovalent hydrocarbon group having from 1 to 10 carbon atoms; and a and b represent numbers that satisfy 0a<1, 0<b1 and (a+b)=1.)

To provide magnesium oxide which is excellent in hydration resistance and hardly causes volume expansion due to hydration and the like, a resin composition containing the same, and a method for producing the magnesium oxide powder. Magnesium oxide powder having a coating layer mainly comprising basic magnesium carbonate in the surface layer, when the amounts of substances of water vapor and carbon dioxide among the gas generated by thermal decomposition at 50 to 500 C. are respectively designated as m-H.sub.2O and m-CO.sub.2, in a heating evolved gas analysis (EGA-MS) method, the molar fraction represented by m-CO.sub.2/(m-H.sub.2O+m-CO.sub.2) being within the range of 0.3 to 0.6.

The invention relates to a material comprising at least 97% by weight alkaline earth metal carbonates having a calcium oxide content of 0.3% by weight or less and a particle size group of 0.1 to 1.8 mm. The invention furthermore relates to a method for the preparation thereof and also the use thereof for deacidification, filtration and/or hardening of liquids.