Abstract: Provided are magnesium hydroxide particles having a hexagonal crystal form and having an aspect ratio (H) which satisfies the following expression (I), 0.45·A·B<H<1.1·A·B??(I) (wherein H is an aspect ratio, A is an average secondary particle diameter (?m) of all of the particles measured by a laser diffraction scattering method and B is a specific surface area (m2/g) of all of the particles measured by a BET method), a flame-retardant comprising the particles, a flame-retardant resin composition comprising 100 parts by weight of a synthetic resin and a 5 to 300 parts by weight of the magnesium hydroxide particles, and a molded article therefrom. The magnesium hydroxide particles are hexagonal single crystals, the hexagonal form thereof are not necessarily required to be regular hexagonal, and the size thereof are not necessarily constant.

Abstract: Provided are magnesium hydroxide particles having a hexagonal crystal form and having an aspect ratio (H) which satisfies the following expression (I), 0.45·A·B<H<1.1·A·B  (I) (wherein H is an aspect ratio, A is an average secondary particle diameter (&mgr;m) of all of the particles measured by a laser diffraction scattering method and B is a specific surface area (m2/g) of all of the particles measured by a BET method), a flame-retardant comprising the particles, a flame-retardant resin composition comprising 100 parts by weight of a synthetic resin and a 5 to 300 parts by weight of the magnesium hydroxide particles, and a molded article therefrom. The magnesium hydroxide particles are hexagonal single crystals, the hexagonal form thereof are not necessarily required to be regular hexagonal, and the size thereof are not necessarily constant.

Abstract: Provided are magnesium hydroxide particles having a hexagonal crystal form and having an aspect ratio (H) which satisfies the following expression (I),

Abstract: A flame-retardant for a synthetic resin, which is obtained by surface-treating a magnesium hydroxide with an emulsion of a copolymer or polymer of the formula (1), wherein X is hydrogen, a phenyl group, etc., Y is an alkyl group, etc., each of R1 and R2 is hydrogen, an alkyl group, etc., m is 0 or a positive integer, n is a positive integer, and “˜” shows the polymerization state of a main chain, the formula (2), wherein X, Y, etc. are as defined in the formula (1), or the formula (3), wherein X and “˜” are as defined in the formula (1), each of Y1 and Y2 is hydrogen, an alkyl group, etc., each of R1, R2 and R3 is hydrogen or an alkyl group, and each of a, b and c is a positive integer, a resin composition containing said flame-retardant and a molded article thereof.

Abstract: A process for the production of coupling agent-treated inorganic particles, which process is excellent in surface-treatment uniformity and uses a coupling agent at high coefficient of utilization, the process comprising adding a solution of a coupling agent into an aqueous suspension of inorganic particles with stirring and, after the mixing with stirring, heat-drying the resultant suspension without dehydration by filtration and concentration, and a synthetic resin composition containing the above particles and having excellent properties.

Abstract: An acid-resistant, thermoplastic resin composition which is nonpoisonous and non-halogen and has an acid-resistance for a long period of time, the acid-resistant, thermoplastic resin composition containing a thermoplastic resin, 30 to 70% by weight of magnesium hydroxide which has a specific surface area of 20 m2/g or less and an average secondary particle diameter of 0.2 to 5.0 &mgr;m and is surface-treated with at least one surface-treating agent selected from a water-soluble silane-coupling agent, a phosphoric acid ester, a higher fatty acid or its alkali metal salt, and 1 to 20% by weight of a reaction type compatibilizing agent.

Abstract: Disclosed are ultraviolet light protective agents having the general formula:(Zn.sub.y M.sup.2+.sub.z).sub.1-x M.sup.3+.sub.x O.sub.1+x/2wherein M.sup.2+ is at least one metal selected from the group consisting of Mg, Ca, Ni and Cu; and M.sup.3+ is at least one metal selected from the group consisting of Al and Fe; as well as a sterilizer and a deodorizer which contain the compound of the above formula (I) as an effective component. They are additives to plastics, rubber, cosmetic materials, and paint and also useful as sterilizer or deodorizer, composition components.

Abstract: A resin composition containing a hydrotalcite compound in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the thermoplastic resin, the hydrotalcite compound having fine crystals of copper oxide deposited on the surface thereof; and a molded article formed of the above resin composition. The resin composition and the molded article formed thereof have excellent heat resistance and weatherability.