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: The coloring problem of a conventional molded article is overcome while retaining the advantages of high strength and high flame retardancy of the molded article when a metal hydroxide is used in combination with red phosphorus and carbon powder in the method of imparting a synthetic resin with flame retardancy. The molded article can be colored in any color and exhibits decreased lowering of electric insulation resistance when submerged. The molded article comprises a base material colored from dark red to black containing 100 wt parts synthetic resin, 5-200 wt parts metal hydroxide, 1-30 wt parts red phosphorus and 0.1-30 wt parts carbon powder; and a skin layer laminated thereon masking a colored surface of the base wherein the skin layer contains 100 wt parts, 0-100 wt parts pigment, and 0-200 wt parts metal hydroxide, provided that the total amount of pigment and metal hydroxide in the skin layer is at least 0.001 wt parts.

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: The coloring problem of a conventional molded article is overcome while retaining the advantages of high strength and high flame retardancy of the molded article when a metal hydroxide is used in combination with red phosphorus and a carbon powder in the method of imparting a synthetic resin with flame retardancy.

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: Zinc-containing hydrotalcite particles which satisfy the following requirements (1) to (4): (1) the chemical composition should be represented by the following formula (A): ZnxAl2(OH)4+2xCO3.mH2O  (A) wherein x and m satisfy 3.5≦x≦4.5 and 0≦m≦4, respectively, (2) the average secondary particle size should be 2 &mgr;m or less, preferably 0.3 to 1.5 &mgr;m, (3) the amount of particles having a particle size of 10 &mgr;m or more out of all the particles should be 1 wt % or less, preferably 0.5 wt % or less, and (4) the specific surface area measured by a BET method should be 20 m2/g or less, preferably 4 to 15 m2/g; and a resin composition comprising 0.001 to 5 parts by weight of the zinc-containing hydrotalcite particles based on 100 parts by weight of the polyolefin resin. This resin composition has excellent heat deterioration resistance, rust formation preventing properties, coloration preventing properties, dispersibility and filter permeability.

Abstract: A flame retardant resin composition comprising (A) 100 parts by weight of a synthetic resin, (B) 20 to 150 parts by weight of magnesium hydroxide particles and (C) 20 to 150 parts by weight of aluminum hydroxide particles, wherein the magnesium hydroxide particles and the aluminum hydroxide particles satisfy the following conditions (i) to (v): (i) the average secondary particle diameter measured by a microtrack method is 0.4 to 4 .mu.m; (ii) the specific surface measured by a BET method is 1 to 15 m.sup.2 /g; (iii) the total content of an iron compound and a manganese compound is 200 ppm or less in terms of metals (Fe+Mn); (iv) the ratio of the specific surface measured by the BET method to the specific surface measured by a Blaine method is 1 to 4; and (v) the content of a water-soluble sodium salt is 500 ppm or less in terms of metal sodium.

Abstract: A flame retardant having heat deterioration resistance which is composed of magnesium hydroxide particles having (i) an average secondary particle diameter, measured by a laser diffraction scattering method, of not more than 2 .mu.m, (ii) a specific surface area, measured by a BET method, of not more than 20 m.sup.2 /g and containing (iii) a total amount of an iron compound and a manganese compound of not more than 0.02% by weight in terms of metals, and a synthetic resin composition comprising the same and a molded article therefrom.

Abstract: A flame retardant having excellent resistance to water and acid for a long period of time and comprising 100 parts by weight of magnesium hydroxide of which the surface is treated with a phosphoric ester of formula (I) ##STR1## wherein R represents an alkyl or alkenyl group having 10 to 30 carbon atoms, M represents an atom belonging to group IA of the periodic table or NH.sup.4+, and n represents 1 or 2, and 0.1 to 10 parts by weight of a salt of a metal other than alkali metals with a higher fatty acid, and a resin composition containing the flame retardant.

Abstract: A miniature switch assembly comprising a base member having a plurality of parallel finned projections, a pair of contact members each having a plurality of contact terminals being fixed on both sides of the base member, respectively, a plurality of lever wheels being disposed between the adjacent finned projections, and a housing having a plurality of partition walls for accommodating the base member with the contact members and the lever wheels, wherein the lever wheels each having conductive plate perform the switching action in a manner that the conductive plate slides over the contact terminals. A locking member is also provided for locking the lever wheels. Preferably, a dust cover is provided for protecting the switch assembly from dust or mechanical injuries.