Abstract: A magnesium oxide single crystal having controlled crystallinity has a subboundary, and ranges of variation of diffraction line positions, as measured for reciprocal lattice maps with respect to a region surrounded by the same subboundary, with the range of the variation of 1×10?3 to 2×10?2 degree of on ?? coordinates, and with the range of the variation of 4×10?4 to 5×10?3 degree on 2? coordinates.

Abstract: A phosphorus-containing coated magnesium oxide powdered material comprising a coated magnesium oxide powdered material having a surface coating layer comprised of a double oxide, wherein the phosphorus-containing coated magnesium oxide powdered material has a coating layer comprised of a magnesium phosphate compound in at least part of a surface of the coated magnesium oxide powdered material, wherein the content of the magnesium phosphate compound in the coated magnesium oxide powdered material is 0.1 to 10% by mass, in terms of phosphorus; a method for producing a phosphorus-containing coated magnesium oxide powdered material, wherein the method comprises treating a coated magnesium oxide powdered material having a surface coating layer comprised of a double oxide with a phosphorus compound, and then calcining the resultant powdered material at 300° C.

Abstract: A magnesium oxide single crystal having controlled crystallinity comprising a subboundary, and ranges of variation of diffraction line positions, as measured for reciprocal lattice maps with respect to a region surrounded by the same subboundary, with the range of the variation of 1×10?3 to 2×10?2 degree of on ?? coordinates, and with the range of the variation of 4×10?4 to 5×10?3 degree on 2? coordinates.

Abstract: A phosphorus-containing coated magnesium oxide powdered material comprising a coated magnesium oxide powdered material having a surface coating layer comprised of a double oxide, wherein the phosphorus-containing coated magnesium oxide powdered material has a coating layer comprised of a magnesium phosphate compound in at least part of a surface of the coated magnesium oxide powdered material, wherein the content of the magnesium phosphate compound in the coated magnesium oxide powdered material is 0.1 to 10% by mass, in terms of phosphorus; a method for producing a phosphorus-containing coated magnesium oxide powdered material, wherein the method comprises treating a coated magnesium oxide powdered material having a surface coating layer comprised of a double oxide with a phosphorus compound, and then calcining the resultant powdered material at 300° C.

Abstract: The present invention is related to a magnesium oxide particle aggregate with the requirement of a first inflection point diameter is more than 0.30×10?6 to 0.60×10?6 m, a particle void volume is 0.50×10?3 to 0.90×10?3 m3·kg?1, and a micropore volume is 0.04×10?3 to 0.11×10?3 m3·kg?1 in the cumulative intrusion volume curve of said particle by having controlled particle aggregation structure so that the solid phase-solid phase reaction between magnesium oxide and the SiO2 film on the surface can be appropriately controlled.

Abstract: An object of the present invention is to provide a magnesium oxide particle aggregate having a controlled particle aggregation structure so that the solid phase-solid phase reaction between magnesium oxide and the SiO2 film on the surface can be appropriately controlled. The object can be achieved by a magnesium oxide particle aggregate characterized in that a first inflection point diameter is 0.30×10−6 m or less, an interparticle void volume is 1.40×10−3 to 2.20×10−3 m3/kg and a particle void volume is 0.55×10−3 to 0.80×10−3 m3/kg in a cumulative intrusion volume curve of the particle aggregate.

Abstract: A metal hydroxide solid solution and a metal oxide solid solution, wherein the crystal form is an octahedron comprising upper and lower parallel basal planes and six peripheral pyramidal planes, the pyramidal planes consisting of upward-inclined planes and downward-inclined planes which are alternatively located. The ratio of the major axis diameter of the basal plane to the thickness between the upper and lower basal planes (major axis diameter/thickness) if 1 to 9. This improves fluidity, processability and the like when the solid solutions are kneaded into resins and the like.

Abstract: A production method of a magnesium hydroxide solid solution, Mg.sub.1-x M.sup.2+ .sub.x (OH).sub.2 or a resin and/or rubber material having as its effective elements containing said solid solution as its flame retardant, characterized by having M.sup.2+ distributed unevenly in a high concentration in the vicinity of the surface of each crystal, in the magnesium solid represented by the formula Mg.sub.1-x M.sup.2+ .sub.x (OH).sub.2 wherein M.sup.2+ is at least one divalent metal ion selected from the group consisting of Mn.sup.2+, Fe.sup.2+, Ni.sup.2+, Cu.sup.2+, Zn.sup.2+ and x indicates a range of 0.001.ltoreq.x<0.5.

Abstract: A composite metal hydroxide is produced by reacting magnesium-containing aqueous solution (X) including water soluble zinc compound wherein magnesium ion concentration is 0.01 to 1 mol/liter with alkaline material (Y) at a specific reaction equivalent ratio. Further, a composite metal hydroxide represented by the following general formula (1) is produced by hydrothermally treating thus obtained composite metal hydroxide within a temperature range of 100.degree. to 200.degree. C. for aging in chlorine-containing aqueous solution having a specific chlorine ion concentration:Mg.sub.1-x Zn.sub.x (OH).sub.2 (1)wherein x indicates a positive number within a range of 0.003.ltoreq.x.ltoreq.0.1. A uniform metallic solid solution can be obtained as a composite metal hydroxide by the above series of processes. Further, its crystal shape can be controlled thereby so as to restrain occurrence of secondary aggregation.

Abstract: By hydrating a metal oxide solid solution shown as the following formula (3), wherein an average primary crystal particle diameter is in the range of 1 to 10 .mu.m, in the presence of monocarboxylic acid and/or oxymonocarboxylic acid in aqueous medium,Mg.sub.1-z M.sup.2+.sub.z O (3)in which M.sup.2+ represents at least one divalent metal ion selected from the group consisting of Mn.sup.2+, Fe.sup.2+, Co.sup.2+, Ni.sup.2+, Cu.sup.2+ and Zn.sup.2+, and z is in the range of 0.01.ltoreq.z<0.5, a metal hydroxide solid solution having a high aspect ratio shown as the following formula (1) can be obtained;Mg.sub.1-x M.sup.2+.sub.x (OH).sub.2 (1)in which M.sup.2+ represents at least one divalent metal ion selected from the group consisting of Mn.sup.2+, Fe.sup.2+, Co.sup.2+, Ni.sup.2+, Cu.sup.2+ and Zn.sup.2+, and x is in the range of 0.01.ltoreq.x<0.5, characterized by that a crystal is a hexagonal plate in shape, 0.01 to 0.5 .mu.m in average thickness, 1 to 10 .mu.

Abstract: A flame retardant polyolefin compound having low smoking and toxicity comprising 100 parts by weight of polyolefin resin, 100 to 150 parts by weight of a flame retardant, and 2 to 10 parts by weight of zinc stannate as a flame retardant auxilliary agent. The flame retardant polyolefin compound preferably uses a composite metal hydroxide as the flame retardant.

Abstract: A flame retardant polyolefin composition comprising polofin resin and a flame-retarding component which is prepared by adding 1 to 20 parts by weight of fine carbon powder to 100 parts by weight of composite metal hydroxide expressed by the general formula Mg.sub.1-x M.sup.+2.sub.x (OH).sub.2 in which M.sup.+2 is at least one element selected from the group consisting of bivalent metallic ions Mn.sup.+2, Fe.sup.+2, Co.sup.+2, Ni.sup.+2, Cu.sup.+2 and Zn.sup.+2, and x has a value satisfying 0.001.ltoreq.x.ltoreq.0.9.

Abstract: A disposable body warmer comprises a heat generating material and a structure for retaining the material. The retaining structure may be provided on its one side with a reflecting material. The heat generating material consists essentially of at least one oxide of alkaline earth metals such as magnesium oxide with a plate crystal structure and, if necessary, contains an additive such as a salt selected from the group consisting of chlorides and sulphides of alkali metals and alkaline earth metals.