Method of producing composite metal hydroxide, composite metal hydroxide obtained thereby and a flame retardant composition obtained thereby and therewith

摘要

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° to 200° C. for aging in chlorine-containing aqueous solution having a specific chlorine ion concentration:PPMg.sub.1-x Zn.sub.x (OH).sub.2 (1) PPwherein x indicates a positive number within a range of 0. 003≦x≦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. Still further, a flame retardant high-molecular composition obtained by including thus obtained composite metal hydroxide into a high-molecular weight composition exerts high flame retardancy and shows superiority in mechanical strength.