FLAME RETARDANT, FLAME RETARDANT COMPOSITION AND MOLDED BODY

PROBLEM TO BE SOLVED: To provide a flame retardant, a flame retardant composition and a molded body good in dispersibility to organic polymer materials without reducing material physical properties thereof even after combining with the organic polymer materials.SOLUTION: There is provided a flame retardant containing surface treated magnesium hydroxide particle satisfying following (A) to (D). (A) average particle diameter by a laser diffraction method of 2 μm or less. (B) BET specific surface area is 3 to 15 m/g. (C) single dispersion degree represented by the following formula is 50% or more; single dispersion degree (%)=(average primary particle diameter by an SEM observation [μm]/average particle diameter by the laser diffraction method [μm]×100. (D) pH of a suspension by a potentiometric titration just after dropping 0.1 M nitric acid 1 mL at a dropping rate of 0.1 mL/min. to the suspension where the flame retardant of 1.0 g to 100 mL of a mixture solution containing a wetting agent and an electrolyte of 0.1 wt.% respectively is 9.0 or less.SELECTED DRAWING: Figure 1 【課題】有機高分子材料への分散性が良好であり、有機高分子材料と組み合わせた後でもその材料物性の低下をきたさない難燃剤、難燃性組成物及び成形体を提供すること。【解決手段】以下の（Ａ）〜（Ｄ）を満たす表面処理された水酸化マグネシウム粒子を含む難燃剤：（Ａ）レーザー回折法による平均粒子径が２μｍ以下；（Ｂ）ＢＥＴ比表面積が３〜１５ｍ２／ｇ；（Ｃ）下記式で表わされる単分散度が５０％以上；単分散度（％）＝（ＳＥＭ観察よる平均１次粒子径［μｍ］／レーザー回折法による平均粒子径［μｍ］）×１００；及び（Ｄ）湿潤剤及び電解質をそれぞれ０．１重量％で含有する混合水溶液１００ｍＬに前記難燃剤１．０ｇを添加した懸濁液に０．１Ｍ硝酸を０．１ｍＬ／分の滴下速度で１ｍＬ滴下した直後の電位差滴定による前記懸濁液のｐＨが９．０以下。【選択図】図１