Disclosed is
hydrotalcite having properties and
sodium content limited to ultra-
low volume, a method for preparing same, and a
synthetic resin composition
hydrotalcite containing same. (1) In the general formula [M(II)y M(II)z]1-x(Al)x(OH)2(CO3)2- (x) / n mH2O, M(II) represents Mg2+, Zn2+, Ca2+, Li2+, which are
divalent metal ions, M(III) represents Al3+, which is a trivalent
metal ion, A represents an anion (CO3 2-), and x, y, z, and m represent the values that satisfy the following conditions: 0.2=x<0.4, y+z=1, 0.7=y=1, 0=z=0.3, 0=m<1; (2) The
hydrotalcite particles have an average secondary particle
diameter of 0.5~2? when measured using
laser diffraction scattering method. (3) The
sodium content in the hydrotalcite particles is less than 80 weight ppm.; (4) The hydrotalcite particles contain iron compound and
manganese compound at a total volume of less than 0.005 weight% when converted into metals (Fe+Mn). (5) When measured using BET method, the hydrotalcite particles have a specific surface area of 5~40 ? / g, or more desirably 5~20 ? / g.