To obtain the subject inexpensive suppressant which is nontoxic or extremely slightly toxic and excellent in heat resistance and weatherability by including a solid solution selected from specific four compounds as an active ingredient.
This suppressant contains, as an active ingredient, a solid solution selected from (A) a solid solution of hydroxide of the formula, [(M12+)y(M22+)1-y]1-yM3+X(OH)2(An)y/n.mH2O [0≤(y)≤1; 0<(x) ≤0.5; 0≤(m)2; M12+ is Zn2+ or Cu2+; M22+ is Mg2+ or Ca2+, M3+ trivalent metal; An is (n)-valent anion], (B) an oxide solid solution of the formula, [(M12+)y(M22+)1-y]1-xM3+x-aO [0≤(y)≤1; 0<(x) ≤0.5; (x-a) represent that number of M3+ is decreased by (a) by lattice defect, (C) a hydroxide solid solution of the formula, [(M12+)x(M22+)1-x(OH)2 [0.0001≤(x)<0.9] and (D) an oxide solid solution of the formula, [(M12+)x(M22+)1-xO (0.0001≤(x)<0.9).
MANABE HITOSHI
SHIMADA TERUKO
KAISUI KAGAKU KENKYUSHO KK