| abstract |
An amorphous particulate additive for resins having (1) a molar ratio of SiO 2 to Al 2 O 3 from 2.1:1 to 3.3:1 on the basis of the oxides, (2) an average particle diameter of from 0.3 to 10 µm, (3) a moisture regain at equilibrium (RH90%) of not greater than 10%, (4) a bulk density of from 0.5 to 1.2 g/ml, and (5) a pH in the form of an aqueous suspension of from 6 to 10, said amorphous particles being obtainable by acid-treatment followed by heat-treatment of a Pc zeolite having a spherical particle shape, a notched surface and a molar ratio of SiO 2 to Al 2 O 3 from 2:1 to 3.4:1 on the basis of the oxides, said amorphous particles having substantially the same particulate structure as that of said Pc zeolite and having a definite shape. |