DDR-TYPE ZEOLITE POWDER, AND PROCESS FOR THE PRODUCTION OF DDR-TYPE ZEOLITE POWDER

摘要

Provided are a DDR-type zeolite powder which is composed of fine particles and exhibits a particle size distribution wherein the majority of the particles have particle diameters converging in the vicinity of the mean particle diameter; and a process for the production of same.  Specifically provided is a process for the production of a DDR-type zeolite powder, which comprises a step of heat-treating a raw material solution at 100 to 180°C, and thereby growing crystals until the mean particle diameter reaches to a level of 0.1µm or larger but smaller than 2.5µm. The raw material solution comprises a mixture consisting of a solution of 1-adamantanamine in ethylenediamine, silica (SiO2), and water at a 1-adamantanamine/SiO2 molar ratio of 0.002 to 0.5 and a water/SiO2 molar ratio of 10 to 500; and DDR-type zeolite seed crystals having a mean particle diameter of 10 to 300nm are dispersed in the raw material solution in an amount of 0.001 to 1.0mass%.  The DDR-type zeolite seed crystals act as nuclei for crystal growth in the above step.