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AssigneesNGK Insulators, Ltd., Masahiko Matsukata
InventorsAkira Takahashi, Toshihiro Tomita, Takuya Hiramatsu, Kenji Suzuki, Masahiko Matsukata
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A highly heat-resistant and hydrothermal-resistant β-zeolite having a SiO2/Al2O3 ratio of 80 or more, which is constituted by primary particles having an average particle diameter of 30 nm or more or by primary particles having such a particle size distribution that the 10% particle diameter is 20 nm or more; and an adsorbent for automobile exhaust gas purification, using said β-zeolite. The β-zeolite and the adsorbent can be produced reliably so as to have guaranteed properties.
A β-zeolite powder having a SiO2/Al2O3 ratio of 80 or more, which consists essentially of primary particles giving a full width at half maximum of reflection peak for (h,k,l)=(3,0,2) of 2θ=0.5° or smaller when the X-ray diffraction pattern is obtained from an X-ray diffractometer using Cu=Kα as the X-ray source, said powder having a specific surface area retention of at least 59% after exposure to a steam-containing atmosphere having a temperature of 1000° C. for 4 hours, wherein said primary particles have at least one angular portion.
Dependencies are inferred from the claim text.