Tosoh Corporation

Nobuhiro Ogawa

Takashi Mori

Kazuaki Yamamoto

Keiji Itabashi

Hajime Funakoshi

Atsushi Harada

Yoshinori Shirakura

Shunsuke Yatsunami

Kimitaka Kuma

Ryoji Yoshimura

Tetsushi Iwamoto

Takashi Mouri

Chikara Uema

A novel heat-resistant low-silica zeolite, an industrial production process, and uses of the low-silica zeolite are provided. The heat-resistant low-silica zeolite contains Si and Al in a molar ratio of SiO.sub.2 /Al.sub.2 O.sub.3 ranging from 1.9 to 2.1, and has sodium and/or potassium as metal cation, wherein the low-silica zeolite contains low-silica faujasite type zeolite at a content of not lower than 88%, and has a thermal decomposition temperature ranging from 870.degree. C. to 900.degree. C. in the air. The process for producing the heat-resistant low-silica zeolite comprises mixing a solution containing an aluminate with another solution containing a silicate, allowing the resulting mixture to gel, and aging the resulting gel, at the temperature of from 0.degree. C. to 60.degree. C., to prepare a slurry having a viscosity ranging from 10 to 10000 cp and containing amorphous aluminosilicate having a specific surface area of not less than 10 m.sup.2 /g with an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio ranging from 1.9 to 2.1; and subsequently crystallizing the aluminosilicate. The low-silica zeolite ion-exchanged with lithium or an alkaline earth metal is useful for gas separation.

Heat-resistant low-silica zeolite, and process for production and

A crystalline zeolite X adsorbent comprising a crystalline zeolite X having an SiO.sub.2 /A.sub.2 O.sub.3 molar ratio of not larger than 3.0, where lithium cations associated with an AlO.sub.2 tetrahedron unit are 80 to less than 88 mol % of the total cations and the content of alkaline earth metal cations is from 0.5 to less than 4.6 mo % is produced by ion-exchanging with lithium cations at least 90 mol % of the cations associated with an Al.sub.2 O.sub.3 tetrahedron unit of a crystalline zeolite X having an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of not larger than 3.0, ion-exchanging the crystalline zeolite X again with an aqueous solution of mixed salts of an alkali metal salt and an alkaline earth metal salt to decrease the lithium cations associated with the AlO.sub.2 tetrahedron unit to 80 to less than 88 mol %, followed by washing and drying, and activating the crystalline zeolite X. The crystalline zeolite X adsorbent is used for the recovery of oxygen from air by a pressure swing adsorption method by using the crystalline zeolite adsorbent.

Adsorbent for air separation, production method thereof, and

An ITO sintered body according to the present invention has a density thereof of between 90 and 100% and a sintering particle size of between 1 and 20 .mu.m. A proportion of (In.sub.0.6 Sn.sub.0.4).sub.2 O.sub.3 in the ITO sintered body is 10% or below. Such an ITO sintered body is manufactured by mixing an indium oxide powder, whose BET surface area is between 15 and 30 m.sup.2 /g, a BET size/a crystallite size is 2 or below, and an average primary particle size is between 0.03 and 0.1 .mu.m, with tin oxide whose BET surface area is 3 m.sup.2 /g or below, and then by sintering the mixture.

Ito sintered body and method of manufacturing the same

An electroconductive zinc oxide sintered body composed of sintered particles fusion-bonded in the grain boundaries thereof; which has a sintered density of from 5 to 5.5 g/cm.sup.3 ; and which does not substantially contain closed cells isolated from the outside in the interior of the sintered body. The electroconductive zinc oxide sintered body is prepared by sintering a mixture of an oxide of an element having a positive valency of at least 3 and zinc oxide in the presence of water at a temperature of at least 1,300.degree. C. The electroconductive zinc oxide sintered body is used as a sputtering target for the preparation of a low resistance, transparent electroconductive film.

Zinc oxide sintered body, and preparation process and use thereof

An indium oxide powder or indium oxide/tin oxide powder having an average primary particle diameter of 1 to 0.01 .mu.m, a BET surface area of 15 to 50 m.sup.2 /g, and a specific surface area of 2 to 5 m.sup.2 /g as determined from the particle diameter distribution. The mixed powder is prepared by coprecipitating an indium- and tin-containing salt from a solution containing indium and tin, calcining the salt, and pulverizing the calcined product using a specific vibrating pulverizer. A sintered body, prepared by sintering the indium oxide/tin oxide powder, has a density of at least 5.3 g/cm.sup.3, a specific resistance of 2.times.10.sup.-3 to 2.times.10.sup.-4 .OMEGA.-cm, and an average grain diameter of 5 to 15 .mu.m.

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Ichikawa, Japan

Nobuhiro Ogawa