Matsushita Electric Works, Ltd.

Other

Shoichi Nakamoto

Koichi Niihara

Masahiro Nawa

Tohru Sekino

Atsushi Nakahira

Keiichi Yamasaki

Koichi Takahama

Minoru Inoue

Junko Ikenaga

The present invention provides a process for forming a hydrophilic inorganic coated film on a surface of a base material, the process comprising the steps of: (1) preparing an inorganic coating composition which contains, as a major component, a silicone resin obtained by hydrolyzing and condensation-polymerizing only the tetra-functional alkoxysilane represented by the formula: Si(OR),&lsqb;wherein R represents an alkyl group having carbon atoms up to and including 7 or an aryl group&rsqb;, and has a total solid content of not more than 5% by weight; (2) applying the inorganic coating composition to a surface of the base material to form a coated layer; and (3) drying and curing the coated layer to form a cured coated film having a thickness of 0.01 to 0.5 &mgr;m. The hydrophilic inorganic coated film formed by the process of the present invention is highly hydrophilic just after the film is formed, even in the case that it is not irradiated with ultraviolet rays.

Hydrophilic inorganic coating film and composition made from alkoxysilane and silica

A zirconia based ceramic material having improved and well-balanced mechanical strength and toughness consists essentially of 0.5 to 50 vol % of Al.sub.2 O.sub.3 having an average grain size of 2 .mu.m or less and the balance of a partially stabilized zirconia having an average grain size of 5 .mu.m or less. The partially stabilized zirconia consists essentially of 8 to 12 mol % of CeO.sub.2, 0.05 to 4 mol % of TiO.sub.2 and the balance of ZrO.sub.2. Fine Al.sub.2 O.sub.3 grains having an average grain size of 1 .mu.m or less are dispersed within the grains of the partially stabilized zirconia at a dispersion ratio. The dispersion ratio is defined as a ratio of the number of Al.sub.2 O.sub.3 grains dispersed within the grains of the partially stabilized zirconia relative to the number of the entire Al.sub.2 O.sub.3 grains dispersed in the ceramic material, and at least 2% in the present invention. The ceramic material can be made by the following process. A first constituent formed of the partially stabilized zirconia is mixed with a second constituent formed of Al.sub.2 O.sub.3 to obtain a mixture. The mixture is molded into a desired shape, and then sintered in the air under an atmospheric pressure to obtain the ceramic material.

Process of making zirconia based ceramic material

A ZrO.sub.2 based ceramic material having excellent mechanical strength and fracture toughness comprises a first phase of ZrO.sub.2 grains containing CeO.sub.2 as a stabilizer and having an average grain size of 5 .mu.m or less, a second phase of Al.sub.2 O.sub.3 grains having an average grain size of 2 .mu.m or less, and a third phase of elongated crystals of a complex oxide of Al, Ce, and one of Mg and Ca. At least 90 vol % of the first phase is composed of tetragonal ZrO.sub.2. An aluminum (Al) content in the ceramic material is determined such that when Al of the complex oxide is converted to Al.sub.2 O.sub.3, a total amount of Al.sub.2 O.sub.3 in the ceramic material is within a range of 0.5 to 50 vol %. A content of the third phase in the ceramic material is determined within a range of 0.5 to 5 by area %. It is preferred that fine Al.sub.2 O.sub.3 grains having an average grain size of 1 .mu.m or less of the second phase are dispersed within the ZrO.sub.2 grains at a dispersion ratio of at least 2%.

ZrO.sub.2 based ceramic material and method of producing the same

Zirconia based ceramic material

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Neyagawa, Japan

Shoichi Nakamoto