Mitsubishi Denki Kabushiki Kaisha

Takashi Shirazawa

Takeo Inoue

Tadaki Murakami

Kazuharu Kato

Mica-containing ceramic composite having excellent characteristics such as capability of machining work, a small thermal expansion coefficient, high heat-shock resistant temperature difference as well as high heat deformation temperature, is prepared by: a) preparing powder mixture by blending 20 to 50% by weight of mica powder, 15 to 40% by weight of zinc oxide powder, 10 to 20% by weight of silica powder, 8 to 20% by weight of boric acid powder, and 4 to 20% by weight of cordierite powder; b) heating the powder mixture at a temperature of from 940.degree. C. to 1,050.degree. C. to prepare baked product; c) pulverizing the baked product into very fine powder to thereby obtain a shaping material; d) adding an organic binder to the shaping material to prepare a shaping composition; and e) shaping the shaping composition into a shaped body and heating a shaped body at a temperature ranging from 940.degree. C. to 1,050.degree. C. with simultaneous application of pressure to the shaped body to render the same into a baked body.

Process for preparing mica-containing ceramic composite

A corrosion-resistant metal pipe, and a process for producing the same, such as may be used in an electrode unit for electrically heating underground hydrocarbon resources or for conveying corrosive materials. The pipe may be produced in any desired length. In one embodiment, the corrosion-resistant pipe includes a base pipe element composed of at least two corrosion-resistant pipes joined by welding. The two pipes are stripped at adjacent ends of a first coat made of a glass-mica molded body formed on both inner and outer surfaces of the pipe. A plurality of communication holes are formed in the joint provided by welding the pipes. A second coat formed of a glass-mica molded body is then provided on both inner and outer surfaces of the joint with the second coat continuous with the first coat.

Corrosion resistant metal pipe with electrode for oil wells

An insulated pipe joint and a method for producing the joint in which first and second tubular portions are joined through an insulating member disposed in a gap between the first and second tubular members. The first tubular member has a flange portion at one end thereof while the second tubular member has a cap portion which accommodates the flange portion of the first tubular member with the gap being formed between the cap and flange portions. The insulating member disposed in the gap hermetically couples the first and second tubular members while electrically insulating them from one another.

Method for producing insulated pipe joint

An insulated joint and a method for producing the joint in which first and second tubular members are joined together with an insulating member disposed in the gap therebetween. The first tubular member includes a cylindrical body with an outer circumferential portion having a larger internal diameter than the external diameter of the cylindrical body while the second tubular member has the same internal and external diameters as those of the cylindrical body of the first tubular member. At least a portion of the second tubular member is fitted in the outer circumferential portion of the first tubular member with a gap therebetween. An insulating member is disposed in the gap to hermetically couple the first and second tubular members while insulating them from each other.

Growing community of inventors

Hyogo, Japan

Takashi Shirazawa