Tokyo Shibaura Denki Kabushiki Kaisha

Mitsui Toatsu Chemicals, Incorporated

Shigeru Takahashi

Iwao Ohshima

Akihiro Yamaguchi

Shoji Tamai

Shigeyuki Shishido

Akira Ibi

Shinichi Menju

Mizuho Yamashita

Takushi Sato

Masaki Honda

Hisai Nakajima

This invention relates to a polyimide powder in use for adhesion and/or coat forming and to a method of preparing said powder, wherein polyamic-acid is chemically imidized which is obtained by reacting tetracarboxylic acid dianhydride with diamine in organic solvents. This invention further relates to a method for adhesion and coat forming by using said polyimide powder. This invention still further relates to a method for preparing prepreg by using said polyimide powder, and a method for adhesion and preparing molded laminates by using said prepreg.

Polyimide adhesives, coats and prepreg

In an arrester comprising a characteristic element made up of a stack of a plurality of metal oxide resistors, parallelly connected capacitor and a linear resistor are connected between the characteristic element and ground, and voltage drop across the linear resistor is used to light a neon lamp or to operate an alarm device for detecting deterioration of the characteristic element. To protect the capacitor and the linear resistor at the time when the arrester operates, a nonlinear resistor may be connected in parallel with the capacitor and the linear resistor.

Apparatus for detecting degradation of characteristics of arresters

In a protective gap device for protecting a circuit breaker, there are provided a cylindrical metalic shell, a high voltage electrode unit, and a low voltage electrode unit. The high and low voltage electrode units are respectively provided with a main electrode, a trigger electrode, and a cylindrical electrode plate, each of the trigger electrodes having a rod-shaped electrode so as to form a trigger gap between the main electrode and the trigger electrode.

Protective gap devices for protecting circuit breakers

Growing community of inventors

Yokohama, Japan

Shigeru Takahashi