Kabushiki Kaisha Toyota Chuo Kenkyusho

Nippondenso Co., Ltd.

Yoshiharu Hirose

Akane Okada

Osami Kamigaito

Haruo Doi

Toshio Kurauchi

Tohru Shiga

Takashi Ohta

Naoto Miwa

Norio Sato

Tatsumi Hioki

Masami Ouki

Kazuyuki Ito

Nobuyuki Yamamoto

A variable-modulus material is composed of a polymer whose constituent unit is a thiophene or pyrrole molecule having from one to three C.sub.4-12 alkyl side chains, or a copolymer whose constituent unit is the thiophene or pyrrole molecule and which includes in a main chain thereof a conjugated compound with a K-electron bond directly bonded to the above molecule, and at least one additive (in an amount of 0.5-20 wt % of said polymer) selected from halogens, protonic acids, and transition metal halides. It greatly decreases in modulus upon application of an electric field as low as 5-150 V/mm and restores its original modulus upon removal of the electric field. It is suitable for use as vibration dampers and shock absorbers.

Variable-modulus material

A material with variable viscoelasticity is composed of an electrically insulating polymeric material, and fine particles dispersed therein and capable of electric polarization under an applied electric field. The particles may, for example, be of a conjugated and unsaturated organic compound, a polyelectrolyte, or an organometallic complex salt. The material is capable of a reversible change of viscoelasticity depending on the intensity of the applied electric field.

Material with variable viscoelasticity

A process for producing a cordierite ceramic product comprises blending a starting cordierite composition which comprises:

Process for producing cordierite ceramic products

Semiconductive barium titanate having a positive temperature coefficient of resistance comprises a barium titanate semiconductor including barium titanate and a small quantity of a doping element, and at least one additive selected from among silicon nitride, titanium nitride, zirconium nitride and silicon carbide. The semiconductive barium titanate of this invention has a sharp rise in the variation of specific resistivity with temperature change and a large specific resistivity ratio in the PTC temperature region, and can be produced with high reproducibility, since a widely differing quantity of the doping element can be effectively added to barium titanate.

Semiconductive barium titanate

Growing community of inventors

Nagoya, Japan

Yoshiharu Hirose