Electrically conductive compositions
AssigneeDenki Kagaku Kogyo Kabushiki Kaisha
InventorsYuji Miyazaki, Akio Nishijima, Kiyomiki Kawanami
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Abstract
An electrically conductive composition comprises 100 parts by weight of synthetic resin and/or rubber, 5 to 100 parts by weight of a conductivity-affording agent, and 1 to 100 parts by weight of carbon fiber. The agent used is carbon or acetylene black having resistivity of no higher than 0.3 .OMEGA.cm, a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m.sup.2 /g, which is obtained by continuous thermal cracking of acethlene gas by a mixed gas flow of oxygen-containing gas and steam in the presence or absence of unsaturated hydrocarbons.
Claims14
Acetylene black having an electrical resistivity of no higher than 0.03 .OMEGA.cm at a pressure of 50 kg/cm.sup.2, a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m.sup.2 /g, which is obtained by continuous thermal cracking at a temperature of no less than 800.degree. C. of acetylene gas by a mixed gas flow of oxygen-containing gas and dry steam, said oxygen-containing gas having the relation a +(b/2 )<1 in molar units, where 0<a<1 and 0<b<2 with respect to steam b as pure oxygen a.
The method of preparing an acetylene black having an electrical resistivity of no more than 0.03 .OMEGA.cm at a pressure of 50 kg/cm.sup.2, a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m.sup.2 /g, comprising the steps of:
- (a) thermally cracking at a temperature of no less than 800.degree. C. acetylene gas with a mixed gas flow of an oxygen-containing gas and dry steam, said oxygen-containing gas having the relation a+(b/2)<1 in molar units where 0<a<1 and 0<b<2 with respect to steam b and pure oxygen a.
Dependencies are inferred from the claim text.