Method for manufacturing graphite whiskers using condensed polycyclic hydrocarbons

Claim 1

A method for manufacturing graphite whiskers having a diameter of from 1 to 50 microns, a tensile strength of at least 1,000 kg/mm 2 and a modulus of elasticity of at least 5 × 10 4 kg/mm 2 , which comprises the steps of gasifying one or more liquefied organic compounds having a condensed polycyclic structure of substantially two to five benzene rings, the atomic ratio of H/C thereof being 1 at most; mixing the gasified substance derived from one part by volume of the liquefied organic compound with 500 to 5000 parts by volume of an inert gas mixed with 0.1 to 5 parts by volume of an active gas selected from the group consisting of carbon monoxide, carbon dioxide and water vapor; passing the resulting gaseous mixture at a substantially atmospheric pressure through a reaction furnace containing therein a heat-resistant substrate to deposit thereon thermally cracked carbon nuclei at a temperature of from 700° to about 890° C. for a period of at least 5 minutes, followed by 900° to 1200° C. to obtain precursory carbon whiskers at a growing velocity of at least 0.5 mm per minute; and graphitizing the precursory carbon whiskers in another furnace at a temperature of from 2700° to 3000° C. for a period of from 1 to 10 minutes in an atmosphere of inert gas.

Claim 2

A method for manufacturing graphite whiskers having a diameter of from 1 to 50 microns, a tensile strength of at least 1,000 kg/mm 2 and a modulus of elasticity of at least 5 × 10 4 kg/mm 2 , which comprises the steps of gasifying one or more liquefied organic compounds having a condensed polycyclic structure of substantially two to five benzene rings, the atomic ratio of H/C thereof being 1 at most; mixing the gasified substance derived from one part by volume of the liquefied organic compound with 500 to 5000 parts by volume of an inert gas mixed with 0.1 to 5 parts by volume of an active gas selected from the group consisting of carbon monoxide, carbon dioxide and water vapor; passing the resulting gaseous mixture at a substantially atmospheric pressure through a reaction furnace containing therein a heat-resistant substrate to deposit thereon thermally cracked carbon nuclei at a temperature of from 700° to about 890° C. for a period of at least 5 minutes, followed by 900° to 1200° C. to obtain precursory carbon whiskers at a growing velocity of at least 0.5 mm per minute; and graphitizing the precursory carbon whiskers in another furnace at a temperature of from 2700° to 3000° C. for a period of from 1 to 10 minutes in an atmosphere of inert gas.