GB510256A - Improvements in or relating to carbon articles and methods of producing the same - Google Patents

Abstract

510,256. Making carbon articles. WILLMORE, C. B. Jan. 29, 1938, No. 2903. Convention date, Jan. 30, 1937. [Class 90] Carbon articles, such as electrodes, are obtained by mixing in the cold, particles of carbonaceous material, a finely divided solid binder which will carbonize to give an electrically conducting residue, and a solvent for binder sufficient to act on the surface of the particles but insufficient to soften the binder and to destroy the granular nature of the mixture. 'The resulting mixture is then shaped under pressure without the use of heat. The temperatures used, e.g., 5-40‹C. are insufficient to soften the binder, although heated moulds may be used. The carbonaceous material comprises graphite, petroleum, coke, calcined anthracite, pitch coke or metallurgical coke and the binder melts between 60‹ and 200‹C., e.g. coal tar pitch; petroleum pitch, resin or synthetic resins. Suitable solvents include creosote oil, benzol, pyridine, nitrobenzene, -o-nitrotoluene, furfural, acetone, turpentine, aniline, butyls alcohol, naphthae, chlorinated compounds such as carbon tetrachloride, monochlorbenzene or dichlorpentane, or mixtures. 'The solvent is preferably added to the mixture of carbon and binder while stirring and the product then moulded under a pressure of 5,000-15,000 lbs/sq. in. and are finally baked in the usual manner. Other articles which may be made include generator brushes, and linings for various types of vessels. According to an example, "green" electrodes having a density of 1.45 were made from a mix of 1,360 lbs. coke aggregate, 240 ground coal tar pitch and 4.8 gallons of dichlorpentane moulded under a pressure of 6,250 lbs/sq. in. 'They were then baked at 1,000‹C. for about 24 hours. The density of the final electrodes was about 1.40.