GB1431909A - Treatment of carbon articles - Google Patents

Abstract

1431909 Coating carbon articles by pyrolytic deposition KUREHA KAGAKU KOGYO KK and TOYO BOSEKI KK 15 March 1973 [15 March 1972] 12648/73 Heading ClA [Also in Division D1] The mechanical strength, oxidation resistance and flexibility of a carbon article, e.g. a fibre or tape is improved by pyrolytically depositing on the article a product containing carbon, and based on the weight of carbon, 1% to 20% by weight of phosphorus, and then thermally treating the coated carbon article at a temperature of 1500‹ to 2000‹ C. in a non-oxidizing atmosphere, the pyrolytic product being formed by pyrolysing, the presence of the article, a vaporizable starting material containing carbon and phosphorus in suitable proportions, the carbon being present in the material as an organic compound and the phosphorus being present as the element, as an inorganic compound or as an organic phosphorus compound. The final heat treatment may be carried out for 0À2 seconds to 30 mins. Carbon may be present in the starting materials as an organic compound having at least two aromatic rings and a vapour pressure greater than 5 mm. Hg at 490‹ C. The phosphorus may be present as an organic phosphorus compound containing at least one aromatic ring, e.g. triphenyl phosphine, or triphenyl phosphate, and this compound may serve as the sole source of carbon and phosphorus. Before coating, the surface of the carbon article may be smoothed by passage through an electrodeless discharge type argon plasma torch.