| abstract |
1343669 Composite carbon fibre-containing articles KUREHA KAGAKU KOGYO KK 29 Dec 1971 [29 Dec 1970 (2)] 60432/71 Heading C1A Composite articles are made by mixing with an organic binding material having a carbonization yield of more than 10%, a heat-treated stabilized organic fibre having an average diameter of less than 40 microns, a ratio between fibre length and diameter of more than 5, a hydrogen/carbon atomic ratio of from 0À25 to 0À8, an ether-bonded type oxygen content of from 3 to 15%, a carbonization yield of from 50 to 92% and a linear shrinkage of from 4 to 25% at a temperature of 1000 C., shaping the mix, and then heat-treating it under carbonization or graphitization conditions. Inorganic or carbonaceous aggregate may be mixed with the stabilized fibre prior to shaping. The fibre heattreated may be of cellulose, polyacrylonitrile, polyvinyl alcohol, lignin, phenol resin, furfural resin, or pitch. The binder material may be coal tar or pitch, petroleum tar or pitch, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, a phenol resin, an epoxy resin, a diarylphthalate, a furfural resin, or an unsaturated polyester resin. The aggregate may be a refractory clay, sand, dolomite, siliceous stone, magnesia, alumina, zirconium oxide, silicon dioxide, silicon carbide, carbon or graphite. The fibres may be in the form of a sheet of paper, felt, or cloth. The product may be in the form of a graphitic plate, tube, electrode, an alumina or graphitic brick, or a laminate. The heat-stabilized fibres are made by heattreating an organic fibre at a temperature of from room temperature to 350 C. in an oxidizing atmosphere. In example I, a melt-spun pitch fibre was heat-treated in an oxidizing gas containing 3% by volume of nitrogen dioxide, by raising the temperature to 250 C. by incremental temperature rises of 1À5 C. per minute. In Example V the fibre of Example 1 was further heat-treated at a temperature of 300 C. for 60 minutes in ammonia gas. In Example VIII, the infusible fibre is made from a polyacrylonitrile fibre having a diameter of 15 microns by heattreatment for 5 hours at a temperature of 220- 240 C. in air containing 3% by volume of NO 2 . |