| 摘要 |
1415089 Porous carbon bodies VALLEY CO Inc 24 May 1973 [30 May 1972] 24893/73 Heading C1A A porous carbon body is produced by (1) forming a free flowing castable fluid mix having a continuous liquid phase, the mixture being formed by mixing together; (a) a uniformly dispersible organic constituent, decomposable at a temperature in the range 250-2400‹ C. to a solid carbonaceous residue, (b) a liquid pore former capable of forming a continuous liquid phase throughout the mixture, the liquid pore former having a viscosity below 100 centipose, a low vapour pressure and a high flash point and (c) a dispersing agent able to keep the organic constituent uniformly distributed the the mixture and able to keep the liquid phase continuous and uniform; the organic constituent constituting from 5-95% by volume of the mix, the pore former and dispersing agent constituting 5-91% by volume of the mix, the blending of the mixture components being continued until the mix becomes free flowing and the organic constituent is uniformly distributed; (2) casting the mixture to shape; (3) consolidating the cast mix into a self supporting body at a temperature below the vapourizing points of all the constituents of the mixture so all the components of the mix are retained within the cast shape; (4) removing the substance still present as a continuous liquid phase from the self supporting body so as to form a system of interconnected pores and (5) heating the self supporting body to a carbonizing temperature to form the desired carbonaceous article having throughout a system of uniformly distributed interconnected pores. The organic constituent may dissolve in or be suspended in one or the other of or both of the pore former or the dispersing agent. An agent adapted to assist the consolidation of the cast body may be mixed with the pore former and the dispersing agent before the organic constituent is added. A single liquid, e.g. a glycol, may serve both as liquid pore former and dispersing agent. A filler or additive to produce desired characteristics in the final body may be added to the mix. The filler may be soluble in one of the mixture constitutents or it may be a particulate solid, e.g. carbon particles. Other fillers are silicon or its oxide, metal compounds, e.g. silicates or oxides, or metals. The silicon oxide may'be colloidal. The filler may be such as to catalyse the formation of graphite during carbonization. The mixture may be milled before casting. When the organic constituent is a polymerizable material the consolidation step may be a polymerization step. For example, the organic constituent may be furfural or furufuryl alcohol and paratoluene sulphonic acid may be incorporated as polymerization catalyst. The consolidation step may also be achieved by freezing. The consolidated body may be contacted with a gas able to react with the organic constituent and either cause cross-linking or otherwise increase the carbon yield of the constituent, before the body is carbonized. The consolidated body may be reduced to particles and re-consolidated before being carbonized. If desired, after pyrolysis the body may be reduced to particles. After carbonizing, the body may be activated by heating in CO 2 or the body may be impregnated. Suggested carbonizing conditions are a temperature of at least 250‹ C. under pressure in the range 0À1 mm.Hg. to above atmospheric in a non- oxidizing atmosphere. |
