Carbon--carbon composites containing poorly graphitizing pitch as a binder and/or impregnant
AssigneeUCAR Carbon Technology Corporation
InventorsIrwin Charles Lewis, Ronald Albert Howard
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Abstract
A unitary composite structure having improved flexural strength and a reduced coefficient of thermal expansion comprising a heterogeneous combination of a carbonaceous reinforcing material interbonded with a matrix material, wherein the said matrix material is a poorly graphitizing carbonaceous pitch containing polymerized and cross-linked aromatic components is disclosed. Graphite electrodes comprised of the poorly graphitized pitch matrix material acting as a binder and/or an impregnant are also disclosed. Processes for the preparation of the poorly graphitizing pitch, the composite structure, and particularly the graphite electrodes are disclosed as well.
Claims4
A process for the production of a unitary composite structure comprising a heterogeneous combination of carbonaceous reinforcing material interbonded with a matrix material comprising:
- (a) providing the matrix material by treating a tar or a pitch having aromatic components with a cross-linking agent to polymerize and cross-link the aromatic components to the extent that the pitch becomes poorly graphitizing and forms substantially no mesophase pitch or forms mesophase pitch having a domain size of less than about 30.mu.;
- (b) combining the poorly graphitizing matrix pitch material with reinforcing material;
- and then
- (c) subjecting the combination of reinforcing material and matrix material to carbonization conditions to form the interbonded unitary composite structure, wherein the tar or pitch is polymerized and cross-linked by being contacted with at least one Lewis acid selected from the group consisting of FeCl.sub.3, SnCl.sub.2, SnCl.sub.4, FeBr.sub.3, I.sub.2, ZnCl.sub.2, SbCl.sub.3, SbCl.sub.5, CoCl.sub.2, BF.sub.3 and combinations thereof.
A unitary composite structure comprising a heterogeneous combination of a carbonaceous reinforcing material interbonded with a matrix material, said matrix material being a carbonaceous pitch cross-linked with oxygen containing polymerized and cross-linked aromatic components thereof which have been cross-linked to the extent that the pitch is poorly graphitizing and has formed substantially no mesophase pitch or contains mesophase pitch having a domain size of less than about 30.mu..
Dependencies are inferred from the claim text.