| 摘要 |
<p>1293004 Making metal oxide, nitride or carbide articles UNION CARBIDE CORP 17 Feb 1970 [17 Feb 1969] 7559/70 Heading C1A [Also in Divisions C7 and D1] In a "relic" process (see Specifications 1,144,033, 1,159,210 and 1,177,782), in which cellulosic fibres, textiles or shaped articles are impregnated with metal (including Si and B) compounds and then converted by heating under appropriate conditions into articles having the form of the cellulosic precursors but composed of metal oxides, carbides or nitrides, the efficiency of the impregnation step is improved by previously or concurrently contacting the precursor with an alkylenediamine to swell it. Examples describe the impregnation of rayon yarn with ZrOCl 2 is aqueous solution after preswelling of the yarn in ethylenediamine or ethylenediamine-water. A further example describes pre-swelling of rayon yarn with ethylenediamine-water, impregnation with ammonium pentaborate dissolved in ethylenediaminewater and pyrolysis of the product in ammonia to yield boron nitride yarn. Other suitable metals include A1, Ta, Si, Ca, Cu, Ag, U, W, Ni, Zn, Fe, Cr, Nb, Ti, Hf, Th, Zr, V, Mo and Y.</p> |
