| 摘要 |
Described is a method for the manufacture of a pastel-white, highly opaque, micro-particle rutile pigment from a crude rutile, synrutile or from a slag-like rutile-type precursor characteristic for traditional titanium dioxide production from processing ilmenite into titanium dioxide. This method distinguishes itself in that the starter material in form of the crude rutile, synrutile or the slag-like rutile-type precursor is ground down in several stages in high efficiency mills without leaving any significant metallic fines, to a particle size of approximately 200 to 600 nm, whereby initially a dry pre-grinding step is performed and thereafter with high recorded grinding output a wet grinding step is performed in a final grinding phase. The ground-down product is dried and the obtained rutile pigment is calcinated in finely distributed form at temperatures between 790 and 1050° C. The invention thus also concerns-a pastel-white, micro-particle and highly opaque rutile pigment attainable according to this method with reduced grinding-stable photo-activity and a grain size distribution of particle diameters ranging between 150 and 100 nm and with mono- or oligo-modal frequency distribution with a principal maximum of the distribution curve between 200 and 600 nm. It presents a particularly fine brightness, purity of color and covering capability with concurrently to a minimum reduced photo-activity and it is suitable for being beneficially worked into polymer materials, construction materials, ceramic lamination materials, papers and pressed laminates, varnishes, paints and print colors.
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