| 摘要 |
1,137,159. Cellular refractories. PPG INDUSTRIES Inc. 20 Oct., 1966 [21 Oct., 1965], No. 46975/66. Heading C1J. An organic foam containing a refractory is obtained by heating a composition comprising an organic isocyanate terminated prepolymer resin, a catalyst for isocyanurate formation, a blowing agent, a pulverulent inorganic refractory and a flux of a Group 1 or 2 metal compound, e.g. Na bicarbonate or silicate. Blowing agent also includes beating in air or a gas or introducing gas under pressure into the polymerizable mixture. The foam can be heated to char the organic portion or to eliminate it, leaving a refractory foam which can be impregnated with, e.g. synthetic resins. Specified refractories are SiO 2 , Al 2 O 3 , ZrO 2 , TiO 2 , ThO 2 , Sb 2 O 3 , WO 3 , carbides of W and B, B, Ca and Mg ZrO 3 and V 2 O 5 . Fibres, e.g. asbestos, glass, steel wire, carbonaceous, zirconia and quartz fibres are optional.
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