| 摘要 |
<p>1457931 Ceramic insulating layer NIPPONDENSO CO Ltd 8 March 1974 [10 March 1973 11 April 1973 11 Jan 1974] 10559/74 Heading C1J [Also in Divisions B1 F1 and F2] A ceramic insulating layer is formed by firing a slurry prepared by mixing aqueous phosphate solution with a material consisting of 20-70% silica, 15-80% alumina and 0-30% magnesium oxide, e.g. cordierite, mullite, sillimanite or kaolin. The phosphate may be aluminium or zinc primary phosphate, or magnesium tetrahydrogen phosphate. Before firing, the slurry may be effervesced by adding acid and a metal or carbonate optionally with the addition of a bubble stabilizer such as corn starch, yolk, cellulose acetate, dry blood; or burnable substances may be added that lose volume on firing; or light weight aggregates such as effervesced pearlite or obsidian may be added.</p> |
