| 摘要 |
<p>1,250,684. Porcelain compositions. NIPPON GAISHI K.K. 25 Sept., 1969 [21 Nov., 1968], No. 47197/69. Heading C1J. Crack resistant porcelain for electric insulators is made by shaping, drying and firing at 1180-1350‹ C. a body consisting of (a) 30- 50 wt. per cent of feldspathic material, 30-60% clay and 10-30% quartz, the quartz consisting of less than 2% of particles with an effective diameter smaller than 10 microns and more than 97% of particles with an effective diameter smaller than 50 microns; (b) 20-40% feldspathic material, 5-25% quartz of the above specified particle size, 20-55% clay and 10- 45% alumina; or (c) 20-40% feldspathic material, less than 25% quartz (which can be of the above specified particle size), 20-55% clay and 10-60% calcined bauxite, the bauxite consisting of less than 60% of particles with an effective diameter smaller than 10 microns and more than 97% of particles with an effective diameter smaller than 60 microns. Suitable clays are kaolin, which can contain some quartz, china clay and ball clay. The quartz used can be a siliceous sand.</p> |
