| 摘要 |
PURPOSE:To produce a porous structure of ceramics with high density and strength and with high porosity and a labyrinthine pattern of pores by using r-lithium aluminate of a specific grain diameter as a sintered inorganic substance and by specifying the addition of wood pulp to within a certain limit. CONSTITUTION:As an inorganic material is used r-lithium aluminate which is produced by the following process: lithium hydroxide and/or lithium chloride and gamma-Al2O3 are calcined at 1,000 deg.C for more than 1hr and cooled down, and this calcined product is then ground into pieces with a ball mill until the average diameter of grains will be less than 1mu. As a fiber material is added a certain amount of wood pulp which is by weight 3-15% of the total dry weight of uncalcined sheet-like material. And this mixed water base slurry is adjusted to be 7 in pH with an inorganic acid or alkali water solution, and then condensed and prepared to a sheet by adding a coagulating agent and a surface active agent. As for calcination, the temperature is raised from room temperature by 30-80 deg.C/H and kept at 500-700 deg.C for 1-3hr, and then raised again by 100- 300 deg.C/H and held at 1,000-1,300 deg.C for 1-3hr. |
