| 摘要 |
Slurry comprises: (a) from 50 to 80% by weight, of refractory particles having an average particle size of from 0.5 mu m to 150 mu m; (b) from 5 to 35% by weight, of aluminum oxide particles having an average particle diameter of less than 300 nm; and (c) from 5 to 35% by weight of water, with a pH of from 5 to 12. Independent claims are: (1) a method for producing the slurry, characterized in that an aqueous dispersion which contains (a) aluminum oxide particles having an average particle diameter of less than 300 nm as solid; and (b) has a content of aluminum oxide particles of more than 15% by weight; and has (c) a pH of from 5 to 12, is admixed with (b) refractory particles having an average particle size of from 0.5 mu m to 150 mu m; and (d) if appropriate, additives; (2) an aqueous dispersion of aluminum oxide particles, characterized in that: (a) the aluminum oxide particles have an average particle diameter of less than 300 nm; (b) the content of aluminum oxide particles is more than 15% by weight; (c) the dispersion additionally contains one or more additives selected from antifoams, wetting agents, polymers, polyphosphates, metal-organic compounds and antibacterial agents; and (d) the dispersion contains a buffer system and has a pH of from 5 to 12; (3) a process for producing a casting mold comprising: (a) dipping of a preshaped meltable model into the slurry; (b) coating of the surface of the model which is covered with the slurry by sanding with coarse, refractory particles having an average particle size of from not > 50 mu m to 1000 mu m; and (c) drying of the coated surface, where the steps (a) to (c) are repeated as often as desired until the number of coating layers required for the casting mold has been reached; and (4) a casting mold produced by a process. |
