| 摘要 |
PURPOSE:To readily remove a binder from a molded article by using a thermoplastic resin hydrolyzable with an alkali ion or an enzyme as the binder. CONSTITUTION:A composition for injection molding comprising raw material powder of ceramic or metal having 0.1-30mum particle diameter and a thermoplastic resin (e.g. acrylic resin) hydrolyzable with an alkali ion (e.g. sodium) or an enzyme (e.g. esterase) and then the thermoplastic resin is removed by the alkali or the enzyme. For example, 100 pts.wt. of beta-alumina is blended with 12 pts.wt. of ethyl acrylate by a pressure kneader and granulated by a pelletizer to give a raw material for injection molding. Then the molded article is immersed in 10% aqueous solution of sodium orthosilicate kept at about 50 deg.C for about 5 hours. Then the molded article is sufficiently washed with water. The defatted material is heated at 100 deg.C/hour rate of heating up to 500 deg.C in air to remove the residual binder. Successively the defatted molded article is heated at 300 deg.C/hour rate of heating up to 1,400 deg.C to give a sintered material. |
