ZnO压敏陶瓷制造用有机原材料的选择及优化应用

Selection and Optimized Application of Organic Raw Materials for ZnO Varistor Manufacturing

根据不同有机原料的理化性能、主要用途,并结合实际生产应用认为,合理选择有机原料及使用量,对制备ZnO与添加剂料浆成分的均匀性,喷雾造粒粉料的物理性状及坯体成型的均一性都有较大的影响,从而影响耐受冲击能量及其稳定性。得出:结合剂一般选用高醇解度的聚乙烯醇(PVA),加入量以0.5%～0.8%为宜,且尽可能减少PVA的添加量;分散剂应选择具有润滑性的分散剂,这对制造较大直径的电阻片是很有利的;消泡剂应选择易于在溶液表面铺展的消泡剂,如磷酸三丁酯;纯水电阻率不应小于1 MΩ·cm(25℃)。

Selection and rational process matching of organic raw materials for manufacturing ZnO varistors such as linking agent, dispersant, bubble-cease agent, plasticizer, lubricant, etc.. Based on physic-chemical properties and purpose of different materials and processing practice, it is considered that rational selection of organic materials and their dose have considerable influence to homogeneity of ZnO and additive slurry, physical mechanism of spray-dried powder and homogeneity of pressed disc body, and thus to electric properties of varistor, especial the surge discharge capacity and stability. It is concluded that polyvinyl alcohol （PVA） of high alcoholysis should be chosen as linker, with possibly lowest dose of about 0.5%～0.8%, lubricating dispersant would be advantageous for larger varistor processing, a dispersed bubble-cease agent such as phosphonate tri-ester should be selected, and the pure water should have resistivity not less than 1 MΩ·cm （25℃）.