多层陶瓷电容器（MLCC）端电极用超细铜粉的制备

【作者】 王崇国；

【导师】 周康根；

【作者基本信息】 中南大学 ， 环境工程， 2007， 硕士

【摘要】 粒度控制、形貌控制和分散状况是多层陶瓷电容器（MLCC）端电极用超细铜粉制备的研究重点。本研究采用两步液相还原法制备超细铜粉，研究包括两个部分：两步加肼法制备超细铜粉和晶种长大法制备超细铜粉。超细铜粉样品采用扫描电子显微镜（SEM）、X射线衍射（XRD）、热重分析（TGA）表征其性质。两步加肼法成功地制备了平均粒径在1.4～2.7μm的球形超细铜粉。考察了葡萄糖预还原、反应温度、水合肼添加方式与添加量以及添加剂聚乙烯吡咯烷酮（PVP）的用量等因素对超细铜粉粒度和形貌的影响。实验结果表明，葡萄糖预还原和分步添加水合肼均有利于超细铜粉的均匀长大；改变两步水合肼添加量的比例能在一定程度上调控铜粉的粒径；适量PVP能有效防止超细铜粉粒子的团聚。根据实验结果建议采用的最佳工艺条件是：反应温度84℃下，分步添加水合肼，前后两步水合肼添加量的比例=1：5，PVP的添加比例为CuSO₄·5H₂O／PVP=50（质量比）。采用晶种长大法制得了平均粒径在2.2～3.1μm的超细铜粉，实验表明铜粉能在晶种的基础上显著长大（晶种的平均粒径为1.5μm）。实验考察了水合肼的用量、晶种用量以及反应温度等因素对超细铜粉粒度、粒度分布的影响。实验结果表明，水合肼的用量和反应温度对Cu₂O的还原程度有显著影响，适宜的水合肼用量为Cu₂O／肼=1.5（质量比），反应的适宜温度为60℃；通过改变晶种的用量能有效控制超细铜粉的粒径，在适当的晶种用量下可以得到平均粒径在2.2～2.7μm之间的超细铜粉。更多还原

【Abstract】 The main technical problems of ultrafine copper powders for MLCCare particle size controlling, morphology controlling and dispersibility. Inthis work, ultrafine copper powders were prepared by two stepsreduction process of liquid phase. And the research includes two parts:preparation of copper powders by two steps hydrazine hydrate addition:preparation of copper powder by crystal species generation. The copperparticles synthesized were characterized by SEM、XRD and TGA.Spherical ultrafine copper powders with average particle size of1.4～2.7μm have been synthesized by two steps hydrazine hydrateaddition. The effects of glucose pre-reduction, reaction temperature,addition methods and amounts of hydrazine hydrate, and additionamount of PVP on particle size and morphology of copper powders wereinvestigated. Experiments showed that glucose pre-reduction and step bystep hydrazine hydrate addition were favorable for uniform growth ofultrafine copper powders. Changing amount of hydrazine hydrate addedin each step could control copper powders particle size in a certain extent.Appropriate amount of PVP could effectively prevent ultrafine copperpowders from agglomerating. Experiments showed that the optimμmconditions were: the reaction temperature 84℃, ratio of hydrazinehydrate amout added by the first step to the amount by the second step:1 to 5, and the proportion of PVP to CuSO₄·5H₂O 1 to 50 （mass ratio）.Ultrafine copper powders with average particle size of 2.2～3.1μmhave been synthesized by crystal seed generation. It was found thatcopper powders could obviously grow based on crystal seed （averageparticle size 1.5μm of crystal seed）. The effects of amount of hydrazinehydrate and crystal seed, reaction temperature on particle size andparticle size distribution of copper powders were investigated.Experiments showed that the reduction extent of Cu₂O were influencedremarkably by amount of hydrazine hydrate and reaction temperature.The proper proportion of Cu₂O to hydrazine hydrate was 1.5 to 1 （massratio）, the reaction temperature 60℃, the particle size of ultrafine copper powders could be effectively controlled by changing the amountof crystal seed. Ultrafine copper powders with average particle size in2.2～2.7μm were obtained by adding proper amount of the crystal seed.更多还原