Processes for preparing mono-dispersed particles
    1.
    发明授权
    Processes for preparing mono-dispersed particles 失效
    制备单分散颗粒的方法

    公开(公告)号:US4925704A

    公开(公告)日:1990-05-15

    申请号:US206863

    申请日:1988-06-13

    摘要: In a process for preparing spherical particles of a metal oxide or hydroxide having a particle size of from 0.1 to 10 .mu.m by adding a corresponding metal alkoxide to a dispersion of water-alcohol system having dispersed therein a metal oxide or hydroxide as a seed, under alkaline conditions and allowing a decomposition product from said metal alkoxide to attach onto said seed to effect particle growth of the seed, the improvement which comprises maintaining said dispersion at a substantially constant pH within the range between 10 and 13 during the addition of the metal alkoxide to said dispersion and the subsequent particle growth of the seed, thereby to prepare mono-dispersed particles substantially free from particle aggregation having a sharp particle size distribution of a standard deviation of not greater than 0.5. The white particles so prepared may be, after separation, heat treated to provide black particles. The white or black particles may be coated with a synthetic resin in the surface. The products are useful particularly as spacers for liquid crystal display devices.

    摘要翻译: 在通过向其中分散有金属氧化物或氢氧化物作为种子的水 - 醇体系的分散体中加入相应的金属醇盐来制备粒径为0.1至10μm的金属氧化物或氢氧化物的球形颗粒的方法中, 在碱性条件下并允许来自所述金属醇盐的分解产物附着在所述种子上以实现种子的颗粒生长,其改进包括在添加金属期间将所述分散体保持在10至13之间的基本恒定的pH值在10和13之间的范围内 所述分散体和随后的种子颗粒生长,从而制备基本上不具有标准偏差不大于0.5的尖锐粒度分布的颗粒聚集的单分散颗粒。 如此制备的白色颗粒可以在分离后进行热处理以提供黑色颗粒。 白色或黑色颗粒可以在表面上涂覆合成树脂。 该产品特别用作液晶显示装置的间隔物。