Silica-coated barium metaborate pigments and processes of producing the same
    70.
    发明授权
    Silica-coated barium metaborate pigments and processes of producing the same 失效
    二氧化硅包覆的偏硼酸钡颜料及其制备方法

    公开(公告)号:US3033700A

    公开(公告)日:1962-05-08

    申请号:US85910459

    申请日:1959-12-14

    申请人: BUCKMAN LABOR INC

    IPC分类号: C09C1/02

    摘要: The particles of a barium metaborate pigment are coated with amorphous hydrated silica in a proportion of between 3 and 20% by weight of the pigment. The coating may be produced by commingling barium metaborate particles in aqueous medium with suitable alkali metal silicates or de-ionized preparations of such silicates, heating the mixture to at least 75 DEG C., and separating the particulate solid product. The barium metaborate particles may be produced in the presence of the silicate, e.g. by reacting barium sulphide or hydroxide with borax or boric acid, the silicate being added with one or other of the reactants, or the reactants being added to a silicate solution; or the silicate may be added to a preformed suspension of barium metaborate particles. The products, on extraction with water at 25 DEG C. yield extracts which contain not more than 0.3% by weight of solids, and are useful as preservative pigments in oil paints and water emulsion paints. Specification 813,228 and U.S.A. Specification 2,818,344 are referred to.