PROCESS FOR MAKING DRY MICROSPHERES AND MICROSPHERE PRODUCT

摘要

Microsphere (10) wet cake, is mixed with a surface barrier coating (14) effective to prevent agglomeration and surface bonding of the microspheres. Water is removed by drying at high shear with continuous mixing. In a subsequent step, by controlling the application of heat to balance temperature and coupling this with low shear mixing, blowing agent (12) will produce controlled expansion of the microspheres. The surface barrier coating (14) in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials (14) include by way of example, dry inorganic pigments or filler materials, and the like, and related inorganic materials.