摘要 |
More perfect, less porous hollow microspheres can be prepared by spray-drying dispersions of film-forming solids that contain certain organic solvents. The organic solvents are water-miscible and have boiling points of 100 DEG C. or more. The solvent is added just prior to spray drying and the resulting product has fewer cracks and/or holes. This improvement is especially beneficial to preparation systems involving alkali metal silicates and "polysalts.
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