| 摘要 |
<p>PROBLEM TO BE SOLVED: To carry out the compositing or surface modicication of solid particles and enable the content of fine particles to be freely adjusted by fixing fine particles (child particles) to the surfaces of core particles (mother particles) and causing the crystals of the fixed fine particles to grow. SOLUTION: Cellulose or its deriv., starch or its deriv., a synthetic polymer (e.g. nylon), a metal powder (e.g. a nickel or iron powder), or an inorg. powder (e.g. an alumina powder) is used as the mother particles; and an inorg. or org. compd. having crystallizing properties, as child particles. The child particles are fixed to the surfaces of the mother particles by a mechanical method, such as an impact method in a high-speed air flow. When calcium monohydrogenphosphate (CaHPO4 ), having a very low water solubility, is used as the child particles, the crystal growth of fixed child particles is conducted by a solid-liquid reaction method in the supersatd. state. For instance, a calcium hydroxide suspension is reacted with pyrophosphoric acid in an aq. soln. adjusted to a pH of 4.5-5.8, pref. 5.7, thus forming CaHPO4 and causing the crystals of CaHPO4 to grow while using CaHPO4 fixed on the mother particles as crystallization nuclei.</p> |
