PURPOSE: To improve monodispersivity by firing a polymer particulate synthesized by the seed polymerization and by making standard deviation of particle diameter distribution lower than a specific ratio to av. particle diameter.
CONSTITUTION: A seed polymer particulate such as a styrenic polymer is uniformly dispersed into water. A specific amount of an oil-soluble ethylenically unsaturated monomer such as styrene, a polyfunctional monomer such as divinylbenzene, 0.1-10 pts. of an oil-soluble polymerization initiator such as benzoyl peroxide per 100wt.% total monomer and a surfactant are added in water and are mixed and are ultrasonic-treated. A part of the emulsified solution is added into a dispersing solution of the seed polymer particulate to absorb the monomer into the seed polymer. Total monomer is absorbed into the seed polymer by repeating this process and is polymerized. The polymer particulate obtained is washed, dried and is fired in a stream of N2 at 300 to 2000°C to obtain the uniform particle diameter fired particulate having ≤20% standard deviation of particle diameter distribution to 1-100μm av. particle diameter.
YOSHIMATSU AKIRA