摘要 |
PURPOSE:To make a filler usable without applying classification treatment, by using a fine particle composed of a crosslinked polymer obtained by modifying a fine particle composed of a low crosslinked polymer obtained by a seed polymerization system with crosslinkable monomer and a non-crosslinkable monomer. CONSTITUTION:This filler is composed of a fine particle of a crosslinked polymer obtained by absorbing a crosslinkable monomer and a non-crosslinkable monomer by fine particle of a low crosslinked polymer and copolymerizing both monomers. Since it is generally required that the non-crosslinkable monomer and the crosslinkable monomer are excellent in pressure resistance, a styrenic monomer formed into a polymer having a high glass transition point is pref. used as the non-crosslinkable monomer and divinylbenzene low in water solubility is pref. used as the crosslinkable monomer. The crosslinking degree of the low crosslinked polymer is pref. set so that a swelling degree due to monomer to be used is 4-150, pref., 8-100 and the particle size thereof is 0.5-15mum and the standard deviation of the particle size distribution thereof is more pref, 0.05mum or less. By this method, the filler can be used without applying classification treatment. |