Production manner of styrene type resin grain for foaming, foaming Characteristic styrene type resin grain and its production manner

摘要

PROBLEM TO BE SOLVED: To obtain styrene resin particles for expansion having a narrow particle size distribution by suspension-polymerizing a styrene monomer in the presence of a difficultly water-soluble phosphate and a water-soluble sulfite or a water-soluble persulfate under specified conditions. ;SOLUTION: Water, a styrene monomer, 0.03-1wt.%, based on the styrene monomer, difficultly water-soluble phosphate, 1.5-100ppm of water-soluble sulfite or 0.1-50ppm of water-soluble persulfate and a radical polymerization initiator are introduced into a polymerizer and dissolved and dispersed under agitation to obtain a suspension. This suspension is subjected to a suspension polymerization reaction under such agitation that the peripheral speed of the impeller is 2.3-5.5m/sec. to obtain a styrene resin particles for expansion having a median particle diameter of 0.20-2.0mm. These particles are impregnated with 3-15wt.% blowing agent to obtain expandable styrene resin particles.;COPYRIGHT: (C)1997,JPO