Patent ID: 7767723

Claim:
A method for producing expandable particles of a styrene-modified linear low-density polyethylene-based resin comprising, in the order recited: dispersing 100 parts by weight of non-crosslinked linear low-density polyethylene-based resin particles, 50 to 1000 parts by weight of a styrene-based monomer, and 0.1 to 0.9 parts by weight of a polymerization initiator relative to 100 parts by weight of the styrene-based monomer into a suspension containing a dispersant; impregnating the styrene-based monomer into the low-density polyethylene-based resin particles by heating a resultant dispersion at such a temperature that polymerization of the styrene-based monomer does not substantially take place; performing a polymerization of the styrene-based monomer at a temperature of (T−15) to (T−8)° C. or (T+1) to (T+5)° C., T° C. being a melting point of the low-density polyethylene-based resin particles; and impregnating a volatile blowing agent into the resin particles during or after the polymerization; whereby resin components of the expandable particles contain a gel component comprising less than 2 wt % of a graft polymer.