COMPOSITE RESIN PRE-EXPANDED PARTICLES CONTAINING CARBON BLACK AND METHOD FOR PRODUCING SAME, AND EXPANDED MOLDED ARTICLE

摘要

Composite resin pre-expanded particles containing carbon black, which comprises 100 parts by mass of a polyolefin resin containing carbon black and 100 to 400 parts by mass of a polystyrene resin. The composite resin pre-expanded particles containing carbon black have a carbon black content of 0.5 to 5.0% by mass and a bulk density of 0.015 to 0.25 g/cm3. Each of the composite resin pre-expanded particles containing carbon black has an outermost surface layer having a thickness of 30 to 80μm when the composite resin pre-expanded particles are subjected to a test comprising: (a) slicing each of the composite resin pre-expanded particles containing carbon black in a thickness of 1 mm so that a bubble-containing cross section can appear on both sides of the sliced particle, thereby producing a sliced product: (b) immersing the sliced product in toluene at 25ºC for 24 hours to extract the polystyrene resin component from the sliced product; (c) subsequently taking a picture of an enlarged view of the cross section of the sliced product on a microscope; and (d) observing the produced microscopic image.