Pre-expanded articles of a polyolefin resin having microcell and process for preparing thereof

摘要

The present invention relates to a process for preparing pre-expanded articles of a polyolefin resin wherein a blowing agent is incorporated into the polyolefin resin in an amount of 45 to 90 parts by volume with respect to 100 parts by volume of the resin and the pre-expansion is carried out at a temperature in the range of from Tm -35 DEG C. to Tm -20 DEG C., or a second external pressured gas which facilitate the impregnation efficiency of the blowing agent is further introduced in an amount of expressing an additional pressure more than 10 kg/cm2 with the blowing agent. Also, the present invention relates to pre-expanded articles of a polyolefin resin produced by the above process.