| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing an extrusion-foamed polystyrenic resin board using a foaming agent comprising saturated hydrocarbons composed mainly of isobutane, methyl formate and carbon dioxide, and forming a foamed board having sufficiently small apparent density of≤50 kg/m<SP POS="POST">3</SP>, excellent mechanical strength and excellent flame retardancy, etc. <P>SOLUTION: The method for producing the extrusion-foamed polystyrenic resin board is characterized in that: the foamed resin board has apparent density of 20-50 kg/m<SP POS="POST">3</SP>and the thickness of≥10 mm, wherein the physical foaming agent is composed of 30-70 mol% of specific saturated hydrocarbons, 10-50 mol% of methyl formate and 5-40 mol% of carbon dioxide, the compounding amount of the physical foaming agent is 1.1-1.8 mol based on 1 kg of the polystyrenic resin; and the polystyrenic resin is a mixture of 10-60 wt.% of a polystyrenic resin (PSL) having a weight-average molecular weight of≥100,000 and <300,000 and 90-40 wt.% of a polystyrenic resin (PSH) having a weight-average molecular weight of≥300,000. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
