| 摘要 |
<p>PURPOSE:To obtain a soft highly foamed molded article having a uniform fine cellular structure continuously at a low cost, by gelatinizing a compositin consisting of a vinyl chloride resin essntially in an extruder under heating, and injecting a specific blowing agent into the gelatinized material. CONSTITUTION:(A) A vinyl chloride resin is incorporated with (B) a nucleating agent, e.g. calcium carbonate having a melting point above that of the resin, (C) a plasticizer, e.g. dioctyl phthalate, (D) an acrylic resin and (E) a decompositin type blowing agent, e.g. azodicarbonamide, at a weight ratio of the components (A)/(B)/(C)/(D)/(E) of 100/0.01-40/5-100/0.5-30 (preferably 3-20)/0.1-20. The resultant composition is then fed to an extruder and gelatinized under heating. An organic solvent blowig agent, e.g. propane, having a boiling point <=90 deg.C, preferably <=70 deg.C, in an amount of 1-20wt% based on the component (A) is injected into the gelatinized material to foam and mold the material.</p> |
