| 摘要 |
PURPOSE: To obtain expandable beads having excellent moldability and giving a block molding which is reduced in stringing during fusion cutting and hence gives a satisfactory cut surface by imparting specific properties to expandable PS resin beads. CONSTITUTION: The resin beads give a molding which, when analyzed with a capillary rheometer of the temp.-rising type using a die with dimensions of 1mm (ϕ) by 10mm (L) at a cylinder pressure of 20kgf/cm<2> and a heating rate of 6 deg.C/min, has melt viscosities of 50,000 P or higher, preferably 80,000-180,000 P, at 170 deg.C and of 10,000 P or lower, preferably 1,000-9,000 P, at 195 deg.C. The resin beads contain 0.01-3.0wt.% free-radical generator having a 1-min half-life temp. of 165-320 deg.C (e.g. dicumyl peroxide).
|
