| 摘要 |
PURPOSE:To prevent burning due to shearing heat, and improve the mechanical prop erty and processability of an impact resistant strength or the like by blending a high temperature softening component and a low temperature softening component prior to melting the low temperature softening component in a fire-retardant resin composi tion. CONSTITUTION:Before the low temperature softening component in a fire-retardant resin composition melts, a high temperature softening component is blended to a low temperature softening component, and then they are pelletized by means of a nonengagement type the same directionally rotating biaxial extruder, and an engage ment type or nonengagement type different directioanlly rotating biaxial extruder. As the fire-retardant resin composition, a resin composition is most suitable that is liable to be thermally decomposed by shearing heat. In particular, a composition consisting of styrene resin and vinyl chloride resin is most suitable therefor. For exam ple, it consists of 30-80wt.% of stylene resin wherein the reduced viscosity of a methyl- ethyl ketone soluble part is 0.20-0.55l/g (N,N-dimethylformamide solution, temperature of 30 deg.C, density of 0.3g/dl), and 70-20wt.% vinyl chloride resin of 400-800 in its average polymerization degree. And, the glass transition temperature of methyl-ethyl ketone soluble part of the stylene resin is preferable to be 110 deg.C or higher. |
