PURPOSE: To disperse a large amount of pigment homogeneously in a resin, and to prepare a high concentration master batch having excellent pigment dispersibility, by mixing a polyolefin elastic resin with a pigment at a low temperature lower than a specific temperature.
CONSTITUTION: The objective master batch is prepared by mixing (A) a polyolefin elastic resin (pref. an ethylene-α-olefin copolymer having an MI value of 0.5W50 and a Vicat softening point of 50W100°C) with (B) a pigment at ≤120°C, e.g. by a Banbury mixer. The ratio of the resin to the pigment is pref. 1:0.7W4 in case of inorganic pigments, and 1:1W2 in case of organic pigments.
EFFECT: Homogeneous dispersion of the pigment in the molded article. Free from mottling, grit, etc. High color density by a small amount of pigment.
ANDOU TSUNENOBU
NAKAYASU MASAHIRO
HIRAMA TATSUO
NOGUCHI KAZUTOKI
