PURPOSE: To prepare the title resin having excellent impact strength, tensile strength, and elongation at break, and useful as food containers, by the radical polymerization of a solution obtained by dissolving a specific butadiene-isoprene copolymer in a vinyl monomer.
CONSTITUTION: A butadiene-isoprene copolymer is dissolved in a vinyl monomer containing ≥50 wt.% of styrene, and the solution is subjected to the radical polymerization by bulk-polymerization or bulk-suspension polymerization. The content of isoprene in the copolymer is 3W40 wt.%, pref. 3W30 wt.%; the ratio of 1, 2- vinyl bond in the butadiene segment is 10W40 %, pref. 11W20 %; and the ratio of the weight average molecular weight to the number average molecular weight of the copolymer is ≥1.5, pref. 1.8W4.0. When the isoprene content of the copolymer exceeds 40 wt.%, the resulting resin has only poor impact strength and elongation at break.
IEMORI AKIO
IHARAKI TOSHIO
HONDA MAKOTO
