反应详情

Into a reaction vessel with a stirrer, 50 kg of cyclohexane, 1,400 g of well dehydrated styrene and 105 g of sec-butyl lithium (10% by weight, cyclohexane solution) were charged to carry out polymerization at 60° C. for 60 minutes. Next, 7,200 g of a mixture of isoprene and butadiene (weight ratio: 50/50) was added to carry out polymerization for 60 minutes, and 1,400 g of styrene was further added to carry out polymerization for 60 minutes. Thereafter, methanol was added to terminate the reaction. Thus, a styrene-isoprene/butadiene-styrene type block copolymer was obtained. The block copolymer obtained was subjected to hydrogenation under the same conditions as in Reference Example 1 to give a hydrogenated product of the block copolymer (hereinafter simply referred to as "SEEPS"). The SEEPS thus obtained had a number average molecular weight of 103,400 and a styrene content of 28% by weight, where the ratio of hydrogenation was 97.3%.

1. custompolymerization at 60° C. for 60 minutes
2. custompolymerization for 60 minutes
3. custompolymerization for 60 minutes
4. customto terminate
5. customthe reaction