反应详情

In a pressure resistant reactor, 23.3 kg of cyclohexane, 5.56 millimoles of TMEDA, and 1.55 kg of styrene were added, and while the mixture was stirred at 40° C., 185.0 millimoles of n-butyllithium was added thereto. While the temperature was elevated to 50° C., polymerization was carried out for one hour. The polymerization conversion ratio for styrene was 100%. Subsequently, while the temperature was controlled to be maintained at 50° C. to 60° C., 5.20 kg of isoprene was continuously added to the reactor over one hour. After completion of the addition of isoprene, polymerization was carried out for another one hour. The polymerization conversion ratio for isoprene was 100%. Thereafter, 35.2 millimoles of tetrachlorosilane was added to the reactor as a coupling agent, and a coupling reaction was carried out for 2 hours. Thus, a branched styrene-isoprene block copolymer was formed, which would serve as a block copolymer B. Subsequently, 9.25 millimoles of methanol was added to the reactor, and thereby the active terminal of a portion of the styrene-isoprene block copolymer was deactivated. Thereafter, while the temperature was controlled to be maintained at 50° C. to 60° C., 3.25 kg of styrene was continuously added to the reactor over one hour. After completion of the addition of styrene, polymerization was carried out for another one hour, and thus a styrene-isoprene-styrene block copolymer was formed, which would serve as a block copolymer A. The polymerization conversion ratio for styrene was 100%. Subsequently, 370.0 millimoles of methanol was added to the system as a polymerization terminator, the resulting mixture was thoroughly mixed, and the reaction was terminated. A portion of the reaction liquid thus obtained was taken out, and the same measurements as in Example 1 were made. These values are presented in Table 2. The subsequent operation was carried out in the same manner as in Example 1, and a block copolymer composition of Example 2 was collected. The block copolymer composition was fabricated into pellets and was thereby formed into a film of Example 2. Measurements were made for this film. The results are presented in Table 2.

1. temperatureto be maintained at 50° C. to 60° C.