40%. [0066] As the block copolymer in the present invention, it is preferred that the block copolymer has a bonding type selected from a-b, a-b-a and a-b-a-b types, wherein (a) is the polymer block mainly composed of the aromatic vinyl compound and (b) is the polymer block mainly composed of the conjugated diene compound. [0067] Among these, more preferred is a-b-a type.