| abstract |
Provided is a block polymer capable of providing an adhesive that is excellent in initial adhesiveness, low increase in adhesiveness, expandability, and oil resistance, and that hardly leaves an adhesive residue on an adherend.Provided is a block polymer including two or more polymer block As each having a value β of 0.20 or less and a functional group F containing at least one element selected from a group consisting of nitrogen, silicon, oxygen, and sulfur in a part or all of terminals of the two or more polymer block As, in which the block polymer has a value α of 0.75 or more, when p, q, r and s are defined as a component proportion (molar proportion) of a structural unit represented by Formula (1), a component proportion of a structural unit represented by Formula (2), a component proportion of a structural unit represented by Formula (3), and a component proportion of a structural unit represented by Formula (4), in the polymer, respectively. α=p+0.5×r/p+q+0.5×r+sβ=p+q/p+q+0.5×r+s |