Tetra-block copolymer, and polymer composition, and hot-melt sticky adhesive composition using these

Abstract

A tetrablock copolymer having an aromatic vinyl block (A1), a conjugated diene block (B1), an aromatic vinyl block (A2), and a conjugated diene block (B2) is provided, wherein Mw(A2)/Mw(A1) is 1.2 to 5, Mw(A2) is 12,000 or more, Mw(B1)>Mw(B2), Mw(Total) is 50,000 to 400,000 where the weight average molecular weight of the aromatic vinyl block (A1) is defined as Mw(A1), the weight average molecular weight of the conjugated diene block (B1) is defined as Mw(B1), the weight average molecular weight of the aromatic vinyl block (A2) is defined as Mw(A2), the weight average molecular weight of the conjugated diene block (B2) is defined as Mw(B2), and the weight average molecular weight of the tetrablock copolymer as a whole is defined as Mw(Total), and the content of aromatic vinyl monomer units is 10 to 30% by weight.

Dependencies are inferred from the claim text.