BLOCK COPOLYMER AND ADHESIVE
Provided is a block copolymer containing 10 mass % or more of a polymer (A1) having a multi-branched structure having four or more polymer chains, the polymer chain having a polymer block A containing 70 mass % or more of a structural unit derived from a conjugated diene compound and a polymer block B containing 70 mass % or more of a structural unit derived from an aromatic vinyl compound, the block copolymer having a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen, and sulfur in a part or all of terminals of the four or more polymer chains, and the block copolymer having a value α of 0.75 or more represented by the following equation (i), when p, q, r, and s are defined as component proportions (molar proportions) of structural unit represented by the following formula (1) to formula (4), in the polymer, respectively.
1 . A block copolymer comprising:
10 mass % or more of a polymer (A1) having a multi-branched structure having four or more polymer chains,
wherein the polymer chain includes a polymer block A containing 70 mass % or more of a structural unit derived from a conjugated diene compound, and a polymer block B containing 70 mass % or more of a structural unit derived from an aromatic vinyl compound,
wherein a functional group F containing at least one element selected from the group consisting of nitrogen, silicon, oxygen, and sulfur is contained at a part or all of the terminals of the four or more polymer chains, and
wherein the block polymer has a value α of 0.75 or more represented by the following equation (i), where p is defined as a component proportion (molar proportion) of a structural unit represented by the following formula (1), q is defined as a component proportion (molar proportion) of a structural unit represented by the following formula (2), r is defined as a component proportion (molar proportion) of a structural unit represented by the following formula (3), and s is defined as a component proportion (molar proportion) of a structural unit represented by the following formula (4), in the polymer.
2 . The block copolymer according to claim 1 comprising 20 to 90 mass % of the polymer (A1).
3 . The block copolymer according to claim 1 comprising 50 to 80 mass % of the polymer (A1).
4 . The block copolymer according to claim 1 ,
wherein the functional group F has at least one selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group.
5 . The block copolymer according to claim 1 ,
wherein the polymer block A has the functional group F at a terminal of the polymer block A, or the polymer block B has the functional group F at a terminal of the polymer block B.
6 . The block copolymer according to claim 1 ,
wherein the polymer (A1) has a structure in which four or more polymer chains are allowed to bond to a partial structure derived from a coupling agent, and
the coupling agent has a functional group containing nitrogen.
7 . The block polymer according to claim 1 ,
wherein a value β represented by the following equation (ii) in the polymer block A is more than 0.20.
β=( p+q )/( p+q +(0.5× r )+ s ) (ii)
8 . The block copolymer according to claim 7 ,
wherein the value β is more than 0.60.
9 . The block copolymer according to claim 1 ,
wherein the polymer (A1) further comprises a polymer block C having a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound.
10 . The block copolymer according to claim 1 , comprising a linear polymer (A2).
11 . An adhesive, which is obtained by using the block copolymer according to claim 1 .
12 . The block copolymer according to claim 2 ,
wherein the functional group F has at least one selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group.
13 . The block copolymer according to claim 3 ,
wherein the functional group F has at least one selected from the group consisting of a primary amino group, a secondary amino group, and a tertiary amino group.
14 . The block copolymer according to claim 2 ,
wherein the polymer block A has the functional group F at a terminal of the polymer block A, or the polymer block B has the functional group F at a terminal of the polymer block B.
15 . The block copolymer according to claim 3 ,
wherein the polymer block A has the functional group F at a terminal of the polymer block A, or the polymer block B has the functional group F at a terminal of the polymer block B.
16 . The block copolymer according to claim 4 ,
wherein the polymer block A has the functional group F at a terminal of the polymer block A, or the polymer block B has the functional group F at a terminal of the polymer block B.
17 . The block copolymer according to claim 12 ,
wherein the polymer block A has the functional group F at a terminal of the polymer block A, or the polymer block B has the functional group F at a terminal of the polymer block B.
18 . The block copolymer according to claim 13 ,
wherein the polymer block A has the functional group F at a terminal of the polymer block A, or the polymer block B has the functional group F at a terminal of the polymer block B.
19 . The block copolymer according to claim 2 ,
wherein the polymer (A1) has a structure in which four or more polymer chains are allowed to bond to a partial structure derived from a coupling agent, and
the coupling agent has a functional group containing nitrogen.
20 . The block copolymer according to claim 3 ,
wherein the polymer (A1) has a structure in which four or more polymer chains are allowed to bond to a partial structure derived from a coupling agent, and
the coupling agent has a functional group containing nitrogen.