Dispersant composition for carbon nanotube

A dispersant composition for carbon nanotubes comprising:

• a copolymer that includes a structural unit A represented by the following general formula (1) and a structural unit B represented by the following general formula (2);
• and
• a solvent,
• wherein the content of the structural unit B in all structural units of the copolymer is 20 mass % or more:
• where R1, R2, R3, R5, R6, and R7 are the same or different from each other and are each a hydrogen atom, a methyl group, or an ethyl group, R4 is a hydrocarbon group having 16 to 30 carbon atoms, R8 is a linear or branched alkylene group having 2 to 3 carbon atoms, X1 is an oxygen atom or NH, X2 is an oxygen atom, p is the number of 1 to 8, and R9 is a hydrogen atom, a methyl group, or an ethyl group,
• wherein, in the structural unit B represented by the general formula (2), a structural unit b1 in which X2 is an oxygen atom, p is 1, and R9 is a hydrogen atom accounts for 50 mass % or more of the total amount of the structural unit B, and
• wherein the copolymer includes the structural unit B that includes both the structural unit b1 and at least one structural unit selected from a structural unit b2 in which X2 is an oxygen atom, p is 1, and R9 is a methyl group and a structural unit b3 in which X2 is an oxygen atom, p is 2, and R9 is a methyl group, or the copolymer further includes at least one structural unit C selected from structural units represented by the following general formula (3), structural units derived from acrylic acid monomers, structural units derived from (meth)acrylic acid esters having 1 to 15 carbon atoms, and structural units derived from (meth)acrylamides:
• where R10, R11, R12, and R14 are the same or different from each other and are each a hydrogen atom, a methyl group, or an ethyl group, R13 is a linear or branched alkylene group having 2 to 4 carbon atoms, X3 is an oxygen atom, and q is the number of 9 to 10.