| abstract |
A copolymer composition comprising 100 parts by mass of a copolymer comprising a structural unit derived from a monomer represented by a formula (1) and a structural unit derived from another radical polymerizable monomer, and having a content of a phosphorus atom derived from the monomer represented by the formula (1) of 0.5 to 6.0% by mass, and 0.01 to 7.0 parts by mass of a compound represented by a formula (2),wherein in the formula (1), Rrepresents a hydrogen atom or a methyl group, Rrepresents an alkylene group having 1 to 4 carbon atoms, and Rand Reach independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms,wherein in the formula (2), Rrepresents an alkylene group having 1 to 4 carbon atoms, Rand Reach independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and Rrepresents an alkyl group having 1 to 10 carbon atoms. |