Provided is a composition including: an acrylamide compound represented by general formula (1) in 20% by mass or greater but 50% by mass or less; a multifunctional monomer in 40% by mass or greater but 70% by mass or less; and a polymerization initiator,
where in general formula (1), R
1
represents alkyl group containing 1 through 6 carbon atoms, X represents alkylene group containing 1 through 6 carbon atoms, and Y represents any one selected from the group consisting of general formula (2) below and general formula (3) below,
where in general formula (2), R
2
represents alkyl group containing 1 through 10 carbon atoms, and * represents binding site with X above,
where in general formula (3), R
2
represents alkyl group containing 1 through 10 carbon atoms, and * represents binding site with X above.
提供的是一种组合物,包括:质量分数为20%或更高但不超过50%的一种由一般式(1)表示的
丙烯酰胺化合物;质量分数为40%或更高但不超过70%的多功能单体;以及聚合
引发剂。其中,在一般式(1)中,R1表示含有1至6个碳原子的烷基基团,X表示含有1至6个碳原子的亚烷基基团,Y表示从以下公式(2)和以下公式(3)组成的群中任选一种。在一般式(2)中,R2表示含有1至10个碳原子的烷基基团,“*”表示与上述X结合的结合位点。在一般式(3)中,R2表示含有1至10个碳原子的烷基基团,“*”表示与上述X结合的结合位点。