Phase difference film

A phase difference film comprising:

• a copolymer containing at least one selected from a nit represented by Formula (1) and a unit represented by Formula (2), and a unit represented by Formula (3),
• wherein 20 nm<Re (548)<300 nm,
• 0.5<Re (446)/Re (548)<1.0, and
• 1.0<Re (629)/Re (548)<2.0;
• where, Re (446), Re (548), and Re (629) represent in-plane retardation at respective wavelengths of 446 nm, 548 nm, and 629 nm;
• in Formula (1), R11 to R14 each independently represent a hydrogen atom or a substituent having a Hammett substituent constant σp value of less than −0.15, except for an aryl group, a heteroaryl group, and a substituent having a reactive group, and in R11 to R14, substituents adjacent to each other are not bonded to each other to form a fused ring;
• R15 to R17 each independently represent a substituent;
• a to c each independently represent an integer of 0 or more and represent an integer of equal to or less than the maximum number of substitution on each ring;
• in a case where a to c each are an integer of 2 or more, a plurality of R15's, a plurality of R16's, and a plurality of R17's may be identical to or different from each other;
• Ar11 and Ar12 each independently represent an aryl group including a benzene ring surrounded by a broken line or a heteroaryl group including a benzene ring surrounded by a broken line;
• L11 and L12 each independently represent an alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 12 carbon atoms, an arylene group having 6 to 20 carbon atoms;
• or a heteroarylene group having 6 to 20 carbon atoms;
• n11 and n12 each independently represent an integer of 0 to 10;
• in a case where n11 and n12 are an integer of 2 to 10, a plurality of L11's and a plurality of L12's may be identical to or different:
• from each other;
• in a case where Ar11 and Ar12 each independently represent an aromatic fused ring group including a benzene ring surrounded by a broken line, R15, R16, —O—[L11-O]n11-, and [O-L12]n12—O— each independently may be substituted at the benzene ring surrounded by a broken line and may be substituted at a ring included in a fused ring other than the benzene ring surrounded by a broken line;
• in Formula (2), Y21 and Y22 each independently represent a carbon atom, an oxygen atom, a sulfur atom, or a nitrogen atom, and at least one Y21 or Y22 is an oxygen atom, a sulfur atom, or a nitrogen atom;
• Z is an atomic group that forms a 5-membered to 7-membered ring with Y21—C═C—Y22, in which ring-constituting atoms of the atomic group includes a carbon atom, an oxygen atom, a sulfur atom, or a nitrogen atom;
• R21 to R24 each independently represent a substituent;
• p to s each independently represent an integer of 0 or more and represent an integer of equal to or less than the maximum number of substitution on each ring;
• in a case where p to s each are an integer of 2 or more, a plurality of R21's, a plurality of R22's, a plurality of R23's, and a plurality of R24's may be identical to or different from each other;
• Ar21 and Ar22 each independently represent an aryl group including a benzene ring surrounded by a broken line or a heteroaryl group including a benzene ring surrounded by a broken line;
• X21 and X22 each independently is a group selected from a single bond, —O—, and —S—;
• L21 and L22 each independently represent an alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 12 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a heteroarylene group having 6 to 20 carbon atoms;
• m21 and m22 each independently represent an integer of 0 to 0.10;
• in a case where m21 and m22 each are an integer of 2 to 10, a plurality of -[L21-X21]-'s and a plurality of —[X22-L22]-'s may be identical to or different from each other;
• in a case where Ar21 and Ar22 are each independently an aromatic fused ring group including a benzene ring surrounded by a broken line, R21, R22, —O-[L21-x21]m2—, and —[X22-L22]m22-O— may be each independently substituted at the benzene ring surrounded by a broken line or may be substituted at a ring included in a fused ring other than the benzene ring surrounded by a broken line;
• and
• in Formula (3), X32 represents an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group having 4 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a group obtained by a combination thereof;
• where, ring-constituting atoms of the cycloalkylene group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.