Optically anisotropic layer, optical film, polarizing plate, and image display device

An optically anisotropic layer obtained by curing a polymerizable liquid crystal composition including a rod-like liquid crystal compound and a monofunctional compound, and immobilizing an alignment state of the rod-like liquid crystal compound,

• wherein the rod-like liquid crystal compound has polymerizable groups P1 and P2 constituting one terminal and the other terminal of the rod-like liquid crystal compound, respectively, and three or more rings B1 selected from the group consisting of an aromatic ring which may have a substituent and an alicyclic ring which may have a substituent, and existing on a bond that links the polymerizable groups P1 and P2,
• the monofunctional compound has a polymerizable group P3 polymerizable with the rod-like liquid crystal compound, a cyclic organic group B2 which may have a substituent, and one or more rings B3 selected from the group consisting of an aromatic ring which may have a substituent and an alicyclic ring which may have a substituent, and existing on a bond that links the polymerizable group P3 and the cyclic organic group B2,
• in the monofunctional compound, the polymerizable group P3 constitutes one terminal of the monofunctional compound, and the cyclic organic group B2 constitutes the other terminal of the monofunctional compound,
• the number a1 of atoms of the rod-like liquid crystal compound and the number a2 of atoms of the monofunctional compound satisfy a relationship of Expression (1),
• the rod-like liquid crystal compound is immobilized in a state of being vertically aligned with respect to a main surface of the optically anisotropic layer,
• 0.2<a2/a1≤0.68 Expression (1)
• the number a1 of atoms of the rod-like liquid crystal compound represents the number of atoms on a bond that links one terminal and the other terminal of the rod-like liquid crystal compound at a shortest distance, and is construed not to include hydrogen atoms, and the number a2 of atoms of the monofunctional compound represents the number of atoms on a bond that links one terminal and the other terminal of the monofunctional compound at a shortest distance, and is construed not to include hydrogen atoms,
• where one terminal and the other terminal of a compound mean a starting atom and an ending atom, respectively, for which a maximum number of atoms is calculated in a case where the atoms on a bond of the compound are linked at the shortest distance.