A photocurable composition containing metal oxide nanoparticles (X), a photopolymerizable compound (B), and a photoradical polymerization initiator (C), in which the content of the photoradical polymerization initiator (C) is 10 parts by mass or more with respect to 100 parts by mass of the total content of the metal oxide nanoparticles (X) and the photopolymerizable compound (B).

A photocurable composition containing metal oxide nanoparticles (X), a photopolymerizable compound (B), and a photoradical polymerization initiator (C), in which the content of the photoradical polymerization initiator (C) is 10 parts by mass or more with respect to 100 parts by mass of the total content of the metal oxide nanoparticles (X) and the photopolymerizable compound (B).

An optical material organic compound having characteristics that the dispersion characteristic (Abbe number (.sub.d)) and the secondary dispersion characteristic (g,F) of the refractive index are high, the transmittance in the visible light region is high, and the chromatic aberration correction function delivers high performance, which represented by the general formula (1) or (2) is provided.

An optical material organic compound having characteristics that the dispersion characteristic (Abbe number (.sub.d)) and the secondary dispersion characteristic (g,F) of the refractive index are high, the transmittance in the visible light region is high, and the chromatic aberration correction function delivers high performance, which represented by the general formula (1) or (2) is provided.

The present invention provides: a photocurable composition that, although including metal oxide microparticles at high concentration, is such that the metal oxide microparticles are satisfactorily dispersed and leakability to a to-be-coated substrate is satisfactory; a cured product of said photocurable composition; and a cured film formation method that uses the photocurable composition. A photocurable resin composition contains a photopolymerizable compound (A), metal oxide microparticles (B), an initiator (C), and a solvent (S). A compound having a radical-polymerizable-group-containing group or a cationically-polymerizable-group-containing group is used as the photopolymerizable compound (A). As the solvent (S), a plurality of solvents (S1) are used that have a specific structure that includes an oxyalkylene group, and are such that the Hildebrand solubility parameter value thereof is 21.0 MPa.sup.0.5 (alternatively, the solvent (S1) and another solvent (S2) are used at a prescribed mass ratio).

A phase difference plate includes a phase difference plate P1 and a phase difference plate P2. An in-plane slow axis of the phase difference plate P1 is orthogonal to an in-plane slow axis of the phase difference plate P2. The phase difference plate P2 includes a layer of a liquid crystal material oriented in an in-plane direction. An in-plane retardation ReP2(?) at a wavelength A nm of the phase difference plate P2 satisfies the following formulae (e1) and (e2): {Re2 (400)?Re2(550)}/{Re2(550)?Re2(700)}<2.90 (e1), and Re2(400)/Re2(700)>1.13 (e2). An in-plane retardation ReP1(?) of the phase difference plate P1 at a wavelength ? nm and the in-plane retardation ReP2(?) of the phase difference plate P2 at the wavelength ? nm satisfy the following formulae (e4) and (e5): ReP1(550)>ReP2(550) (e4), and ReP1(400)/ReP1(700)<ReP2(400)/ReP2(700) (e5).

A phase difference plate includes a phase difference plate P1 and a phase difference plate P2. An in-plane slow axis of the phase difference plate P1 is orthogonal to an in-plane slow axis of the phase difference plate P2. The phase difference plate P2 includes a layer of a liquid crystal material oriented in an in-plane direction. An in-plane retardation ReP2(?) at a wavelength A nm of the phase difference plate P2 satisfies the following formulae (e1) and (e2): {Re2 (400)?Re2(550)}/{Re2(550)?Re2(700)}<2.90 (e1), and Re2(400)/Re2(700)>1.13 (e2). An in-plane retardation ReP1(?) of the phase difference plate P1 at a wavelength ? nm and the in-plane retardation ReP2(?) of the phase difference plate P2 at the wavelength ? nm satisfy the following formulae (e4) and (e5): ReP1(550)>ReP2(550) (e4), and ReP1(400)/ReP1(700)<ReP2(400)/ReP2(700) (e5).

A polymerizable compound has a practical low melting point, excellent solubility in a general-purpose solvent, and can produce an optical film at low cost, exhibits low reflected luminance, and achieves uniform conversion of polarized light over a wide wavelength band, an optically anisotropic article.

A polymerizable compound has a practical low melting point, excellent solubility in a general-purpose solvent, and can produce an optical film at low cost, exhibits low reflected luminance, and achieves uniform conversion of polarized light over a wide wavelength band, an optically anisotropic article.

A polymerizable compound has a practical low melting point, excellent solubility in a general-purpose solvent, and can produce an optical film at low cost, exhibits low reflected luminance, and achieves uniform conversion of polarized light over a wide wavelength band, an optically anisotropic article. A carbonyl compound is useful as a raw material for producing the polymerizable compound. (In the formula (I), Y.sup.1 to Y.sup.8 represent C(O)O, G.sup.1 and G.sup.2 represent a C.sub.1-20 divalent linear aliphatic group, Z.sup.1 and Z.sup.2 represent a C.sub.2-10 alkenyl group that is unsubstituted, or substituted with a halogen atom, A.sup.x represents a C.sub.2-30 organic group with at least one aromatic ring, A.sup.y represents a hydrogen atom or C.sub.1-20 alkyl group, A.sup.1 represents a trivalent aromatic group, A.sup.2 and A.sup.3 represent a C.sub.3-30 divalent alicyclic hydrocarbon group, A.sup.4 and A.sup.5 represent a C.sub.6-30 divalent aromatic group or the like, and Q.sup.1 represents a hydrogen atom.) ##STR00001##