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-shaped liquid crystal compound having reverse wavelength dispersibility and a monofunctional compound, in an alignment state of the rod-shaped liquid crystal compound,

• wherein the rod-shaped liquid crystal compound is a compound represented by Formula (I),
• P1-Sp1-(X1-Ar1)n1-(X2-Cy1)m1-(X3-Ar3)m0-X4-(Cy2-X5)m2-(Ar2-X6)n2-Sp2-P2 (I)
• in Formula (I),
• P1 and P2 each independently represent an acryloyloxy group or a methacryloyloxy group,
• wherein P1 includes a first terminal atom and P2 includes a second terminal atom of the rod-shaped liquid crystal compound represented by Formula (I), wherein the first terminal atom of the rod-shaped liquid crystal compound is a starting atom and the second terminal atom of the rod-shaped liquid crystal compound represented by Formula (I) is an ending atom utilized to calculate a maximum number of atoms linked together at a shortest distance to form the rod-shaped liquid crystal compound represented by Formula (I), wherein the maximum number of atoms linked together at a shortest distance to form the rod-shaped liquid crystal compound represented by Formula (I) is counted such that the starting atom and the ending atom are also counted;
• Sp1 and Sp2 each independently represent a single bond, a linear alkylene group having 1 to 14 carbon atoms, a branched alkylene group having 3 to 14 carbon atoms, or a divalent linking group in which one or more of —CH2-'s constituting the linear alkylene group or the branched alkylene group are substituted with —O—, —S—, —NH—, —N(Q)-, or —CO—, where Q represents a substituent,
• n1, m1, m2, and n2 represent an integer from 0 to 2, provided that at least one of m1 or n1 represents 1 or more, and at least one of m2 or n2 represents 1 or more,
• m0 represents 1 or 2,
• X1, X2, X3, X4, X5, and X6 each independently represent a single bond;
• or —CO—, —O—, —S—, —C(═S)—, —CR1R2—, —CR3-CR4—, —NR5—, or a divalent linking group consisting of a combination of two or more of these groups, where R1 to R5 each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms, provided that in a case where n1 is 2, a plurality of X1's may be the same as or different from each other;
• in a case where m1 is 2, a plurality of X2's may be the same as or different from each other;
• in a case where m2 is 2, a plurality of X5's may be the same as or different from each other;
• and in a case where n2 is 2, a plurality of X6's may be the same as or different from each other,
• Ar1 and Ar2 each independently represent an aromatic ring which may have a substituent, provided that in a case where n1 is 2, a plurality of Ar1's may be the same as or different from each other;
• and in a case where n2 is 2, a plurality of Ar2's may be the same as or different from each other,
• Cy1 and Cy2 each independently represent an alicyclic ring which may have a substituent, provided that in a case where m1 is 2, a plurality of Cy1's may be the same as or different from each other;
• and in a case where m2 is 2, a plurality of Cy2's may be the same as or different from each other, and
• Ar3 represents any of aromatic rings selected from the group consisting of groups represented by Formulae (Ar-1) to (Ar-7),
• in Formulae (Ar-1) to (Ar-7), in a case where m0 represents 1, one of two * represents a bonding position to X3, and the other represents a bonding position to X4;
• in a case where m0 represents 2 and Ar3 exists between two X3s, two * represent a bonding position to X3, respectively;
• in a case where m0 represents 2 and Ar3 exists between X3 and X4, one of two * represents a bonding position to X3, and the other represents a bonding position to X4,
• Q1 represents N or CH,
• Q2 represents-S—, —O—, or —N(R6)—, where R6 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
• Y1 represents an aromatic hydrocarbon ring having 6 to 12 carbon atoms, which may have a substituent, an aromatic heterocyclic group having 3 to 12 carbon atoms, which may have a substituent, or an alicyclic hydrocarbon group having 6 to 20 carbon atoms, which may have a substituent, and one or more of —CH2-'s constituting the alicyclic hydrocarbon group may be substituted with —O—, —S—, or —NH—,
• Z1, Z2, and Z3 each independently represent a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a monovalent aromatic heterocyclic group having 3 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, —OR7, —NR8R9, —SR10, —COOR11, or —COR12, R7 to R12 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z1 and Z2 may be bonded to each other to form an aromatic ring,
• A3 and A4 each independently represent a group selected from the group consisting of —O—, —N(R13)—, —S—, and —CO—, where R13 represents a hydrogen atom or a substituent,
• X represents a non-metal atom of Groups XIV to XVI, to which a hydrogen atom or a substituent may be bonded,
• X11 and X12 each independently represent a single bond;
• or —CO—, —O—, —S—, —C(═S)—, —CR1R2—, —CR3-CR4—, —NR5—, or a divalent linking group consisting of a combination of two or more of these groups, where R1 to R5 each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms,
• Sp4 and Sp5 each independently represent a single bond, a linear alkylene group having 1 to 14 carbon atoms, a branched alkylene group having 3 to 14 carbon atoms, or a divalent linking group in which one or more of —CH2-'s constituting the linear alkylene group or the branched alkylene group are substituted with —O—, —S—, —NH—, —N(Q)-, or —CO—, where Q represents a substituent,
• P4 and P5 each independently represent a monovalent organic group, and at least one of P4 or P5 represents a polymerizable group,
• Ax represents at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring,
• Ay represents a hydrogen atom, an alkyl group which may have a substituent, or at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring,
• the aromatic ring in each of Ax and Ay may have a substituent, and Ax and Ay may be bonded to each other to form a ring, and
• Q3 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, which may have a substituent,
• wherein the monofunctional compound is a compound represented by Formula (II),
• P3-Sp3-(X7-Ar4)n3-(X8-Cy3)m3-X9-Ar5 (II)
• in Formula (II),
• P3 represents an acryloyloxy group or a methacryloyloxy group,
• wherein P3 includes a first terminal atom and Ar5 includes a second terminal atom of the monofunctional compound represented by Formula (II),
• wherein the first terminal atom of the monofunctional compound represented by Formula (II) is a starting atom and the second terminal atom of the monofunctional compound represented by Formula (II) is an ending atom utilized to calculate a maximum number of atoms linked together at a shortest distance to form the monofunctional compound represented by Formula (II), wherein the maximum number of atoms linked together at a shortest distance to form the monofunctional compound represented by Formula (II) is counted such that the first terminal atom and the second terminal atom are also counted;
• Sp3 represents a single bond, a linear alkylene group having 1 to 14 carbon atoms, a branched alkylene group having 3 to 14 carbon atoms, or a divalent linking group in which one or more of —CH2-'s constituting the linear alkylene group or the branched alkylene group are substituted with —O—, —S—, —NH—, —N(Q)-, or —CO—, where Q represents a substituent,
• n3 represents an integer from 0 to 2, and m3 represents 1 or 2,
• X7, X8, and X9 each independently represent a single bond;
• or —CO—, —O—, —S—, —C(═S)—, —CR1R2—, —CR3═CR4—, —NR5—, or a divalent linking group consisting of a combination of two or more of these groups, where R1 to R5 each independently represent a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms, provided that in a case where n3 is 2, a plurality of X7's may be the same as or different from each other;
• and in a case where m3 is 2, a plurality of X8's may be the same as or different from each other,
• Ar4 represents an aromatic ring which may have a substituent, provided that in a case where n3 is 2, a plurality of Ar4's may be the same as or different from each other,
• Ar5 represents a benzene ring which does not have a substituent, and
• Cy3 represents an alicyclic ring which may have a substituent, provided that in a case where m3 is 2, a plurality of Cy3's may be the same as or different from each other,
• wherein the rod-shaped liquid crystal compound and the monofunctional compound satisfy a relationship of Expression (1), and satisfy a relationship of Expression (2), and
• wherein the optically anisotropic layer exhibits a smectic phase,
• 0.2
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• 0.55
• Expression
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• Expression
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• wherein in Expression (1) a1 is the maximum number of atoms linked together between the starting atom and the ending atom at the shortest distance to form the rod-shaped liquid crystal compound represented by Formula (I), counted such that the starting atom and the ending atom are also counted;
• and
• a2 is the maximum number of atoms linked together between the starting atom and the ending atom at the shortest distance to form the monofunctional compound represented by Formula (II), counted such that the starting atom and the ending atom are also counted, and
• wherein in Expression (2), b1 is the number of substituted and unsubstituted aromatic rings present in (X1-Ar1)n1, (X3-Ar3)m0, and (Ar2—X6)n2, and the number of substituted and unsubstituted alicyclic rings present in (X2-Cy1)m1, and (Cy2-X5)m2 of Formula (I);
• and
• b2 is the number of substituted and unsubstituted aromatic rings present in (X7-Ar4)n3, and
• Ar5, and the number of substituted and unsubstituted alicyclic rings present in (X8-Cy3)m3
• of Formula (II).