Electro-optic composition, electro-optic layer, laminate, transfer film, optical waveguide, and optical modulator

Abstract

The present invention addresses the problem of providing: an electro-optic composition capable of forming an electro-optic layer exhibiting a high electro-optic constant; an electro-optic layer; a laminate; a transfer film; an optical waveguide; and an optical modulator. An electro-optic composition according to the present invention comprises: a liquid crystal compound that does not exhibit ferroelectricity; and an organic dye that has a secondary molecular sensitivity of at least 15000×10-33 esu. The liquid crystal compound exhibits nematic liquid crystallinity or smectic liquid crystallinity. The liquid crystal compound is at least one of a low molecular weight liquid crystal compound and a high molecular weight liquid crystal compound having a repeating unit L exhibiting liquid crystallinity. The low molecular weight liquid crystal compound and the high molecular weight liquid crystal compound satisfy a predetermined condition.

Description

Electro-optical composition, electro-optical layer, laminate, transfer film, optical waveguide and optical modulator

[0001] The present invention relates to an electro-optical composition, an electro-optical layer, a laminate, a transfer film, an optical waveguide, and an optical modulator.

[0002] In recent years, organic electro-optic (EO) materials have been attracting attention as materials that can be used in optical control elements (optical elements) such as optical modulators, optical switches, and optical interconnects, with the aim of realizing ultrafast optical communications.

[0003] For example, Patent Document 1 describes "a nonlinear optical material characterized by containing a ferroelectric polymer liquid crystal and a nonlinear optical compound" (see claim (1) and the like).

[0004] Japanese Patent Application Publication No. 02-179622

[0005] The present inventors have clarified that when a composition containing an organic dye together with the ferroelectric polymer liquid crystal described in Patent Document 1 is used as an organic EO material, the electro-optical constant of the formed electro-optical layer (hereinafter also abbreviated as "EO layer") is reduced.

[0006] Therefore, an object of the present invention is to provide an electro-optical composition capable of forming an electro-optical layer exhibiting a high electro-optical constant, as well as an electro-optical layer, a laminate, a transfer film, an optical waveguide, and an optical modulator.

[0007] As a result of extensive research to achieve the above object, the present inventors have found a specific liquid crystal compound that does not exhibit ferroelectricity and a liquid crystal compound having a second-order molecular susceptibility of 15000×10 －３３ The inventors have found that an EO layer exhibiting a high electro-optic constant can be formed by using an electro-optic composition containing an organic dye having a molecular weight of 1.0 or higher, and have completed the present invention. That is, the inventors have found that the above-mentioned problems can be solved by the following configuration.

[0008] [1] A liquid crystal compound that does not exhibit ferroelectricity and has a second-order molecular susceptibility of 15,000 × 10 －３３esu or more and an organic dye, wherein the liquid crystal compound exhibits nematic or smectic liquid crystallinity, and the liquid crystal compound is at least one of a low-molecular-weight liquid crystal compound and a polymeric liquid crystal compound having a repeating unit L exhibiting liquid crystallinity, and the low-molecular-weight liquid crystal compound and the polymeric liquid crystal compound satisfy condition (1) described below. [2] The electro-optical composition according to [1], wherein the low-molecular-weight liquid crystal compound and the polymeric liquid crystal compound satisfy condition (2) described below. [3] The electro-optical composition according to [1] or [2], wherein the content of the organic dye relative to the content of the low-molecular-weight liquid crystal compound and the content of the repeating unit L of the polymeric liquid crystal compound is a mass ratio of 0.6 or less. [4] The electro-optical composition according to any of [1] to [3], wherein a monomer forming the repeating unit L of the low-molecular-weight liquid crystal compound or the polymeric liquid crystal compound is a compound represented by formula (3) described below. [5] The electro-optical composition according to [4], wherein the electron-withdrawing group represented by at least one of E1 and E2 in formula (3) below and the optional substituent that M may have is a group represented by any one of formulas (EA-1) to (EA-33) below. [6] The electro-optical composition according to any one of [1] to [5], wherein the content of the organic dye is 5 mass % or more relative to the total mass of the solid content of the electro-optical composition. [7] The electro-optical composition according to any one of [1] to [6], wherein the organic dye has a molecular aspect ratio of 2.0 or more. [8] The electro-optical composition according to any one of [1] to [7], wherein the organic dye has an angle θeg formed between the vector of the molecular long axis and the vector of the transition dipole moment of 10.0° or less. [9] An electro-optical layer, obtained by fixing the alignment state of a liquid crystal compound contained in the electro-optical composition according to any one of [1] to [8].

[10] The electro-optical layer according to [9], wherein the organic dye contained in the electro-optical layer has a degree of alignment of 0.3 or more.

[11] A laminate having an alignment layer and the electro-optical layer according to [9] or

[10] arranged on the alignment layer.

[12] A transfer film having a temporary support, an alignment layer, and the electro-optical layer according to [9] or

[10] in this order.

[13] An optical waveguide having a core layer and a clad layer, wherein the core layer is the electro-optic layer according to [9] or

[10] .

[14] An optical modulator having the optical waveguide according to

[13] .

[0009] As will be described below, the present invention can provide an electro-optical composition capable of forming an electro-optical layer exhibiting a high electro-optical constant, as well as an electro-optical layer, a laminate, a transfer film, an optical waveguide, and an optical modulator.

[0010] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the upper and lower limits. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with the upper or lower limit of another stepwise manner. In this specification, the upper or lower limit of a numerical range described in a stepwise manner may be replaced with a value shown in the Examples. In this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. Here, when two or more substances are used in combination for each component, the content of the component refers to the total content of the substances used in combination, unless otherwise specified. In this specification, the bond direction of the divalent group (e.g., -O-CO-) described is not particularly limited, and examples include "L １ -L ２ -L ３ In the bond ２ When is —O—CO—, L １ The position where it is bonded to the side is *1, L ３ If the position bonded to the side is *2, then L ２ may be *1-O-CO-*2 or *1-CO-O-*2.

[0011] In addition, in this specification, "(meth)acrylate" is a notation representing "acrylate" or "methacrylate", "(meth)acrylic" is a notation representing "acrylic" or "methacrylic", and "(meth)acryloyl" is a notation representing "acryloyl" or "methacryloyl".

[0012] In this specification, examples of the substituent (monovalent substituent) include the substituents described below in Substituent Group A. In this specification, the phrase "optionally having a substituent" includes not only an embodiment in which no substituent is present, but also an embodiment in which one or more substituents are present. <Substituent Group A> Examples of the substituent include halogen atoms (for example, fluorine atoms, chlorine atoms, and bromine atoms, preferably chlorine atoms and fluorine atoms, and more preferably fluorine atoms); alkyl groups (preferably alkyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as linear alkyl groups having 1 to 6 carbon atoms (for example, methyl groups, ethyl groups, n-propyl groups, n-butyl groups, n-pentyl groups, and n-hexyl groups), branched alkyl groups having 3 to 6 carbon atoms (for example, isopropyl groups, isobutyl groups, tert-butyl groups, sec-butyl groups, neopentyl groups, isohexyl groups, and 3-methylpentyl groups), and cyclic alkyl groups having 3 to 12 carbon atoms (for example, cyclopropyl groups, cyclopentyl groups, cyclohexyl groups, 1-norbornyl groups, and 1-adamantyl groups)); alkenyl groups (preferably alkenyl groups having 2 to 48 carbon atoms, more preferably 2 to 18 carbon atoms, such as vinyl groups, allyl groups, 1-butenyl groups, and 2-butenyl groups); alkynyl groups (preferably alkynyl groups having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, such as ethynyl groups, 1-propynyl groups, propargyl groups, 1-butynyl groups, and 2-butynyl groups); aryl groups (preferably aryl groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, such as phenyl groups, oligoaryl groups (naphthyl groups, anthryl groups), phenanthrenyl groups, fluorenyl groups, pyrenyl groups, triphenylenyl groups, and biphenyl groups); Heteroaryl groups (preferably heterocyclic groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a 2-thienyl group, a 4-pyridyl group, a 2-furyl group, a 2-pyrimidinyl group, a 1-pyridyl group, a 2-benzothiazolyl group, a 1-imidazolyl group, a 1-pyrazolyl group, or a benzotriazol-1-yl group);arylalkyl groups (preferably arylalkyl groups having 7 to 15 carbon atoms, for example, benzyl group, phenethyl group, methylbenzyl group, phenylpropyl group, 1-methylphenylethyl group, phenylbutyl group, 2-methylphenylpropyl group, tetrahydronaphthyl group, naphthylmethyl group, naphthylethyl group, indenyl group, fluorenyl group, anthracenylmethyl group (anthrylmethyl group), phenanthrenylmethyl group (phenanthrylmethyl group)); silyl groups (preferably silyl groups having 3 to 38 carbon atoms, more preferably 3 to 18 carbon atoms, for example, trimethylsilyl group, triethylsilyl group, tributylsilyl group, t-butyldimethylsilyl group, t-hexyldimethylsilyl group); hydroxy groups; cyano groups; nitro groups; morpholino groups; Alkoxy groups (preferably alkoxy groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methoxy, ethoxy, 1-butoxy, 2-butoxy, isopropoxy, t-butoxy, dodecyloxy, and cycloalkyloxy groups (for example, cyclopentyloxy and cyclohexyloxy)); aryloxy groups (preferably aryloxy groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, phenoxy and 1-naphthoxy); alkenyloxy groups (preferably alkenyloxy groups having 2 to 6 carbon atoms, for example, vinyloxy, 1-propenyloxy, 2-n-propenyloxy (allyloxy), 1-n-butenyloxy, and prenyloxy); heterocyclic oxy groups (preferably heterocyclic oxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a 1-phenyltetrazole-5-oxy group or a 2-tetrahydropyranyloxy group); silyloxy groups (preferably silyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, such as a trimethylsilyloxy group, a t-butyldimethylsilyloxy group or a diphenylmethylsilyloxy group); acyloxy groups (preferably acyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, such as an acetoxy group, a pivaloyloxy group, a benzoyloxy group, a dodecanoyloxy group, an acryloyloxy group or a methacryloyloxy group);hydroxyalkyleneoxy groups (preferably hydroxyalkyleneoxy groups having 2 to 10 carbon atoms, for example, a hydroxyethyleneoxy group); alkoxycarbonyloxy groups (preferably alkoxycarbonyloxy groups having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, an ethoxycarbonyloxy group, a t-butoxycarbonyloxy group, or a cycloalkyloxycarbonyloxy group (for example, a cyclohexyloxycarbonyloxy group)); aryloxycarbonyloxy groups (preferably aryloxycarbonyloxy groups having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, for example, a phenoxycarbonyloxy group); carbamoyloxy groups (preferably carbamoyloxy groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, an N,N-dimethylcarbamoyloxy group, an N-butylcarbamoyloxy group, an N-phenylcarbamoyloxy group, or an N-ethyl-N-phenylcarbamoyloxy group); sulfamoyloxy groups (preferably sulfamoyloxy groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, such as an N,N-diethylsulfamoyloxy group or an N-propylsulfamoyloxy group); alkylsulfonyloxy groups (preferably alkylsulfonyloxy groups having 1 to 38 carbon atoms, more preferably 1 to 24 carbon atoms, such as a methylsulfonyloxy group, a hexadecylsulfonyloxy group or a cyclohexylsulfonyloxy group); arylsulfonyloxy groups (preferably arylsulfonyloxy groups having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, such as a phenylsulfonyloxy group); acyl groups (preferably acyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as a formyl group, an acetyl group, an acryloyl group, a methacryloyl group, a pivaloyl group, a benzoyl group, a tetradecanoyl group or a cyclohexanoyl group); an alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, a methoxycarbonyl group, an ethoxycarbonyl group, an octadecyloxycarbonyl group, a cyclohexyloxycarbonyl group, or a 2,6-di-tert-butyl-4-methylcyclohexyloxycarbonyl group);an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, such as a phenoxycarbonyl group); a carbamoyl group (preferably a carbamoyl group having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, such as a carbamoyl group, N,N-diethylcarbamoyl group, N-ethyl-N-octylcarbamoyl group, N,N-dibutylcarbamoyl group, N-propylcarbamoyl group, N-phenylcarbamoyl group, N-methyl-N-phenylcarbamoyl group, or N,N-dicyclohexylcarbamoyl group); an amino group (preferably an amino group having 32 or less carbon atoms, more preferably 24 or less carbon atoms, such as an amino group, methylamino group, N,N-dimethylamino group, N,N-dibutylamino group, tetradecylamino group, 2-ethylhexylamino group, or cyclohexylamino group); anilino group (preferably an anilino group having 6 to 32 carbon atoms, more preferably 6 to 24 carbon atoms, for example, an anilino group, an N-methylanilino group); heterocyclic amino group (preferably a heterocyclic amino group having 1 to 32 carbon atoms, more preferably 1 to 18 carbon atoms, for example, a 4-pyridylamino group); carbonamido group (preferably a carbonamido group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, an acetamido group, a benzamido group, a tetradecanamido group, a pivaloylamido group, a cyclohexanamido group); ureido group (preferably a ureido group having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a ureido group, an N,N-dimethylureido group, an N-phenylureido group); imido group (preferably an imido group having 36 or less carbon atoms, more preferably 24 or less carbon atoms, for example, an N-succinimido group, an N-phthalimido group); an alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 48 carbon atoms, more preferably 2 to 24 carbon atoms, for example, a methoxycarbonylamino group, an ethoxycarbonylamino group, a t-butoxycarbonylamino group, an octadecyloxycarbonylamino group, or a cyclohexyloxycarbonylamino group); an aryloxycarbonylamino group (preferably an aryloxycarbonylamino group having 7 to 32 carbon atoms, more preferably 7 to 24 carbon atoms, for example, a phenoxycarbonylamino group);sulfonamido groups (preferably sulfonamido groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methanesulfonamido groups, butanesulfonamido groups, benzenesulfonamido groups, hexadecanesulfonamido groups, and cyclohexanesulfonamido groups); sulfamoylamino groups (preferably sulfamoylamino groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, N,N-dipropylsulfamoylamino groups, and N-ethyl-N-dodecylsulfamoylamino groups); azo groups (preferably azo groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, phenylazo groups and 3-pyrazolylazo groups); alkylthio groups (preferably alkylthio groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methylthio groups, ethylthio groups, octylthio groups, and cyclohexylthio groups); an arylthio group (preferably an arylthio group having 6 to 48 carbon atoms, more preferably an arylthio group having 6 to 24 carbon atoms, for example, a phenylthio group); a heterocyclic thio group (preferably a heterocyclic thio group having 1 to 32 carbon atoms, more preferably a heterocyclic thio group having 1 to 18 carbon atoms, for example, a 2-benzothiazolylthio group, a 2-pyridylthio group, or a 1-phenyltetrazolylthio group); an alkylsulfinyl group (preferably an alkylsulfinyl group having 1 to 32 carbon atoms, more preferably an alkylsulfinyl group having 1 to 24 carbon atoms, for example, a dodecanesulfinyl group); an arylsulfinyl group (preferably an arylsulfinyl group having 6 to 32 carbon atoms, more preferably an arylsulfinyl group having 6 to 24 carbon atoms, for example, a phenylsulfinyl group); alkylsulfonyl groups (preferably alkylsulfonyl groups having 1 to 48 carbon atoms, more preferably 1 to 24 carbon atoms, for example, methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, isopropylsulfonyl, 2-ethylhexylsulfonyl, hexadecylsulfonyl, octylsulfonyl, and cyclohexylsulfonyl groups); arylsulfonyl groups (preferably arylsulfonyl groups having 6 to 48 carbon atoms, more preferably 6 to 24 carbon atoms, for example, phenylsulfonyl, and 1-naphthylsulfonyl groups);sulfamoyl groups (preferably sulfamoyl groups having 32 or less carbon atoms, more preferably 24 or less carbon atoms, for example, a sulfamoyl group, an N,N-dipropylsulfamoyl group, an N-ethyl-N-dodecylsulfamoyl group, an N-ethyl-N-phenylsulfamoyl group, an N-cyclohexylsulfamoyl group, or an N-(2-ethylhexyl)sulfamoyl group); phosphonyl groups (preferably phosphonyl groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a phenoxyphosphonyl group, an octyloxyphosphonyl group, or a phenylphosphonyl group); phosphinoylamino groups (preferably phosphinoylamino groups having 1 to 32 carbon atoms, more preferably 1 to 24 carbon atoms, for example, a diethoxyphosphinoylamino group, or a dioctyloxyphosphinoylamino group); epoxy groups; —NHCOCH; ３ ;-SO ２ NHC ２ H ４ OCH ３ ;-NHSO ２ CH ３ and the like, and two or more of these may be combined. These substituents may be further substituted with other substituents. When two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

[0013] [Electro-optical composition] The electro-optical composition of the present invention (hereinafter also simply referred to as "the composition of the present invention") is a liquid crystal compound that does not exhibit ferroelectricity and a liquid crystal compound having a second-order molecular susceptibility of 15000×10 －３３esu or higher organic dye. The liquid crystal compound contained in the composition of the present invention exhibits nematic or smectic liquid crystallinity. The liquid crystal compound contained in the composition of the present invention is at least one of a low-molecular-weight liquid crystal compound and a polymeric liquid crystal compound having a repeating unit L that exhibits liquid crystallinity. In the composition of the present invention, the low-molecular-weight liquid crystal compound and the polymeric liquid crystal compound (the repeating unit L in the case of the polymeric liquid crystal compound) satisfy the following condition (1) in terms of the relationship between the molar fraction and the dipole moment. In the following description, low-molecular-weight liquid crystal compounds and polymeric liquid crystal compounds that do not exhibit ferroelectricity, exhibit nematic or smectic liquid crystallinity, and satisfy the following condition (1) in terms of the relationship between the molar fraction and the dipole moment are also referred to as "specific liquid crystal compounds."

[0014] In the present invention, as described above, the specific liquid crystal compound and the second-order molecular susceptibility are 15000×10 －３３ By using an electro-optical composition containing an organic dye having a molecular weight of 15000×10 or more, an EO layer exhibiting a high electro-optical constant can be formed. The reason for this effect is not clear in detail, but the inventors speculate as follows. First, the second-order molecular susceptibility is 15000×10 －３３ Organic dyes of .esu or higher generally have an electron-donating moiety and an electron-withdrawing moiety, and therefore can be said to have a structure with a large dipole moment. Furthermore, the specific liquid crystal compound incorporated as the liquid crystal compound can be said to have a structure with a large dipole moment because the relationship between the molar fraction and the dipole moment satisfies the condition (1) described below. Therefore, in the present invention, it is believed that the dipole-dipole interaction between the specific liquid crystal compound and the organic dye is strengthened, and as a result, aggregation of the organic dye can be suppressed, thereby forming an EO layer exhibiting a high electro-optic constant. The specific liquid crystal compound and organic dye contained in the composition of the present invention will be described in detail below.

[0015] [Liquid Crystal Compound] The specific liquid crystal compound contained in the composition of the present invention is a liquid crystal compound that does not exhibit ferroelectricity. Ferroelectricity refers to the ability to maintain electric polarization even in the absence of an external electric field and to reverse the polarity of electric polarization in response to an external electric field. In the present invention, the presence or absence of ferroelectricity is determined using the following method and evaluation criteria. <Measurement of Polarization Reversal and Residual Polarization> A liquid crystal compound is sealed in an 8 μm gap liquid crystal cell (manufactured by EHC Corporation) with glass substrates with indium tin oxide (ITO) on the top and bottom. In the liquid crystal phase of the sealed liquid crystal compound, a triangular wave of 80 Hz, offset voltage 0 V, and amplitude ±10 V is applied to the cell, and the polarization reversal current and electric flux density corresponding to the applied voltage are measured. The spontaneous polarization Ps is calculated from the area of ​​the polarization reversal peak, and the remanent polarization Pr is calculated from the value of the electric flux density when the electric field becomes zero. The presence or absence of ferroelectricity is determined using the following evaluation criteria. <Evaluation Criteria> Ferroelectricity: Both spontaneous polarization Ps and remnant polarization Pr are calculated. No ferroelectricity: At least one of spontaneous polarization Ps and remnant polarization Pr is not calculated.

[0016] The specific liquid crystal compound contained in the composition of the present invention is a liquid crystal compound exhibiting nematic or smectic liquid crystallinity. Here, "liquid crystal compound exhibiting nematic liquid crystallinity" refers to a liquid crystal compound capable of exhibiting a nematic liquid crystal state. The nematic phase refers to a state in which the constituent molecules have orientational order but do not have three-dimensional positional order. The "liquid crystal compound exhibiting smectic liquid crystallinity" refers to a liquid crystal compound capable of exhibiting a smectic liquid crystal state. The smectic phase refers to a state in which molecules aligned in one direction have a layer structure.

[0017] The specific liquid crystal compound contained in the composition of the present invention is at least one of a low molecular weight liquid crystal compound and a polymer liquid crystal compound having a repeating unit L that exhibits liquid crystallinity. That is, the composition of the present invention may contain only a low molecular weight liquid crystal compound or a polymer liquid crystal compound, or may contain both a low molecular weight liquid crystal compound and a polymer liquid crystal compound. The low molecular weight liquid crystal compound and the polymer liquid crystal compound may each be used alone or in combination of two or more. Here, "low molecular weight liquid crystal compound" refers to a liquid crystal compound that does not have a repeating unit in its chemical structure. Furthermore, "polymer liquid crystal compound" refers to a liquid crystal compound that has a repeating unit in its chemical structure, and in the present invention, refers to a liquid crystal compound having a repeating unit L that exhibits liquid crystallinity. The weight-average molecular weight (Mw) of the polymer liquid crystal compound is not particularly limited, but is preferably 5,000 to 500,000, more preferably 7,000 to 300,000, and even more preferably 10,000 to 200,000. Here, the weight-average molecular weight in the present invention is a value measured by gel permeation chromatography (GPC) under the following conditions. Solvent (eluent): THF (tetrahydrofuran) Apparatus name: TOSOH HLC-8320GPC Column: Three TOSOH TSKgel Super HZM-H (4.6 mm x 15 cm) connected together Column temperature: 40°C Sample concentration: 0.1% by mass Flow rate: 1.0 ml / min Calibration curve: A calibration curve using seven samples of TSK standard polystyrene manufactured by TOSOH with Mw = 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06) was used.

[0018] In the present invention, the low molecular weight liquid crystal compound and the polymer liquid crystal compound satisfy the following condition (1) as described above. However, it is preferable that they satisfy the following condition (2) because this allows the formation of an EO layer exhibiting a higher electro-optical constant: Σ(xi×μi)≧5 (1) Σ(xi×μi)≧7 (2) In the above formulas (1) and (2), xi represents the molar fraction of the low molecular weight liquid crystal compound and the repeating unit L of the i-th component among the repeating units L contained in the low molecular weight liquid crystal compound and the polymer liquid crystal compound contained in the electro-optical composition. μi represents the dipole moment of the low molecular weight liquid crystal compound and the repeating unit L of the i-th component. Note that when the polymer liquid crystal compound has repeating units that do not exhibit liquid crystallinity (hereinafter also abbreviated as "other repeating units"), the other repeating units are not taken into account in calculating Σ(xi×μi). The dipole moment is a value calculated by the density functional method using the quantum chemistry calculation program Gaussian 16 under the following conditions: Functional: Cam-b3lyp Basis function: 6-31G(d) Solvent effect: acetonitrile Other conditions: Polar

[0019] Next, the calculation method for Σ(xi×μi) will be described in detail. First, when the composition of the present invention contains, for example, one type of low molecular weight liquid crystal compound and a polymeric liquid crystal compound having two types of repeating units L (referred to as "repeating unit L1" and "repeating unit L2" in this paragraph, respectively) and one other repeating unit, the objects to be calculated by Σ(xi×μi) are the three components: the low molecular weight liquid crystal compound, the repeating unit L1, and the repeating unit L2. The molar fractions of the low molecular weight liquid crystal compound, the repeating unit L1, and the repeating unit L2 (i.e., x1 to x3) refer to the ratio of the number of moles of each component when the total number of moles calculated from the respective blend amounts (mass) is taken as 1. The dipole moments of the low molecular weight liquid crystal compound, the repeating unit L1, and the repeating unit L2 (i.e., μ1 to μ3) refer to values ​​calculated using the program and conditions described above. Therefore, in the above example, Σ(xi×μi) can be calculated from “x1μ1+x2μ2+x3μ3”.

[0020] In the present invention, examples of low molecular weight liquid crystal compounds include the liquid crystal compounds described in paragraphs

[0072] to

[0088] of JP 2013-228706 A, and among these, liquid crystal compounds exhibiting smectic properties are preferred. Examples of polymer liquid crystal compounds include the thermotropic liquid crystal polymers described in JP 2011-237513 A, and the polymer liquid crystal compounds described in paragraphs

[0012] to

[0042] of WO 2018 / 199096 A. Examples of such liquid crystal compounds include those described in paragraphs

[0019] to

[0140] of WO 2022 / 014340 A, and the descriptions thereof are incorporated herein by reference.

[0021] Furthermore, in the present invention, because an EO layer exhibiting a higher electro-optical constant can be formed, it is preferable that the monomer forming the repeating unit L of the low-molecular-weight liquid crystal compound or the polymer liquid crystal compound is a compound represented by the following formula (3): E1-(L1-M)n-L2-E2 (3) In the above formula (3), n represents an integer of 2 or greater. M represents an aromatic ring which may have a substituent. Multiple Ms may be the same or different. L1 and L2 each independently represent a single bond or a divalent linking group. Multiple L1s may be the same or different. E1 and E2 each independently represent a hydrogen atom, an electron-withdrawing group, or a polymerizable group. However, with respect to the monomer, at least one of E1 and E2 represents a polymerizable group. At least one of E1, E2, and the substituents which M may have represents an electron-withdrawing group.

[0022] In the above formula (3), n represents an integer of 2 or more, preferably an integer of 2 to 5, more preferably an integer of 2 to 4, and even more preferably 2 or 3.

[0023] Examples of the aromatic ring represented by M in the above formula (3) include aromatic rings having 6 to 20 carbon atoms, and specific examples include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring; and aromatic heterocycles such as a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring. Furthermore, examples of the substituent that M may have include the substituents described in the above-mentioned substituent group A, and among these, a substituent corresponding to an electron-withdrawing group is preferred. Examples of the electron-withdrawing group include those described in one embodiment of E1 and E2 below.

[0024] Examples of the divalent linking group represented by one embodiment of L1 and L2 in the above formula (3) include -CO-, -O-, -S-, -C(=S)-, -CR １ R ２ -, -CR ３ =CR ４ -, -CR ３ =N-, -C≡C-, -N=N-, -NR ５ -, or a divalent linking group formed by a combination of two or more thereof, specifically, -CO-, -O-, -CO-O-, -C(=S)O-, -CR １ R ２ -, -CR １ R ２ -CR １ R ２ -, -O-CR １ R ２ -, -CR １ R ２ -O-CR １ R ２ -, -CO-O-CR １ R ２ -, -O-CO-CR １ R ２ -, -CR １ R ２ -O-CO-CR １ R ２ -, -CR １ R ２ -CO-O-CR １ R ２ -, -NR ５ -CR １ R ２ -, and -CO-NR５ -, etc. Here, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. L1 and L2 are preferably any of a single bond, —CO—, —O—, and —CO—O—.

[0025] Examples of the polymerizable group represented by one embodiment of E1 and E2 in the above formula (3) include groups represented by the following formulas (P-1) to (P-30): As described above, when the monomer forming the repeating unit L of the polymer liquid crystal compound is a compound represented by the above formula (3), at least one of E1 and E2 represents a polymerizable group.

[0026]

[0027] In the above formulas (P-1) to (P-30), * represents the bonding position with L1 (M when L1 is a single bond) or L2 (M when L2 is a single bond) in the above formula (3). Ｐis a hydrogen atom, a halogen atom, a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, an aryl group having 1 to 20 carbon atoms, a heterocyclic group (which may also be called a heterocyclic group), a cyano group, a hydroxy group, a nitro group, a carboxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an ammonio group, an acylamino group, an aminocarbonylamino group, Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imido group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (-B(OH) ２ ), phosphato group (—OPO(OH) ２ ), or a sulfato group (—OSO ３ H), and a plurality of R Ｐ may be the same or different.

[0028] Examples of the electron-withdrawing group represented by one embodiment of E1 and E2 in formula (3) above include any of the groups represented by the following formulae: As described above, at least one of the substituents that E1, E2, and M may have represents an electron-withdrawing group, and examples thereof include groups represented by any of formulae (EA-1) to (EA-52) below, and among these, groups represented by any of formulae (EA-1) to (EA-33) below are preferred.

[0029]

[0030] In the above formulas (EA-1) to (EA-52) representing electron-withdrawing groups, * represents a bonding position. R represents a hydrogen atom or a substituent. na represents an integer of 0 to 5, and when na represents an integer of 2 to 5, multiple Rs may be the same or different. X represents -C(R Ｅ１１ ) (R Ｅ１２ )-, -C(=O)-, -C(=S)-, or -C(=NR Ｅ１３ )-. Ｅ１１ and R Ｅ１２ each independently represents a hydrogen atom, a halogen atom, an alkyl group, a fluoroalkyl group, an aryl group, a cyano group, or a nitro group, and —CH ２ - may be substituted with a divalent linking group, and the hydrogen atoms of the alkyl group and aryl group may be substituted with a substituent. Ｅ１３ represents a hydrogen atom or an alkyl group, and —CH ２ - may be substituted with a divalent linking group. Y is -O-, -S-, -N(R Ｅ１４ )- or -S(=O)-. Ｅ１４ represents a hydrogen atom, or an alkyl group, aryl group, alkylcarbonyl group, arylcarbonyl group, alkylsulfonyl group, or arylsulfonyl group, each of which may have a substituent. Z represents -C(H)= or -N=.

[0031] Examples of the substituent represented by one embodiment of R in the above formula representing the electron-withdrawing group include the substituents described in the above-mentioned Substituent Group A. R in the above formula is preferably a hydrogen atom or an alkyl group.

[0032] As described above, X in the above formula representing an electron-withdrawing group is —C(R Ｅ１１ ) (R Ｅ１２ )-, -C(=O)-, -C(=S)-, or -C(=NR Ｅ１３ )-, where R Ｅ１１ and RＥ１２ each independently represents a hydrogen atom, a halogen atom, an alkyl group, a fluoroalkyl group, an aryl group, a cyano group, or a nitro group, and —CH ２ - may be substituted with a divalent linking group, and the hydrogen atoms of the alkyl group and aryl group may be substituted with a substituent. ２ Examples of the divalent substituent substituting - include the same as the divalent linking group represented by one embodiment of L1 and L2, and examples of the substituent substituting a hydrogen atom include the substituents described in the above-mentioned Substituent Group A. Ｅ１３ represents a hydrogen atom or an alkyl group, and —CH ２ - may be substituted with a divalent linking group. ２ Examples of the divalent substituent substituting - include the same as the divalent linking group represented by one embodiment of L1 and L2.

[0033] As described above, Y in the above formula representing an electron-withdrawing group is —O—, —S—, —N(R Ｅ１４ )- or -S(=O)-. Ｅ１４ represents a hydrogen atom, or an alkyl group, an aryl group, an alkylcarbonyl group, an arylcarbonyl group, an alkylsulfonyl group, or an arylsulfonyl group, which may have a substituent. Examples of the substituent that the alkyl group or the like may have include the substituents described in the above-mentioned substituent group A.

[0034] In the present invention, examples of the polymeric liquid crystal compound having a repeating unit L that exhibits liquid crystallinity include polymers having a repeating unit L1 represented by the following formula (L1).

[0035] In the above formula (L1), R Ｂ１ represents a hydrogen atom or a substituent, and X represents —O—, —S—, or —NR Ｂ２ represents -, and R Ｂ２ represents a hydrogen atom or a substituent. Ｂ１ and L Ｂ２each independently represents a single bond or a divalent linking group. Mes represents a mesogen group represented by formula (M) described later. T Ｂ１ represents a hydrogen atom or a substituent, and may be linked to the main chain of another polymeric liquid crystal compound.

[0036] In the above formula (L1), R Ｂ１ represents a hydrogen atom or a substituent. Ｂ１ Examples of the substituent represented by one embodiment of R include the substituents described in the above-mentioned Substituent Group A. Ｂ１ is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group.

[0037] In the above formula (L1), X is —O—, —S—, or —NR Ｂ２ represents -, and R Ｂ２ represents a hydrogen atom or a substituent. Ｂ２ Examples of the substituent represented by one embodiment of R include the substituents described in the above-mentioned Substituent Group A. Ｂ２ is preferably a hydrogen atom or an alkyl group. X is preferably —O— or —NR Ｂ２ It is preferably —, more preferably —O— or —NH—, and further preferably —O—.

[0038] In the above formula (L1), L Ｂ１ and L Ｂ２ each independently represents a single bond or a divalent linking group. Ｂ１ and L Ｂ２Examples of the divalent linking group represented by one embodiment of the formula (I) include a divalent aliphatic hydrocarbon group which may have a substituent, -O-, -S-, -N(Q)-, -CO-, or a group formed by combining these. Q represents a hydrogen atom or a substituent. Examples of the divalent aliphatic hydrocarbon group include an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 1 to 10 carbon atoms, and an alkynylene group having 1 to 10 carbon atoms. Furthermore, examples of groups formed by combining these include groups formed by combining at least two or more groups selected from the group consisting of the above-mentioned divalent aliphatic hydrocarbon groups, -O-, -S-, -N(Q)-, and -CO-, and examples thereof include the divalent aliphatic hydrocarbon group -O- and the divalent hydrocarbon group -N(Q)-. L Ｂ１ L is preferably a divalent linking group formed by combining at least two or more groups selected from the group consisting of an optionally substituted linear alkylene group having 1 to 10 carbon atoms, an optionally substituted branched alkylene group having 3 to 10 carbon atoms, an optionally substituted cyclic alkylene group having 3 to 10 carbon atoms, -O-, and -N(Q)-, and more preferably a divalent linking group formed by combining at least two or more groups selected from the group consisting of an optionally substituted linear alkylene group having 1 to 10 carbon atoms, an optionally substituted cyclic alkylene group having 3 to 10 carbon atoms, -O-, and -NH-. Ｂ２ is preferably a single bond. Examples of the substituent that the divalent aliphatic hydrocarbon group may have and the substituent represented by one embodiment of Q include the substituents described in the above-mentioned Substituent Group A.

[0039] In the above formula (B), Mes represents a mesogen group represented by the following formula (M). In the formula (M), * represents a bonding position, and m represents an integer of 2 or more. １１ and Ph １２ each independently represents an aromatic ring, and a plurality of Ph １１ may be the same or different. １１ represents a single bond or a divalent linking group, and a plurality of L １１may be the same or different.

[0040] Ph in the above formula (M) １１ and Ph １２ Examples of the aromatic ring represented by the formula (I) include aromatic rings having 6 to 20 carbon atoms, and specific examples thereof include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring; and aromatic heterocycles such as a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring.

[0041] In the above formula (M), n represents an integer of 2 or more, preferably an integer of 2 to 5, more preferably an integer of 2 to 4, and even more preferably 2 or 3.

[0042] L in the above formula (M) １１ Examples of the divalent linking group represented by one embodiment of the formula (I) include -CO-, -O-, -S-, -C(=S)-, and -CR １ R ２ -, -CR ３ =CR ４ -, -CR ３ =N-, -C≡C-, -N=N-, -NR ５ or a divalent linking group formed by a combination of two or more thereof, specifically, —CO—, —O—, —CO—O—, —C(═S)O—, —CR １ R ２ -, -CR １ R ２ -CR １ R ２ -, -O-CR １ R ２ -, -CR １ R ２ -O-CR １ R ２ -, -CO-O-CR １ R ２ -, -O-CO-CR １ R ２ -, -CR １ R ２ -O-CO-CR １ R ２ -, -CR １ R ２ -CO-O-CR １ R２ -, -NR ５ -CR １ R ２ -, and -CO-NR ５ -, etc. Here, R １ ~R ５ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. １１ is preferably any one of a single bond, —CO—, —O—, and —CO—O—.

[0043] In the above formula (L1), T Ｂ１ represents a hydrogen atom or a substituent, and may be linked to the main chain of another polymer liquid crystal compound. Ｂ１ Examples of the substituent represented by one embodiment of the formula (I) include the substituents described in the above-mentioned Substituent Group A, as well as the above-mentioned polymerizable groups and electron-withdrawing groups.

[0044] Specific examples of the repeating unit L1 represented by the above formula (L1) include the following.

[0045] In the composition of the present invention, the content of the specific liquid crystal compound described above is not particularly limited, but is preferably 40 to 95% by mass, more preferably 50 to 90% by mass, based on the total mass of the solid content of the composition.

[0046] [Organic Dye] The organic dye contained in the composition of the present invention has a second-order molecular susceptibility of 15,000×10 －３３ esu or higher (hereinafter also referred to as "specific organic dye"), －３３ esu or more 10000×10 －３０esu or less. As such an organic dye, any organic dye known in the art as an EO material can be used. Here, the second-order molecular susceptibility of the organic dye refers to a value calculated by the density functional method under the following conditions using the quantum chemical calculation program Gaussian 16. Functional: Cam-b3lyp Basis function: 6-31+G(d,p) Solvent effect: None Other conditions: Polar, IOP (8 / 11=1)

[0047] In the present invention, because an EO layer exhibiting a higher electro-optical constant can be formed, the aspect ratio of the molecule of the specific organic dye is preferably 2.0 or more, more preferably 2.0 to 4.0, and even more preferably 2.5 to 3.5. Here, the aspect ratio of the molecule of the specific organic dye refers to a value calculated using the simulation software Winmostar V11.4.3 (manufactured by CrossAbility) after determining the most stable three-dimensional structure of the specific organic dye under the following conditions using Winmostar V11.4.3 (manufactured by CrossAbility). Hamiltonian: AM1 Method: EF MM: MMOK GNORM: 0.05

[0048] Furthermore, in the present invention, because an EO layer exhibiting a higher electro-optic constant can be formed, the angle θeg (hereinafter also abbreviated as "θeg") between the vector of the molecular long axis and the vector of the transition dipole moment in the specific organic dye is preferably 10.0° or less, more preferably 8.0° or less, and even more preferably 5.0° or less. The lower limit of θeg is not particularly limited, but is preferably 0°. Here, θeg refers to a value calculated using the following procedure and method. First, the most stable conformation of the specific organic dye is determined under the same conditions as in the calculation of the aspect ratio described above. Then, the excited state energy of the specific organic dye is calculated using the quantum chemistry calculation program Gaussian 16 by density functional theory under the following conditions: Functional: Cam-b3lyp Basis function: 6-31G(d) Solvent effect: ethyl acetate Other conditions: td = (nate = 16, root = 0) Next, using the simulation software Winmostar V11.4.3 (manufactured by CrossAbility), the molecular long axis vector (Mx, My, Mz) and transition dipole moment vector (Tx, Ty, Tz) of the specific organic dye are calculated. Note that when multiple transition dipole moments exist, the transition dipole moment vector with the largest absorption wavelength is used to calculate θeg. Next, θeg is calculated according to the following formulas (A) to (D). (A) Lm = (Mx^2 + My^2 + Mz^2)^(1 / 2) (B) Lt = (Tx^2 + Ty^2 + Tz^2)^(1 / 2) (C) θeg = acos((Mx x Tx + My x Ty + Mz x Tz) / (Lm x Lt)) Here, Lm represents the magnitude of the molecular long axis vector, and Lt represents the magnitude of the transition dipole moment vector. Furthermore, if the calculated angle exceeds 90°, the calculated angle is subtracted from 180° to adjust it so that it is in the range of 0° or more and less than 90°, and this value is defined as θeg.

[0049] In the present invention, the content of the low molecular weight liquid crystal compound and the content of the repeating unit L of the high molecular weight liquid crystal compound (hereinafter referred to as "W") can be adjusted to form an EO layer exhibiting a higher electro-optical constant. Ｌ The content of the specific organic dye (hereinafter referred to as "WＥ ") is the mass ratio (hereinafter referred to as "W Ｅ / W Ｌ ") is preferably 0.6 or less, more preferably less than 0.50, and even more preferably 0.40 or less. Ｅ / W Ｌ The lower limit of W is not particularly limited, but is preferably 0.02 or more, and more preferably 0.10 or more. Ｌ ) refers to the content of low molecular weight liquid crystal compounds when the liquid crystal compound is only a low molecular weight liquid crystal compound, refers to the content of repeating units L of polymer liquid crystal compounds when the liquid crystal compound is only a polymer liquid crystal compound, and refers to the total content of low molecular weight liquid crystal compounds and the content of repeating units L of polymer liquid crystal compounds when the liquid crystal compound is a mixture of low molecular weight liquid crystal compounds and polymer liquid crystal compounds.

[0050] In the present invention, the content of the specific organic dye is preferably 5% by mass or more, more preferably 10% by mass or more, relative to the total mass of the solid contents of the electro-optical composition, because this allows the formation of an EO layer exhibiting a higher electro-optical constant. The upper limit of the content of the specific organic dye relative to the total mass of the solid contents of the electro-optical composition is preferably less than 50% by mass, more preferably 40% by mass or less.

[0051] [Vertical Alignment Agent] The composition of the present invention preferably contains a vertical alignment agent. Here, the vertical alignment agent refers to an additive that has the function of aligning the above-mentioned liquid crystal compound in a direction perpendicular to the main plane of the electro-optical layer. Note that "vertical alignment" does not require alignment at a strict 90° angle, but means alignment at an angle of 70 to 110°.

[0052] Examples of the vertical alignment agent include an ionic vertical alignment agent and a vertical alignment agent having a boronic acid group, and it is preferable to use an ionic vertical alignment agent and a vertical alignment agent having a boronic acid group in combination. Here, examples of the vertical alignment agent include those described in paragraphs

[0180] to

[0202] of JP-A-2023-4859, the disclosures of which are incorporated herein by reference.

[0053] [Surfactant] The composition of the present invention may contain a surfactant. There are no particular limitations on the surfactant, and polymeric surfactants and low molecular weight surfactants can be used, and the compounds described in paragraphs

[0253] to

[0293] of JP-A No. 2011-237513 can be used. In addition, fluorine (meth)acrylate polymers described in paragraphs

[0018] to

[0043] of JP-A No. 2007-272185 can also be used as surfactants. Examples of surfactants include compounds described in paragraphs

[0079] to

[0102] of JP-A-2007-069471, polymerizable liquid crystal compounds represented by formula (4) described in JP-A-2013-047204 (particularly compounds described in paragraphs

[0020] to

[0032] ), polymerizable liquid crystal compounds represented by formula (4) described in JP-A-2012-211306 (particularly compounds described in paragraphs

[0022] to

[0029] ), and liquid crystal alignment promoters represented by formula (4) described in JP-A-2002-129162 (particularly compounds described in paragraphs

[0032] to

[0032] ). Other examples that can be used include compounds described in paragraphs

[0076] to

[0078] and paragraphs

[0082] to

[0084] of the present invention, compounds represented by formulas (4), (II), and (III) described in JP-A-2005-099248 (particularly the compounds described in paragraphs

[0092] to

[0096] ), compounds described in paragraphs

[0013] to

[0059] of Japanese Patent No. 4,385,997, compounds described in paragraphs

[0018] to

[0044] of Japanese Patent No. 5,034,200, and compounds described in paragraphs

[0019] to

[0038] of Japanese Patent No. 4,895,088. One surfactant may be used alone, or two or more surfactants may be used in combination.

[0054] [Solvent] From the viewpoint of workability and the like, the composition of the present invention preferably contains a solvent. Examples of the solvent include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, acetylacetone, etc.), ethers (e.g., dioxane, tetrahydrofuran, tetrahydropyran, dioxolane, tetrahydrofurfuryl alcohol, cyclopentyl methyl ether, dibutyl ether, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., benzene, toluene, xylene, tetralin, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, trichloromethane (chloroform), dichloroethane, dichlorobenzene, 1,1,2,2-tetrachloroethane, chlorotoluene, etc.), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, diethyl carbonate, ethyl acetoacetate, n-pentyl acetate, ethyl benzoate, benzyl benzoate, butyl carbitol acetate, diethylene glycol monoethyl ether acetate, Examples of suitable solvents include organic solvents such as ethanol, isopropanol, butanol, cyclohexanol, furfuryl alcohol, 2-ethylhexanol, octanol, benzyl alcohol, ethanolamine, ethylene glycol, propylene glycol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, phenols (e.g., phenol, cresol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, 1,2-dimethoxyethane, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc.), and heterocyclic compounds (e.g., pyridine, 2,6-lutidine, etc.), as well as water. These solvents may be used alone or in combination of two or more.

[0055] [Polymerization initiator] The composition of the present invention may contain a polymerization initiator. There are no particular limitations on the polymerization initiator, but it is preferably a photosensitive compound, i.e., a photopolymerization initiator. As the photopolymerization initiator, various compounds can be used without particular limitations. Examples of photopolymerization initiators include α-carbonyl compounds (U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (U.S. Pat. No. 2,722,512), polynuclear quinone compounds (U.S. Pat. Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazole dimers and p-aminophenyl ketones (U.S. Pat. No. 3,549,367). ), acridine and phenazine compounds (JP 60-105667 A and U.S. Pat. No. 4,239,850 A), oxadiazole compounds (U.S. Pat. No. 4,212,970 A), o-acyloxime compounds (JP 2016-27384 A

[0065] ), and acylphosphine oxide compounds (JP 63-40799 A, JP 5-29234 A, JP 10-95788 A, and JP 10-29997 A). Commercially available photopolymerization initiators can also be used, including Irgacure-184, Irgacure-907, Irgacure-369, Irgacure-651, Irgacure-819, Irgacure-OXE-01, and Irgacure-OXE-02 manufactured by BASF.

[0056] [Electro-optical layer] The electro-optical layer (EO layer) of the present invention is an electro-optical layer formed by fixing the alignment state of the specific liquid crystal compound contained in the composition of the present invention described above.Here, the method for forming the electro-optical layer is not particularly limited, and conventionally known methods can be appropriately adopted.For example, a method including the following steps in this order is preferred: applying the composition of the present invention described above to a substrate (including a temporary support) or an alignment layer provided on the substrate to form a coating film; orienting the specific liquid crystal compound contained in the coating film; and fixing the alignment state of the specific liquid crystal compound.In addition, in the above method, the specific organic dye is aligned along the alignment of the specific liquid crystal compound, and this alignment state is fixed.

[0057] The electro-optical layer of the present invention may be one that has been subjected to a poling treatment or one that has not been subjected to a poling treatment. Here, the poling treatment is not particularly limited, and known poling treatments such as optical poling and electric field poling can be used. Among these, the electric field poling method is particularly preferred in terms of the simplicity of the apparatus and the high degree of orientation that can be obtained.

[0058] In the present invention, because an EO layer exhibits a higher electro-optical constant, the degree of orientation of the specific organic dye contained in the electro-optical layer is preferably 0.3 or more, more preferably 0.3 or more but less than 0.9, and even more preferably 0.6 or more but less than 0.9. Here, the degree of orientation of the specific organic dye refers to the degree of orientation at the absorption maximum of the specific organic dye, calculated using the following method. Specifically, using a UV-Vis-NIR spectrophotometer (V-670, manufactured by JASCO Corporation) and an automatic absolute reflectance measurement unit (ARMN-735, manufactured by JASCO Corporation), absorbance is measured in 10° increments in the polar angle range of 0° to 60° in the in-plane slow axis direction, and the extinction coefficients kx(λ), ky(λ), and kz(λ) of the organic dye are determined from the values ​​by fitting. Next, the absorption anisotropies Ao(λ) and Ae(λ) of the specific organic dye are determined according to the following formulas (A) to (D), and the degree of orientation S is calculated according to the following formula (E). (A) To(λ) = EXP{-4 x π x (kx(λ) + ky(λ)) / 2 x d / λ} (B) Te(λ) = EXP{-4 x π x kz(λ) x d / λ} (C) Ao(λ) = - log(To(λ)) (D) Ae(λ) = - log(Te(λ)) (E) S(λ) = [Ao(λ) / Ae(λ) - 1] / [Ao(λ) / Ae(λ) + 2] Here, d represents the film thickness (nm) of the electro-optical layer, To(λ) and Te(λ) represent the transmittance, and Ao(λ) and Ae(λ) represent the absorbance.

[0059] [Laminate] The laminate of the present invention is a laminate having an alignment layer and the above-described electro-optic layer of the present invention disposed on the alignment layer.

[0060] [Alignment Layer] The alignment layer of the laminate of the present invention may be any layer that can achieve the desired alignment state for the specific liquid crystal compound contained in the composition of the present invention. Methods for forming the alignment layer include, for example, rubbing an organic compound (preferably a polymer) onto the film surface, oblique vapor deposition of an inorganic compound, formation of a layer with microgrooves, and accumulation of an organic compound (e.g., ω-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate, etc.) using the Langmuir-Blodgett method (LB film). Furthermore, alignment layers that exhibit alignment function upon application of an electric field, a magnetic field, or light irradiation are also known. Alternatively, the alignment layer may be formed by a single coating of the composition of the present invention. For example, a composition containing a specific liquid crystal compound, a specific organic dye, and an alignment agent may be applied to a temporary support, and the alignment agent may spontaneously become ubiquitous on the temporary support side before or during evaporation of the solvent from the coating solution, thereby forming an alignment layer. The alignment layer formed in this manner is defined as a portion where the alignment agent component constituting the film per 1 g is 50% by mass or more after the solvent has evaporated.

[0061] The thickness of the alignment layer is not particularly limited, but is preferably 0.01 to 2.0 μm, and more preferably 0.01 to 1.0 μm. The thickness of the alignment layer is calculated as the average value of measurements taken at any five points using a surface roughness meter (for example, P-10 (manufactured by TENCOR Corporation)).

[0062] In the present invention, an alignment layer formed by rubbing treatment (rubbed alignment layer) is preferred from the viewpoint of ease of control of the pretilt angle of the alignment layer, and a photo-alignment layer formed by light irradiation is preferred from the viewpoint of uniformity of alignment.

[0063] Photo-alignment compounds used in the photo-alignment layer formed by light irradiation are described in many documents, etc. In the present invention, for example, azo compounds described in JP-A Nos. 2006-285197, 2007-76839, 2007-138138, 2007-94071, 2007-121721, 2007-140465, 2007-156439, 2007-133184, 2009-109831, Japanese Patent Nos. 3883848 and 4151746, and compounds described in JP-A No. 2002-229039 are used. Preferred examples include aromatic ester compounds of the above, maleimide and / or alkenyl-substituted nadimide compounds having a photo-alignable unit described in JP-A Nos. 2002-265541 and 2002-317013, photo-crosslinkable silane derivatives described in Japanese Patent Nos. 4205195 and 4205198, and photo-crosslinkable polyimides, polyamides, or esters described in Japanese Patent Publication Nos. 2003-520878, 2004-529220, or Japanese Patent No. 4162850. Azo compounds, photo-crosslinkable polyimides, polyamides, or esters are more preferred.

[0064] Among these, it is preferable to use a photosensitive compound having a photo-alignment group that undergoes at least one of dimerization and isomerization under the action of light as the photo-alignment compound.In addition, as the photo-alignment group, for example, a group having a cinnamic acid (cinnamoyl) structure (skeleton), a group having a coumarin structure (skeleton), a group having a chalcone structure (skeleton), a group having a benzophenone structure (skeleton), and a group having an anthracene structure (skeleton) can be mentioned.Among these groups, a group having a cinnamoyl structure and a group having a coumarin structure are preferred, and a group having a cinnamoyl structure is more preferred.

[0065] The photosensitive compound having the photoalignable group may further have a crosslinkable group. The crosslinkable group is preferably a thermally crosslinkable group that undergoes a curing reaction under the action of heat, or a photocrosslinkable group that undergoes a curing reaction under the action of light, and may be a crosslinkable group having both a thermally crosslinkable group and a photocrosslinkable group. Examples of the crosslinkable group include an epoxy group, an oxetanyl group, -NH-CH ２ Examples of the group include at least one selected from the group consisting of a group represented by -O-R (R represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms), a group having an ethylenically unsaturated double bond, and a blocked isocyanate group. Among these, an epoxy group, an oxetanyl group, and a group having an ethylenically unsaturated double bond are preferred. A three-membered cyclic ether group is also called an epoxy group, and a four-membered cyclic ether group is also called an oxetanyl group. Specific examples of the group having an ethylenically unsaturated double bond include a vinyl group, an allyl group, a styryl group, an acryloyl group, and a methacryloyl group, with an acryloyl group or a methacryloyl group being preferred.

[0066] A photo-alignment layer formed from the above materials is irradiated with linearly polarized or non-polarized light to produce a photo-alignment layer. In this specification, "linearly polarized light irradiation" and "non-polarized light irradiation" refer to operations for causing a photoreaction in the photo-alignment material. The wavelength of the light used varies depending on the photo-alignment material used, and is not particularly limited as long as it is the wavelength necessary for the photoreaction. The peak wavelength of the light used for photoirradiation is preferably 200 nm to 700 nm, and ultraviolet light with a peak wavelength of 400 nm or less is more preferred.

[0067] Examples of light sources used for light irradiation include commonly used light sources, such as lamps such as tungsten lamps, halogen lamps, xenon lamps, xenon flash lamps, mercury lamps, mercury xenon lamps, and carbon arc lamps, various lasers (e.g., semiconductor lasers, helium-neon lasers, argon ion lasers, helium-cadmium lasers, and YAG (yttrium aluminum garnet) lasers), light-emitting diodes, and cathode ray tubes.

[0068] As a means for obtaining linearly polarized light, a method using a polarizing plate (e.g., an iodine polarizing plate, a dichroic dye polarizing plate, and a wire grid polarizing plate), a method using a prism element (e.g., a Glan-Thompson prism) or a reflective polarizer utilizing the Brewster angle, or a method using light emitted from a polarized laser light source can be employed. Alternatively, a filter or a wavelength conversion element may be used to selectively irradiate only light of a required wavelength.

[0069] When the light to be irradiated is linearly polarized light, a method is adopted in which the light is irradiated from the top or back surface of the alignment layer perpendicularly or obliquely to the surface of the alignment layer. The incident angle of the light varies depending on the photo-alignment material, but is preferably 0 to 90° (perpendicular), and more preferably 40 to 90°. When the light is non-polarized light, the alignment layer is irradiated with non-polarized light obliquely. The incident angle is preferably 10 to 80°, more preferably 20 to 60°, and even more preferably 30 to 50°. The irradiation time is preferably 1 to 60 minutes, and more preferably 1 to 10 minutes.

[0070] When patterning is required, a method of irradiating light using a photomask the number of times required to form a pattern, or a method of writing a pattern by laser light scanning can be used.

[0071] [Transfer film] The transfer film of the present invention is a transfer film having a temporary support, an alignment layer, and the electro-optical layer of the present invention in this order, and is preferably a transfer film for producing an optical waveguide. Note that the alignment layer of the transfer film of the present invention can be the same as the alignment layer described in the laminate of the present invention.

[0072] [Temporary Support] The temporary support of the transfer film of the present invention is a member that supports the alignment layer or the electro-optical layer, and can be removed after the optical waveguide is produced, for example.

[0073] The temporary support may have either a single-layer structure or a multilayer structure. As the temporary support, a film is preferred, and a polymer film is more preferred. Furthermore, as the temporary support, a polymer film that is flexible and does not significantly deform, shrink, or stretch under pressure or under pressure and heat is also preferred, and a polymer film that is free from deformation such as wrinkles and scratches is also preferred. Examples of such polymer films include polymer films containing at least one selected from the group consisting of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and triacetyl cellulose (TAC), and a polyethylene terephthalate film is preferred.

[0074] The thickness of the temporary support is not particularly limited, but from the viewpoint of ease of handling and versatility, it is preferably 5 to 200 μm, more preferably 5 to 150 μm, and even more preferably 5 to 100 μm. Here, the thickness of the temporary support is calculated as the average value when 100 points are measured at 1 cm intervals over an area of ​​10 cm × 10 cm using a pencil-type high-precision digital length measuring instrument PHA-13W manufactured by Tosei Engineering Co., Ltd., with an E-ST-100DB stand attached, and a MINICOM-M (Model E-M) as a display device.

[0075] [Optical Waveguide] The optical waveguide of the present invention has a core layer and a clad layer, and the core layer is the electro-optical layer of the present invention described above. Here, the core layer of the optical waveguide of the present invention can be any of the core layers used in conventionally known optical waveguides. The optical waveguide of the present invention may be of any type, including an inverted ridge type, a ridge type, and a channel type. However, a preferred embodiment includes, for example, a substrate, a lower clad layer formed on the substrate, a core layer (the electro-optical layer of the present invention) formed on a portion of the upper surface of the lower clad layer, and an upper clad layer formed on the lower clad layer so as to embed the core layer. In the present invention, it is preferable to use the electro-optical layer of the present invention as the core layer of the inverted ridge optical waveguide described in paragraphs

[0051] to

[0056] and FIG. 4 of WO 2017 / 159815. Furthermore, when the electro-optical layer of the present invention is used as a core layer, an optical waveguide can be produced, for example, by laminating the electro-optical layer of the transfer film of the present invention described above to a lower clad layer, peeling off the temporary support, and then providing an upper clad layer.

[0076] [Optical Modulator] The optical modulator of the present invention is an optical modulator having the optical waveguide of the present invention described above. Furthermore, as long as the optical modulator of the present invention has the optical waveguide of the present invention as a phase modulation section, other configurations such as electrodes are not particularly limited, and configurations of conventionally known optical modulators can be appropriately adopted.

[0077] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0078] [Example 1] [Formation of Alignment Layer] The following alignment layer composition 1 was applied by spin coating onto a glass substrate on which ITO had been sputtered, and dried at 100°C for 1 minute to form an alignment layer with a thickness of 0.6 µm.

[0079] ------------------------------------------------------------------ Alignment layer forming composition 1 -------------------------------------------------- Polyvinyl alcohol (Poval 3-88; manufactured by Kuraray) 2.1 parts by mass Methanol 44.4 parts by mass Distilled water 53.5 parts by mass ------------------------------------------------------------------

[0080] [Formation of electro-optical layer] The following composition for forming an electro-optical layer was applied to the alignment layer by spin coating and aged for 30 seconds at 130° C. to form an electro-optical layer (thickness 1.6 μm) in which the liquid crystal compound L1 and the organic dye E1 were vertically aligned. In this way, a laminate was produced in which the glass substrate, the alignment layer, and the electro-optical layer were arranged in this order.

[0081] ---------------------------------------------------------------- Composition for forming electro-optical layer ---------------------------------------------------------------- Liquid crystal compound L1 (77.5 parts by mass) below; Organic dye E1 (22.5 parts by mass) below; Cyclopentanone (669.2 parts by mass) ----------------------------------------------------------------

[0082] The resulting laminate was placed on a hot plate and subjected to corona poling treatment. Specifically, the laminate was held at 150°C for 10 minutes with a charging voltage of 6 kV applied at a distance of 10 mm from the electro-optical layer, and then air-cooled to 30°C while the charging voltage was still applied, after which the charging voltage was removed.

[0083] Examples 2 to 13 Laminates before and after corona poling treatment were prepared in the same manner as in Example 1, except that the types and blending amounts (parts by mass) of the liquid crystal compound, organic dye, alignment agent, and surfactant were changed to those shown in Table 1 below.

[0084] [Evaluation] (1) Various physical properties The presence or absence of ferroelectricity, Σ(xi × μi) and liquid crystal phase of the liquid crystal compound, as well as the second-order molecular susceptibility, aspect ratio and θeg (the angle between the vector of the molecular long axis and the vector of the transition dipole moment) of the organic dye were measured or calculated by the methods described above. These results are shown in Table 1 below.

[0085] (2) Degree of Orientation of Organic Dye The degree of orientation of the organic dye in the electro-optical layer of the laminate before corona poling was calculated by the method described above and evaluated according to the following criteria. The results are shown in Table 1 below. <Evaluation Criteria> A: 0.6 or more, less than 0.9 B: 0.3 or more, less than 0.6 C: -0.5 or more, less than 0.3

[0086] (3) Dye Deposition of Organic Dye The solubility of the organic dye in the electro-optical layer of the laminate before corona poling treatment was evaluated by the following procedure. The laminate was placed on the sample stage of an optical microscope (e.g., MX36 manufactured by Olympus Corporation) and observed at three random locations to confirm the presence or absence of organic dye crystals of 5 μm or more in size. If no organic dye crystals were present, the organic dye was considered to be dissolved (no dye deposition). The presence or absence of organic dye crystals is shown in Table 1 below.

[0087] (4) Electro-optic Constants The electro-optic constants (hereinafter also referred to as "r values") were calculated by measuring the applied voltage dependence of the refractive index change at a wavelength of 1309 nm using a prism coupler device (MODEL 2010 / M, manufactured by Metricon) and a coated prism (P-200C, a prism with a nickel-coated prism surface) for the prepared corona poling-treated laminate. Based on the r value, the electro-optic constant values ​​were evaluated according to the following criteria. The results are shown in Table 1 below. The r value was calculated using the following formula (R): In formula (R), δn / δV is the slope of the applied voltage dependence of the refractive index change, d is the thickness (pm) of the laminate, and nTM is the refractive index of the laminate (laminate after corona poling) with no voltage applied when a TM wave is incident. r = {(δn / δV) × 2 × d} / (nTM3) Formula (R) <Evaluation criteria> A: 80 pm / V or more, less than 100 pm / V B: 50 pm / V or more, less than 80 pm / V C: 30 pm / V or more, less than 50 pm / V D: 10 pm / V or more, less than 30 pm / V E: 0 pm / V or more, less than 10 pm / V

[0088]

[0089] The structures of the liquid crystal compounds L1 to L8, the organic dyes E1 to E5, the alignment agent F1 and the surfactant S1 in Table 1 above are shown below.

[0090] Liquid crystal compound L1 (weight average molecular weight: 40000)

[0091] Liquid crystal compound L2 (weight average molecular weight: 15000)

[0092] Liquid crystal compound L3

[0093] Liquid crystal compound L4 (weight average molecular weight: 14000)

[0094] Liquid crystal compound L5

[0095] liquid crystal compound L6

[0096] liquid crystal compound L7

[0097] liquid crystal compound L8

[0098] Organic dye E1

[0099] organic dye E2

[0100] organic dye E3

[0101] organic dye E4

[0102] organic dye E5

[0103] Orientation agent F1

[0104] Surfactant S1 (weight average molecular weight: 16,000; the numerical value for each repeating unit indicates the content (mass %) of each repeating unit relative to the total repeating units.)

[0105] From the results shown in Table 1 above, the second-order molecular susceptibility is 15000×10 －３３ It was found that when an organic dye having a molecular weight less than esu was blended, the electro-optical constant of the electro-optical layer formed was low (Comparative Example 1). It was also found that when a liquid crystal compound exhibiting ferroelectricity was blended, the electro-optical constant of the electro-optical layer formed was low (Comparative Example 2). It was also found that when the low-molecular-weight liquid crystal compound and the high-molecular-weight liquid crystal compound did not satisfy the above condition (1), the electro-optical constant of the electro-optical layer formed was low (Comparative Examples 3 and 4).

[0106] Second-order molecular susceptibility is 15,000 x 10 －３３esu or more is blended and the low molecular weight liquid crystal compound and the high molecular weight liquid crystal compound satisfy the above condition (1), the electro-optical constant of the formed electro-optical layer is found to be high (Examples 1 to 13). In particular, a comparison of Examples 1, 6, 9, 11, and 13 shows that the electro-optical constant of the formed electro-optical layer is higher when the low molecular weight liquid crystal compound and the high molecular weight liquid crystal compound satisfy the above condition (2). Furthermore, a comparison of Example 2 and Example 8 shows that the content of the low molecular weight liquid crystal compound or the content of the repeating unit L (W Ｌ ) and the content of specific organic dyes (W Ｅ ) and the mass ratio (W Ｅ / W Ｌ ) is 0.6 or less, the electro-optical constant of the electro-optical layer formed is higher. Furthermore, a comparison between Examples 1, 4, and 5 shows that the electro-optical constant of the electro-optical layer formed is higher when the aspect ratio of the organic dye is 2.0 or more. Furthermore, a comparison between Example 1 and Example 3 shows that the electro-optical constant of the electro-optical layer formed is higher when the angle θeg between the vector of the molecular long axis and the vector of the transition dipole moment in the organic dye is 10.0° or less.

[0107] [Example 13] [Formation of thermoplastic resin layer] A coating liquid for a thermoplastic resin layer having the following composition was applied using a slot die onto a temporary support made of a polyethylene terephthalate film (width: 1610 mm, thickness: 75 μm), and dried at 100°C for 3 minutes to form a thermoplastic resin layer having a thickness of 5 μm. -------------------------------------------------- Coating liquid for thermoplastic resin layer -------------------------------------------------- Binder A (listed below) 8.47 parts by mass 1-Methoxy-2-propyl acetate 3.47 parts by mass Binder B (listed below) 24.6 parts by mass Plasticizer: 2,2-bis[4-(methacryloxypolyethoxy)phenyl]propane (manufactured by Shin-Nakamura Kogyo Co., Ltd.) 5.40 parts by mass Surfactant 1: Megafac F-780-F (manufactured by Dainippon Ink and Chemicals, Inc.) 0.83 parts by weight Methyl ethyl ketone 42.6 parts by mass Methanol 13.5 parts by mass --------------------------------------------------

[0108] <Binder A> Aromatex FM601 (manufactured by Mitsui Chemicals, Inc., weight average molecular weight = 90,000, solid content concentration 21 mass%, methyl methacrylate / 2-ethylhexyl acrylate / benzyl methacrylate / methacrylic acid copolymer ((molar ratio = 55 / 11.7 / 4.5 / 28.2): 21 parts, methyl ethyl ketone: 26 parts, 1-methoxy-2-propyl acetate: 13 parts, methanol: 40 parts)

[0109] <Binder B> Arosset 7055 (manufactured by Nippon Shokubai Co., Ltd., weight average molecular weight = 8000, solid content concentration 41 mass%, styrene / acrylic acid copolymer (molar ratio 63 / 37): 41 parts, methyl ethyl ketone: 50 parts, 1-methoxy-2-propyl acetate: 9 parts)

[0110] [Formation of Orientation Layer] An orientation layer having a thickness of 0.6 μm was formed on the thermoplastic resin layer in the same manner as in Example 1.

[0111] [Formation of Electro-Optical Layer] An electro-optical layer (thickness: 1.6 μm) was formed on the alignment layer in the same manner as in Example 1.

[0112] [Formation of Protective Layer] A polypropylene protective layer (thickness: 12 μm, surface roughness: 15 nm) was pressure-bonded to the formed electro-optical layer to prepare a transfer film (layer structure: temporary support / thermoplastic resin layer / alignment layer / electro-optical layer / protective layer).

[0113] [Example 14] [Fabrication of Optical Waveguide and Optical Modulator] A clad material composition prepared by the method described below was used to form the clad, and the electro-optical layer-forming composition used in Example 1 was used to form the core, and a ridge-type optical waveguide modulator was manufactured by the following procedure.

[0114] <Cladding material composition> 2.3 g of 3-methacryloyloxypropyltrimethoxysilane (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.23 g of zirconium propoxide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.02 g of benzoyl peroxide (manufactured by Kanto Chemical Co., Ltd.) were added to a mixed solution of 1.3 g of ethanol and 0.17 g of 0.1 N aqueous hydrochloric acid solution and stirred. This mixture was stored at 10°C or below for 24 hours or more to obtain a cladding material composition.

[0115] <Preparation of Lower Electrode> A lower electrode was prepared by vacuum-depositing metals on a substrate (silicon wafer) in the following order: chromium (50 nm), aluminum (400 to 500 nm), and chromium (50 nm).

[0116] <Preparation of Lower Cladding> The cladding material composition prepared above was spin-coated (2,000 rpm x 60 seconds) onto the lower electrode prepared above, and heated on a hot plate at 140°C for 30 minutes to prepare a lower cladding. The film thickness of the prepared lower cladding was 2 to 2.5 μm. A photoresist (MICROPOSIT S1813G, manufactured by Rohm and Haas Electronic Materials Co., Ltd.) was applied to a thickness of approximately 2 μm onto the prepared lower cladding, and heated at 90°C for 3 minutes. The resulting photoresist was exposed (high-pressure mercury lamp) through a mask having a linear waveguide pattern with a width of 5 μm and a length of 20 mm, and developed with a developer (MICROPOSIT M319, manufactured by Rohm and Haas Electronic Materials Co., Ltd.). Using this resist pattern as a mask, SF was applied using an ICP dry etching system. ６ Etching was performed using a reactive gas to form an inverted ridge pattern in the lower cladding. The etching was performed so that the ridge height was 800 to 900 nm. The photoresist was then removed to obtain a lower cladding with an inverted ridge pattern.

[0117] <Preparation of Core> The composition for forming an electro-optical layer used in Example 1 was used as the core material and spin-coated (600 rpm x 10 seconds) onto the upper part of the lower cladding on which the above-mentioned inverted ridge pattern had been formed. This was dried on a hot plate at 130°C for 30 minutes and then at 25°C for 4 hours under vacuum to prepare a core. The film thickness of the prepared core was 1.5 μm.

[0118] <Preparation of Upper Clad> A cured film (2.5 μm) was prepared on the core prepared above as an upper clad using the same material as that used for the lower clad, in the same manner as for preparing the lower clad, except that the heating conditions were changed to 120° C. and 1 hour.

[0119] <Fabrication of Upper Electrode> Aluminum (100 nm) was vacuum-deposited on the upper cladding fabricated above to fabricate an upper electrode. Finally, both end faces of the waveguide were cut by substrate cleavage to form light-incident end faces, completing the optical waveguide modulator (optical waveguide).

Claims

1. A liquid crystal compound that does not exhibit ferroelectricity and has a second-order molecular susceptibility of 15,000 x 10 －３３ esu or higher organic dye, wherein the liquid crystal compound exhibits nematic liquid crystallinity or smectic liquid crystallinity, and the liquid crystal compound is at least one of a low molecular weight liquid crystal compound and a polymer liquid crystal compound having a repeating unit L exhibiting liquid crystallinity, and the low molecular weight liquid crystal compound and the polymer liquid crystal compound satisfy the following condition (1): Σ(xi×μi)≧5 (1) where, in formula (1), xi represents the molar fraction of the low molecular weight liquid crystal compound and the repeating unit L of the i-th component among the low molecular weight liquid crystal compound and the repeating unit L of the polymer liquid crystal compound contained in the electro-optical composition, and μi represents the dipole moment of the low molecular weight liquid crystal compound and the repeating unit L of the i-th component.

2. The electro-optical composition according to claim 1, wherein the low-molecular-weight liquid crystal compound and the polymeric liquid crystal compound satisfy the following condition (2): Σ(xi×μi)≧7 (2) where, in formula (2), xi represents the molar fraction of the low-molecular-weight liquid crystal compound and the repeating unit L of the i-th component among the repeating units L contained in the low-molecular-weight liquid crystal compound and the polymeric liquid crystal compound contained in the electro-optical composition, and μi represents the dipole moment of the low-molecular-weight liquid crystal compound and the repeating unit L of the i-th component.

3. The electro-optical composition according to claim 1, wherein the content of the organic dye relative to the content of the low molecular weight liquid crystal compound and the content of the repeating unit L possessed by the high molecular weight liquid crystal compound is 0.6 or less in mass ratio.

4. The electro-optical composition according to claim 1, wherein the monomer forming the repeating unit L of the low molecular weight liquid crystal compound or the polymer liquid crystal compound is a compound represented by the following formula (3): E1-(L1-M)n-L2-E2 (3) In the formula (3), n represents an integer of 2 or more, and M represents an aromatic ring which may have a substituent. Multiple M's may be the same or different. L1 and L2 each independently represent a single bond or a divalent linking group. Multiple L1's may be the same or different. E1 and E2 each independently represent a hydrogen atom, an electron-withdrawing group, or a polymerizable group. However, with respect to the monomer, at least one of E1 and E2 represents a polymerizable group. At least one of E1 and E2 and the substituents that M may have represents an electron-withdrawing group.

5. The electro-optical composition according to claim 4, wherein the electron-withdrawing group represented by E1 and E2 in formula (3) and at least one of the substituents that M may have is a group represented by any of the following formulas (EA-1) to (EA-33): In the formulae (EA-1) to (EA-33), * represents a bonding position. R represents a hydrogen atom or a substituent. na represents an integer of 0 to 5, and when na represents an integer of 2 to 5, the multiple Rs may be the same or different. X represents -C(R Ｅ１１ ) (R Ｅ１２ )-, -C(=O)-, -C(=S)-, or -C(=NR Ｅ１３ )-. Ｅ１１ and R Ｅ１２ each independently represents a hydrogen atom, a halogen atom, an alkyl group, a fluoroalkyl group, an aryl group, a cyano group, or a nitro group, and —CH ２ - may be substituted with a divalent linking group, and the hydrogen atoms of the alkyl group and aryl group may be substituted with a substituent. Ｅ１３ represents a hydrogen atom or an alkyl group, and —CH ２ - may be substituted with a divalent linking group. Y is -O-, -S-, -N(R Ｅ１４ )- or -S(=O)-. Ｅ１４ represents a hydrogen atom, or an alkyl group, aryl group, alkylcarbonyl group, arylcarbonyl group, alkylsulfonyl group, or arylsulfonyl group, each of which may have a substituent. Z represents -C(H)= or -N=.

6. The electro-optical composition according to claim 1, wherein the content of said organic dye is 5 mass % or more based on the total mass of the solid content of said electro-optical composition.

7. The electro-optical composition according to claim 1, wherein the organic dye has a molecular aspect ratio of 2.0 or more.

8. The electro-optical composition according to claim 1, wherein the angle θeg formed between the vector of the molecular long axis and the vector of the transition dipole moment in said organic dye is 10.0° or less.

9. An electro-optical layer obtained by fixing the alignment state of a liquid crystal compound contained in the electro-optical composition according to any one of claims 1 to 8.

10. The electro-optical layer according to claim 9, wherein the organic dye contained in said electro-optical layer has a degree of orientation of 0.3 or more.

11. A stack comprising an alignment layer and an electro-optic layer according to claim 9 disposed on said alignment layer.

12. A transfer film comprising, in this order, a temporary support, an alignment layer, and the electro-optical layer according to claim 9.

13. An optical waveguide having a core layer and a clad layer, wherein the core layer is the electro-optic layer according to claim 9.

14. An optical modulator comprising the optical waveguide according to claim 13.

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