WO2020004303A1 - Polarizer and image display device - Google Patents

Abstract

The present invention addresses the problem of providing a polarizer having a high degree of orientation, and an image display device using the polarizer. The problem is solved by a polarizer formed from a polarizer-forming composition containing a liquid crystalline compound and a dichroic material, wherein the liquid crystalline compound and the dichroic material are horizontally oriented, aggregates are observed on a surface observed by a scanning electron microscope, and when the length of the long axis of the aggregates is L and the length of the short axis thereof is D, the number of needle-shaped aggregates satisfying L ≥ 300 nm and L/D > 2 is 15 or more per 40 μm², and the number of needle-shaped aggregates satisfying L ≤ 500 nm is 80% or more.

Description

Polarizer and image display device

The present invention relates to a polarizer and an image display device.

Conventionally, when an attenuating function, a polarizing function, a scattering function, or a light shielding function of irradiation light including laser light or natural light is required, a device that operates according to a different principle for each function is used. Was. Therefore, products corresponding to the above functions are also manufactured by different manufacturing processes for each function.
For example, in an image display device (for example, a liquid crystal display device), a linear polarizer or a circular polarizer is used to control optical rotation or birefringence in display. In addition, in an organic light emitting diode (Organic Light Emitting Diode: OLED), a circular polarizer is used to prevent reflection of external light.

Conventionally, iodine has been widely used as a dichroic substance in these polarizers. However, in recent years, a polarizer using an organic dye as a dichroic substance instead of iodine has been studied.
For example, Patent Literature 1 discloses a light absorption anisotropic film containing a polymer liquid crystalline compound and a dichroic substance.

JP 2011-237513 A

な In such a situation, the present inventors prepared a polarizer with reference to the example of Patent Document 1 and evaluated the degree of orientation. As a result, it has been clarified that it is desirable to further improve the degree of orientation in view of the expected performance improvement of the image display device and the like.

Therefore, in view of the above circumstances, an object of the present invention is to provide a polarizer having a high degree of orientation and an image display device having the polarizer.

た め In order to solve this problem, the present invention has the following configuration.

[1] A polarizer formed from a polarizer-forming composition containing a liquid crystal compound and a dichroic substance,
The liquid crystal compound and the dichroic substance are horizontally aligned,
On the surface observed with a scanning electron microscope, an aggregate is observed, and when the length of the long axis of the aggregate is L and the length of the short axis is D,
More than 15 needle-like aggregates, which are aggregates satisfying L ≧ 300 nm and L / D> 2, are observed per 40 μm ² .
A polarizer in which the number of needle-like aggregates satisfying L ≦ 500 nm among the needle-like aggregates is 80% or more.
[2] The polarizer according to [1], wherein 90% or more of the needle-like aggregates form an angle between the alignment axis and the long axis of the liquid crystalline compound of 5 ° or more.
[3] An image display device having the polarizer according to [1] or [2].

As described below, according to the present invention, it is possible to provide a polarizer having a high degree of orientation and an image display device having the polarizer.

FIG. 1 is a diagram conceptually showing the surface of an example of the polarizer of the present invention. FIG. 2 is a diagram of a micrograph of an example of the polarizer of the present invention, which is output after image processing. FIG. 3 is a diagram of a micrograph of a comparative example of the polarizer of the present invention, which is output after image processing. FIG. 4 is a diagram of a micrograph of a comparative example of the polarizer of the present invention, which is output after image processing.

Hereinafter, the present invention will be described in detail.
The description of the components described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In this specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit.
Further, as each component, one kind of a substance corresponding to each component may be used alone, or two or more kinds may be used in combination. Here, when two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified.
In the present specification, “(meth) acrylate” is a notation representing “acrylate” or “methacrylate”, “(meth) acryl” is a notation representing “acryl” or “methacryl”, and “ “(Meth) acryloyl” is a notation representing “acryloyl” or “methacryloyl”.

[Polarizer]
FIG. 1 conceptually shows an image obtained by observing the surface of an example of the polarizer of the present invention with a scanning electron microscope.

The polarizer of the present invention is a polarizer formed from a polarizer-forming composition containing a liquid crystal compound and a dichroic substance,
The liquid crystal compound and the dichroic substance are horizontally aligned,
On the surface observed with a scanning electron microscope, an aggregate is observed, and when the length of the long axis of the aggregate is L and the length of the short axis is D,
L ≧ 300 nm and, the needle-like aggregate is an aggregate satisfying L / D> 2, is, 40 [mu] m ² per (observation field 40 [mu] m ² per) 15 or more, is observed, further,
A polarizer in which the number of needle-like aggregates satisfying L ≦ 500 nm among the needle-like aggregates is 80% or more.
The present invention realizes a polarizer having a high degree of orientation by having such a configuration.

In FIG. 1, the portions shown in white in the figure are aggregates. In the example shown in FIG. 1, as an example, the needle according to the present invention in which the aggregate denoted by the symbol N is such that the major axis length L and the minor axis length D satisfy L ≧ 300 nm and L / D> 2. Agglomerates.
As will be shown later in the examples, even in an image obtained by actually observing the surface of the polarizer of the present invention with a scanning microscope, the aggregates have higher brightness than the other regions.

In the polarizer of the present invention, the observation of the surface with a scanning electron microscope (SEM) is specifically performed as follows.
That is, first, a polarizer is set in a hydrophilic treatment apparatus (for example, HDT-400 manufactured by JEOL Ltd.) and subjected to a hydrophilic treatment for 10 minutes in a GRID mode. Next, the polarizer is set in a vacuum deposition machine (for example, JEE-400 manufactured by JEOL Ltd.), and carbon having a thickness of about 10 nm is deposited on the surface subjected to the hydrophilic treatment.
Thereafter, using the surface on which carbon was deposited as an observation surface, the alignment axis (liquid crystal alignment axis) was set on a scanning electron microscope (for example, SU8030 type FE-SEM manufactured by Hitachi High-Technologies Corporation) from a state where the polarizer was placed on a horizontal plane. The rotation axis is set at an inclination of 30 °, and the surface of the polarizer is observed under the conditions of an electron beam acceleration voltage of 2 kV and secondary electron detection such that the orientation axis is in the lateral direction of the SEM image.
In FIG. 1, the direction of the arrow x is the direction of the alignment axis. The direction of the alignment axis is a direction in which the liquid crystal compound and the dichroic substance are aligned in the major axis direction. In one example of the embodiment of the present invention, when the polarizer is formed on the alignment film, the alignment axis coincides with the alignment direction in the alignment film.

The length L and the length D of the long axis of the aggregate are specifically measured as follows.
First, an image obtained by observing and photographing the surface of the polarizer with the SEM as described above is analyzed, a luminance histogram is created, and luminance having the maximum frequency is extracted. Next, a luminance that is 1.2 times the extracted luminance is set as a threshold. Next, an image in which the luminance is binarized using this threshold value is created, and a portion having an area equal to or more than the area (1963 nm ² ) corresponding to a circle having a diameter of 50 nm in the binarized high luminance region is defined as an aggregate. Extract as
Furthermore, each extracted aggregate is approximated by an ellipse, the length of the major axis of the approximated ellipse is defined as the major axis length L, and the minor axis length of the approximated ellipse is defined by the minor axis length of the aggregate. D. The angle formed by the orientation axis and the long axis of the approximated ellipse is defined as the angle formed by the long axis of the acicular aggregate and the orientation axis.
The measurement of the length L of the long axis and the length D of the short axis of such an aggregate may be performed using known image processing software. As the image processing software, for example, the image processing software “ImageJ” is exemplified.

In the polarizer of the present invention, the length of the major axis of the aggregate is L and the length of the minor axis is D, and the needle-like aggregate that satisfies L ≧ 300 nm and L / D> 2 is 40 μm ^2. The ratio of needle-like aggregates satisfying L ≦ 500 nm among the needle-like aggregates is not less than 80%. In other words, in the polarizer of the present invention, at least 15 needle-like aggregates, which are aggregates satisfying L ≧ 300 nm and L / D> 2, are observed per observation field of 40 μm ² , and among the needle-like aggregates, , L ≦ 500 nm is 80% or more.
Specifically, by performing the image analysis as described above, optionally selected, 13.58Myuemu ² areas that do not overlap with each other, in three places (a total of 40 [mu] m ^2), satisfy L ≧ 300 nm and L / D> 2 Extraction and counting of the needle-like aggregates, which are aggregates, are performed, the sum is calculated, and the ratio (the ratio of the number) of the needle-like aggregates satisfying L ≦ 500 nm among the extracted needle-like aggregates is calculated.
The counting of such needle-like aggregates and the calculation of the ratio of needle-like aggregates satisfying L ≦ 500 nm were arbitrarily selected in a region of 40 μm ² (13.58 μm ² × 3) that does not overlap each other, and 10 places. Perform in.
Then, the number of the needle-like aggregates at the 10 points where the measurement was performed and the average value of the ratio of the needle-like aggregates satisfying L ≦ 500 nm were calculated, and this average value was calculated as 40 μm ² per polarizer. And the ratio of needle-like aggregates satisfying L ≦ 500 nm.
Note that the measurement is actually performed in a region of 13.58 μm ² × 3 = 40.74 μm ² , but in the present invention, the fraction is rounded down and referred to as “per 40 μm ² ” for convenience. I have.

In the following description, L / D, which is the ratio of the major axis length L of the aggregate to the minor axis length D, is also referred to as “aspect ratio”.

The polarizer of the present invention has such a configuration to realize a polarizer having a high degree of orientation.
The reason why the orientation of the polarizer is improved by the presence of the acicular aggregates is not clear, but is presumed as follows.
As shown in FIG. 1, a large number of dot-like (island-like) aggregates, needle-like aggregates, and long aggregates in the present invention are observed on the surface of the polarizer. This aggregate is considered to be one or more of an aggregate of a liquid crystal compound, an aggregate of a dichroic substance, and an aggregate of a liquid crystal compound and a dichroic substance.
Such an aggregate has a high degree of orientation. Therefore, having a sufficient length, and a large number of sufficiently thin needle-like aggregates, the presence, and the number of too long needle-like aggregates is not too large, the orientation degree of the polarizer is improved It seems to do.

If the number of needle-like aggregates per 40 μm ² is less than 15, a polarizer having a sufficient degree of orientation cannot be obtained.
In the polarizer of the present invention, the number of needle-like aggregates per 40 μm ² may be 15 or more, preferably 20 or more, and more preferably 30 or more.
Setting the number of needle-like aggregates per 40 μm ² to 20 or more is preferable in that the degree of orientation of the polarizer can be increased and the light resistance can be improved.

In the polarizer of the present invention, the upper limit of the number of needle-like aggregates per 40 μm ² is not limited. However, the polarizer of the present invention has less needle-like aggregates per 40 μm ² in terms of haze and the like.
In consideration of this point, the number of needle-like aggregates per 40 μm ² is preferably 200 or less, and more preferably 150 or less.

On the other hand, if the length L of the needle-shaped aggregates having a length of 500 nm or less is less than 80%, disadvantages such as the inability to obtain a polarizer having a sufficient degree of orientation and poor light resistance are caused.
The proportion of the needle-shaped aggregate having a length L of 500 nm or less is preferably 85% or more, and more preferably 90% or more.

Further, the aspect ratio of the acicular aggregates may be more than 2, but is preferably 2 to 12, more preferably 2 to 8.5.
By setting the aspect ratio of the acicular aggregates to 2 to 12, the degree of polarization of the polarizer can be increased, and a polarizer having a small haze can be obtained.

The length L of the needle-like aggregate may be 300 nm or more, and preferably 300 to 500 μm.
Setting the length L of the acicular aggregate to 300 to 500 μm is preferable in that the degree of polarization of the polarizer can be increased and a polarizer with a small haze can be obtained.

In the polarizer of the present invention, it is preferable that the needle-like aggregate in which the angle between the orientation axis (the direction of the arrow x in FIG. 1) and the major axis direction is 5 ° or more is 90% or more of the needle-like aggregate. , 92% or more.
The needle-like aggregate in which the angle between the orientation axis and the major axis direction is 5 ° or more is preferable because the degree of orientation of the polarizer can be increased when the needle-like aggregate is 90% or more of the needle-like aggregate.
The major axis direction of the needle-shaped aggregate is set to the direction of the major axis of the ellipse set when the aspect ratio of the aggregate is determined as described above.

The ratio of the needle-shaped agglomerates angle between the orientation axis and the long axis direction is 5 ° or more even, as well as the number of needle-like aggregates, such as, arbitrarily selected, the region of 13.58Myuemu ² do not overlap each other The calculation may be performed at three places (a total of 40 μm ² ).
In this regard, the area ratio of the needle-like aggregates described later, the number of aggregates having a large length D in the minor axis direction, the number of aggregates having a long length L, and the area ratio of the aggregates are the same. It is.

In the polarizer of the present invention, the angle between the orientation axis and the major axis direction of the acicular aggregate is preferably 10 ° or less.
Specifically, the ratio of the needle-like aggregates in which the angle between the orientation axis and the major axis direction is 10 ° or less is preferably 15% or more, and more preferably 20% or more.
The longitudinal direction is preferable in that the degree of orientation of the polarizer can be increased by setting the number of needle-like aggregates whose angle in the major axis direction to the orientation axis is 10 ° or less to 15% or more.

In the polarizer of the present invention, the area ratio of the acicular aggregates is preferably from 0.9 to 7.3%, more preferably from 1.0 to 7.0%.
By setting the area ratio of the acicular aggregates to 0.9 to 7.3%, the degree of orientation of the polarizer can be increased, and a polarizer having a low haze can be obtained.

In the polarizer of the present invention, it is preferable that the acicular aggregate has a certain distance in the minor axis direction.
Specifically, the distance between the needle-shaped aggregate and the needle-shaped aggregate closest to the shortest axis direction of the needle-shaped aggregate is preferably 100 nm or more, and more preferably 200 nm or more. By setting the distance in the direction perpendicular to the orientation direction of the adjacent needle-like aggregates to 100 nm or more, it is preferable in that a polarizer with low haze can be obtained.

In addition, such an acicular aggregate is similarly observed on both surfaces of the polarizer of the present invention. The polarizer of the present invention is usually a laminate described below. Therefore, in the polarizer of the present invention, acicular aggregates are similarly confirmed on the surface of the polarizer (the surface on the interface side with the barrier layer) and the interface on the interface side between the polarizer and the alignment film.
Further, such an acicular aggregate is similarly observed in a cross section in a direction orthogonal to the main surface of the polarizer of the present invention. The main surface is the largest surface of a sheet (film, plate).

The polarizer of the present invention is not limited to the needle-shaped aggregate, and the ratio of the aggregate having a length D of 400 nm or more in the minor axis direction is preferably 40% or less, and more preferably 30% or less of the total aggregate. Is more preferred.
By setting the proportion of the aggregate having a length D in the short axis direction of 400 nm or more to 40% or less, it is preferable in that a polarizer with low haze can be obtained.

Further, the polarizer of the present invention is not limited to the needle-shaped aggregate, and the area ratio of the aggregate is preferably 5 to 35%, more preferably 10 to 30%.
Setting the area ratio of the aggregates to 5 to 35% is preferable in that a polarizer having a low haze can be obtained.

Such a polarizer of the present invention can be formed using the following polarizer-forming composition.

(Polarizer forming composition)
The composition for forming a polarizer used in the polarizer of the present invention contains a liquid crystal compound and a dichroic substance. In the following description, the polarizer-forming composition used for the polarizer of the present invention is also referred to as “the present composition”.
In addition, this composition may contain components, such as a polymerization initiator, a solvent, and an interface improver, other than a liquid crystal compound and a dichroic substance.
Hereinafter, each component will be described.

<Liquid crystal compound>
As described above, the present composition has a liquid crystal compound. As the liquid crystal compound, either a low-molecular liquid crystal compound or a high-molecular liquid crystal compound can be used. Here, the “low-molecular liquid crystal compound” refers to a liquid crystal compound having no repeating unit in the chemical structure. In addition, a polymer liquid crystal compound refers to a liquid crystal compound having a repeating unit in a chemical structure. Examples of the low-molecular liquid crystal compound include compounds described in JP-A-2013-228706. Further, examples of the polymer liquid crystalline compound include compounds described in JP-A-2011-237513. The liquid crystal compound is a thermotropic liquid crystal and may show any of a nematic phase and a smectic phase, but preferably shows at least a nematic phase. The temperature range showing the nematic phase is preferably from room temperature (23 ° C.) to 450 ° C., and is preferably from 50 ° C. to 400 ° C. from the viewpoint of handling and production suitability.
In addition, examples of the polymer liquid crystal compound include the following thermotropic liquid crystals and a polymer liquid crystal compound that is a crystalline polymer. In the following description, the thermotropic liquid crystal and the crystalline polymer are also referred to as “specific compounds”.

(Thermotropic liquid crystal)
A thermotropic liquid crystal is a liquid crystal that exhibits a transition to a liquid crystal phase due to a change in temperature.
The specific compound is a thermotropic liquid crystal and may show any of a nematic phase and a smectic phase. However, the specific compound preferably exhibits at least a nematic phase because the degree of orientation of the polarizer is higher and haze is more difficult to be observed (haze is better). In the following description, "the degree of orientation of the polarizer is higher and haze is more difficult to be observed" is also referred to as "the effect of the present invention is more excellent".

(Crystalline polymer)
A crystalline polymer is a polymer that exhibits a transition to a crystal layer due to a change in temperature. The crystalline polymer may exhibit a glass transition in addition to the transition to the crystal layer.
The specific compound is a polymer liquid crystalline compound having a transition from a crystalline phase to a liquid crystal phase when heated (there may be a glass transition in the middle) or a liquid crystalline state due to heating because the effect of the present invention is more excellent. It is preferable that the compound be a high-molecular liquid crystalline compound having a transition to a crystal phase (there may be a glass transition in the middle) when the temperature is lowered after the above.

The presence or absence of crystallinity of the high-molecular liquid crystalline compound is evaluated as follows.
Two polarizers of an optical microscope (ECLIPSE E600 POL manufactured by Nikon) are arranged so as to be orthogonal to each other, and a sample table is set between the two polarizers. Then, a small amount of the high-molecular liquid crystal compound is placed on a slide glass, and the slide glass is set on a hot stage placed on a sample table. While observing the state of the sample, the temperature of the hot stage is raised to a temperature at which the polymer liquid crystal compound exhibits liquid crystallinity, and the polymer liquid crystal compound is brought into a liquid crystal state. After the high-molecular liquid crystalline compound is in a liquid crystal state, the behavior of the liquid crystal phase transition is observed while gradually lowering the temperature of the hot stage, and the temperature of the liquid crystal phase transition is recorded. When the polymer liquid crystalline compound shows a plurality of liquid crystal phases (for example, a nematic phase and a smectic phase), all the transition temperatures are also recorded.
Next, about 5 mg of a sample of the polymer liquid crystalline compound is put in an aluminum pan, covered, and set on a differential scanning calorimeter (DSC) (an empty aluminum pan is used as a reference). The polymer liquid crystal compound measured above was heated to a temperature at which the compound exhibited a liquid crystal phase, and then the temperature was maintained for 1 minute. Thereafter, the calorific value is measured while lowering the temperature at a rate of 10 ° C./min. An exothermic peak is confirmed from the obtained calorific value spectrum.
As a result, when an exothermic peak is observed at a temperature other than the liquid crystal phase transition temperature, the exothermic peak is a peak due to crystallization, and it can be said that the polymer liquid crystalline compound has crystallinity.
On the other hand, when no exothermic peak is observed at a temperature other than the liquid crystal phase transition temperature, it can be said that the polymer liquid crystal compound does not have crystallinity.

The method for obtaining the crystalline polymer is not particularly limited, but as a specific example, a method using a high-molecular liquid crystalline compound containing a repeating unit (1) described below is preferable. A method using a preferred embodiment among the polymer liquid crystalline compounds is more preferable.

(Crystallization temperature)
As described above, the specific compound is a crystallized polymer.
The crystallization temperature of the specific compound is preferably from 0 ° C. to less than 150 ° C., more preferably 120 ° C. or less, still more preferably 15 ° C. to less than 120 ° C., particularly preferably 95 ° C., because the effect of the present invention is more excellent. The following are particularly preferred. The crystallization temperature of the polymer liquid crystalline compound is preferably less than 150 ° C. from the viewpoint of reducing haze.
The crystallization temperature is a temperature of an exothermic peak due to crystallization in DSC described above.

(Preferred embodiment)
The specific compound is preferably a liquid crystalline polymer compound containing a repeating unit represented by the following formula (1), because the effect of the present invention is more excellent. In the following description, the repeating unit represented by the following formula (1) is also referred to as “repeating unit (1)”.

In the above formula (1), P1 represents a main chain of a repeating unit, L1 represents a single bond or a divalent linking group, SP1 represents a spacer group, M1 represents a mesogen group, and T1 represents a terminal group. .

The main chain of the repeating unit represented by P1 specifically includes, for example, groups represented by the following formulas (P1-A) to (P1-D). From the viewpoint of versatility and easy handling, a group represented by the following formula (P1-A) is preferable.

In the formulas (P1-A) to (P1-D), “*” represents a bonding position to L1 in the formula (1). In the formula (P1-A), R ¹ represents a hydrogen atom or a methyl group. In the formula (P1-D), R ² represents an alkyl group.
The group represented by the formula (P1-A) is a unit of the partial structure of the poly (meth) acrylate obtained by polymerization of the (meth) acrylate because the effect of the present invention is more excellent. Is preferred.
The group represented by the formula (P1-B) is preferably an ethylene glycol unit in polyethylene glycol obtained by polymerizing ethylene glycol, because the effect of the present invention is more excellent.
The group represented by the formula (P1-C) is preferably a propylene glycol unit obtained by polymerizing propylene glycol, because the effect of the present invention is more excellent.
The group represented by the formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by polycondensation of silanol, because the effect of the present invention is more excellent.

L1 is a single bond or a divalent linking group.
Examples of the divalent linking group represented by L1 include —C (O) O—, —OC (O) —, —O—, —S—, —C (O) NR ³ —, and —NR ³ C (O) —, —SO ₂ —, and —NR ³ R ⁴ —. In the formula, R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent (for example, a substituent W described below).
When P1 is a group represented by the formula (P1-A), L1 is preferably a group represented by —C (O) O— because the effect of the present invention is more excellent.
When P1 is a group represented by any one of formulas (P1-B) to (P1-D), L1 is preferably a single bond because the effect of the present invention is more excellent.

The spacer group represented by SP1 is selected from the group consisting of an oxyethylene structure, an oxypropylene structure, a polysiloxane structure, and an alkylene fluoride structure because of easy development of liquid crystallinity and availability of raw materials. Preferably, it contains at least one structure.
Here, the oxyethylene structure represented by SP1 is preferably a group represented by *-(CH ₂ -CH ₂ O) _n1- *. In the formula, n1 represents an integer of 1 to 20, and * represents a bonding position to L1 or M1 in the above formula (1). n1 is preferably an integer of 2 to 10, more preferably an integer of 2 to 4, and most preferably 3, because the effect of the present invention is more excellent.
The oxypropylene structure represented by SP1 is preferably a group represented by *-(CH (CH ₃ ) —CH ₂ O) _n2- * because the effect of the present invention is more excellent. In the formula, n2 represents an integer of 1 to 3, and * represents a bonding position to L1 or M1.
Further, the polysiloxane structure represented by SP1 is preferably a group represented by *-(Si (CH ₃ ) ₂ -O) _n3- * because the effect of the present invention is more excellent. In the formula, n3 represents an integer of 6 to 10, and * represents a bonding position to L1 or M1.
Further, the alkylene fluoride structure represented by SP1 is preferably a group represented by *-(CF ₂ -CF ₂ ) _n4- * because the effect of the present invention is more excellent. In the formula, n4 represents an integer of 6 to 10, and * represents a bonding position to L1 or M1.

The mesogen group represented by M1 is a group indicating a main skeleton of a liquid crystal molecule that contributes to liquid crystal formation. Liquid crystal molecules exhibit liquid crystallinity, which is an intermediate state (mesophase) between a crystalline state and an isotropic liquid state. There is no particular limitation on the mesogen group. For example, "FlussigeKristallle in Tabellen II" (VEB Deutsche Verlag fur Grundstoff Industrie, Leipzig, ed., Ed., Pp. 7-16) Reference can be made to the liquid crystal handbook (Maruzen, 2000), especially the description in Chapter 3.
As the mesogen group, for example, a group having at least one cyclic structure selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group, and an alicyclic group is preferable.
The mesogen group preferably has an aromatic hydrocarbon group, more preferably has 2 to 4 aromatic hydrocarbon groups, and more preferably has 3 aromatic hydrocarbon groups, because the effect of the present invention is more excellent. It is more preferred to have

As the mesogen group, the following formula (M1-A) or the following formula (M1-A) from the viewpoint of the development of liquid crystallinity, the adjustment of the liquid crystal phase transition temperature, the availability of raw materials and the suitability for synthesis, and the viewpoint that the effects of the present invention are more excellent. A group represented by M1-B) is preferable, and a group represented by formula (M1-B) is more preferable.

In the formula (M1-A), A1 is a divalent group selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group, and an alicyclic group. These groups may be substituted with a substituent such as an alkyl group, a fluorinated alkyl group, an alkoxy group, or a substituent W described below.
The divalent group represented by A1 is preferably a 4- to 6-membered ring. Further, the divalent group represented by A1 may be a single ring or a condensed ring.
* Represents a binding position to SP1 or T1.

Examples of the divalent aromatic hydrocarbon group represented by A1 include a phenylene group, a naphthylene group, a fluorene-diyl group, an anthracene-diyl group, a tetracene-diyl group, and the like. In light of the availability of the compound, a phenylene group or a naphthylene group is preferable, and a phenylene group is more preferable.

The divalent heterocyclic group represented by A1 may be either aromatic or non-aromatic, but is preferably a divalent aromatic heterocyclic group from the viewpoint of further improving the degree of orientation. .
The atoms other than carbon constituting the divalent aromatic heterocyclic group include a nitrogen atom, a sulfur atom and an oxygen atom. When the aromatic heterocyclic group has a plurality of atoms constituting a ring other than carbon, these may be the same or different.
Specific examples of the divalent aromatic heterocyclic group include, for example, a pyridylene group (pyridine-diyl group), a pyridazine-diyl group, an imidazole-diyl group, a thienylene (thiophene-diyl group), a quinolylene group (quinoline-diyl group) ), Isoquinolylene group (isoquinolin-diyl group), oxazole-diyl group, thiazole-diyl group, oxadiazole-diyl group, benzothiazole-diyl group, benzothiadiazole-diyl group, phthalimido-diyl group, thienothiazole-diyl group Thiazolothiazole-diyl group, thienothiophene-diyl group, and thienooxazole-diyl group.

Specific examples of the divalent alicyclic group represented by A1 include a cyclopentylene group and a cyclohexylene group.

Ａ In the formula (M1-A), a1 represents an integer of 1 to 10. When a1 is 2 or more, a plurality of A1s may be the same or different.

In the formula (M1-B), A2 and A3 are each independently a divalent group selected from the group consisting of an aromatic hydrocarbon group, a heterocyclic group and an alicyclic group. Specific examples and preferred embodiments of A2 and A3 are the same as those of A1 in Formula (M1-A), and thus description thereof will be omitted.
In the formula (M1-B), a2 represents an integer of 1 to 10. When a2 is 2 or more, a plurality of A2s may be the same or different, and a plurality of A3s may be the same or different. A plurality of LA1s may be the same or different. a2 is preferably an integer of 2 or more, more preferably 2, because the effect of the present invention is more excellent.
In the formula (M1-B), when a2 is 1, LA1 is a divalent linking group. When a2 is 2 or more, the plurality of LA1s are each independently a single bond or a divalent linking group, and at least one of the LA1s is a divalent linking group. When a2 is 2, it is preferable that one of the two LA1s is a divalent linking group and the other is a single bond because the effect of the present invention is more excellent.

In the formula (M1-B), the divalent linking group represented by LA1 includes -O-,-(CH ₂ ) _g -,-(CF ₂ ) _g- , -Si (CH ₃ ) ₂ -,-( Si (CH ₃ ) ₂ O) _g -,-(OSi (CH ₃ ) ₂ ) _g- (g represents an integer of 1 to 10), -N (Z)-, -C (Z) = C ( Z ')-, -C (Z) = N-, -N = C (Z)-, -C (Z) ₂ -C (Z') _2- , -C (O)-, -OC (O) -, -C (O) O-, -OC (O) O-, -N (Z) C (O)-, -C (O) N (Z)-, -C (Z) = C ( Z ')-C (O) O-, -OC (O) -C (Z) = C (Z')-, -C (Z) = N-, -N = C (Z)-,- C (Z) = C (Z ')-C (O) N (Z ")-, -N (Z")-C (O) -C (Z) = C (Z')-, -C (Z ) = C (Z ')-C (O) -S-,-S —C (O) —C (Z) = C (Z ′) —, —C (Z) = NN = C (Z ′) — (Z, Z ′, Z ″ independently represent hydrogen, C1 to Represents a C4 alkyl group, a cycloalkyl group, an aryl group, a cyano group, or a halogen atom.), -C≡C-, -N = N-, -S-, -S (O)-, -S (O ) (O)-,-(O) S (O) O-, -O (O) S (O) O-, -SC (O)-, and -C (O) S-. Among them, -C (O) O- is preferable because the effect of the present invention is more excellent, and LA1 may be a group obtained by combining two or more of these groups.

Specific examples of M1 include, for example, the following structures. In the following specific examples, “Ac” represents an acetyl group.

Examples of the terminal group represented by T1 include a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, An alkoxycarbonyloxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms (ROC (O)-: R is an alkyl group), an acyloxy group having 1 to 10 carbon atoms, an acylamino group having 1 to 10 carbon atoms An alkoxycarbonylamino group having 1 to 10 carbon atoms, a sulfonylamino group having 1 to 10 carbon atoms, a sulfamoyl group having 1 to 10 carbon atoms, a carbamoyl group having 1 to 10 carbon atoms, a sulfinyl group having 1 to 10 carbon atoms, and And a ureido group having 1 to 10 carbon atoms, and a (meth) acryloyloxy group-containing group. Examples of the (meth) acryloyloxy group-containing group include, for example, -LA (L represents a single bond or a linking group. Specific examples of the linking group are the same as L1 and SP1 described above. A is (meth) (Representing an acryloyloxy group).
T1 is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and even more preferably a methoxy group, because the effect of the present invention is more excellent. These terminal groups may be further substituted by these groups or a polymerizable group described in JP-A-2010-244038.
The number of atoms in the main chain of T1 is preferably 1 to 20, more preferably 1 to 15, still more preferably 1 to 10, and particularly preferably 1 to 7, because the effect of the present invention is more excellent. When the number of atoms in the main chain of T1 is 20 or less, the degree of orientation of the polarizer is further improved. Here, the "main chain" in T1 means the longest molecular chain bonded to M1, and hydrogen atoms are not counted in the number of atoms in the main chain of T1. For example, when T1 is an n-butyl group, the number of atoms in the main chain is 4, and when T1 is a sec-butyl group, the number of atoms in the main chain is 3.

The content of the repeating unit (1) is preferably from 20 to 100% by mass, more preferably from 30 to 99.9% by mass, based on 100% by mass of all the repeating units of the specific compound, because the effect of the present invention is more excellent. More preferably, it is 40 to 99.0% by mass.
In the present invention, the content of each repeating unit contained in the high-molecular liquid crystalline compound is calculated based on the charged amount (mass) of each monomer used to obtain each repeating unit.
The repeating unit (1) may be contained alone in the specific compound, or two or more kinds thereof may be contained. Among them, it is preferable that two types of the repeating unit (1) are contained in the specific compound because the effect of the present invention is more excellent.

When the specific compound contains two types of repeating units (1), the terminal group represented by T1 in one (repeating unit A) is an alkoxy group, and Is preferably a group other than an alkoxy group.
In the repeating unit B, the terminal group represented by T1 is preferably an alkoxycarbonyl group, a cyano group, or a (meth) acryloyloxy group-containing group, and more preferably an alkoxycarbonyl group or a cyano group, because the effect of the present invention is more excellent. Is more preferred.
The ratio (A / B) between the content of the repeating unit A in the specific compound and the content of the repeating unit B in the specific compound is from 50/50 to 95/5 because the effect of the present invention is more excellent. , Preferably 60/40 to 93/7, and more preferably 70/30 to 90/10.

(Weight average molecular weight)
When the liquid crystal compound is a polymer liquid crystal compound, the weight average molecular weight (Mw) is preferably from 1,000 to 500,000, more preferably from 2,000 to 300,000, because the effect of the present invention is more excellent. When the Mw of the polymer liquid crystal compound is within the above range, handling of the polymer liquid crystal compound becomes easy.
In particular, the weight-average molecular weight (Mw) is preferably 10,000 to 300,000 from the viewpoint of suppressing cracks during coating.
Further, from the viewpoint of the temperature latitude of the degree of orientation, the weight average molecular weight (Mw) is preferably from 2,000 to 10,000.
Here, the weight average molecular weight and the number average molecular weight in the present invention are values measured by gel permeation chromatography (GPC). As the measurement conditions, the following conditions are exemplified as examples.
-Solvent (eluent): N-methylpyrrolidone-Equipment name: TOSOH HLC-8220GPC
・ Column: Connect and use three TOSOH TSKgelSuperAWM-H (6mm × 15cm) ・ Column temperature: 25 ° C
-Sample concentration: 0.1% by mass
・ Flow rate: 0.35 mL / min
・ Calibration curve: TOSOH TSK standard polystyrene Mw = 2800000 to 1050 (Mw / Mn = 1.03 to 1.06) Calibration curve using 7 samples

<Dichroic substance>
The dichroic substance is not particularly limited, and a visible light absorbing substance (dichroic dye), a luminescent substance (fluorescent substance, phosphorescent substance), an ultraviolet absorbing substance, an infrared absorbing substance, a nonlinear optical substance, a carbon nanotube, and Inorganic substances (for example, quantum rods) can be used, and conventionally known dichroic substances (dichroic dyes) can be used.
Specifically, for example, paragraphs [0067] to [0071] of JP-A-2013-228706, paragraphs [0008] to [0026] of JP-A-2013-227532, and [ 0008] to [0015], paragraphs [0045] to [0058] of JP 2013-14883, paragraphs [0012] to [0029] of JP 2013-109090, and JP 2013-101328. Paragraphs [0009] to [0017], paragraphs [0051] to [0065] of JP-A-2013-37353, paragraphs [0049] to [0073] of JP-A-2012-63387, and JP-A-11-305036. Paragraphs [0016] to [0018], JP-A-2001-133630, [0009] to [0011] Raku, paragraphs [0030] to [0169] of JP-A-2011-215337, paragraphs [0021] to [0075] of JP-A-2010-106242, and [0011] to [0025] of JP-A-2010-215846. Paragraphs, paragraphs [0017] to [0069] of JP-A-2011-048311, paragraphs [0013] to [0133] of JP-A-2011-213610, and paragraphs [0074] to [0246] of JP-A-2011-237513. Paragraphs, paragraphs [0022] to [0080] of Japanese Patent Application No. 2015-001425, paragraphs [0005] to [0051] of Japanese Patent Application No. 2016-0065502, and [0005] to [0041] of WO 2016/060173. Paragraph, [0008] to [0062] paragraphs of WO2016 / 136561, Japanese Patent Application Paragraphs [0014] to [0033] of JP-A-16-04909, paragraphs [0014] to [0033] of Japanese Patent Application No. 2016-044910, paragraphs [0013] to [0037] of Japanese Patent Application No. 2016-095907, and And the paragraphs [0014] to [0034] of Japanese Patent Application No. 2017-045296.

に お い て In the present invention, two or more dichroic substances may be used in combination. When two or more dichroic substances are used in combination, for example, from the viewpoint of bringing the polarizer closer to black, at least one dichroic substance having a maximum absorption wavelength in the range of 370 to 550 nm and a wavelength of 500 It is preferable to use together with at least one type of dichroic substance having a maximum absorption wavelength in the range of up to 700 nm.

The dichroic substance may have a crosslinkable group.
Specific examples of the crosslinkable group include a (meth) acryloyl group, an epoxy group, an oxetanyl group, and a styryl group. Among them, a (meth) acryloyl group is preferable.

In the present composition, the content of the dichroic substance is preferably 1 to 400 parts by mass, more preferably 2 to 100 parts by mass with respect to 100 parts by mass of the liquid crystal compound, because the effect of the present invention is more excellent. And more preferably 5 to 30 parts by mass.

When the composition contains two types of dichroic substances, a first dichroic substance and a second dichroic substance, the first dichroic substance is compatible with the liquid crystal compound. However, it is preferable that the second dichroic substance is not compatible with the liquid crystal compound. By controlling the compatibility of the first dichroic substance and the second dichroic substance with the liquid crystal compound in this manner, the orientation of the first dichroic substance and the second dichroic substance is adjusted. Can be simultaneously increased.

The compatibility between the liquid crystal compound and the first dichroic substance and the compatibility between the liquid crystal compound and the second dichroic substance can be confirmed by the following methods.
Two polarizers of an optical microscope (ECLIPSE E600 POL manufactured by Nikon) are arranged so as to be orthogonal to each other, and a sample table is set between the two polarizers. A composition in which the mixture ratio of the liquid crystal compound and the dichroic substance is changed is cast on a glass, and the glass is set on a hot stage placed on a sample table. The temperature of the hot stage is raised and lowered within the range from the melting point of the liquid crystal compound and the dichroic substance to the isotropic phase, and the phase separation state of the sample is observed. In this operation, a case where phase separation is not observed at an arbitrary mixing ratio of the liquid crystalline compound and the dichroic substance is defined as compatible, and a case where a mixing ratio at which phase separation is observed is defined as incompatible.

<Solvent>
The present composition preferably contains a solvent from the viewpoint of workability and the like.
Examples of the solvent include ketones (eg, acetone, 2-butanone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone), ethers (eg, dioxane, tetrahydrofuran, and cyclopentyl methyl ether), aliphatics Hydrocarbons (eg, hexane, etc.), alicyclic hydrocarbons (eg, cyclohexane, etc.), aromatic hydrocarbons (eg, benzene, toluene, xylene, and trimethylbenzene, etc.), and halogenated carbons (eg, , Dichloromethane, trichloromethane (chloroform), dichloroethane, dichlorobenzene, and chlorotoluene), esters (eg, methyl acetate, ethyl acetate, and butyl acetate), alcohols (eg, ethanol, , Butanol, cyclohexanol, etc.), cellosolves (eg, methyl cellosolve, ethyl cellosolve, 1,2-dimethoxyethane, etc.), cellosolve acetates, sulfoxides (eg, dimethyl sulfoxide, etc.), amides ( For example, organic solvents such as dimethylformamide and dimethylacetamide) and heterocyclic compounds (for example, pyridine) and water. These solvents may be used alone or in combination of two or more.
Of these solvents, an organic solvent is preferably used, and more preferably a halogenated carbon or ketone is used, because the effect of the present invention is more excellent.
When the composition contains a solvent, the content of the solvent is preferably from 70 to 99.5% by mass, more preferably from 80 to 99% by mass, based on the total mass of the composition, because the effect of the present invention is more excellent. %, More preferably 85 to 97% by mass.

<Interface improver>
The present composition preferably contains an interface improver because the effect of the present invention is more excellent. By including the interface improver, the smoothness of the coated surface is improved, the degree of orientation is improved, and repelling and unevenness are suppressed, so that the in-plane uniformity is expected to be improved.
As the interface improver, a compound that horizontally aligns a polymer liquid crystalline compound is preferable, and compounds (horizontal aligning agents) described in paragraphs [0253] to [0293] of JP-A-2011-237513 can be used. Further, a fluorine (meth) acrylate polymer described in paragraphs [0018] to [0043] of JP-A-2007-272185 can also be used. Compounds other than these may be used as the interface improver.
When the present composition contains an interface improver, the content of the interface improver is preferably based on 100 parts by weight of the total of the liquid crystal compound and the dichroic substance in the composition because the effect of the present invention is more excellent. , 0.001 to 5 parts by mass, preferably 0.01 to 3 parts by mass.

<Polymerization initiator>
The present composition preferably contains a polymerization initiator because the effect of the present invention is more excellent.
The polymerization initiator is not particularly limited, but is preferably a compound having photosensitivity, that is, a photopolymerization initiator.
As the photopolymerization initiator, various compounds can be used without any particular limitation. Examples of photopolymerization initiators include α-carbonyl compounds (see US Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (see US Pat. No. 2,448,828), and α-hydrocarbon-substituted aromatic compounds. Group acyloin compounds (see US Pat. No. 2,722,512), polynuclear quinone compounds (see US Pat. Nos. 3,046,127 and 2,951,758), triaryl imidazole dimer and p-aminophenyl ketone Combinations (see US Pat. No. 3,549,367), acridine and phenazine compounds (see JP-A-60-105667 and US Pat. No. 4,239,850), oxadiazole compounds (see US Pat. No. 4,221,970). ) And acylphosphineoxy (See JP-B-63-40799, JP-B-5-29234, JP-A-10-95788 and JP-A-10-29997).
Commercial products can also be used as such a photopolymerization initiator. Commercially available photopolymerization initiators include Irgacure 184, Irgacure 907, Irgacure 369, Irgacure 651, Irgacure 819, and Irgacure OXE-01 manufactured by BASF.
When the present composition contains a polymerization initiator, the content of the polymerization initiator is based on the total of 100 parts by mass of the liquid crystal compound and the dichroic substance in the composition because the effect of the present invention is more excellent. , 0.01 to 30 parts by mass, more preferably 0.1 to 15 parts by mass. When the content of the polymerization initiator is at least 0.01 part by mass, the durability of the polarizer will be good, and when it is at most 30 parts by mass, the orientation of the polarizer will be better.

<Crystallization temperature>
The crystallization temperature of the present composition is preferably from 0 to 100 ° C, more preferably from 1 to 85 ° C, because the effect of the present invention is more excellent. When the crystallization temperature of the present composition is lower than 0 ° C., a low-temperature apparatus is required to crystallize the present composition, and when the crystallization temperature of the present composition exceeds 100 ° C., haze is easily generated. Become.

The crystallization temperature of the present composition is measured according to the same procedure as the above-mentioned crystallization temperature of the polymer liquid crystal compound, except that the composition is used instead of the polymer liquid crystal compound. The crystallization temperature of the above composition is considered to be the crystallization temperature of a mixed crystal of a liquid crystalline polymer compound and a dichroic substance.

<Substituent W>
The substituent W in the present specification will be described.
Examples of the substituent W include a halogen atom, an alkyl group (including a tert-butyl group, a cycloalkyl group, a bicycloalkyl group and a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group), and alkynyl. Group, aryl group, heterocyclic group (may be referred to as heterocyclic group), cyano group, hydroxy group, nitro group, carboxy group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyl Oxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including anilino group), ammonium group, acylamino group, 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, aryl or heterocyclic azo, imide, phosphino, phosphinyl, phosphinyloxy, phosphinylamino, phosphono, silyl, hydrazino, ureido, boronic acid (-B (OH) ₂ ), a phosphato group (—OPO (OH) ₂ ), a sulfato group (—OSO ₃ H), and other known substituents.
The details of the substituent are described in paragraph [0023] of JP-A-2007-246551.

(Horizontal orientation)
As described above, in the polarizer of the present invention, the liquid crystal compound and the dichroic substance are horizontally aligned.
Here, the horizontal orientation refers to being parallel to the main surface of the polarizer, but does not require strictly parallel, and the average inclination angle with the horizontal plane is less than ± 10 °. Means The inclination angle can be measured using AxoScan OPMF-1 (manufactured by OptoScience).
Specifically, using AxoScan OPMF-1 (manufactured by OptoScience), the polarizer's Mueller matrix at a wavelength λ was measured every 10 ° from -50 to 50 ° at 10 ° at room temperature, and the surface reflection was measured. After removing the influence, the extinction coefficient ko [λ] (in-plane direction) and ke [λ] (thickness direction) are calculated by fitting to the following theoretical formula in consideration of Snell's formula and Fresnel's formula. . Unless otherwise specified, the wavelength λ is 550 nm.
k = -log (T) × λ / (4πd)
Here, T represents the transmittance, and d represents the thickness of the polarizer.
By calculating the absorbance in the in-plane direction and the thickness direction and the dichroic ratio from the calculated ko [λ] and ke [λ], it can be confirmed whether or not the liquid crystal molecules are horizontally aligned.

[Thickness]
The thickness of the polarizer of the present invention is preferably 0.1 to 5.0 μm, more preferably 0.3 to 1.5 μm, because the effect of the present invention is more excellent. Although it depends on the concentration of the dichroic substance in the composition, when the film thickness is 0.1 μm or more, a polarizer having better absorbance is obtained, and when the film thickness is 5.0 μm or less, more excellent. Is obtained.

(Production method of polarizer)
The method for producing the polarizer of the present invention is not particularly limited, but the degree of orientation of the obtained polarizer is higher, and because the haze is hardly observed, the composition described above is coated on an alignment film. It is preferable to provide a method in which a step of forming a coating film by heating, a step of orienting the dichroic substance contained in the coating film, and a step of forming the above-mentioned needle-like aggregates are provided in this order.
In the following description, the step of forming the coating film by applying the above-described composition on the alignment film is also referred to as a “coating film forming step”. Further, the step of aligning the dichroic substance contained in the coating film is also referred to as an “alignment step”. Further, the step of forming the needle-like aggregates is also referred to as an “aging step”. That is, the method for producing the polarizer of the present invention preferably includes a “coating film forming step”, an orientation step, and an “aging step” in this order.
In the following description, "the degree of orientation of the obtained polarizer is higher and haze is less likely to be observed" is also referred to as "the effect of the present invention is more excellent".
Hereinafter, each step will be described.

<Coating film forming step>
The coating film forming step is a step of forming the coating film by applying the composition described above on the alignment film. The liquid crystal compound in the coating film is horizontally aligned by the action of the alignment film. When the present composition contains an interface improver, the liquid crystalline compound in the coating film is horizontally aligned by the interaction between the alignment film and the interface improver.
By using the present composition containing the solvent described above, or by using the present composition in the form of a liquid such as a melt by heating or the like, it is easy to apply the present composition on the alignment film. Become.
The coating method of the present composition includes roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet. Publicly known methods, such as a method.

(Alignment film)
The alignment film may be any film as long as it is a film that horizontally aligns the liquid crystalline compound contained in the present composition.
Rubbing treatment of organic compound (preferably polymer) on the film surface, oblique deposition of inorganic compound, formation of layer having microgrooves, or organic compound (eg, ω-tricosanoic acid, It can be provided by such means as accumulation of dioctadecylmethyl ammonium chloride (methyl stearylate). Further, there is known an alignment film in which an alignment function is generated by application of an electric field, a magnetic field, or light irradiation. Among them, in the present invention, an alignment film formed by rubbing treatment is preferable from the viewpoint of easy control of the pretilt angle of the alignment film, and an optical alignment film formed by light irradiation is also preferable from the viewpoint of uniformity of alignment.

(1) Rubbing Treatment Orientation Film As the polymer material used for the orientation film formed by the rubbing treatment, there are many publications, and many commercial products can be obtained. In the present invention, polyvinyl alcohol or polyimide, and derivatives thereof are preferably used. For the alignment film, reference can be made to the description from page 43, line 24 to page 49, line 8 of WO 2001/88574 A1. The thickness of the alignment film is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm.

(2) Photo-Alignment Film Photo-alignment materials used for the alignment film formed by light irradiation are described in many documents and the like. In the present invention, for example, JP-A-2006-285197, JP-A-2007-76839, JP-A-2007-138138, JP-A-2007-94071, and JP-A-2007-121721. Azo compounds described in JP-A-2007-140465, JP-A-2007-156439, JP-A-2007-133184, JP-A-2009-109831, JP-A-3883848, and JP-A-4151746. Aromatic ester compounds described in 2002-229039, maleimide and / or alkenyl-substituted nadimide compounds having a photo-alignable unit described in JP-A-2002-265541 and JP-A-2002-317013, Patent No. 4205195 Patent No. 4205198 Photocrosslinkable silane derivative of the mounting, Kohyo 2003-520878, JP-T-2004-529220 and JP-well, and a photocrosslinkable polyimide, polyamide or ester are preferable examples described in Japanese Patent No. 4162850. More preferably, the photo-alignment material includes an azo compound, a photo-crosslinkable polyimide, a polyamide, an ester, and the like.

The photo-alignment film formed from the above materials is irradiated with linearly polarized light or non-polarized light to produce a photo-alignment film.
In this specification, “irradiation of linearly polarized light” and “irradiation of non-polarized light” are operations for causing a photoreaction to occur in a photo-alignment material. The wavelength of the light used depends on the photo-alignment material used, and is not particularly limited as long as it is necessary for the photoreaction. The peak wavelength of light used for light irradiation is preferably from 200 to 700 nm, more preferably ultraviolet light having a peak wavelength of light of 400 nm or less.

The light source used for light irradiation may be a commonly used light source, for example, a lamp such as a tungsten lamp, a halogen lamp, a xenon lamp, a xenon flash lamp, a mercury lamp, a mercury xenon lamp, and a carbon arc lamp, and various lasers (for example, a semiconductor laser, a helium lamp). Examples include a neon laser, an argon ion laser, a helium cadmium laser, a YAG (yttrium aluminum garnet) laser, a light emitting diode, and a cathode ray tube.

As means for obtaining linearly polarized light, a method using a polarizing plate (for example, an iodine polarizing plate, a dichroic substance polarizing plate, and a wire grid polarizing plate), a prism element (for example, a Glan-Thompson prism) or a Brewster angle is used. A method using a reflective polarizer used, a method using light emitted from a laser light source having polarized light, and the like can be adopted. Alternatively, only light having a required wavelength may be selectively irradiated using a filter or a wavelength conversion element.

In the case of linearly polarized light, a method of irradiating light from the upper surface or the back surface of the alignment film to the surface of the alignment film perpendicularly or obliquely is employed. The incident angle of light varies depending on the photo-alignment material, but is preferably 0 to 90 ° (vertical), and more preferably 40 to 90 °.
In the case of non-polarized light, the alignment film is irradiated with non-polarized light obliquely. The incident angle is preferably from 10 to 80 °, more preferably from 20 to 60 °, even more preferably from 30 to 50 °.
The irradiation time is preferably 1 to 60 minutes, more preferably 1 to 10 minutes.

When patterning is required, a method of performing light irradiation using a photomask as many times as necessary for pattern formation, or a method of writing a pattern by laser light scanning can be employed.

<Orientation process>
The alignment step is a step of aligning the dichroic substance contained in the coating film.
In the alignment step, it is considered that the dichroic substance is aligned along the liquid crystal compound aligned by the alignment film.
The orientation step may include a drying process. By the drying treatment, components such as a solvent can be removed from the coating film. The drying treatment may be performed by a method of leaving the coating film at room temperature for a predetermined time (for example, natural drying), or may be performed by a method of heating and / or blowing.
Here, the dichroic substance contained in the present composition may be oriented by the above-mentioned coating film forming step or drying treatment. For example, in an embodiment in which the composition is prepared as a coating solution containing a solvent, the dichroic substance contained in the coating film is oriented by drying the coating film and removing the solvent from the coating film. In some cases, the polarizer of the present invention can be obtained.

The orientation step preferably includes a heat treatment. Thereby, the dichroic substance contained in the coating film is more oriented, and the degree of orientation of the obtained polarizer is higher.
The heat treatment is preferably performed at 10 to 250 ° C., more preferably 25 to 190 ° C., from the viewpoint of production suitability. Further, the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

The orientation step may include a cooling treatment performed after the heat treatment. The cooling process is a process of cooling the coated film after heating to about room temperature (20 to 25 ° C.). Thereby, the orientation of the dichroic substance contained in the coating film is fixed more, and the degree of orientation of the obtained polarizer is further increased. The cooling means is not particularly limited, and can be implemented by a known method.

<Aging process>
The aging step is a step for forming the above-mentioned acicular aggregate by performing a heat treatment again after performing the orientation step, and obtaining the polarizer of the present invention.
As will be described later in Examples (Comparative Example 1), a large number of small dot-like (island-like) aggregates are formed after the orientation step is performed (see FIG. 3). After performing the orientation step, by performing the aging step, the small point-like aggregates are further aggregated to produce needle-like aggregates having the aspect ratio as described above, and the present invention having a high degree of orientation Can be obtained.

The state of formation of the acicular aggregates varies depending on the types of the liquid crystal compound and the dichroic substance.
Therefore, the temperature of the heat treatment in the aging step may be appropriately set at a temperature at which an acicular aggregate can be formed depending on the liquid crystalline compound and the dichroic substance used. If the temperature of the aging treatment is too low, the needle-like aggregates cannot be formed sufficiently.If the temperature of the aging treatment is too high, the aggregation proceeds too much, the aspect ratio of the aggregates becomes small, and the needle-like aggregates are sufficiently formed. And the length of the aggregate becomes long (see FIG. 4).
The temperature of the heat treatment in the aging step is preferably from 40 to 130 ° C, more preferably from 60 to 110 ° C.

Similarly, as for the time of the heat treatment in the aging step, the time during which the needle-like aggregate can be formed may be appropriately set according to the liquid crystal compound and the dichroic substance used. If the aging time is too short, the needle-like aggregates cannot be formed sufficiently, and if the aging time is too long, the aggregation proceeds too much, the aspect ratio of the aggregates becomes small, and the needle-like aggregates become And the length of the aggregate becomes long.
The time of the heat treatment in the aging step is preferably 0.5 to 120 seconds, more preferably 1 to 100 seconds.

In the aging step, similarly to the above-described orientation step, a cooling treatment may be provided after the heat treatment. The cooling treatment may be performed in the same manner as the cooling treatment in the orientation step.

<Other steps>
This manufacturing method may include a step of curing the polarizer after the aging step. In the following description, the step of curing the polarizer is also referred to as a “curing step”.
The curing step is performed by, for example, heating and / or light irradiation (exposure). Among these, the curing step is preferably performed by light irradiation.
Various light sources such as infrared light, visible light, and ultraviolet light can be used as the light source for curing, but ultraviolet light is preferable. In addition, ultraviolet rays may be irradiated while heating at the time of curing, or ultraviolet rays may be irradiated through a filter that transmits only a specific wavelength.
Further, the exposure may be performed under a nitrogen atmosphere. In the case where the curing of the polarizer proceeds by radical polymerization, inhibition of polymerization by oxygen is reduced, so that exposure is preferably performed in a nitrogen atmosphere.

[Laminate]
The polarizer of the present invention is usually a laminated body laminated with another member (sheet-like material).
As an example, the laminate including the polarizer of the present invention has a base material, an alignment film provided on the base material, and the polarizer of the present invention provided on the alignment film.
Further, the laminate may have a λ / 4 plate on the polarizer of the present invention. Further, the laminate may have a barrier layer on the polarizer of the present invention. Therefore, when the laminate has a λ / 4 plate, the barrier layer is provided between the polarizer of the present invention and the λ / 4 plate.
Hereinafter, each layer constituting the laminate including the polarizer of the present invention will be described.

〔Base material〕
The substrate can be appropriately selected and includes, for example, glass and a polymer film. The light transmittance of the substrate is preferably 80% or more.
When a polymer film is used as the substrate, it is preferable to use an optically isotropic polymer film. For specific examples and preferred embodiments of the polymer, the description in paragraph [0013] of JP-A-2002-22942 can be applied. In addition, even if it is a conventionally known polymer such as polycarbonate or polysulfone which easily develops birefringence, a polymer whose expression is reduced by modifying the molecule described in WO2000 / 26705 should be used. You can also.

(Alignment film)
Since the orientation film is as described above, its description is omitted.

(Polarizer)
Since the polarizer of the present invention is as described above, the description thereof will be omitted.

[Λ / 4 plate]
The “λ / 4 plate” is a plate having a λ / 4 function, specifically, a plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light (or converting circularly polarized light into linearly polarized light). It is.
For example, specific embodiments of the λ / 4 plate having a single-layer structure include a stretched polymer film and a retardation film having an optically anisotropic layer having a λ / 4 function on a support. No. Further, as a mode in which the λ / 4 plate has a multilayer structure, specifically, there is a broadband λ / 4 plate obtained by laminating a λ / 4 plate and a λ / 2 plate.
The λ / 4 plate and the polarizer of the present invention may be provided in contact with each other, or another layer may be provided between the λ / 4 plate and the polarizer of the present invention. Examples of such a layer include an adhesive layer or an adhesive layer for ensuring adhesion, and a barrier layer.

[Barrier layer]
When the laminate includes a barrier layer, the barrier layer is provided on the polarizer of the present invention. Therefore, when the laminate has a λ / 4 plate, the barrier layer is provided between the polarizer of the present invention and the λ / 4 plate. When a layer other than the barrier layer (for example, an adhesive layer or an adhesive layer) is provided between the polarizer of the present invention and the λ / 4 plate, the barrier layer is formed of, for example, the polarizer of the present invention. And another layer.
The barrier layer is a layer that functions as a protective layer for protecting the polarizer of the present invention in the laminate. Examples of such a barrier layer include various transparent resin layers.
The barrier layer may have a gas barrier property (oxygen barrier property) in order to protect the polarizer of the present invention from a gas such as oxygen in the atmosphere, moisture, or a compound contained in an adjacent layer. .
The barrier layer having gas barrier properties is described in, for example, paragraphs [0014] to [0054] of JP-A-2014-159124, paragraphs [0042] to [0075] of JP-A-2017-121721, and JP-A-2017-127. JP-A-115076, paragraphs [0045] to [0054], JP-A-2012-213938, paragraphs [0010] to [0061], and JP-A-2005-169994, paragraphs [0021] to [0031]. The description can be referred to.

[Application]
The laminate of the present invention can be used, for example, as a polarizing element (polarizing plate), for example, as a linear polarizing plate or a circular polarizing plate.
When the laminate of the present invention does not have an optically anisotropic layer such as the λ / 4 plate, the laminate can be used as a linear polarizing plate.
On the other hand, when the laminate of the present invention has the λ / 4 plate, the laminate can be used as a circularly polarizing plate.

[Image display device]
The image display device of the present invention is an image display device having the above-described polarizer of the present invention.
The display element used in the image display device of the present invention is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence display panel, and a plasma display panel. In the following description, electroluminescence is abbreviated as “EL”.
Among these, a liquid crystal cell or an organic EL display panel is preferable, and a liquid crystal cell is more preferable. That is, the image display device of the present invention is preferably a liquid crystal display device using a liquid crystal cell as a display element, an organic EL display device using an organic EL display panel as a display element, and a liquid crystal display device is preferred. More preferred.

(Liquid crystal display)
As a liquid crystal display device which is an example of the image display device of the present invention, an embodiment having the above-described polarizer of the present invention and a liquid crystal cell is preferably exemplified. More preferably, the present invention is a liquid crystal display device including the above-described laminate of the present invention (not including a λ / 4 plate) and a liquid crystal cell.
In the present invention, of the polarizing elements provided on both sides of the liquid crystal cell, it is preferable to use the laminate of the present invention as a front-side polarizing element, and to use the laminate of the present invention as a front-side and rear-side polarizing element. It is more preferable to use
Hereinafter, a liquid crystal cell included in the liquid crystal display device will be described in detail.

<Liquid crystal cell>
The liquid crystal cell used in the liquid crystal display device is preferably a VA (Vertical Alignment) mode, an OCB (Optically Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode. However, the present invention is not limited to these.
In the TN mode liquid crystal cell, rod-like liquid crystalline molecules are substantially horizontally aligned when no voltage is applied, and further twist-aligned at 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT (Thin Film Transistor) liquid crystal display device, and is described in many documents.
In a VA mode liquid crystal cell, rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied. VA mode liquid crystal cells include:
(1) In addition to a narrowly defined VA mode liquid crystal cell (described in JP-A-2-176625) in which rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied and are aligned substantially horizontally when voltage is applied. ,
(2) A liquid crystal cell in which the VA mode is multi-domain (in the MVA mode) for expanding the viewing angle (described in SID97, Digest of Tech. Papers (Preliminary Collection) 28 (1997) 845),
(3) A liquid crystal cell (n-ASM mode) in which rod-like liquid crystal molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is performed when a voltage is applied (Preprints 58-59 (1998) ) Described), and
(4) Includes SURVIVAL mode liquid crystal cell (presented at LCD International 98).
Further, the VA mode liquid crystal cell may be any of a PVA (Patterned Vertical Alignment) type, a photo alignment type (Optical Alignment), and a PSA (Polymer-Sustained Alignment).
Details of these modes are described in JP-A-2006-215326 and JP-T-2008-538819.
In the IPS mode liquid crystal cell, rod-like liquid crystal molecules are oriented substantially parallel to the substrate, and the liquid crystal molecules respond planarly when an electric field parallel to the substrate surface is applied. In the IPS mode, black display is performed when no electric field is applied, and the absorption axes of a pair of upper and lower polarizing plates are orthogonal to each other. Regarding the IPS mode, Japanese Patent Application Laid-Open Nos. 10-54982 and 11-202323 disclose a method of using an optical compensation sheet to reduce leakage light at the time of black display in an oblique direction and improve the viewing angle. It is disclosed in JP-A-9-292522, JP-A-11-133408, JP-A-11-305217, and JP-A-10-307291.

[Organic EL display]
As an organic EL display device as an example of the image display device of the present invention, for example, an embodiment having the polarizer of the present invention described above, a λ / 4 plate, and an organic EL display panel in this order from the viewing side. Are preferred.
More preferably, the laminated body of the present invention having the λ / 4 plate and the organic EL display panel are arranged in this order from the viewing side. In this case, the laminated body is arranged from the viewer side in the order of the base material, the alignment film, the polarizer of the present invention, the barrier layer provided as necessary, and the λ / 4 plate.
The organic EL display panel is a display panel configured using an organic EL element having an organic light emitting layer (organic EL layer) sandwiched between electrodes (between a cathode and an anode). The configuration of the organic EL display panel is not particularly limited, and a known configuration is employed.

本 Hereinafter, the present invention will be described in more detail with reference to Examples. Materials, used amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed 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 following examples.

[Synthesis Example 1]

二 According to the following route, dichroic substance C1 was synthesized.

4-Nitrophenol (27.8 g), 11-bromoundecanol (44.6 g), and potassium carbonate (30.4 g) are dissolved in N, N-dimethylacetamide (DMAc) (150 mL (milliliter)). The mixture was stirred at 105 ° C. for 2 hours. The temperature was lowered to room temperature, and the mixture was separated and washed with ethyl acetate / 10% ammonium chloride aqueous solution. The organic layer was dried over magnesium sulfate and concentrated to obtain a white solid.
Next, DMAc (150 mL) was added to the white solid, and the mixture was stirred in an ice bath. Acrylic acid chloride (18.1 g) was added dropwise while maintaining the temperature of the reaction system at 15 ° C. or lower, and the mixture was stirred at room temperature for 1 hour after being appropriately cooled. Thereafter, ethyl acetate and a 10% aqueous ammonium chloride solution were added to carry out liquid separation and washing. After drying over magnesium sulfate, the mixture was concentrated to obtain a yellow solid C1-1.
Separately, Fe powder (89.4 g, 1.6 mol), ammonium chloride (8.9 g, 166 mmol), 2-propanol (210 mL), and pure water (88 mL) were mixed and refluxed at 105 ° C. externally. Yellow solid C1-1 dissolved in 2-propanol (88 mL) by heating was dropped into the refluxed system. After the completion of the dropwise addition, the reaction was carried out for 30 minutes under reflux. After cooling to room temperature, iron powder was removed by celite filtration, the filtrate was separated by adding ethyl acetate and water, and the organic layer was washed three times with water.
The organic layer was dried over sodium sulfate and concentrated. Purification by a column gave 8.0 g of compound C1-2.

2-Aminothiophene was synthesized from 2-nitrothiophene according to the method described in the literature (Journal of Medicinal Chemistry, 2005, Vol. 48, p. 5794).
Compound C1-2 (5.5 g) obtained above was added to a mixture of 12 mol / L (liter) hydrochloric acid (15 mL), pure water (30 mL), and THF (tetrahydrofuran) (30 mL). Thereafter, the mixture was cooled to an internal temperature of 5 ° C. or lower, and sodium nitrite (1.4 g) was dissolved in pure water (9 mL) and added dropwise. Further, the mixture was stirred at an internal temperature of 5 ° C. or lower for 1 hour to prepare a diazonium solution.
Next, 2-aminothiophene hydrochloride (2.4 g) was dissolved in pure water (12 mL) and hydrochloric acid (6 mL), and the diazonium solution prepared above was added dropwise at an internal temperature of 0 ° C. The reaction was warmed to room temperature and stirred for 2 hours.
The precipitated solid was separated by filtration and dried to obtain 6.1 g of a red-orange solid C1-3.

The red-orange solid C1-3 (5.6 g) obtained above was suspended and dissolved in acetic acid (100 mL), and sodium thiocyanate (1.5 g) was added at room temperature. While cooling with water and maintaining the internal temperature at 20 ° C. or lower, bromine (2.0 g, 24.8 mmol) was added dropwise.
After stirring at room temperature for 2 hours, pure water (100 mL) was added, and the obtained solid was separated by filtration and dried to obtain 5.5 g of a black solid C1-4.

The black solid C1-4 (4.7 g) obtained above is added to hydrochloric acid (6 mL) and acetic acid (6 mL). After stirring for 1 hour, amidosulfuric acid (0.52 mg) was added to obtain a diazonium solution.
A diazonium solution was added dropwise while maintaining a 10 mL methanol solution of N-ethyl-N- (2-acryloyloxyethyl) aniline (2.3 g) at 0 ° C. or lower. After heating to room temperature and stirring for 1 hour, pure water (30 mL) was added, and the obtained solid was separated by filtration.
Purification by a column yielded 0.51 g of a compound (dichroic substance C1) as a black-purple solid represented by the formula C1. The ¹ H-NMR (Nuclear Magnetic Resonance) data of the obtained dichroic substance C1 is shown below.
In addition, N-ethyl-N- (2-acryloyloxyethyl) aniline was synthesized from N-ethylaniline as a raw material by US Pat. No. 7,601,849 and a known method.
¹ H-NMR data (CDCl ₃ ) δ: 1.20-1.50 (m, 17H), 1.60-1.90 (m, 8H) 3.40 (t, 2H), 3.50 (t) , 2H), 4.05 (t, 2H), 4.10 (t, 2H), 4.20 (t, 2H), 5.80-5.85 (d, 2H), 6.10-6. 15 (dd, 2H), 6.38-6.43 (d × 2, 2H), 6.70 (d, 2H), 7.00 (d, 2H), 7.82 (s, 1H) 88 (d, 2H), 7.95 (d, 2H)

[Synthesis Example 2]
According to the following route, a dichroic substance Y1 was synthesized.

First, 10 g of compound Y1-1 was synthesized according to the literature (Chem. Eur. J. 2004.10.2011).
Compound Y1-1 (10 g) was dissolved in pure water (300 mL) and hydrochloric acid (17 mL), cooled in an ice bath, sodium nitrite (3.3 g) was added, and the mixture was stirred for 30 minutes. After addition of amidosulfuric acid (0.5 g), m-toluidine (5.1 g) was added and the mixture was stirred at room temperature for 1 hour. After stirring, the solid obtained by neutralization with hydrochloric acid was collected by suction filtration to obtain 3.2 g of compound Y1-2.
Compound Y1-2 (1.0 g) was dissolved in a THF solution consisting of THF (30 mL), water (10 mL), and hydrochloric acid (1.6 mL), cooled in an ice bath, and treated with sodium nitrite (0.3 g). ) Was added and the mixture was stirred for 30 minutes, and then amidosulfuric acid (0.5 g) was added. Separately, phenol (0.4 g) was dissolved in potassium carbonate (2.76 g) and pure water (50 mL), and after cooling in an ice bath, the above THF solution was added dropwise and stirred at room temperature for 1 hour. After stirring, water (200 mL) was added, and the precipitated solid was separated by suction filtration to obtain 1.7 g of a compound Y1-3.
Compound Y1-3 (0.6 g), compound y1 (0.8 g) shown in the above route and potassium carbonate (0.95 g) were dissolved in DMAc (30 mL, dimethylacetamide) and stirred at 90 ° C. for 3.5 hours. . After stirring, pure water (300 mL) was added, and the precipitated solid was filtered off by suction filtration to obtain 0.3 g of a yellow-orange solid compound (dichroic substance Y1) represented by the formula Y1. The ¹ H-NMR data of the obtained dichroic substance Y1 is shown below.
¹ H-NMR data (CDCl ₃ ) δ: 1.93 (m, 8H), 4.11 (m, 4H), 4.29 (m, 4H), 5.83-5.87 (d, 2H) , 6.10-6.18 (dd, 2H), 6.39-6.45 (d, 2H), 7.02 (d, 2H), 7.77-8.13 (m, 15H)

[Synthesis Example 3]

液晶 The liquid crystal compound L1 was synthesized by the following procedure.

(Synthesis of Compound L1-2)

To a solution of butylparaben (201 g) in N, N-dimethylformamide (300 mL) were added 2-chloroethoxyethoxyethanol (244 g) and potassium carbonate (200 g). After stirring at 95 ° C. for 9 hours, toluene (262 mL) and pure water (660 mL) were added, and concentrated hydrochloric acid (147 g) was added dropwise. After stirring for 10 minutes, the mixture was allowed to stand, and the reaction solution was washed by a liquid separation operation. To the obtained organic layer, a 28% by mass sodium methoxide methanol solution (500 g) and pure water (402 mL) were added, and the mixture was stirred at 50 ° C. for 2 hours.
Thereafter, the organic solvent was distilled off by concentration, pure water (402 mL) was added, and the mixture was concentrated again at 50 ° C. until the weight became 1.13 kg. Pure water (478 mL) was added to the resulting solution, and concentrated hydrochloric acid (278 g) was added dropwise. Ethyl acetate (1.45 kg) was added thereto, and the mixture was stirred at 30 ° C for 10 minutes, and the aqueous layer was removed by a liquid separation operation. Next, a 20% by mass aqueous sodium chloride solution (960 mL) was added, the mixture was stirred at 30 ° C. for 10 minutes, and the aqueous layer was removed by a liquid separation operation. N-methylpyrrolidone (824 g) was added to the obtained organic layer, and the mixture was concentrated at 70 ° C. for 4 hours to obtain 1.13 kg of an N-methylpyrrolidone solution containing compound L1-1.
The next step was performed using 1085 g of the obtained N-methylpyrrolidone solution containing the compound L1-1. To an N-methylpyrrolidone solution (1085 g) containing the obtained compound L1-1, N, N-dimethylaniline (189 g) and 2,2,6,6-tetramethylpiperazine (1.5 g) were added. After cooling, acrylic acid chloride (122 g) was added dropwise so that the internal temperature did not exceed 10 ° C.
After stirring at an internal temperature of 10 ° C. for 2 hours, methanol (81 g) was added dropwise and stirred for 30 minutes. Ethyl acetate (1.66 kg), 10 wt% saline (700 mL), and 1N aqueous hydrochloric acid (840 mL) were added thereto, and the aqueous layer was removed by liquid separation. Next, a 10 wt% saline solution (800 mL) was added, the mixture was stirred at 30 ° C. for 10 minutes, and the aqueous layer was removed by a liquid separation operation. Next, a 20 wt% saline solution (800 mL) was added, the mixture was stirred at 30 ° C. for 10 minutes, and the aqueous layer was removed by a liquid separation operation.
A mixed solvent of hexane / isopropyl alcohol (1780 mL / 900 mL) was added to the obtained organic layer, the mixture was cooled to 5 ° C., stirred for 30 minutes, and then filtered to obtain 209 g of a white solid compound L1-2. Was obtained (3 step yield: 65%).

The ¹ H-NMR data of the obtained compound L1-2 are shown below.
¹ H-NMR (solvent: CDCl ₃ ) δ (ppm): 3.67-3.78 (m, 6H), 3.87-3.92 (m, 2H), 4.18-4.23 (m , 2H), 4.31-4.35 (m, 2H), 5.80-5.85 (m, 1H), 6.11-6.19 (m, 1H), 6.40-6.46. (M, 1H), 6.93-6.98 (m, 2H), 8.02-8.07 (m, 2H)

(Synthesis of Compound L1-3)

Dibutylhydroxytoluene (BHT) (200 mg) was added to a THF solution (70 mL) of methanesulfonyl chloride (MsCl) (73.4 mmol, 5.7 mL), and the internal temperature was cooled to −5 ° C.
Thereto, a THF solution of compound L1-2 (66.7 mmol, 21.6 g) and diisopropylethylamine (DIPEA) (75.6 mmol, 13.0 mL) was added dropwise so that the internal temperature did not rise to 0 ° C. or higher. . After stirring at −5 ° C. for 30 minutes, N, N-dimethyl-4-aminopyridine (DMAP) (200 mg) was added, and diisopropylethylamine (75.6 mmol, 13.0 mL) and 4-hydroxy-4′-methoxy were added. A solution of biphenyl (60.6 mmol, 12.1 g) in tetrahydrofuran (THF) and dimethylacetamide (DMAc) was added dropwise so that the internal temperature did not rise to 0 ° C. or higher. Thereafter, the mixture was stirred at room temperature for 4 hours.
After stopping the reaction by adding methanol (5 mL), water and ethyl acetate were added. The solvent was removed from the organic layer extracted with ethyl acetate using a rotary evaporator, and purification was performed by column chromatography using ethyl acetate and hexane to obtain 18.7 g of a compound L1-3 as a white solid (yield). 61%). In the structural formula, Me represents a methyl group.

The ¹ H-NMR data of the obtained compound L1-3 are shown below.
¹ H-NMR (solvent: CDCl ₃ ) δ (ppm): 3.65-3.82 (m, 6H), 3.85 (s, 3H), 3.85-3.95 (m, 2H), 4.18-4.28 (m, 2H), 4.28-4.40 (m, 2H), 5.82 (dd, 1H), 6.15 (dd, 1H), 6.43 (dd, 1H), 6.90-7.05 (m, 4H), 7.20-7.30 (m, 2H), 7.45-7.65 (m, 4H), 8.10-8.20 ( m, 2H)

The impurities include the following compounds L1-b.

(Synthesis of Compound L1-23)

{Journal of Polymer Polymer Science, Part A: Polymer Chemistry, 2012, vol. 50, p. According to the method described in 3936-3943, methyl 4- (4-hydroxyphenyl) benzoate was synthesized.

To a solution of methanesulfonyl chloride (MsCl) (54.8 mmol, 6.27 g) in ethyl acetate (44 mL) was added 2,2,6,6-tetramethylpiperidine 1-oxyl (68 mg), and the internal temperature was lowered to −5 ° C. Cool.
The compound L1-2 (52.6 mmol, 17.1 g) synthesized as described above and a THF solution of diisopropylethylamine (DIPEA) (57.0 mol, 7.36 g) were heated to an internal temperature of 0 ° C. or higher. Drip so as not to. After stirring at −5 ° C. for 30 minutes, a DMAc solution of methyl 4- (4-hydroxyphenyl) benzoate (43.8 mmol, 10.0 g) and N-methyl-imidazole (NMI) (1.8 g) were added. Diisopropylethylamine (75.6 mmol, 13.0 mL) was added dropwise so that the internal temperature did not rise above 0 ° C. Thereafter, the mixture was stirred at room temperature for 4 hours, and water and ethyl acetate were added to stop the reaction.
The obtained reaction solution was separated, and the organic layer extracted with ethyl acetate was purified by column chromatography using ethyl acetate and hexane after removing the solvent with a rotary evaporator to obtain 20.4 g of a white solid. Was obtained (yield 87%).

The ¹ H-NMR data of the obtained compound L1-23 are shown below.
¹ H-NMR (solvent: CDCl ₃ ) δ (ppm): 3.68-3.80 (m, 6H), 3.87-3.95 (m, 2H), 3.95 (s, 3H), 4.20-4.27 (m, 2H), 4.31-4.37 (m, 2H), 5.83 (dd, 1H), 6.16 (dd, 1H), 6.43 (dd, 1H), 6.97-7.05 (m, 2H), 7.28-7.35 (m, 2H), 7.64-7.72 (m, 4H), 8.08-8.20 ( m, 4H)

The impurities include the following compounds L1-b2.

(Synthesis of Liquid Crystal Compound L1)

Compound L1-3 (84 g), compound L1-23 (21 g), and dibutylhydroxytoluene (BHT) (158 mg) were dissolved in anisole (337 g). Thereto, 2,2'-azobis (2-methylpropionic acid) dimethyl (1660 mg) (V-601, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added at room temperature and stirred.
The obtained anisole solution was dropped into anisole (84 g) heated to 80 ° C. in a nitrogen atmosphere over 2 hours, and after completion of the dropping, stirred at 80 ° C. for 4 hours.
The obtained reaction solution was added dropwise to methanol (1080 mL), and the precipitate was collected by filtration. The residue was washed with acetonitrile to obtain 100 g of a white solid, liquid crystal compound L1 (yield). 95%). The weight average molecular weight (Mw) of the obtained polymer was 13,300.
The molecular weight was calculated by gel permeation chromatography (GPC) in terms of polystyrene. The column used was connected to three TOSOH TSKgelSuperAWM-H (manufactured by Tosoh Corporation), and the solvent used was N-methylpyrrolidone.

[Example 1]
<Preparation of transparent support>
A polyvinyl alcohol (PVA) coating solution having the following composition was continuously applied to a 40 μm-thick TAC substrate (TG40, manufactured by FUJIFILM Corporation) using a # 8 wire bar. Thereafter, by drying with hot air at 100 ° C. for 2 minutes, a transparent support having a 0.8 μm-thick PVA film made of modified polyvinyl alcohol (PVA-1) formed on a TAC substrate was obtained.
―――――――――――――――――――――――――――――――――
Composition of PVA coating liquid ――――――――――――――――――――――――――――――――
-2.00 parts by mass of modified polyvinyl alcohol (PVA-1)-74.08 parts by mass of water-23.86 parts by mass of methanol-Photopolymerization initiator (IRGACURE 2959, manufactured by BASF)
0.06 parts by mass ――――――――――――――――――――――――――――――――――

Modified polyvinyl alcohol PVA-1

<Preparation of alignment film>
Butoxyethanol (41.6 parts by mass), dipropylene glycol monomethyl (41.6 parts by mass), and pure water (15.8 parts by mass) were added to the photo-alignment material E-1 (1 part by mass) having the following structure. In addition, the obtained solution was subjected to pressure filtration with a 0.45 μm membrane filter to prepare a composition for forming an alignment film.
Next, the obtained composition for forming an alignment film was applied on a transparent support, and dried at 60 ° C. for 1 minute. Thereafter, the obtained coating film was irradiated with linearly polarized ultraviolet light (illuminance: 4.5 mW, irradiation amount: 500 mJ / cm ² ) using a polarized ultraviolet light exposure device to prepare an alignment film.

<Preparation of Polarizer 1>
The following polarizer-forming composition was continuously applied on the prepared alignment film using a # 7 wire bar to form a coating film.
Next, the coating film was heated at 140 ° C. for 90 seconds, and cooled to room temperature (23 ° C.).
Next, as a ripening step, the coating film was heated at 90 ° C. for 60 seconds and cooled again to room temperature.
Thereafter, the polarizer 1 was formed on the alignment film by irradiating the film with an irradiance of 28 mW / cm ² for 60 seconds using a high-pressure mercury lamp.
―――――――――――――――――――――――――――――――――
Composition of composition for forming polarizer ――――――――――――――――――――――――――――――――
-7.207 parts by mass of liquid crystal compound L1-0.943 parts by mass of dichroic substance Y1-0.216 parts by mass of dichroic substance C1-0.061 parts by mass of the following interface modifier F1-Polymerization initiator (BASF) Manufactured by IRGACURE 819)
0.073 parts by mass, cyclopentanone 45.750 parts by mass, tetrahydrofuran 45.750 parts by mass ――――――――――――――――――――――――――――― ――――

The polarizer 1 was set in a hydrophilic treatment apparatus (manufactured by JEOL Ltd., HDT-400), and subjected to a hydrophilic treatment for 10 minutes in a GRID mode. Next, the hydrophilic polarizer 1 was set in a vacuum evaporation machine (JEE-400, manufactured by JEOL Ltd.), and carbon having a thickness of about 10 nm was evaporated.
The polarizer 1 on which carbon was deposited was set on an SEM (SU8030 type FE-SEM, manufactured by Hitachi High-Technologies Corporation) while being tilted by 30 ° with the orientation axis as a rotation axis from a state where the polarizer was placed on a horizontal surface, and the electron beam acceleration voltage was 2 kV. Under the conditions of secondary electron detection, an SEM observation image of the surface of the polarizer 1 was obtained such that the orientation axis was in the lateral direction of the SEM image. FIG. 2 shows an SEM observation image of the surface of the polarizer 1.

Using the image processing software “ImageJ”, an image was created in which the brightness of the acquired SEM observation image of the surface of the polarizer 1 was binarized. Among the plurality of high brightness regions of the created binarized image, those having an area equal to or more than an area equivalent to a circle having a diameter of 50 nm (1963 nm ² ) were extracted as aggregates. The binarization of the brightness of the surface SEM observation image is performed by creating a brightness histogram of the SEM observation image, extracting the brightness having the highest frequency from the created brightness histogram, and obtaining a brightness 1.2 times the extracted brightness. Was performed as a threshold value.
Then, using the same software, each extracted aggregate is approximated by an ellipse, the length of the major axis of the approximated ellipse is set to the length L of the major axis of the aggregate, and the length of the minor axis of the approximated ellipse is defined by the aggregate. Is the length D of the short axis.
After measuring the length L of the major axis and the length D of the minor axis of each aggregate in this manner, the aspect ratio was determined in three arbitrarily selected 13.58 μm ² non-overlapping regions. Was greater than 2 (L / D> 2) and the length L satisfies 300 nm or more (L ≧ 300 nm). The needle-like aggregates of the present invention were extracted, counted, and totaled. Further, the ratio of the needle-like aggregates having a length L of 500 nm or less (L ≦ 500 nm) in the needle-like aggregates thus extracted was calculated.
The counting of such needle-like aggregates and the calculation of the ratio of needle-like aggregates satisfying L ≦ 500 nm were arbitrarily selected in a region of 40 μm ² (13.58 μm ² × 3) that does not overlap each other, and 10 places. The average was defined as the number of needle-like aggregates per 40 μm ² in the polarizer 1 and the ratio of needle-like aggregates satisfying L ≦ 500 nm.
As a result, the number of needle-like aggregates per 40 μm ² was 65, and the ratio of needle-like aggregates having a length L of 500 nm or less was 95.4%.

<Formation of transparent resin layer (barrier layer)>
The following curable composition was continuously applied onto the polarizer 1 with a # 2 wire bar, and dried at 60 ° C. for 5 minutes.
Thereafter, irradiation was performed for 60 seconds using a high-pressure mercury lamp under an irradiation condition of an illuminance of 28 mW / cm ² to cure the following curable composition, and a laminate in which a transparent resin layer (barrier layer) was formed on the polarizer 1 was formed. Produced. Thus, a laminate 1 of Example 1 was obtained.

―――――――――――――――――――――――――――――――――
Curable composition ――――――――――――――――――――――――――――――――
・ Polymerizable compound KAYARAD PET-30 (Nippon Kayaku Co., Ltd.)
29 parts by weight, polymerization initiator IRGACURE 819 (manufactured by BASF) 1 part by mass, alumina ethanol sol A2K5-10 (manufactured by Kawaken Fine Chemical Co., Ltd.)
Colloidal liquid in which columnar alumina hydrate particles are dispersed in the liquid) 70 parts by mass ―――――――――――――――――――――――――――――― -

KAYARAD PET-30

[Comparative Example 1]
<Preparation of Polarizer 2>
As in the case of the polarizer 1, the composition for forming a polarizer was continuously applied onto the alignment film with a # 7 wire bar to form a coating film. Next, the coating film was heated at 140 ° C. for 90 seconds, and the coating film was cooled to room temperature (23 ° C.).
Thereafter, the polarizer 2 was formed on the alignment film by irradiating for 60 seconds under an irradiation condition of an illuminance of 28 mW / cm ² using a high-pressure mercury lamp without performing the aging step.
About the produced polarizer 2, similarly to the polarizer 1, the number of needle-like aggregates per 40 μm ² and the ratio of the needle-like aggregates having a length L of 500 nm or less were measured. As a result, the number of needle-like aggregates per 40 μm ² was 13, and the ratio of needle-like aggregates having a length L of 500 nm or less was 92.3%. FIG. 3 shows an SEM observation image of the surface of the polarizer 2.

<Formation of transparent resin layer (barrier layer)>
Using the produced polarizer 2, a transparent resin layer (barrier layer) was formed in the same manner as in the laminate 1, and a laminate 2 of Comparative Example 1 was produced.

[Comparative Example 2]
<Preparation of Polarizer 3>
As in the case of the polarizer 1, the composition 1 for forming a polarizer was continuously applied to the alignment film with a # 7 wire bar to form a coating film. Next, the coating film was heated at 140 ° C. for 90 seconds, and cooled to room temperature (23 ° C.). Next, as a maturing step, the coating film was heated at 100 ° C. for 60 seconds and cooled again to room temperature.
Thereafter, the polarizer 3 was formed on the alignment film by irradiating with a high-pressure mercury lamp under irradiation conditions of an illuminance of 28 mW / cm ² for 60 seconds.
About the produced polarizer 3, similarly to the polarizer 1, the number of needle-like aggregates per 40 μm ² and the ratio of the needle-like aggregates having a length L of 500 nm or less were measured. As a result, the number of needle-like aggregates per 40 μm ² was 72, and the ratio of needle-like aggregates having a length L of 500 nm or less was 79.2%. FIG. 4 shows an SEM observation image of the surface of the polarizer 3.

<Formation of transparent resin layer (barrier layer)>
Using the produced polarizer 3, a transparent resin layer (barrier layer) was formed in the same manner as in the laminate 1, and a laminate 3 of Comparative Example 2 was produced.

[Evaluation]
As described below, the orientation degree of the laminate having the polarizer was evaluated.

(Degree of orientation)
With the linear polarizer inserted on the light source side of an optical microscope (manufactured by Nikon, ECLIPSE E600 POL), the laminates of the examples and comparative examples were set on a sample stand, and a multi-channel spectrometer (QE65000, manufactured by Ocean Optics) was used. ), The absorbance of the light-absorbing anisotropic film in the wavelength range of 380 to 780 nm was measured at a pitch of 1 nm, and the degree of orientation at 400 to 700 nm was calculated by the following equation.
Degree of orientation: S = ((Az0 / Ay0) -1) / ((Az0 / Ay0) +2)
In the above formula, “Az0” represents the absorbance of the light absorption anisotropic film for polarized light in the direction of the absorption axis, and “Ay0” represents the absorbance of the light absorption anisotropic film for polarized light in the direction of the polarization axis.

as a result,
Example 1 (laminate 1) has a degree of orientation of 0.95;
Comparative Example 1 (laminate 2) had an orientation degree of 0.92,
The degree of orientation of Comparative Example 2 (Laminate 3) was 0.89.

Claims (3)

1. A polarizer formed from a polarizer-forming composition containing a liquid crystal compound and a dichroic substance,
   The liquid crystal compound and the dichroic substance are horizontally aligned,
   Aggregates are observed on the surface observed with a scanning electron microscope, and when the length of the major axis of the aggregate is L and the length of the minor axis is D,
   More than 15 needle-like aggregates, which are aggregates satisfying L ≧ 300 nm and L / D> 2, are observed per 40 μm ² .
   The polarizer, wherein the number of the acicular aggregates satisfying L ≦ 500 nm among the acicular aggregates is 80% or more.
2. The polarizer according to claim 1, wherein 90% or more of the needle-like aggregates have an angle formed by the alignment axis and the long axis of the liquid crystalline compound of 5 ° or more.
3. 画像 An image display device comprising the polarizer according to claim 1.

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