JP7207110B2 - Polymerizable liquid crystal composition, liquid crystal polymer and retardation film - Google Patents

Description

The present invention relates to a liquid crystal polymer obtained by polymerizing a polymerizable liquid crystal composition. In particular, the present invention relates to a liquid crystal polymer obtained by polymerizing a homogenously aligned polymerizable liquid crystal composition on a substrate subjected to photo-alignment treatment.

A liquid crystal display device is provided with a retardation film in order to widen a viewing angle, adjust an image color tone, and the like. A stretched polymer film is used as such a retardation film. A liquid crystal polymer, which is a polymer (cured product) of a polymerizable liquid crystal composition, can also be used as the retardation film. By using a liquid crystal polymer, it is expected that the thickness of the retardation film can be reduced and the durability thereof can be improved.

A retardation film using a liquid crystal polymer is produced by coating a polymerizable liquid crystal composition solution on a substrate that has been subjected to alignment treatment, orienting the polymerizable liquid crystal composition, and then polymerizing the polymerizable liquid crystal composition. (Patent Document 1).
A liquid crystal polymer with homogeneous orientation functions as an A-plate such as a half-wave plate or a quarter-wave plate.

When the liquid crystal polymer is formed on the substrate, it is required that no peeling occurs in the process of processing the retardation film or the process of manufacturing the liquid crystal display device. A polymerizable liquid crystal composition containing, as an adhesion promoter, an acrylate having a hydroxyl group, an acrylate having a cyclic ether structure, or the like has been proposed for the purpose of improving the adhesion between a substrate and a liquid crystal polymer (Patent Document 2). , 3).
Also, a method of improving adhesiveness by controlling the polymerization rate of a liquid crystal polymer has been proposed (Patent Document 4).

For the purpose of improving the display quality of a liquid crystal display device, a retardation film with high front contrast has been proposed (Patent Document 5).

In-cell retardation films, in which a retardation film is arranged inside a liquid crystal cell, have been proposed from the viewpoint of improving productivity by making the liquid crystal display device thinner, lighter, and by reducing the bonding process. The in-cell retardation film is required to have high heat resistance so that the retardation function does not change significantly even in heat treatment at around 230° C. required in the manufacturing process of liquid crystal cells (Patent Document 6).

The in-cell retardation film is also required to have high adhesion to the substrate. An in-cell retardation film with good adhesiveness has been proposed by controlling the mass ratio of a monofunctional polymerizable liquid crystal compound and a bifunctional polymerizable liquid crystal compound, which are components of a polymerizable liquid crystal composition (Patent Document 7). ).

JP 2007-148098 A Japanese Patent Publication No. 2007-506813 JP 2014-219659 A JP 2007-93864 A JP 2018-039990 A JP 2015-105986 A WO2014/073578

As the polymerizable liquid crystal compound, a methacryloyl group or an acryloyl group (hereinafter collectively referred to as a (meth)acryloyl group) is used for reasons such as ease of synthesis and high polymerization reactivity (curability). A compound having a polymerizable group is mainly used.
In the polymerization reaction, curing shrinkage occurs because van der Waals distances are converted into covalent bond distances. In particular, since the polymerization reaction of a compound having a (meth)acryloyl group is addition polymerization, curing shrinkage is large. A liquid crystal polymer comprising such a compound has a problem that the adhesiveness to the substrate tends to decrease due to the influence of internal stress due to curing shrinkage.

In order to improve the front contrast of liquid crystal polymers, uniform and highly ordered alignment is required. A liquid crystal polymer composed of a polymerizable liquid crystal composition having a (meth)acryloyl group undergoes a large curing shrinkage due to a polymerization reaction, and thus has a problem that the alignment order is lowered and the front contrast tends to be lowered.

There is a method of improving the adhesiveness between the substrate and the liquid crystal polymer by using a polymerizable liquid crystal composition containing an adhesion promoter. However, in the case of conventional adhesion promoters, there is a problem that the front contrast of the resulting liquid crystal polymer is greatly deteriorated when the polymerizable liquid crystal composition is contained in an amount capable of exhibiting sufficient adhesiveness.

The method of including a monofunctional component in the polymerizable liquid crystal composition and the method of suppressing the polymerization rate of the liquid crystal polymer are intended to improve the adhesiveness between the substrate and the liquid crystal polymer by suppressing curing shrinkage. . However, these methods have the problem that the retardation function is greatly deteriorated in a high-temperature environment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal polymer having excellent adhesion to a substrate and excellent front contrast. Another object of the present invention is to provide a liquid crystal polymer in which a change in retardation function is suppressed even in a high-temperature environment.

Embodiment 1 of the present invention is a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound (A) and an adhesion promoter (B) which is a polymerizable compound having one or more amino groups and one or more hydroxyl groups. .

Aspect 2 of the present invention is the polymerizable liquid crystal composition of Aspect 1, wherein the polymerizable liquid crystal compound (A) is a compound having two or more polymerizable groups.

Aspect 3 of the present invention is the polymerizable liquid crystal composition according to Aspect 1 or 2, wherein the adhesion promoter (B) is an amine-modified epoxy acrylate.

Aspect 4 of the present invention is the polymerization according to any one of aspects 1 to 3, wherein the content of the adhesion promoter (B) is 0.01 to 5% by weight with respect to the total amount of the polymerizable liquid crystal composition. It is a liquid crystal composition.

Aspect 5 of the present invention is the polymerizable liquid crystal composition according to any one of Aspects 1 to 4, further comprising a surfactant, a polymerization initiator and a polymerization inhibitor.

Aspect 6 of the present invention is a liquid crystal polymer having optical anisotropy obtained by polymerizing the polymerizable liquid crystal composition according to any one of aspects 1 to 5.

Aspect 7 of the present invention is the liquid crystal polymer according to aspect 6, wherein the liquid crystal molecules are fixed in a homogeneous orientation.

Aspect 8 of the present invention is the liquid crystal polymer according to aspect 6, wherein the liquid crystal molecules are fixed in a twisted orientation.

Aspect 9 of the present invention is a retardation film obtained by directly laminating a layer of the liquid crystal polymer according to any one of aspects 6 to 8 on a substrate subjected to alignment treatment.

A tenth aspect of the present invention is the retardation film according to the ninth aspect, which is directly laminated on a substrate that has been subjected to photo-alignment treatment.

Aspect 11 of the present invention is the retardation film according to Aspect 9 or 10, wherein the in-plane retardation Re(550) at a wavelength of 550 nm is 100 nm or more and 300 nm or less.

Aspect 12 of the present invention is a color filter in which the retardation film according to any one of Aspects 9 to 11 is laminated on a color filter layer directly or via a planarizing layer.

Aspect 13 of the present invention is a display device comprising the retardation film according to any one of Aspects 9 to 11.

The liquid crystal polymer obtained by the present invention has excellent adhesiveness to substrates and excellent front contrast. In addition, the liquid crystal polymer suppresses changes in the retardation function even in a high-temperature environment.

In the present invention, "adhesiveness" indicates the degree of adhesion between the liquid crystal polymer and the substrate with which the liquid crystal polymer is in direct contact. Low adhesiveness indicates that the liquid crystal polymer is easily peeled from the substrate, and high adhesiveness indicates that the liquid crystal polymer is difficult to peel off from the substrate.

In the present invention, "front contrast" is the value of (luminance in parallel Nicols state)/(luminance in crossed Nicols state) when an object is placed between two polarizing plates.
In the present invention, the “crossed Nicols state” is a state in which the polarizing axes of the polarizing plates facing each other are perpendicular to each other.
In the present invention, the “parallel Nicols state” is a state in which the polarizing axes of the polarizing plates arranged opposite to each other are aligned.

In the present invention, "Re" means retardation, which means the phase delay of extraordinary light with respect to ordinary light. A retardation function means retardation. Assuming that the thickness of the liquid crystal polymer layer is d, and Δn is the birefringence index, Re=Δn·d.

In the present invention, "Re(λ)" is the retardation when light of wavelength λ nm is vertically incident on the film surface.

In the present invention, "the number of π electrons" means the number of double bonds in the structural formula of an organic compound in which the valence electrons are localized. }×2. In addition, when oxygen and nitrogen are contained in the compound, it is calculated by the number of unshared electron pairs contained in the oxygen and nitrogen and the above-mentioned {number of double bonds in the structural formula based on the valence} x 2. It is the value obtained by adding up the number of

In the present invention, "compound (X)" means a compound represented by formula (X). Here, X in "compound (X)" is a character string, number, symbol, or the like.

In the present invention, the "liquid crystal composition" is a mixture having a liquid crystal phase.
The term "liquid crystal compound" as used in the present invention is a general term for (A) compounds having a liquid crystal phase as pure substances and (B) compounds serving as components of a liquid crystal composition.

In the present invention, a "polymerizable group" is a functional group that, when present in a compound, polymerizes by means of light, heat, catalyst, etc., and changes into a polymer having a higher molecular weight.
In the present invention, a "monofunctional compound" is a compound having one polymerizable group.
In the present invention, a "polyfunctional compound" is a compound having multiple polymerizable groups.
In the present invention, the "X functional compound" is a compound having X polymerizable groups. Here, X in "X functional compound" is an integer.
In the present invention, the "polymerizable compound" is a compound having at least one polymerizable group.
In the present invention, the “polymerizable liquid crystal compound” is a polymerizable compound that is a liquid crystal compound.
In the present invention, the “non-liquid crystal polymerizable compound” is a polymerizable compound that does not have a liquid crystal phase when pure.

In the present invention, the "polymerizable liquid crystal composition" means a composition containing a polymerizable liquid crystal compound and having a liquid crystal phase.
In the present invention, "polymerizable liquid crystal composition solution" means a mixture containing a polymerizable liquid crystal composition and a solvent.
In the present invention, "liquid crystal polymer" means a portion obtained by polymerizing a polymerizable liquid crystal composition.

In the present invention, the “retardation film” is a laminate of a liquid crystal polymer layer and a substrate subjected to alignment treatment, and is an element having optical anisotropy.
In the present invention, the term "in-cell" refers to a cell in which a liquid crystal layer is enclosed between two substrates, and refers to the liquid crystal layer side that is inside between the substrates.
In the present invention, the "in-cell retardation film" means a retardation film placed inside the liquid crystal cell.

In the present invention, "homogeneous alignment" refers to an alignment state in which the pretilt angle of liquid crystal molecules is 0 to 5 degrees.
In the present invention, the term "pretilt angle" refers to the angle at which liquid crystal molecules rise from the substrate.
In the present invention, the term "twisted alignment" means that the alignment direction of the long axis of the liquid crystal molecules is parallel to the substrate, and as it separates from the substrate, it is twisted stepwise around the normal to the substrate surface. It means the state of being.

In the present invention, "tackiness" refers to stickiness of the liquid crystal polymer. When the surface of the liquid crystal polymer is touched with a finger, the state in which the liquid crystal polymer sticks to the finger is said to have tackiness.

In the present invention, "room temperature" refers to 15°C to 35°C.

When the following chemical structure is described in the chemical formula, the wavy line indicates the bonding position of the atom or the functional group. Here, C below is any atom or functional group.

In the chemical formulas, the same symbols are used, and when there are a plurality of them, the structures indicated by the symbols may be the same or different.

Liquid crystal alignment includes homogeneous alignment, homeotropic alignment, twist alignment, splay alignment, hybrid alignment, and the like.

<<Polymerizable liquid crystal composition>>
The polymerizable liquid crystal composition of the present invention contains at least one polymerizable liquid crystal compound (A) and at least one adhesion promoter (B).

<Adhesion promoter (B)>
The adhesion promoter (B) is a polymerizable compound having one or more amino groups and one or more hydroxyl groups in its molecule. By including the adhesion promoter (B) in the polymerizable composition of the present invention, a liquid crystal polymer having improved adhesion to a substrate can be formed. In addition, having an amino group promotes the polymerization reaction, making it possible to form a liquid crystal polymer having excellent heat resistance. In addition, the adhesion promoter of the present invention can provide sufficient adhesion to the polymerizable liquid crystal composition with a small content. Therefore, the liquid crystal polymer comprising the polymerizable liquid crystal composition of the present invention has excellent front contrast. In addition, the change in the phase difference function under high temperature environment is suppressed.

The polymerizable compound serving as the adhesion promoter (B) is preferably a polyfunctional compound having two or more polymerizable groups. By having two or more polymerizable groups, deterioration of the heat resistance, water resistance, chemical resistance, etc. of the liquid crystal polymer can be suppressed.

The adhesion promoter (B) is preferably an amine-modified epoxy acrylate. Amine-modified epoxy acrylate is a compound obtained by reacting a compound (b1) having at least one epoxy group with a compound (b2) having at least one amino group and acryloyl group. The amino group contained in the amine-modified epoxy acrylate is preferably a secondary amino group or a tertiary amino group. Therefore, the amino group contained in the compound (b2) is preferably a primary amino group or a secondary amino group. Also, the amine-modified epoxy acrylate preferably contains a biphenyl skeleton and/or a bisphenol skeleton. By containing a biphenyl skeleton or a bisphenol skeleton in the amine-modified epoxy acrylate, it is possible to further suppress changes in the retardation function of the resulting liquid crystal polymer under high-temperature environments. Therefore, the compound (b1) is preferably a compound having an epoxy group containing a biphenyl skeleton and/or a bisphenol skeleton.

The content of the adhesion promoter (B) is not particularly limited as long as the effects of the present invention are not impaired. It is preferably 0.01 to 5% by weight, more preferably 0.05 to 2% by weight, even more preferably 0.1 to 1% by weight, based on the total amount of the composition.

<Polymerizable liquid crystal compound (A)>
The polymerizable liquid crystal composition of the present invention contains at least one polymerizable liquid crystal compound (A).
The polymerizable liquid crystal compound (A) is preferably a compound having two or more polymerizable groups in its molecule (a polyfunctional compound having two or more polymerizable groups). By having two or more polymerizable groups in the polymerizable liquid crystal compound (A), it is possible to suppress deterioration in heat resistance, water resistance, chemical resistance, etc. of the resulting liquid crystal polymer.
The polymerizable liquid crystal compound (A) may be either a rod-like liquid crystal compound or a discotic liquid crystal compound, but is preferably a rod-like liquid crystal compound from the viewpoint of ease of synthesis and productivity.

As the polymerizable liquid crystal compound (A), a polymerizable liquid crystal compound represented by the following formula (1) or (2) is preferable.

上記式（１）中、ｍは１、２、３、または４であり、
Ａ¹は独立して１，４－フェニレン、１，４－シクロへキシレン、１，４－シクロヘキセニレン、テトラヒドロピラン－２，５－ジイル、１，３－ジオキサン－２，５－ジイル、ナフタレン－２，６－ジイル、フルオレン－２，７－ジイル、またはインダノン－４，７－ジイルで表される二価の環であり、該二価の環おいて、少なくとも１つの水素はフッ素、塩素、トリフルオロメチル、炭素数１～１０のアルキル、炭素数２～１０のアルケニル、炭素数１～１０のアルコキシ、炭素数１～１０のアルコキシカルボニル、炭素数１～１０のアルカノイル、炭素数１～１０のアルカノイルオキシ、または重合性基を有する一価基で置き換えられてもよく、
Ｚ¹は独立して単結合、－ＯＣＨ₂－、－ＣＨ₂Ｏ－、－ＣＯＯ－、－ＯＣＯ－、－ＣＦ₂Ｏ－、－ＯＣＦ₂－、－ＣＨ₂ＣＨ₂－、－ＣＦ₂ＣＦ₂－、－ＯＣＨ₂ＣＨ₂Ｏ－、－ＣＨ＝ＣＨＣＯＯ－、－ＯＣＯＣＨ＝ＣＨ－、－ＣＨ₂ＣＨ₂ＣＯＯ－、－ＯＣＯＣＨ₂ＣＨ₂－、－ＣＨ₂ＣＨ₂ＯＣＯ－、－ＣＯＯＣＨ₂ＣＨ₂－、－ＣＨ＝ＣＨ－、－Ｎ＝ＣＨ－、－ＣＨ＝Ｎ－、－Ｎ＝Ｃ（ＣＨ₃）－、－Ｃ（ＣＨ₃）＝Ｎ－、－Ｎ＝Ｎ－、－Ｃ≡Ｃ－、－ＣＨ＝Ｎ－Ｎ＝ＣＨ－、－Ｃ（ＣＨ₃）＝Ｎ－Ｎ＝Ｃ（ＣＨ₃）－、または炭素数４～２０のアルキレンであり、該アルキレンにおいて少なくとも１つの－ＣＨ₂－は－Ｏ－で置き換えられてもよく、
Ｐ¹は独立して重合性基を有する一価基である。

In the above formula (1), m is 1, 2, 3, or 4,
A ¹ is independently 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene -2,6-diyl, fluorene-2,7-diyl, or indanone-4,7-diyl, in which at least one hydrogen is fluorine or chlorine , trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkoxycarbonyl having 1 to 10 carbon atoms, alkanoyl having 1 to 10 carbon atoms, 1 to 1 carbon atoms. 10 alkanoyloxy, or optionally substituted with a monovalent group having a polymerizable group,
Z ¹ is independently a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CF ₂ O-, -OCF ₂ -, -CH ₂ CH ₂ -, -CF ₂ CF _2- , -OCH ₂ CH ₂ O-, -CH=CHCOO-, -OCOCH=CH-, -CH ₂ CH ₂ COO-, -OCOCH ₂ CH ₂ -, -CH ₂ CH ₂ OCO-, -COOCH ₂ CH ₂ -, -CH=CH-, -N=CH-, -CH=N-, -N=C(CH ₃ )-, -C(CH ₃ )=N-, -N=N-, -C≡ C—, —CH=N—N=CH—, —C(CH ₃ )=N—N=C(CH ₃ )—, or alkylene having 4 to 20 carbon atoms, in which at least one —CH ₂ - may be replaced by -O-,
P ¹ is a monovalent group independently having a polymerizable group.

From the viewpoint of high curability (polymerization reactivity), solubility in solvents, ease of handling, etc., the monovalent group having a polymerizable group shown in formula (1) is represented by the following formula (P ¹ -1) is preferred.

上記式（Ｐ¹－１）中、Ｙ¹は単結合、－Ｏ－、－ＣＯＯ－、－ＯＣＯ－、または－ＯＣＯＯ－であり、
Ｑ¹は単結合または炭素数１～２０のアルキレンであり、該アルキレンにおいて少なくとも１つの－ＣＨ₂－は－Ｏ－、－ＣＯＯ－、または－ＯＣＯ－で置き換えられてもよく、ＰＧ¹はアクリロイルオキシ基またはメタクリロイルオキシ基である。

In the above formula (P ¹ -1), Y ¹ is a single bond, -O-, -COO-, -OCO-, or -OCOO-,
Q ¹ is a single bond or alkylene having 1 to 20 carbon atoms, in which at least one —CH ₂ — may be replaced with —O—, —COO—, or —OCO—, and PG ¹ is acryloyl It is an oxy group or a methacryloyloxy group.

上記式（２）中、ｎは独立して１または２であり、
Ａ²は独立して１，４－フェニレン、または１，４－シクロへキシレンで表される二価の環であり、該二価の環おいて、少なくとも１つの水素はフッ素、塩素、トリフルオロメチル、炭素数１～１０のアルキル、炭素数２～１０のアルケニル、炭素数１～１０のアルコキシ、炭素数１～１０のアルコキシカルボニル、炭素数１～１０のアルカノイル、炭素数１～１０のアルカノイルオキシ、または重合性基を有する一価基で置き換えられてもよく、
Ｚ²は独立して単結合、－ＯＣＨ₂－、－ＣＨ₂Ｏ－、－ＣＯＯ－、－ＯＣＯ－、－ＣＨ₂ＣＨ₂－、－ＯＣＨ₂ＣＨ₂Ｏ－、－ＣＨ₂ＣＨ₂ＣＯＯ－、－ＯＣＯＣＨ₂ＣＨ₂－、－ＣＨ₂ＣＨ₂ＯＣＯ－、または－ＣＯＯＣＨ₂ＣＨ₂－であり、
Ｐ²は独立して重合性基を有する一価基であり、
Ｇは、下記式（Ｇ－１）、（Ｇ－２）、（Ｇ－３）、または（Ｇ－４）で表される基である。

In the above formula (2), n is independently 1 or 2,
A ² is a divalent ring independently represented by 1,4-phenylene or 1,4-cyclohexylene, in which at least one hydrogen is fluorine, chlorine or trifluoro methyl, alkyl having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkoxycarbonyl having 1 to 10 carbon atoms, alkanoyl having 1 to 10 carbon atoms, alkanoyl having 1 to 10 carbon atoms oxy, or may be substituted with a monovalent group bearing a polymerizable group,
Z ² is independently a single bond, -OCH ₂ -, -CH ₂ O-, -COO-, -OCO-, -CH ₂ CH ₂ -, -OCH ₂ CH ₂ O-, -CH ₂ CH ₂ COO- , -OCOCH ₂ CH ₂ -, -CH ₂ CH ₂ OCO-, or -COOCH ₂ CH ₂ -,
^P2 is a monovalent group independently having a polymerizable group;
G is a group represented by the following formula (G-1), (G-2), (G-3), or (G-4).

上記式（Ｇ－１）～（Ｇ－４）中、
Ｘ¹は独立して－ＣＨ₂－、－ＮＨ－、－Ｏ－、－Ｓ－、または－ＣＯ－であり、－ＣＨ₂－または－ＮＨ－において、少なくとも１つの水素は炭素数１～５のアルキルで置き換えられてもよく、
－Ｘ²＝は独立して－ＣＨ＝または－Ｎ＝であり、
Ｚ³は独立して単結合、－ＣＨ＝ＣＨ－、－Ｃ≡Ｃ－、－ＣＨ＝Ｎ－、－Ｎ＝ＣＨ－、－ＣＨ＝Ｎ－ＮＲ¹－、－Ｃ（ＣＨ₃）＝Ｎ－ＮＲ¹－または－ＣＨ＝Ｎ－Ｎ＝ＣＨ－であり、ここで、Ｒ¹は独立して水素、炭素数１～１０のアルキルまたは重合性基を有する一価基であり、
Ｔ¹、Ｔ⁴およびＴ⁵はそれぞれπ電子の数が６～１４である１価基であり、
Ｔ²、Ｔ³およびＴ⁶はそれぞれ独立して、水素、トリフルオロメチル、シアノ、炭素数１～５のアルキル、炭素数２～５のアルケニル、炭素数１～５のアルコキシ、炭素数１～５のアルコキシカルボニル、炭素数１～５のアルカノイル、炭素数１～５のアルカノイルオキシ、炭素数１～５のアルキルスルフィド、または重合性基を有する一価基であり、
Ｔ²およびＴ³は、上記一価基に代えて、これらが一体となって、酸素原子、窒素原子、または硫黄原子を含む、５～７員環の、複素環または環状ケトンであってもよい。

In the above formulas (G-1) to (G-4),
X ¹ is independently -CH ₂ -, -NH-, -O-, -S-, or -CO-, and in -CH ₂ - or -NH-, at least one hydrogen has 1 to 5 carbon atoms; may be substituted with an alkyl of
-X ² = is independently -CH= or -N=,
Z ³ is independently a single bond, -CH=CH-, -C≡C-, -CH=N-, -N=CH-, -CH=N-NR ¹ -, -C(CH ₃ )=N -NR ¹ - or -CH=N-N=CH-, where R ¹ is independently hydrogen, alkyl having 1 to 10 carbon atoms, or a monovalent group having a polymerizable group;
T ¹ , T ⁴ and T ⁵ are each a monovalent group having 6 to 14 π electrons,
T ² , T ³ and T ⁶ are each independently hydrogen, trifluoromethyl, cyano, alkyl having 1 to 5 carbon atoms, alkenyl having 2 to 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, and alkoxy having 1 to 5 carbon atoms. 5 alkoxycarbonyl, alkanoyl having 1 to 5 carbon atoms, alkanoyloxy having 1 to 5 carbon atoms, alkylsulfide having 1 to 5 carbon atoms, or a monovalent group having a polymerizable group,
T ² and T ³ may be a 5- to 7-membered heterocyclic ring or cyclic ketone containing an oxygen atom, a nitrogen atom, or a sulfur atom, in place of the above monovalent groups. good.

From the viewpoint of high curability (polymerization reactivity), solubility in solvents, ease of handling, etc., the monovalent group having a polymerizable group shown in formula (2) is represented by the following formula (P ² -1) is preferred.

上記式（Ｐ²－１）において、Ｙ²は単結合、－Ｏ－、－ＣＯＯ－、－ＯＣＯ－、または－ＯＣＯＯ－であり、
Ｑ²は単結合または炭素数１～２０のアルキレンであり、該アルキレンにおいて少なくとも１つの－ＣＨ₂－は－Ｏ－、－ＣＯＯ－、または－ＯＣＯ－で置き換えられてもよく、ＰＧ²はアクリロイルオキシ基またはメタクリロイルオキシ基である。

In the above formula (P ² -1), Y ² is a single bond, -O-, -COO-, -OCO-, or -OCOO-,
Q ² is a single bond or alkylene having 1 to 20 carbon atoms, in which at least one —CH ₂ — may be replaced with —O—, —COO—, or —OCO—, and PG ² is acryloyl It is an oxy group or a methacryloyloxy group.

Examples of the polymerizable liquid crystal compound (A) represented by the above formula (1) include compounds represented by the following formulas (1-1) to (1-20).

In the above formulas (1-1) to (1-20), Y ¹ is independently a single bond, -O-, -COO-, -OCO-, or -OCOO-,
Q ¹ is independently a single bond or an alkylene having 1 to 20 carbon atoms, in which at least one —CH ₂ — may be replaced with —O—, —COO—, or —OCO—;
PG ¹ is independently an acryloyloxy group or a methacryloyloxy group.

Examples of the polymerizable liquid crystal compound (A) represented by the above formula (2) include the following formulas (2-1-1) to (2-1-5), formulas (2-2-1) to (2 -2-6), formulas (2-3-1) to (2-3-6), and compounds represented by formulas (2-4-1) to (2-4-5).

The above formulas (2-1-1) to (2-1-5), formulas (2-2-1) to (2-2-6), formulas (2-3-1) to (2-3-6 ), and in formulas (2-4-1) to (2-4-5), Y is independently a ^single bond, —O—, —COO—, —OCO—, or —OCOO—;
Q ² is independently a single bond or an alkylene having 1 to 20 carbon atoms, in which at least one —CH ₂ — may be replaced with —O—, —COO—, or —OCO—;
PG ² is independently acryloyloxy or methacryloyloxy.

<Other ingredients>
The polymerizable liquid crystal composition of the present invention may contain components other than the polymerizable liquid crystal compound (A) and the adhesion promoter (B) as long as they do not impair the expression of the liquid crystal phase of the resulting polymerizable liquid crystal composition. .

[Curing accelerator]
The polymerizable liquid crystal composition of the invention may contain a curing accelerator. The curing accelerator as used in the present invention is a polymerizable compound having three or more polymerizable groups and no amino group in its molecule. By incorporating a curing accelerator into the polymerizable liquid crystal composition, a liquid crystal polymer having a surface with high mechanical strength and chemical resistance can be obtained.

Examples of the curing accelerator include pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylol EO addition triacrylate, trisacryloyloxyethyl phosphate, tris(acryloyloxyethyl) isocyanurate, alkyl-modified dipentaerythritol triacrylate, Acrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, alkyl-modified dipentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypenta Acrylates, alkyl-modified dipentaerythritol pentaacrylate, pentaerythritol trimethacrylate, trimethylolpropane trimethacrylate, trimethylol EO addition trimethacrylate, tris methacryloyloxyethyl phosphate, tris methacryloyloxyethyl isocyanurate, alkyl-modified dipentaerythritol trimethacrylate , EO-modified trimethylolpropane trimethacrylate, PO-modified trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, alkyl-modified dipentaerythritol tetramethacrylate, ditrimethylolpropane tetramethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol monohydroxypentamethacrylate , alkyl-modified dipentaerythritol pentamethacrylate, and the like.

The content of the curing accelerator in the polymerizable liquid crystal composition is preferably 0.1 to 10% by weight, more preferably 0.1 to 5% by weight, and 0.5% by weight, based on the total amount of the polymerizable liquid crystal composition. ~5% by weight is more preferred. If the content of the curing accelerator is less than the above lower limit, it may be difficult to form a liquid crystal polymer with high mechanical strength. If the content of the curing accelerator exceeds the above upper limit, the adhesiveness to the substrate and the optical properties may deteriorate.

[Surfactant]
The polymerizable liquid crystal composition of the invention may contain a surfactant. By incorporating a surfactant into the polymerizable liquid crystal composition, a liquid crystal polymer (for example, a liquid crystal polymer layer) with improved smoothness can be obtained. Surfactants are classified into ionic surfactants and nonionic surfactants.
Since a liquid crystal polymer (for example, a liquid crystal polymer layer) with improved smoothness can be obtained, and because it has the effect of suppressing the tilt alignment on the air interface side of the liquid crystal polymer film, a nonionic surfactant is preferred.
Examples of nonionic surfactants include silicone-based nonionic surfactants, fluorine-based nonionic surfactants, vinyl-based nonionic surfactants, and hydrocarbon-based nonionic surfactants. be done.

Examples of silicone-based nonionic surfactants include compounds that are linear polymers composed of siloxane bonds and have organic groups such as polyethers and long-chain alkyls introduced into side chains and/or terminals. .

Examples of fluorine-based nonionic surfactants include compounds having a perfluoroalkyl group or a perfluoroalkenyl group having 2 to 7 carbon atoms.

Examples of vinyl-based nonionic surfactants include (meth)acrylic polymers having a weight average molecular weight of 1,000 to 1,000,000.

A surfactant having a polymerizable group may be used as the surfactant in order to improve the mechanical strength and chemical resistance of the surface of the resulting liquid crystal polymer (eg, liquid crystal polymer layer). As the surfactant having a polymerizable group, a surfactant that initiates polymerization by ultraviolet rays is preferred.

The resulting liquid crystal polymer (e.g., liquid crystal polymer layer) tends to be uniformly oriented, and the coatability of the polymerizable liquid crystal composition is improved. It is preferably 0.01 to 5% by weight, more preferably 0.05 to 1% by weight, based on the total amount of the product.

[Polymerization initiator]
The polymerizable liquid crystal composition of the invention may contain a polymerization initiator. By including a polymerization initiator in the polymerizable liquid crystal composition, the polymerization speed (curing speed) of the polymerizable liquid crystal composition can be optimized. The polymerization initiator is preferably a photopolymerization initiator, more preferably a radical photopolymerization initiator, because of the ease of the curing process.

Examples of the photoradical polymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2,2-dimethoxy -1,2-diphenylethan-1-one, p-methoxyphenyl-2,4-bis(trichloromethyl)triazine, 2-(p-butoxystyryl)-5-trichloromethyl-1,3,4-oxazide Azole, 9-phenylacridine, 9,10-benzphenazine, benzophenone/Michler's ketone mixture, hexaarylbiimidazole/mercaptobenzimidazole mixture, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one , benzyl dimethyl ketal, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4-diethylxanthone/methyl p-dimethylaminobenzoate mixture, benzophenone/methyltriethanol Amine Mixtures, ADEKA OPTOMER N-1919, ADEKA CRUSE NCI-831, ADEKA CRUSE NCI-930, OMNIRAD 127, OMNIRAD 184, OMNIRAD 369, OMNIRAD 379, OMNIRAD 500, OMNIRAD 651, OMNIRAD 754, OMNIRAD 819, OMNIRAD 907, OMNIRAD 1173, Omnilad 2022, Omnilad 2100, Omnilad 2959, Omnilad 4265, Irgacure OXE01, Irgacure OXE02, Omnilad MBF, Omnilad TPO, and the like. Adeka Optomer, Adeka Cruz, Omnilad and Irgacure are registered trademarks herein.

From the viewpoint of improving the front contrast of the obtained liquid crystal polymer, preventing tackiness, and preventing the optical properties from changing with time, the above polymerization initiator (typically a photopolymerization initiator) in the polymerizable liquid crystal composition is added. is preferably 1 to 30% by weight, more preferably 1 to 15% by weight, still more preferably 3 to 10% by weight, based on the total weight of the polymerizable liquid crystal composition.

When a photopolymerization initiator is contained in the polymerizable liquid crystal composition, a sensitizer may be contained in the polymerizable liquid crystal composition together with the photopolymerization initiator. Examples of the sensitizer include isopropylthioxanthone, diethylthioxanthone, ethyl-4dimethylaminobenzoate, and 2-ethylhexyl-4-dimethylaminobenzoate.

The polymerizable liquid crystal composition of the invention may contain a chain transfer agent. By including a chain transfer agent in the polymerizable liquid crystal composition, the reaction rate of the polymerizable liquid crystal compound and the length of the polymer chain of the liquid crystal polymer (eg, liquid crystal polymer layer) can be adjusted. As the content of the chain transfer agent increases, the reaction rate of the polymerizable liquid crystal compound tends to decrease. As the chain transfer agent content increases, the polymer chain length tends to decrease.

Examples of the chain transfer agent include monofunctional or polyfunctional thiol derivatives, styrene dimer derivatives and the like.

Examples of the monofunctional thiol derivative include dodecanethiol and 2-ethylhexyl-(3-mercapto)propionate.
Examples of the polyfunctional thiol derivative include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), 1,4-bis(3-mercaptobutyryloxy)butane, Pentaerythritol tetrakis(3-mercaptobutyrate), 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, etc. is mentioned.
Examples of the styrene dimer chain transfer agent include 2,4-diphenyl-4-methyl-1-pentene and 2,4-diphenyl-1-butene.

[Polymerization inhibitor]
The polymerizable liquid crystal composition of the invention may contain a polymerization inhibitor. By including a polymerization inhibitor in the polymerizable liquid crystal composition, the initiation of polymerization during storage of the polymerizable liquid crystal composition and the polymerizable liquid crystal composition solution can be suppressed, so that the storage stability of the polymerizable liquid crystal composition can be improved. . Moreover, the oxidation of the obtained liquid crystal polymer can be suppressed. Furthermore, the weather resistance of the resulting liquid crystal polymer can be improved.

As the polymerization inhibitor, an antioxidant is preferable. Examples of antioxidants that can be used as polymerization inhibitors include phenol antioxidants, sulfur antioxidants, phosphoric acid antioxidants, hindered amine antioxidants, and the like. Among these, phenolic antioxidants are preferred from the viewpoint of compatibility with the polymerizable liquid crystal composition and transparency of the obtained liquid crystal polymer (for example, liquid crystal polymer layer). Among phenolic antioxidants, phenolic antioxidants having a t-butyl group at the ortho-position to the hydroxyl group bonded to the benzene ring are preferred from the viewpoint of compatibility.

The content of the polymerization inhibitor in the polymerizable liquid crystal composition is 0.00% relative to the total amount of the polymerizable liquid crystal composition, from the viewpoints of improving storage stability, preventing stickiness, and preventing changes in optical properties over time. 01 to 5% by weight is preferred, and 0.01 to 0.5% by weight is more preferred. When two or more polymerization inhibitors are contained in the polymerizable liquid crystal composition, the total amount of these polymerization inhibitors is preferably within the above range.

The polymerizable liquid crystal composition of the present invention may contain ultraviolet absorbers, light stabilizers, silane coupling agents, etc., in addition to the other components described above.
By including an ultraviolet absorber in the polymerizable liquid crystal composition, the weather resistance of the polymerizable liquid crystal composition can be improved.
By including a light stabilizer in the polymerizable liquid crystal composition, the weather resistance of the polymerizable liquid crystal composition can be improved.
By including a silane coupling agent in the polymerizable liquid crystal composition, the adhesion between the resulting liquid crystal polymer (liquid crystal polymer layer) and the substrate can be improved.

<<Polymerizable liquid crystal composition solution>>
A solvent is preferably added to the polymerizable liquid crystal composition in order to facilitate application to a substrate (typically, a substrate subjected to alignment treatment).
From the viewpoint of compatibility between the polymerizable liquid crystal compound and the solvent, the content of the polymerizable liquid crystal composition in the polymerizable liquid crystal composition solution is preferably 5 to 50% by weight, more preferably 15 to 40% by weight.
Examples of the solvent include ester solvents, amide solvents, alcohol solvents, ether solvents, cyclic ether solvents, aromatic hydrocarbon solvents, halogenated aromatic hydrocarbon solvents, and aliphatic hydrocarbon solvents. , halogenated aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, ketone solvents, acetate solvents and the like.

An ester-based solvent refers to a solvent composed of a compound having an ester bond. Examples of ester solvents include alkyl acetate, ethyl trifluoroacetate, alkyl propionate, alkyl butyrate, dialkyl malonate, alkyl glycolate, alkyl lactate, monoacetin, γ-butyrolactone, γ-valerolactone and the like.

Examples of the alkyl acetate include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, 3-methoxybutyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate and the like.
Examples of the alkyl propionate include methyl propionate, methyl 3-methoxypropionate, ethyl propionate, propyl propionate, and butyl propionate.
Examples of the alkyl butyrate include methyl butyrate, ethyl butyrate, butyl butyrate, isobutyl butyrate, and propyl butyrate.
Examples of the alkyl malonate include diethyl malonate.
Examples of the alkyl glycolate include methyl glycolate and ethyl glycolate.
Examples of the alkyl lactate include methyl lactate, ethyl lactate, isopropyl lactate, n-propyl lactate, butyl lactate, and ethylhexyl lactate.

An amide-based solvent refers to a solvent composed of a compound having an amide bond.
Examples of amide solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N-methylpropionamide, N,N-dimethylformamide, N,N-diethylformamide, N,N-diethylacetamide, N,N-dimethylacetamide dimethylacetal, N-methylcaprolactam, 1,3-dimethyl-2-imidazolidinone and the like.

An alcoholic solvent refers to a solvent composed of a compound having a hydroxyl group.
Examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, t-butyl alcohol, sec-butyl alcohol, butanol, 3-methoxybutanol, and 2-ethylbutanol. , n-hexanol, n-heptanol, n-octanol, 1-dodecanol, ethylhexanol, 3,5,5-trimethylhexanol, n-amyl alcohol, hexafluoro-2-propanol, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, hexylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2 ,4-pentanediol, 2,5-hexanediol, 3-methyl-3-methoxybutanol, cyclohexanol, methylcyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether , diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono Propyl ether, dipropylene glycol monobutyl ether, terpineol, dihydroterpineol and the like.

An ether solvent refers to a solvent composed of a compound having an ether bond.
Examples of the ether solvent include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, bis(2-propyl) ether, diethylene glycol methyl ethyl ether, and dipropylene glycol. dimethyl ether, anisole, cyclopentyl methyl ether, methyl t-butyl ether and the like.

A cyclic ether solvent refers to a solvent composed of a cyclic compound having an ether bond.
Examples of the cyclic ether solvent include 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran and the like.

An aromatic hydrocarbon-based solvent refers to a solvent composed of a compound having an aromatic hydrocarbon.
Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, mesitylene, ethylbenzene, diethylbenzene, i-propylbenzene, n-propylbenzene, t-butylbenzene, s-butylbenzene, n-butylbenzene, tetralin. etc.

Halogenated aromatic hydrocarbon solvents include, for example, chlorobenzene and 1,2-dichlorobenzene.

Examples of aliphatic hydrocarbon solvents include hexane, heptane, and myrcene.
Halogenated aliphatic hydrocarbon solvents include, for example, chloroform, dichloromethane, carbon tetrachloride, dichloroethane, trichlorethylene, tetrachlorethylene and the like.

Alicyclic hydrocarbon solvents include, for example, cyclohexane, cycloheptane, decalin, α-pinene, β-pinene, D-limonene and the like.

A ketone-based solvent refers to a solvent composed of a compound having a ketone structure.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, and methyl propyl ketone.

An acetate-based solvent refers to a solvent composed of a compound having an acetoxy group.
Examples of the acetate solvent include ethylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, methyl acetoacetate, 1-methoxy-2-propyl acetate and the like.

The liquid crystal polymer of the present invention is obtained by polymerizing the polymerizable liquid crystal composition of the present invention described above. The liquid crystal polymer of the present invention has optical anisotropy. In one preferred embodiment of the liquid crystal polymer of the present invention, the liquid crystal molecules are fixed in a homogeneously aligned state. In another preferred embodiment, the liquid crystal polymer of the present invention is immobilized in a state of twisted alignment of liquid crystal molecules.

≪Liquid crystal polymer≫
The liquid crystal polymer of the present invention is produced, for example, by a method including the following steps (I) to (III).
(I) A polymerizable liquid crystal composition solution is applied onto a substrate (for example, an alignment-treated substrate).
(II) The solvent is removed from the polymerizable liquid crystal composition solution on the substrate by heating or other methods, and a coating film of the polymerizable liquid crystal composition is formed on the substrate.
(III) A coating film made of a polymerizable liquid crystal composition on a substrate is polymerized to produce a liquid crystal polymer on the substrate.

Various coating methods are used for coating the polymerizable liquid crystal composition solution in the step (I). From the viewpoint of the uniformity of the film thickness of the polymerizable liquid crystal composition on the substrate, among the coating methods, spin coating, micro gravure coating, gravure coating, wire bar coating, dip coating, spray coating, slit coating, etc. A coating method, a die coating method and an inkjet coating method are preferred.

As a method for removing the solvent from the polymerizable liquid crystal composition solution in the step (II), a heat treatment method is preferable. For example, when forming a film of a liquid crystal polymer on a substrate that has undergone alignment treatment, it is desirable to perform this heat treatment during drying. The heat treatment can be performed, for example, by heating on a hot plate, heating in a drying oven, blowing warm air or hot air, and the like. The temperature range of the heat treatment is preferably 40°C to 150°C, more preferably 50°C to 120°C.
Other examples of methods for removing the solvent from the polymerizable liquid crystal composition solution include decompression treatment.

In the above step (III), when producing the liquid crystal polymer of the present invention from the polymerizable liquid crystal composition of the present invention, it is desirable to align the composition before polymerization.

The polymerization of the polymerizable liquid crystal composition in step (III) can be carried out, for example, by irradiation with radiation such as electron beams, ultraviolet rays, visible rays, and infrared rays. Among these radiations, visible rays and ultraviolet rays are preferable, and ultraviolet rays are more preferable. When polymerization is performed by visible light irradiation or ultraviolet irradiation, the wavelength range of the light source used is preferably 150 to 500 nm, more preferably 250 to 450 nm, and even more preferably 300 to 400 nm.

Examples of the light source include low-pressure mercury lamps, high-pressure discharge lamps, and short arc discharge lamps. Low-pressure mercury lamps include, for example, germicidal lamps, fluorescent chemical lamps, and black lights. High-pressure discharge lamps include, for example, high-pressure mercury lamps and metal halide lamps. Short arc discharge lamps include, for example, ultra-high pressure mercury lamps, xenon lamps, and mercury-xenon lamps.

As a manufacturing process of the liquid crystal polymer of the present invention, a heating process may be included after the above process (III). By having the heating step, it is possible to improve the heat resistance, water resistance, chemical resistance and mechanical strength of the liquid crystal polymer. The temperature range of the heating step is preferably 120°C to 250°C, more preferably 150°C to 230°C.

When the liquid crystal polymer of the present invention is used as a member of a liquid crystal display element (for example, a retardation film to be described later), the liquid crystal polymer of the present invention can be arranged inside or outside the liquid crystal cell of the liquid crystal display element. The liquid crystal polymer of the present invention can be placed inside a liquid crystal cell because the optical properties of the liquid crystal polymer are less affected by heat history and the elution of impurities from the liquid crystal polymer into the liquid crystal is less.

≪Phase contrast film≫
The retardation film of the present invention is a laminate of a liquid crystal polymer layer and an orientation-treated substrate. As the retardation film of the present invention, it is preferable that a layer of a liquid crystal polymer is directly laminated on a substrate subjected to an orientation treatment.

<Substrate with orientation treatment>
The substrate subjected to the alignment treatment is a substrate on which a surface treatment is performed and a structure for inducing the alignment of the liquid crystal polymer film is formed. Examples of surface treatment include rubbing treatment and photo-alignment treatment. The photo-alignment treatment is a treatment in which a substrate coated with a polymer film is irradiated with polarized ultraviolet rays.

For example, a substrate that has undergone an orientation treatment by rubbing can be obtained by the procedures including (1a) to (5a) below.
(1a) A coating film is formed on a substrate by applying a solution of an alignment agent to the substrate.
(2a) Heat treatment is performed on the obtained substrate having the coating film.
(3a) Prepare a metal roll wrapped with a rubbing cloth made of a material such as rayon, cotton, or polyamide.
(4a) A metal roll wrapped with a rubbing cloth is brought into contact with the coated surface of the substrate.
(5a) While the metal roll around which the rubbing cloth is wound is in contact with the coating film, the roll is moved in parallel with the surface of the substrate while the roll is rotated, or the substrate is moved while the roll is fixed. Let
Examples of the alignment agent include solutions containing polyimide, polyamic acid, or polyvinyl alcohol.

For example, a substrate subjected to photo-alignment treatment can be obtained by the procedures including (1b) to (3b) below.
(1b) applying a photo-alignment agent containing a solvent to the substrate;
(2b) removing the solvent from the coating of the photo-alignment agent on the substrate by heating or other methods to form a coating film of the photo-alignment agent on the substrate;
(3b) The coating film on the substrate is irradiated with linearly polarized light having a wavelength of 250 to 400 nm.

After the procedures (1b) to (3b), (4b) heat treatment may be further performed as necessary.

The photo-alignment agent contains at least one polymer containing a photosensitive group. Polymer backbones of polymers containing photosensitive groups include, for example, polyimides, polyamic acids, cycloolefin polymers, and polyacrylates. Examples of photosensitive groups contained in the polymer include chalcone, cinnamoyl, cinnamylidene, stilbene, cyclobutane, and azobenzene.

Since the photo-alignment treatment is a non-contact alignment treatment, it has excellent characteristics such as no scratches on the surface of the substrate, less dust generation and static electricity, and high alignment uniformity. From the viewpoint of high contrast, a substrate subjected to photo-alignment treatment is preferable as the substrate subjected to alignment treatment for use in the retardation film of the present invention. From the viewpoint of alignment uniformity, the retardation film of the present invention is preferably a retardation film in which a layer of the liquid crystal polymer of the present invention is directly laminated on a substrate that has undergone the photo-alignment treatment.

The retardation film of the present invention is preferably a liquid crystal polymer in which liquid crystal molecules are fixed in a homogeneous orientation. Moreover, it is preferable that the liquid crystal polymer is a liquid crystal polymer in which the liquid crystal molecules are fixed in a twisted orientation.

The retardation film of the present invention needs to be set to have an appropriate retardation in order to widen the viewing angle and improve the contrast of the display device. The in-plane retardation Re(550) of the retardation film is preferably 100 nm≦Re(550)≦300 nm.

The retardation film of the present invention is suitable as an in-cell retardation film because it has a high heat resistance in which the optical properties do not change significantly even in the heat treatment at around 230° C. required in the manufacturing process of liquid crystal cells. is.

The retardation film of the present invention can be used as a color filter by laminating it directly on a color filter layer or by laminating it via a flattening layer. The color filter is composed of a black matrix and at least RGB three-color pixel portions. The planarizing layer is an overcoat.

The retardation film of the present invention can be used for display elements. Examples of display elements include liquid crystal display elements and organic EL display elements.

The invention is explained in more detail below with reference to the examples, but is not limited to these published examples.

In the examples of the present invention, "Omn-907" is Omnilad(TM) 907 manufactured by IGM Japan LLC. Omn-907 is a photoradical polymerization initiator (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one).
In the examples of the present invention, "IRGANOX 1076" is IRGANOX (trademark) 1076 manufactured by BASF Japan. IRGANOX 1076 is a phenolic antioxidant (octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate) with a t-butyl group ortho to the hydroxyl group attached to the benzene ring. .
In the examples of the present invention, “NCI-930” is ADEKA CRUISE™ NCI-930 manufactured by ADEKA Corporation. NCI-930 is a photoradical polymerization initiator.
In the examples of the present invention, “FTX-218” is Futergent™ FTX-218 manufactured by Neos Corporation. FTX-218 is a nonionic surfactant.
In the examples of the present invention, "TF370" is TEGOFlow™ 370 from Evonik Japan. TF370 is a vinyl nonionic surfactant.
In the examples of the present invention, "F556" is DIC's Megafac™ F556. F556 is a fluorine-based nonionic surfactant.
In the examples of the present invention, "EB3703" is EBECRYL™ 3703 from Daicel Allnex. EB3703 is a polymerizable compound (amine-modified epoxy acrylate) having an amino group and one or more hydroxyl groups.
In the examples of the present invention, "HEA" is hydroxyethyl acrylate from Osaka Organic Chemical Co., Ltd. HEA is a polymerizable compound that has one or more hydroxyl groups but no amino groups.
In the examples of the present invention, "EE3000A" is Kyoeisha Chemical Co., Ltd.'s Epoxy Ester™ 3000A. EE3000A is a polymerizable compound (bisphenol A diglycidyl ether acrylic acid adduct) having one or more hydroxyl groups but no amino groups.
In the examples of the present invention, "NK-380" is Polyment (trademark) NK-380 of Nippon Shokubai Co., Ltd. NK-380 is a polymer (aminoethylated acrylic polymer) that has one or more amino groups but no hydroxyl groups.

In the examples of the present invention, "PGMEA" is propylene glycol monomethyl ether acetate.
In the examples of the present invention, "NMP" is N-methyl-2-pyrrolidone.
In an embodiment of the invention, "BC" is ethylene glycol monobutyl ether.
In the examples of the present invention, "IPA" is 2-propanol.

In the examples of the present invention, the "wire grid polarizer" is UVT300A manufactured by Polatechno.
In the examples of the present invention, the "ultra-high pressure mercury lamp" is Multilight USH-250BY manufactured by Ushio Inc.

In the examples of the present invention, "polystyrene of known molecular weight" is TSKgel standard polystyrene manufactured by Tosoh Corporation.
In the examples of the present invention, a "gel permeation chromatograph" is a system consisting of a Waters 2695 separation module and a Waters 2414 differential refractometer.
In the examples of the present invention, the "gel permeation chromatographic column" is a Shodex™ GF-7M HQ.
In the examples of the present invention, the "ellipsometer" is an OPIPRO ellipsometer manufactured by Shintech.
In an embodiment of the present invention, the "365 photodetector" is a Ushio UVD-S365 connected to a Ushio UIT-150-A.

In the examples of the present invention, the polarizing microscope is ECLIPSE E600 POL manufactured by Nikon Corporation.
In the examples of the present invention, the "luminance meter" is a YOKOGAWA 3298F.

<Measurement of weight average molecular weight>
The weight average molecular weight was determined using gel permeation chromatography using polystyrene with a known molecular weight as a standard. The temperature of the column during the development was set at 50°C. A phosphoric acid-NMP mixed solution was used as a developing solvent for gel permeation chromatography. The weight ratio of the phosphoric acid-NMP mixed solution was 0.6/100.

Measurement of optical properties, etc. <Measurement using an ellipsometer>
The retardation of the retardation film was measured with an ellipsometer at a light incident angle of 0°.
<Determination of Homogeneous Orientation>
Using an ellipsometer, the retardation was measured by changing the incident angle of light on the surface of the liquid crystal polymer film from -50° to 50° in 5° steps. Here, the tilt direction of the incident angle of light is the same as the slow axis of the liquid crystal polymer film. When both of the following conditions were satisfied, the liquid crystal polymer film was considered to be homogeneously oriented.
(a) When the retardation with respect to the incident angle of the liquid crystal polymer film is convex upward, and (b) when the absolute value of the incident angle is the same, the difference between the measured values of Re is 5%. if within

<Measurement of Luminance in Crossed Nicols State>
The luminance in the crossed Nicols state was measured by the following procedure.
(1) A retardation film was sandwiched between two polarizing plates and placed under a polarizing microscope so that both polarizing plates were in crossed Nicols.
(2) Light passing through the retardation film and two polarizing plates was evaluated using a luminance meter.
(3) The minimum luminance when the retardation film was rotated horizontally was defined as "luminance in the crossed Nicols state."

<Measurement of Luminance in Parallel Nicols State>
The luminance in the parallel Nicols state was measured by the following procedure.
(1) The retardation film was sandwiched between two polarizing plates, and placed under a polarizing microscope so that the two polarizing plates were parallel Nicols.
(2) Light passing through the retardation film and two polarizing plates was evaluated using a luminance meter.
(3) The maximum luminance when the retardation film was rotated horizontally was defined as "luminance in parallel Nicols state".

<Measurement of Front Contrast of Retardation Film>
The front contrast of the retardation film was calculated by "luminance in parallel Nicol state"/"luminance in cross Nicol state".

<Measurement of adhesion>
It was measured according to the method of JIS standard "JIS K 5600-5-6 adhesion (cross-cut method)". That is, using a cutter, a grid of 25 squares of 1 mm square is cut, a cellophane adhesive tape is attached so as not to contain air, and the cellophane adhesive tape is peeled off at once to create a grid of 25 squares. The number of squares in which peeling occurred inside was confirmed. A square in which 10% or more of each square was peeled off was defined as a square with peeling. Here, the cellophane adhesive tape is Cellotape (trademark) No. 1 manufactured by Nichiban Co., Ltd. 405 was used.

<Measurement of pencil hardness>
It was measured according to the method of JIS standard "JIS K 5600-5-4 scratch hardness (pencil method)". That is, using a pencil hardness tester (C-221 manufactured by Yoshimitsu Seiki Co., Ltd.), by scratching with the lead of a pencil (Mitsubishi Pencil Co., Ltd. Uni) fixed at an angle of 45 °, the hardness of the lead of the pencil when scratches occur It was measured.

<Method for preparing liquid crystal polymer layer>
The liquid crystal polymer layer was produced by the following procedure.
(1) The polymerizable liquid crystal composition solution was spin-coated on the alignment-treated substrate to prepare a coating film.
(2) Heating with a hot plate at 60-80° C. for 1-5 minutes to remove the solvent from the coating film.
(3) A layer of liquid crystal polymer was produced by irradiating UV rays of a constant output at room temperature from a direction of 90° to the coating film that had undergone step (2) on the alignment-treated surface. Here, the ultraviolet irradiation is carried out using a 365 photodetector so that the exposure amount of linear ultraviolet rays on the surface of the coating film on the orientation-treated surface is 500 mJ/cm ² , and the irradiation time is from 5 seconds. Adjusted for 40 seconds.

<Fabrication of Substrate Aligned by Rubbing>
A substrate (RAF-1) subjected to orientation treatment by rubbing treatment was produced by the following procedure.
(1) PIA-5370 was spin-coated on a glass substrate to prepare a coated glass substrate.
(2) The glass substrate with a coating film that has undergone procedure (1) is placed so that the surface on which the coating film is not formed is in contact with a hot plate at 80 ° C., and left to stand in that state for 1 minute. Solvent was removed.
(3) The glass substrate with the coating film after step (2) was baked in an oven at 220°C for 30 minutes.
(4) The coating film portion of the glass substrate that had undergone procedure (3) was rubbed in one direction with a rayon cloth to prepare a substrate (RAF-1) that had undergone orientation treatment by rubbing.
Here, "PIA-5370" is an alignment film Rikuson Aligner (registered trademark) PIA-5370 manufactured by JNC. PIA-5370 is an alignment agent for rubbing treatment.

<Preparation of polyamic acid solution>
[Example 1]
A polyamic acid solution was synthesized in the same manner as described in JP-A-2012-193167.
The structures of the diamines and tetracarboxylic dianhydrides used are shown below.

化合物（ＤＡ－１）、化合物（ＤＡ－２）、化合物（ＤＡ－３）および化合物（ＤＡ－４）は市販品を使用した。

Compound (DA-1), compound (DA-2), compound (DA-3) and compound (DA-4) were commercially available products.

化合物（ＡＡ－２）および化合物（ＡＡ－３）は市販品を使用した。化合物（ＡＡ－１）は国際公開２０１５／１０８１７０号の実施例に従い合成した。化合物（ＡＡ－４）は、国際公開２０１０／１５０６９３号の実施例１ ＜化合物（ＶＩＩ－４－１）の合成＞の記載に従い合成した。

Compound (AA-2) and compound (AA-3) were commercially available products. Compound (AA-1) was synthesized according to the examples of WO2015/108170. Compound (AA-4) was synthesized according to the description of Example 1 <Synthesis of compound (VII-4-1)> in WO2010/150693.

0.90 g of diamine (DA-1), 0.06 g of diamine (DA-3) and 17 ml of NMP were added and dissolved by stirring under a nitrogen stream. Then, 1.8 g of tetracarboxylic dianhydride (AA-4) and 10 ml of NMP were added and stirred at room temperature for 24 hours. 20.8 ml of BC was added to the resulting solution and stirred at 75° C. for 4 hours to obtain a polyamic acid solution (PA-1). The polymer solid content of the polyamic acid solution (PA-1) was 6% by weight. The weight average molecular weight of the polyamic acid solution (PA-1) was 23,000.

[Example 2]
In the synthesis of the polyamic acid solution (PA-1) described in Example 1, the diamines (DA-1) and (DA-3) and the tetracarboxylic dianhydride (AA-4) are listed in Table 1, respectively. was replaced with a diamine or a mixture of diamines and a tetracarboxylic dianhydride to prepare polyamic acid solutions (PA-2) and (PA-3) having a polymer solid concentration of 6% by weight.

<Preparation of substrate subjected to photo-alignment treatment>
[Example 3]
A substrate (PAF-1) subjected to photo-alignment treatment was produced by the following procedure.
(1) Polyamic acid solutions (PA-1) and (PA-3) were mixed at a weight ratio of 3:7, NMP was added to the mixture, and a photo-alignment agent having a polymer solid concentration of 4% by weight was prepared. was made.
(2) The photo-alignment agent prepared in (1) was spin-coated onto a glass substrate at 2000 rpm.
(3) Place the glass substrate obtained in (2) on a hot plate at 60 ° C. for 1 minute so that the surface of the glass substrate that is not spin-coated with the photo-alignment agent is in contact with the hot plate. A coating film was prepared on a glass substrate by removing the solvent contained in the solution.
(4) The coating film obtained in (3) was irradiated with linearly polarized light having a wavelength of 365 nm at an energy of 2 J/cm ² from a direction of 90 degrees to the coating film surface at room temperature.
(5) Then, it was baked in an oven set at 220° C. for 30 minutes to obtain a substrate (PAF-1) subjected to photo-alignment treatment.

A substrate (PAF-2) subjected to photo-alignment treatment was produced by the following procedure.
(1) NMP was added to the polyamic acid solution (PA-2) to prepare a photo-alignment agent having a polymer solid concentration of 4% by weight.
(2) The photo-alignment agent prepared in (1) was spin-coated onto a glass substrate at 2000 rpm.
(3) Place the glass substrate obtained in (2) on a hot plate at 80 ° C. for 1 minute so that the surface of the glass substrate that is not spin-coated with the photo-alignment agent is in contact with the hot plate. A coating film was prepared by removing the solvent.
(4) The coating film obtained in (3) was further baked in an oven at 220°C for 10 minutes.
(5) The coating film obtained in (4) was irradiated with linearly polarized light having a wavelength of 254 nm at an energy of 2 J/cm ² from a direction of 90 degrees to the coating surface at room temperature.
(6) After that, it was immersed in an ethyl lactate solution for 3 minutes at room temperature, rinsed with IPA for 1 minute, and dried in an oven at 80°C for 10 minutes to obtain a substrate (PAF-2) subjected to photo-alignment treatment. rice field.

<Production of polymerizable liquid crystal composition>
The structures of the polymerizable liquid crystal compounds used are shown below.

化合物（１－１－１）はMakromolekclare Chemie (1991), 192(1), 59-74に従い合成した。化合物（１－１－２）は市販品であり、ＢＡＳＦジャパン（株）製の重合性液晶化合物LC-242である。化合物（１－２－１）は特開２００３－２３８４９１号公報に従い合成した。化合物（１－１３－１）は国際公開２０１８／０３０１９０号の実施例３に従い合成した。化合物（２－１－１－１）および化合物（２－３－３－１）は、それぞれ特開２０１６－１２８４０３号公報の実施例２および実施例８に従い合成した。化合物（２－４－３－１）は、特開２０１７－１２５００９号公報の実施例２に従い合成した。

Compound (1-1-1) was synthesized according to Makromolekclare Chemie (1991), 192(1), 59-74. The compound (1-1-2) is a commercially available polymerizable liquid crystal compound LC-242 manufactured by BASF Japan. Compound (1-2-1) was synthesized according to JP-A-2003-238491. Compound (1-13-1) was synthesized according to Example 3 of WO2018/030190. Compound (2-1-1-1) and compound (2-3-3-1) were synthesized according to Example 2 and Example 8 of JP-A-2016-128403, respectively. Compound (2-4-3-1) was synthesized according to Example 2 of JP-A-2017-125009.

[Example 4]
The amounts shown in Table 2 were mixed to prepare polymerizable liquid crystal compositions (S-1) to (S-5). Polymerizable liquid crystal compositions (S-1) to (S-5) contain EB3703 (amine-modified epoxy acrylate), which is a polymerizable compound having one or more amino groups and one or more hydroxyl groups, as an adhesion promoter. It is a polymerizable liquid crystal composition of the present invention.

[Comparative Example 1]
They were mixed at the ratios shown in Table 3 to prepare polymerizable liquid crystal compositions (SC-1) to (SC-6). Polymerizable liquid crystal compositions (SC-1) to (SC-6) contain an adhesion promoter, but the adhesion promoter is not a polymerizable compound having one or more amino groups and one or more hydroxyl groups. . Moreover, the polymerizable liquid crystal composition (SC-7) does not contain an adhesion promoter.

<Preparation of polymerizable liquid crystal composition solution>
[Example 9]
The polymerizable liquid crystal composition shown in Table 4 and a solvent were mixed to prepare a polymerizable liquid crystal composition solution, and the name shown in Table 4 was given.

[Comparative Example 3]
The polymerizable liquid crystal composition described in Table 5 and a solvent were mixed to prepare a polymerizable liquid crystal composition solution, and the name described in Table 5 was given.

<Preparation of retardation film>
[Example 10]
A retardation film was produced by the following procedure.
(1) The polymerizable liquid crystal composition solution was spin-coated onto the alignment-treated surfaces produced in Example 3 and Comparative Example 1.
(2) The glass substrate obtained in (1) was placed so that the surface of the glass substrate not spin-coated with the polymerizable liquid crystal composition solution was in contact with a hot plate, and heated at 60° C. for 3 minutes with a hot plate.
(3) Subsequently, the substrate obtained in (2) was cooled at room temperature for 3 minutes to form a coating film on the oriented surface of the glass substrate.
(4) At room temperature in a nitrogen atmosphere, the coating film made of the polymerizable liquid crystal composition obtained in (3) is irradiated with light from an ultra-high pressure mercury lamp with a constant output from a vertical direction to obtain a polymerizable liquid crystal composition. A coating film consisting of was polymerized (cured).
The irradiation time is 5 to 40 seconds, using a 365 photodetector, so that the exposure of the surface of the polymerizable liquid crystal composition in step (4) to the light from the ultra-high pressure mercury lamp is 500 mJ/cm ² . adjusted between

Table 6 shows the physical properties of the retardation film made from the polymerizable liquid crystal composition solution. All of the retardation films (RF-1) to (RF-6), (RFC-1) to (RFC-5) and (RFC-7) were homogeneously oriented. (RFC-6) was cloudy and a homogeneously oriented retardation film could not be obtained.

From the above, it was found that the front contrast of the retardation films (RF-1) to (RF-6) was high.

The retardation film obtained in Example 10 was heat-treated in an oven at 200° C. for 30 minutes. The adhesion of the obtained retardation film was evaluated, and the results are shown in Table 7. The number of peeled squares in Table 7 is the number of peeled squares obtained by evaluating the retardation film by the cross-cut method.
Further, the retardation film obtained in Example 10 was heat-treated in an oven at 200°C for 30 minutes, and then heat-treated in an oven at 230°C for 60 minutes. The obtained retardation film was evaluated for heat resistance, and the results are shown in Table 7. Heat resistance (%)=Re(550) of retardation film after heat treatment/Re(550) of retardation film before heat treatment×100. A larger value indicates higher heat resistance.

From the above, it was found that the retardation films (RF-1) to (RF-6) had high heat resistance. It was also found that the retardation films (RF-1) to (RF-6) had high adhesiveness.
From these results, it was found that the retardation films (RF-1) to (RF-6) were excellent in front contrast, high adhesiveness, and high heat resistance.

Claims (10)

A polymerizable liquid crystal composition comprising a polymerizable liquid crystal compound (A) and an adhesion promoter (B) which is a polymerizable compound having one or more amino groups and one or more hydroxyl groups,
The polymerizable liquid crystal compound (A) is a compound having two or more polymerizable groups,
The adhesion promoter (B) is an amine-modified epoxy acrylate,
The content of the adhesion promoter (B) is 0.01 to 5% by weight with respect to the total amount of the polymerizable liquid crystal composition.
A polymerizable liquid crystal composition. 2. The polymerizable liquid crystal composition according to claim 1 , further comprising a surfactant, a polymerization initiator and a polymerization inhibitor. 3. A liquid crystal polymer having optical anisotropy obtained by polymerizing the polymerizable liquid crystal composition according to claim 1 or 2 . 4. The liquid crystal polymer according to claim 3 , wherein the liquid crystal molecules are fixed in a homogeneous orientation. 4. The liquid crystal polymer according to claim 3 , wherein the liquid crystal molecules are fixed in a twisted orientation. A retardation film obtained by directly laminating a layer of the liquid crystal polymer according to any one of claims 3 to 5 on an alignment-treated substrate. 7. The retardation film according to claim 6 , wherein the retardation film is directly laminated on a substrate that has undergone photo-alignment treatment. 8. The retardation film according to claim 6 , wherein an in-plane retardation Re(550) at a wavelength of 550 nm is 100 nm or more and 300 nm or less. A color filter in which the retardation film according to any one of claims 6 to 8 is laminated on a color filter layer directly or via a flattening layer. A display device comprising the retardation film according to any one of claims 6 to 8 .