JP6798097B2 - Liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal display element.

The field sequential full-color display method that does not require a color filter is characterized by using a backlight that lights in the order of "red → green → blue". A normal CRT or liquid crystal display has a frame time of 16.7 ms, but a field sequential full-color display method requires a high-speed response of 5.6 ms.
As an index showing high-speed response, the sum of τd and τr can be mentioned. τd is the falling response time of the liquid crystal, and τr is the rising response time of the liquid crystal. In order to satisfy the high-speed response in the field sequential full-color display method, it is desired that the sum of τd and τr is less than 1.5 ms.

Currently, liquid crystal materials called nematic liquid crystals in the market are generally used in flat panel displays such as televisions, monitors, mobile phones, smartphones, and tablet terminals. However, since the response speed of the nematic liquid crystal is as slow as about ten and several milliseconds to several milliseconds, improvement is desired. Since the response speed is greatly affected by the rotational viscosity γ1 of the liquid crystal and the elastic constant, improvement is being studied by developing a new compound and optimizing the composition, but the progress of the improvement is slow. On the other hand, a ferroelectric liquid crystal (FLC) using a smectic liquid crystal is capable of a high-speed response of several hundred microseconds. However, since there are only two states, light and dark, it is not easy to display the intermediate gradation required for full-color display, and a method such as area gradation is used.

Among the FLCs, the Polymer Stabilized V-Shaped-FLC (PSV-FLC) element, which is composed of a mixture of FLC and a monomer, forms a fine polymer network in a ferroelectric liquid crystal display, and is a feature of FLCs in high-speed response. In addition to this, it is possible to display intermediate gradations, and the impact resistance is also improved as compared with the conventional FLC (see, for example, Patent Document 1).

Further, in the composite material of the nematic liquid crystal and the polymer, when 70% by mass or more of the polymerizable compound is added to the nematic liquid crystal medium, a high-speed response of several tens of microseconds is obtained, but the driving voltage exceeds about 80V. Since it is not suitable for practical use and the effective birefringence is one digit or more lower than the liquid crystal birefringence used, the transmittance of the element is lowered. On the other hand, one or more kinds of polymerizable compounds of 0.3% by mass or more and less than 1% by mass are added to the liquid crystal medium, and polymerized or polymerized on the glass substrate interface by UV photopolymerization with or without applying a voltage. PS (polymer-stabilized) or PSA (polymer-sustained oriented) displays have been proposed in which fine protrusion structures obtained by cross-linking are formed to mainly induce pretilt. (See, for example, Patent Documents 2 to 6). However, there is room for improvement in these devices from the viewpoint of high-speed response. In particular, regarding the high-speed response of the rising speed of the liquid crystal display device, the liquid crystal composition has a low viscosity, a high dielectric constant, a low elastic constant, a pretilt angle, or an improvement in a driving method such as an overdrive method. Although various methods have been put into practical use, the current situation is that no effective method other than lowering the viscosity of the liquid crystal composition has been found for the falling speed, and improvement has been desired.

JP-A-2002-31821 Special Table 2013-536271 Special Table 2013-538249 Special Table 2012-527495 Special Table 2012-513482 Japanese Unexamined Patent Publication No. 2012-219270

The problem to be solved by the present invention is to improve the solubility of the polymerizable compound, suppress the increase in the driving voltage, suppress the reduction in the birefringence, improve the transmittance, and improve the fall time of the liquid crystal. This is to provide a liquid crystal display element having high transmittance and excellent high-speed response.

An object of the present invention is to form a polymer network having refractive anisotropy and an orientation function in the entire liquid crystal cell in a liquid crystal composition and a polymerizable liquid crystal composition containing a polymerizable compound to achieve a high-speed response. As a result, we focused on the optimum content of the polymerizable compound and completed the present invention.

[1] A polymer or a polymer is contained in a liquid crystal composition sandwiched between two transparent substrates having an electrode on at least one of them, and the content of the polymer or the copolymer is the liquid crystal composition and the polymer or the polymer. It is 1% by mass or more and less than 40% by mass of the total mass of the copolymer, and the polymer or the copolymer polymerizes one or more of the polymerizable compounds represented by the following general formula (X1b). A liquid crystal display element containing the obtained polymer or copolymer.

（式中、Ａ^８は水素原子又はメチル基を表し、６員環Ｔ^１、Ｔ^２及びＴ^３はそれぞれ独立して

(In the formula, A ⁸ represents a hydrogen atom or a methyl group, and the 6-membered rings T ¹ , T ² and T ³ are independent of each other.

のいずれか（ただしｍは、１から４の整数を表す。）を表し、
ｑは０又は１を表し、
Ｙ^１及びＹ^２はそれぞれ独立して単結合、−ＣＨ_２ＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＨ_２−、−ＣＯＯ−、−ＯＣＯ−、−Ｃ≡Ｃ−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−（ＣＨ_２）_４−、−ＣＨ_２ＣＨ_２Ｏ−、−ＯＣＨ_２ＣＨ_２−、−ＣＨ＝ＣＨＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２ＣＨ＝ＣＨ−、−ＣＯＯ−ＣＨ_２ＣＨ_２−、−ＯＣＯ−ＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２−ＣＯＯ−又は−ＣＨ_２ＣＨ_２−ＯＣＯ−を表すが、Ｙ^１及びＹ^２の少なくとも一つは−ＣＯＯ−ＣＨ_２ＣＨ_２−、−ＯＣＯ−ＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２−ＣＯＯ−又は−ＣＨ_２ＣＨ_２−ＯＣＯ−を表し、ｑが０を表す場合、Ｙ^１は−ＣＯＯ−ＣＨ_２ＣＨ_２−、−ＯＣＯ−ＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２−ＣＯＯ−又は−ＣＨ_２ＣＨ_２−ＯＣＯ−を表し、
Ｙ^３及びＹ^４はそれぞれ独立して単結合、炭素原子数１〜１２のアルキレン基（該アルキレン基中の１個又は２個以上のメチレン基は、酸素原子が相互に直接結合しないものとして、それぞれ独立して酸素原子、−ＣＯ−、−ＣＯＯ−又は−ＯＣＯ−で置換されていてもよく、該アルキレン基中の１個又は２個以上の水素原子はそれぞれ独立してフッ素原子、メチル基又はエチル基で置換されていてもよい。）を表し、
Ｂ^８は水素原子、シアノ基、ハロゲン原子又は炭素原子数１〜１４のアルキル基を表し、該アルキル基は末端の−ＣＨ_３がアクリロイル基又はメタクリロイル基に置換されても良い。）
［２］液晶組成物中に重合体又は共重合体としてポリマーネットワークを有し、透明基板上に液晶組成物を配向させるための配向層を有する前記［１］に記載の液晶表示素子。
［３］ポリマーネットワークが一軸性の屈折率異方性を有し、ポリマーネットワークの光軸方向又は配向容易軸方向と低分子液晶の配向容易軸方向が同一方向である前記［２］に記載の液晶表示素子。
［４］透明基板に対して低分子液晶の液晶分子が０〜９０°のプレチルト角を成すように形成された前記［１］〜［３］のいずれか１つに記載の液晶表示素子。
［５］セル断面方向に対して少なくともセル厚の０．５％以上の厚さのポリマーネットワーク層が形成されている前記［２］〜［４］のいずれか１つに記載の液晶表示素子。
［６］前記重合体又は共重合体が、少なくとも一方に電極を有する２枚の透明基板間に挟持した液晶組成物中の重合性化合物を、液晶層の温度範囲を−５０℃から３０℃としながらエネルギー線を照射することにより重合することで得られた重合体又は共重合体である前記［１］〜［５］のいずれか１つに記載の液晶表示素子。
［７］前記重合体又は共重合体が、少なくとも一方に電極を有する２枚の透明基板間に挟持した液晶組成物中の重合性化合物を、エネルギー線照射前のプレチルト角が０．１〜３０度になるような電圧を印加しながらエネルギー線を照射することにより重合することで得られた重合体又は共重合体である前記［１］〜［６］のいずれか１つに記載の液晶表示素子。
［８］前記重合体又は共重合体が、下記一般式（Ｉ）で表される重合性化合物の１種又は２種以上を重合させて得た重合体又は共重合体を含有するものである前記［１］〜［７］のいずれか１つに記載の液晶表示素子。

(However, m represents an integer from 1 to 4).
q represents 0 or 1 and represents
Y ¹ and Y ² are independently single-coupled, -CH ₂ CH _2- , -CH ₂ O-, -OCH _2- , -COO-, -OCO-, -C≡C-, -CH = CH- _{, -CF = CF -, - OCF} 2 -, - CF 2 O -, - (CH 2) 4 -, - CH 2 CH 2 O -, - OCH 2 CH 2 -, - CH = CHCH 2 CH 2 -, _{-CH 2 CH 2 CH = CH -} , - COO-CH 2 CH 2 -, - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO- or represents a _-CH 2 _CH 2 -OCO-, Y ¹ and at least one ^{Y 2} is _{-COO-CH 2 CH 2 -,} - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO- or _-CH 2 _CH 2 -OCO- represent, q is 0 when referring to, ^{Y 1} is _{-COO-CH 2 CH 2 -,} - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO- or _-CH 2 _CH 2 -OCO- represent,
Y ³ and Y ⁴ are independently single-bonded, and alkylene groups having 1 to 12 carbon atoms (one or two or more methylene groups in the alkylene group do not directly bond oxygen atoms to each other. They may be independently substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkylene group are independently a fluorine atom and a methyl group, respectively. Alternatively, it may be substituted with an ethyl group.)
B ⁸ represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group having 1 to 14 carbon atoms, and the terminal −CH _{3 of the} alkyl group may be replaced with an acryloyl group or a methacryloyl group. )
[2] The liquid crystal display element according to the above [1], which has a polymer network as a polymer or a copolymer in the liquid crystal composition, and has an alignment layer for orienting the liquid crystal composition on a transparent substrate.
[3] The above-mentioned [2], wherein the polymer network has uniaxial refractive index anisotropy, and the optical axis direction or the easy orientation axial direction of the polymer network and the easy axis direction of the low molecular weight liquid crystal are in the same direction. Liquid crystal display element.
[4] The liquid crystal display element according to any one of the above [1] to [3], wherein liquid crystal molecules of a low molecular weight liquid crystal are formed so as to form a pretilt angle of 0 to 90 ° with respect to a transparent substrate.
[5] The liquid crystal display device according to any one of [2] to [4] above, wherein a polymer network layer having a thickness of at least 0.5% or more of the cell thickness is formed in the cross-sectional direction of the cell.
[6] The temperature range of the liquid crystal layer of the polymerizable compound in the liquid crystal composition in which the polymer or copolymer is sandwiched between two transparent substrates having electrodes on at least one of them is set to −50 ° C. to 30 ° C. The liquid crystal display element according to any one of the above [1] to [5], which is a polymer or copolymer obtained by polymerizing by irradiating with energy rays.
[7] The polymer or copolymer sandwiches a polymerizable compound in a liquid crystal composition sandwiched between two transparent substrates having electrodes on at least one of them, and has a pretilt angle of 0.1 to 30 before irradiation with energy rays. The liquid crystal display according to any one of the above [1] to [6], which is a polymer or copolymer obtained by polymerizing by irradiating an energy ray while applying a voltage such as a degree. element.
[8] The polymer or copolymer contains a polymer or copolymer obtained by polymerizing one or more of the polymerizable compounds represented by the following general formula (I). The liquid crystal display element according to any one of the above [1] to [7].

（式中、Ｗ^１及びＷ^２はそれぞれ独立的に単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、Ｙ^１及びＹ^２はそれぞれ独立的に−ＣＯＯ−又は−ＯＣＯ−を表し、ｐ及びｑはそれぞれ独立的に２〜１３の整数を表すが、式中に存在する１，４−フェニレン基は炭素原子数１〜７のアルキル基、アルコキシ基、アルカノイル基、シアノ基又はハロゲン原子で一つ以上置換されていても良い。）
［９］前記重合体又は共重合体が、下記一般式（ＩＩ）で表される重合性化合物の１種又は２種以上を重合させて得た重合体又は共重合体を含有するものである前記［１］〜［８］のいずれか１つに記載の液晶表示素子。

(In the equation, W ¹ and W ² independently represent single bonds, -O-, -COO- or -OCO-, and Y ¹ and Y ² independently represent -COO- or -OCO-, respectively. , P and q each independently represent an integer of 2 to 13, but the 1,4-phenylene group present in the formula is an alkyl group, an alkoxy group, an alkanoyl group, a cyano group or a halogen having 1 to 7 carbon atoms. It may be substituted with one or more atoms.)
[9] The polymer or copolymer contains a polymer or copolymer obtained by polymerizing one or more of the polymerizable compounds represented by the following general formula (II). The liquid crystal display element according to any one of the above [1] to [8].

（式中、Ｗ^３及びＷ^４はそれぞれ独立的に単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、Ｙ^３は−ＣＯＯ−又は−ＯＣＯ−を表し、ｒ及びｓはそれぞれ独立的に２〜１３の整数を表すが、式中に存在する１，４−フェニレン基は炭素原子数１〜７のアルキル基、アルコキシ基、アルカノイル基、シアノ基又はハロゲン原子で一つ以上置換されていても良い。）
［１０］前記重合体又は共重合体が、下記一般式（Ｖ）及び一般式（ＶＩ）で表される化合物から選ばれる１種又は２種以上の重合性化合物を重合させて得た重合体又は共重合体を含有する前記［１］〜［９］のいずれか１つに記載の液晶表示素子。

(In the equation, W ³ and W ⁴ independently represent single bonds, -O-, -COO- or -OCO-, Y ³ represents -COO- or -OCO-, and r and s are independent, respectively. The 1,4-phenylene group existing in the formula is substituted with one or more alkyl groups, alkoxy groups, alkanoyl groups, cyano groups or halogen atoms having 1 to 7 carbon atoms. You may be.)
[10] The polymer or copolymer is a polymer obtained by polymerizing one or more polymerizable compounds selected from the compounds represented by the following general formulas (V) and general formulas (VI). The liquid crystal display element according to any one of the above [1] to [9], which contains a copolymer.

（式中、Ｘ^１及びＸ^２はそれぞれ独立して、水素原子又はメチル基を表し、Ｓｐ^１及びＳｐ^２はそれぞれ独立して、単結合、炭素原子数１〜１２のアルキレン基又は−Ｏ−（ＣＨ_２）_ｓ−（式中、ｓは１〜１１の整数を表し、酸素原子は芳香環に結合するものとする。）を表し、Ｕは炭素原子数２〜２０の直鎖もしくは分岐多価アルキレン基又は炭素原子数５〜３０の多価環状置換基を表すが、多価アルキレン基中のアルキレン基は酸素原子が隣接しない範囲で酸素原子により置換されていてもよく、炭素原子数５〜２０のアルキル基（基中のアルキレン基は酸素原子が隣接しない範囲で酸素原子により置換されていてもよい。）又は環状置換基により置換されていてもよく、ｋは１〜５の整数を表す。式中の全ての１，４−フェニレン基は、任意の水素原子が−ＣＨ_３、−ＯＣＨ_３、フッ素原子、又はシアノ基に置換されていてもよい。但し、一般式（Ｘ１ｂ）で表される重合性化合物を除く。）

(In the formula, X ¹ and X ² independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² independently represent a single bond, an alkylene group having 1 to 12 carbon atoms or −O−. (CH ₂ ) represents _s − (in the formula, s represents an integer of 1 to 11 and an oxygen atom is bonded to an aromatic ring), and U represents a linear or branched number of carbon atoms 2 to 20. It represents a valent alkylene group or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which oxygen atoms are not adjacent to each other, and the number of carbon atoms is 5. It may be substituted with an alkyl group of ~ 20 (the alkylene group in the group may be substituted with an oxygen atom to the extent that the oxygen atom is not adjacent) or a cyclic substituent, and k is an integer of 1 to 5. For all 1,4-phenylene groups in the formula, any hydrogen atom may be substituted with -CH ₃ , -OCH ₃ , fluorine atom, or cyano group, provided that the general formula (X1b) is used. Excluding the polymerizable compounds represented.)

（式中、Ｘ^３は、水素原子又はメチル基を表し、Ｓｐ^３は、単結合、炭素原子数１〜１２のアルキレン基又は−Ｏ−（ＣＨ_２）_ｔ−（式中、ｔは２〜１１の整数を表し、酸素原子は芳香環に結合するものとする。）を表し、Ｖは炭素原子数２〜２０の直鎖もしくは分岐多価アルキレン基又は炭素原子数５〜３０の多価環状置換基を表すが、多価アルキレン基中のアルキレン基は酸素原子が隣接しない範囲で酸素原子により置換されていてもよく、炭素原子数５〜２０のアルキル基（基中のアルキレン基は酸素原子が隣接しない範囲で酸素原子により置換されていてもよい。）又は環状置換基により置換されていてもよく、Ｗは水素原子、ハロゲン原子又は炭素原子数１〜１５のアルキルを表す。式中の全ての１，４−フェニレン基は、任意の水素原子が−ＣＨ_３、−ＯＣＨ_３、フッ素原子、又はシアノ基に置換されていてもよい。但し、一般式（Ｘ１ｂ）で表される重合性化合物を除く。）
［１１］前記液晶組成物が、下記一般式（ＬＣ）で表される液晶化合物を含有する前記［１］〜［１０］のいずれか１つに記載の液晶表示素子。

(In the formula, X ³ represents a hydrogen atom or a methyl group, Sp ³ is a single bond, an alkylene group having 1 to 12 carbon atoms or −O− (CH ₂ ) _t − (in the formula, t is 2 to 2). It represents an integer of 11, and the oxygen atom is bound to the aromatic ring.), Where V is a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent ring having 5 to 30 carbon atoms. Although it represents a substituent, the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which oxygen atoms are not adjacent to each other, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group is an oxygen atom). May be substituted with an oxygen atom to the extent that they are not adjacent to each other) or with a cyclic substituent, and W represents a hydrogen atom, a halogen atom or an alkyl having 1 to 15 carbon atoms. All 1,4-phenylene groups may have any hydrogen atom substituted with -CH ₃ , -OCH ₃ , a fluorine atom, or a cyano group, provided that they are polymerizable represented by the general formula (X1b). Excluding compounds.)
[11] The liquid crystal display device according to any one of the above [1] to [10], wherein the liquid crystal composition contains a liquid crystal compound represented by the following general formula (LC).

（一般式（ＬＣ）中、Ｒ^ＬＣは、炭素原子数１〜１５のアルキル基を表す。該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−又は−Ｃ≡Ｃ−で置換されてよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子に置換されていてもよい。Ａ^ＬＣ１及びＡ^ＬＣ２は、それぞれ独立して、下記の基（ａ）、基（ｂ）及び基（ｃ）からなる群より選ばれる基を表す。
（ａ）トランス−１，４−シクロヘキシレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は酸素原子又は硫黄原子で置換されていてもよい。）、
（ｂ）１，４−フェニレン基（この基中に存在する１個のＣＨ基又は隣接していない２個以上のＣＨ基は窒素原子で置換されていてもよい。）、
（ｃ）１，４−ビシクロ（２．２．２）オクチレン基、ナフタレン−２，６−ジイル基、デカヒドロナフタレン−２，６−ジイル基、１，２，３，４−テトラヒドロナフタレン−２，６−ジイル基、又はクロマン−２，６−ジイル基。
前記の基（ａ）、基（ｂ）又は基（ｃ）に含まれる１つ又は２つ以上の水素原子はそれぞれ、フッ素原子、塩素原子、−ＣＦ_３又は−ＯＣＦ_３で置換されていてもよい。
Ｚ^ＬＣは単結合、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−Ｃ≡Ｃ−、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表す。
Ｙ^ＬＣは、水素原子、フッ素原子、塩素原子、シアノ基、及び炭素原子数１〜１５のアルキル基を表す。該アルキル基中の１つ又は２つ以上のＣＨ_２基は、酸素原子が直接隣接しないように、−Ｏ−、−ＣＨ＝ＣＨ−、−ＣＯ−、−ＯＣＯ−、−ＣＯＯ−、−Ｃ≡Ｃ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−で置換されてよく、該アルキル基中の１つ又は２つ以上の水素原子は任意にハロゲン原子によって置換されていてもよい。
ａは１〜４の整数を表す。ａが２、３又は４を表し、一般式（ＬＣ）中にＡ^ＬＣ１が複数存在する場合、複数存在するＡ^ＬＣ１は、同一であっても異なっていてもよく、Ｚ^ＬＣが複数存在する場合、複数存在するＺ^ＬＣは、同一であっても異なっていてもよい。）
［１２］１質量％以上１０質量％未満の重合性化合物を含有する重合性液晶組成物を用い屈折率異方性又は配向容易軸方向を有するポリマーネットワークを形成した前記［６］〜［１１］のいずれか１つに記載の液晶表示素子。
［１３］１０質量％以上４０質量％未満の重合性化合物を含有する重合性液晶組成物を用い屈折率異方性又は配向容易軸方向を有するポリマーネットワークを形成した前記［６］〜［１１］のいずれか１つに記載の液晶表示素子。
［１４］セル構造がＶＡモード、ＩＰＳモード、ＦＦＳモード、ＶＡ−ＴＮモード、ＴＮモード、ＥＣＢモードである前記［１］〜［１３］のいずれか１つに記載の液晶表示素子。
［１５］前記［１］〜［１４］に記載の重合性液晶組成物。

(In the general formula ^{(LC), R LC} is one or two or more CH ₂ groups in. The alkyl group represents an alkyl group having 1 to 15 carbon atoms, as the oxygen atoms are not directly adjacent, It may be substituted with −O−, −CH = CH−, −CO−, −OCO−, −COO− or −C≡C−, and one or more hydrogen atoms in the alkyl group are optionally It may be substituted with a halogen atom. A ^LC1 and A ^LC2 each independently represent a group selected from the group consisting of the following groups (a), groups (b) and groups (c).
(A) Trans-1,4-cyclohexylene group (one CH ₂ group existing in this group or two or more CH _two groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom. .),
(B) 1,4-phenylene group (one CH group existing in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom),
(C) 1,4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2 , 6-Diyl group, or Chroman-2,6-Diyl group.
Even if one or more hydrogen atoms contained in the group (a), group (b) or group (c) are substituted with a fluorine atom, a chlorine atom, -CF ₃ or -OCF ₃ , respectively. Good.
Z ^LC is a single bond, -CH = CH -, - CF = CF -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - OCH 2 -, - CH 2 O-, Represents −OCF _2- , −CF ₂ O−, −COO− or −OCO−.
Y ^LC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, and an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group are -O-, -CH = CH-, -CO-, -OCO-, -COO-, -C so that oxygen atoms are not directly adjacent to each other. _{≡C -, - CF 2 O -} , - OCF 2 - may be substituted with, one or more hydrogen atoms in the alkyl group may be optionally substituted by a halogen atom.
a represents an integer of 1 to 4. When a represents 2, 3 or 4, and there are a plurality of A ^LC1s in the general formula (LC), the plurality of A ^LC1s may be the same or different, and when a plurality of Z ^LCs are present. , A plurality of Z ^LCs may be the same or different. )
[12] The above-mentioned [6] to [11], wherein a polymer network having refractive index anisotropy or easy orientation is formed by using a polymerizable liquid crystal composition containing 1% by mass or more and less than 10% by mass of a polymerizable compound. The liquid crystal display element according to any one of.
[13] The above-mentioned [6] to [11], wherein a polymer network having refractive index anisotropy or easy orientation is formed by using a polymerizable liquid crystal composition containing a polymerizable compound of 10% by mass or more and less than 40% by mass. The liquid crystal display element according to any one of.
[14] The liquid crystal display element according to any one of the above [1] to [13], wherein the cell structure is VA mode, IPS mode, FFS mode, VA-TN mode, TN mode, and ECB mode.
[15] The polymerizable liquid crystal composition according to the above [1] to [14].

According to the present invention, the rise of the driving voltage is suppressed, the reduction of the birefringence is suppressed to improve the transmittance, and the fall time of the liquid crystal is improved, thereby excellent in high transmittance and high-speed response. A liquid crystal display element can be provided.

It is a schematic diagram of the liquid crystal display element of this invention. It is a partially enlarged view of FIG. It is sectional drawing of the liquid crystal display element of this invention. It is a partially enlarged view of FIG. It is sectional drawing of the liquid crystal display element of this invention. It is a schematic diagram of the liquid crystal display element of this invention. It is a partially enlarged view of FIG. It is sectional drawing of the liquid crystal display element of this invention. It is a schematic diagram which shows the liquid crystal molecular arrangement and the polymer network structure of the VA type liquid crystal display device in this invention. It is a schematic diagram which shows the electrode structure and the liquid crystal molecular arrangement of the oblique electric field type liquid crystal display device in this invention. It is a schematic diagram which shows the electrode structure of the 8-division diagonal electric field type liquid crystal display device in this invention. It is a schematic diagram of the molecular arrangement of the liquid crystal molecule of the VA-TN liquid crystal cell in this invention. It is a schematic diagram of the electrode structure of the fishbone type VA liquid crystal cell in an Example. It is a top view of the oblique electric field test cell electrode structure and the schematic diagram of the liquid crystal molecular motion in an Example. It is a top view of the electrode structure of the test cell for IPS mode which was divided into orientations used in this invention, and is a schematic diagram which shows the behavior of a liquid crystal molecule. It is a top view of the electrode structure of the orientation-divided FFS mode test cell used in this invention.

<Liquid crystal composition>
[Liquid crystal compound]
The liquid crystal composition used in the present invention preferably contains a liquid crystal compound represented by the general formula (LC).

In the general formula ^{(LC), R LC} represents an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group are -O-, -CH = CH-, -CO-, -OCO-, -COO- or -C so that oxygen atoms are not directly adjacent to each other. It may be substituted with ≡ C−, and one or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom. Alkyl group R ^LC may be respectively branched chain groups, may be straight chain groups, but is preferably a linear group.

In the general formula (LC), A ^LC1 and A ^LC2 each independently represent a group selected from the group consisting of the following groups (a), groups (b) and groups (c).
(A) Trans-1,4-cyclohexylene group (one CH ₂ group existing in this group or two or more CH _two groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom. .),
(B) 1,4-phenylene group (one CH group existing in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom),
(C) 1,4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2 , 6-Diyl group, or Chroman-2,6-Diyl group.

Even if one or more hydrogen atoms contained in the group (a), group (b) or group (c) are substituted with a fluorine atom, a chlorine atom, -CF ₃ or -OCF ₃ , respectively. Good.
In the general formula ^{(LC), Z} LC is a single bond, -CH = CH -, - CF = CF -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - OCH 2 - _{, -CH 2 O -, - OCF} 2 -, - CF 2 O -, - COO- or an -OCO-.
In the general formula (LC), ^YLC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, and an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group are -O-, -CH = CH-, -CO-, -OCO-, -COO-, -C so that oxygen atoms are not directly adjacent to each other. _{≡C -, - CF 2 O -} , - OCF 2 - may be substituted with, one or more hydrogen atoms in the alkyl group may be optionally substituted by a halogen atom.

In the general formula (LC), a represents an integer of 1 to 4. When a represents 2, 3 or 4, and there are a plurality of A ^LC1s in the general formula (LC), the plurality of A ^LC1s may be the same or different, and when a plurality of Z ^LCs are present. , A plurality of Z ^LCs may be the same or different.
The compound represented by the general formula (LC) is preferably one or more compounds selected from the compound group represented by the following general formula (LC1) and general formula (LC2).

In the general formula (LC1) or (LC2), R ^LC11 and R ^LC21 each independently represent an alkyl group having 1 to 15 carbon atoms, and one or two or more CH ₂ groups in the alkyl group , Can be substituted with -O-, -CH = CH-, -CO-, -OCO-, -COO- or -C≡C- so that the oxygen atoms are not directly adjacent, one of the alkyl groups. Alternatively, the two or more hydrogen atoms may be optionally substituted with halogen atoms. As the compounds represented by the general formula (LC1) or (LC2), R ^LC11 and R ^LC21 independently have an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and the number of carbon atoms, respectively. 2 to 7 alkenyl groups are preferable, alkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, and alkenyl groups having 2 to 5 carbon atoms are more preferable, and linearity is further preferable. Most preferably, the alkoxy group has the following structure.

（式中、環構造へは右端で結合するものとする。）

(In the formula, it shall be connected to the ring structure at the right end.)

In the general formula (LC1) or (LC2), A ^LC11 and A ^LC21 each independently represent any of the following structures. In the structure, one or more CH _two groups in the cyclohexylene group may be substituted with an oxygen atom, and one or more CH groups in the 1,4-phenylene group may be a nitrogen atom. It may be substituted with, and one or more hydrogen atoms in the structure may be substituted with a fluorine atom, a chlorine atom, -CF ₃ or -OCF ₃ .

As the compound represented by the general formula (LC1) or (LC2), A ^LC11 and A ^LC21 each independently preferably have any of the following structures.

In the general formula (LC1) or ^{(LC2), X LC11, X} LC12, X LC21 ~X LC23 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a -CF ₃ or -OCF ^{_3, Y LC11} and Y ^LC21 independently represents a hydrogen atom, a chlorine atom, a fluorine atom, a cyano group, -CF ₃ , -OCH ₂ F, -OCHF ₂ or -OCF ₃ . As the compound represented by the general formula (LC1) or (LC2), Y ^LC11 and Y ^LC21 are each independently preferably a fluorine atom, a cyano group, -CF ₃ or -OCF ₃ , and the fluorine atom or -OCF ₃ is preferable. More preferably, a fluorine atom is particularly preferable.

In the general formula (LC1) or (LC2), Z ^LC11 and Z ^LC21 are independently single-bonded, −CH = CH−, −CF = ^CF− , ^−C≡C− , −CH ₂ CH ₂₋ , respectively. _{- (CH 2) 4 -,} - OCH 2 -, - CH 2 O -, - OCF 2 -, - CF 2 O -, - COO- or an -OCO-. Examples of the compound represented by the general formula (LC1) or ^{(LC2), Z LC11} and ^{Z LC21} are each independently a single _{bond, -CH 2 CH 2 -, -} COO -, - OCO -, - OCH 2 -, -CH ₂ O-, -OCF _2- or -CF ₂ O- are preferred, single bond, -CH ₂ CH _2- , -OCH _2- , -OCF _2- or -CF ₂ O- are more preferred, single bond , -OCH _2- or -CF ₂ O- is even more preferred.

In the general formula (LC1) or (LC2), m ^LC11 and m ^LC21 each independently represent an integer of 1 to 4. As the compound represented by the general formula (LC1) or (LC2), m ^LC11 and m ^LC21 are preferably 1, 2 or 3 independently of each other, and when storage stability at low temperature and response speed are important. 1 or 2 is more preferable, and 2 or 3 is more preferable when improving the upper limit of the nematic phase upper limit temperature. When a plurality of A ^LC11 , A ^LC21 , Z ^LC11 and Z ^LC21 are present in the general formula (LC1) or (LC2), they may be the same or different.

The compound represented by the general formula (LC1) is one or more compounds selected from the group consisting of compounds represented by the following general formulas (LC1-a) to general formula (LC1-c). Is preferable.

In the general formula (LC1-a) ~ (LC1 -c), and R ^LC11, Y ^{LC11, X LC11} and ^{X LC12 R} LC11 is in formula each independently ^{(LC1), Y LC11, X} LC11 and ^{X LC12} Represents the same meaning. As the compounds represented by the general formulas (LC1-a) to the general formula (LC1-c), R ^LC11 independently ^contains an alkyl group having 1 to 7 carbon atoms and an alkoxy group having 1 to 7 carbon atoms. An alkenyl group having 2 to 7 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and an alkenyl group having 2 to 5 carbon atoms are more preferable. ^Further, preferably a hydrogen atom or a fluorine atom ^{X LC11} and ^{X LC12} each ^{independently, Y LC11} each independently a fluorine atom, -CF ₃ or -OCF ₃ are preferred.

In the general formulas (LC1-a) to (LC1-c), A ^LC1a1 , A ^LC1a2 and A ^LC1b1 are trans-1,4-cyclohexylene group, tetrahydropyran-2,5-diyl group, 1,3-dioxane. Represents a −2,5-diyl group. Further, in the general formulas (LC1-a) to (LC1-c), X ^LC1b1 , X ^LC1b2 , and X ^{LC1c1 to} X ^LC1c4 independently ^generate hydrogen atom, chlorine atom, fluorine atom, -CF ₃ or -OCF ₃ . Represent. As the compounds represented by the general formulas (LC1-a) to the general formula (LC1-c), X ^LC1b1 , X ^LC1b2 , and X ^{LC1c1 to} X ^LC1c4 are preferably independent hydrogen atoms or fluorine atoms, respectively.

Further, the general formula (LC1) is preferably one or more compounds selected from the group consisting of compounds represented by the following general formulas (LC1-d) to the general formula (LC1-p).

In the general formula (LC1-d) ~ (LC1 -p), and R ^LC11, Y ^{LC11, X LC11} and ^{X LC12 R} LC11 is in formula each independently ^{(LC1), Y LC11, X} LC11 and ^{X LC12} Represents the same meaning. As the compounds represented by the general formulas (LC1-d) to (LC1-p), R ^LC11 independently has an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and a carbon atom number. 2 to 7 alkenyl groups are preferable, and alkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, and alkenyl groups having 2 to 5 carbon atoms are more preferable. ^{Further, X LC11} and ^{X LC12} is preferably a hydrogen atom or a fluorine atom independently. Y ^LC11 is preferably a fluorine atom, −CF ₃ or −OCF ₃ independently of each other.

In the general formulas (LC1-d) to (LC1-p), A ^LC1d1 , A ^LC1f1 , A ^LC1g1 , A ^LC1j1 , A ^LC1k1 , A ^LC1k2 , and A ^{LC1m1 to} A ^LC1m3 are independently 1,4-phenylene groups. , Trans-1,4-cyclohexylene group, tetrahydropyran-2,5-diyl group, or 1,3-dioxane-2,5-diyl group.

In the general formula (LC1-d) ~ (LC1 -p), X LC1d1, X LC1d2, X LC1f1, X LC1f2, X LC1g1, X LC1g2, X LC1h1, X LC1h2, X LC1i1, X LC1i2, X LC1j1 ~X LC1j4 , X ^LC1k1 , X ^LC1k2 , X ^LC1m1 and X ^LC1m2 independently represent hydrogen atom, chlorine atom, fluorine atom, -CF ₃ or -OCF ₃ . As the compounds represented by the general formulas (LC1-d) to (LC1-m), X ^{LC1d1 to} X ^LC1m2 are preferably independent hydrogen atoms or fluorine atoms, respectively.

In the general formulas (LC1-d) to (LC1-p), Z ^LC1d1 , Z ^LC1e1 , Z ^LC1j1 , Z ^LC1k1 , and Z ^LC1m1 are independently single-bonded, -CH = CH-, -CF = CF-,-. _{C≡C -, - CH 2 CH 2} -, - (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - OCF 2 -, - CF 2 O -, - COO- or -OCO- the Represent. The general formula (LC1-d) ~ compound represented by ^{(LC1-p), Z LC1d1} ~Z LC1m1 each independently represent a single _{bond, -CH 2 CH 2 -, -} (CH 2) 4 -, - CF ₂ O- or -OCH _2- is preferable.

The compound represented by the general formulas (LC1-d) to (LC1-p) is one selected from the group consisting of the compounds represented by the following general formulas (LC1-1) to the general formula (LC1-45). It is preferably two or more compounds. From the general formula (LC1-1) to the general formula (LC1-45), R ^LC11 independently represents an alkyl group having 1 to 7 carbon atoms.

The general formula (LC2) is preferably one or more compounds selected from the group consisting of compounds represented by the following general formulas (LC2-a) to the general formula (LC2-g).

In the general formulas (LC2-a) to (LC2-g), R ^LC21 , Y ^LC21 , and X ^{LC21 to} X ^LC23 are independently referred to as R ^LC21 , Y ^LC21 , and X ^{LC21 to} X ^LC23 in the general formula (LC2). Represents the same meaning. As the compounds represented by the general formulas (LC2-a) to (LC2-g), R ^LC21 independently has an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and a carbon atom number. 2 to 7 alkenyl groups are preferable, and alkyl groups having 1 to 5 carbon atoms, alkoxy groups having 1 to 5 carbon atoms, and alkenyl groups having 2 to 5 carbon atoms are more preferable. Further, X ^{LC21 to} X ^LC23 are preferably independently hydrogen atoms or fluorine atoms, and Y ^LC21 is independently preferably fluorine atoms, −CF ₃ or −OCF ₃ .

In the general formulas (LC2-a) to (LC2-g), X ^{LC2d1 to} X ^LC2d4 , X ^{LC2e1 to} X ^LC2e4 , X ^{LC2f1 to} X ^LC2f4 and X ^{LC2g1 to} X ^LC2g4 are independently hydrogen atoms, chlorine atoms, and fluorine, respectively. Represents an atom, -CF ₃ or -OCF ₃ . As the compounds represented by the general formulas (LC2-a) to (LC2-g), X ^{LC2d1 to} X ^LC2g4 are preferably independently hydrogen atoms or fluorine atoms, respectively.

In the general formulas (LC2-a) to (LC2-g), Z ^LC2a1 , Z ^LC2b1 , Z ^LC2c1 , Z ^LC2d1 , Z ^LC2e1 , Z ^LC2f1 and Z ^LC2g1 are independently single-bonded, -CH = CH-,-. _{CF = CF -, - C≡C -} , - CH 2 CH 2 -, - (CH 2) 4 -, - OCH 2 -, - CH 2 O -, - OCF 2 -, - CF 2 O -, - COO Represents − or −OCO−. As the compounds represented by the general formulas (LC2-a) to (LC2-g), Z ^{LC2a1 to} Z ^LC2g4 are preferably −CF ₂ O− or −OCH ₂ − independently of each other.

The compound represented by the general formula (LC) is preferably one or more compounds selected from the compound group represented by the following general formulas (LC3) to (LC5).

^(Wherein represents ^{R LC31, R LC32, R LC41} , R LC42, alkyl groups ^{R LC51} and ^{R LC52} is 1-15 carbon atoms independently, one in the alkyl group or two or more -CH ₂ -, as the oxygen atoms are not directly adjacent, -O -, - CH = CH -, - CO -, - OCO -, - COO- or -C≡C- may be substituted with said alkyl one or more hydrogen atoms in the group may be optionally substituted by a halogen ^{atom, a LC31, a LC32, a} LC41, a LC42, a LC51 and ^{a LC52} each independently any of the following Structure

(In the structure, one or more -CH _2- in the cyclohexylene group may be substituted with an oxygen atom, and one or more -CH- in the 1,4-phenylene group may be substituted. It may be substituted with a nitrogen atom, and one or more hydrogen atoms in the structure may be substituted with a fluorine atom, a chlorine atom, -CF ₃ or -OCF ₃ ). It indicates ^{whether, Z LC31, Z LC32, Z} LC41, Z LC42, Z LC51 and ^{Z LC51} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - ( _{CH 2) 4 -, - COO} -, - OCH 2 -, - CH 2 O -, - OCF 2 - or _-CF 2 O-a represents, ^{Z 5} is -CH ₂ - represents an or an oxygen ^{atom, X LC41} is represents a hydrogen atom or a fluorine ^{atom, m LC31, m LC32, m} LC41, m LC42, m LC51 and ^{m LC52} represent 0-3 ^{independently, m LC31 + m LC32, m} LC41 + m LC42 and ^m LC51 ^{+ m LC52} Is 1, 2 or 3, and when there are a plurality of A ^{LC31 to} A ^LC52 and Z ^{LC31 to} Z ^LC52 , they may be the same or different. It is preferable to contain one or more compounds selected from the group consisting of the compounds represented by).
Each of R ^{LC31 to} R ^LC52 is preferably an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, and the alkenyl group has the following structure. Is most preferable to represent

（式中、環構造へは右端で結合するものとする。）
Ａ^ＬＣ３１〜Ａ^ＬＣ５２はそれぞれ独立して下記の構造が好ましく、

(In the formula, it shall be connected to the ring structure at the right end.)
The following structures are preferable for A ^{LC31 to} A ^LC52 independently of each other.

Z ^{LC31 to} Z ^LC51 are independently single-bonded, with -CH ₂ O-, -COO-, ^-OCO- , -CH ₂ CH _2- , -CF ₂ O-, -OCF _2- or -OCH _2-. preferable.
As compounds represented by the general formula (LC3), the general formula (LC4), and the general formula (LC5), the general formula (LC3-1), the general formula (LC4-1), and the general formula (LC5-1)

(In the formula, R ^{31 to} R ³³ are an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. R ^{41 to} R ⁴³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. ^represents, Z 31 ^{to Z 33} represents a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO -, - OCO -, - OCH 2 - , -CH ₂ O-, -OCF _2- or -CF ₂ O-, X ⁴¹ represents a hydrogen atom or a fluorine atom, Z ³⁴ represents a -CH _2- or an oxygen atom) It is preferable to contain at least one compound selected from the group.
In the general formulas (LC3-1) to (LC5-1), R ^{31 to} R ³³ have an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and 1 to 8 carbon atoms. It represents an alkoxy group or an alkenyloxy group having 2 to 8 carbon atoms, and preferably represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and an alkyl having 2 to 5 carbon atoms. It is more preferable to represent a group or an alkenyl group having 2 to 4 carbon atoms, further preferably to represent an alkyl group having 3 to 5 carbon atoms or an alkenyl group having 2 carbon atoms, and an alkyl group having 3 carbon atoms. It is particularly preferable to represent.

R ^{41 to} R ⁴³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. It preferably represents an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 4 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms, preferably having 3 to 8 carbon atoms. It is more preferable to represent an alkyl group of 1 to 3 or an alkoxy group having 1 to 3 carbon atoms, further preferably to represent an alkyl group having 3 carbon atoms or an alkoxy group having 2 carbon atoms, and having 2 carbon atoms. It is particularly preferable to represent an alkoxy group.
Z ³¹ to Z ³³ represents a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO -, - OCO -, - OCH 2 -, - Represents CH ₂ O-, -OCF _2- or -CF ₂ O-, but single bond, -CH ₂ CH _2- , -COO-, -OCH _2- , -CH ₂ O-, -OCF _2- or- It preferably represents CF ₂ O−, more preferably a single bond or −CH ₂ O−.
The liquid crystal composition contains 5% by mass to 50% by mass of a compound selected from the compound group represented by the general formula (LC3-1), the general formula (LC4-1), and the general formula (LC5-1). Is preferable, 5% by mass to 40% by mass is preferable, 5% by mass to 30% by mass is more preferable, 8% by mass to 27% by mass is more preferable, and 10% by mass to 25% by mass is contained. It is more preferable to contain%.

Specifically, the compound represented by the general formula (LC3-1) is preferably a compound represented by the following general formulas (LC3-11) to (LC3-15).

(In the formula, R ³¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and R ^41a represents an alkyl group having 1 to 5 carbon atoms.)
Specifically, the compound represented by the general formula (LC4-1) is preferably a compound represented by the following general formulas (LC4-11) to (LC4-14).

(In the formula, R ³² represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^42a represents an alkyl group having 1 to 5 carbon atoms, and X ⁴¹ represents a hydrogen atom or a hydrogen atom or Represents a fluorine atom.)
Specifically, the compound represented by the general formula (LC5-1) is preferably a compound represented by the following general formulas (LC5-11) to (LC5-14).

(In the formula, R ³³ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^43a represents an alkyl group having 1 to 5 carbon atoms, and Z ³⁴ represents -CH _2. -Or represents an oxygen atom.)
In the general formula (LC3-11), the general formula (LC3-13), the general formula (LC4-11), the general formula (LC4-13), the general formula (LC5-11), and the general formula (LC5-13), For R ^{31 to} R ³³ , the same embodiment in the general formula (LC3-1) to the general formula (LC5-1) is preferable. R ^{41a to} R ^41c are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms, and particularly preferably an alkyl group having 2 carbon atoms.
In the general formula (LC3-12), the general formula (LC3-14), the general formula (LC4-12), the general formula (LC4-14), the general formula (LC5-12), and the general formula (LC5-14), For R ^{31 to} R ³³ , the same embodiment in the general formula (LC3-1) to the general formula (LC5-1) is preferable. R ^{41a to} R ^41c are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 3 carbon atoms, and particularly preferably an alkyl group having 3 carbon atoms.
Among the general formulas (LC3-11) to the general formula (LC5-14), in order to increase the absolute value of the dielectric anisotropy, the general formula (LC3-11), the general formula (LC4-11), and the general formula (LC4-11) are used. Formula (LC5-11), general formula (LC3-13), general formula (LC4-13) and general formula (LC5-13) are preferable, and general formula (LC3-11), general formula (LC4-11), general formula The formula (LC5-11) is more preferable.
The liquid crystal layer in the liquid crystal display element of the present invention preferably contains one or more compounds represented by the general formulas (LC3-11) to (LC5-14), and contains one or two kinds. It is more preferable to contain one or two compounds represented by the general formula (LC3-1).

Further, as the compounds represented by the general formula (LC3), the general formula (LC4), and the general formula (LC5), the general formula (LC3-2), the general formula (LC4-2), and the general formula (LC5-2) )

(In the formula, R ^{51 to} R ⁵³ are an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. R ^{61 to} R ⁶³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. B ^{1 to} B ³ represent a fluorine-substituted 1,4-phenylene group or a trans-1,4-cyclohexylene group, Z ^{41 to} Z ⁴³ are single bonds, -CH = CH-, _{-C≡C -, - CH 2 CH 2} -, - (CH 2) 4 -, - COO -, - OCO -, - OCH 2 -, - CH 2 O -, - OCF 2 - or _-CF 2 O- X ⁴² represents a hydrogen atom or a fluorine atom, and Z ⁴⁴ represents a −CH ₂ − or an oxygen atom.)
It is preferable to contain at least one compound selected from the compound group represented by.
In the general formula (LC3-2), the general formula (LC4-2), and the general formula (LC5-2), R ^{51 to} R ⁵³ are an alkyl group having 1 to 8 carbon atoms and an alkenyl having 2 to 8 carbon atoms. It represents a group, an alkoxy group having 1 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, and preferably represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms. , It is more preferable to represent an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, and further preferably to represent an alkyl group having 3 to 5 carbon atoms or an alkenyl group having 2 carbon atoms. , It is particularly preferable to represent an alkyl group having 3 carbon atoms.

R ^{61 to} R ⁶³ represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyloxy group having 2 to 8 carbon atoms. It preferably represents an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkenyl group having 4 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms, preferably having 3 to 8 carbon atoms. It is more preferable to represent an alkyl group of 1 to 3 or an alkoxy group having 1 to 3 carbon atoms, further preferably to represent an alkyl group having 3 carbon atoms or an alkoxy group having 2 carbon atoms, and having 2 carbon atoms. It is particularly preferable to represent an alkoxy group.
B ^{31 to} B ³³ represent a 1,4-phenylene group or a trans-1,4-cyclohexylene group which may be fluorine-substituted, but an unsubstituted 1,4-phenylene group or a trans-1,4- Cyclohexylene groups are preferred, and trans-1,4-cyclohexylene groups are more preferred.
Z ⁴¹ to Z ⁴³ represents a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO -, - OCO -, - OCH 2 -, - Represents CH ₂ O-, -OCF _2- or -CF ₂ O-, but single bond, -CH ₂ CH _2- , -COO-, -OCH _2- , -CH ₂ O-, -OCF _2- or- It preferably represents CF ₂ O−, more preferably a single bond or −CH ₂ O−.
The compounds represented by the general formula (LC3-2), the general formula (LC3-3), the general formula (LC4-2), and the general formula (LC5-2) are contained in the liquid crystal composition in an amount of 10 to 60% by mass. It is preferable, but it is more preferably 20 to 50% by mass, more preferably 25 to 45% by mass, more preferably 28 to 42% by mass, and preferably 30 to 40% by mass. More preferred.

Specifically, the compound represented by the general formula (LC3-2) is preferably a compound represented by the following general formulas (LC3-21) to (LC3-29).
Further, as the compound represented by the general formula (LC3-3), the compounds represented by the following general formulas (LC3-31) to (LC3-33) are also preferable.

(In the formula, R ⁵¹ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and R ^61a represents an alkyl group having 1 to 5 carbon atoms, but the general formula (LC3-). The same embodiment as R ⁵¹ and R ⁶¹ in 2) is preferable.)

Specifically, the compound represented by the general formula (LC4-2) is preferably a compound represented by the following general formulas (LC4-21) to (LC4-26).

(In the formula, R ⁵² represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^62a represents an alkyl group having 1 to 5 carbon atoms, and X ⁴² represents a hydrogen atom or a hydrogen atom or Although it represents a fluorine atom, the same embodiment as R ⁵² and R ⁶² in the general formula (LC4-2) is preferable.)
Specifically, the compound represented by the general formula (LC5-2) is preferably a compound represented by the following general formulas (LC5-21) to (LC5-26).

(In the formula, R ⁵³ represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R ^63a represents an alkyl group having 1 to 5 carbon atoms, and W ² represents −CH _2. -Or represents an oxygen atom, but the same embodiment as R ⁵³ and R ⁶³ in the general formula (LC5-2) is preferable.)

General formula (LC3-21), general formula (LC3-22), general formula (LC3-25), general formula (LC4-21), general formula (LC4-22), general formula (LC4-25), general formula In (LC5-21), general formula (LC5-22), and general formula (LC5-25), R ^{51 to} R ⁵³ are general formula (LC3-2), general formula (LC4-2), and general formula (LC5-2). A similar embodiment in LC5-2) is preferred. R ^{61a to} R ^63a are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms, and particularly preferably an alkyl group having 2 carbon atoms.
General formula (LC3-23), general formula (LC3-24) and general formula (LC3-26), general formula (LC4-23), general formula (LC4-24) and general formula (LC4-26), general formula In (LC5-23), general formula (LC5-24) and general formula (LC5-26), R ^{51 to} R ⁵³ are general formula (LC3-2), general formula (LC4-2) and general formula (LC5-26). The same embodiment in 2) is preferred. R ^{61a to} R ^63a are preferably an alkyl group having 1 to 3 carbon atoms, more preferably an alkyl group having 1 or 3 carbon atoms, and particularly preferably an alkyl group having 3 carbon atoms.
Among the general formulas (LC3-21) to the general formula (LC5-26), in order to increase the absolute value of the dielectric anisotropy, the general formula (LC3-21), the general formula (Lc3-22) and the general formula (Lc3-22) are used. Formula (LC3-25), general formula (LC4-21), general formula (LC4-22) and general formula (LC4-25), general formula (LC5-21), general formula (LC5-22) and general formula (LC5-22) LC5-25) is preferred.
The compounds represented by the general formula (LC3-2), the general formula (Lc4-2) and the general formula (LC5-2) can contain one kind or two or more kinds, but B ^{1 to} B ³ are 1, It is preferable to contain at least one compound representing a 4-phenylene group and a compound in which B ^{1 to} B ³ represent a trans-1,4-cyclohexylene group, respectively.

In addition, other compounds represented by the general formula (LC3) include the following general formula (LC3-a) and general formula (LC3-b).

(In the formula, R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 independently represent the same meanings as R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 in the general formula (LC3), respectively, and X ^{LC3b1 to} X ^LC3b6 are Representing a hydrogen atom or a fluorine atom, but at least one combination of X ^LC3b1 and X ^LC3b2 or X ^LC3b3 and X ^LC3b4 both represents a fluorine atom, m ^LC3a1 is 1, 2 or 3, m ^LC3b1 is 0 or 1 and when there are a plurality of A ^LC31 and Z ^LC31 , they may be the same or different.) One or more compounds selected from the compound group represented by). Is preferable.
R ^LC31 and R ^LC32 independently have an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or an alkenyloxy group having 2 to 7 carbon atoms. It is preferable to represent.
A ^LC31 preferably represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group, and a 1,3-dioxane-2,5-diyl group. , 4-Phenylene group, trans-1,4-cyclohexylene group is more preferable.
Z ^LC31 is a single _{bond, -CH 2 O -, - COO} -, - OCO -, - CH 2 CH 2 - is preferred to represent, and more preferably a single bond.

As the general formula (LC3-a), it is preferable to represent the following general formula (LC3-a1).

(In the formula, R ^LC31 and R ^LC32 independently represent the same meanings as R ^LC31 and R ^LC32 in the general formula (LC3).)
R ^LC31 and R ^LC32 are each independently preferably an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, and R ^LC31 has 1 carbon atom number. More preferably, it represents an alkyl group of ^~ 7, and ^RLC32 represents an alkoxy group having 1 to 7 carbon atoms.
The general formula (LC3-b) preferably represents the following general formulas (LC3-b1) to general formulas (LC3-b12), and the general formulas (LC3-b1), general formulas (LC3-b6), and general formulas. (LC3-b8), the general formula (LC3-b11) is more preferably represented, the general formula (LC3-b1) and the general formula (LC3-b6) are further preferably represented, and the general formula (LC3-b1) is expressed. Most preferably.

(In the formula, R ^LC31 and R ^LC32 independently represent the same meanings as R ^LC31 and R ^LC32 in the general formula (LC3).)
R ^LC31 and R ^LC32 are each independently preferably an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, and R ^LC31 has 2 carbon atoms. Alternatively, it represents an alkyl group of 3, and it is more preferable that ^RLC32 represents an alkyl group having 2 carbon atoms.
The compound represented by the general formula (LC4) is preferably a compound represented by the following general formula (LC4-a) to the general formula (LC4-c), and the compound represented by the general formula (LC5) is Compounds represented by the following general formulas (LC5-a) to general formulas (LC5-c) are preferable.

^{(Wherein, R LC41,} R ^LC42 and ^{X LC41} each independently represent the same meaning as ^{R LC41, R LC42} and ^{X LC41} in the general formula ^{(LC4), R LC51} and ^{R LC52} is the general independently represents the same meaning as ^{R LC51} and ^{R LC52} in formula ^{(LC5), Z LC4a1, Z} LC4b1, Z LC4c1, Z LC5a1, Z LC5b1 and ^{Z LC5c1} each independently represent a single bond, -CH = CH -, - C≡ _{C -, - CH 2 CH 2} -, - (CH 2) 4 -, - COO -, - OCH 2 -, - CH 2 O -, - OCF 2 - or an _-CF 2 O-).
^{R LC41,} R LC42, R ^LC51 and ^{R LC52} each independently represents an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, the number alkenyl group or a carbon atom of 2 to 7 carbon atoms 2 It preferably represents an alkenyloxy group of ~ 7.
Z ^{LC4a1 to} Z ^LC5c1 each independently represent a single bond, -CH ₂ O-, ^{-COO-, -OCO-} , and -CH ₂ CH _2-, and more preferably a single bond.

The compound represented by the general formula (LC) is selected from the compounds represented by the following general formula (LC6) (excluding the compounds represented by the general formulas (LC1) to (LC5)). It is also preferable that it is one kind or two or more kinds of compounds.

In the general formula (LC6), R ^LC61 and R ^LC62 each independently represent an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group are -O-, -CH = CH-, -CO-, -OCO-, -COO- or -C so that oxygen atoms are not directly adjacent to each other. It may be substituted with ≡ C−, and one or more hydrogen atoms in the alkyl group may be optionally halogen substituted. As the compound represented by the general formula (LC6), R ^LC61 and R ^LC62 independently have an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and 2 to 7 carbon atoms. The alkenyl group of the above is preferable, and the alkoxy group most preferably represents any of the following structures.

（式中、環構造へは右端で結合するものとする。）

(In the formula, it shall be connected to the ring structure at the right end.)

In the general formula (LC6), A ^{LC61 to} A ^LC63 independently represent any of the following structures. In the structure, one or more CH ₂ CH ₂ groups in the cyclohexylene group may be substituted with -CH = CH-, -CF ₂ O-, -OCF _2- , 1,4- One or more CH groups in the phenylene group may be substituted with a nitrogen atom.

As the compound represented by the general formula (LC6), A ^{LC61 to} A ^LC63 each independently preferably have any of the following structures.

Formula (LC6) ^{in, Z LC61} and ^{Z LC62} each independently represent a single bond, -CH = CH -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - COO- _{, -OCH 2 -, - CH 2} O -, - OCF 2 - or _-CF 2 O-a represents, MLC61 represents 0-3. Examples of the compound represented by the general formula ^{(LC6), Z LC61} and ^{Z LC62} each independently represent a single _{bond, -CH 2 CH 2 -, -} COO -, - OCH 2 -, - CH 2 O -, - OCF 2 -Or -CF ₂ O- is preferable.

The compound represented by the general formula (LC6) shall be one or more compounds selected from the group consisting of compounds represented by the following general formulas (LC6-a) to general formula (LC6-v). Is preferable. In the formulas of the general formula (LC6-a1) to the general formula (LC6-p1), R ^LC61 and R ^LC62 independently have an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, and carbon. It represents an alkenyl group having 2 to 7 atoms or an alkenyloxy group having 2 to 7 carbon atoms.

[Polymerizable compound]
The polymer or copolymer according to the present invention contains a polymer or copolymer obtained by polymerizing one or more of the polymerizable compounds represented by the following general formula (X1b).

（式中、Ａ^８は水素原子又はメチル基を表し、６員環Ｔ^１、Ｔ^２及びＴ^３はそれぞれ独立して

(In the formula, A ⁸ represents a hydrogen atom or a methyl group, and the 6-membered rings T ¹ , T ² and T ³ are independent of each other.

(However, m represents an integer from 1 to 4).
q represents 0 or 1 and represents
Y ¹ and Y ² are independently single-coupled, -CH ₂ CH _2- , -CH ₂ O-, -OCH _2- , -COO-, -OCO-, -C≡C-, -CH = CH- _{, -CF = CF -, - OCF} 2 -, - CF 2 O -, - (CH 2) 4 -, - CH 2 CH 2 O -, - OCH 2 CH 2 -, - CH = CHCH 2 CH 2 -, _{-CH 2 CH 2 CH = CH -} , - COO-CH 2 CH 2 -, - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO- or represents a _-CH 2 _CH 2 -OCO-, Y ¹ and at least one ^{Y 2} is _{-COO-CH 2 CH 2 -,} - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO- or _-CH 2 _CH 2 -OCO- represent, q is 0 when referring to, ^{Y 1} is _{-COO-CH 2 CH 2 -,} - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO- or _-CH 2 _CH 2 -OCO- represent,
Y ³ and Y ⁴ are independently single-bonded, and alkylene groups having 1 to 12 carbon atoms (one or two or more methylene groups in the alkylene group do not directly bond oxygen atoms to each other. They may be independently substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkylene group are independently a fluorine atom and a methyl group, respectively. Alternatively, it may be substituted with an ethyl group.)
B ⁸ represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group having 1 to 14 carbon atoms, and the terminal −CH _{3 of the} alkyl group may be replaced with an acryloyl group or a methacryloyl group. )
It is preferable to use a polymerizable compound having at least two or more polymerizable functional groups in the molecule. Among them, general formula (I)

（式中、Ｗ^１及びＷ^２はそれぞれ独立的に単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、Ｙ^１及びＹ^２はそれぞれ独立的に−ＣＯＯ−又は−ＯＣＯ−を表し、ｐ及びｑはそれぞれ独立的に２〜１３の整数を表すが、式中に存在する１，４−フェニレン基は炭素原子数１〜７のアルキル基、アルコキシ基、アルカノイル基、シアノ基又はハロゲン原子で一つ以上置換されていても良い。）で表される化合物が好ましい。
一般式（Ｉ）において、Ｗ^１及びＷ^２は−Ｏ−を表し、Ｙ^１は−ＣＯＯ−を表し、Ｙ^２は−ＯＣＯ−を表し、ｐ及びｑはそれぞれ独立的に３〜１２の整数である化合物がより好ましく、ｐ＝ｑ＝６又はｐ＝ｑ＝３である化合物が好ましい。
一般式（Ｉ）で表される化合物はさらに具体的には、一般式（Ｉ−１）〜一般式（Ｉ―８）で表される化合物を挙げることができる。

(In the equation, W ¹ and W ² independently represent single bonds, -O-, -COO- or -OCO-, and Y ¹ and Y ² independently represent -COO- or -OCO-, respectively. , P and q each independently represent an integer of 2 to 13, but the 1,4-phenylene group present in the formula is an alkyl group, an alkoxy group, an alkanoyl group, a cyano group or a halogen having 1 to 7 carbon atoms. A compound represented by (1 or more atoms may be substituted) is preferable.
In general formula (I), W ¹ and W ² represent −O−, Y ¹ represents −COO−, Y ² represents −OCO−, and p and q are independently integers of 3 to 12, respectively. The compound is more preferable, and the compound having p = q = 6 or p = q = 3 is preferable.
More specifically, the compound represented by the general formula (I) can be mentioned as a compound represented by the general formulas (I-1) to (I-8).

(In the formula, p and q have the same meaning in the general formula (I).)
In the general formulas (I-1) to (I-8), p and q are preferably integers of 3 to 13 independently.
The compound represented by the general formula (I) is preferably contained in two or more kinds for the purpose of stably expressing the liquid crystal phase and for the purpose of avoiding the precipitation of the crystal phase, and the general formulas (I-1) to (I-1) to (general formulas) In I-8), it is particularly preferable to contain two or more compounds having p = q = 6 or p = q = 3.
In addition, general formula (II)

（式中、Ｗ^３及びＷ^４はそれぞれ独立的に単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−を表し、Ｙ^３は−ＣＯＯ−又は−ＯＣＯ−を表し、ｒ及びｓはそれぞれ独立的に２〜１３の整数を表すが、式中に存在する１，４−フェニレン基は炭素原子数１〜７のアルキル基、アルコキシ基、アルカノイル基、シアノ基又はハロゲン原子で一つ以上置換されていても良い。）で表される化合物を含有させることも好ましい。一般式（ＩＩ）のような２官能液晶性アクリレートを用いると、室温でスメクチックA相を呈する組成物を容易に得ることができる。一般式（ＩＩ）で表される化合物は、さらに具体的には、一般式（ＩＩ−１）〜一般式（ＩＩ―１０）で表される化合物を挙げることができる。

(In the equation, W ³ and W ⁴ independently represent single bonds, -O-, -COO- or -OCO-, Y ³ represents -COO- or -OCO-, and r and s are independent, respectively. The 1,4-phenylene group existing in the formula is substituted with one or more alkyl groups, alkoxy groups, alkanoyl groups, cyano groups or halogen atoms having 1 to 7 carbon atoms. It is also preferable to contain the compound represented by). By using a bifunctional liquid crystal acrylate as in the general formula (II), a composition exhibiting a smectic A phase at room temperature can be easily obtained. Specific examples of the compound represented by the general formula (II) include compounds represented by the general formulas (II-1) to (II-10).

（式中、ｒ及びｓは一般式（ＩＩ）における意味と同じ。）
また、以下に示す化合物も好ましい。

(In the formula, r and s have the same meaning in the general formula (II).)
The compounds shown below are also preferable.

（式中、Ｒ^３４は、水素原子又はメチル基を表し、ｅ及びｆは一般式（Ｘ１ｂ）におけるＹ^３及びＹ^４と同じ意味を表す。）

(In the formula, R ³⁴ represents a hydrogen atom or a methyl group, and e and f have the same meanings as Y ³ and Y ⁴ in the general formula (X1b).)

The polymer or copolymer according to the present invention may contain a polymer or copolymer of a polymerizable compound other than the polymerizable compound represented by the general formula (X1b). Examples of such a polymerizable compound include a monofunctional polymerizable compound having one reactive group and a polyfunctional polymerizable compound having two or more reactive groups such as bifunctional or trifunctional. Be done. The polymerizable compound having a reactive group may or may not contain a mesogenic moiety.
In the polymerizable compound having a reactive group, the reactive group is preferably a substituent having a polymerizable property with light. In particular, when the vertically oriented film is produced by thermal polymerization, the reaction of the polymerizable compound having a reactive group can be suppressed during the thermal polymerization of the vertically aligned film material, so that the reactive group has polymerizability by light. Substituents are particularly preferred.
Of these, the compound represented by the following general formula (P) is preferable (however, the compound represented by the general formula (X1b) is excluded).

（上記一般式（Ｐ）中、Ｚ^ｐ１は、フッ素原子、シアノ基、水素原子、水素原子がハロゲン原子に置換されていてもよい炭素原子数１〜１５のアルキル基、水素原子がハロゲン原子に置換されていてもよい炭素原子数１〜１５のアルコキシ基、水素原子がハロゲン原子に置換されていてもよい炭素原子数１〜１５のアルケニル基、水素原子がハロゲン原子に置換されていてもよい炭素原子数１〜１５のアルケニルオキシ基又は−Ｓｐ^ｐ２−Ｒ^ｐ２を表し、
Ｒ^ｐ１及びＲ^ｐ２はそれぞれ独立して以下の式（Ｒ−Ｉ）から式（Ｒ−ＩＸ）：

(In the above general formula (P), Z ^p1 is an alkyl group having 1 to 15 carbon atoms in which a fluorine atom, a cyano group, a hydrogen atom, or a hydrogen atom may be replaced with a halogen atom, and a hydrogen atom is a halogen atom. An alkoxy group having 1 to 15 carbon atoms which may be substituted, an alkenyl group having 1 to 15 carbon atoms whose hydrogen atom may be substituted by a halogen atom, and a hydrogen atom may be substituted by a halogen atom. Represents an alkenyloxy group having 1 to 15 carbon atoms or -Sp ^p2 -R ^p2 .
R ^p1 and R ^p2 are independently ^derived from the following equations (RI) to (R-IX):

のいずれかを表し、前記式（Ｒ−Ｉ）〜（Ｒ−ＩＸ）中、Ｒ^２〜Ｒ^６はお互いに独立して、水素原子、炭素原子数１〜５個のアルキル基または炭素原子数１〜５個のハロゲン化アルキル基であり、Ｗは単結合、−Ｏ−またはメチレン基であり、Ｔは単結合または−ＣＯＯ−であり、ｐ、ｔおよびｑはそれぞれ独立して、０、１または２を表し、
Ｓｐ^ｐ１及びＳｐ^ｐ２はスペーサー基を表し、Ｓｐ^ｐ1及びＳｐ^ｐ２はそれぞれ独立して、単結合、炭素原子数１〜１２のアルキレン基又は−Ｏ−（ＣＨ_２）_ｓ−（式中、ｓは１〜１１の整数を表し、酸素原子は芳香環に結合するものとする。）を表し
Ｌ^ｐ１及びＬ^ｐ２はそれぞれ独立して、単結合、−Ｏ−、−Ｓ−、−ＣＨ_２−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯ−、−Ｃ_２Ｈ_４−、−ＣＯＯ−、−ＯＣＯ−、−ＯＣＯＯＣＨ_２−、−ＣＨ_２ＯＣＯＯ−、−ＯＣＨ_２ＣＨ_２Ｏ−、−ＣＯ−ＮＲ^ａ−、−ＮＲ^ａ−ＣＯ−、−ＳＣＨ_２−、−ＣＨ_２Ｓ−、−ＣＨ＝ＣＲ^ａ−ＣＯＯ−、−ＣＨ＝ＣＲ^ａ−ＯＣＯ−、−ＣＯＯ−ＣＲ^ａ＝ＣＨ−、−ＯＣＯ−ＣＲ^ａ＝ＣＨ−、−ＣＯＯ−ＣＲ^ａ＝ＣＨ−ＣＯＯ−、−ＣＯＯ−ＣＲ^ａ＝ＣＨ−ＯＣＯ−、−ＯＣＯ−ＣＲ^ａ＝ＣＨ−ＣＯＯ−、−ＯＣＯ−ＣＲ^ａ＝ＣＨ−ＯＣＯ−、−（ＣＨ_２）_ｚ−Ｃ（＝Ｏ）−Ｏ−、−（ＣＨ_２）ｚ−Ｏ−（Ｃ＝Ｏ）−、−Ｏ−（Ｃ＝Ｏ）−（ＣＨ_２）ｚ−、−（Ｃ＝Ｏ）−Ｏ−（ＣＨ_２）ｚ−、−ＣＨ＝ＣＨ−、−ＣＦ＝ＣＦ−、−ＣＦ＝ＣＨ−、−ＣＨ＝ＣＦ−、−ＣＦ_２−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＦ_２ＣＨ_２−、−ＣＨ_２ＣＦ_２−、−ＣＦ_２ＣＦ_２−又は−Ｃ≡Ｃ−（式中、Ｒ^ａはそれぞれ独立して水素原子又は炭素原子数１〜４のアルキル基を表し、前記式中、ｚは１〜４の整数を表す。）を表し、
Ｍ^ｐ２は、１，４−フェニレン基、１，４−シクロヘキシレン基、アントラセン−２，６−ジイル基、フェナントレン−２，７−ジイル基、ピリジン−２，５−ジイル基、ピリミジン−２，５−ジイル基、ナフタレン−２，６−ジイル基、インダン−２，５−ジイル基、１，２，３，４−テトラヒドロナフタレン−２，６−ジイル基又は１，３−ジオキサン−２，５−ジイル基を表すが、Ｍ^ｐ２は無置換であるか又は炭素原子数１〜１２のアルキル基、炭素原子数１〜１２のハロゲン化アルキル基、炭素原子数１〜１２のアルコキシ基、炭素原子数１〜１２のハロゲン化アルコキシ基、ハロゲン原子、シアノ基、ニトロ基又は−Ｒ^ｐ１で置換されていても良く、
Ｍ^ｐ１は以下の式（ｉ−１１）〜（ｉｘ−１１）：

Represents either, in the formula (R-I) ~ (R -IX), R 2 ~R 6 are independently of each other, hydrogen atom, the number 1-5 alkyl group or a number of carbon atoms of carbon atoms 1 to 5 alkyl halide groups, W is a single bond, -O- or methylene group, T is a single bond or -COO-, p, t and q are independently 0, respectively. Represents 1 or 2
Sp ^p1 and Sp ^p2 represent spacer groups, and Sp ^p1 and Sp ^p2 are independently single bonds, alkylene groups having 1 to 12 carbon atoms, or —O— (CH ₂ ) _s − (in the formula, s is). It represents an integer of 1 to 11 and the oxygen atom is bound to the aromatic ring.) L ^p1 and L ^p2 are independently single-bonded, -O-, -S-, -CH _2- , respectively. _{-OCH 2 -, - CH 2 O} -, - CO -, - C 2 H 4 -, - COO -, - OCO -, - OCOOCH 2 -, - CH 2 OCOO -, - OCH 2 CH 2 O -, - CO-NR ^a- , -NR ^a- CO-, -SCH _2- , -CH ₂ S-, -CH = CR ^a- COO-, -CH = CR ^a- OCO-, -COO-CR ^a = CH- ^{, -OCO-CR a = CH -} , - COO-CR a = CH-COO -, - COO-CR a = CH-OCO -, - OCO-CR a = CH-COO -, - OCO-CR a = CH -OCO-,-(CH ₂ ) _z- C (= O) -O-,-(CH ₂ ) z-O- (C = O)-, -O- (C = O)-(CH ₂ ) z -,-(C = O) -O- (CH ₂ ) z-, -CH = CH-, -CF = CF-, -CF = CH-, -CH = CF-, -CF _2- , -CF ₂ O-, -OCF _2- , -CF ₂ CH _2- , -CH ₂ CF _2- , -CF ₂ CF _2- or -C ≡ C- (In the formula, ^Ra is an independent hydrogen atom or carbon atom, respectively. Represents an alkyl group of numbers 1 to 4, and in the above formula, z represents an integer of 1 to 4).
M ^p2 is 1,4-phenylene group, 1,4-cyclohexylene group, anthracene-2,6-diyl group, phenanthrene-2,7-diyl group, pyridine-2,5-diyl group, pyrimidin-2, 5-diyl group, naphthalene-2,6-diyl group, indan-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or 1,3-dioxane-2,5 -Representing a diyl group, M ^p2 is unsubstituted or an alkyl group having 1 to 12 carbon atoms, an alkyl halide group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and a carbon atom. It may be substituted with a halogenated alkoxy group of numbers 1 to 12, a halogen atom, a cyano group, a nitro group or -R ^p1 .
M ^p1 is the following equations (i-11) to (ix-11):

（式中、★でＳｐ^ｐ１と結合し、★★でＬ^ｐ１若しくはＬ^ｐ２と結合する。）のいずれかを表し、
Ｍ^ｐ３は以下の式（ｉ−１３）〜（ｉｘ−１３）：

(In the formula, ★ binds to Sp ^p1 and ★★ binds to L ^p1 or L ^p2 .)
M ^p3 is expressed by the following equations (i-13) to (ix-13):

（式中、★でＺ^ｐ１と結合し、★★でＬ^ｐ２と結合する。）のいずれかを表し、
ｍ^ｐ２〜ｍ^ｐ４はそれぞれ独立して、０、１、２又は３を表し、ｍ^ｐ１及びｍ^ｐ５はそれぞれ独立して１、２又は３を表すが、Ｚ^ｐ１が複数存在する場合にはそれらは同一であっても異なっていてもよく、Ｒ^ｐ１が複数存在する場合にはそれらは同一であっても異なっていてもよく、Ｒ^ｐ２が複数存在する場合にはそれらは同一であっても異なっていてもよく、Ｓｐ^ｐ１が複数存在する場合にはそれらは同一であっても異なっていてもよく、Ｓｐ^ｐ２が複数存在する場合にはそれらは同一であっても異なっていてもよく、Ｌ^ｐ１が複数存在する場合にはそれらは同一であっても異なっていてもよく、Ｍ^ｐ２が複数存在する場合にはそれらは同一であっても異なっていてもよい。）

(In the formula, ★ is combined with Z ^p1 and ★★ is combined with L ^p2 .)
m ^{p2 to} m ^p4 independently represent 0, 1, 2 or 3, and m ^p1 and m ^p5 independently represent 1, 2 or 3, respectively, but when there are a plurality of Z ^p1 , they. ^May be the same or different, if there are a plurality of R ^p1 , they may be the same or different, and if there are a plurality of R ^p2 , they may be the same. They may be different, they may be the same or different when there are a plurality of Sp ^p1, and they may be the same or different when there are a plurality of Sp ^p2 . When there are a plurality of L ^p1 , they may be the same or different, and when there are a plurality of M ^p2 , they may be the same or different. )

Moreover, it is preferable that the polymerizable compound is contained in one kind or two or more kinds.
In the general formula (P), Z ^p1 is preferably −Sp ^p2- R ^p2 , and R ¹¹ and R ¹² are independently one of the formulas (R-1) to (R-3). Is preferable.
Further, in the general formula (P), it is preferable that m ^p1 + m ^p5 is 2 or more.
Further, in the general formula ^{(P), L p1} represents a single _{bond, -OCH 2 -, - CH 2} O -, - CO -, - C 2 H 4 -, - COO -, - OCO -, - COOC 2 _{H 4 -, - OCOC 2 H} 4 -, - C 2 H 4 OCO -, - C 2 H 4 COO -, - CH = CH -, - CF 2 -, - CF 2 O -, - (CH 2) z -C (= O) -O-,-(CH ₂ ) z-O- (C = O)-, -O- (C = O)-(CH ₂ ) z-, -CH = CH-COO-, -COO-CH = CH-, -OCOCH = CH-,-(C = O) -O- (CH ₂ ) z-, -OCF _2- or -C≡C-, where L ^p2 is -OCH _{2 CH 2 O -, - COOC 2} H 4 -, - OCOC 2 H 4 -, - (CH 2) z -C (= O) -O -, - (CH 2) z-O- (C = O) - , -O- (C = O)-(CH ₂ ) z-,-(C = O) -O- (CH ₂ ) z-, -CH = CH-COO-, -COO-CH = CH-,- OCOCH = CH-, -C ₂ H ₄ OCO- or -C ₂ H ₄ COO-, and z in the above formula is preferably an integer of 1 to 4.
Further, at least one of L ^p1 and L ^p2 of the general formula (P) is − (CH ₂ ) _z −C (= O) −O−, − (CH ₂ ) z−O− (C = O). It is preferably at least one selected from the group consisting of − and −O− (C = O) − (CH ₂ ) z−, − (C = O) −O− (CH ₂ ) z−.
Further, in the general formula (P), R ^p1 and R ^p2 are independently ^derived from the following formulas (R-1) to formulas (R-15):

のいずれかがより好ましい。

Is more preferable.

Further, m ^p3 of the general formula (P) represents 0, 1, 2 or 3, and when m ^p2 is 1, L ^p1 is a single bond, and when m ^p2 is 2 or 3, there are a plurality of L ^p1 . At least one is preferably a single bond.
Further, m ^p3 of the general formula (P) represents 0, 1, 2 or 3, and when m ^p3 is 1, M ^p2 is a 1,4-phenylene group, and when m ^p3 is 2 or 3, there are a plurality of them. ^{M p2} adjacent to ^{M p1} through at least ^{L p1} of ^{M p2} which is preferably a 1,4-phenylene group.
Further, the ^{m p3} of the general formula (P) represents 0, 1, 2 or ^3, at least one of ^{M p2,} is one or more fluorine are substituted 1,4-phenylene group Is preferable.
Further, m ^p4 of the general formula (P) represents 0, 1, 2 or 3, and at least one of M ^p3 is a 1,4-phenylene group substituted with one or more fluorines. Is preferable.
Further, as the spacer group (Sp ^p1 , Sp ^p2 , Sp ^p4 ) in the general formula (P), a single bond, -OCH ₂ -,-(CH ₂ ) _z O-, -CO-, -C ₂ H _{4 -, - COO -, - OCO} -, - COOC 2 H 4 -, - OCOC 2 H 4 -, - (CH 2) z -, - C 2 H 4 OCO -, - C 2 H 4 COO -, - CH = CH-, -CF _2- , -CF ₂ O-,-(CH ₂ ) _z- C (= O) -O-,-(CH ₂ ) _z- O- (C = O)-, -O- _{(C = O) - (CH} 2) z -, - (C = O) -O- (CH 2) z -, - O- (CH 2) z -O -, - OCF 2 -, - CH = CH -COO-, -COO-CH = CH-, -OCOCH = CH- or -C≡C- are preferable, and Z is preferably an integer of 1 or more and 10 or less.

The polymerizable compound of the general formula (P) is a group consisting of compounds represented by the general formula (P-a), the general formula (P-b), the general formula (P-c) and the general formula (P-d). It is preferable that the compound is at least one selected from the above (however, the compound represented by the general formula (X1b) is excluded).

上記一般式（Ｐ−ａ）〜一般式（Ｐ−ｄ）中、Ｒ^ｐ１及びＲ^ｐ２はそれぞれ独立して以下の式（Ｒ−Ｉ）から式（Ｒ−ＩＸ）：

In the general formulas (P-a) to (P-d), R ^p1 and R ^p2 are independently ^derived from the following formulas (RI) to formula (R-IX):

のいずれかを表し、前記式（Ｒ−Ｉ）〜（Ｒ−ＩＸ）中、Ｒ^２〜Ｒ^６はお互いに独立して、水素原子、炭素原子数１〜５個のアルキル基または炭素原子数１〜５個のハロゲン化アルキル基であり、Ｗは単結合、−Ｏ−またはメチレン基であり、Ｔは単結合または−ＣＯＯ−であり、ｐ、ｔおよびｑはそれぞれ独立して、０、１または２を表し、
環Ａおよび環Ｂはそれぞれ独立して、１，４−フェニレン基、１，４−シクロヘキシレン基、アントラセン−２，６−ジイル基、フェナントレン−２，７−ジイル基、ピリジン−２，５−ジイル基、ピリミジン−２，５−ジイル基、ナフタレン−２，６−ジイル基、インダン−２，５−ジイル基、１，２，３，４−テトラヒドロナフタレン−２，６−ジイル基又は１，３−ジオキサン−２，５−ジイル基を表すが、無置換であるか又は炭素原子数１〜１２のアルキル基、炭素原子数１〜１２のハロゲン化アルキル基、炭素原子数１〜１２のアルコキシ基、炭素原子数１〜１２のハロゲン化アルコキシ基、ハロゲン原子、シアノ基、ニトロ基又は−Ｒ^ｐ１で置換されていていることが好ましく、
環Ｃは以下の式（ｃ−ｉ）〜（ｃ−ｉｘ）：

Represents either, in the formula (R-I) ~ (R -IX), R 2 ~R 6 are independently of each other, hydrogen atom, the number 1-5 alkyl group or a number of carbon atoms of carbon atoms 1 to 5 alkyl halide groups, W is a single bond, -O- or methylene group, T is a single bond or -COO-, p, t and q are independently 0, respectively. Represents 1 or 2
Rings A and B are independently 1,4-phenylene group, 1,4-cyclohexylene group, anthracene-2,6-diyl group, phenanthrene-2,7-diyl group, pyridine-2,5- Diyl group, pyrimidin-2,5-diyl group, naphthalene-2,6-diyl group, indan-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or 1, Represents a 3-dioxane-2,5-diyl group, which is unsubstituted or an alkyl group having 1 to 12 carbon atoms, an alkyl halide group having 1 to 12 carbon atoms, and an alkoxy having 1 to 12 carbon atoms. It is preferably substituted with a group, a halogenated alkoxy group having 1 to 12 carbon atoms, a halogen atom, a cyano group, a nitro group or −R ^p1 .
Ring C has the following equations (ci) to (c-ix):

（式中、★でＳｐ^ｐ１と結合し、★★でＬ^ｐ５若しくはＬ^ｐ６と結合する。）のいずれかを表し、
Ｓｐ^ｐ１及びＳｐ^ｐ４はスペーサー基を表し、Ｘ^ｐ１〜Ｘ^ｐ４は、それぞれ独立して、水素原子またはハロゲン原子を表すことが好ましく、
Ｌ^ｐ４、Ｌ^ｐ５およびＬ^ｐ６はそれぞれ独立して、単結合、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯ−、−Ｃ_２Ｈ_４−、−ＣＯＯ−、−ＯＣＯ−、−ＣＯＯＣ_２Ｈ_４−、−ＯＣＯＣ_２Ｈ_４−、−Ｃ_２Ｈ_４ＯＣＯ−、−Ｃ_２Ｈ_４ＣＯＯ−、−ＣＨ＝ＣＨ−、−ＣＦ_２−、−ＣＦ_２Ｏ−、−（ＣＨ_２）_ｚ−Ｃ（＝Ｏ）−Ｏ−、−（ＣＨ_２）_ｚ−Ｏ−（Ｃ＝Ｏ）−、−Ｏ−（Ｃ＝Ｏ）−（ＣＨ_２）_ｚ−、−（Ｃ＝Ｏ）−Ｏ−（ＣＨ_２）_ｚ−、−Ｏ−（ＣＨ_２）_ｚ−Ｏ−、−ＯＣＦ_２−、−ＣＨ＝ＣＨＣＯＯ−、−ＣＯＯＣＨ＝ＣＨ−、−ＯＣＯＣＨ＝ＣＨ−又は−Ｃ≡Ｃ−であることが好ましく、前記式中のｚは、１〜４の整数であることが好ましい。

(In the formula, ★ binds to Sp ^p1 and ★★ binds to L ^p5 or L ^p6 .)
It is preferable that Sp ^p1 and Sp ^p4 represent a spacer group, and X ^{p1 to} X ^p4 each independently represent a hydrogen atom or a halogen atom.
L ^{p4, L p5} and ^{L p6} each independently represent a single _{bond, -OCH 2 -, - CH 2} O -, - CO -, - C 2 H 4 -, - COO -, - OCO -, - COOC 2 _{H 4 -, - OCOC 2 H} 4 -, - C 2 H 4 OCO -, - C 2 H 4 COO -, - CH = CH -, - CF 2 -, - CF 2 O -, - (CH 2) z -C (= O) -O-,-(CH ₂ ) _z- O- (C = O)-, -O- (C = O)-(CH ₂ ) _z -,-(C = O) -O -(CH ₂ ) _z- , -O- (CH ₂ ) _z- O-, -OCF _2- , -CH = CHCOO-, -COOCH = CH-, -OCOCH = CH- or -C≡C-. It is preferable that z in the above formula is an integer of 1 to 4.

L ^p3 is preferably -CH = CHCOO-, -COOCH = CH- or -OCOCH = CH-.
In the compound represented by the general formula (P-a), it is preferable that m ^p6 and m ^p7 independently represent 0, 1, 2 or 3, respectively. Further, it is more preferable that m ^p6 + m ^p7 = 2 to 5.
In the compound represented by the above general formula (Pd), m ^p12 and m ^p15 preferably independently represent 1, 2 or 3, respectively, and m ^p13 preferably represents 0, 1, 2 or 3. m ^p14 preferably represents 0 or 1. Further, it is more preferable that m ^p12 + m ^p15 = 2 to 5. When there are a plurality of R ^p1 , they may be the same or different, and when there are a plurality of R ^p1 , they may be the same or different, and there are a plurality of R ^p2. In some cases, they may be the same or different, if there are multiple Sp ^p1 , they may be the same or different, and if there are multiple Sp ^p4 , they may be the same. They may be the same or different when there are a plurality of L ^p4 and L ^p5, and they may be the same when there are a plurality of rings A to C. It may be different.

The preferable structures of the compounds represented by the general formulas (Pa) to (Pd) are illustrated below.
Preferred examples of the compound represented by the general formula (P-a) include polymerizable compounds represented by the following formulas (P-a-1) to (P-a-31).

一般式（Ｐ−ｂ）で表される化合物の好ましい例として、下記式（Ｐ−ｂ−１）〜式（Ｐ−ｂ−３４）で表される重合性化合物が挙げられる。

Preferred examples of the compound represented by the general formula (P-b) include polymerizable compounds represented by the following formulas (P-b-1) to (P-b-34).

一般式（Ｐ−ｃ）で表される化合物の好ましい例として、下記式（Ｐ−ｃ−１）〜式（Ｐ−ｃ−５２）で表される重合性化合物が挙げられる。

Preferred examples of the compound represented by the general formula (P-c) include polymerizable compounds represented by the following formulas (P-c-1) to (P-c-52).

一般式（Ｐ−ｄ）で表される化合物は、以下の一般式（Ｐ−ｄ’）で表される化合物が好ましい。

The compound represented by the general formula (Pd) is preferably a compound represented by the following general formula (Pd').

（上記一般式（Ｐ−ｄ’）で表される化合物において、ｍ^ｐ１０は、２または３を表すことがより好ましい。その他の記号は上記一般式（ｐ−ｄ）と同一なので省略する。）
一般式（Ｐ−ｄ）で表される化合物の好ましい例として、下記式（Ｐ−ｄ−１）〜式（Ｐ−ｄ−３１）で表される重合性化合物が挙げられる。

(In the compound represented by the above general formula (Pd'), ^mp10 more preferably represents 2 or 3. Other symbols are the same as the above general formula (pd) and are omitted.)
Preferred examples of the compound represented by the general formula (Pd) include polymerizable compounds represented by the following formulas (Pd-1) to (Pd-31).

The "alkyl group having 1 to 15 carbon atoms" in the general formula (P) is preferably a linear or branched alkyl group, and more preferably a linear alkyl group. Further, in the above general formula (1), R ¹ and R ² are independently alkyl groups having 1 to 15 carbon atoms, and R ¹ and R ² are independent of each other and have 1 to 1 carbon atoms. Eight alkyl groups are preferable, and alkyl groups having 1 to 6 carbon atoms are more preferable.
Examples of the "alkyl group having 1 to 15 carbon atoms" in the general formula (P) include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a t-butyl group, and a 3-pentyl group. , Isopentyl group, neopentyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, pentadecyl group and the like. In the present specification, examples of alkyl groups are common, and are appropriately selected from the above examples depending on the number of carbon atoms of each alkyl group.
The example of "alkoxy group having 1 to 15 carbon atoms" in the general formula (P) preferably exists at a position where at least one oxygen atom in the substituent is directly bonded to the ring structure, and is preferably a methoxy group. , Ethoxy group, propoxy group (n-propoxy group, i-propoxy group), butoxy group, pentyloxy group, octyloxy group and decyloxy group are more preferable. In the present specification, examples of alkoxy groups are common, and are appropriately selected from the above examples according to the number of carbon atoms of each alkoxy group.
Examples of the "alkenyl group having 2 to 15 carbon atoms" in the general formula (P) are vinyl group, allyl group, 1-propenyl group, isopropenyl group, 2-butenyl group, 3-butenyl group, 1,3. -Butadienyl group, 2-pentenyl group, 3-pentenyl group, 2-hexenyl group and the like can be mentioned. More preferable alkenyl groups include the following formulas (i) (vinyl group), formula (ii) (1-propenyl group), formula (iii) (3-butenyl group) and formula (iv) (3-). Pentenyl group):

（上記式（ｉ）〜（ｉｖ）中、＊は環構造への結合部位を示す。）
で表されるが、本願発明の液晶組成物が重合性モノマーを含有する場合は、式（ｉｉ）および式（ｉｖ）で表される構造が好ましく、式（ｉｉ）で表される構造がより好ましい。なお、本明細書中において、アルケニル基の例は共通であり、各々のアルケニル基の炭素原子数の数によって適宜上記例示から選択される。
また、低分子液晶との溶解性を高めて結晶化を抑制するのに好ましい単官能性の反応基を有する重合性化合物としては、下記一般式（ＶＩ）で表される重合性化合物が挙げられる（但し、一般式（Ｘ１ｂ）で表される化合物を除く。）。

(In the above formulas (i) to (iv), * indicates a binding site to the ring structure.)
However, when the liquid crystal composition of the present invention contains a polymerizable monomer, the structures represented by the formulas (ii) and (iv) are preferable, and the structure represented by the formula (ii) is more preferable. preferable. In the present specification, examples of alkenyl groups are common, and are appropriately selected from the above examples according to the number of carbon atoms of each alkenyl group.
Further, examples of the polymerizable compound having a monofunctional reactive group preferable for increasing the solubility with a low molecular weight liquid crystal and suppressing crystallization include a polymerizable compound represented by the following general formula (VI). (However, the compound represented by the general formula (X1b) is excluded.).

(In the formula, X ³ represents a hydrogen atom or a methyl group, Sp ³ is a single bond, an alkylene group having 1 to 12 carbon atoms or −O− (CH ₂ ) _t − (in the formula, t is 2 to 2). It represents an integer of 11, and the oxygen atom is bound to the aromatic ring.), Where V is a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent ring having 5 to 30 carbon atoms. Although it represents a substituent, the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which oxygen atoms are not adjacent to each other, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group is an oxygen atom). May be substituted with an oxygen atom in a non-adjacent range) or with a cyclic substituent, and W represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 15 carbon atoms. In all 1,4-phenylene groups of, any hydrogen atom may be substituted with -CH ₃ , -OCH ₃ , fluorine atom, or cyano group.)

In the above general formula (VI), X ³ represents a hydrogen atom or a methyl group, but a hydrogen atom is preferable when the reaction rate is important, and a methyl group is used when reducing the reaction residual amount is important. preferable.
In the above general formula (VI), Sp ³ represents a single bond, an alkylene group having 1 to 12 carbon atoms or −O− (CH ₂ ) _t − (in the formula, t represents an integer of 2 to 11 and an oxygen atom. Indicates that the bond is attached to an aromatic ring.) However, since the length of the carbon chain affects Tg, when the content of the polymerizable compound is less than 10% by weight, it is preferably not so long, and it is simply simple. An alkylene group having 1 to 5 carbon atoms is preferable, and a single bond or an alkylene group having 1 to 3 carbon atoms is more preferable when the content of the polymerizable compound is less than 6% by weight. When the content of the polymerizable compound is 10% by weight or more, an alkylene group having 5 to 10 carbon atoms is preferable. Also, when Sp ³ represents −O− (CH ₂ ) _t −, t is preferably 1 to 5, more preferably 1-3. Furthermore, it is preferable to use a mixture of a plurality of number of carbon atoms of Sp ³ are different polymerizable compounds such that the desired pre-tilt angle as needed so affects the pretilt angle can be obtained carbon atoms.
In the above general formula (VI), V represents a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and is an alkylene group in the polyvalent alkylene group. May be substituted with an oxygen atom in a range in which the oxygen atom is not adjacent, or an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group may be substituted in the range in which the oxygen atom is not adjacent). ) Or may be substituted with a cyclic substituent, preferably substituted with two or more cyclic substituents.

More specifically, the polymerizable compound represented by the general formula (VI) has the general formula (X1a).

(In the formula, A ¹ represents a hydrogen atom or a methyl group.
A ² is a single bond or an alkylene group having 1 to 8 carbon atoms (one or two or more methylene groups in the alkylene group are independently oxygen atoms, assuming that oxygen atoms are not directly bonded to each other. It may be substituted with −CO−, −COO− or −OCO−, and one or more hydrogen atoms in the alkylene group are independently substituted with a fluorine atom, a methyl group or an ethyl group, respectively. May be),
A ³ and A ⁶ are independently hydrogen atoms, halogen atoms, or alkyl groups having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl groups do not directly bond oxygen atoms to each other. As such, they may be independently substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkyl group are independently halogens. It may be substituted with an atom or an alkyl group having 1 to 17 carbon atoms.)
A ⁴ and A ⁷ are independently hydrogen atoms, halogen atoms, or alkyl groups having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl groups do not directly bond oxygen atoms to each other. As such, they may be independently substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkyl group are independently halogens. It may be substituted with an atom or an alkyl group having 1 to 9 carbon atoms.)
p represents 0 to 10 and represents
B ¹ , B ² and B ³ are independently hydrogen atoms and linear or branched alkyl groups having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl groups are , The oxygen atoms may be independently substituted with oxygen atoms, -CO-, -COO- or -OCO-, assuming that they do not bond directly to each other, and one or more of the alkyl groups. The hydrogen atom may be independently substituted with a halogen atom or a trialkylsilyl group having 3 to 6 carbon atoms.)).

The general formula (X1a) is preferably a compound represented by the general formula (II-b).

一般式（ＩＩ−ｂ）で表される化合物は、具体的には下記式（ＩＩ−ｑ）〜（ＩＩ−ｚ）、（ＩＩ−ａａ）〜（ＩＩ−ａｌ）で表される化合物であることが好ましい。

The compound represented by the general formula (II-b) is specifically a compound represented by the following formulas (II-q) to (II-z) and (II-aa) to (II-al). Is preferable.

The compound represented by the general formula (VI), the general formula (XaI) and the general formula (II-b) may be only one kind or two or more kinds.

Further, the polymerizable compound represented by the general formula (VI) is specifically represented by the general formula (X1c).

(In the formula, R ⁷⁰ represents a hydrogen atom or a methyl group, and R ⁷¹ represents a hydrocarbon group having a condensed ring).
Exemplified compounds are shown below, but are not limited thereto.

また、低分子液晶との溶解性を高めて結晶化を抑制するのに好ましい多官能性の反応基を有する重合性化合物としては、下記一般式（Ｖ）で表される重合性化合物が好ましい（但し、一般式（Ｘ１ｂ）で表される化合物を除く。）。

Further, as the polymerizable compound having a polyfunctional reactive group which is preferable for enhancing the solubility with the low molecular weight liquid crystal and suppressing the crystallization, the polymerizable compound represented by the following general formula (V) is preferable ( However, the compound represented by the general formula (X1b) is excluded).

(In the formula, X ¹ and X ² independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² independently represent a single bond, an alkylene group having 1 to 12 carbon atoms or −O−. (CH ₂ ) represents _s − (in the formula, s represents an integer of 1 to 11 and the oxygen atom is bonded to the aromatic ring), and U represents a linear or branched number of carbon atoms 2 to 20. It represents a valent alkylene group or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which oxygen atoms are not adjacent to each other, and the number of carbon atoms is 5. It may be substituted with an alkyl group of ~ 20 (the alkylene group in the group may be substituted with an oxygen atom to the extent that the oxygen atom is not adjacent to each other) or a cyclic substituent, and k is an integer of 1 to 5. In the formula, all 1,4-phenylene groups may have any hydrogen atom substituted with -CH ₃ , -OCH ₃ , a fluorine atom, or a cyano group.)

In the above general formula (V), X ¹ and X ² independently represent a hydrogen atom or a methyl group, but when the reaction rate is important, the hydrogen atom is preferable, and it is important to reduce the reaction residual amount. In this case, a methyl group is preferable.
In the above general formula (V), Sp ¹ and Sp ² are independently single bonds, an alkylene group having 1 to 12 carbon atoms or −O− (CH ₂ ) _s − (in the formula, s is 2 to 11). The oxygen atom is bound to the aromatic ring.), But the pretilt angle in the liquid crystal display element of the present invention is the number of carbon atoms, the content with the liquid crystal, and the alignment film used. It is affected by the type and orientation treatment conditions. Therefore, although not necessarily limited, for example, when the pretilt angle is set to about 5 degrees, the carbon chain is preferably not very long, and a single bond or an alkylene group having 1 to 5 carbon atoms is more preferable, and a single bond is used. Alternatively, an alkylene group having 1 to 3 carbon atoms is more preferable. Further, in order to keep the pretilt angle within about 2 degrees, it is preferable to use a polymerizable compound having 6 to 12 carbon atoms, and more preferably 8 to 10 carbon atoms. Further, when Sp ¹ and Sp ² represent −O− (CH ₂ ) _s −, it also affects the pretilt angle, so it is preferable to adjust the lengths of Sp ¹ and Sp ² as necessary. For the purpose of increasing the pretilt angle, s is preferably 1 to 5, more preferably 1 to 3. For the purpose of reducing the pretilt angle, s is preferably 6 to 10. Further, it is preferable that at least one of Sp ¹ and Sp ² is a single bond because molecular asymmetry is exhibited and pretilt is induced.

The compound Sp ¹ and Sp ² are identical in the general formula (V) are also preferred, it is preferable to use a compound Sp ¹ and Sp ² are identical two or more. In this case, it is more preferable to use two or more kinds having different Sp ¹ and Sp ² from each other.
In the above general formula (V), U represents a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic substituent having 5 to 30 carbon atoms, and is an alkylene group in the polyvalent alkylene group. May be substituted with an oxygen atom in a range in which the oxygen atom is not adjacent, or an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group may be substituted in the range in which the oxygen atom is not adjacent). ), May be substituted with a cyclic substituent, preferably substituted with two or more cyclic substituents.
In the above general formula (V), it is preferable that U specifically represents the formulas (Va-23) from the following formulas (Va-1). In order to increase the anchoring force, biphenyl or the like having high linearity is preferable, and it is preferable to express the formulas (Va-1) to (Va-6). Further, the structures representing the formulas (Va-6) to (Va-11) are preferable in that they have high solubility in liquid crystals, and are used in combination with the formulas (Va-1) to (Va-6). preferable.

(In the equation, both ends shall be bound to Sp ¹ or Sp ^2. Z ^p1 and Z ^p2 are independently -OCH _2- , -CH ₂ O-, -COO-, -OCO-, -CF. ₂ O-, -OCF _2- , -CH ₂ CH _2- , -CF ₂ CF _2- , -CH = CH-COO-, -CH = CH-OCO-, -COO-CH = CH-, -OCO- CH = CH-, -COO-CH ₂ CH _2- , -OCO-CH ₂ CH _2- , -CH ₂ CH _2- COO-, -CH ₂ CH _2- OCO-, -COO-CH _2- , -OCO _{-CH 2 -, - CH 2 -COO} -, - CH 2 -OCO -, - CY 1 = CY 2 -, -. C≡C- or all of the 1,4-phenylene group represents in formula single bond , Any hydrogen atom may be substituted with -CH ₃ , -OCH ₃ , fluorine atom, or cyano group, and one or more CH ₂ CH ₂ groups in the cyclohexylene group. It may be replaced by −CH = CH−, −CF ₂ O−, −OCF _2- ).
When U has a ring structure, at least one of Sp ¹ and Sp ² represents -O- (CH ₂ ) _s- (in the formula, s represents an integer of 1 to 7, and an oxygen atom is bonded to an aromatic ring. It is preferable that both of them are −O− (CH ₂ ) _s− .
In the above general formula (V), k represents an integer of 1 to 5, but it is preferably a bifunctional compound in which k is 1, or a trifunctional compound in which k is 2, and more preferably a bifunctional compound. ..

Specifically, the compound represented by the general formula (V) is preferably a compound represented by the following general formula (Vb) (however, the compound represented by the general formula (X1b) is excluded).

（式中、Ｘ^１及びＸ^２はそれぞれ独立して、水素原子又はメチル基を表し、Ｓｐ^１及びＳｐ^２はそれぞれ独立して、単結合、炭素原子数１〜１２のアルキレン基又は−Ｏ−（ＣＨ_２）_ｓ−（式中、ｓは１〜１１の整数を表し、酸素原子は芳香環に結合するものとする。）を表し、Ｚ^１は−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＦ_２−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＣＨ＝ＣＨ−ＯＣＯ−、−ＣＯＯ−ＣＨ＝ＣＨ−、−ＯＣＯ−ＣＨ＝ＣＨ−、−ＣＯＯ−ＣＨ_２ＣＨ_２−、−ＯＣＯ−ＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２−ＣＯＯ−、−ＣＨ_２ＣＨ_２−ＯＣＯ−、−ＣＯＯ−ＣＨ_２−、−ＯＣＯ−ＣＨ_２−、−ＣＨ_２−ＣＯＯ−、−ＣＨ_２−ＯＣＯ−、−ＣＹ^１＝ＣＹ^２−（Ｙ^１及びＹ^２はそれぞれ独立して水素原子又はフッ素原子を表す。）、−Ｃ≡Ｃ−又は単結合を表し、Ｃは１，４−フェニレン基、トランス−１，４−シクロヘキシレン基又は単結合を表し、式中の全ての１，４−フェニレン基は、任意の水素原子がフッ素原子により置換されていてもよい。）

(In the formula, X ¹ and X ² independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² independently represent a single bond, an alkylene group having 1 to 12 carbon atoms or −O−. (CH ₂ ) represents _s − (in the equation, s represents an integer of 1 to 11 and an oxygen atom is bound to an aromatic ring), and Z ¹ represents −OCH ₂ −, −CH ₂ O−, -COO-, -OCO-, -CF ₂ O-, -OCF _2- , -CH ₂ CH _2- , -CF ₂ CF _2- , -CH = CH-COO-, -CH = CH-OCO-,- _{COO-CH = CH -, -} OCO-CH = CH -, - COO-CH 2 CH 2 -, - OCO-CH 2 CH 2 -, - CH 2 CH 2 -COO -, - CH 2 CH 2 -OCO- , -COO-CH _2- , -OCO-CH _2- , -CH _2- COO-, -CH _2- OCO-, -CY ¹ = CY ^2- (Y ¹ and Y ² are independent hydrogen atoms or Represents a fluorine atom.), -C≡C- or a single bond, C represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group or a single bond, and all 1,4 in the formula. -The phenylene group may have any hydrogen atom substituted with a fluorine atom.)

In the above general formula (Vb), X ¹ and X ² independently represent a hydrogen atom or a methyl group, but both are diacrylate derivatives representing a hydrogen atom or dimethacrylate derivatives having a methyl group. Is preferable, and a compound in which one represents a hydrogen atom and the other represents a methyl group is also preferable. As for the polymerization rate of these compounds, the diacrylate derivative is the fastest, the dimethacrylate derivative is the slowest, and the asymmetric compound is in the middle, and a preferred embodiment can be used depending on the application.

In the above general formula (Vb), Sp ¹ and Sp ² each independently represent a single bond, an alkylene group having 1 to 12 carbon atoms, or -O- (CH ₂ ) s-, but at least one of them is -O. It is preferably − (CH ₂ ) s−, and more preferably both represent −O− (CH ₂ ) s−. In this case, s is preferably 1 to 6.
In the above general formula (Vb), Z ¹ is -OCH _2- , -CH ₂ O-, -COO-, -OCO-, -CF ₂ O-, -OCF _2- , -CH ₂ CH ₂ -,- CF ₂ CF _2- , -CH = CH-COO-, -CH = CH-OCO-, -COO-CH = CH-, -OCO-CH = CH-, -COO-CH ₂ CH _2- , -OCO- _{CH 2 CH 2 -, - CH} 2 CH 2 -COO -, - CH 2 CH 2 -OCO -, - COO-CH 2 -, - OCO-CH 2 -, - CH 2 -COO -, - CH 2 -OCO -, -CY ¹ = CY ^2- (Y ¹ and Y ² each independently represent a hydrogen atom or a fluorine atom), -C≡C- or a single bond, but -OCH _2- , -CH ₂ O-, -COO-, -OCO-, -CF ₂ O-, -OCF _2- , -CH ₂ CH _2- , -CF ₂ CF _2- or single bond is preferred, -COO-, -OCO- or single Bonding is more preferred, and single binding is particularly preferred. In the above general formula (Vb), C represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group or a single bond in which any hydrogen atom may be substituted with a fluorine atom, but 1,4 -Phenylene group or single bond is preferred. When C represents a ring structure other than a single bond, Z ¹ is preferably a linking group other than a single bond, and when C is a single bond, Z ¹ is preferably a single bond.
From the above, in the above general formula (Vb), it is preferable that C represents a single bond and the ring structure is formed by two rings, and the polymerizable compound having a ring structure is specifically described in the following general formula. Compounds represented by (V-1) to (V-6) are preferable, compounds represented by general formulas (V-1) to (V-4) are particularly preferable, and compounds represented by general formulas (V-2) are represented. The compound to be used is most preferable.

Further, in the above general formula (Vb), the compounds represented by the following general formulas (V1-1) to (V1-5) are preferable in increasing the solubility in the liquid crystal composition, and the general formula (V1-1) is preferable. ) Is particularly preferable.
Further, it is also preferably used when the above general formula (Vb) is formed by three ring structures, and the compounds represented by the general formulas (V1-6) to (V1-13) have solubility in the liquid crystal composition. It is preferable to enhance it. Further, the compounds represented by the general formulas (V-1) to (V-6) having a strong anchoring force with the liquid crystal have a weak anchoring force and good compatibility with the liquid crystal composition (V1- It is also preferable to use it in combination with the compounds represented by 1) to (V1-5).

(Wherein, q1 and q2 is independently an integer of 1 to 12, ^{R 3} represents a hydrogen atom or a methyl group.)
As the compound represented by the general formula (V), specifically, the compound represented by the following general formula (Vc) is preferable in terms of increasing the reaction rate, and the pretilt angle is thermally stable. It is preferable because it makes the compound. Further, if necessary, the number of carbon atoms of Sp ¹ , Sp ² and Sp ³ can be adjusted to obtain a desired pretilt angle. The relationship between the pretilt and the number of carbon atoms shows the same tendency as in the case of two functional groups.

（式中、Ｘ^１、Ｘ^２及びＸ^３はそれぞれ独立して、水素原子又はメチル基を表し、Ｓｐ^１、Ｓｐ^２及びＳｐ^３はそれぞれ独立して、単結合、炭素原子数１〜１２のアルキレン基又は−Ｏ−（ＣＨ_２）_ｓ−（式中、ｓは２〜７の整数を表し、酸素原子は芳香環に結合するものとする。）を表し、Ｚ^１１は、−ＯＣＨ_２−、−ＣＨ_２Ｏ−、−ＣＯＯ−、−ＯＣＯ−、−ＣＦ_２Ｏ−、−ＯＣＦ_２−、−ＣＨ_２ＣＨ_２−、−ＣＦ_２ＣＦ_２−、−ＣＨ＝ＣＨ−ＣＯＯ−、−ＣＨ＝ＣＨ−ＯＣＯ−、−ＣＯＯ−ＣＨ＝ＣＨ−、−ＯＣＯ−ＣＨ＝ＣＨ−、−ＣＯＯ−ＣＨ_２ＣＨ_２−、−ＯＣＯ−ＣＨ_２ＣＨ_２−、−ＣＨ_２ＣＨ_２−ＣＯＯ−、−ＣＨ_２ＣＨ_２−ＯＣＯ−、−ＣＯＯ−ＣＨ_２−、−ＯＣＯ−ＣＨ_２−、−ＣＨ_２−ＣＯＯ−、−ＣＨ_２−ＯＣＯ−、−ＣＹ^１＝ＣＹ^２−、−Ｃ≡Ｃ−又は単結合を表し、Ｊは１，４−フェニレン基、トランス−１，４−シクロヘキシレン基又は単結合を表し、式中の全ての１，４−フェニレン基は、任意の水素原子がフッ素原子により置換されていてもよい。）

(In the formula, X ¹ , X ² and X ³ each independently represent a hydrogen atom or a methyl group, and Sp ¹ , Sp ² and Sp ³ are independent of each other and have a single bond and 1 to 12 carbon atoms. Represents an alkylene group or −O− (CH ₂ ) _s − (in the formula, s represents an integer of 2 to 7, and an oxygen atom is bound to an aromatic ring), and Z ¹¹ represents −OCH ₂ −. _{, -CH 2 O -, - COO} -, - OCO -, - CF 2 O -, - OCF 2 -, - CH 2 CH 2 -, - CF 2 CF 2 -, - CH = CH-COO -, - CH = CH-OCO-, -COO-CH = CH-, -OCO-CH = CH-, -COO-CH ₂ CH _2- , -OCO-CH ₂ CH _2- , -CH ₂ CH _2- COO-,- CH ₂ CH _2- OCO-, -COO-CH _2- , -OCO-CH _2- , -CH _2- COO-, -CH _2- OCO-, -CY ¹ = CY ^2- , -C ≡ C- or Represents a single bond, J represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group or a single bond, and all 1,4-phenylene groups in the formula have any hydrogen atom due to a fluorine atom. It may be replaced.)

It is also preferable to use a compound having a photoalignment function as the polymerizable compound. Above all, it is preferable to use a compound showing photoisomerization.
Specific examples of the polymerizable compound having a photoalignment function include the general formula (Vb).
X ¹ and X ² independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² independently represent a single bond, an alkylene group having 1 to 8 carbon atoms, or -O- (CH ₂ ). _{It represents s} − (in the equation, s represents an integer of 1 to 7, and the oxygen atom is bound to an aromatic ring), Z ¹ represents −N = N−, and C represents 1,4-phenylene. A group, a trans-1,4-cyclohexylene group (any hydrogen atom may be substituted with a fluorine atom), or a compound representing a single bond is preferable.
Of these, compounds represented by the following general formula (Vn) are preferable.

（式中、Ｒｎ１及びＲｎ２はそれぞれ独立して、水素原子又はメチル基を表し、式中、ｐｎ及びｑｎは、それぞれ独立して１〜１２の整数を示す。）

(In the formula, Rn1 and Rn2 independently represent a hydrogen atom or a methyl group, and in the formula, pn and qn each independently represent an integer of 1 to 12.)

[Polymer initiator]
As a polymerization method of the polymerizable compound used in the present invention, radical polymerization, anionic polymerization, cationic polymerization and the like can be used, but it is preferable to polymerize by radical polymerization, and radical polymerization by photofreeze rearrangement and photopolymerization initiation Radical polymerization with agents is more preferred.

As the radical polymerization initiator, a thermal polymerization initiator and a photopolymerization initiator can be used, but a photopolymerization initiator is preferable. Specifically, the following compounds are preferable.
Diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4-( 2-Hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketon, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl- 2-Dimethylamino-1- (4-morpholinophenyl) -butanone, 4'-phenoxyacetophenone, 4'-ethoxyacetophenone and other acetophenone-based;

Benzoin systems such as benzoin, benzoin isopropyl ether, benzoin isobutyl ether, benzoin methyl ether, benzoin ethyl ether;
Acylphosphine oxide system such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide;
Benzyl, methylphenylgrioxy ester type;
Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, acrylicized benzophenone, 3,3', 4,4' -Benzophenone series such as tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2,5-dimethylbenzophenone, 3,4-dimethylbenzophenone;
Thioxanthone systems such as 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone;
Aminobenzophenone systems such as Michler ketone, 4,4'-diethylaminobenzophenone;
10-Butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphorquinone and the like are preferred. Of these, benzyl dimethyl ketal is most preferred.
It is also preferable to use a plurality of polymerization initiators in consideration of radical lifetime and reactivity.

Further, without using the above-mentioned polymerization initiator, it is also possible to carry out polymerization by containing a polymerizable liquid crystal compound having a conjugated structure that absorbs ultraviolet rays as radical polymerization by photo Fries rearrangement. For example, it is preferable to use a polymerizable liquid crystal compound having a conjugated structure represented by the general formulas (X1c-1) to (X1c-4) instead of the polymerization initiator because the voltage retention rate of the liquid crystal element is not lowered. It is also preferable to use these in combination with a polymerization initiator for the purpose of promoting polymerization.

[Polymerizable liquid crystal composition]
The polymerizable liquid crystal composition used in the present invention preferably contains the above-exemplified liquid crystal composition and the above-exemplified polymerizable compound of 1% by mass or more and less than 10% by mass, but the polymerizable compound. The lower limit of the content of is preferably 2% by mass or more, the upper limit is preferably less than 9% by mass, more preferably less than 7% by mass, more preferably less than 5% by mass, and more preferably less than 4% by mass. Further, the polymerizable liquid crystal composition used in the present invention preferably contains the above-exemplified liquid crystal composition and the above-exemplified polymerizable compound of 10% by mass or more and less than 40% by mass. The lower limit of the content of the polymerizable compound in the case is preferably 9% by mass or more, more preferably 10% by mass or more, and the upper limit is preferably less than 30% by mass, more preferably less than 25% by mass, and less than 20% by mass. More preferably, less than 15% mass is more preferable. Further, the polymerizable liquid crystal composition used in the present invention preferably contains the above-exemplified liquid crystal composition and the above-exemplified polymerizable compound of 5% by mass or more and less than 15% by mass, preferably 7% by mass. More preferably, it contains a polymerizable compound of% or more and less than 12%. The polymerizable liquid crystal composition used in the present invention contains 1% by mass or more and less than 40% by mass of a polymerizable compound, so that it is uniaxially optically anisotropy or uniaxially refractive index anisotropy or easily oriented. It is preferable that a polymer network having an axial direction is formed, and it is more preferable that the optical axis or the easy axis of orientation of the polymer network and the easy axis of orientation of the low molecular weight liquid crystal are formed so as to substantially coincide with each other.

The polymer network also includes a polymer binder in which a polymer thin film is formed by aggregating a plurality of polymer networks. The polymer binder has a refractive index anisotropy indicating uniaxial orientation, and the low molecular weight liquid crystal is dispersed in the thin film, and the uniaxial optical axis of the thin film and the optical axis of the low molecular weight liquid crystal are in substantially the same direction. The feature is that they are complete. Therefore, unlike the polymer-dispersed liquid crystal or the polymer network-type liquid crystal, which is a light-scattering liquid crystal, light scattering does not occur and a high-contrast display can be obtained in a liquid crystal element using polarized light. It is characterized by shortening the time and improving the responsiveness of the liquid crystal element. Further, in the polymerizable liquid crystal composition used in the present invention, a polymer network layer is formed on the entire liquid crystal element, and a thin film layer of a polymer is formed on the liquid crystal element substrate to induce pretilt, PSA (Polymer Sustained Alginment). ) Type liquid crystal composition is different.

It is preferable to contain at least two kinds of polymerizable compounds having different Tg at any concentration and adjust Tg as necessary. The polymerizable compound which is a precursor of the polymer having a high Tg is a polymerizable compound having a molecular structure having a high crosslink density, and preferably has 2 or more functional groups. Further, it is preferable that the precursor of the polymer having a low Tg has a structure in which the number of functional groups is 1 or 2 or more, an alkylene group or the like is provided as a spacer between the functional groups, and the molecular length is lengthened. When adjusting the Tg of the polymer network for the purpose of improving the thermal stability and impact resistance of the polymer network, it is preferable to appropriately adjust the ratio of the polyfunctional monomer to the monofunctional monomer. Tg is also associated with molecular-level thermal motility in the main and side chains of the polymer network, affecting electro-optic properties. For example, when the crosslink density is increased, the molecular motility of the main chain decreases, the anchoring force with the low-molecular-weight liquid crystal increases, the driving voltage increases, and the fall-down time becomes shorter. On the other hand, when the crosslink density is lowered so that the Tg is lowered, the thermal motility of the polymer main chain is increased, so that the anchoring force with the low molecular weight liquid crystal is lowered, the driving voltage is lowered, and the falling time tends to be long. The anchoring force at the polymer network interface is affected by the molecular motility of the polymer side chain in addition to the above-mentioned Tg, and by using a polymerizable compound having a polyvalent branched alkylene group and a polyvalent alkyl group, the polymer is used. The anchoring force at the interface is reduced. Further, the polymerizable compound having a multivalent branched alkylene group and a multivalent alkyl group is effective in inducing a pretilt angle and acts in a direction of lowering the anchoring force in the polar angle direction.

By polymerizing the polymerizable compound in the polymerizable liquid crystal composition while the polymerizable liquid crystal composition shows a liquid crystal phase, the molecular weight of the polymerizable compound is increased and the liquid crystal composition and the polymerizable compound are phase-separated. .. The form of separation into two phases differs greatly depending on the type of liquid crystal compound contained and the type of polymerizable compound. A phase-separated structure may be formed by binodal decomposition in which innumerable polymerizable compound phases are generated and grown as island-like nuclei in the liquid crystal phase, and the phase is separated from the fluctuation of the concentration between the liquid crystal phase and the polymerizable compound phase. A phase-separated structure may be formed by spinodal decomposition. In order to form a polymer network by binodal decomposition, it is preferable that the content of the low molecular weight liquid crystal is at least 85% by mass or more, and by using a compound having a high reaction rate of the polymerizable compound, the size is smaller than the wavelength of visible light. It is preferable because a nano-order phase-separated structure is formed by generating innumerable nuclei of the polymerizable compound of. As a result, as the polymerization in the polymerizable compound phase proceeds, a polymer network having void intervals shorter than the wavelength of visible light is formed depending on the phase separation structure, while the voids in the polymer network are due to the phase separation of the low molecular weight liquid crystal phase. If the size of this void is smaller than the wavelength of visible light, there is no light scattering and high contrast, and the influence of the anchoring force from the polymer network becomes stronger, the fall time becomes shorter, and the liquid crystal display element with high-speed response. Is particularly preferable.

The nucleation of the polymerizable compound phase in the binodal decomposition is affected by changes in compatibility depending on the type and combination of compounds, and parameters such as reaction rate and temperature, and is preferably adjusted as necessary. In the case of ultraviolet polymerization, the reaction rate depends on the functional group of the polymerizable compound, the type and content of the photoinitiator, and the ultraviolet exposure intensity, and the ultraviolet exposure conditions may be appropriately adjusted so as to promote the reactivity, at least. Ultraviolet exposure intensity of 20 mW / cm ² or more is preferable. When the low molecular weight liquid crystal content is 85% by mass or more, it is preferable to form a polymer network with a phase-separated structure by spinodal decomposition. In spinodal decomposition, a phase-separated microstructure due to periodic fluctuation of two-phase concentration can be obtained, so that visible light can be obtained. It is preferable because it easily forms uniform gaps smaller than the wavelength. It is preferably formed with a polymer network. When the proportion of the polymerizable compound is less than 15% by mass, it is preferable to form a phase-separated structure by spinodal decomposition, and when it is 15% by mass or more, it is preferable to form a phase-separated structure by spinodal decomposition. When the content of the polymerizable compound increases, there is a phase transition temperature at which the low molecular weight liquid crystal phase and the polymerizable compound phase are separated into two phases due to the influence of temperature. An isotropic phase is exhibited at a temperature higher than the two-phase separation transition temperature, but separation occurs at a temperature higher than the two-phase separation transition temperature, and a uniform phase separation structure cannot be obtained, which is not preferable. When two-phase separation is performed by temperature, it is preferable to form a phase-separated structure at a temperature higher than the two-phase separation temperature. In any of the above cases, the polymer network is formed while maintaining the same orientation state as that of the low molecular weight liquid crystal. The polymer network formed exhibits optical anisotropy to follow the orientation of the low molecular weight liquid crystal. The form of the liquid crystal layer in the polymer network includes a structure in which the liquid crystal composition forms a continuous layer in the three-dimensional network structure of the polymer, a structure in which the droplets of the liquid crystal composition are dispersed in the polymer, or a mixture of both. Further, there is a structure in which a polymer network layer exists starting from both substrate surfaces and only a liquid crystal layer is present near the center of the facing substrate. In any structure, it is preferable that a pretilt angle of 0 to 90 ° is induced with respect to the interface of the liquid crystal element substrate by the action of the polymer network. The polymer network to be formed preferably has a function of orienting the coexisting low-molecular-weight liquid crystal in the orientation direction indicated by the alignment film of the liquid crystal cell, and further has a function of pre-tilting the low-molecular-weight liquid crystal with respect to the polymer interface direction. It is also preferable to have. Introducing a polymerizable compound that pretilts the low molecular weight liquid crystal with respect to the polymer interface is useful and preferable for lowering the driving voltage of the liquid crystal element. Further, it may have refractive index anisotropy, and it is preferable to use a polymerizable compound having a mesogen group for the function of orienting the liquid crystal in the orientation direction.

For a vertically oriented cell such as VA mode, a polyvalent alkyl group having no mesogen group that induces vertical orientation or a polymerizable compound having a polyvalent branched alkylene group may be used, and a polymerizable compound having a mesogen group may be used. It is also preferable to use in combination with. When a polymer network is formed in a vertically oriented cell by phase separation polymerization using the above-mentioned polymerizable liquid crystal composition, the fibrous or columnar polymer network is in the direction perpendicular to the liquid crystal cell substrate. It is preferable that they are formed in substantially the same direction. Further, when a vertical alignment film on the surface of the cell substrate is subjected to a rubbing treatment or the like so as to induce tilt orientation of the liquid crystal to induce a pretilt angle, the vertical alignment film is pretilted and oriented. It is preferable that the fibrous or columnar polymer network is inclined in the same direction as the low molecular weight liquid crystal.
Further, in the method of inducing the pretilt angle while applying a voltage, when the polymerization is carried out while applying a voltage in the range of a voltage about 0.9V lower than the threshold voltage of the polymerizable liquid crystal composition to about 2V higher, the polymer is fibrous. Alternatively, it is more preferable because the columnar polymer network is formed at an angle so as to induce a desired pretilt angle, preferably 0.1 to 30 °. The fibrous or columnar polymer network formed by either method is characterized in that the two cell substrates are connected to each other. As a result, the thermal stability of the pre-tilt angle is improved, and the reliability of the liquid crystal display element can be improved.
In addition, as a method of inducing a pretilt angle of a low molecular weight liquid crystal by forming a fibrous or columnar polymer network in a slanted orientation, the number of carbon atoms of the alkylene group between the functional group and the mesogen group is 6 or more. A method of using a bifunctional acrylate having a small induction angle of the pretilt angle and a functional group and a bifunctional acrylate having a large pretilt angle of 5 or more carbon atoms of the alkylene group between the mesogen groups and having a large induction angle can be mentioned. A desired pretilt angle can be induced by adjusting the compounding ratio of these compounds.

Further, a method of adding a polymerizable compound having a reversible photoalignment function in a range of at least 0.01% or more and 1% or less to form a fibrous or columnar polymer network can be mentioned. In this case, the trans body has a rod-like shape similar to that of the low-molecular-weight liquid crystal, and affects the orientation state of the low-molecular-weight liquid crystal. When the trans body contained in the polymerizable liquid crystal composition of the present invention is exposed to ultraviolet rays as parallel light from the upper surface of the cell, the direction in which the ultraviolet rays travel and the direction of the rod-shaped molecular long axis are aligned so as to be parallel, and the molecules are low molecules. At the same time, the liquid crystal is also oriented so as to be aligned in the molecular major axis direction of the transformer body. When the cell is tilted and exposed to ultraviolet rays, the molecular major axis of the transformer body is oriented in the tilting direction and the liquid crystal is oriented in the tilting direction of the ultraviolet rays. That is, it induces a pre-tilt angle and exhibits a photo-alignment function. The pretilt angle induced by cross-linking the polymerizable compound at this stage is immobilized by the fibrous or columnar polymer network formed by the polymerization phase separation. Therefore, the induction of the pretilt angle, which is important in the VA mode, includes a method of separating the polymerization phase while applying a voltage, a method of adding a plurality of polymerizable compounds having different induced pretilt angles to separate the polymerization phase, and a reversible photoalignment function. The liquid crystal element of the present invention can be produced by using a method of aligning a low molecular weight liquid crystal and a polymerizable liquid crystal compound in the direction in which ultraviolet rays travel by using the photoalignment function exhibited by the polymerizable compound and separating the polymerization phase, if necessary. ..
The polymerizable compound having a photoalignment function is preferably a photoisomeric compound that absorbs ultraviolet rays to form a trans form, and further, the reaction rate of the polymerizable compound having a photoalignment function is a polymerizable compound having a photoalignment function. It is preferable that the reaction rate is slower than that of the polymerizable compounds other than the above. Upon UV exposure, the polymerizable compound having a photoalignment function immediately becomes a transformer, and when it is oriented in the direction in which light travels, the surrounding polymerizable liquid crystal compound is also oriented in the same direction. At this time, the polymerization phase separation progresses, and the long axis direction of the low molecular weight liquid crystal and the easy axis direction of the polymer network are aligned in the same direction as the easy alignment axis of the polymerizable compound having a photoalignment function, and the pretilt angle is in the direction in which the UV light advances. Is induced.

Furthermore, in parallel oriented cells such as IPS and FFS modes, fibrous or columnar polymer networks are present on the liquid crystal cell substrate surface in the orientation direction of the alignment film by phase-separation polymerization using a polymerizable liquid crystal composition. The low-molecular-weight liquid crystal is oriented in parallel, but the fibrous or columnar polymer network formed has anisotropy of refractive index or easy orientation. The axial direction and the orientation direction of the low-molecular-weight liquid crystal are substantially the same. Is preferable. Further, it is more preferable that the fibrous or columnar polymer network is present in substantially the entire cell except for the voids in which the low molecular weight liquid crystal is dispersed. For the purpose of inducing the pretilt angle with respect to the polymer interface direction, it is preferable to use a polyvalent alkyl group having no mesogen group, or a polymerizable compound having a polyvalent alkylene group and a polymerizable compound having a mesogen group. ..

Further, the electro-optical characteristics are affected by the surface area of the polymer network interface and the void spacing of the polymer network, but it is important that light scattering does not occur, and it is preferable that the average void spacing is smaller than the wavelength of visible light. For example, in order to increase the surface area of the interface and reduce the gap between the voids, there is a method of increasing the content of the monomer composition. As a result, the polymer network is formed so that the surface area of the interface is increased by changing the polymerized phase separation structure and making the gaps between the voids finer, and the drive voltage and the fall time are shortened. The polymerization phase separation structure is also affected by the polymerization temperature.
In the present invention, it is preferable to increase the phase separation rate and carry out polymerization so that a phase separation structure having fine voids can be obtained. The phase separation rate is greatly affected by the compatibility between the low molecular weight liquid crystal and the polymerizable compound and the polymerization rate. Since it largely depends on the molecular structure and content of the compound, it is preferable to adjust the composition appropriately before use. When the compatibility is high, it is preferable to use a polymerizable compound having a high polymerization rate, and in the case of ultraviolet polymerization, it is preferable to increase the ultraviolet intensity. It is also preferable to increase the content of the polymerizable compound in the polymerizable liquid crystal composition. When the compatibility is low, the phase separation rate is sufficiently high, which is preferable for producing the liquid crystal device of the present invention. As a method of lowering the compatibility, a method of polymerizing at a low temperature can be mentioned. When the temperature is lowered, the orientation order of the liquid crystal is increased and the compatibility between the liquid crystal and the monomer is decreased, so that the polymerization phase separation rate can be increased. As yet another method, there is also a method of polymerizing the polymerizable liquid crystal composition at a temperature indicating a supercooled state. In this case, since the temperature may be slightly lower than the melting point of the polymerizable liquid crystal composition, it is possible to accelerate the phase separation only by lowering the temperature by several degrees, which is preferable. As a result, the surface area of the polymer network interface, which is a polymer phase separation structure corresponding to the case where a monomer composition content of several tens of percent is added to the liquid crystal, that is, a structure that acts to shorten the fall-down time, is large and the void spacing is large. A fine polymer network structure is formed. Therefore, in the polymerizable liquid crystal composition of the present invention, it is preferable to appropriately adjust the polymerizable liquid crystal composition in consideration of the orientation function, the cross-linking density, the anchoring force, and the void spacing so that the falling time is shortened.

In the liquid crystal element using the polymerizable liquid crystal composition of the present invention, it is necessary to prevent light scattering in order to obtain a high-contrast display, but the target voltage-transmittance characteristic is taken into consideration in consideration of the above method. It is important to control the phase separation structure to form an appropriate polymer network layer structure so that switching characteristics can be obtained. The polymer network layer structure will be specifically described as follows.

<Polymer network layer continuous structure>
A polymer network layer is formed on the entire surface of the liquid crystal display element in the liquid crystal phase, and the liquid crystal phase is continuous. The easy axis of the polymer network and the uniaxial optical axis are in substantially the same direction as the easy axis of the low molecular weight liquid crystal. It is preferable that the polymer network is formed so as to induce the pretilt angle of the low molecular weight liquid crystal, and the average void spacing of the polymer network is smaller than the wavelength of visible light and is smaller than at least 450 nm. It is preferable because scattering does not occur. Further, in order to make the response fall time shorter than the response time of the low molecular weight liquid crystal alone due to the interaction effect (anchoring force) between the polymer network and the low molecular weight liquid crystal, it is preferably in the range of 50 nm to 450 nm. In order to reduce the influence of the fall time of the liquid crystal cell thickness and to show a fall time comparable to that of a thin cell even if the cell thickness is thick, at least the average gap interval is in the range of about 200 nm at the lower limit and 450 nm at the upper limit. It is preferable to enter. Increasing the drive voltage becomes an issue when the average gap interval is reduced, but in order to suppress the increase in the drive voltage to 25 V or less and shorten the fall response time, it is sufficient to set the drive voltage in the range of 250 nm to 450 nm. The fall response time can be improved in the range of about 5 msec to about 1 msec, which is preferable. Further, in order to suppress the increase of the drive voltage within about 5 V, it is preferable that the average gap interval is in the range of about 300 nm to 450 nm. Further, it is also possible to control the average void spacing of the polymer network so that the falling response time is 1 msec or less. The drive voltage may increase to 30 V or more, but the average gap interval may be between about 50 nm and 250 nm, and preferably about 50 nm to 200 nm for 0.5 msec or less. The average diameter of the polymer network is preferably in the range of 20 nm to 700 nm, contrary to the average void spacing. The average diameter tends to increase as the content of the polymerizable compound increases. When the reactivity is increased and the polymerization phase separation rate is increased, the density of the polymer network increases and the average diameter of the polymer network decreases. Therefore, the phase separation conditions may be adjusted as necessary. When the content of the polymerizable compound is 10% or less, the average diameter is preferably 20 nm to 160 nm, and when the average void spacing is in the range of 200 nm to 450 nm, the average diameter is in the range of 40 nm to 160 nm. preferable. When the content of the polymerizable compound is larger than 10%, the range of 50 nm to 700 nm is preferable, and the range of 50 nm to 400 nm is more preferable.

<Polymer network layer discontinuous structure>
When the polymer network layer is formed on the entire surface of the liquid crystal display element and the liquid crystal phases are continuous, the polymer network is low and the amount required for the polymer network layer to cover the entire cell is insufficient. Layers are formed discontinuously. When the polarity of the substrate surface such as the polyimide alignment film is high, the polymerizable compound tends to gather near the liquid crystal cell substrate interface, and the polymer network layer is formed so that the polymer network grows from the substrate surface and adheres to the substrate interface, and the cell substrate is formed. The polymer network layer, the liquid crystal layer, the polymer network layer, and the opposing substrate are laminated in this order from the surface. A polymer showing a laminated structure of a polymer network layer / liquid crystal layer / polymer network layer and having a thickness of at least 0.5% or more, preferably 1% or more, more preferably 5% or more of the cell thickness with respect to the cell cross-sectional direction. When the network layer is formed, the effect of shortening the fall time is exhibited by the action of the anchoring force between the polymer network and the low-molecular-weight liquid crystal, which tends to be preferable. However, since the influence of the cell thickness becomes large, if the fall time becomes longer when the cell thickness is increased, the thickness of the polymer network layer may be increased as necessary. The structure of the polymer network in the polymer network layer is such that the low-molecular-weight liquid crystal and the easy-to-orient axis and the uniaxial optical axis are aligned in substantially the same direction, and the low-molecular-weight liquid crystal is formed so as to induce a pretilt angle. Just do it. The average gap spacing is preferably in the range of 90 nm to 450 nm.

For example, when the content of the polymerizable compound is changed from 1% by mass to 6% by mass, it is preferable to use a bifunctional monomer having a mesogen group having a high anchoring force, and the structure has a short distance between the functional groups and the polymerization rate is high. It is preferable to use a fast bifunctional monomer, and it is preferable to form a polymerized phase separated structure at a low temperature of 0 ° C. or lower. When the content of the polymerizable compound is 6% by mass to less than 10% by mass, a combination of the bifunctional monomer and a monofunctional monomer having a low anchoring force is preferable, and the range is 25 ° C. to -20 ° C. as necessary. It is preferable to form a polymerized phase separated structure with. Further, when the melting point is room temperature or higher, lowering the melting point by about 5 ° C. is preferable because the same effect as low temperature polymerization can be obtained. When the content of the polymerizable compound is changed from 10% by mass to 40% by mass, the influence of the polymer binder or the polymer network greatly affects the orientation and driving voltage of the low molecular weight liquid crystal and increases the driving voltage. It is preferable to use a polymerizable compound having a mesogen group having a relatively weak anchoring force. For example, in a polymerizable compound having a weak anchoring force and having a mesogen group, it is effective to increase the carbon number of the alkylene group between the functional group and the mesogen group, and the carbon number is preferably 5 to 10. Further, if the amount of the polymerizable compound exceeds 30% by mass, liquid crystal droplets may be dispersed in the polymer binder, and even in this case, the polymer binder has refractive index anisotropy and the orientation of the substrate surface. It is preferable that the orientation direction indicated by the film and the optical axis direction of the polymer binder are aligned.

The higher the concentration of the polymerizable compound in the polymerizable liquid crystal composition, the greater the anchoring force between the liquid crystal composition and the polymer interface, and the higher the speed of τd. On the other hand, as the anchoring force between the liquid crystal composition and the polymer interface increases, τr slows down. In order to make the sum of τd and τr less than 1.5 ms, the concentration of the polymerizable compound in the polymerizable liquid crystal composition is 1% by mass or more and less than 40% by mass, and 2% by mass or more and 15% by mass or less. Preferably, it is 3% by mass or more and 8% by mass or less.
When used in a TFT-driven liquid crystal display element, it is necessary to suppress flicker and improve reliability such as afterimages due to printing, and the voltage retention rate becomes an important characteristic. It is considered that the cause of lowering the voltage retention rate is the ionic impurities contained in the polymerizable liquid crystal composition. In particular, movable ions strongly affect the voltage retention rate. Therefore, it is preferable to remove movable ions by performing a purification treatment or the like so that at least a specific resistance of 10 ¹⁴ Ω · cm or more can be obtained. Further, when a polymer network is formed by radical polymerization, the voltage retention rate may decrease due to ionic impurities generated from a photopolymerization initiator or the like, but a polymerization initiator with a small amount of organic acid or low molecular weight by-products generated. It is preferable to select.

[Liquid crystal display element]
The liquid crystal display element of the present invention contains a polymer or a copolymer in the liquid crystal composition, and the content of the polymer or the copolymer is 1 mass of the total mass of the liquid crystal composition and the polymer or the copolymer. It has the same structure as the liquid crystal display element according to the prior art, except that it is% or more and less than 40% by mass. That is, the liquid crystal display element according to the present invention has a structure in which a liquid crystal layer is sandwiched between two transparent substrates having electrodes on at least one of them. The liquid crystal display element of the present invention preferably has an alignment layer for orienting the liquid crystal composition on at least one transparent substrate. A voltage is applied to the alignment layer provided on the substrate and the electrodes provided on the substrate to control the orientation of the liquid crystal molecules. The polymer network or polymer binder has uniaxial refractive index anisotropy or easy orientation axial direction, and the optical axis direction or easy orientation axis direction of the polymer network or polymer binder and the easy orientation axial direction of the low molecular weight liquid crystal are in the same direction. It is preferable to have. In this respect, it is different from the light scattering type polymer network liquid crystal and the polymer dispersion type liquid crystal having no uniaxial refractive index anisotropy or easy orientation axial direction. Further, it is preferable that the easy axial direction of the alignment layer and the easy axial direction of the polymer network or the polymer binder are the same. By providing a polarizing plate, a retardation film, etc., this orientation state is used for display. The liquid crystal display element can be applied to operation modes such as TN, STN, ECB, VA, VA-TN, IPS, FFS, π cell, OCB, and cholesteric liquid crystal. Of these, VA, IPS, FFS, VA-TN, TN, and ECB are particularly preferable. The liquid crystal display element of the present invention is a PSA (Polymer Sustained Alignment) type liquid crystal display element having a polymer or copolymer on an alignment film in that a polymer or copolymer is contained in the liquid crystal composition. Is different.

The distance (d) between the substrates of the liquid crystal display element of the present invention is preferably in the range of 2 to 5 μm, more preferably 3.5 μm or less. Generally, the birefringence is adjusted so that the product of the birefringence of the liquid crystal composition and the cell thickness is close to 0.275, but in the polymerizable liquid crystal composition of the present invention, a polymer network is formed after the polymerization phase is separated. Therefore, the birefringence of the liquid crystal display element when an electric field is applied is lowered due to the anchoring force action of the polymer network and the optical properties of the polymer network, so that the birefringence is contained in the liquid crystal composition, the polymer composition, or the polymerizable liquid crystal composition. The product of the birefringence (Δn) of the liquid crystal composition and the distance (d) between the substrates is particularly preferably in the range of 0.3 to 0.4 μm when the driving voltage is increased within about 5 V due to the formation of the polymer network. The range of 0.30 to 0.35 μm is more preferable for the increase within a degree, and the range of 0.29 to 0.33 μm is particularly preferable for the increase of the drive voltage within 1 V. By setting the product of the distance (d) between the substrates of the liquid crystal display element and the birefringence (Δn) of the liquid crystal composition and the distance (d) between the substrates within the above ranges, the transmittance is limited to the low molecular weight liquid crystal only. It is possible to obtain a display that is comparablely high, has a high-speed response, and has favorable color reproducibility. The birefringence of the liquid crystal composition used in the polymerizable liquid crystal composition can be set to 1 to 1.9 times the product of the cell thickness (d) and the birefringence (Δn) with respect to 0.275. preferable.

The driving voltage of the liquid crystal display element of the present invention is not only determined by the dielectric anisotropy and elastic constant of the liquid crystal composition, but is greatly influenced by the anchoring force acting between the liquid crystal composition and the polymer interface.
For example, as a description regarding the driving voltage of the polymer-dispersed liquid crystal display element, the relationship of the following equation is shown in JP-A-6-222320.

(Vth represents the threshold voltage, 1Kii and 2Kii represent the elastic constants, i represents 1, 2 or 3, Δε represents the dielectric anisotropy, and <r> represents the transparent polymer material interface. The average void spacing is represented, A represents the anchoring force of the transparent polymer substance with respect to the liquid crystal composition, and d represents the distance between the substrates having the transparent electrodes.)

According to this, the driving voltage of the light scattering type liquid crystal display element is the average void spacing of the transparent polymer substance interface, the distance between the substrates, the elastic constant / dielectric anisotropy of the liquid crystal composition, and the liquid crystal composition and the transparent. Determined by the anchoring energy between the sex polymer materials.
Of these, the parameters that can be controlled by the liquid crystal display element of the present invention are the physical properties of the liquid crystal and the anchoring force between the polymers. Since the anchoring force largely depends on the molecular structure of the polymer and the molecular structure of the low-molecular-weight liquid crystal, the response time can be shortened to 1.5 ms or less by selecting a polymerizable compound having a strong anchoring force. At the same time, since the drive voltage increases to 30 V or more, it is preferable to appropriately select a liquid crystal compound and a polymerizable compound so that the drive voltage is 30 V or less and the response speed is 1.5 ms or less to adjust the composition. .. It is preferable to appropriately blend a polymer precursor having a strong anchoring force and a polymer precursor having a weak anchoring force to adjust the composition so that the drive voltage and the response speed are balanced. On the other hand, as the physical properties of the liquid crystal composition required for lowering the drive voltage, it is particularly preferable that the P-type liquid crystal has a dielectric anisotropy of 6 or more and the N-type liquid crystal has a dielectric anisotropy of -3 or less. .. Moreover, it is preferable that the birefringence is 0.09 or more. Further, it is more preferable that the birefringence of the liquid crystal composition and the refractive index of the fibrous or columnar polymer network are as close as possible to eliminate light scattering. However, since the retardation of the liquid crystal element is affected by the concentration of the polymer precursor, it is preferable to increase or decrease the birefringence of the liquid crystal composition so that the required retardation can be obtained as appropriate.

The liquid crystal display element of the present invention irradiates the above-mentioned liquid crystal composition with energy rays at −50 ° C. to 30 ° C. to polymerize a polymerizable compound, and the refractive index anisotropy or easy orientation axis in the liquid crystal composition. It is preferably obtained by forming a polymer network having a direction. The upper limit of the polymerization temperature is 30 ° C, preferably 20 ° C to −10 ° C. As will be described later in Examples, the present inventor has found that τd is further accelerated by low-temperature polymerization and normal-temperature polymerization depending on the composition of the polymerizable compound. The reason for this is that 1) the polymerization is carried out in a state where the degree of orientation of the liquid crystal molecules is increased due to the low temperature, and 2) the compatibility between the polymer polymerized by the low temperature polymerization and the liquid crystal composition is lowered, so that phase separation becomes easy and the polymerization is carried out. The phase separation rate is increased and the void spacing of the polymer network becomes fine. 3) Even if a polymerizable compound having a relatively low anchoring force is used, the void spacing is fine, so that the influence of the anchoring force becomes stronger. It is considered that this is due to the formation of a uniform refractive index anisotropic polymer network.

Further, in the liquid crystal display element of the present invention, the optical axis direction or the easy orientation axial direction of the polymer network or polymer binder having uniaxial refractive anisotropy or easy orientation axial direction forms a pretilt angle with respect to the transparent substrate. The energy rays are generated while applying a voltage to the liquid crystal layer described above by adjusting the strength of the electric field to control the orientation of the low-molecular-weight liquid crystal and inclining it with respect to the substrate surface. It is preferable that the polymer is polymerized by irradiation to obtain a polymer having anisotropy of refractive index or easy axial direction in the liquid crystal composition. In the vertically oriented VA mode, a voltage is applied to polymerize the pretilt angle so that the pretilt angle is within 20 degrees with respect to the normal direction of the substrate, thereby polymerizing. It is particularly preferable because it not only has an effect corresponding to fine polymer protrusions of PSA liquid crystal, but also exhibits a high-speed response that cannot be realized by PSA. Further, by applying the electric field direction from a plurality of directions to polymerize the polymer, a multi-domain can be formed, and the viewing angle can be improved, which is more preferable. Further, by performing photo-alignment treatment, rubbing alignment treatment, etc. on the alignment film so that the low-molecular-weight liquid crystal induces a pre-tilt angle at the substrate interface vertical alignment film interface, the inclination direction of the low-molecular-weight liquid crystal alignment is defined and during switching. It is preferable that the occurrence of orientation defects is suppressed, and it is also preferable to perform the orientation treatment so as to tilt in a plurality of directions. The liquid crystal layer has refractive index anisotropy by appropriately applying an AC electric field in the temperature range of -50 ° C to 30 ° C and irradiating the liquid crystal composition containing the polymerizable compound with ultraviolet rays or electron beams. Is formed in the liquid crystal so that the optical axis direction of the polymer network having the above forms a pretilt angle with respect to the substrate surface. This pretilt angle is a liquid crystal element in which the optical axis of the polymer network after polymerization is tilted with respect to the substrate surface when the polymerization phase is separated in the orientation state induced by applying an electric field due to the dielectric anisotropy of the low molecular weight liquid crystal. It is more preferable that the polymerizable compound is polymerized.

For the two substrates used in the liquid crystal display element of the present invention, a transparent material having flexibility such as glass or plastic can be used. A transparent substrate having a transparent electrode layer can be obtained, for example, by sputtering indium tin oxide (ITO) on a transparent substrate such as a glass plate.

The color filter can be produced by, for example, a pigment dispersion method, a printing method, an electrodeposition method, a dyeing method, or the like. To explain a method for producing a color filter by a pigment dispersion method as an example, a curable coloring composition for a color filter is applied onto the transparent substrate, subjected to a patterning treatment, and cured by heating or light irradiation. By performing this step for each of the three colors of red, green, and blue, a pixel portion for a color filter can be created. In addition, a pixel electrode provided with an active element such as a TFT or a thin film diode may be installed on the substrate.

The substrates are opposed to each other so that the transparent electrode layer is on the inside. At that time, the spacing between the substrates may be adjusted via a spacer. At this time, it is preferable to adjust the thickness of the obtained dimming layer to be 1 to 100 μm. 1.5 to 10 μm is more preferable, and when a polarizing plate is used, the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d is adjusted so as to maximize the contrast, and 1 / of 550 nm depending on the display mode. It is preferable to set it to 2 or 1/4. Further, when there are two polarizing plates, the polarization axis of each polarizing plate can be adjusted so that the viewing angle and contrast can be improved. Further, a retardation film for widening the viewing angle can also be used. Examples of the spacer include a columnar spacer made of glass particles, plastic particles, alumina particles, a photoresist material, and the like. Then, a sealant such as an epoxy-based thermosetting composition is screen-printed on the substrate in the form of providing a liquid crystal injection port, the substrates are bonded to each other, and the sealant is thermoset by heating.

As a method for sandwiching the polymerizable liquid crystal composition between the two substrates, a normal vacuum injection method, an ODF method, or the like can be used. In the ODF method liquid crystal display element manufacturing process, a sealant such as epoxy-based photothermal curable is drawn on either the backplane or frontplane substrate in the form of a closed-loop bank using a dispenser, and the sealant is removed from the substrate. A liquid crystal display element can be manufactured by dropping a predetermined amount of the polymerizable liquid crystal composition under the air and then joining the front plane and the back plane. The polymerizable liquid crystal composition used in the present invention can be preferably used because the liquid crystal / monomer composite material can be stably dropped in the ODF step.

As a method for polymerizing a polymerizable compound, an appropriate polymerization rate is desirable in order to obtain good orientation performance of the liquid crystal. Therefore, irradiation with ultraviolet rays or electron beams, which are active energy rays, in single or in combination or in sequence. The method of polymerizing by is preferable. When ultraviolet rays are used, a polarized light source may be used, or a non-polarized light source may be used. Further, when the polymerizable liquid crystal composition is sandwiched between two substrates for polymerization, at least the substrate on the irradiation surface side must be provided with appropriate transparency for active energy rays. .. Further, for a liquid crystal composition containing a polymerizable compound,
It is preferable to apply an AC electric field to the polymerizable liquid crystal composition in a temperature range of −50 ° C. to 20 ° C. and to irradiate the polymerizable liquid crystal composition with ultraviolet rays or electron beams. The AC electric field to be applied is preferably an AC having a frequency of 10 Hz to 10 kHz, more preferably a frequency of 100 Hz to 5 kHz, and the voltage is selected depending on a desired pretilt angle of the liquid crystal display element. That is, the pretilt angle of the liquid crystal display element can be controlled by the applied voltage. In the horizontal electric field type MVA mode liquid crystal display element, it is preferable to control the pretilt angle from 80 degrees to 89.9 degrees from the viewpoint of orientation stability and contrast.

The temperature at the time of irradiation is preferably in the temperature range of −50 ° C. to 30 ° C. for the polymerizable liquid crystal composition. As the lamp that generates ultraviolet rays, a metal halide lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or the like can be used. Further, as the wavelength of the ultraviolet rays to be irradiated, it is preferable to irradiate the ultraviolet rays in a wavelength region other than the absorption wavelength region of the liquid crystal composition, and it is preferable to cut off the ultraviolet rays of less than 365 nm before use. Intensity of ultraviolet irradiation is ^preferably from ^{0.1mW / cm 2 ~100W / cm 2} , 2mW / cm 2 ~50W / cm 2 is more preferable. The amount of energy of the ultraviolet rays to be irradiated can be appropriately adjusted, but is preferably 10 mJ / cm ² to 500 J / cm ^{2, and} more preferably 100 mJ / cm ² to 200 J / cm ² . The intensity may be changed when irradiating with ultraviolet rays. The time for irradiating the ultraviolet rays is appropriately selected depending on the intensity of the ultraviolet rays to be irradiated, but is preferably 10 seconds to 3600 seconds, more preferably 10 seconds to 600 seconds.

(Horizontal electric field type)
First, the liquid crystal display element according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the liquid crystal display element of the present invention. The liquid crystal display element 10 of the embodiment of the present invention is provided so as to be separated from the first substrate 2 on which the alignment layer 4 is formed on the surface and the first substrate, and the photoalignment layer is formed on the surface. The second substrate 7 and the liquid crystal layer 5 filled between the first substrate 2 and the second substrate 7 and in contact with the pair of alignment layers are provided, and the alignment layers 4 (4a, 4b) are provided. ) And the first substrate 2 have an electrode layer 3 provided with a thin film transistor, a common electrode 22, and a pixel electrode as active elements.

FIG. 1 is a diagram schematically showing a configuration of a liquid crystal display element. In FIG. 1, each component is described separately for convenience of explanation. As shown in FIG. 1, the configuration of the liquid crystal display element 10 according to the embodiment of the present invention is sandwiched between the first transparent insulating substrate 2 arranged to face each other and the second transparent insulating substrate 7. It is a liquid crystal display element of a transverse electric field system (FFS mode as one form of IPS as an example in the figure) having a polymerizable liquid crystal composition (or liquid crystal layer 5). In the first transparent insulating substrate 2, the electrode layer 3 is formed on the surface on the liquid crystal layer 5 side. Further, a pair of the liquid crystal layer 5 and each of the first transparent insulating substrate 2 and the second transparent insulating substrate 7 are in direct contact with the polymerizable liquid crystal composition constituting the liquid crystal layer 5 to induce homogenic orientation. The liquid crystal molecules in the polymerizable liquid crystal composition have the alignment films 4 (4a, 4b) of the above, and are oriented so as to be substantially parallel to the substrates 2 and 7 when no voltage is applied. As shown in FIGS. 1 and 3, the second substrate 7 and the first substrate 2 may be sandwiched by a pair of polarizing plates 1 and 8. Further, in FIG. 1, a color filter 6 is provided between the second substrate 7 and the alignment film 4. The liquid crystal display element according to the present invention may be a so-called color filter-on-array (COA), a color filter may be provided between the electrode layer including the thin film transistor and the liquid crystal layer, or the thin film transistor may be provided. A color filter may be provided between the electrode layer containing the above and the second substrate.
That is, the liquid crystal display element 10 of the embodiment of the present invention includes the first polarizing plate 1, the first substrate 2, the electrode layer 3 including the thin film transistor, the alignment film 4, and the polymerizable liquid crystal composition. The liquid crystal layer 5, the alignment film 4, the color filter 6, the second substrate 7, and the second polarizing plate 8 are sequentially laminated.
For the first substrate 2 and the second substrate 7, a transparent material having flexibility such as glass or plastic can be used, and one of them may be an opaque material such as silicon. The two substrates 2 and 7 are bonded by a sealing material and a sealing material such as an epoxy-based thermosetting composition arranged in a peripheral region, and in order to maintain a distance between the substrates, for example, Granular spacers such as glass particles, plastic particles, and alumina particles, or spacer columns made of resin formed by a photolithography method may be arranged.

FIG. 2 is an enlarged plan view of the region of the electrode layer 3 formed on the substrate 2 in FIG. 1 surrounded by the line II. FIG. 3 is a cross-sectional view of the liquid crystal display element shown in FIG. 1 cut in the direction of line III-III in FIG. As shown in FIG. 2, the electrode layer 3 including the thin film transistor formed on the surface of the first substrate 2 has a plurality of gate wirings 24 for supplying scanning signals and a plurality of data for supplying display signals. The wiring 25 and the wiring 25 are arranged so as to intersect each other in a matrix. Note that FIG. 2 shows only a pair of gate wirings 24 and a pair of data wirings 25.
A unit pixel of a liquid crystal display device is formed by a region surrounded by a plurality of gate wirings 24 and a plurality of data wirings 25, and a pixel electrode 21 and a common electrode 22 are formed in the unit pixel. A thin film transistor including a source electrode 27, a drain electrode 26, and a gate electrode 28 is provided in the vicinity of the intersection where the gate wiring 24 and the data wiring 25 intersect with each other. This thin film transistor is connected to the pixel electrode 21 as a switch element that supplies a display signal to the pixel electrode 21. Further, a common line (not shown) is provided in parallel with the gate wiring 24. This common line is connected to the common electrode 22 in order to supply a common signal to the common electrode 22.

A preferred embodiment of the structure of the thin film is provided so as to cover the gate electrode 11 formed on the surface of the substrate 2 and the gate electrode 11 and substantially the entire surface of the substrate 2, for example, as shown in FIG. The gate insulating layer 12 formed, the semiconductor layer 13 formed on the surface of the gate insulating layer 12 so as to face the gate electrode 11, and the protective layer provided so as to cover a part of the surface of the semiconductor layer 13. A drain electrode 16 provided to cover one side end of the protective layer 14 and the semiconductor layer 13 and to be in contact with the gate insulating layer 12 formed on the surface of the substrate 2, and the protection. A source electrode 17 provided so as to cover the other side end of the layer 14 and the semiconductor layer 13 and in contact with the gate insulating layer 12 formed on the surface of the substrate 2, the drain electrode 16 and the source. It has an insulating protective layer 18 provided so as to cover the electrode 17. An anodized film (not shown) may be formed on the surface of the gate electrode 11 for reasons such as eliminating a step with the gate electrode.

Amorphous silicon, polycrystalline polysilicon, and the like can be used for the semiconductor layer 13, but if a transparent semiconductor film such as ZnO, IGZO (In-Ga-Zn-O), or ITO is used, it is caused by light absorption. It is also preferable from the viewpoint of suppressing the harmful effects of optical carriers and increasing the opening ratio of the device.
Further, an ohmic contact layer 15 may be provided between the semiconductor layer 13 and the drain electrode 16 or the source electrode 17 for the purpose of reducing the width and height of the Schottky barrier. For the ohmic contact layer, a material to which impurities such as phosphorus such as n-type amorphous silicon and n-type polycrystalline polysilicon are added at a high concentration can be used.

The gate wiring 26, the data wiring 25, and the common line 29 are preferably a metal film, more preferably Al, Cu, Au, Ag, Cr, Ta, Ti, Mo, W, Ni or an alloy thereof, and Al or an alloy thereof. It is particularly preferable to use the wiring of. The insulating protective layer 18 is a layer having an insulating function, and is formed of silicon nitride, silicon dioxide, a silicon oxynitride film, or the like.

In the embodiment shown in FIGS. 2 and 3, the common electrode 22 is a flat plate-shaped electrode formed on substantially the entire surface of the gate insulating layer 12, while the pixel electrode 21 is an insulating protective layer 18 covering the common electrode 22. It is a comb-shaped electrode formed on the top. That is, the common electrode 22 is arranged at a position closer to the first substrate 2 than the pixel electrode 21, and these electrodes are arranged so as to overlap each other via the insulating protective layer 18. The pixel electrode 21 and the common electrode 22 are formed of, for example, a transparent conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and IZTO (Indium Zinc Tin Oxide). Since the pixel electrode 21 and the common electrode 22 are formed of a transparent conductive material, the area opened in a unit pixel area becomes large, and the opening ratio and the transmittance increase.

Further, in order to form a fringe electric field between the pixel electrode 21 and the common electrode 22, the distance between the electrodes 21 and the common electrode 22 (also referred to as the minimum separation distance): R is determined. Distance between the first substrate 2 and the second substrate 7: Formed so as to be smaller than G. Here, the distance between the electrodes: R represents the distance in the horizontal direction on the substrate between the electrodes. In FIG. 3, since the flat plate-shaped common electrode 22 and the comb-shaped pixel electrode 21 overlap each other, an example is shown in which the distance between the electrodes: R = 0, and the minimum separation distance: R is the first substrate 2. Distance between and the second substrate 7 (that is, cell gap): Since it is smaller than G, a fringe electric field E is formed. Therefore, the FFS type liquid crystal display element can utilize a horizontal electric field formed in a direction perpendicular to the comb-shaped line of the pixel electrode 21 and a parabolic electric field. The electrode width of the comb-shaped portion of the pixel electrode 21: l and the width of the gap of the comb-shaped portion of the pixel electrode 21: m are such that all the liquid crystal molecules in the liquid crystal layer 5 can be driven by the generated electric field. It is preferable to form. Further, the minimum separation distance R between the pixel electrode and the common electrode can be adjusted as the (average) film thickness of the gate insulating layer 12. Further, in the liquid crystal display element according to the present invention, unlike FIG. 3, the distance between the electrodes (also referred to as the minimum separation distance) between the pixel electrode 21 and the common electrode 22: R is the first substrate 2 and the second. Distance from the substrate 7: It may be formed so as to be larger than G (IPS method). In this case, for example, a configuration in which comb-shaped pixel electrodes and comb-shaped common electrodes are provided alternately in substantially the same plane can be mentioned.

A preferred form of the liquid crystal display element according to the present invention is preferably an FFS type liquid crystal display element that utilizes a fringe electric field, and the shortest distance d adjacent to the common electrode 22 and the pixel electrode 21 is the alignment film 4. If it is shorter than the shortest separation distance D between the two (distance between substrates), a fringe electric field is formed between the common electrode and the pixel electrode, and the horizontal and vertical orientations of the liquid crystal molecules can be efficiently used. In the case of the FFS type liquid crystal display element of the present invention, when a voltage is applied to the liquid crystal molecules arranged so that the major axis direction is parallel to the orientation direction of the alignment layer, the voltage is applied between the pixel electrode 21 and the common electrode 22. Isopotential lines of a parabolic electric field are formed up to the upper part of the pixel electrode 21 and the common electrode 22, and are arranged along the electric field on which the long axis of the liquid crystal molecules in the liquid crystal layer 5 is formed. Therefore, the liquid crystal molecules can be driven even with low dielectric anisotropy.

The color filter 6 according to the present invention preferably has a black matrix (not shown) formed in a portion corresponding to the thin film transistor and the storage capacitor 23 from the viewpoint of preventing light leakage. Further, the color filter 6 is usually composed of three filter pixels of R (red) G (green) B (blue) and one dot of an image or an image. For example, these three filters are arranged in the extending direction of the gate wiring. There is. The color filter 6 can be produced by, for example, a pigment dispersion method, a printing method, an electrodeposition method, a dyeing method, or the like. Explaining a method for producing a color filter by a pigment dispersion method as an example, a curable coloring composition for a color filter is applied onto the transparent substrate, subjected to a patterning treatment, and cured by heating or light irradiation. By performing this step for each of the three colors of red, green, and blue, a pixel portion for a color filter can be produced. In addition, a so-called color filter-on array in which pixel electrodes provided with active elements such as TFTs and thin film diodes are provided on the substrate may be used.
On the electrode layer 3 and the color filter 6, a pair of alignment films 4 that directly contact with the polymerizable liquid crystal composition constituting the liquid crystal layer 5 to induce homogenous orientation are provided.
Further, the polarizing plate 1 and the polarizing plate 8 can be adjusted so that the viewing angle and the contrast are good by adjusting the polarization axes of the polarizing plates so that the transmission axes thereof operate in the normal black mode. It is preferable to have transmission axes that are orthogonal to each other. In particular, it is preferable that either the polarizing plate 1 or the polarizing plate 8 is arranged so as to have a transmission axis parallel to the orientation direction of the liquid crystal molecules. Further, it is preferable to adjust the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d so that the contrast is maximized. Further, a retardation film for widening the viewing angle can also be used.
Further, as another embodiment of the liquid crystal display element, in the case of the IPS system, the shortest separation distance d between the adjacent common electrode and the pixel electrode is longer than the shortest separation distance G between the liquid crystal alignment films. When the electrodes and the pixel electrodes are formed on the same substrate and the common electrodes and the pixel electrodes are alternately arranged, the shortest separation distance d between the adjacent common electrodes and the pixel electrodes is the liquid crystal orientation. Examples thereof include a structure longer than the shortest separation distance G between the films.

In the method for manufacturing a liquid crystal display element according to the present invention, after forming a coating on a substrate having an electrode layer and / or the surface of the substrate, the pair of substrates are separated from each other so that the coating is on the inside, and then the liquid crystal is displayed. It is preferable to fill the composition between the substrates. At that time, it is preferable to adjust the distance between the substrates via a spacer.
The distance between the substrates (which is the average thickness of the obtained liquid crystal layer and is also referred to as the separation distance between the coating films) is preferably adjusted to 1 to 100 μm. The average separation distance between the coatings is more preferably 1.5 to 10 μm.
In the present invention, examples of the spacer used for adjusting the distance between the substrates include a columnar spacer made of glass particles, plastic particles, alumina particles, a photoresist material, and the like.
The FFS type liquid crystal display element described with reference to FIGS. 1 to 3 is an example, and can be implemented in various other forms as long as it does not deviate from the technical idea of the present invention.

Other embodiments of the liquid crystal display element according to the present invention will be described below with reference to FIGS. 4 and 5. For example, FIG. 4 is another embodiment of the plan view in which the region surrounded by the line II of the electrode layer 3 formed on the substrate 2 in FIG. 1 is enlarged. As shown in FIG. 4, the pixel electrode 21 may have a slit. Further, the slit pattern may be formed so as to have an inclination angle with respect to the gate wiring 24 or the data wiring 25.
The pixel electrode 21 shown in FIG. 4 has a shape in which an electrode of a substantially rectangular flat plate body is hollowed out by a notch portion having a substantially rectangular frame shape. Further, on the back surface of the pixel electrode 21, a comb-shaped common electrode 22 is formed on one surface via an insulating protective layer 18 (not shown). When the shortest separation distance R between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the oriented layers, the FFS method is used, and when it is long, the IPS method is used. Further, it is preferable that the surface of the pixel electrode is covered with a protective insulating film and an alignment film layer. Similar to the above, the storage capacitor 23 for storing the display signal supplied via the data wiring 25 may be provided in the area surrounded by the plurality of gate wirings 24 and the plurality of data wirings 25. The shape of the notch is not particularly limited, and not only the substantially rectangular shape shown in FIG. 4, but also a notch having a known shape such as an ellipse, a circle, a rectangle, a rhombus, a triangle, or a parallelogram can be used. Can be used. Further, when the shortest separation distance R between the adjacent common electrode and the pixel electrode is longer than the shortest separation distance G between the oriented layers, the display element of the IPS system is used.

FIG. 5 is an embodiment different from that of FIG. 3, and is another example of a cross-sectional view in which the liquid crystal display element shown in FIG. 1 is cut in the direction of lines III-III in FIG. The first substrate 2 on which the electrode layer 3 including the alignment layer 4 and the thin film transistor 20 is formed on the surface and the second substrate 8 on which the alignment layer 4 is formed on the surface face each other at a predetermined interval D. The spaces are separated, and the liquid crystal layer 5 containing the liquid crystal composition is filled in this space. The gate insulating layer 12, the common electrode 22, the insulating protective layer 18, the pixel electrode 21, and the alignment layer 4 are laminated in this order on a part of the surface of the first substrate 2. Further, as shown in FIG. 4, the pixel electrode 21 has a shape in which the central portion and both ends of the flat plate body are hollowed out by a triangular notch, and the remaining region is hollowed out by a rectangular notch. The common electrode 22 has a structure in which a comb-shaped common electrode is arranged on the first substrate side of the pixel electrode 21 substantially in parallel with the substantially elliptical notch portion of the pixel electrode 21.
In the example shown in FIG. 5, a common electrode 22 having a comb shape or a slit is used, and the distance between the pixel electrodes 21 and the common electrode 22 is R = α (note that in FIG. 5, the distance between the electrodes is horizontal for convenience). Ingredients are listed as R). Further, in FIG. 3, an example in which the common electrode 22 is formed on the gate insulating layer 12 is shown, but as shown in FIG. 5, the common electrode 22 is formed on the first substrate 2. The pixel electrode 21 may be provided via the gate insulating layer 12. The electrode width of the pixel electrode 21: l, the electrode width of the common electrode 22: n, and the distance between the electrodes: R are appropriately adjusted to a width such that all the liquid crystal molecules in the liquid crystal layer 5 can be driven by the generated electric field. Is preferable. When the shortest separation distance R between the adjacent common electrode and the pixel electrode is shorter than the shortest separation distance G between the oriented layers, the FFS method is used, and when it is long, the IPS method is used. Further, although the positions of the pixel electrode 21 and the common electrode 22 in the thickness direction are different in FIG. 5, the positions of both electrodes in the thickness direction may be the same, or the common electrode may be provided on the liquid crystal layer 5 side.

(Vertical electric field type)
Another preferred embodiment of the present invention is a vertical electric field type liquid crystal display device using a liquid crystal composition. FIG. 6 is a diagram schematically showing the configuration of a vertical electric field type liquid crystal display element. Further, in FIG. 7, for convenience of explanation, each component is described separately. FIG. 7 is an enlarged plan view of the region surrounded by the VII line of the electrode layer 300 (also referred to as the thin film transistor layer 300) including the thin film transistor formed on the substrate in FIG. FIG. 8 is a cross-sectional view of the liquid crystal display element shown in FIG. 6 cut in the direction of line VIII-VIII in FIG. Hereinafter, the vertical electric field type liquid crystal display element according to the present invention will be described with reference to FIGS. 6 to 9.
The configuration of the liquid crystal display element 1000 according to the present invention includes a second substrate 800 provided with a transparent electrode (layer) 600 (also referred to as a common electrode 600) made of a transparent conductive material as shown in FIG. A first substrate 200 including a pixel electrode made of a transparent conductive material and a thin film transistor layer 300 formed by forming a thin film transistor provided on each pixel to control the pixel electrode, and the first substrate 200 and the second substrate 800. It has a polymerizable liquid crystal composition (or liquid crystal layer 500) sandwiched between them, and the orientation of the liquid crystal molecules in the polymerizable liquid crystal composition when no voltage is applied is substantially perpendicular to the substrates 200 and 800. It is a liquid crystal display element. Further, as shown in FIGS. 6 and 8, the second substrate 800 and the first substrate 200 may be sandwiched by a pair of polarizing plates 100 and 900. Further, in FIG. 6, a color filter 700 is provided between the first substrate 200 and the common electrode 600. Furthermore, a pair of alignment films 400 are formed on the surfaces of the transparent electrodes (layers) 600 and 1400 so as to be adjacent to the liquid crystal layer 500 according to the present invention and to be in direct contact with the polymerizable liquid crystal composition constituting the liquid crystal layer 500. There is.
That is, the liquid crystal display element 1000 according to the present invention includes a first polarizing plate 100, a first substrate 200, an electrode layer (also referred to as a thin film transistor layer) 300 including a thin film transistor, a photoalignment film 400, and a liquid crystal composition. The layer 500 containing the material, the alignment film 400, the common electrode 600, the color filter 700, the second substrate 800, and the second polarizing plate 900 are sequentially laminated. The alignment film 400 is preferably a photoalignment film.

FIG. 9 is a schematic cross-sectional view showing one aspect of the VA mode liquid crystal display device in the present invention, in which an alignment film is formed in a liquid crystal layer of a liquid crystal cell manufactured by using an alignment treatment (mask rubbing or photoalignment). The polymer network structure and the liquid crystal molecular arrangement structure are shown. A vertical alignment film slightly inclined (0.1 to 5.0 °) from the normal direction of the glass substrate is formed inside the transparent electrode of the liquid crystal cell (on the liquid crystal layer side), and the vertical alignment film and the liquid crystal are formed. The molecule has a twisted structure of approximately 90 ° between the upper and lower substrates.
The polymerizable monomers are arranged in the vertical direction under the orientation restricting force of the vertically aligned film, and the polymerizable monomers are polymerized and immobilized by UV light irradiation to form a polymer network. The polymer network formed in this way forms a polymer network over (V1) upper and lower substrates, and (V2) forms a polymer network from the upper (lower) substrate toward the liquid crystal direction, but is halfway through. V3) A polymer network is formed only near the surface of the alignment film. (Mainly in the case of a monofunctional monomer), (V4) It is presumed that the polymer networks have about four types of structures bonded to each other (not floating) in the liquid crystal layer.
It is considered that the anisotropic polymer polymer network formed in this manner is almost completely separated from the liquid crystal layer, and the liquid crystal molecules are oriented and arranged between these polymer networks. It is clearly different from the so-called polymer network type liquid crystal molecular arrangement structure in which liquid crystal molecules and polymer networks coexist and cause light scattering when no voltage is applied, and it is also an orientation maintenance layer that is unevenly distributed near the alignment film used in PSA and the like. It has a completely different structure.
As an example, the polymer network and the liquid crystal molecular arrangement structure by the method using the alignment film are shown, but even in the so-called MVA method having structures such as ribs and slits, the polymer network near the substrate interface and the pretilt of the liquid crystal molecules are formed. It differs only slightly depending on the diagonal electric field strength applied through the structure and the slit, and it is presumed that the structure essentially has the structure shown in the above figure.
In a VA type liquid crystal display device having such a polymer network and a liquid crystal molecule arrangement by liquid crystal molecules, the anchoring force for the liquid crystal molecules when no voltage is applied is due to the synergistic action of the anchoring force of the liquid crystal alignment film and the polymer network. It acts more strongly, and as a result, it becomes possible to increase the response speed when the voltage is off.

(Horizontal / diagonal electric field type)
As a new display technology that can divide the liquid crystal display area by a simple method such as devising the electrode structure without performing complicated processes such as mask rubbing and mask exposure on the alignment film, the oblique electric field and the transverse electric field are liquid crystal. A method of acting on the layer has been proposed.
FIG. 10 is a plan view schematically showing the smallest unit structure in a single pixel PX of a TFT liquid crystal display element using the above technique. The structure and operation of the horizontal / diagonal electric field mode liquid crystal display device will be briefly described below.
The pixel electrode PE has a main pixel electrode PA and a sub pixel electrode PB. These main pixel electrode PA and sub-pixel electrode PB are electrically connected to each other, and both the main pixel electrode PA and the sub-pixel electrode PB are provided in the array substrate AR. The main pixel electrode PA extends along the second direction Y, and the sub-pixel electrode PB extends along the first direction X, which is different from the second direction Y. In the illustrated example, the pixel electrode PE is formed in a substantially cross shape. The sub-pixel electrode PB is coupled to a substantially central portion of the main pixel electrode PA and extends from the main pixel electrode PA on both sides thereof, that is, toward the left side and the right side of the pixel PX. These main pixel electrode PA and sub pixel electrode PB are substantially orthogonal to each other. The pixel electrode PE is electrically connected to a switching element (not shown) in the pixel electrode PB.

The common electrode CE has a main common electrode CA and a sub-common electrode CB, and these main common electrode CA and the sub-common electrode CB are electrically connected to each other. The common electrode CE is electrically insulated from the pixel electrode PE. In the common electrode CE, at least a part of the main common electrode CA and the sub common electrode CB is provided on the counter substrate CT. The main common electrode CA extends along the second direction Y. The main common electrode CA is arranged on both sides of the main pixel electrode PA. At this time, in the XY plane, none of the main common electrode CAs overlap with the main pixel electrode PA, and substantially equal intervals are formed between each of the main common electrode CAs and the main pixel electrode PA. There is. That is, the main pixel electrode PA is located substantially in the middle of the adjacent main common electrode CA. The sub-common electrode CB extends along the first direction X. The sub-common electrode CB is arranged on both sides of the sub-pixel electrode PB. At this time, in the XY plane, none of the sub-common electrode CB overlaps with the sub-pixel electrode PB, and substantially equal intervals are formed between each of the sub-common electrode CB and the sub-pixel electrode PB. There is. That is, the sub-pixel electrode PB is located substantially in the middle of the adjacent sub-common electrode CB.
In the illustrated example, the main common electrode CA is formed in a band shape extending linearly along the second direction Y. The sub-common electrode CB is formed in a band shape extending linearly along the first direction X. Two main common electrodes CA are arranged in parallel at intervals along the first direction X. In the following, in order to distinguish them, the main common electrode CA on the left side in the figure is referred to as CAL, and the figure shows. The main common electrode on the right side of the inside is called CAR. Further, two sub-common electrodes CB are arranged in parallel at intervals along the second direction Y. In the following, in order to distinguish them, the upper main common electrode in the figure is referred to as CBU, and the figure shows. The lower main common electrode inside is called CBB. The main common electrode CAL and the main common electrode CAR have the same potential as the sub common electrode CBU and the sub common electrode CBB. In the illustrated example, the main common electrode CAL and the main common electrode CAR are connected to the sub common electrode CBU and the sub common electrode CBB, respectively.
The main common electrode CAL and the main common electrode CAR are arranged between the pixel PX and the pixels adjacent to the left and right, respectively. That is, the main common electrode CAL is arranged across the boundary between the illustrated pixel PX and the pixel on the left side thereof (not shown), and the main common electrode CAR is arranged on the pixel PX shown on the right side (not shown). ) Is placed across the boundary. The sub-common electrode CBU and the main common electrode CBB are arranged between the pixel PX and vertically adjacent pixels, respectively. That is, the sub-common electrode CBU is arranged across the boundary between the illustrated pixel PX and the pixel above it (not shown), and the sub-common electrode CBB is the illustrated pixel PX and the pixel below it (not shown). It is arranged across the boundary with the pixel.

In the illustrated example, in one pixel PX, four regions partitioned by the pixel electrode PE and the common electrode CE are formed as openings or transmission portions that mainly contribute to display. In this example, the initial orientation direction of the liquid crystal molecule LM is a direction substantially parallel to the second direction Y. The first alignment film AL1 is arranged on the surface of the array substrate AR facing the opposite substrate CT, and extends over substantially the entire active area ACT. The first alignment film AL1 covers the pixel electrode PE and is also arranged on the second interlayer insulating film 13. Such a first alignment film AL1 is formed of a material exhibiting horizontal orientation. In addition, the array substrate AR may further include a first main common electrode and a first sub-common electrode as a part of the common electrode.
FIG. 11 is a schematic view of the electrode structure of the 8-divided diagonal electric field mode liquid crystal cell. By dividing one pixel into eight in this way, a wider viewing angle can be realized.
Next, the operation of the liquid crystal display panel having the above configuration will be described. When no voltage is applied to the liquid crystal layer, that is, when there is no electric field formed between the pixel electrode PE and the common electrode CE (when the electric field is off), the liquid crystal layer is shown by a broken line in FIG. The liquid crystal molecule LM of LQ is oriented so that its major axis faces the first alignment treatment direction PD1 of the first alignment film AL1 and the second orientation treatment direction PD2 of the second alignment film AL2. Such an OFF time corresponds to the initial orientation state, and the orientation direction of the liquid crystal molecule LM at the OFF time corresponds to the initial orientation direction. Strictly speaking, the liquid crystal molecule LM is not always oriented parallel to the XY plane, and is often pretilted. Therefore, the strict initial orientation direction of the liquid crystal molecule LM is a direction in which the orientation direction of the liquid crystal molecule LM at the time of OFF is projected onto the XY plane.

The first orientation treatment direction PD1 and the second orientation treatment direction PD2 are both directions substantially parallel to the second direction Y. When OFF, the liquid crystal molecule LM is initially oriented so that its long axis faces a direction substantially parallel to the second direction Y, as shown by the broken line in FIG. That is, the initial orientation direction of the liquid crystal molecule LM is parallel to the second direction Y (or 0 ° with respect to the second direction Y).
As shown in the illustrated example, when the first orientation treatment direction PD1 and the second orientation treatment direction PD2 are parallel and have the same orientation, the liquid crystal molecules LM are substantially horizontal in the vicinity of the intermediate portion of the liquid crystal layer LQ in the cross section of the liquid crystal layer LQ. It is oriented in (pretilt angle is substantially zero), and is oriented with a pretilt angle that is symmetrical in the vicinity of the first alignment film AL1 and the vicinity of the second alignment film AL2 with this as a boundary (spray orientation). In the state where the liquid crystal molecules LM are spray-oriented in this way, the liquid crystal molecules LM in the vicinity of the first alignment film AL1 and the liquid crystal molecules LM in the vicinity of the second alignment film AL2 are present even in the direction inclined from the normal direction of the substrate. Is optically compensated by. Therefore, when the first orientation processing direction PD1 and the second orientation processing direction PD2 are parallel to each other and have the same orientation, there is little light leakage in the case of black display, and a high contrast ratio can be realized. It is possible to improve the quality. When the first alignment treatment direction PD1 and the second orientation treatment direction PD2 are parallel and opposite to each other, the liquid crystal molecule LM is located in the vicinity of the first alignment film AL1 and the second alignment film AL2 in the cross section of the liquid crystal layer LQ. Orientation with a substantially uniform pretilt angle in the vicinity of and in the middle portion of the liquid crystal layer LQ (homogeneous orientation). A part of the backlight light from the backlight 4 passes through the first polarizing plate PL1 and is incident on the liquid crystal display panel LPN. The light incident on the liquid crystal display panel LPN is linearly polarized light orthogonal to the first polarization axis AX1 of the first polarizing plate PL1. The polarization state of such linearly polarized light hardly changes when passing through the liquid crystal display panel LPN at the time of OFF. Therefore, the linearly polarized light transmitted through the liquid crystal display panel LPN is absorbed by the second polarizing plate PL2, which has a cross-nicol positional relationship with respect to the first polarizing plate PL1 (black display).

On the other hand, in a state where a voltage is applied to the liquid crystal layer LQ, that is, in a state where a potential difference is formed between the pixel electrode PE and the common electrode CE (when ON), a substrate is formed between the pixel electrode PE and the common electrode CE. A lateral electric field (or diagonal electric field) substantially parallel to the above is formed. The liquid crystal molecule LM is affected by the electric field, and its long axis rotates in a plane substantially parallel to the XY plane as shown by the solid line in the figure.
In the example shown in FIG. 10, the liquid crystal molecule LM in the lower half region of the region between the pixel electrode PE and the main common electrode CAL rotates clockwise with respect to the second direction Y and is shown in the figure. The liquid crystal molecule LM in the region of the upper half is rotated counterclockwise with respect to the second direction Y and is oriented so as to face the upper left in the figure. Of the region between the pixel electrode PE and the main common electrode CAR, the liquid crystal molecule LM in the lower half region rotates counterclockwise with respect to the second direction Y and faces the lower right in the figure. Oriented, the liquid crystal molecule LM in the upper half region rotates clockwise with respect to the second direction Y and is oriented so as to face the upper right in the figure. In this way, in the state where an electric field is formed between the pixel electrode PE and the common electrode CE in each pixel PX, the orientation direction of the liquid crystal molecule LM is divided into a plurality of directions with the position overlapping with the pixel electrode PE as a boundary. , Form a domain in each orientation direction. That is, a plurality of domains are formed in one pixel PX.
At the time of such ON, the linearly polarized light orthogonal to the first polarization axis AX1 of the first polarizing plate PL1 is incident on the liquid crystal display panel LPN, and the polarization state is the orientation of the liquid crystal molecule LM when passing through the liquid crystal layer LQ. It changes according to the state. At such an ON state, at least a part of the light that has passed through the liquid crystal layer LQ passes through the second polarizing plate PL2 (displayed in white). According to such a structure, four domains can be formed in one pixel, so that the viewing angles in four directions can be optically compensated, and a wide viewing angle can be achieved. Therefore, it is possible to realize a display with high transmittance without gradation inversion, and it is possible to provide a liquid crystal display device having good display quality. Further, by setting the area of the opening to be substantially the same for each of the four regions partitioned by the pixel electrode PE and the common electrode CE in one pixel, the transmittance of each region becomes substantially the same, and each opening The light transmitted through the portions optically compensates for each other, and it becomes possible to realize a uniform display over a wide viewing angle range.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples. In addition, "%" in the compositions of the following Examples and Comparative Examples means "mass%".

[Example 1]
As a P-type liquid crystal composition, a composition (Δn0.103, viscosity η20 mPa · s, Vth 1.72 Vrms) shown in the following (LCP-1) was prepared. As the polymerizable compound, a compound represented by the following formula (V1-1-1) was used.
The polymerizable liquid crystal composition (LCM-1) contains 97% of the P-type liquid crystal composition (LCP-1), 2.94% of the polymerizable compound (V1-1-1), and 0.06% of the polymerization photoinitiator Irgacure651. ) Was prepared. After heating the solid polymerizable compound (V1-1-1) to 60 ° C. and dissolving it in the liquid crystal (LCP-1), the polymerizable compound (V1-1-1) is uniformly dissolved at room temperature and nematic. It was confirmed by a polarizing microscope that it showed a liquid crystal phase.
A parallel rubbing oriented cell with ITO coated with a polyimide alignment film having a cell gap of 3 μm was used so that a uniaxial orientation (homogeneous orientation) of the liquid crystal could be obtained. The polymerizable liquid crystal composition (LCM-1) was injected into the glass cell by a vacuum injection method.

After the injection, the glass cell was taken out, and the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) were irradiated at 25 ° C. for 300 seconds. As a result, the polymerizable compound in the polymerizable liquid crystal composition was polymerized to obtain an ECB mode liquid crystal display device. It was confirmed that when the cells produced between the two orthogonal polarizing plates were placed so that the rubbing processing direction and the polarization axis direction coincided with each other, a dark field was obtained and uniaxial orientation was obtained.
When the voltage-transmittance characteristic was measured by applying a rectangular wave of 60 Hz, the drive voltage V90 was 14.6 Vrms.

Next, the response time in ECB mode was examined. As a result, it was confirmed that the speed of τd was increased from 5 ms in LCP-1 to 2.7 ms. On the other hand, as the concentration of the polymerizable compound in the polymerizable liquid crystal composition increased, τr at the same drive voltage tended to be slightly slower, but it was confirmed that the overall response of τr + τd became faster.
The polymerizable liquid crystal composition used for cell preparation was left at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

[Example 2]
A polymerizable compound (V1-1-1) containing 95% of the P-type liquid crystal composition (LCP-1; Δn0.103, viscosity η20 mPa · s), 5% of the polymerizable compound (V1-1-1) and the polymerization photoinitiator Irgacure651. ), A polymerizable liquid crystal composition (LCM-2) containing 2% was prepared.
A parallel rubbing oriented cell with ITO coated with a polyimide alignment film having a cell gap of 3.5 μm was used so that a uniaxial orientation (homogeneous orientation) of the liquid crystal could be obtained. The polymerizable liquid crystal composition (LCM-1) was heated to 60 ° C., dissolved in LCP-1, and injected into a glass cell by a vacuum injection method.
After the injection, the glass cell was taken out, and the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) were irradiated at 25 ° C. or −10 ° C. for 300 seconds. As a result, the polymerizable compound in the polymerizable liquid crystal composition was polymerized to obtain an ECB mode liquid crystal display device.
When a voltage-transmittance characteristic was measured by applying a 60 Hz square wave to a liquid crystal display element obtained by polymerizing at 25 ° C. or -10 ° C., the drive voltage V90 was 17.0 Vrms in the polymerization at 25 ° C. It was confirmed that the drive voltage V90 became 27 Vrms in the polymerization at −10 ° C. and the drive voltage increased due to the low temperature polymerization.

Next, the response time in ECB mode was examined. In the polymerization at 25 ° C., τd was 1.4 ms, and in the polymerization at −10 ° C., τd was 0.7 ms, and it was confirmed that the speed of τd was increased by low temperature polymerization. On the other hand, at τr at the same drive voltage, τr becomes 1.1 ms in the polymerization at 25 ° C., and τd becomes 0.9 ms in the polymerization at −10 ° C., and the liquid crystal obtained by polymerizing at −10 ° C. It was confirmed that the response speed of the display element was higher than that in the case of polymerization at 25 ° C.

[Example 3]
As an N-type liquid crystal composition, a composition (Δn0.102, viscosity η16.8, Δε-3.8) shown by the following (LCN-1) was prepared. A compound represented by the formula (V1-1-1) was used as the polymerizable compound.
98% as N-type liquid crystal composition (LCN-1; Δn0.102, viscosity η16.8, Δε-3.8), 1.96% polymerizable compound (V1-1-1), and polymerization photoinitiator Irgacure651. Was prepared in a polymerizable liquid crystal composition (LCM-3) containing 0.04% of the polymerizable compound (V1-1-1).
After applying a polyimide alignment film with a cell gap of 3 μm so that vertical orientation (homeotropic orientation) of the liquid crystal can be obtained, rubbing orientation treatment is performed so that the pretilt angle is 1 ° to 2 ° with respect to the substrate surface normal direction. A cell having a parallel rubbing orientation with ITO was used. After heating the solid polymerizable compound (V1-1-1) to 60 ° C. and dissolving it in the liquid crystal (LCN-1), the polymerizable compound (V1-1-1) is uniformly dissolved at room temperature and nematic. It was confirmed by a polarizing microscope that it showed a liquid crystal phase. The polymerizable liquid crystal composition (LCM-3) was heated to 60 ° C. and injected into a glass cell by a vacuum injection method.
After the injection, the glass cell was taken out, and the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) were irradiated at 25 ° C. for 300 seconds. As a result, the polymerizable compound of the polymerizable liquid crystal composition was polymerized to obtain a VA mode liquid crystal display device. When the prepared cell is placed between two orthogonal polarizing plates, it turns black and the dark field does not change even if the cell is rotated in the azimuth direction, and the optical axis direction of the polymer network and the liquid crystal orientation easy axis direction are the same direction. It was confirmed.

A 60 Hz square wave was applied and the voltage-transmittance characteristics and response time were measured. As a result, the drive voltage V90 was 11.3 Vrms, τd was 2.3 ms, τr was 1.2 ms, and the cell response time using only the N-type liquid crystal composition LCN-1 (τd: 5.3 ms, τr: 7.1 ms). , Drive voltage V90: 7.9 Vrms), it was confirmed that the speed was increased. Further, the gate was turned on at intervals of 60 Hz, a voltage of 1 V was applied to the cell for 16.6 milliseconds, and after the gate was turned off, the voltage held by the cell was measured to obtain the voltage holding rate. The voltage holding rate at 25 ° C. was 99.7%, and the voltage holding rate at 70 ° C. was 95.4%.
The polymerizable liquid crystal composition used for cell preparation was left at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

[Examples 4 to 11, Comparative Examples 1 to 3]
(LCN-1) and (LCN-2) were used as the N-type liquid crystal composition, and the compounds represented by (V1-1-1) to (V1-1-5) were used as the polymerizable compounds in Table 1 below. The polymerizable liquid crystal composition was prepared by adding the polymerization photoinitiator Irgacure 651 so as to be 2% with respect to each polymerizable compound. A VA mode liquid crystal cell was produced in the same manner as in Example 3.
As a result, the polymerizable compound of the polymerizable liquid crystal composition was polymerized to form a phase-separated structure in the entire cell, and a VA mode liquid crystal display element was obtained.
The polymerizable liquid crystal composition used for cell preparation was left at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

A 60 Hz square wave was applied to the VA mode of the prepared cell, and the voltage-transmittance characteristics and response time were measured. Each characteristic is shown in Table 1. Comparative Example 1 in Table 1 shows a drive voltage V90, a fall time, and a rise time when the liquid crystal composition (LCN-1) is 100%. Comparative Example 2 shows a drive voltage V90, a fall time, and a rise time when the liquid crystal composition (LCN-2) is 100%. Comparative Example 3 shows the case where (V1-1-2) was added in a small amount of 0.5%. In this case, the rise time is longer than that of the liquid crystal compositions of Comparative Example 1 and Comparative Example 2 and the response time is not improved, but the polymerizable compound (V1-1-2) of Example 4 is used. When it is set to 1%, both the fall time and the rise time are shortened and the responsiveness is improved. Further, when the addition amount of (V1-1-1) or (V1-1-2) is increased, the falling time and the rising time are shortened, and the responsiveness is greatly improved. Further, even in the combination with (V1-1-3), (V1-1-4), and (V1-1-5), the falling time and the rising time are shortened, and the responsiveness is greatly improved. It was confirmed.

When the prepared cell is placed between two polarizing plates that are orthogonal to each other using a polarizing microscope, a dark field is created, and even if the cell is rotated in the azimuth direction, the black level in the dark field does not change. It was confirmed that the mesogen groups constituting the polymer network were homeotropically oriented, and the optical axis direction of the polymer network and the easy axial direction of the liquid crystal orientation were formed so as to be orthogonal to the cell surface. It was confirmed that the anchoring force of the polymer network formed so as to coincide with the optical axis direction of the polymer network and the easy axis of liquid crystal orientation acts to shorten the fall time. Further, the drive voltage is increased due to the effect of the anchoring force of the polymer network, but at the same time, the rise time is shortened due to the electric field effect, and the responsiveness is improved. The fall time is greatly affected by the rotational viscosity and elastic constant of the liquid crystal, but when a polymer network with optical anisotropy is formed in the liquid crystal, the fall time is improved by the anchoring force from the polymer network. It is useful as a display material for displays with good responsiveness.

[Example 12]
On the side of the pair of glass substrates on which the ITO electrodes are formed, the resist LC-200 manufactured by Shipley Co., Ltd. alternately has banks (projections) having a height of 1.5 μm and a width of 10 μm so as to have a gap of 37.5 μm. An MVA mode liquid crystal panel having a cell gap of 3.5 μm was produced. A polyimide alignment film was applied and then fired to form a vertical alignment film so that the vertical alignment (homeotropic orientation) of the liquid crystal could be obtained. The drive mode is a normally black mode in which the polarizer arranged on the outside of the upper and lower glass substrates is a cross Nicol.
The above (LCN-1) was used as the N-type liquid crystal composition, and 1 to 5% of each compound represented by the formula (V1-1-1) was added as a polymerizable compound in 1% increments to obtain a polymerizable liquid crystal composition. It was adjusted. The polymerizable liquid crystal composition was heated to 60 ° C. and injected into a glass cell by a vacuum injection method, the liquid crystal cell was taken out, and the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Next, with an AC square wave voltage of 64 Hz below the threshold voltage (1 V) applied to the liquid crystal layer, the ultraviolet (UV) intensity is 20 mW / emitted through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics). A liquid crystal panel having a polymer network type MVA structure was produced by irradiating with ultraviolet rays of cm ² for 60 seconds at 25 ° C. for 60 seconds to polymerize a photopolymerizable monomer. A 60 Hz square wave was applied to the prepared panel, and the voltage-transmittance characteristics and response time were measured.

The fall time τd and the rise time τr were measured by applying a rectangular wave voltage of 60 Hz that gives V90. When a small amount of the compound represented by the formula (V1-1-1) was added between 1% and 3%, the fall time was shortened and the responsiveness was improved. It was confirmed that the fall time was shortened by the effect of the anchoring force of the polymer network formed so as to coincide with the optical axis direction of the polymer network and the easy axis of liquid crystal orientation. Further, as the drive voltage increases, the rise time becomes shorter and the responsiveness is improved. The fall time is greatly affected by the rotational viscosity and elastic constant of the liquid crystal, but when a polymer network with optical anisotropy is formed in the liquid crystal, the fall time is improved by the anchoring force from the polymer network. It is useful as a display material for displays with good responsiveness.

When a liquid crystal panel having a polymer network type MVA structure created in this way is placed between a polarizing microscope in which two polarizers are orthogonal to each other, a black display is observed, and even if the cell is rotated in the azimuth direction, black appears. It was confirmed that there was no change and that the optical axis direction of the polymer network and the easy axis direction of liquid crystal orientation were the same direction.
When observing the liquid crystal panel with a polarizing microscope between the cross Nicols while applying a voltage equal to or higher than the threshold voltage, four dispersion lines appear in the boundary region of the orientation that seems to be divided into orientations. It was observed that it was. Since the dispersion line is generated by the disorder of the liquid crystal molecular arrangement, it can be confirmed that one pixel is divided into four by this.
It was confirmed that the optical axis direction and the liquid crystal orientation were formed so as to be orthogonal to the cell surface. It was confirmed that the fall time was shortened by the effect of the anchoring force of the polymer network formed so as to match the optical axis direction of the polymer network with the easy axis of liquid crystal orientation. Further, as the drive voltage increases, the rise time becomes shorter and the responsiveness is improved. The same evaluation was performed on a cell having a rib structure on one of the substrates and an ITO slit structure on the opposite substrate side, but no significant difference in display characteristics was observed.

[Example 13]
A photoalignment film coating solution having a 4-chalcone group was applied to the first substrate and the second substrate by a spin casting method, and then fired at 180 ° C. for 60 minutes to form an alignment film. Subsequently, the alignment treatment by light irradiation was carried out by irradiating the alignment film with P-polarized light having an incident angle of 40 degrees and a wavelength of 365 nm for 400 seconds at an intensity of 3 mW / cm ² along the orientation orientation shown in FIG.
When the pretilt angle was measured, the pretilt angle of the liquid crystal molecules in the vicinity of the first alignment film and the vicinity of the second alignment film was 88.5 °. The constituent molecules of the alignment film have a 4-calcon photofunctional group (photosensitive group) in the side chain of the polymer chain, and by this photoalignment treatment, the photofunctional group forms a dimer by a dimerization reaction. A crosslinked structure was formed. In this embodiment, each pixel of the first substrate was divided into two orientation processing regions, and light irradiation was performed from opposite directions. Further, each pixel of the second substrate was similarly divided into two orientation processing regions, and light irradiation was performed from opposite directions. Then, after forming a seal, spraying a spacer, and the like, in the substrate bonding step, the first substrate and the second substrate were bonded so that the orientation processing directions were orthogonal to each other. As a result, four domain regions having different twist directions of the liquid crystal molecules were formed in each pixel.

A polymerizable liquid crystal composition obtained by adding 1%, 2%, 3%, 10%, and 20% of a compound represented by the above formula (V1-1-1) to an N-type liquid crystal composition (LCN-1). Was adjusted. Next, after injecting and sealing the polymerizable liquid crystal composition into the liquid crystal panel, UV light irradiation was performed to prepare a VATN type polymer network liquid crystal display panel by photoalignment treatment. The cell gap was 3.5 μm. The voltage-transmittance characteristics and response speed of the obtained liquid crystal panel were measured. In both cases, the fall time was faster. In the region where the amount of the polymerizable monomer added is 1% to less than 2%, the fall time increases as the amount of the monomer added increases, but the rise time is affected by the rise of the V90 voltage (saturation voltage). It tended to be a little slower, but when the addition amount was 2% or more, the liquid crystal molecular arrangement structure was properly aligned, and the rise response speed was also increased. When the addition amount is further increased to 10%, the influence of the orientation regulating force of the polymer network becomes remarkable, and the fall time is 0.6 ms, which is about 1/7 of 4.2 ms when the polymerizable monomer is not added. , An extremely fast fall response time was obtained. The rise time is also affected by the higher drive voltage, but 0.9 ms, which is more than four times faster than when no polymerizable monomer is added, is the total of the rise time and fall time. It was confirmed that (τr + τd) also had a high-speed response of 1.5 ms, which was 12.4 ms when no polymerizable monomer was added.

When the prepared cell is placed between two orthogonal polarizing plates, a black display is observed, the black does not change even if the cell is rotated in the azimuth direction, and the optical axis direction of the polymer network and the easy axis direction of liquid crystal orientation are the same. I confirmed that. While applying a voltage equal to or higher than the threshold voltage to this liquid crystal panel, insert one λ / 4 wavelength plate between the cross Nicols and rotate it in the same way as above, during one rotation of dark, light, dark, and light. It was observed that the shaded state appeared four times in order, and it was confirmed that one pixel was neatly divided into four.

[Example 14]
A VA type liquid crystal cell having a PVA electrode structure having slit structures alternately in the ITO transparent electrodes of the upper and lower substrates was produced. The distance between the slits and the electrode width were 5 μm each. A vertically oriented film (polyimide material) was formed on these substrates by a printing method, and heat treatment was performed at 180 ° C. for 60 minutes. These two glass substrates were bonded together via a spacer having a diameter of 3.5 μm to prepare an empty cell. The above formula (LCN-1) was used as the N-type liquid crystal composition, and 2% and 10% of the compound represented by the formula (V1-1-1) were added as the polymerizable compound to prepare a polymerizable liquid crystal composition, respectively. The PVA liquid crystal panel having a polymer network structure was prepared in the same manner. The voltage-transmittance characteristics and response time of the obtained liquid crystal panel were measured. In both cases, the fall time has been increased. Further, when 10% of the polymerizable monomer was added, an increase in the driving voltage was observed, but not only the falling speed but also the rising speed was increased, and an extremely high response speed of τr + τd = 1.3ms was confirmed. It was. When the prepared panel is placed between two orthogonal polarizing plates, a black display is observed, black does not change even if the panel is rotated in the azimuth direction, and the optical axis direction of the polymer network and the easy axis direction of liquid crystal orientation are the same. I confirmed that. When observing with a polarizing microscope between cross Nicols in the same manner as above while applying a voltage equal to or higher than the threshold voltage to this liquid crystal panel, four dispersion lines appear in the boundary region of the orientation that seems to be divided into orientations. It was observed that it was doing. Since the dispersion line is generated by the disorder (boundary) of the liquid crystal molecular arrangement, it can be confirmed that one pixel is divided into four by this.

[Example 15]
A test cell having the fishbone type electrode structure shown in FIG. 13 was prepared. In FIG. 13, a liquid crystal layer is sealed between two glass substrates that are bonded to each other with a predetermined cell gap. A transparent electrode made of ITO is formed on the facing surfaces of the two opposing substrates. A glass substrate having a thickness of 0.7 mm was used, and a common electrode was formed on the opposing substrate. The transparent electrode is provided with a slit portion 512c from which a part of the electrode material (ITO) is removed. A cross-shaped slit portion 512c having a width of 5 μm connecting the midpoints of the opposing sides of the rectangular cell functions as an orientation control structure, and a slit portion 512c extending diagonally 45 ° from the slit portion 512c and having a width of 5 μm pitches. A plurality of 8 μm are formed, and these function as auxiliary orientation control factors that suppress turbulence in the azimuth direction at the time of inclination. The width of the display pixel electrode is 3 μm. The pixel stem electrode 512a and the pixel branch electrode 512b have a structure in which branch electrodes are extended in four directions different by 90 degrees with the center of the pixel as the center of symmetry, while having an angle of 45 degrees. A vertical alignment film (polyimide material) was formed on these substrates by a printing method, and heat treatment was performed at 180 ° C. for 60 minutes. These two glass substrates were bonded together via a spacer having a diameter of 3.5 μm to prepare an empty cell in which no liquid crystal was injected.

The above formula (LCN-1) is used as the N-type liquid crystal composition, and 20% of the compound represented by the formula (V1-1-2) is added to prepare a polymerizable liquid crystal composition to prepare a fishbone having a polymer network structure. A mold VA liquid crystal panel was produced. In addition, the voltage-transmittance characteristics and response speed of the fishbone type VA liquid crystal panel injected with the formula (LCN-1) to which no polymerizable monomer was added were measured. It was possible to obtain a liquid crystal display device having an extremely high responsiveness of τr + τd = 1.1 ms, with both a short fall time and a short rise time. When the prepared cell is placed between two orthogonal polarizing plates, a black display is observed, the black does not change even if the cell is rotated in the azimuth direction, and the optical axis direction of the polymer network and the easy axis direction of liquid crystal orientation are the same. I confirmed that.
When observing with a polarizing microscope between cross Nicols in the same manner as above while applying a voltage equal to or higher than the threshold voltage to this liquid crystal panel, four dispersion lines appear in the boundary region of the orientation that seems to be divided into orientations. It was observed that it was doing. Since the dispersion line is generated by the disorder of the liquid crystal molecular arrangement, it can be confirmed that the dispersion line is oriented and divided into four domains in one pixel.

[Example 16]
A test liquid crystal cell capable of operating in the lateral / oblique electric field mode shown in FIG. 14 was produced, and various electro-optic special products were evaluated.
A window frame-shaped transparent electrode substrate having an electrode width of 10 μm was produced by a photoetching method using a transparent glass substrate having an ITO transparent electrode layer having a thickness of 0.7 mm formed by a sputtering method. A polyimide alignment film was applied and fired on the glass substrate on which the window frame-shaped ITO electrode of the lower first glass substrate and the upper second glass substrate was formed, and then the rubbing alignment treatment was performed.
The rubbing direction of the first glass substrate was from the bottom to the top in the figure, and the second glass substrate side arranged to face each other was also rubbed in the same direction (from the bottom to the top in the figure) to achieve parallel orientation. By such an orientation treatment method, the liquid crystal molecules take a spray-oriented state. Next, the ITO transparent electrode of the black lattice portion of the lower first glass substrate and the ITO transparent electrode of the diagonal line lattice portion of the upper second glass substrate side are arranged to face each other so as to have a pitch of 25 μm with a deviation of exactly half a pitch. They were laminated with a thermosetting adhesive via a .5 μm spherical spacer.
By such a combination of electrodes, the black lattice electrode corresponds to the main electrode, the sub-pixel electrode, and the shaded portion corresponding to the main pixel electrode and the sub-pixel electrode, respectively, so that the central portion of the shaded electrode is divided into four characters. It functions as a main common electrode and a sub common electrode, and is divided into four display regions having a display region of 15 μm × 15 μm.

The P-type liquid crystal composition (Δn = 0.103, viscosity η = 20 mPa · s, Δε = 7.5) represented by the above formula (LCP-1) is expressed by the formula (V1-1-1) in 98% by weight. 2.0% by weight of the compound to be added is further added, and 2.0% by weight of the polymerization photoinitiator Irgacure651 is added to the compound represented by the formula (V1-1-1), and the mixture is heated to 60 ° C. The polymerizable liquid crystal composition was prepared by dissolving it in the liquid crystal composition. The obtained polymerizable liquid crystal composition was injected into the liquid crystal cell by a vacuum injection method. After injecting the liquid crystal, the liquid crystal cell was taken out, and the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) are irradiated at 25 ° C. for 300 seconds to polymerize the polymerizable compound in the polymerizable liquid crystal composition. A liquid crystal display element in an oblique electric field mode was obtained. Further, a liquid crystal display element in an oblique electric field mode was obtained in the same manner except that the amount of the compound represented by the formula (V1-1-1) was set to 3.0% by weight. When the obtained liquid crystal cell is placed on the stage of a polarizing microscope in a cross Nicol state in a state where no voltage is applied in a direction in which the rubbing processing direction and the polarization axis direction coincide with each other, a dark field (normally black) is obtained and uniaxial orientation is obtained. It was confirmed that the sex was obtained. As the amount of the photopolymerizable monomer added increases, both the threshold voltage and the saturation voltage increase, but the increase in the saturation voltage becomes particularly large, and the rise of the voltage-transmittance characteristic becomes gentle. It was confirmed that the saturation voltage of the liquid crystal cell to which 3% of the photopolymerizable monomer was added shifted from 3.29V when no addition was added to 5.47V to the high voltage side by 2V or more.

However, in reality, for example, in the case of a liquid crystal TV, the maximum drive voltage is around 15 V, and if the saturation voltage of the liquid crystal display element is less than this, there is no particular problem. As the amount of the polymerizable monomer added increased, both Tr and Td responded at high speed. From this, it is considered that a high-speed response display suitable for moving images such as animations, action movies, and sports programs was obtained. When the saturation voltage of the liquid crystal display element is 15 V or less, even if the amount of the polymerizable functional group added is a little large, a great advantage can be enjoyed in terms of high-speed moving image display. The rising response rate of τr tends to be slightly slower as the amount of the photopolymerizable monomer added increases, but it is considered that there is no problem in terms of display characteristics. On the other hand, the falling speed τd became faster as the amount of the photopolymerizable monomer added increased, and the response was 5 to 6 ms when no photopolymerizable monomer was added, but increased to 3 to 4 ms by adding 2% by weight to 3 weight. With the addition of%, the time was shortened to about 1/2 to 2 to 3 ms, and the response was accelerated by the action of the anchoring force of the polymer network formed in the same direction as the initial alignment film by light irradiation. It was confirmed that it was done.

After confirming that the obtained liquid crystal cell becomes normally black by placing it in a direction in which the partial processing direction in the cross Nicol state and the polarization axis direction coincide with each other in a state where no voltage is applied, a saturation voltage is applied to the liquid crystal cell. Was observed. An XY stage was installed in a polarizing microscope, and each display region divided into four orientations was observed, but they were optically equivalent and could not be distinguished at all. Even when a voltage intermediate between the threshold and the saturation voltage was applied, the state was completely optically equivalent. Next, one region out of the four display regions was selected, and the stage of the polarizing microscope was rotated while applying the above-mentioned intermediate voltage to search for the darkest position and fix the angle. In such a state, the other three different regions were observed while moving the XY stage in the X and Y directions. It was observed that the area 180 degrees different from the initially set area had almost the same darkness, and the area 90 degrees different from the initially set area was gray. .. As a result, it was confirmed that the arrangement direction of the liquid crystal molecules was different between the fixed region and the region different by 90 degrees or 270 degrees, and it was confirmed that the orientation division was properly performed. Further, the liquid crystal cells used in this example have undergone parallel alignment treatment, and the liquid crystal molecules are in a spray-oriented state. Therefore, the molecules in the center of the liquid crystal layer are oriented substantially parallel to the liquid crystal substrate by applying a voltage, and the liquid crystal molecules are arranged vertically with the central part as a boundary while being rotated by an oblique electric field, so that it is just like a double STN panel. It was confirmed that the phase difference was completely compensated and the viewing angle dependence was eliminated.

In this embodiment, a liquid crystal composition having a positive dielectric anisotropy was used, and its operation and electro-optical characteristics were evaluated and confirmed in the liquid crystal cell shown in FIG. 14, but in the case of an actual TFT liquid crystal display panel, A part or all of the pixel electrode and the common electrode are formed on the TFT substrate side via a one-layer insulating film, and a part or all of the common electrode is formed on the opposite substrate side. Since the lateral electric field effect acts on the liquid crystal molecules at the same time, the same effect as in this example can be obtained even if a liquid crystal composition having a negative dielectric anisotropy is used. In that case, the orientation processing direction may be either anti-parallel orientation or parallel orientation.
Further, in this embodiment, the rubbing method is used as the alignment treatment method, but since the electrode structure and the wiring structure on the TFT substrate side are extremely complicated and have many steps, the entire surface of the alignment film is uniformly uniform by the rubbing method. The photo-alignment treatment method is particularly preferable because it is difficult to obtain a good surface orientation, dust and fluff generated by rubbing, and destruction of the TFT due to charging during rubbing occur. As the photoalignment treatment method, a photodegradable polyimide using UV light near 254 nm is used, or a photoalignment treatment using a polymer that causes photodimerization having a photofunctional group such as cinnamic acid or coumarin by light near 313 nm, or It is preferable to use an azo-based photoalignment polymer that causes photoisomerization by light in the vicinity of 365 nm.
As described above, the bifunctional monomer is added to the liquid crystal composition having positive or negative dielectric anisotropy in the liquid crystal display device of the transverse electric field method (IPS mode, FFS mode) having any structure. Then, by irradiating with UV light, a nanophase separation reaction is induced, and a polymer network is formed in a direction substantially the same as the parallel orientation direction due to the initial orientation by the liquid crystal alignment film, and the anchoring force and the initial vertical orientation of the polymer network are formed. It was confirmed that the response speed of the transverse electric field type liquid crystal display device, particularly the response speed at the time of falling of the liquid crystal, is increased by the synergistic action of the anchoring force of.

[Example 17]
FIG. 15 is a plan view showing the electrode structure of the IPS mode evaluation test cell used for confirming the effect of the present invention and a schematic plan view showing the molecular arrangement of the liquid crystal. After forming an ITO film on a glass substrate with a thickness of 0.7 mm, strip-shaped electrodes with a width of 10 μm, which are symmetrically doglegged in the opposite directions at the center by etching, are placed at intervals of 10 μm. It was formed from the vertical direction of. The common electrode and the pixel electrode are formed on the same substrate plane, the common electrode portion is outlined, and the pixel electrode portion is shown by diagonal lines. The common electrode and the pixel electrode have a comb tooth electrode structure arranged so as to be staggered, and the comb tooth electrode has an inclination of 15 degrees in the left-right direction with respect to the vertical direction of the paper surface. , It has a comb tooth electrode structure oriented and divided into four regions from the first quadrant to the fourth quadrant, and this was used as the first substrate (L / s = 10 μmm / 10 μm).
A polyimide alignment film is applied and fired on a second substrate (not shown) having a glass thickness of 0.7 mm and no transparent electrode, which is arranged opposite to the first substrate via a 3.5 μm spherical spacer, and then rubbing. Orientation treatment was performed. The rubbing direction of the first substrate was from the bottom to the top in the figure, and the second substrate side arranged to face each other was rubbed in the opposite direction (from the top to the bottom in the figure) to achieve antiparallel orientation. The angle between the two comb tooth electrode groups and the rubbing orientation direction was 15 °. The polarizer and the analyzer are arranged outside the test cell in a cross Nicol state, and the transmission axis or the polarization axis of the polarizer is arranged parallel to or perpendicular to the initial orientation direction of the liquid crystal molecules. As a result, in this test cell, a normally black state was obtained when no voltage was applied.

A polyimide solution is applied to and fired on a first substrate having an electrode structure as shown in FIG. 15 and a second substrate having no electrode, and then rubbing treatment is performed, and they are placed facing each other using a 3.5 μm spherical silica spacer and bonded together. A test cell for IPS mode with anti-parallel orientation was created. The rubbing direction was the left-right direction (horizontal direction) of the paper surface. A mixture of 98.0% by weight of the liquid crystal composition represented by the above formula (LCN-1) and 2.0% by weight of the compound represented by the formula (V1-1-1) is heated to 60 ° C. to form a liquid crystal assembly. After being dissolved in a substance, it was injected into a liquid crystal cell by a vacuum injection method. The polymerization photoinitiator Irgacure651 is contained in an amount of 2.0% by weight based on the polymerizable compound (V1-1-1).
After injecting the liquid crystal, the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) are irradiated at 25 ° C. for 300 seconds to polymerize the polymerizable compound in the polymerizable liquid crystal composition. A liquid crystal display element in FFS mode was obtained. When placed on the stage of a cross-nicolar polarizing microscope with no voltage applied in a direction in which the rubbing processing direction and the polarization axis direction match, a dark field (normally black) is obtained and uniaxial orientation is obtained. It was confirmed.
Regarding τr, the liquid crystal composition represented by the formula (LCN-1) was 29.5 ms at 100% by weight, but 2.0% by weight of the compound represented by the formula (V1-1-1) was added. When polymerized, the response time was 15.6 ms, and the response speed was improved. Similarly, τd has a high-speed response, and the liquid crystal composition represented by the formula (LCN-1), which was 17.1 ms at 100% by weight, is represented by the formula (V1-1-1). It was confirmed that when 2.0% by weight of the compound was added and polymerized, the response was 12.3 ms and the response was high. It was confirmed that τr and τd show high-speed response even in the other drive voltage region, that is, in the halftone display.

After confirming that the liquid crystal cell is normally black by placing it between the cross-nicol polarizing plates in the direction in which the orientation processing direction and the polarization axis direction coincide with each other in a state where no voltage is applied, a saturation voltage is applied to the liquid crystal cell. Was observed. An XY stage was installed in a polarizing microscope, and each display region divided into four orientations was observed, but they were optically equivalent and could not be distinguished at all. Even when a voltage intermediate between the threshold and the saturation voltage was applied, the state was completely optically equivalent. Next, one region out of the four display regions was selected, and the stage of the polarizing microscope was rotated while applying the above-mentioned intermediate voltage to search for the darkest position and fix the angle. In such a state, the other three different regions were observed while moving the XY stage in the X and Y directions. It was observed that the region 180 degrees different from the initially set region was in a state of almost the same darkness, and the region 90 degrees different from that was in a gray state. As a result, it can be confirmed that the arrangement direction of the liquid crystal molecules is different between the region fixed at least initially and the region different by 90 degrees or 270 degrees, and it can be confirmed that the orientation division is properly performed. It was.

[Example 18]
A polyimide solution is applied to and fired on a first substrate having an electrode structure as shown in FIG. 16 and a second substrate having no electrode, and then rubbing treatment is performed, and they are placed facing each other using a 3.5 μm spherical silica spacer and bonded together. A test cell for FFS mode by antiparallel orientation was prepared (L / s = 10 μm / 30 μm). FIG. 16 is a plan view showing an electrode structure of an FFS mode test cell having a dogleg-shaped pixel electrode. A flat electrode of ITO was arranged on a 0.7 mm glass substrate, a transparent insulating layer such as SiN was provided on the flat electrode, and an ITO transparent electrode layer was sputter-deposited on the transparent insulating layer, and a pixel electrode was formed by etching. The pixel electrodes were formed in the shape of a strip having a width of 10 μm at intervals of 20 μm, and a flat electrode formed in the lower layer of the insulating film was used as a common electrode, and this was used as a first substrate. A polyimide alignment film is applied and fired on the first substrate and the second substrate (not shown) having a glass thickness of 0.7 mm, which is arranged opposite to the first substrate via a 3.5 μm spherical spacer, and then a rubbing alignment treatment is performed. It was. The rubbing direction of the first substrate was from the bottom to the top in the figure, and the second substrate side arranged to face each other was rubbed in the opposite direction (from the top to the bottom in the figure) to achieve antiparallel orientation. The angle between the two comb tooth electrode groups and the rubbing orientation direction was 15 °.
In this case as well, exactly as in the case described with reference to FIG. 15, the liquid crystal display region is oriented and divided into four regions from the first quadrant to the fourth quadrant, and each has a liquid crystal molecular arrangement having a different rotation direction. I understand. Furthermore, in the IPS mode, no voltage was applied to the liquid crystal molecules on the IPS pixel electrode and the common electrode, and the aperture ratio was low, but in the FFS mode, the voltage was also applied to the liquid crystal molecules in the common electrode region. As a result, the liquid crystal molecules cause a rotational movement, so that the aperture ratio of the liquid crystal panel is improved by about 30%.

The P-type liquid crystal composition represented by the above formula (LCP-1) is mixed with 98% by weight of the compound represented by the formula (V1-1-1) in an amount of 2.0% by weight, and heated to 60 ° C. to form a liquid crystal assembly. After being dissolved in a substance, it was injected into a liquid crystal cell by a vacuum injection method. The polymerization photoinitiator Irgacure 651 is contained in an amount of 2.0% with respect to the compound represented by the formula (V1-1-1). After injecting the liquid crystal, the injection port was sealed with a sealing agent 3026E (manufactured by ThreeBond Co., Ltd.). Ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) are irradiated at 25 ° C. for 300 seconds to polymerize the polymerizable compound in the polymerizable liquid crystal composition. A liquid crystal display element in FFS mode was manufactured. It was confirmed that when the liquid crystal cells produced between the cross-nicoled polarizing plates were placed in a direction in which the rubbing processing direction and the polarization axis direction coincided with each other, a dark field (normally black) was obtained and uniaxial orientation was obtained. The voltage-response characteristics were measured using the obtained liquid crystal cells. The threshold voltage of 100% by weight of the P-type liquid crystal composition represented by (LCP-1) was 2.5 V, and the saturation voltage was 4.5 V. The light transmittance when a saturation voltage was applied was 70%. On the other hand, when 2.0% by weight of the compound represented by the formula (V1-1-1) was polymerized, the threshold voltage was 2.5V, which was almost the same, but the saturation voltage was 7.1V, which was about 3V saturation voltage. Has risen. The threshold voltage showed almost the same value regardless of the presence or absence of polymer network structure formation by photopolymerization. One reason for this is that the rotation angle of the low-molecular-weight liquid crystal in the voltage drive region near the threshold value is not so large, so that it is not easily affected by obstacles to rotational movement due to the polymer network structure and anchoring force. Moreover, since the dielectric anisotropy of the P-type liquid crystal composition used is as large as 7.5 and the display mode is also FFS, the distance between the common electrode and the pixel electrode is narrower than that in the IPS mode, and the lateral electric field is efficient. It is considered that it is applied to. However, it has been generally confirmed that the threshold voltage tends to increase as the amount of the photopolymerizable monomer added increases.

On the other hand, when a high voltage is applied, the rotation angle of the liquid crystal molecules becomes large, and as a result of the rotational movement being hindered by the polymer network structure and anchoring force, the saturation voltage rises, and the rise width becomes larger than that of the threshold voltage. As a result, the voltage-transmission property will have a slower slope than those that do not form a polymer network.
Next, using the obtained liquid crystal cell, the voltage dependence of the rise response time τr and the fall time τd was measured, respectively. τr (0%) and τd (0%) are the response times of cells using a liquid crystal composition containing no photopolymerizable monomer (V1-1-1), and τr (2%) and τd (2%) are The response time of the liquid crystal cell obtained by polymerizing the liquid crystal composition containing 2% by weight of the photopolymerizable monomer (V1-1-1) is 100% by weight of the P-type liquid crystal composition represented by (LCP-1). When a saturation voltage of 4.5 V was applied to the liquid crystal cell, τr (0%) was 1.0 ms and τd (0%) was 11.4 ms, but 2 weights of monomer (V1-1-1) were added. In the liquid crystal cell using the liquid crystal composition containing%, τr (2%) and τd (2%) when a saturation voltage of 7.1 V was applied were 0.8 ms and 4.7 ms, respectively. Regarding τr, the response time was almost the same regardless of the presence or absence of polymer network formation, but it was confirmed that τd was significantly improved to less than half the time by polymer network formation.
However, it was found that the rising response time near the saturation voltage did not differ significantly even when the polymer network structure was formed.

In this experiment, after confirming that the orientation treatment direction and the polarization axis direction coincide with each other between the cross Nicol state polarizing plates in the state where no voltage is applied, a normal black is obtained, and then a saturation voltage is applied. The liquid crystal cell was observed. An XY stage was installed in a polarizing microscope, and each display region divided into four orientations was observed, but they were optically equivalent and could not be distinguished at all. Even when a voltage intermediate between the threshold and the saturation voltage was applied, the state was completely optically equivalent.
Next, one region out of the four display regions was selected, and the stage of the polarizing microscope was rotated while applying the above-mentioned intermediate voltage to search for the darkest position and fix the angle. In such a state, the other three different regions were observed while moving the XY stage in the X and Y directions. It was observed that the region 180 degrees different from the initially set region had almost the same darkness, and the region 90 degrees different from that had a gray state. As a result, it can be confirmed that the arrangement direction of the liquid crystal molecules is different between the region fixed at least initially and the region different by 90 degrees or 270 degrees, and it can be confirmed that the orientation division is properly performed. It was. These technologies can be adopted not only for moving image display devices such as TVs having high-speed response, but also for field sequential systems that do not require color filters. Further, in recent years, it is expected to be applied to ultra-large high-definition 4K × 2K-TV and 4K × 8K-TV, which are rapidly attracting attention.

1 ... Plate plate, 2 ... First transparent insulating substrate, 3 ... Electrode layer, 4 ... Alignment film, 4a ... Orientation direction, 5 liquid crystal layer, 5a ... Liquid crystal molecules when no voltage is applied, 5b ... Liquid crystal when voltage is applied Molecular, 6 ... color filter, 7 ... second transparent insulating substrate, 8 ... polarizing plate, 9 ... continuous or discontinuous polymer network, 10 ... liquid crystal display element, 11 ... gate electrode, 12 ... gate insulating layer, 13 ... Semiconductor layer, 14 ... protective layer, 15 ... ohmic contact layer, 16 ... drain electrode, 17 ... source electrode, 18 ... insulating protective layer, 21 ... pixel electrode, 22 ... common electrode, 23 ... storage capacitor, 24 ... gate wiring, 25 ... data wiring, 26 ... drain electrode, 27 ... source electrode, 28 ... gate electrode, 29 ... common line, 100 ... polarizing plate, 110 ... gate electrode, 120 ... gate insulating layer, 130 ... semiconductor layer, 140 ... protective layer , 160 ... drain electrode, 190b ... organic insulating film, 200 ... first substrate, 210 ... pixel electrode, 220 ... storage capacitor, 230 ... drain electrode, 240 ... data wiring, 250 ... gate wiring, 260 ... source electrode, 270 ... Gate electrode, 300 ... Thin film layer, 400 ... Alignment film, 500 ... Liquid crystal layer, 510 ... Liquid crystal display device, 512 ... Pixel electrode, 512a ... Pixel stem electrode, 512b ... Pixel branch electrode, 512c ... Pixel slit, 516 ... Scanning wiring, 517 ... Signal wiring, 600 ... Common electrode, 700 ... Color filter, 800 ... Second substrate, 900 ... Plate plate, 1000 ... Liquid crystal display element, 1400 ... Transparent electrode (layer), PX ... Pixel, PE ... Pixel electrode, PA ... Main pixel electrode, PB ... Sub-pixel electrode, CE ... Common electrode, CA ... Main common electrode, CAL ... Left main common electrode, CAR ... Right main common electrode, CB ... Sub-common electrode, CBU ... Upper sub Common electrode, CBB ... Lower sub common electrode

Claims (12)

A polymer or a copolymer is contained in a nematic liquid crystal composition sandwiched between two transparent substrates having electrodes on at least one of them, and the content of the polymer or the copolymer is the liquid crystal composition and the polymer or the copolymer. Obtained by polymerizing one or more of the polymerizable compounds represented by the following general formula (I) in which the polymer or copolymer is 1% by mass or more and less than 40% by mass of the total mass of the coalescence. A liquid crystal display element containing a polymer or copolymer and having a cell structure of VA mode, IPS mode, FFS mode, VA-TN mode, TN mode, and ECB mode.

(In the equation, W ¹ and W ² independently represent single bonds, -O-, -COO- or -OCO-, and Y ¹ and Y ² independently represent -COO- or -OCO-, respectively. , P and q each independently represent an integer of 2 to 13, but the 1,4-phenylene group present in the formula is an alkyl group, an alkoxy group, an alkanoyl group, a cyano group or a halogen having 1 to 7 carbon atoms. It may be substituted with one or more atoms.) The liquid crystal display element according to claim 1, which has a polymer network as a polymer or a copolymer in the liquid crystal composition, and has an alignment layer for orienting the liquid crystal composition on a transparent substrate. The liquid crystal display element according to claim 2, wherein the polymer network has uniaxial refractive index anisotropy, and the optical axis direction or orientation easy axis direction of the polymer network and the orientation easy axis direction of the low molecular weight liquid crystal are the same direction. The liquid crystal display element according to any one of claims 1 to 3, wherein liquid crystal molecules of a low-molecular-weight liquid crystal form a pretilt angle of 0 to 90 ° with respect to a transparent substrate. The liquid crystal display element according to any one of claims 2 to 4, wherein a polymer network layer having a thickness of at least 0.5% or more of the cell thickness is formed in the cell cross-sectional direction. The polymer or copolymer sandwiches a polymerizable compound in a liquid crystal composition sandwiched between two transparent substrates having an electrode on at least one of them, and energy rays while setting the temperature range of the liquid crystal layer to -50 ° C to 30 ° C. The liquid crystal display element according to any one of claims 1 to 5, which is a polymer or copolymer obtained by polymerizing by irradiating with. The polymer or copolymer sandwiches a polymerizable compound in a liquid crystal composition sandwiched between two transparent substrates having electrodes on at least one of them, and has a pretilt angle of 0.1 with respect to the normal direction of the substrate before irradiation with energy rays. The liquid crystal display element according to any one of claims 1 to 6, which is a polymer or a copolymer obtained by polymerizing by irradiating an energy ray while applying a voltage of about 30 degrees. .. The polymer or copolymer is a polymer or copolymer obtained by polymerizing one or more polymerizable compounds selected from the compounds represented by the following general formulas (V) and general formulas (VI). The liquid crystal display element according to any one of claims 1 to 7, which contains a coalescence.

(In the formula, X ¹ and X ² independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² independently represent a single bond, an alkylene group having 1 to 12 carbon atoms or −O−. (CH ₂ ) represents _s − (in the formula, s represents an integer of 1 to 11 and an oxygen atom is bonded to U), where U is a linear or branched multivalent group having 2 to 20 carbon atoms. It represents an alkylene group or a polyvalent cyclic substituent having 5 to 30 carbon atoms, but the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which oxygen atoms are not adjacent to each other, and the number of carbon atoms is 5 to 5. It may be substituted with an alkyl group of 20 (the alkylene group in the group may be substituted with an oxygen atom to the extent that the oxygen atom is not adjacent) or a cyclic substituent, and k represents an integer of 1 to 5. In all 1,4-phenylene groups in the formula, any hydrogen atom may be substituted with -CH ₃ , -OCH ₃ , fluorine atom, or cyano group. However, it is represented by the general formula (I). Excludes polymerizable compounds that are used.)

(In the formula, X ³ represents a hydrogen atom or a methyl group, Sp ³ is a single bond, an alkylene group having 1 to 12 carbon atoms or −O− (CH ₂ ) _t − (in the formula, t is 2 to 2). It represents an integer of 11, and the oxygen atom is bound to V.), where V is a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic substitution having 5 to 30 carbon atoms. Although it represents a group, the alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which oxygen atoms are not adjacent to each other, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group has an oxygen atom). It may be substituted with an oxygen atom in a non-adjacent range) or with a cyclic substituent, and W represents a hydrogen atom, a halogen atom or an alkyl having 1 to 15 carbon atoms. All in the formula. In the 1,4-phenylene group of, any hydrogen atom may be substituted with -CH ₃ , -OCH ₃ , a fluorine atom, or a cyano group. However, a polymerizable compound represented by the general formula (X1b). except for.) The liquid crystal display device according to any one of claims 1 to 8 , wherein the liquid crystal composition contains a liquid crystal compound represented by the following general formula (LC).

(In the general formula ^{(LC), R LC} is one or two or more CH ₂ groups in. The alkyl group represents an alkyl group having 1 to 15 carbon atoms, as the oxygen atoms are not directly adjacent, It may be substituted with −O−, −CH = CH−, −CO−, −OCO−, −COO− or −C≡C−, and one or more hydrogen atoms in the alkyl group are optionally It may be substituted with a halogen atom. A ^LC1 and A ^LC2 each independently represent a group selected from the group consisting of the following groups (a), groups (b) and groups (c).
(A) Trans-1,4-cyclohexylene group (one CH ₂ group existing in this group or two or more CH _two groups not adjacent to each other may be substituted with an oxygen atom or a sulfur atom. .),
(B) 1,4-phenylene group (one CH group existing in this group or two or more CH groups not adjacent to each other may be substituted with a nitrogen atom),
(C) 1,4-bicyclo (2.2.2) octylene group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, 1,2,3,4-tetrahydronaphthalene-2 , 6-Diyl group, or Chroman-2,6-Diyl group.
Even if one or more hydrogen atoms contained in the group (a), group (b) or group (c) are substituted with a fluorine atom, a chlorine atom, -CF ₃ or -OCF ₃ , respectively. Good.
Z ^LC is a single bond, -CH = CH -, - CF = CF -, - C≡C -, - CH 2 CH 2 -, - (CH 2) 4 -, - OCH 2 -, - CH 2 O-, Represents −OCF _2- , −CF ₂ O−, −COO− or −OCO−.
Y ^LC represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group, and an alkyl group having 1 to 15 carbon atoms. One or more CH ₂ groups in the alkyl group are -O-, -CH = CH-, -CO-, -OCO-, -COO-, -C so that oxygen atoms are not directly adjacent to each other. _{≡C -, - CF 2 O -} , - OCF 2 - may be substituted with, one or more hydrogen atoms in the alkyl group may be optionally substituted by a halogen atom.
a represents an integer of 1 to 4. When a represents 2, 3 or 4, and there are a plurality of A ^LC1s in the general formula (LC), the plurality of A ^LC1s may be the same or different, and when a plurality of Z ^LCs are present. , A plurality of Z ^LCs may be the same or different. ) The present invention according to any one of claims 6 to 9, wherein a polymer network having refractive index anisotropy or easy axial direction was formed by using a polymerizable liquid crystal composition containing 1% by mass or more and less than 10% by mass of a polymerizable compound. The liquid crystal display element described. The present invention according to any one of claims 6 to 9, wherein a polymer network having refractive index anisotropy or easy axial direction was formed by using a polymerizable liquid crystal composition containing a polymerizable compound of 10% by mass or more and less than 40% by mass. The liquid crystal display element described. The polymerizable liquid crystal composition according to any one of claims 1 to 11.

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