JP2017037227A - Liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display that is excellent in high-speed responsiveness.SOLUTION: A liquid crystal display contains a polymer or a copolymer being a cured product of a polymerizable composition that contains one or two or more polymerizable compounds and a chiral compound, in a liquid crystal composition that contains one or two or more liquid crystal compounds held between two transparent substrates at least one of which has an electrode; the content of the polymerizable composition in the total weight of the polymerizable composition, chiral compound, and liquid crystal composition is 1 mass% or more and less than 40 mass%.SELECTED DRAWING: Figure 1

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 the use of a backlight that is lit in order of “red → green → blue”. In a normal CRT or liquid crystal display, the frame time is 16.7 ms, but in the field sequential full color display system, the frame time is 5.6 ms, and high-speed response is required.

  As an index indicating high-speed response, the sum of τd and τr can be given. τd is the fall response time of the liquid crystal, and τr is the rise 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, a liquid crystal material called a nematic liquid crystal in the market is generally used in flat panel displays such as televisions, monitors, mobile phones, smartphones, and tablet terminals. However, nematic liquid crystals have a response speed as low as about several tens of milliseconds to several milliseconds, and hence improvement is desired. Since the response speed is greatly influenced by the rotational viscosity γ1 of the liquid crystal and the elastic constant, improvement has been studied by developing new compounds 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 can respond at a high speed of several hundred microseconds. However, since there are only two states of light and dark, it is not easy to display halftones necessary for full color display, and a technique such as area gradation is used.

  Polymer Stabilized V-shaped-FLC (PSV-FLC) element, which is composed of a mixture of FLC and monomer, forms a fine polymer network in ferroelectric liquid crystal, and is a high-speed response characteristic of FLC. In addition to the above, halftone display is possible, and the impact resistance is improved as compared with the conventional FLC (see, for example, Patent Document 1).

  In addition, in a composite material of nematic liquid crystal and polymer, a high-speed response of several tens of microseconds is obtained when 70% by mass or more of a polymerizable compound is added to the nematic liquid crystal medium, 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 polymerizable compounds of 0.3% by mass or more and less than 1% by mass are added to the liquid crystal medium and polymerized on the glass substrate interface by UV photopolymerization with or without application of voltage. A PS (polymer-stable) or PSA (polymer-stained alignment) display that mainly induces pretilt by forming fine protrusion structures obtained by cross-linking has been proposed. (For example, refer to Patent Documents 2 to 6.) However, these devices also have room for improvement in terms of high-speed response. In particular, with regard to increasing the response 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 improved drive method such as an overdrive method. Various methods have been put into practical use, but regarding the falling rate, no effective method has been found other than lowering the viscosity of the liquid crystal composition, and improvement has been desired.

  Further, in the case of a vertical alignment mode MVA type liquid crystal display device with alignment division provided with a protrusion structure or a slit electrode structure, the pretilt angle of liquid crystal molecules relative to the substrate interface is 0.5 with respect to the normal direction of the substrate. When the liquid crystal molecules are aligned in the direction perpendicular to the electric field by applying a high voltage, the liquid crystal molecules are aligned in a random direction in a random direction. Therefore, a phenomenon in which the transmittance increases in two steps as the applied voltage rises due to the phenomenon of light scattering due to the mismatch of the alignment direction of domains between liquid crystal molecules and the rearrangement of liquid crystal domains. Sometimes appears. As a result, there was a problem that the rising response speed was observed extremely slow. In a VA-TN type liquid crystal display device using a liquid crystal composition having negative dielectric anisotropy subjected to alignment division and having no protrusion structure or slit structure devised to solve this type of problem However, when the twist directions of the liquid crystal molecules in the sub-pixel region are different due to the alignment division, there is a problem that the alignment of the liquid crystal molecules is disturbed near the boundary of each sub-pixel region and the display quality is impaired. Further, the TN liquid crystal display device subjected to orientation division having positive dielectric anisotropy has the same problem as described above. In addition, an HTN-type (Hybrid Twisted Nematic) liquid crystal having a structure in which one substrate is subjected to a parallel alignment process and the other substrate is subjected to a vertical alignment process and a twist of 90 ° is further applied. A display device has also been devised, and an improvement in performance can be expected in terms of faster response and lower threshold voltage compared to a conventional TN liquid crystal display device. Had similar problems.

JP 2002-31821 A Special table 2013-536271 gazette Special table 2013-538249 gazette Special table 2012-527495 gazette Special table 2012-513482 gazette JP 2012-219270 A

  The problem to be solved by the present invention is to improve the fall time of the liquid crystal while suppressing the increase of the driving voltage, suppressing the reduction of the birefringence and improving the transmittance, thereby improving the transmittance and the high speed response. It is an object to provide a liquid crystal display device that has excellent performance and improved viewing angle characteristics.

  The present inventor forms a polymer network having a refractive index anisotropy and an alignment function in the entire liquid crystal cell in a liquid crystal composition and a polymerizable liquid crystal composition containing a polymerizable compound, and achieves a high-speed response. Focusing on the use of chiral compounds for the purpose of improving oblique viewing angle characteristics, the optimum content of polymerizable compounds, the alignment of the alignment direction of the liquid crystal by the alignment film and the consistency of the formation direction of the polymer network, It came to be completed.

  As a means for enlarging the oblique viewing angle, in a liquid crystal display device having a twisted liquid crystal molecular arrangement such as TN type, HTN type, and VA-TN type, a mask rubbing method or a photo-alignment method is used. The liquid crystal molecular alignment may be horizontal or vertical alignment having a different twist angle or twist direction for each sub-pixel, or hybrid alignment. In the case of alignment division using the mask rubbing method, the rubbing direction of the upper and lower substrates is taken into consideration, and the horizontal alignment is performed by rubbing in the direction in which the liquid crystal molecule alignment is twisted by approximately 90 ° between the upper and lower substrates for each subpixel. In the case of orientation, a slight pretilt angle is given in a desired direction with respect to the parallel direction of the substrate, and in the case of vertical orientation with respect to the normal direction of the substrate, so that the twist direction can be made uniform. On the other hand, when the photo-alignment method is used, an arbitrary pretilt can be given to the vertical alignment photo-alignment film with respect to the normal direction of the substrate, but in the case of a horizontal photo-alignment film, the direction parallel to the substrate The pretilt angle given to is approximately 0 °, and the twist direction is often not determined. Therefore, in either the mask rubbing method or the photo-alignment method using a photomask, it is necessary to add a chiral compound in order to stably align the twist direction in a desired direction. When using the mask rubbing method, the pretilt angle given during rubbing is used to align the liquid crystal alignment direction of each sub-pixel with the polymer network formation direction and eliminate the reverse domain in the alignment direction between the liquid crystal molecule domains. By adding a chiral compound having the same rotational direction as the twisting direction caused by, and when using the photo-alignment method using a photomask, the rotational direction does not matter, but the chiral direction has a constant rotational direction. By adding a compound, the inventors have solved the problems of the background art.

  [1] Polymerization containing one or more polymerizable compounds in a liquid crystal composition containing one or more liquid crystal compounds sandwiched between two transparent substrates having electrodes on at least one side A polymer or copolymer, which is a cured product of the polymerizable composition, and a chiral compound, wherein the polymerizable composition, the chiral compound, and the content of the polymerizable composition in the total weight of the liquid crystal composition are 1 mass. % Or less and less than 40% by mass of a liquid crystal display element.

  [2] The liquid crystal display device according to [1], wherein the polymer or copolymer in the liquid crystal composition forms a polymer network and has an alignment layer for aligning 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 axis direction of the polymer network and the easy-orientation axis direction of the liquid crystal composition are the same direction. Liquid crystal display element.

  [4] The liquid crystal display element according to any one of [1] to [3], wherein the liquid crystal composition forms a pretilt angle of 0 to 90 ° with respect to a normal direction of the transparent substrate.

  [5] The liquid crystal display element according to any one of [2] to [4], wherein a polymer network layer having a thickness of 0.5% or more of the cell thickness is formed in the cell cross-sectional direction.

  [6] The above [2] to [5], wherein the optical axis direction or the easy axis direction of the polymer network forms a pretilt angle of 0.1 to 30.0 ° with respect to the normal direction or horizontal direction of the transparent substrate. Any one liquid crystal display element.

  [7] The liquid crystal display element according to any one of [1] to [6], wherein the polymerizable compound contains one or more compounds selected from compounds represented by the following general formula (P).

(In the formula, Z ^p1 is a fluorine atom, a cyano group, a hydrogen atom, an alkyl group having 1 to 15 carbon atoms in which a hydrogen atom may be substituted with a halogen atom, or a hydrogen atom in which a hydrogen atom is substituted. A good alkoxy group having 1 to 15 carbon atoms, a alkenyl group having 1 to 15 carbon atoms in which a hydrogen atom may be substituted with a halogen atom, and 1 to 1 carbon atoms in which a hydrogen atom may be substituted with a halogen atom 15 alkenyloxy groups or -Sp ^p2 -R ^p2 ,
R ^p1 and R ^p2 are each independently the following formulas (R-I) to (R-IX):

In the formulas (RI) to (R-IX), R ^{2 to} R ⁶ are independently of each other a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the number of carbon atoms. 1 to 5 halogenated alkyl groups, W is a single bond, —O— or a methylene group, T is a single bond or —COO—, p, t and q are each independently 0, Represents 1 or 2,
Sp ^p1 and Sp ^p2 each represent a spacer group, and Sp ^p1 and Sp ^p2 each independently represent a single bond, an alkylene group having 1 to 12 carbon atoms, or —O— (CH ₂ ) _s — (wherein s is L 1 represents an integer of 1 to 11, and an oxygen atom is bonded to an aromatic ring.) L ^p1 and L ^p2 each independently represent a single bond, —O—, —S—, —CH ₂ —, _{-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— (wherein, R ^a each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, wherein z is an integer of 1 to 4) Represents)
M ^p2 represents 1,4-phenylene group, 1,4-cyclohexylene group, anthracene-2,6-diyl group, phenanthrene-2,7-diyl group, pyridine-2,5-diyl group, pyrimidine-2, 5-diyl group, naphthalene-2,6-diyl group, indane-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or 1,3-dioxane-2,5 -Represents a diyl group, but M ^p2 is unsubstituted or an alkyl group having 1 to 12 carbon atoms, a halogenated alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a carbon atom ^May be substituted with a halogenated alkoxy group of formulas 1 to 12, a halogen atom, a cyano group, a nitro group or —R ^p1 ;
M ^p1 represents the following formulas (i-11) to (ix-11):

(In the formula, it binds to Sp ^p1 with ★ and binds to L ^p1 or L ^p2 with ★★),
M ^p3 represents the following formulas (i-13) to (ix-13):

(In the formula, it binds to Z ^p1 with ★ and binds to L ^p2 with ★★),
m ^{p2 to} m ^p4 each independently represents 0, 1, 2 or 3, and m ^p1 and m ^p5 each independently represent 1, 2 or 3, but when a plurality of Z ^p1 are present, May be the same or different. When a plurality of R ^p1 are present, they may be the same or different. When a plurality of R ^p2 are present, they may be the same. They may be different, they may be the same or different when multiple Sp ^p1 are present, and they may be the same or different when multiple Sp ^p2 are present, When a plurality of L ^p1 are present, they may be the same or different, and when a plurality of M ^p2 are present, they may be the same or different. )
[8] The liquid crystal display element according to any one of [1] to [7], which contains a liquid crystal compound represented by the following general formula (LC) as a liquid crystal composition.

(In the general formula (LC), R ^LC represents an alkyl group having 1 to 15 carbon atoms. One or two or more CH ₂ groups in the alkyl group are not directly adjacent to each other. -O-, -CH = CH-, -CO-, -OCO-, -COO- or -C≡C- may be substituted, and one or more hydrogen atoms in the alkyl group may be optionally substituted A ^LC1 and A ^LC2 each independently represents a group selected from the group consisting of the following groups (a), (b) and (c).
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ 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 present in this group or two or more non-adjacent CH groups 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.

One or two or more hydrogen atoms contained in the group (a), group (b) or group (c) may be 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—, —OCF ₂ —, —CF ₂ O—, —COO— or —OCO— is represented.
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 may be —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C, so that the oxygen atom is not directly adjacent. ≡C—, —CF ₂ O—, —OCF ₂ — may be substituted, and one or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.
a represents an integer of 1 to 4. When a represents 2, 3 or 4, and there are a plurality of ^ALC1s in the general formula (LC), the plurality of ^ALC1s may be the same or different, and there are a plurality of ^ZLCs A plurality of Z ^LCs may be the same or different. )
[9] The liquid crystal display element according to any one of [1] to [8], wherein the cell structure is VA-TN type, TN type, or HTN type.

  [10] The liquid crystal alignment azimuth of adjacent subpixels divided in two directions is approximately 180 °, and the liquid crystal alignment azimuth of adjacent subpixels divided in four directions is approximately 90 ° different from each other. [1] Any one liquid crystal display element of [9].

  [11] A liquid crystal composition containing one or more liquid crystal compounds sandwiched between two transparent substrates having an electrode on at least one side, and a polymerizability containing one or more polymerizable compounds A polymer or copolymer that is a cured product of the composition and a chiral compound are contained, and the content of the polymerizable composition in the total weight of the polymerizable composition, the chiral compound, and the liquid crystal composition is 1% by mass. The liquid crystal display element formed by superposing | polymerizing the polymeric compound in the composition which is less than 40 mass% above by irradiating an energy ray.

  [12] The liquid crystal display element according to [11], wherein the polymerizable compound in the composition is polymerized by irradiating energy rays at a temperature of −50 ° C. to 30 ° C.

  [13] While applying a voltage such that the pretilt angle with respect to the normal direction or the horizontal direction of the transparent substrate before irradiation with energy rays is 0.1 to 30.0 °, the polymerizable compound in the composition is irradiated with energy rays. The liquid crystal display element according to the above [11] or [12], which is polymerized by irradiating.

  According to the present invention, the rise in driving voltage is suppressed, the reduction in birefringence is suppressed and the transmittance is improved, and the fall time of the liquid crystal is improved. It is another object of the present invention to provide a liquid crystal display device with improved viewing angle characteristics.

It is a schematic diagram of a polymer network structure and a liquid crystal molecular arrangement of a VA-TN type liquid crystal display element according to the present invention. It is the photograph which observed the orientation polymerization phase separation structure in the cell which applied the voltage to the vertical alignment cell and UV-exposed the liquid crystal in the homogeneous alignment state, and its explanatory drawing. It is a schematic diagram of the liquid crystal display element of this invention. It is the elements on larger scale of [FIG. 3]. It is a schematic diagram of the pixel electrode structure of the VA-TN type liquid crystal display device in the present invention. It is a schematic diagram of the liquid crystal display element of this invention. FIG. 3 is a schematic diagram of right-twisted quadrant alignment by a mask rubbing method of the present invention. It is a schematic diagram which shows the molecular arrangement | sequence of the liquid crystal molecule of the VA-TN liquid crystal cell in this invention. It is the measurement result of the response time by the difference in temperature at the time of superposition | polymerization. It is the measurement result of the voltage-transmittance characteristic by the difference in temperature at the time of superposition | polymerization. It is the measurement result of the response time by the difference in temperature at the time of superposition | polymerization.

<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 may be —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C, so that the oxygen atoms are not directly adjacent. ≡C— may be substituted, 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 group (a), group (b) and group (c).
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ 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 present in this group or two or more non-adjacent CH groups 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.

One or two or more hydrogen atoms contained in the group (a), group (b) or group (c) may be 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 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 may be —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C, so that the oxygen atom is not directly adjacent. ≡C—, —CF ₂ O—, —OCF ₂ — may be substituted, and one or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.

In general formula (LC), a represents an integer of 1 to 4. When a represents 2, 3 or 4, and there are a plurality of ^ALC1s in the general formula (LC), the plurality of ^ALC1s may be the same or different, and there are a plurality of ^ZLCs 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 group of compounds represented by the following general formula (LC1) and general formula (LC2).

In general formula (LC1) or (LC2), R ^LC11 and R ^LC21 each independently represents an alkyl group having 1 to 15 carbon atoms, and one or more CH ₂ groups in the alkyl group are One of the alkyl groups may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atoms are not directly adjacent. Alternatively, two or more hydrogen atoms may be optionally substituted with a halogen atom. As the compound represented by the general formula (LC1) or (LC2), R ^LC11 and R ^LC21 are each independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or the number of 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, and is further linear. The alkenyl group preferably represents the following structure.

(In the formula, it shall be bonded to the ring structure at the right end.)
In general formula (LC1) or (LC2), A ^LC11 and A ^LC21 each independently represent any one of the following structures. In the structure, one or more CH ₂ groups in the cyclohexylene group may be substituted with an oxygen atom, and one or more CH groups in the 1,4-phenylene group are nitrogen atoms. 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), ^ALC11 and ^ALC21 each independently preferably have one 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 each 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 a fluorine atom or —OCF ₃ is More preferred is a fluorine atom.

In general formula (LC1) or (LC2), Z ^LC11 and Z ^LC21 each independently represent 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 —OCO— is represented. As 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— is preferred, and a single bond, —CH ₂ CH ₂ —, —OCH ₂ —, —OCF ₂ — or —CF ₂ O— is more preferred, and a single bond , —OCH ₂ — or —CF ₂ O— is more preferable.

In 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), ^mLC11 and ^mLC21 are preferably independently 1, 2 or 3, respectively, and when importance is attached to storage stability at low temperature and response speed. 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 formula (LC1-a) to general formula (LC1-c). Is preferred.

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 formulas (LC1-a) to (LC1-c), R ^LC11 is independently 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 is preferable, and 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 general formulas (LC1-a) to (LC1-c), A ^LC1a1 , ^ALC1a2 and ^ALC1b1 are trans-1,4-cyclohexylene group, tetrahydropyran-2,5-diyl group, 1,3-dioxane. Represents a -2,5-diyl group. Further, in the general formula (LC1-a) ~ (LC1 -c), X LC1b1, X LC1b2, X LC1c1 ~X LC1c4 are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a -CF ₃ or -OCF ₃ Represent. As a compound represented by general formula (LC1-a) to general formula (LC1-c), ^XLC1b1 , ^XLC1b2 , and ^{XLC1c1 to XLC1c4} are each independently preferably a hydrogen atom or a fluorine atom.

  Moreover, it is also preferable that general formula (LC1) is 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by the following general formula (LC1-d) to 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 is independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or the number of carbon atoms. An alkenyl group having 2 to 7 carbon atoms is preferable, and 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, X LC11} and ^{X LC12} is preferably a hydrogen atom or a fluorine atom independently. Y ^LC11 is preferably each independently a fluorine atom, —CF ₃ or —OCF ₃ .

In general formulas (LC1-d) to (LC1-p), ^ALC1d1 , ^ALC1f1 , ^ALC1g1 , ^ALC1j1 , ^ALC1k1 , ^ALC1k2 , ^{ALC1m1 to ALC1m3} are each independently a 1,4-phenylene group , 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 , ^XLC1k1 , ^XLC1k2 , ^XLC1m1 and ^XLC1m2 each independently represent a hydrogen atom, a chlorine atom, a 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 each independently preferably a hydrogen atom or a fluorine atom.

In the general formulas (LC1-d) to (LC1-p), Z ^LC1d1 , Z ^LC1e1 , Z ^LC1j1 , Z ^LC1k1 , Z ^LC1m1 are each independently 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 —OCO— Represent. As the compounds represented by the general formulas (LC1-d) to (LC1-p), ^{ZLC1d1 to ZLC1m1} are each independently a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —CF ₂ O— or —OCH ₂ — is preferred.

As the compounds represented by the general formulas (LC1-d) to (LC1-p), one selected from the group consisting of compounds represented by the following general formulas (LC1-1) to (LC1-45) or Two or more compounds are preferred. In general formula (LC1-1) to 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 formula (LC2-a) to general formula (LC2-g).

In the general formulas (LC2-a) to (LC2-g), R ^LC21 , Y ^LC21 , X ^{LC21 to} X ^LC23 are each independently R ^LC21 , Y ^LC21 , 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 is independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or the number of carbon atoms. An alkenyl group having 2 to 7 carbon atoms is preferable, and 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. X ^{LC21 to} X ^LC23 are each independently preferably a hydrogen atom or a fluorine atom, and Y ^LC21 is independently preferably a fluorine atom, —CF ₃ or —OCF ₃ .

In general formulas (LC2-a) to (LC2-g), ^{XLC2d1 to XLC2d4} , ^{XLC2e1 to XLC2e4} , ^{XLC2f1 to XLC2f4} and ^{XLC2g1 to XLC2g4} are each independently a hydrogen atom, chlorine atom, fluorine 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 each independently preferably a hydrogen atom or a fluorine atom.

In general formulas (LC2-a) to (LC2-g), Z ^LC2a1 , Z ^LC2b1 , Z ^LC2c1 , Z ^LC2d1 , Z ^LC2e1 , Z ^LC2f1 and Z ^LC2g1 are each independently 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 -OCO- is represented. Examples of the compound represented by the general formula (LC2-a) ~ (LC2 -g), Z LC2a1 ~Z LC2g4 each independently _-CF 2 O-or -OCH ₂ - is preferred.

  The compound represented by the general formula (LC) is also preferably one or two or more compounds selected from the group of compounds represented by the following general formula (LC3) to general formula (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 — may be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C≡C— so that the oxygen atom is not directly adjacent. 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 is Any one of which 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 ). 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—, Z ⁵ represents —CH ₂ — or an oxygen atom, and X ^LC41 represents ^Represents a hydrogen atom or a fluorine atom, m ^LC31 , m ^{L C32, m LC41, m LC42,} m LC51 and ^{m LC52} represent each independently ^{0~3, m LC31 + m LC32,} m LC41 + m LC42 and ^m LC51 ^{+ m LC52} is 1, 2 or ^{3, A LC31} ~ When a plurality of A ^LC52 and Z ^{LC31 to} Z ^LC52 are present, they may be the same or different. )
It is preferable that 1 type, or 2 or more types of compounds chosen from the group which consists of a compound represented by these are included.

R ^{LC31 to} R ^LC52 are each independently preferably an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms. Most preferably,

(In the formula, it shall be bonded to the ring structure at the right end.)
A ^{LC31 to} A ^LC52 each independently preferably have the following structure:

Z ^{LC31 to} Z ^LC51 are each independently a single bond, —CH ₂ O—, —COO—, ^—OCO— , —CH ₂ CH ₂ —, —CF ₂ O—, —OCF ₂ — or —OCH ₂ —. preferable.

  As a compound represented by General Formula (LC3), General Formula (LC4), and General Formula (LC5), General Formula (LC3-1), General Formula (LC4-1), and General Formula (LC5-1)

Wherein R ^{31 to} R ³³ are alkyl groups having 1 to 8 carbon atoms, alkenyl groups having 2 to 8 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, or alkenyloxy groups 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. Z ^{31 to} Z ³³ are 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, and Z ³⁴ represents —CH ₂ — or an oxygen atom. It is preferable to contain at least one compound selected from the group .

In General Formula (LC3-1) to General Formula (LC5-1), R ^{31 to} R ³³ are each an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. Represents an alkoxy group or an alkenyloxy group having 2 to 8 carbon atoms, preferably 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 More preferably, it represents a group or an alkenyl group having 2 to 4 carbon atoms, more preferably 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 preferred 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. More preferably, it represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, more preferably represents an alkyl group having 3 carbon atoms or an alkoxy group having 2 carbon atoms, and has 2 carbon atoms. It is particularly preferred to represent an alkoxy group.

Z ^{31 to} Z ³³ are 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— represents a single bond, —CH ₂ CH ₂ —, —COO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or — It preferably represents CF ₂ O—, and more preferably represents 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 group of compounds represented by General Formula (LC3-1), General Formula (LC4-1), and General Formula (LC5-1). It is preferable to contain 5% to 40% by weight, more preferably 5% to 30% by weight, more preferably 8% to 27% by weight, and more preferably 10% to 25% by weight. % Content is more preferable.

  Specifically, the compound represented by the general formula (LC3-1) is preferably a compound represented by the following general formula (LC3-11) to general formula (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 formula (LC4-11) to general formula (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 Represents a fluorine atom.)
Specifically, the compound represented by the general formula (LC5-1) is preferably a compound represented by the following general formula (LC5-11) to general formula (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 general formula (LC3-11), general formula (LC3-13), general formula (LC4-11), general formula (LC4-13), general formula (LC5-11), and general formula (LC5-13), R ^{31 to} R ³³ are preferably the same embodiments in general formula (LC3-1) to general formula (LC5-1). 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 general formula (LC3-12), general formula (LC3-14), general formula (LC4-12), general formula (LC4-14), general formula (LC5-12), and general formula (LC5-14), R ^{31 to} R ³³ are preferably the same embodiments in general formula (LC3-1) to general formula (LC5-1). 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 general formulas (LC3-11) to (LC5-14), in order to increase the absolute value of dielectric anisotropy, general formula (LC3-11), general formula (LC4-11), Formula (LC5-11), general formula (LC3-13), general formula (LC4-13) and general formula (LC5-13) are preferred, and general formula (LC3-11), general formula (LC4-11), general formula Formula (LC5-11) is more preferred.

  The liquid crystal layer in the liquid crystal display element of the present invention preferably contains one or more compounds represented by general formulas (LC3-11) to (LC5-14), and contains one or two kinds. It is more preferable to contain 1 type or 2 types of compounds represented by general formula (LC3-1).

  Moreover, as a compound represented by general formula (LC3), general formula (LC4), and general formula (LC5), general formula (LC3-2), general formula (LC4-2), and general formula (LC5-2) )

Wherein 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 each} represents a 1,4-phenylene group or a trans-1,4-cyclohexylene group which may be fluorine-substituted, Z ^{41 to} Z ⁴³ are 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- the ^{stands, X 42} represents a hydrogen atom or a fluorine atom, ^{Z 4} It is -CH ₂ - represents an or an oxygen atom).
It is preferable to contain at least one compound selected from the group of compounds represented by:

In General Formula (LC3-2), General Formula (LC4-2), and General Formula (LC5-2), R ^{51 to} R ⁵³ are each an alkyl group having 1 to 8 carbon atoms, and an alkenyl having 2 to 8 carbon atoms. Group, an alkoxy group having 1 to 8 carbon atoms or an alkenyloxy group having 2 to 8 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms. More preferably, it represents an alkyl group having 2 to 5 carbon atoms or an alkenyl group having 2 to 4 carbon atoms, and more preferably represents an alkyl group having 3 to 5 carbon atoms or an alkenyl group having 2 carbon atoms. And particularly preferably 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. More preferably, it represents an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms, more preferably represents an alkyl group having 3 carbon atoms or an alkoxy group having 2 carbon atoms, and has 2 carbon atoms. It is particularly preferred to represent an alkoxy group.

B ^{31 to} B ³³ each represents 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- A cyclohexylene group is preferred, and a trans-1,4-cyclohexylene group is more preferred.

Z ^{41 to} Z ⁴³ are 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— represents a single bond, —CH ₂ CH ₂ —, —COO—, —OCH ₂ —, —CH ₂ O—, —OCF ₂ — or — It preferably represents CF ₂ O—, and more preferably represents a single bond or —CH ₂ O—.

  The compound represented by general formula (LC3-2), general formula (LC3-3), general formula (LC4-2), and general formula (LC5-2) is contained in an amount of 10 to 60% by mass in the liquid crystal composition. However, it is more preferable to contain 20 to 50% by mass, more preferably 25 to 45% by mass, more preferably 28 to 42% by mass, and more preferably 30 to 40% by mass. Further preferred.

  Specifically, the compound represented by the general formula (LC3-2) is preferably a compound represented by the following general formula (LC3-21) to general formula (LC3-29).

  Moreover, as a compound represented by general formula (LC3-3), the compound represented by the following general formula (LC3-31)-general formula (LC3-33) is 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. Preferred is the same embodiment as R ⁵¹ and R ⁶¹ in 2).
Specifically, the compound represented by the general formula (LC4-2) is preferably a compound represented by the following general formula (LC4-21) to general formula (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 (It represents a fluorine atom, but an embodiment similar to R ⁵² and R ⁶² in formula (LC4-2) is preferred.)
Specifically, the compound represented by the general formula (LC5-2) is preferably a compound represented by the following general formula (LC5-21) to general formula (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. -Represents an oxygen atom, but an embodiment similar to R ⁵³ and R ⁶³ in formula (LC5-2) is preferred.)
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 represent general formula (LC3-2), general formula (LC4-2), and general formula ( Similar embodiments in LC5-2) are 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 represent general formula (LC3-2), general formula (LC4-2), and general formula (LC5- Similar embodiments in 2) are 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 general formulas (LC3-21) to (LC5-26), in order to increase the absolute value of dielectric anisotropy, general formula (LC3-21), general formula (Lc3-22) and general formula Formula (LC3-25), Formula (LC4-21), Formula (LC4-22) and Formula (LC4-25), Formula (LC5-21), Formula (LC5-22) and Formula ( 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 be contained alone or in combination of two or more, but B ^{1 to} B ³ are 1, It is preferable to contain at least one compound each representing a 4-phenylene group and a compound in which B ^{1 to} B ³ represent a trans-1,4-cyclohexylene group.

  Other examples of the compound represented by the general formula (LC3) include the following general formula (LC3-a) and general formula (LC3-b).

(Wherein R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 each independently represent the same meaning as R ^LC31 , R ^LC32 , A ^LC31 and Z ^LC31 in the general formula (LC3), and X ^{LC3b1 to} X ^LC3b6 are Represents a hydrogen atom or a fluorine atom, and at least one of X ^LC3b1 and X ^LC3b2 or X ^LC3b3 and X ^LC3b4 represents a fluorine atom, m ^LC3a1 is 1, 2 or 3, and 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.) Or one or more compounds selected from the group of compounds represented by Is preferred.

R ^LC31 and R ^LC32 are each independently 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. Is preferably represented.

A ^LC31 preferably represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group, a tetrahydropyran-2,5-diyl group, or a 1,3-dioxane-2,5-diyl group. , 4-phenylene group and trans-1,4-cyclohexylene group are 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 general formula (LC3-a), it is preferable to represent the following general formula (LC3-a1).

(In the formula, R ^LC31 and R ^LC32 each independently represent the same meaning as R ^LC31 and R ^LC32 in 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, or an alkenyl group having 2 to 7 carbon atoms, and R ^LC31 has 1 carbon atom. It is more preferable that R 7 represents an alkyl group having ^˜7 , and R ^LC32 represents an alkoxy group having 1 to 7 carbon atoms.

  As general formula (LC3-b), it is preferable to represent the following general formula (LC3-b1) to general formula (LC3-b12), and general formula (LC3-b1), general formula (LC3-b6), and general formula (LC3-b8) and general formula (LC3-b11) are more preferable, general formula (LC3-b1) and general formula (LC3-b6) are more preferable, and general formula (LC3-b1) is represented. Most preferably it represents.

(In the formula, R ^LC31 and R ^LC32 each independently represent the same meaning as R ^LC31 and R ^LC32 in 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, or an alkenyl group having 2 to 7 carbon atoms, and R ^LC31 has 2 carbon atoms. Or an alkyl group having 3 carbon atoms, and more preferably R ^LC32 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 general formula (LC4-c), and the compound represented by the general formula (LC5) is: Compounds represented by the following general formula (LC5-a) to general formula (LC5-c) are preferred.

^{(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 It 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 -7 alkenyloxy groups.

Z ^{LC4a1 to} Z ^LC5c1 each independently preferably represents a single bond, —CH ₂ O—, ^{—COO—, —OCO—} , —CH ₂ CH ₂ —, and more preferably represents 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 formula (LC1) to the general formula (LC5)). It is also preferable that it is 1 type, or 2 or more types of compounds.

In 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 may be —O—, —CH═CH—, —CO—, —OCO—, —COO— or —C, so that the oxygen atoms are not directly adjacent. ≡C— may be substituted, 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 are each independently an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or 2 to 7 carbon atoms. The alkenyl group is preferably represented by any one of the following structures.

(In the formula, it shall be bonded to the ring structure at the right end.)
In General Formula (LC6), A ^{LC61 to} A ^LC63 each 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 —. One or two 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 has one of the following structures.

In the general formula (LC6), 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. As the compound represented by the general formula (LC6), Z ^LC61 and Z ^LC62 are each independently a single bond, —CH ₂ CH ₂ —, ^—COO— , —OCH ₂ —, —CH ₂ O—, —OCF _2. - or _-CF 2 O-are preferred.

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

[Polymerizable compound]
Examples of the polymerizable compound according to the present invention 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. Can be mentioned. 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 by light. In particular, when the vertical alignment film is formed by thermal polymerization, the reaction of the polymerizable compound having a reactive group can be suppressed during the thermal polymerization of the vertical alignment film material. Substituents are particularly preferred.

  As the polymerizable compound according to the present invention, the following general formula (P)

(In the general formula (P), Z ^p1 represents a fluorine atom, a cyano group, a hydrogen atom, an alkyl group having 1 to 15 carbon atoms in which the hydrogen atom may be substituted with a halogen atom, and a hydrogen atom in the halogen atom. An optionally substituted alkoxy group having 1 to 15 carbon atoms, a hydrogen atom in which a hydrogen atom may be substituted with a halogen atom, and a hydrogen atom in which a hydrogen atom may be substituted with a halogen atom Represents an alkenyloxy group having 1 to 15 carbon atoms or -Sp ^p2 -R ^p2 ;
R ^p1 and R ^p2 are each independently the following formulas (R-I) to (R-IX):

In the formulas (RI) to (R-IX), R ^{2 to} R ⁶ are independently of each other a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the number of carbon atoms. 1 to 5 halogenated alkyl groups, W is a single bond, —O— or a methylene group, T is a single bond or —COO—, p, t and q are each independently 0, Represents 1 or 2,
Sp ^p1 and Sp ^p2 each represent a spacer group, and Sp ^p1 and Sp ^p2 each independently represent a single bond, an alkylene group having 1 to 12 carbon atoms, or —O— (CH ₂ ) _s — (wherein s is L 1 represents an integer of 1 to 11, and an oxygen atom is bonded to an aromatic ring.) L ^p1 and L ^p2 each independently represent a single bond, —O—, —S—, —CH ₂ —, _{-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— (wherein, R ^a each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, wherein z is an integer of 1 to 4) Represents)
M ^p2 represents 1,4-phenylene group, 1,4-cyclohexylene group, anthracene-2,6-diyl group, phenanthrene-2,7-diyl group, pyridine-2,5-diyl group, pyrimidine-2, 5-diyl group, naphthalene-2,6-diyl group, indane-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or 1,3-dioxane-2,5 -Represents a diyl group, but M ^p2 is unsubstituted or an alkyl group having 1 to 12 carbon atoms, a halogenated alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a carbon atom ^May be substituted with a halogenated alkoxy group of formula 1 to 12, a halogen atom, a cyano group, a nitro group or —R ^p1 ;
M ^p1 represents the following formulas (i-11) to (ix-11):

(In the formula, it binds to Sp ^p1 with ★ and binds to L ^p1 or L ^p2 with ★★),
M ^p3 represents the following formulas (i-13) to (ix-13):

(In the formula, it binds to Z ^p1 with ★ and binds to L ^p2 with ★★),
m ^{p2 to} m ^p4 each independently represents 0, 1, 2 or 3, and m ^p1 and m ^p5 each independently represent 1, 2 or 3, but when a plurality of Z ^p1 are present, May be the same or different. When a plurality of R ^p1 are present, they may be the same or different. When a plurality of R ^p2 are present, they may be the same. They may be different, they may be the same or different when multiple Sp ^p1 are present, and they may be the same or different when multiple Sp ^p2 are present, When a plurality of L ^p1 are present, they may be the same or different, and when a plurality of M ^p2 are present, they may be the same or different. It is preferably represented by a compound represented by Moreover, it is preferable to contain the said polymeric compound 1 type (s) or 2 or more types.

In the general formula (P) according to the present invention, Z ^p1 is preferably -Sp ^p2 -R ^p2 , and R ¹¹ and R ¹² are each independently represented by the formulas (R-1) to (R-3). Either is preferable.

In the general formula (P), m ^p1 + m ^p5 is preferably 2 or more.

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—, and L ^p2 represents —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 is COO-, z in the above formula is preferably an integer of 1 to 4.

In addition, at least one of L ^p1 and L ^{p2 in} the general formula (P) is — (CH ₂ ) _z —C (═O) —O— or — (CH ₂ ) z—O— (C═O). - and _{-O- (C = O) - (} CH 2) z -, - (C = O) -O- (CH 2) is preferably at least one selected from the group consisting of z-.

In the general formula (P), R ^p1 and R ^p2 are each independently the following formulas (R-1) to (R-15):

Any of these is more preferable.

In the general formula (P), m ^p3 represents 0, 1, 2, or 3. When m ^p2 is 1, L ^p1 is a single bond, and when m ^p2 is 2 or 3, a plurality of L ^p1 is present. At least one is preferably a single bond.

In the general formula (P), m ^p3 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, a plurality of m ^p3 are present. ^{M p2} adjacent to ^{M p1} through at least ^{L p1} of ^{M p2} which is preferably a 1,4-phenylene group.

Further, m ^{p3 in the} general formula (P) represents 0, 1, 2, or 3, and at least one of M ^p2 is a 1,4-phenylene group substituted with one or two or more fluorines. It is preferable.

Further, m ^{p4 in 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 two or more fluorines. It is preferable.

Further, as the general formula (P) in the spacer group ^{(Sp p1, Sp p2, Sp} p4), 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- is preferred, and Z is an integer of 1-10. Rukoto is preferable.

  The polymerizable compound of the general formula (P) according to the present invention is represented by the general formula (Pa), the general formula (Pb), the general formula (Pc), and the general formula (Pd). It is preferably at least one compound selected from the group consisting of compounds.

In the above general formulas (Pa) to (Pd), R ^p1 and R ^p2 are each independently the following formulas (RI) to (R-IX):

In the formulas (RI) to (R-IX), R ^{2 to} R ⁶ are independently of each other a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the number of carbon atoms. 1 to 5 halogenated alkyl groups, W is a single bond, —O— or a methylene group, T is a single bond or —COO—, p, t and q are each independently 0, Represents 1 or 2,
Ring A and Ring B are each independently 1,4-phenylene group, 1,4-cyclohexylene group, anthracene-2,6-diyl group, phenanthrene-2,7-diyl group, pyridine-2,5- Diyl group, pyrimidine-2,5-diyl group, naphthalene-2,6-diyl group, indane-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or 1, A 3-dioxane-2,5-diyl group, which is unsubstituted or an alkyl group having 1 to 12 carbon atoms, a halogenated alkyl group having 1 to 12 carbon atoms, or an alkoxy having 1 to 12 carbon atoms group, halogenated alkoxy group having 1 to 12 carbon atoms, a halogen atom, a cyano group, that is substituted with a nitro group or a -R ^p1 preferably,
Ring C represents the following formulas (ci) to (c-ix):

(In the formula, it binds to Sp ^p1 with ★ and binds to L ^p5 or L ^p6 with ★★),
Sp ^p1 and Sp ^p4 each represent a spacer group, and X ^{p1 to} X ^p4 preferably each independently represent a hydrogen atom or a halogen atom,
L ^p4 , L ^p5 and L ^p6 are each independently 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 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 ( ^Pa ), it is preferable that m ^p6 and m ^p7 each independently represent 0, 1, 2, or 3. Moreover, it is more preferable that it is ^mp6 + ^mp7 = 2-5.

In the compound represented by the general formula (Pd), ^mp12 and ^mp15 each independently represent 1, 2 or 3, and ^mp13 preferably represents 0, 1, 2 or 3, m ^p14 preferably represents 0 or 1. Moreover, it is more preferable that it is ^mp12 + ^mp15 = 2-5. When a plurality of R ^p1 are present, they may be the same or different. When a plurality of R ^p1 are present, they may be the same or different, and a plurality of R ^p2 are present. In some cases, they may be the same or different. When a plurality of Sp ^p1 are present, they may be the same or different. When there are a plurality of Sp ^p4 , they are 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. Or different.

  The preferable structure of the compound represented by general formula (Pa)-general formula (Pd) which concerns on this invention below is illustrated.

  Preferable examples of the compound represented by the general formula (Pa) according to the present invention include polymerizable compounds represented by the following formulas (Pa-1) to (Pa-31).

  Preferred examples of the compound represented by the general formula (Pb) according to the present invention include polymerizable compounds represented by the following formulas (Pb-1) to (Pb-34).

  Preferred examples of the compound represented by the general formula (Pc) according to the present invention include polymerizable compounds represented by the following formulas (Pc-1) to (Pc-52).

  The compound represented by the general formula (Pd) according to the present invention is preferably a compound represented by the following general formula (P-d ').

(In the compound represented by the above general formula (Pd ′), ^mp10 more preferably represents 2 or 3. The other symbols are the same as those in the above general formula (pd), and will be omitted.)
Preferred examples of the compound represented by the general formula (Pd) according to the present invention include polymerizable compounds represented by the following formulas (Pd-1) to (Pd-31).

The “alkyl group having 1 to 15 carbon atoms” according to the present invention is preferably a linear or branched alkyl group, and more preferably a linear alkyl group. In the general formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 15 carbon atoms, and R ¹ and R ² are each independently 1 to 1 carbon atoms. Eight alkyl groups are preferable, and an alkyl group having 1 to 6 carbon atoms is more preferable.

  Examples of the “alkyl group having 1 to 15 carbon atoms” according to the present invention include methyl, ethyl, propyl, butyl, isopropyl, isobutyl, t-butyl, 3-pentyl, and 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 the “alkoxy group having 1 to 15 carbon atoms” according to the present invention is preferably present at a position where at least one oxygen atom in the substituent is directly bonded to the ring structure, and includes a methoxy group, ethoxy group Group, propoxy group (n-propoxy group, i-propoxy group), butoxy group, pentyloxy group, octyloxy group and decyloxy group are more preferable. In addition, in this specification, the example of an alkoxy group is common and is suitably selected from the said illustration according to the number of carbon atoms of each alkoxy group.

  Examples of the “alkenyl group having 2 to 15 carbon atoms” according to the present invention 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. More preferable alkenyl groups according to the present invention include the following formula (i) (vinyl group), formula (ii) (1-propenyl group), formula (iii) (3-butenyl group) and formula (iv) ) (3-pentenyl group):

(In the above formulas (i) to (iv), * represents a binding site to the ring structure.)
However, when the liquid crystal composition of the present invention contains a polymerizable monomer, structures represented by formula (ii) and formula (iv) are preferable, and a structure represented by formula (ii) is more preferable. preferable. In the present specification, examples of the alkenyl group are common and are appropriately selected from the above examples depending on the number of carbon atoms of each alkenyl group.

  Among the polymerizable compounds in the present invention, examples of the polymerizable compound having a monofunctional reactive group that is preferable for increasing the solubility with a low-molecular liquid crystal and suppressing crystallization include the following general formula (VI).

(In the formula, X ³ represents a hydrogen atom or a methyl group, and Sp ³ represents a single bond, an alkylene group having 1 to 12 carbon atoms, or —O— (CH ₂ ) _t — (wherein t is 2 to 2). Represents an integer of 11 and an oxygen atom is bonded to an aromatic ring.), V is a linear or branched polyvalent alkylene group having 2 to 20 carbon atoms or a polyvalent cyclic group having 5 to 30 carbon atoms. An alkylene group in the polyvalent alkylene group may be substituted with an oxygen atom within a range in which the oxygen atom is 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) Or may be substituted with a cyclic substituent, and W represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 15 carbon atoms. All 1,4-phenylene groups of Meaning hydrogen atoms -CH _3, -OCH _3, fluorine atom, or a cyano group may be substituted. The polymerizable compound represented by) are preferred.

In the general formula (VI), X ³ represents a hydrogen atom or a methyl group. However, when importance is attached to the reaction rate, a hydrogen atom is preferred, and when importance is placed on reducing the residual amount of reaction, a methyl group is preferred. preferable.

In the general formula (VI), Sp ³ represents a single bond, an alkylene group having 1 to 12 carbon atoms, or —O— (CH ₂ ) _t — (wherein t represents an integer of 2 to 11, an oxygen atom Represents the bond to the aromatic ring), but the length of the carbon chain affects Tg, so when the polymerizable compound content is less than 10% by weight, it is preferably not too long. A bond or an alkylene group having 1 to 5 carbon atoms is preferable, and when the polymerizable compound content is less than 6% by weight, a single bond or an alkylene group having 1 to 3 carbon atoms is more preferable. When the polymerizable compound content is 10% by weight or more, an alkylene group having 5 to 10 carbon atoms is preferable. Also, Sp ³ is -O- _{(CH 2) t} - may represent a, t is preferably 1 to 5, 1 to 3 is more preferable. 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 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 an alkylene group in the polyvalent alkylene group. May be substituted with an oxygen atom in a range where the oxygen atoms are not adjacent to each other, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group may be substituted with an oxygen atom within a range where the oxygen atoms are not adjacent to each other) .) Or may be substituted with a cyclic substituent, and is preferably substituted with two or more cyclic substituents.

  More specifically, the polymerizable compound represented by the general formula (VI) is represented by 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 each independently an oxygen atom, assuming that oxygen atoms are not directly bonded to each other, -CO-, -COO- or -OCO- may be substituted, and one or more hydrogen atoms in the alkylene group are each independently substituted with a fluorine atom, a methyl group or an ethyl group. May be)
A ³ and A ⁶ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl group do not have oxygen atoms directly bonded to each other) And each independently may be substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkyl group are each independently a halogen atom. Which may be substituted with an atom or an alkyl group having 1 to 17 carbon atoms).
A ⁴ and A ⁷ are each independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl group do not have oxygen atoms directly bonded to each other) And each independently may be substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkyl group are each independently a halogen atom. Which may be substituted with an atom or an alkyl group of 1 to 9 carbon atoms)
p represents 0-10,
B ¹ , B ² and B ³ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms (one or two or more methylene groups in the alkyl group are In addition, the oxygen atoms may be independently substituted with an oxygen atom, —CO—, —COO—, or —OCO— as those in which oxygen atoms are not directly bonded to each other, and one or two or more of the alkyl groups may be substituted. A hydrogen atom may be independently substituted with a halogen atom or a trialkoxysilyl group having 3 to 6 carbon atoms).

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

  The compounds represented by the general formula (II-b) are specifically compounds represented by the following formulas (II-q) to (II-z), (II-aa) to (II-al). It is preferable.

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

  Moreover, as a polymeric compound represented by general formula (VI), general formula (X1b)

(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 each independently

(Where q represents an integer of 1 to 4),
q represents 0 or 1,
Y ¹ and Y ² are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —COO—, —OCO—, —C≡C—, —CH═CH—. _{, -CF = CF -, - (} CH 2) 4 -, - CH 2 CH 2 CH 2 O -, - OCH 2 CH 2 CH 2 -, - CH = CHCH 2 CH 2 - or _-CH 2 _CH 2 _CH = CH—
Y ³ and Y ⁴ are each independently a single bond, an alkylene group having 1 to 12 carbon atoms (one or two or more methylene groups in the alkylene group are such that oxygen atoms are not directly bonded to each other, Each independently may be substituted with an oxygen atom, -CO-, -COO- or -OCO-, and one or more hydrogen atoms in the alkylene group are each independently a fluorine atom or a methyl group. Or may be substituted with an ethyl group).
B ⁸ represents a hydrogen atom, a cyano group, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkylene group having a terminal acryloyl group or methacryloyl group. And a compound represented by

  Illustrative compounds are shown below, but are not limited thereto.

  Furthermore, the polymerizable compound represented by the general formula (VI) specifically includes the general formula (X1c)

(Wherein R ⁷⁰ represents a hydrogen atom or a methyl group, and R ⁷¹ represents a hydrocarbon group having a condensed ring).

  Illustrative compounds are shown below, but are not limited thereto.

  Among the polymerizable compounds in the present invention, the polymerizable compound having a polyfunctional reactive group that is preferable for increasing the solubility with a low-molecular liquid crystal and suppressing crystallization is represented by the following general formula (V).

(In the formula, X ¹ and X ² each independently represent a hydrogen atom or a methyl group, and 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 — (wherein s represents an integer of 1 to 11 and an oxygen atom is bonded to an aromatic ring), and U is a linear or branched chain having 2 to 20 carbon atoms. 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 the oxygen atom is not adjacent to each other. -20 alkyl group (the alkylene group in the group may be substituted with an oxygen atom within the range where the oxygen atom is not adjacent) or a cyclic substituent, and k is an integer of 1-5. All 1,4-phenyle in the formula Groups, any hydrogen atom is -CH _3, -OCH _3, fluorine atom, or may be substituted by a cyano group.) The polymerizable compound represented by are preferred.

In the general formula (V), X ¹ and X ² each independently represent a hydrogen atom or a methyl group. However, when importance is attached to the reaction rate, a hydrogen atom is preferable, and importance is placed on reducing the amount of residual reaction. In this case, a methyl group is preferred.

In the general formula (V), Sp ¹ and Sp ² are each independently a single bond, an alkylene group having 1 to 12 carbon atoms, or —O— (CH ₂ ) _s — (wherein s is 2 to 11). In which the oxygen atom is bonded to an aromatic ring.) The pretilt angle in the liquid crystal display element of the present invention is the number of carbon atoms, the content with liquid crystal, and the alignment film used. It is affected by the type and orientation processing conditions. Therefore, although not necessarily limited, for example, when the pretilt angle is about 5 degrees, the carbon chain is preferably not so long, a single bond or an alkylene group having 1 to 5 carbon atoms is more preferable, and a single bond Alternatively, an alkylene group having 1 to 3 carbon atoms is more preferable. Furthermore, in order to make 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. Also, when Sp ¹ and Sp ² represent -O- (CH ₂ ) _s- , it affects the pretilt angle, so that 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, and more preferably 1 to 3. For the purpose of reducing the pretilt angle, s is preferably 6 to 10. In addition, since at least one of Sp ¹ and Sp ² is a single bond, a molecular asymmetry is exhibited, which is preferable because pretilt is induced.

In addition, a compound in which Sp ¹ and Sp ² are the same in the general formula (V) is also preferable, and it is preferable to use two or more compounds in which Sp ¹ and Sp ² are the same. In this case, it is more preferable to use two or more different Sp ¹ and Sp ² from each other.

  In the 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 an alkylene group in the polyvalent alkylene group. May be substituted with an oxygen atom in a range where the oxygen atoms are not adjacent to each other, and an alkyl group having 5 to 20 carbon atoms (the alkylene group in the group may be substituted with an oxygen atom within a range where the oxygen atoms are not adjacent to each other) ), May be substituted with a cyclic substituent, and is preferably substituted with two or more cyclic substituents.

  In the general formula (V), U specifically preferably represents the following formulas (Va-1) to (Va-13). In order to increase the anchoring force, biphenyl having high linearity is preferable, and it is preferable to represent the formula (Va-1) to the formula (Va-6). Further, the structure representing the formula (Va-11) to the formula (Va-11) is preferable in terms of high solubility with liquid crystal, and is used in combination with the formula (Va-1) to the formula (Va-6). preferable.

(In the formula, both ends are bonded to Sp ¹ or Sp ^2. Z ^p1 and Z ^p2 are each 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 is —CH ₃ , —OCH ₃ , a fluorine atom, or a cyano group In addition, one or more CH ₂ CH ₂ groups in the cyclohexylene group may be substituted with —CH═CH—, —CF ₂ O—, —OCF ₂ —. May be good.)
When U has a ring structure, at least one of Sp ¹ and Sp ² is —O— (CH ₂ ) _s — (wherein s represents an integer of 1 to 7 and an oxygen atom is bonded to an aromatic ring) It is preferable that both represent —O— (CH ₂ ) _s —.

  In the general formula (V), k represents an integer of 1 to 5, but k is preferably a bifunctional compound of 1 or k is a trifunctional compound of 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).

(In the formula, X ¹ and X ² each independently represent a hydrogen atom or a methyl group, and 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 — (wherein s represents an integer of 1 to 7 and an oxygen atom is bonded to an aromatic ring), 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 -, - C _{^{2 -OCO -, - CY 1 =}} CY 2 - (Y 1 and ^{Y 2} each independently represents a hydrogen atom or a fluorine atom.), - C≡C- or a single bond, C represents 1,4 A phenylene group, a trans-1,4-cyclohexylene group or a single bond is represented, and in all 1,4-phenylene groups in the formula, an arbitrary hydrogen atom may be substituted with a fluorine atom.)
In the general formula (Vb), X ¹ and X ² each independently represent a hydrogen atom or a methyl group, both of which are diacrylate derivatives each representing a hydrogen atom, or both are dimethacrylate derivatives having a methyl group. 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, diacrylate derivatives are the fastest, dimethacrylate derivatives are slow, asymmetric compounds are in the middle, and a preferred embodiment can be used depending on the application.

In the 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 —, at least one of which is —O - _(CH 2) is preferably s-, both -O- _(CH 2) aspects representing the s- is more preferable. In this case, s is preferably 1 to 6.

In the general formula (Vb), 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 each independently represent a hydrogen atom or a fluorine atom), -C≡C- or a single bond, -OCH _2- , -CH ₂ O -, - COO -, - OCO -, - CF 2 O -, - OCF 2 -, - C H ₂ CH ₂ —, —CF ₂ CF ₂ — or a single bond is preferable, —COO—, —OCO— or a single bond is more preferable, and a single bond is particularly preferable. In the 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. -A phenylene group or a single bond is preferable. When C represents a ring structure other than a single bond, Z ¹ is preferably a linking group other than a single bond. When C is a single bond, Z ¹ is preferably a single bond.

  As described above, in the general formula (Vb), it is preferable that C represents a single bond and the ring structure is formed of two rings. Specific examples of the polymerizable compound having a ring structure include the following general formula: Compounds represented by (V-1) to (V-6) are preferred, compounds represented by general formulas (V-1) to (V-4) are particularly preferred, and represented by general formula (V-2). Most preferred are the compounds

  In the above general formula (Vb), the compounds represented by the following general formulas (V1-1) to (V1-5) are preferable for enhancing the solubility with the liquid crystal composition, and the general formula (V1-1) ) Is particularly preferred.

  In addition, the general formula (Vb) is preferably used in the case where it is formed of 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 in terms of enhancement. Furthermore, the compounds represented by the general formulas (V-1) to (V-6) having strong anchoring force with the liquid crystal have a weak general anchoring force and good compatibility with the liquid crystal composition (V1- It is also preferred to use a mixture with the compound 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, a compound represented by the following general formula (Vc) is preferable in terms of increasing the reaction rate, and the pretilt angle is thermally stable. This is preferable. Furthermore, a desired pretilt angle can be obtained by adjusting the number of carbon atoms of Sp ¹ , Sp ² and Sp ³ as necessary. The relationship between pretilt and the number of carbon atoms shows the same tendency as in the case of two functional groups.

(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 each independently represent a single bond, having 1 to 12 carbon atoms. Represents an alkylene group or —O— (CH ₂ ) _s — (wherein s represents an integer of 2 to 7 and an oxygen atom is bonded 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 a single bond, J represents a 1,4-phenylene group, a trans-1,4-cyclohexylene group or Represents a single bond, and all 1,4-phenylene groups in the formula may have an arbitrary hydrogen atom substituted with a fluorine atom.)
It is also preferable to use a compound having a photo-alignment function as the polymerizable compound. Among them, it is preferable to use a compound that exhibits photoisomerization.

As the polymerizable compound having a photo-alignment function, specifically, in the general formula (Vb),
X ¹ and X ² each independently represent a hydrogen atom or a methyl group, and Sp ¹ and Sp ² each independently represent a single bond, an alkylene group having 1 to 8 carbon atoms, or —O— (CH ₂ ). _s − (wherein _s represents an integer of 1 to 7 and an oxygen atom is bonded to an aromatic ring), Z ¹ represents —N═N—, and C represents 1,4-phenylene. A compound representing a group, a trans-1,4-cyclohexylene group (any hydrogen atom may be substituted by a fluorine atom) or a single bond is preferred.

  Especially, the compound represented by the following general formula (Vn) is preferable.

(In the formula, Rn1 and Rn2 each independently represent a hydrogen atom or a methyl group, and in the formula, pn and qn each independently represents an integer of 1 to 12.)
[Polymerization initiator]
As the polymerization method of the polymerizable compound used in the present invention, radical polymerization, anionic polymerization, cationic polymerization, etc. can be used, but polymerization is preferably performed by radical polymerization, radical polymerization by photo-Fries rearrangement, and initiation of photopolymerization. Radical polymerization with an agent is more preferred.

  As the radical polymerization initiator, a thermal polymerization initiator or 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, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- ( 2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl- Acetophenone series such as 2-dimethylamino-1- (4-morpholinophenyl) -butanone, 4′-phenoxyacetophenone, 4′-ethoxyacetophenone;
Benzoins such as benzoin, benzoin isopropyl ether, benzoin isobutyl ether, benzoin methyl ether, benzoin ethyl ether;
Acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide;
Benzyl, methylphenylglyoxyesters;
Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylated 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, 2,4-dichlorothioxanthone;
Aminobenzophenone series such as Michler's ketone and 4,4'-diethylaminobenzophenone;
10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphorquinone and the like are preferable. Of these, benzyldimethyl ketal is most preferred.

It is also preferable to use a plurality of polymerization initiators in consideration of radical lifetime and reactivity.
Furthermore, without using the above-described polymerization initiator, polymerization can be carried out by containing a polymerizable liquid crystal compound having a conjugated structure that absorbs ultraviolet rays as radical polymerization by photofleece rearrangement. For example, it is preferable to use a polymerizable liquid crystal compound having a conjugated structure represented by general formulas (X1c-1) to (X1c-4) instead of the polymerization initiator because the voltage holding ratio 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 composition]
The polymerizable composition used in the present invention comprises a polymerizable composition containing one or more polymerizable compounds exemplified above, a chiral compound, and a liquid crystal containing one or more liquid crystal compounds. It is preferable to contain a polymerizable composition of 1% by mass or more and less than 15% by mass in the total weight of the composition, but it may contain a polymerizable composition of 1% by mass or more and less than 12% by mass from the balance with the driving voltage. More preferably, the lower limit of the content of the polymerizable composition is preferably 2% by mass or more, and 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 4% by mass. Less than is more preferable. In addition, the polymeric composition of this invention is comprised from 1 type, or 2 or more types of polymeric compounds.

  The polymerizable composition used in the present invention contains a polymerizable composition containing one or more polymerizable compounds exemplified above, a chiral compound, and one or more liquid crystal compounds. It is also preferable to contain 15% by mass or more and less than 40% by mass of the polymerizable composition in the total weight of the liquid crystal composition, but the lower limit of the content of the polymerizable composition in this case is preferably 9% by mass or more. The upper limit is preferably less than 30% by mass, more preferably less than 25% by mass, more preferably less than 20% by mass, and more preferably less than 15% by mass. Furthermore, the polymerizable composition used in the present invention contains a polymerizable composition containing one or more polymerizable compounds exemplified above, a chiral compound, and one or more liquid crystal compounds. It is preferable to contain 5% by mass or more and less than 15% by mass of the polymerizable composition in the total weight of the liquid crystal composition, and more preferably 7% by mass or more and less than 12% by mass of the polymerizable composition. The polymerizable composition used in the present invention contains 1% by mass or more and less than 40% by mass of the polymerizable composition, so that uniaxial optical anisotropy or uniaxial refractive index anisotropy or easy orientation is achieved. It is preferable to form a polymer network having an axial direction, and it is more preferable that the optical axis or the easy alignment axis of the polymer network and the easy alignment axis of the low-molecular liquid crystal are substantially aligned.

  The polymer network includes a polymer binder in which a polymer thin film is formed by aggregating a plurality of polymer networks. The polymer binder has refractive index anisotropy indicating uniaxial orientation, low molecular 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 liquid crystal are in substantially the same direction. The feature is that it is complete. Therefore, unlike a polymer dispersion type liquid crystal or polymer network type liquid crystal which is a light scattering type 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 in that the response time of the liquid crystal element is improved by shortening the time. Furthermore, the polymerizable liquid crystal composition used in the present invention is a PSA (Polymer Sustained Alignment) that forms a polymer network layer on the entire liquid crystal element and induces a pretilt by forming a polymer thin film layer on the liquid crystal element substrate. ) Type liquid crystal composition.

  In any concentration, it is preferable to contain at least two kinds of polymerizable compounds having different Tg and adjust Tg as necessary. The polymerizable compound that is a precursor of a polymer having a high Tg is a polymerizable compound having a molecular structure that increases the crosslink density, and preferably has 2 or more functional groups. The precursor of the polymer having a low Tg preferably has a structure in which the number of functional groups is 1, or 2 or more, and an alkylene group or the like is provided as a spacer group between the functional groups to increase the molecular length. . 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 related to thermal mobility at the molecular level in the main chain and side chain of the polymer network, and has an influence on electro-optical properties. For example, when the crosslink density is increased, the molecular mobility of the main chain is lowered, the anchoring force with the low molecular liquid crystal is increased, the drive voltage is increased, and the fall time is shortened. On the other hand, when the crosslinking density is lowered so that Tg is lowered, the thermal mobility of the polymer main chain is increased, so that the anchoring force with the low-molecular liquid crystal is lowered, the driving voltage is lowered, and the fall time is increased. The anchoring force at the polymer network interface is influenced by the molecular mobility of the polymer side chain in addition to the above Tg, and the polymer is obtained by using a polymerizable compound having a polyvalent branched alkylene group and a polyvalent alkyl group. The anchoring force of the interface is lowered. In addition, the polymerizable compound having a polyvalent branched alkylene group and a polyvalent alkyl group is effective in inducing a pretilt angle and acts in the direction of reducing the polar anchoring force.

  When the polymerizable liquid crystal composition exhibits a liquid crystal phase, the polymerizable compound in the polymerizable liquid crystal composition is polymerized to increase the molecular weight of the polymerizable compound to cause phase separation of the liquid crystal composition and the polymerizable compound. . The form of separation into two phases varies greatly depending on the type of liquid crystal compound contained and the type of polymerizable compound. A phase separation structure may be formed by binodal decomposition in which an infinite number of polymerizable compound phases are generated and grown as island-like nuclei in the liquid crystal phase, and phase separation is caused by fluctuations in concentration between the liquid crystal phase and the polymerizable compound phase. A phase separation structure may be formed by spinodal decomposition. In order to form a polymer network by binodal decomposition, it is preferable that the content of at least low-molecular liquid crystal is 85% by mass or more, and the size is smaller than the wavelength of visible light by using a compound having a high reaction rate of the polymerizable compound. Innumerable nuclei of the polymerizable compound are generated to form a nano-order phase separation structure, which is preferable. As a result, when the polymerization in the polymerizable compound phase proceeds, a polymer network having a void interval shorter than the wavelength of visible light is formed depending on the phase separation structure, whereas the voids in the polymer network are caused by phase separation of the low-molecular liquid crystal phase. However, if the size of the void is smaller than the wavelength of visible light, the liquid crystal display device has high contrast, no light scattering, high contrast, strong influence of anchoring force from the polymer network, and short fall time. Is particularly preferable. The nucleation of the polymerizable compound phase in the binodal decomposition is preferably adjusted as needed as affected by changes in compatibility depending on the type and combination of compounds, reaction rate, temperature and other parameters. The reaction rate, in the case of ultraviolet polymerization, may be adjusted as appropriate to the ultraviolet exposure conditions so as to promote the reactivity depending on the functional group of the polymerizable compound, the type and content of the photoinitiator, and the ultraviolet exposure intensity. An ultraviolet exposure intensity of 20 mW / cm 2 or more is preferable. When the low-molecular liquid crystal content is 85% by mass or more, it is preferable to form a polymer network with a phase separation structure by spinodal decomposition. In spinodal decomposition, a phase separation fine structure is obtained due to fluctuations in the concentration of two phases with periodicity, so visible light This is preferable because a uniform gap interval smaller than the wavelength can be easily formed. It is preferable to form the polymer network. When the proportion of the polymerizable compound is less than 15% by mass, it is preferable to form a phase separation structure by binodal decomposition, and when it is 15% by mass or more, it is preferable to form a phase separation structure by spinodal decomposition. When the content of the polymerizable compound is increased, there exists a phase transition temperature at which the low-molecular 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 if it is low, separation occurs and a uniform phase separation structure cannot be obtained. When two-phase separation is performed according to temperature, it is preferable to form a phase separation structure at a temperature higher than the two-phase separation temperature. In any of the above cases, a polymer network is formed while maintaining the same alignment state as that of the low-molecular liquid crystal. The formed polymer network exhibits optical anisotropy so as to follow the orientation of the low-molecular liquid crystal. As the form of the liquid crystal layer in the polymer network, 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 droplets of the liquid crystal composition are dispersed in the polymer, or both are mixed. Further, there is a structure in which a polymer network layer exists starting from both substrate surfaces, and only a liquid crystal layer is provided in the vicinity of the center of the opposite substrate. In any structure, it is preferable that a pretilt angle of 0 to 90 ° of the liquid crystal composition is induced with respect to the normal direction of the liquid crystal element substrate by the action of the polymer network. The polymer network to be formed preferably has a function of aligning the coexisting low molecular liquid crystal in the alignment direction indicated by the alignment film of the liquid crystal cell, and further has a function of pretilting the low molecular liquid crystal with respect to the polymer interface direction. It is also preferable. Introducing a polymerizable compound that pretilts a low-molecular liquid crystal with respect to the polymer interface is useful and preferable for lowering the driving voltage of the liquid crystal element. Moreover, it may have refractive index anisotropy, and it is preferable to use a polymerizable compound having a mesogenic group for the function of aligning the liquid crystal in the alignment direction.

  For vertically aligned cells such as VA type, a polymerizable compound having a polyvalent alkyl group having no mesogenic group that induces vertical alignment or a polyvalent branched alkylene group may be used, and a polymerizable compound having a mesogenic group Is also preferred in combination. When a polymer network is formed in a vertically aligned cell by phase separation polymerization using the polymerizable liquid crystal composition described above, the fibrous or columnar polymer network is in the vertical direction of the low molecular liquid crystal with respect to the liquid crystal cell substrate. It is preferable that they are formed in substantially the same direction. In addition, when a vertical alignment film that induces a pretilt angle by rubbing the liquid crystal on the cell substrate surface so as to induce a tilted alignment is used, the liquid crystal is pretilted and aligned. It is preferable that a fiber-like or columnar polymer network is inclined in the same direction as the low-molecular liquid crystal.

  Furthermore, in the method of inducing the pretilt angle while applying a voltage, when polymerizing while applying a voltage in a voltage range of about 0.9 V to 2 V higher than the threshold voltage of the polymerizable liquid crystal composition, Alternatively, in the case where the columnar polymer network has a desired pretilt angle, preferably the vertical orientation such as VA type, the optical axis direction or the easy axis direction of the polymer network is relative to the normal direction of the transparent substrate before irradiation with the energy beam. The pretilt angle is preferably 0.1 to 30.0 °, more preferably 0.1 to 10.0 °, further preferably 0.1 to 5.0 °, and particularly preferably 0.1 to 3.0 °. In the case of horizontal alignment such as TN type, the optical axis direction of the polymer network or the easy axis direction of the polymer network is preferably 0.1 to 30 ° with respect to the parallel direction of the transparent substrate before irradiation with the energy beam. The pretilt angle is preferably 0.1 to 10.0 °, more preferably 0.1 to 5.0 °, still more preferably 0.1 to 3.0 °, and particularly preferably 0.1 to 2.0 °. Since it is formed so as to be inclined, it is more preferable. The fibrous or columnar polymer network formed by any method is characterized in that the two cell substrates are connected to each other. Thereby, the thermal stability of the pretilt angle is improved, and the reliability of the liquid crystal display element can be increased.

  In addition, as a method for inducing the pretilt angle of a low-molecular liquid crystal by forming a fibrous or columnar polymer network in an inclined orientation, the alkylene group between the functional group and the mesogenic group has 6 or more carbon atoms. And a bifunctional acrylate having a small pretilt angle induction angle, a functional group, and a bifunctional acrylate having a large pretilt angle induction angle in which the number of carbon atoms of the alkylene group between the mesogenic groups is 5 or more. A desired pretilt angle can be induced by adjusting the compounding ratio of these compounds.

  Furthermore, a polymerizable composition containing at least one or more polymerizable compounds as a polymerizable compound having a reversible photo-alignment function, a liquid crystal composition containing a chiral compound and one or more liquid crystal compounds. Examples thereof include a method of forming a fibrous or columnar polymer network by adding within a range of 0.01% to 1% of the total weight of the product. In this case, the trans form has a rod-like shape similar to that of the low-molecular liquid crystal and affects the alignment state of the low-molecular liquid crystal. The trans isomer contained in the polymerizable liquid crystal composition of the present invention has a low molecular weight that is aligned so that the direction of ultraviolet light travels parallel to the long axis direction of the rod-shaped molecule when ultraviolet light is exposed as parallel light from the top surface of the cell. At the same time, the liquid crystal is aligned so as to be aligned in the molecular long axis direction of the trans form. When ultraviolet rays are exposed while being inclined with respect to the cell, the molecular long axis of the trans body is oriented in the inclined direction and the liquid crystal is oriented in the inclined direction of the ultraviolet rays. That is, a pre-tilt angle is induced and a photo-alignment function is exhibited. The pretilt angle induced by crosslinking the polymerizable compound at this stage is fixed by a fibrous or columnar polymer network formed by polymerization phase separation.

  Therefore, the pretilt angle that is important for the VA type is induced by a method of separating a polymerization phase while applying a voltage, a method of separating a polymerization phase by adding a plurality of polymerizable compounds having different induced pretilt angles, and a reversible photo-alignment function. The liquid crystal element of the present invention can be produced using a method of aligning low-molecular liquid crystals and polymerizable liquid crystal compounds in the direction in which ultraviolet rays travel by using the photo-alignment function exhibited by the polymerizable compound, and separating the polymerization phase as necessary. .

  The polymerizable compound having a photo-alignment function is preferably a photoisomeric compound that absorbs ultraviolet rays to become a trans isomer, and further, the polymerizable compound having a photo-alignment function has a reaction rate of the polymerizable compound having the photo-alignment function. It is preferably slower than the reaction rate of the polymerizable compound other than the above. When UV exposure is performed, the polymerizable compound having a photo-alignment function immediately becomes a trans form, and when aligned in the light traveling direction, the surrounding liquid crystal compound including the polymerizable property is aligned in the same direction. At this time, the pre-tilt angle in the direction in which the UV phase propagates when the polymer phase separation proceeds and the long axis direction of the low molecular liquid crystal and the easy axis direction of the polymer network are aligned with the easy axis of the polymerizable compound having a photo-alignment function. Is induced.

  Furthermore, in parallel alignment cells such as IPS and FFS modes, the polymer liquid crystal composition is used for the alignment direction of the alignment film having a fibrous or columnar polymer network on the liquid crystal cell substrate surface by phase separation polymerization. The low-molecular liquid crystals are aligned in parallel, but they are formed in the same direction as the refractive index anisotropy or easy-orientation axis direction of the formed fibrous or columnar polymer network and the alignment direction of the low-molecular liquid crystals. Is preferred. Furthermore, 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 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 mesogenic group, or a polymerizable compound having a polyvalent alkylene group and a polymerizable compound having a mesogenic group. .

  Furthermore, although the electro-optical characteristics are affected by the surface area of the polymer network interface and the gap spacing of the polymer network, it is important not to cause light scattering, and the average gap spacing is preferably smaller than the wavelength of visible light. For example, there is a method of increasing the monomer composition content in order to increase the surface area of the interface and reduce the gap interval. As a result, the polymer phase is formed so that the surface area of the interface is increased by changing the polymerization phase separation structure and making the gap interval fine, 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, the phase separation rate is greatly affected by the compatibility between the low-molecular 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 as appropriate. When the compatibility is high, it is preferable to use a polymerizable compound having a high polymerization rate. 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 element of the present invention. As a method for reducing the compatibility, a method of polymerizing at a low temperature can be mentioned. When the temperature is lowered, the degree of alignment 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. Still another method includes a method in which the polymerizable liquid crystal composition is polymerized at a temperature showing a supercooled state. In this case, it is sufficient to make the temperature slightly lower than the melting point of the polymerizable liquid crystal composition. Therefore, it is preferable that the phase separation can be accelerated only by lowering the temperature by several degrees. As a result, the 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, the surface area of the polymer network interface, which is a structure that acts to shorten the fall time, has a large gap spacing. A fine polymer network structure is formed. Therefore, it is preferable that the polymerizable liquid crystal composition of the present invention is appropriately adjusted in consideration of the alignment function, the crosslinking density, the anchoring force, and the gap interval so that the fall time is shortened.

In a liquid crystal device 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. It is important to control the phase separation structure to obtain an appropriate polymer network layer structure so as to obtain switching characteristics. The polymer network layer structure will be specifically described as follows.
<Continuous structure of polymer network layer>
A structure in which 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, and the orientation axis of the polymer network and the uniaxial optical axis are substantially in the same direction as the orientation axis of the low-molecular liquid crystal It is preferable that the polymer network is formed so as to induce a pretilt angle of the low-molecular liquid crystal, and light is obtained by reducing the average gap distance of the polymer network to be smaller than the wavelength of visible light and smaller than at least 450 nm. Since scattering does not occur, it is preferable. Furthermore, in order to make the fall time of the response shorter than the response time of the low-molecular liquid crystal alone due to the interaction effect (anchoring force) between the polymer network and the low-molecular liquid crystal, it is preferable to be in the range of 50 nm to 450 nm. In order that the influence of the cell thickness of the liquid crystal is small and the fall time is as long as the cell thickness is large, at least the average gap interval is in the range of around 200 nm and the upper limit is around 450 nm. It is preferable to enter. Increasing the drive gap increases the average gap spacing. However, in order to suppress the increase in drive voltage to 25 V or less and shorten the fall response time, it is sufficient to enter the range from about 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 drive voltage from increasing within about 5V, it is preferable that the average gap interval is in the range of about 300 nm to 450 nm. Furthermore, it is also possible to control the average gap interval of the polymer network so that the falling response time is a high-speed response of 1 msec or less. Although the drive voltage may increase to 30 V or more, the average gap interval may be set between about 50 nm and about 250 nm, and in order to reduce it to 0.5 msec or less, it is preferable to set from about 50 nm to about 200 nm. The average diameter of the polymer network is in the range of 20 nm to 700 nm, contrary to the average gap spacing. As the content of the polymerizable compound increases, the average diameter tends to increase. Increasing the polymerization phase separation rate by increasing the reactivity increases the density of the polymer network and decreases the average diameter of the polymer network. 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 gap distance is 200 nm to 450 nm, the average diameter is 40 nm to 160 nm. preferable. When the polymerizable compound content is greater than 10%, a range of 50 nm to 700 nm is preferable, and a range of 50 nm to 400 nm is more preferable.
<Discontinuous structure of polymer network layer>
The distance d between the two opposing substrates is determined so that the product (retardation) of the cell thickness (d) and the effective birefringence (Δn) of the liquid crystal is about 0.275 to 0.33. When the content of the polymerizable compound is present, the polymer network layer is formed on the entire surface of the liquid crystal display element and the liquid crystal phase is continuous. When the amount necessary for the above is insufficient, the polymer network layer is formed discontinuously. When the polarity of the substrate surface such as 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. A polymer network layer, a liquid crystal layer, a polymer network layer, and a counter substrate are stacked in this order from the surface. Polymer having a laminated structure of 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 due to the action of the anchoring force between the polymer network and the low-molecular liquid crystal is exhibited and a favorable tendency is exhibited. However, since the influence of the cell thickness increases, if the fall time becomes longer as the cell thickness is increased, the thickness of the polymer network layer may be increased as necessary. The polymer network structure in the polymer network layer is such that the low-molecular liquid crystal and the easy-orientation axis or uniaxial optical axis are aligned in substantially the same direction, and the low-molecular liquid crystal is formed so as to induce a pretilt angle. Just do it. The average gap distance is preferably in the range of 90 nm to 450 nm.

  The polymerizable composition content in the total weight of the polymerizable composition containing one or more polymerizable compounds, the chiral compound, and the liquid crystal composition containing one or more liquid crystal compounds is 1 mass. % To less than 6% by mass, it is preferable to use a bifunctional monomer having a mesogenic group having a high anchoring force, and a bifunctional monomer having a short distance between functional groups and a high polymerization rate should be used. Preferably, the polymer phase separation structure is formed at a low temperature of 0 ° C. or lower. The superiority in polymerization at low temperature will be described in detail later along with experimental examples. The polymerizable composition content in the total weight of the polymerizable composition containing one or more polymerizable compounds, the chiral compound, and the liquid crystal composition containing one or more liquid crystal compounds is 6 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 a polymerized phase separation structure is formed in the range of 25 ° C. to −20 ° C. as necessary. It is preferable to make it. Furthermore, if the melting point is room temperature or higher, it is preferable to lower the melting point by about 5 ° C. because the same effect as low temperature polymerization can be obtained. The polymerizable composition content in the total weight of the polymerizable composition containing one or more polymerizable compounds, the chiral compound, and the liquid crystal composition containing one or more liquid crystal compounds is 10 mass. % To 40% by mass, the influence of the polymer binder or polymer network greatly affects the alignment and driving voltage of the low-molecular liquid crystal and increases the driving voltage. It is preferable to use a polymerizable compound having a mesogenic group having a relatively weak anchoring force. For example, a polymerizable compound having a weak anchoring force and having a mesogenic group is effective to increase the number of carbon atoms of an alkylene group between the functional group and the mesogenic group, and preferably has 5 to 10 carbon atoms. In addition, when the polymerizable compound exceeds 30% by mass, liquid crystal droplets may be dispersed in the polymer binder. Even in this case, the polymer binder has a refractive index anisotropy and is oriented on the substrate surface. It is preferable that the orientation direction indicated by the film is aligned with the optical axis direction of the polymer binder.

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 τd. On the other hand, when the anchoring force between the liquid crystal composition and the polymer interface increases, τr decreases. In order to make the sum of τd and τr less than 1.5 ms, a polymerizable composition containing one or more polymerizable compounds, a chiral compound, and a liquid crystal containing one or more liquid crystal compounds The concentration of the polymerizable compound in the polymerizable liquid crystal composition in the total weight of the composition is 1 to 40% by mass, preferably 2 to 15% by mass, and preferably 3 to 8% by mass. The following is more preferable.
<Chiral compound>
In a liquid crystal display device having a twisted liquid crystal molecular arrangement such as a TN type, an HTN type, and a VA-TN type, the liquid crystal molecular arrangement is usually different for each sub-pixel using a mask rubbing method or a photo-alignment method. A horizontal or vertical orientation having a twist angle or twist direction, or a hybrid orientation is employed. When performing alignment division processing by performing mask rubbing using a horizontal alignment film, rubbing is performed in a direction in which the liquid crystal molecular alignment is twisted approximately 90 ° between the upper and lower substrates for each sub-pixel with respect to a desired direction. Thus, the twist direction can be made uniform by providing a slight pretilt angle from the horizontal direction of the substrate. Also in the case of the vertical alignment film, by performing rubbing or photo-alignment processing in the same manner as described above, a vertical alignment inclined by about 0.1 to 1.5 ° from the vertical direction of the substrate can be obtained. On the other hand, in the case of horizontal light alignment, the pretilt angle is almost 0 ° with respect to the horizontal direction of the substrate, and the twisting direction is often not determined.

  Therefore, in either the mask rubbing method or the photo-alignment method, the addition of a chiral compound is necessary to stabilize the twist direction and align the rotation direction of the liquid crystal molecules to enable more stable and high-speed, high-speed response display. is necessary.

  As the chiral compound, a compound having a polymerizable group may be used, but in order to affect the polymerization of the polymerizable compound mixed in the liquid crystal composition, a non-polymerizable chiral compound having no polymerizable group should be used. Is preferred. As the non-polymerizable chiral chiral compound, the cyclic group-containing non-polymerizable chiral compound represented by the general formula (I) is preferably used because of good compatibility with the liquid crystal composition and the polymerizable liquid crystal composition.

(In general formula (I), Z ¹ is a 1,4-phenylene group, an alkyl group having 2 to 8 carbon atoms, or an oxyalkyl group having 1 to 7 carbon atoms (the oxygen atom is bonded to a chiral site). Represents
Z ² represents —CH ₂ —, —COO—, —OCO—, or —O—,
A ¹ and A ² each independently represents a 1,4-phenylene group or a 1,4-cyclohexylene group,
Z ³ represents —O—, —S—, —CH ₂ —, —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 -, - _{F = CF -, - CF =} CH -, - CH = CF -, - CF 2 -, - CF 2 O -, - OCF 2 -, - CF 2 CH 2 -, - CH 2 CF 2 -, - CF 2 CF ₂ —, —C≡C— or a single bond (wherein, R ^a each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, wherein z represents an integer of 1 to 4) Represent)
n represents an integer of 0 to 3, and when a plurality of A ¹ and Z ³ are present, they may be the same or different,
R ¹ is a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 8 carbon atoms, an oxyalkyl group having 2 to 7 carbon atoms (the oxygen atom is bonded to the A ² group), or 2 carbon atoms. Represents an oxyalkenyl group of ˜7 (the oxygen atom is bonded to the A ² group). )
In general formula (I), Z ³ is preferably selected from —COO—, —OCO—, —CH═CH—, —C≡C— or a single bond, n is preferably 1 or 2, and a hydrogen atom , A cyano group, an alkyl group having 1 to 8 carbon atoms, an oxyalkyl group having 2 to 7 carbon atoms (the oxygen atom is bonded to the A ² group), or an oxyalkenyl group having 2 to 7 carbon atoms (oxygen) The atom is preferably bonded to the A ² group).

  Specific examples of the compound represented by the general formula (I) include, but are not limited to, compounds represented by the following formulae.

  Examples of other preferable non-polymerizable chiral compounds include compounds represented by the following formulas, but are not limited thereto.

(In the formula, Sp ^3a and Sp ^3b each independently represent an alkylene group having 0 to 18 carbon atoms, and the alkylene group is a carbon having one or more halogen atoms, a CN group, or a polymerizable functional group. may be substituted by an alkyl group having the number of atoms of 1-8, two or more of CH ₂ groups, independently of one another each of the present in the radical is not one CH ₂ group or adjacent, an oxygen atom in the form that does not bind directly to each _{other, -O -, - S -,} - NH -, - N (CH 3) -, - CO -, - COO -, - OCO -, - OCOO -, - SCO -, - COS -Or -C≡C- may be substituted,
A1, A2, A3, A4 and A5 are each independently 1,4-phenylene group, 1,4-cyclohexylene group, 1,4-cyclohexenyl group, tetrahydropyran-2,5-diyl group, , 3-dioxane-2,5-diyl group, tetrahydrothiopyran-2,5-diyl group, 1,4-bicyclo (2,2,2) octylene group, decahydronaphthalene-2,6-diyl group, pyridine -2,5-diyl group, pyrimidine-2,5-diyl group, pyrazine-2,5-diyl group, thiophene-2,5-diyl group-, 1,2,3,4-tetrahydronaphthalene-2,6 -Diyl group, 2,6-naphthylene group, phenanthrene-2,7-diyl group, 9,10-dihydrophenanthrene-2,7-diyl group, 1,2,3,4,4a, 9,10a-octahydro Fe Trento-2,7-diyl group, 1,4-naphthylene group, benzo [1,2-b: 4,5-b ′] dithiophene-2,6-diyl group, benzo [1,2-b: 4, 5-b ′] diselenophen-2,6-diyl group, [1] benzothieno [3,2-b] thiophene-2,7-diyl group, [1] benzoselenopheno [3,2-b] selenophene-2 , 7-diyl group, or fluorene-2,7-diyl group, n, l and k each independently represent 0 or 1, and 0 ≦ n + 1 + k ≦ 3,
Z0, Z1, Z2, Z3, Z4, Z5, and Z6 are each independently —COO—, —OCO—, —CH ₂ CH ₂ —, —OCH ₂ —, —CH ₂ O—, —CH═. CH -, - C≡C -, - CH = OCH 2 CH 2 -, - OCOCH 2 CH 2 -, - CONH -, - NHCO-, or an alkyl group which may have a halogen atom C2-10 Represents a single bond,
n5 and m5 each independently represent 0 or 1,
R ^3a and R ^3b represent a hydrogen atom, a halogen atom, a cyano group, or an alkyl group having 1 to 18 carbon atoms, and the alkyl group may be substituted with one or more halogen atoms or CN. two or more CH ₂ groups not one CH ₂ group or adjacent present in the radical are each, independently of one another, in the form of oxygen atoms are not directly bonded to each other, -O -, - S -, - NH—, —N (CH ₃ ) —, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS— or —C≡C— may be substituted. )
Regarding the addition amount of the chiral compound, in the case of vertical alignment like the VA-TN type, the pitch of the liquid crystal compound contained in the polymerizable liquid crystal composition to which the chiral compound is added is P, and the cell gap is d. In this case, it is necessary to prevent the helical structure from being formed in the liquid crystal layer, and P / d is preferably 4 or more. For example, when the liquid crystal cell gap to be used is 3 μm, an amount may be added so that the pitch of the liquid crystal compound contained in the polymerizable liquid crystal composition is about 12 to 30 μm. In addition, in the case of TN type twisted approximately 90 ° and HTN type, the response speed (especially OFF response speed) is faster when the addition amount of the chiral compound is increased to a short pitch so as not to be twisted 270 °. It becomes. P / d is 2 or more, preferably 2.5 or more and 3.0 or less. In this way, a liquid crystal molecule is formed by encapsulating a nematic liquid crystal composition containing a polymerizable compound in a twisted nematic mode in which the twist direction and the rotation direction of the chiral compound coincide, and performing UV irradiation to form a polymer network in the liquid crystal bulk. The orientation is stabilized and high-speed response is realized.

  In twisted nematic liquid crystal drive display devices such as TN, HTN, and VA-TN types, the relationship between the cell gap, the amount of chiral compound added, and the twist pitch is extremely important, and at low temperatures (for example, −10 ° C.). Since the temperature dependence of the pitch of the chiral compound is different at room temperature and at room temperature (for example, 25 ° C.), UV light is applied to the polymerizable compound-containing nematic liquid crystal composition by setting it to an appropriate P / d at low temperatures. Even when a polymer network is formed by irradiating the film, if the temperature dependence of the pitch (dP / dt t: temperature) is positive when the polymerization reaction is performed at room temperature, the pitch length increases and the desired P / d is obtained. It becomes impossible to obtain a stable alignment structure. As a method of avoiding this, for example, a suitable amount of clockwise chiral compounds having dP / dt having positive and negative characteristics are mixed so that the pitch lengths at low temperature (−10 ° C.) and at room temperature are substantially the same. It needs to be adjusted.

The driving voltage of the liquid crystal display element of the present invention is not determined only by the dielectric anisotropy or 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, Japanese Patent Application Laid-Open No. 6-222320 discloses the relationship of the following formula as a description regarding the driving voltage of a polymer dispersion type liquid crystal display element.

(Vth represents a threshold voltage, 1Kii and 2Kii represent elastic constants, i represents 1, 2 or 3, Δε represents dielectric anisotropy, and <r> represents a transparent polymer substance interface. (Indicates the average gap distance, A indicates the anchoring force of the transparent polymer substance to the liquid crystal composition, and d indicates the distance between the substrates having transparent electrodes.)
According to this, the driving voltage of the light-scattering liquid crystal display element is determined by the average gap spacing at the interface of the transparent polymer material, the distance between the substrates, the elastic constant / dielectric anisotropy of the liquid crystal composition, and the transparency with the liquid crystal composition. Determined by the anchoring energy between the conductive polymer materials.

  Among these, parameters that can be controlled by the liquid crystal display device of the present invention are liquid crystal properties and anchoring force between polymers. Since the anchoring force largely depends on the molecular structure of the polymer and the molecular structure of the low-molecular liquid crystal, if a polymerizable compound having a strong anchoring force is selected, the response time can be shortened to 1.5 ms or less. At the same time, since the driving voltage increases to 30 V or higher, the liquid crystal compound and the polymerizable compound can be appropriately selected and the composition can be adjusted so that the driving voltage is 30 V or lower and the response speed is 1.5 ms or lower. preferable.

  It is preferable to adjust the composition so that the driving voltage and the response speed are balanced by appropriately blending a polymer precursor having a strong anchoring force and a polymer precursor having a weak anchoring force. On the other hand, as the physical properties of the liquid crystal composition required for lowering the driving voltage, it is particularly preferable that the dielectric anisotropy is 6 or more for the P-type liquid crystal and -3 or less for the N-type liquid crystal. . The birefringence is preferably 0.09 or more. Furthermore, it is more preferable to make the birefringence of the liquid crystal composition and the refractive index of the fibrous or columnar polymer network 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 use the liquid crystal composition with an increased or decreased birefringence so that the necessary retardation can be obtained.

  In the liquid crystal display device of the present invention, the above-mentioned liquid crystal composition is irradiated with energy rays while the temperature is set to −50 ° C. to 30 ° C., and a polymerizable compound is polymerized to have a refractive index anisotropy or an easy alignment axis. 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. This is because 1) the polymerization is performed in a state where the orientation degree of the liquid crystal molecules is increased at a low temperature, and 2) the phase separation is facilitated by reducing the compatibility between the polymer polymerized by the low temperature polymerization and the liquid crystal composition. The phase separation speed is increased and the gap distance of the polymer network becomes fine. 3) Even if a polymerizable compound having a relatively low anchoring force is used, the influence of the anchoring force seems to be strong because the gap gap is fine. This is thought to be due to the formation of a refractive index anisotropic polymer network.

Furthermore, in the liquid crystal display element of the present invention, the optical axis direction or the easy alignment axis direction of the polymer network or polymer binder having uniaxial refractive index anisotropy or easy alignment axis direction forms a pretilt angle with respect to the transparent substrate. It is preferable to adjust the strength of the electric field to control the orientation of the low-molecular liquid crystal, and by tilting it with respect to the substrate surface, the energy rays are applied while applying a voltage to the liquid crystal layer described above. It is preferable that the composition is obtained by polymerizing the polymerizable compound by irradiation to obtain a polymer having a refractive index anisotropy or an orientation easy axis direction in the liquid crystal composition. For example, in the vertically oriented VA-TN type, the current VA type cell is used by applying a voltage so that the pretilt angle is within 20 degrees with respect to the normal direction of the substrate. This is particularly preferable because it not only has an effect equivalent to a fine polymer protrusion of PSA liquid crystal or PSA liquid crystal, but also exhibits a high-speed response that cannot be realized by PSA. In addition, by applying an electric field direction from a plurality of directions to form a polymer, a multi-domain can be formed, and a viewing angle can be improved, which is more preferable. Furthermore, the alignment direction of the low-molecular liquid crystal is regulated by applying photo-alignment treatment or rubbing alignment treatment to the low-molecular liquid crystal to induce a pretilt angle at the substrate interface vertical alignment film interface. The occurrence of orientation defects is preferably suppressed, and it is also preferable to perform the orientation treatment so as to incline in a plurality of directions. The liquid crystal layer is applied with an alternating electric field in a temperature range of −50 ° C. to 30 ° C. as appropriate to a liquid crystal composition containing a polymerizable compound, and irradiated with ultraviolet rays or an electron beam, thereby providing refractive index anisotropy. Is formed in the liquid crystal so that the optical axis direction of the polymer network forms a pretilt angle with respect to the substrate surface. This pretilt angle is a liquid crystal element in which the polymer axis after polymerization is tilted with respect to the substrate surface when the polymer phase is separated in an alignment state induced by applying an electric field due to the dielectric anisotropy of the low-molecular liquid crystal It is more preferable that the polymerizable compound has a high molecular weight.
[Liquid crystal display element]
The liquid crystal display element of the present invention contains a chiral compound and a polymer or copolymer in the liquid crystal composition, and the content of the polymer or copolymer is the total mass of the liquid crystal composition and the polymer or copolymer. The liquid crystal display device has the same structure as that of the liquid crystal display element according to the prior art except that the content is 1 mass% or more and less than 40 mass%. That is, the liquid crystal display device 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 side. The liquid crystal display element of the present invention preferably has an alignment layer for aligning the liquid crystal composition on at least one transparent substrate. By applying a voltage to the alignment layer provided on the substrate and the electrode provided on the substrate, the alignment of the liquid crystal molecules is controlled. The polymer network or polymer binder has a uniaxial refractive index anisotropy or an easy axis direction, and the optical axis direction or the easy axis direction of the polymer network or the polymer binder and the easy axis direction of the low molecular liquid crystal are the same direction. Preferably there is. In this respect, it differs from a light scattering polymer network liquid crystal or polymer dispersed liquid crystal that does not have a uniaxial refractive index anisotropy or an orientation easy axis direction. Furthermore, it is preferable that the orientation easy axis direction of the alignment layer is the same as the orientation easy axis direction of the polymer network or the polymer binder. The liquid crystal layer applies an alternating electric field to a liquid crystal composition containing a polymerizable compound in a temperature range of −50 ° C. to 30 ° C. and irradiates ultraviolet rays or an electron beam, thereby providing refractive index anisotropy. The polymer network is formed in the liquid crystal so that the optical axis direction of the polymer network forms a pretilt angle with respect to the substrate surface. This pretilt angle is a liquid crystal element in which the polymer axis after polymerization is tilted with respect to the substrate surface when the polymer phase is separated in an alignment state induced by applying an electric field due to the dielectric anisotropy of the low-molecular liquid crystal It is more preferable that the polymerizable compound has a high molecular weight.

  By providing a polarizing plate, a retardation film, etc., display is performed using this orientation state. The liquid crystal display element can be applied to an operation mode such as a TN type, STN type, HTN type, or VA-TN type. As a method for improving the viewing angle, in general, an orientation division method has been devised in which one pixel is divided into sub-numbers of sub-pixels, and each sub-pixel has a different orientation direction. A display type having a twisted nematic structure such as HTN type VA-TN type is particularly preferable. Further, a liquid crystal display element is used in which the liquid crystal alignment directions of adjacent subpixels divided in two directions are substantially 180 °, and the liquid crystal alignment directions of adjacent subpixels divided in four directions are different by about 90 °. Is also preferable. Here, approximately 180 ° is preferably 179.0 ° to 181.0 °, more preferably 179.5 ° to 180.5 °, and approximately 90 ° is 89.0 °. It is preferably ˜91.0 °, and more preferably 89.5 ° to 90.5 °.

  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 the alignment film in that the liquid crystal composition contains a polymer or copolymer. Is different.

  A liquid crystal display element according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram schematically showing an alignment state of a polymer network and liquid crystal molecules formed in a vertically aligned liquid crystal display device (VA-TN type) having a twisted structure. Under the force, the polymerizable monomers are arranged in the vertical direction, and the polymerizable monomer is polymerized and fixed by UV light irradiation to form a polymer network. The polymer network formed in this way is (V1) a polymer network that extends over the upper and lower substrates, (V2) a polymer network that forms the polymer network from the upper (lower) substrate toward the liquid crystal direction, but halfway ( 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 estimated that the polymer network has approximately four types of structures in which the polymer networks are bonded (not floating).

  The polymer polymer network having anisotropy formed in this manner is almost completely separated from the liquid crystal layer, and the liquid crystal molecules are considered to be aligned between these polymer networks. The molecular alignment structure of the so-called polymer network type liquid crystal, in which liquid crystal molecules and polymer networks coexist and cause light scattering when no voltage is applied, is clearly different from that of the alignment maintaining layer that is unevenly distributed in the vicinity of the alignment film used in PSA etc. It has a completely different structure.

  As an example, a polymer network and a liquid crystal molecular alignment structure by a method using an alignment film have been shown, but even in a so-called MVA method having a structure such as a rib or a slit, a pre-tilt of a polymer network or liquid crystal molecules in the vicinity of the substrate interface is It is only slightly different depending on the intensity of the oblique electric field applied through the structure or slit, and it is presumed that the structure essentially has the structure shown in the above figure.

  In the VA-TN type liquid crystal display device having such a polymer network and liquid crystal molecular alignment by liquid crystal molecules, the anchoring force with respect to the liquid crystal molecules when no voltage is applied is a synergistic action of the anchoring force of the liquid crystal alignment film and the polymer network. As a result, it acts more strongly, and as a result, it is possible to increase the response speed when the voltage is OFF.

FIG. 2 shows a photograph of an alignment polymer phase separation structure observed with a polarizing microscope when a voltage is applied to a vertical alignment cell to make the liquid crystal in a homogeneous alignment state and UV exposure (3 mW / cm ² 60 seconds), and explanation of the photograph The figure is shown. Since the polymer network exhibits optical anisotropy, contrast between light and dark is obtained with the isotropic liquid crystal portion, and a polymer phase separation structure is observed. When the optical axis of the polymer network is aligned with the polarization direction, it becomes dark field and the polymer network is found to exhibit optical anisotropy. The polarized micrograph of FIG. 16 shows homogeneous alignment. When a polymer phase separation structure is observed in a vertical alignment cell in the same manner in a cell exposed to UV without applying voltage, the polymer network and It is shown that there is no difference in refractive index and a dark field is formed, and a polymer network is formed in a direction perpendicular to two parallel cell substrate surfaces.

  FIG. 3 is a schematic cross-sectional view showing an example of a liquid crystal display element. In FIG. 3, for convenience of explanation, each component is illustrated separately. As shown in FIG. 6, the configuration of the liquid crystal display element 1000 according to the embodiment of the present invention is sandwiched between a first transparent insulating substrate 200 and a second transparent insulating substrate 800 that are arranged to face each other. This is a longitudinal electric field type liquid crystal display element having the polymerizable liquid crystal composition (or liquid crystal layer 500). The first transparent insulating substrate 200 has a pixel electrode layer 300 formed on the surface on the liquid crystal layer 500 side. In addition, a pair of alignment films 400 that directly contact the polymerizable liquid crystal composition constituting the liquid crystal layer 500 and induce vertical alignment between the transparent insulating substrate 200 and the second transparent insulating substrate 800 of the liquid crystal layer 500. (400a, 400b), and the liquid crystal molecules in the polymerizable liquid crystal composition are aligned so as to be substantially perpendicular to the substrates 200, 800 when no voltage is applied. As shown in FIG. 6, the second substrate 800 and the first substrate 200 are sandwiched between a pair of polarizers 100 and 900 that are orthogonal to each other. Further, in FIG. 3, a color filter 600 is provided between the second substrate 800 and the alignment film 400. The form of the liquid crystal display element of the present invention may be a so-called color filter on array (COA), or a color filter may be provided between the electrode layer including the thin film transistor and the liquid crystal layer, or the electrode including the thin film transistor. A color filter may be provided between the layer and the second substrate.

  That is, the liquid crystal display element 1000 according to an embodiment of the present invention includes a first polarizing plate 100, a first substrate 200, a pixel electrode layer 300 including a thin film transistor, an alignment film 400, and a polymerizable liquid crystal composition. A configuration in which a liquid crystal layer 500, an alignment film 400, a color filter 600, a common electrode 700 formed on a second substrate, a second substrate 800, and a second polarizing plate 900 are sequentially stacked. It is.

  The first substrate 200 and the second substrate 800 can be made of a transparent material having flexibility such as glass or plastic, and one of them can be an opaque material such as silicon. The two substrates 200 and 800 are bonded together by a sealing material and a sealing material such as an epoxy thermosetting composition disposed in the peripheral region, and in order to maintain a distance between the substrates, for example, Spacer columns made of resin formed by granular spacers such as glass particles, plastic particles, alumina particles, or the photolithography method may be arranged.

  4 is an enlarged plan view of a region surrounded by a line VII of an electrode layer 300 including a thin film transistor (or also referred to as a thin film transistor layer 300) formed on the substrate in FIG. FIG. 5 is a cross-sectional view of the liquid crystal display element shown in FIG. 3 taken along the line VIII-VIII in FIG. Hereinafter, a vertical electric field type liquid crystal display device according to the present invention will be described with reference to FIGS.

  Amorphous silicon, polycrystalline polysilicon, or the like can be used for the semiconductor layer 170; however, when a transparent semiconductor film such as ZnO, IGZO (In—Ga—Zn—O), or ITO is used, light caused by light absorption can be used. This is also preferable from the viewpoint of suppressing the harmful effects of carriers and increasing the aperture ratio of the element.

  Furthermore, an ohmic contact layer 160 may be provided between the semiconductor layer 170, the source electrode 190b, and the drain electrode 180 for the purpose of reducing the width and height of the Schottky barrier. For the ohmic contact layer, a material in which an impurity such as phosphorus such as n-type amorphous silicon or n-type polycrystalline polysilicon is added at a high concentration can be used.

  The gate wiring 260, the data wiring 250, and the common line (not shown) are preferably metal films, more preferably Al, Cu, Au, Ag, Cr, Ta, Ti, Mo, W, Ni or alloys thereof. The case of using Al or its alloy wiring is particularly preferable. The insulating protective layer 18 is a layer having an insulating function, and is formed of silicon nitride, silicon dioxide, silicon oxynitride film, or the like.

  In the embodiment shown in FIGS. 4 and 5, the common electrode 600 is a flat electrode provided on the second substrate side, while the pixel electrode 210 is an electrode having a slit structure as shown in FIG. is there. That is, the common electrode 600 is disposed to face the pixel electrode 210. The pixel electrode 210 and the common electrode 600 are formed of a transparent conductive material such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and IZTO (Indium Zinc Tin Oxide).

  In the color filter 600 according to the present invention, it is preferable to form a black matrix (not shown) in a portion corresponding to a thin film transistor and a storage capacitor (not shown) from the viewpoint of preventing light leakage. The color filter 600 is usually composed of one dot of video or image from three filter pixels of R (red), G (green), and B (blue). For example, these three filters are arranged in the extending direction of the gate wiring. Yes. The color filter 600 can be produced by, for example, a pigment dispersion method, a printing method, an electrodeposition method, or a dyeing method. A method for producing a color filter by a pigment dispersion method will be described as an example. A curable coloring composition for a color filter is applied onto the transparent substrate, subjected to patterning treatment, and cured by heating or light irradiation. By performing this process for each of the three colors red, green, and blue, a pixel portion for a color filter can be manufactured. 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 pixel electrode layer 300 and the color filter 600, a pair of alignment films 400 that directly contact the polymerizable liquid crystal composition constituting the liquid crystal layer 500 to induce alignment are provided.

  When using the 90 ° twist mode such as VA-TN type, TN type, and HTN type, it is preferable to control the cell gap so that the cell gap is 1.5 to 10 μm, so that the contrast is maximized. For this purpose, the product of the refractive index anisotropy Δn of the liquid crystal and the cell thickness d is preferably 0.5 or 1.0. In consideration of the response speed of the liquid crystal display device, Δnd is around 0.5. More preferably it is. By using a liquid crystal material having a large Δn, a further increase in response speed can be expected. Furthermore, a retardation film for widening the viewing angle can also be used. Examples of the spacer include columnar spacers made of glass particles, plastic particles, alumina particles, a photoresist material, and the like. Thereafter, a sealant such as an epoxy thermosetting composition is screen-printed on the substrates with a liquid crystal inlet provided, the substrates are bonded together, and heated to thermally cure the sealant.

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

As a method for polymerizing a polymerizable compound, an appropriate polymerization rate is desirable in order to obtain good alignment performance of liquid crystals. Therefore, ultraviolet rays or electron beams, which are active energy rays, are irradiated singly or in combination or sequentially. The method of polymerizing by is preferred. When ultraviolet rays are used, a polarized light source or a non-polarized light source may be used. In addition, when polymerization is performed in a state where the polymerizable liquid crystal composition is sandwiched between two substrates, at least the substrate on the irradiation surface side must be given appropriate transparency to the active energy rays. . Moreover, for the liquid crystal composition containing a polymerizable compound,
While applying an alternating electric field to the polymerizable liquid crystal composition in a temperature range of −50 ° C. to 20 ° C., it is preferable to irradiate ultraviolet rays or electron beams. The alternating electric field to be applied is preferably an alternating current 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 type liquid crystal display element, it is preferable to control the pretilt angle from 80 degrees to 89.9 degrees from the viewpoint of alignment stability and contrast.

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

  FIG. 7 shows a rubbing direction for determining a liquid crystal molecular arrangement at the time of alignment division in which one pixel is divided into four sub-pixels when the VA-TN type, TN type, and HTN type used as the twisted nematic method are used. (Photo-alignment direction).

  FIG. 8 shows a schematic structural diagram of liquid crystal molecule alignment when a voltage of VA-TN type applied as one form of VA type is applied and when no voltage is applied.

  On the inner side (liquid crystal layer side) of the transparent electrode of the liquid crystal cell, a vertical alignment film slightly tilted (0.1 to 5.0 °) from the normal direction of the glass substrate is formed. The molecule has a twisted structure of approximately 90 ° between the upper and lower substrates.

  In the case of a VA-TN type liquid crystal display element, a vertical alignment agent is applied and baked on an ITO transparent electrode formed on two transparent glass substrates arranged opposite to each other, and then a mask is used as shown in FIG. 90 degrees twisted vertical alignment cells (4-domain VA-TN cells) with different twist directions by 90 degrees so as to be clockwise with respect to the traveling direction. . Since the mask rubbing treatment method is an inefficient production method that is troublesome and easily produces defective products due to rubbing, scuffing, etc., and is not efficient, it is a light dimerization type non-photosensitive film using a photo-alignment film having a 4-chalcone group. A contact type alignment method is preferred. In the case of the photo-alignment treatment, a 4-domain VA-TN cell can be formed by performing light irradiation using a photomask from a direction that matches FIG.

  In the case of the TN type, a substrate on which two ITO electrodes are formed after mask rubbing is performed four times in the direction shown in FIG. 7 in the same manner as in the case of the VA-TN type after applying and baking an ordinary polyimide alignment film. May be arranged opposite to each other. In this case as well, as in the case of the VA-TN type, light dimerization type horizontal photo-alignment film using cinnamic acid polymer or the like as the liquid crystal molecule alignment or photo-decomposable polyimide is used for polarization through a photomask. By irradiating with UV, a four-domain TN cell having an orientation orientation corresponding to FIG. 7 can be produced.

  In the case of the HTN type, as in the case of the VA-TN type and the TN type, a vertical alignment film is applied and baked on the surface of the ITO transparent electrode on one substrate, and a horizontal alignment film is formed on the surface of the ITO transparent electrode substrate on the opposing side substrate. After coating and baking, mask rubbing is performed four times in the direction shown in FIG. 7, or a vertical alignment film and a horizontal photo alignment film by photo-alignment are applied to the surface of each ITO substrate, and then polarized UV is applied from a predetermined direction. By irradiation, a 4-domain HTN cell having an orientation orientation matching the figure can be created.

  In any display mode, a chiral compound having a helical pitch in the same direction as the twist direction of the liquid crystal molecules generated by the alignment treatment is added to the polymerizable compound-containing nematic liquid crystal composition, and the nematic liquid crystal is sealed. By performing UV irradiation on the composition to form a polymer network, the stability of the alignment is increased, and the occurrence of reverse twist and reverse domain can be suppressed.

The polarizing plate 100 and the polarizing plate 900 can be adjusted to adjust the polarization axis of each polarizing plate so that the viewing angle and the contrast are good, and so that their transmission axes operate in the normally black mode, It is preferable to have transmission axes perpendicular to each other. In particular, any one of the polarizing plate 1 and the polarizing plate 8 is preferably arranged so as to have a transmission axis parallel to the alignment 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 to about 0.5 to 1.0 so that the contrast is maximized. Furthermore, a retardation film for widening the viewing angle can also be used.
<Low temperature polymerization characteristics>
In the liquid crystal display device of the present invention, the above-mentioned liquid crystal composition is irradiated with energy rays while the temperature is set to −50 ° C. to 30 ° C., and a polymerizable compound is polymerized to have a refractive index anisotropy or an easy alignment axis. 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. This is because 1) the polymerization is performed in a state where the orientation degree of the liquid crystal molecules is increased at a low temperature, and 2) the phase separation is facilitated by reducing the compatibility between the polymer polymerized by the low temperature polymerization and the liquid crystal composition. The phase separation speed is increased and the gap distance of the polymer network becomes fine. 3) Even if a polymerizable compound having a relatively low anchoring force is used, the influence of the anchoring force seems to be strong because the gap gap is fine. This is thought to be due to the formation of a refractive index anisotropic polymer network.

  Hereinafter, the comparison of the electro-optical characteristics in the vertical alignment type VA liquid crystal display mode between the low temperature polymerization and the room temperature polymerization will be described in detail. In order to simplify the experiment, the liquid crystal molecules have a normal structure in which 90 ° is not twisted between the upper and lower substrates.

  A composition (Δn0.102, viscosity η16.8, Δε-3.8) represented by the following (LCN-1) was prepared as an N-type liquid crystal composition. The compound represented by the formula (V1-1-2) was used as the polymerizable compound.

  N-type liquid crystal composition (LCN-1; Δn0.102, viscosity η16.8, Δε-3.8) 96% by mass, polymerizable compound (V1-1-2) 4% by mass, and polymerization photoinitiator Irgacure 651 A polymerizable liquid crystal composition (LCM-2) containing 2% by mass with respect to the polymerizable compound (V1-1-2) was prepared.

  After applying a polyimide alignment film with a cell gap of 3 μm so that liquid crystal vertical alignment (homeotropic alignment) can be obtained, rubbing alignment treatment is performed so that the pretilt angle is 1 ° to 2 ° with respect to the normal direction of the substrate surface. A parallel rubbing orientation cell with ITO was used. The solid polymerizable compound (V1-1-2) is heated to 60 ° C. and dissolved in the liquid crystal (LCN-1), and then the polymerizable compound (V1-1-2) is uniformly dissolved at room temperature and nematic. The liquid crystal phase was confirmed with a polarizing microscope. The polymerizable liquid crystal composition (LCM-2) was heated to 60 ° C. and injected into the glass cell by a vacuum injection method.

After the injection, the glass cell was taken out and the inlet was sealed with a sealing agent 3026E (manufactured by ThreeBond). 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. Thus, the polymerizable compound of the polymerizable liquid crystal composition was polymerized to obtain a VA liquid crystal display element (1). When the cell prepared between two orthogonal polarizing plates is placed, it becomes 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 alignment easy axis direction are the same direction. It was confirmed.

  A VA liquid crystal display element (2) was obtained in the same manner as above except that the polymerization temperature was −10 ° C.

  An N-type liquid crystal composition LCN-1 containing no polymerizable compound (V1-1-2) is injected and sealed in a liquid crystal cell prepared under exactly the same conditions to obtain a VA-type liquid crystal display element (3). It was.

  A 60 Hz rectangular wave is applied to the VA liquid crystal display elements (1), (2), and (3) to measure voltage-transmittance characteristics and response time, and the results are shown in the following table.

  As is apparent from the results in the above table, the VA liquid crystal display device containing a polymer obtained by polymerizing a polymerizable compound with UV light has a slightly higher driving voltage, but the response speed, particularly τd is increased. It can be seen that the effect is noticeable in polymerization at low temperatures.

  Next, FIG. 9 shows the detailed results regarding the voltage transmittance-characteristic and response speed when the polymerization temperature of the polymerizable compound is room temperature (25 ° C.) and −10 ° C. As shown in FIG. 9, it was confirmed that τd was increased by low temperature polymerization.

  The polymerizable liquid crystal composition used for cell preparation was allowed to stand at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

  Subsequently, VA type liquid crystal display devices were produced at polymerization temperatures of −10 ° C., 0 ° C., 10 ° C., and 25 ° C.

  When the voltage-transmittance characteristic was measured by applying a rectangular wave of 60 Hz, the drive voltage V90 (v) shown in FIG. 10 was shown. As shown in FIG. 10, it was confirmed that the driving voltage increased as the polymerization temperature decreased.

  The polymerizable liquid crystal composition used for cell preparation was allowed to stand at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

  Further, the response time in the VA mode was examined. The results are shown in FIG. As shown in FIG. 11, an increase in the speed of τd was confirmed by low temperature polymerization. In addition, with the gate turned on at a frequency of 60 Hz, a voltage of 1V 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 ratio. The voltage holding ratio at 25 ° C. was 99.5%, and the voltage holding ratio at 70 ° C. was 93%.

  From the above experimental results, it was confirmed that high-speed responsiveness was obtained for both τd and τr when polymerized at a low temperature than when polymer network was polymerized at room temperature. In addition, the tendency for τd and τr to be increased by lowering the polymerization temperature was the same in the TN type, HTN type, and VA-TN type containing a chiral compound.

  The vertical alignment film was subjected to anti-parallel rubbing treatment under exactly the same conditions except that the cell gap was 12 μm, and a polymer liquid crystal compound was irradiated with UV light at room temperature to produce a polymer network VA panel. When the pretilt angle was measured using a pretilt angle measurement system PSA-301 type manufactured by Toyo Corporation, the pretilt angle had a pretilt of 0.8 ° with respect to the normal direction of the substrate.

  The VA-TN type panel having a vertical alignment structure twisted by 90 ° between the upper and lower sides of the substrate is expected to have a slightly larger pretilt angle than the VA type panel due to the influence of the twisted structure. The pretilt angle can be estimated.

  In the case of the VA-TN type panel having the 90 ° twisted structure as described above, if the pretilt angle becomes too large, the deviation of the cell gap d and birefringence product Δnd from 0.5, which is the optimum value, is large. Therefore, it is desirable to suppress the inclination from the normal direction within 10.0 °.

EXAMPLES The present invention will be described in further detail with reference to examples below, but the present invention is not limited to these examples. Further, “%” in the compositions of the following Examples and Comparative Examples means “% by mass”.
(Examples 1, 2, and 3)
(TN type liquid crystal display element)
In order to induce a spontaneous twist in the bulk of the liquid crystal cell, a composition (Δn0.103, viscosity η20 mPa · s) represented by the following (LCP-1) is prepared as a P-type liquid crystal composition. A chiral compound represented by the following formula (I-1) was added to the liquid crystal composition (LCP-1) to give a twisted structure in the nematic liquid crystal layer.

  A compound represented by the following formula (V1-1-1) was used as the polymerizable compound. 100 to 97% of the P-type liquid crystal composition (LCP-1) to which 0.84% of the chiral compound represented by the formula (I-1) is added and 1.0% of the polymerizable compound (V1-1-1), respectively. %, 2.0%, 3.0%, a polymerizable liquid crystal composition in which the polymerization photoinitiator Irgacure 651 was 2% with respect to the polymerizable compound (V1-1-1) was prepared. The solid polymerizable compound (V1-1-1) was heated to 60 ° C. and dissolved in the liquid crystal (LCP-1) to which 0.84% of the chiral compound represented by the formula (I-1) was added. After that, it was confirmed with a polarizing microscope that the polymerizable compound (V1-1-1) was uniformly dissolved at room temperature to show a nematic liquid crystal phase.

As shown in FIG. 7, the surface of the glass substrate with ITO coated with the polyimide alignment film is subjected to rubbing alignment processing so that it is twisted 90 ° clockwise between the upper and lower substrates, and a TN liquid crystal cell with a cell gap of 4.9 μm is formed. The polymerizable liquid crystal composition (LCM-1) was prepared and injected into the glass cell by a vacuum injection method, and Examples 1, 2, and 3 were obtained. In this case, P / d is 3.00, and Δnd is 0.5, which is a cell parameter of the 90 ° TN type region with the highest transmittance.
Further, a nematic liquid crystal composition not containing the polymerizable compound V1-1-1 was sealed in a liquid crystal cell in the same procedure as described above to obtain Comparative Example 1.

After the injection, the glass cell was taken out and the inlet was sealed with a sealing agent 3026E (manufactured by ThreeBond). 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. Thereby, the polymerizable compound in the polymerizable liquid crystal composition was polymerized to obtain a TN type liquid crystal display element in which a polymer network was formed in the nematic liquid crystal layer. When a cell prepared between two orthogonal polarizing plates is placed so that the rubbing treatment direction and the polarization axis direction coincide with each other, a bright field is obtained, and a 90 ° twisted alignment layer having no reverse twist or reverse domain is obtained. It was confirmed.

  The polymerizable liquid crystal composition used for cell preparation was allowed to stand at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

  The following table shows the results of measuring voltage-transmittance characteristics and response speed by applying a rectangular wave of 60 Hz.

  From the results of Examples 1 to 3, the falling speed τd is increased in all cases. In the region where the addition amount of the polymerizable compound is 1% to 3%, the fall time τd increases as the addition amount of the polymerizable monomer increases, but the rise time τr is affected by the increase of the V90 voltage (saturation voltage). In Example 3 where 3% was added, the total of the rising speed τr and the falling speed τd was (τr + τd) = 11.8 ms, which was 17.3 ms when no polymerizable monomer was added. It was confirmed that the response speed was increased by about 1.5 times.

  When the pretilt angles of the liquid crystal panels of Examples 1, 2, 3 and Comparative Example 1 were measured using a pretilt angle measurement system PSA-301 type manufactured by Toyo Technica, the obtained pretilt angles were respectively measured in the horizontal direction of the substrate. From 1, 4 °, 1.6 °, 2.2 °, and 1.2 °. Although there is a tendency that the pretilt angle is slightly increased depending on the amount of the polymerizable compound added, it seems that there is almost no change in consideration of measurement errors.

The value of the pretilt angle depends greatly on the alignment film used and the type of polymerizable compound,
In the case of a TN type panel having a 90 ° twisted structure, if the pretilt angle becomes too large, the deviation of the cell gap d and birefringence product Δnd from 0.5, which is the optimum value, increases and the transmittance decreases. Therefore, it is desirable to suppress the inclination of the substrate from the horizontal direction within 10.0 °.
(Examples 4, 5, and 6)
(4-domain TN type liquid crystal display element with photo-alignment film)
The polymer photo-alignment material represented by the following formula (P1) is dissolved in N-methyl-2-pyrrolidone (hereinafter NMP), 2-butoxyethanol is added, and the weight ratio is NMP: 2-butoxyethanol: polymer light. It adjusted so that it might become alignment material = 47.5: 47.5 :: 5, It filtered using the MS PTFE syringe filter (5um, 1um, 0.45um) by a menbrane solution company, and obtained the photo-alignment film | membrane solution. The solution is spin-coated on an IPS3035-2up substrate made of FPD solution and a counter substrate using a spin coater IH-DX-2 made by Mikasa Co., Ltd., and then hot made by AS ONE Co., Ltd. The plate was dried on a digital hot plate NINOS ND1 at 80 ° C. for 3 minutes and further dried at 150 ° C. for 5 minutes in an air atmosphere using an oven DO-600FA manufactured by AS ONE. After drying, it was gradually cooled to room temperature. Next, the photo-alignment film of the present invention was prepared by irradiating the dried film with 150 mJ / cm ^{2 of} 313 nm linearly polarized light for 7.5 seconds using a Mejiro Precision Polarized Irradiator. Using a seal dispenser manufactured by Musashi Engineering Co., Ltd., struct bond XN-21-S manufactured by Mitsui Chemicals Co., Ltd. was applied to the IPS substrate side. After coating, the sealant was dried at 90 ° C. for 30 minutes, and the substrates were bonded together. After bonding the substrates, heating was performed at 150 ° C. for 90 minutes to prepare a glass cell. After cooling to room temperature, a composition (Δn0.103, viscosity η20 mPa · s) represented by the above (LCP-1) is prepared as a P-type liquid crystal composition in a cell having a cell gap of 4.9 μm, and a liquid crystal cell In order to induce spontaneous twisting in the bulk of the liquid crystal, the chiral compound represented by the above formula (I-1) is added to the P-type liquid crystal composition (LCP-1), and a right-twisted structure in the bulk It was made to have.

The polymerizable compound (V1-1-1) 1.0 is added to 100 to 97% of the P-type liquid crystal composition (LCP-1) to which 0.84% by mass of the chiral compound represented by the formula (I-1) is added. %, 2.0%, 3.0%, a polymerizable liquid crystal composition in which the polymerization photoinitiator Irgacure 651 was 2% with respect to the polymerizable compound (V1-1-1) was prepared. A TN type liquid crystal display in which a polymer network is formed in a liquid crystal bulk by irradiating ultraviolet rays having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics Co., Ltd.) at 25 ° C. for 300 seconds. Examples 4, 5, and 6 were obtained as elements.

  Further, a nematic liquid crystal composition containing no polymerizable compound (V1-1-1) was sealed in a liquid crystal cell in the same procedure as in Examples 4 to 6, and Comparative Example 2 was obtained.

  When a cell prepared between two orthogonal polarizing plates is placed so that the rubbing treatment direction and the polarization axis direction coincide with each other, a bright field is obtained, and a 90 ° twisted alignment layer having no reverse twist or reverse domain is obtained. It was confirmed.

  The polymerizable liquid crystal composition used for cell preparation was allowed to stand at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

  The following table shows the results of measuring voltage-transmittance characteristics and response speed by applying a 60 Hz rectangular wave in the same procedure as above.

In each of Examples 4 to 6, the falling speed τd is increased. In the region where the addition amount of the polymerizable compound is 1% to 3%, the fall time τd increases as the addition amount of the polymerizable compound increases, but the rise time τr is affected by the increase of the V90 voltage (saturation voltage). In Example 6 where 3% was added, the total of the rising speed τr and the falling speed τd was (τr + τd) = 13.6 ms, and 19.9 ms when no polymerizable monomer was added. It was confirmed that the response speed was increased by about 1.5 times. It was confirmed that the alignment regulating force when the photo-alignment treatment is performed is slightly weaker than that in the case of rubbing, and the effect of high-speed response of τd tends to be low as a result.
(Examples 7, 8, 9, 10, 11)
(VA-TN type liquid crystal display element)
As shown in FIG. 7, a VA-TN liquid crystal cell having a cell gap of 4.9 μm and aligned by light in four different directions twisted by 90 ° was produced to produce a VA-TN liquid crystal display element.

Specifically, a photo-alignment film coating solution having a 4-chalcone group was applied to the first substrate and the second substrate by spin casting, and then baked at 180 ° C. for 60 minutes to form an alignment film. Subsequently, as shown in FIG. 7, along the orientation directions shown in four different directions twisted by 90 °, P-polarized light having a wavelength of 365 nm and an intensity of 3 mW / cm ² is applied to the orientation film for 400 seconds. By irradiating, alignment treatment by light irradiation was performed.

  When the pretilt angle was measured, the pretilt angle of the liquid crystal molecules in the vicinity of the first alignment film and in the vicinity of the second alignment film was 88.5 °. The constituent molecules of the alignment film have a 4-chalcone photofunctional group (photosensitive group) in the side chain of the polymer chain, but by this photo-alignment treatment, the photofunctional group forms a dimer by a dimerization reaction, A crosslinked structure was formed. In this example, each pixel of the first substrate was divided into two alignment processing regions, and light was irradiated from opposite directions. Similarly, each pixel on the second substrate was divided into two alignment treatment regions and irradiated with light from opposite directions. And after performing seal formation, spacer dispersion | spreading, etc., in the board | substrate bonding process, it bonded together so that the orientation process direction might orthogonally cross the 1st board | substrate and the 2nd board | substrate. As a result, four domain regions having different twist directions of liquid crystal molecules were formed in each pixel.

  In the following N-type liquid crystal composition (LCN-1) containing 0.63% by mass of a chiral compound represented by the following formula (I-1), the following formula (V1-1-1) and the following formula (V1-1) -2) was added to prepare a polymerizable liquid crystal composition shown in the following table. In the same manner as in Examples 1 to 6, the polymerizable liquid crystal composition was injected into the liquid crystal panel and sealed, then irradiated with UV light, and VA-TN type by the photo-alignment treatment of Examples 7, 8, 9, 10, and 11 A polymer network liquid crystal display panel was produced. The cell gap was 4,9 μm. Further, a VA-TN liquid crystal panel in which only a liquid crystal composition (LCN-1) containing 0.63% by mass of a chiral compound represented by the following formula (I-1) not containing a bifunctional monomer is enclosed is a comparative example. It was set to 3.

A VA-TN type in which an ultraviolet ray having an irradiation intensity of 15 mW / cm ² through an ultraviolet cut filter L-37 (manufactured by Hoya Candeo Optronics) was irradiated at 25 ° C. for 300 seconds, and a polymer network was formed in the liquid crystal bulk. A liquid crystal display element was obtained. When a cell made between two orthogonal polarizing plates is placed so that the photo-alignment processing direction coincides with the polarization axis direction or the transmission axis direction, all four regions having different twist directions by 90 ° are all bright fields, and are neat. It was confirmed that a 90 ° twisted alignment layer having no reverse twist or reverse domain divided into four regions was obtained.

  The polymerizable liquid crystal composition used for cell preparation was allowed to stand at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

  The following table shows the results of measuring the voltage-transmittance characteristics and response speed of a liquid crystal panel obtained by applying a rectangular wave of 60 Hz in the same procedure as described above.

  In each of Examples 7 to 11, the falling speed τd is increased. In the region where the addition amount of the polymerizable compound is from 1% to less than 2%, the fall time τd increases as the addition amount of the polymerizable monomer increases, but the rise time τr is affected by the increase of the V90 voltage (saturation voltage). However, when the addition amount is 2% or more, the liquid crystal molecular alignment structure is properly aligned, so that the rising response speed τr is also increased. Further, when the addition amount is about 10%, the influence of the orientation regulating force of the polymer network appears remarkably, and in Example 11, the falling speed τd is 1.8 ms, which is four times faster than the addition of the polymerizable compound. We were able to.

  The rise time also has the effect of increasing the drive voltage, but 1.2 ms, which is about 5 times faster than 6.0 ms when no polymerizable monomer is added, has been achieved. It was confirmed that the total fall time τd (τr + τd) = 3.0 ms and a high-speed response of 4.5 times or more of 13.9 ms when no polymerizable monomer was added were confirmed.

When the pretilt angle of the liquid crystal panels of Examples 7, 8, 9, 10, 11, and Comparative Example 3 was measured using a pretilt angle measurement system PSA-301 type manufactured by Toyo Technica, the obtained pretilt angle was They were 0.6 °, 0.8 °, 0.7 °, 1.0 °, 1.2 °, and 0.5, respectively, from the normal direction of the substrate. Although there is a tendency that the pretilt angle is slightly increased depending on the amount of the polymerizable compound added, it seems that there is almost no change in consideration of measurement errors. It appears that the pretilt angle is different for different types of polymerizable monomers.
(Examples 12, 13, and 14)
(HTN type liquid crystal display element)
A photo-alignment film coating solution having a 4-chalcone group having vertical alignment was applied to the first substrate by spin casting, and then baked at 180 ° C. for 60 minutes to form an alignment film. Subsequently, as shown in FIG. 7, along the orientation directions shown in four different directions twisted by 90 °, P-polarized light having a wavelength of 365 nm and an intensity of 3 mW / cm ² is applied to the orientation film for 400 seconds. By irradiating, alignment treatment by light irradiation was performed.

  Next, the horizontal light alignment film (P1) used in Examples 4, 5, and 6 was used for the second substrate, and the horizontal light alignment treatment by polarized light irradiation was performed in exactly the same procedure. A vertical alignment substrate and a horizontal alignment substrate with ITO transparent electrodes that have been subjected to alignment treatment in four directions are opposed to each other as shown in FIG. 7, and a cell is interposed through a sealing material containing a silica spacer having a particle size of 4.9 μm. An HTN liquid crystal cell with a gap of 4.9 μm was produced. In this HTN type liquid crystal cell, a composition (Δn0.103, viscosity η20 mPa · s) represented by (LCP-1) is prepared as a P type liquid crystal composition, and spontaneous twist is induced in the bulk of the liquid crystal cell. Therefore, 0.84% by mass of the chiral compound represented by the formula (I-1) is added to the P-type liquid crystal composition (LCP-1) so as to have a right-handed structure in bulk. did. 100% to 97% of a P-type liquid crystal composition (LCP-1) to which 0.84% by mass of a chiral compound represented by the formula (I-1) is added, 1.0% of a polymerizable compound (V1-1-1) 2.0%, 3.0%, a polymerizable liquid crystal composition in which the polymerization photoinitiator Irgacure 651 was 2% with respect to the polymerizable compound (V1-1-1) was prepared. Light irradiation was performed to obtain HTN type liquid crystal display elements, Examples 12, 13, and 14 in which a polymer network was formed in the liquid crystal bulk.

  In addition, an HTN liquid crystal cell containing no bifunctional monomer was prepared and used as Comparative Example 4.

  When a cell produced between two orthogonal polarizing plates is placed so that the alignment treatment direction coincides with the polarization axis direction or the transmission axis direction, all four regions having different twist directions by 90 ° all have bright fields, and neatly 4 It was confirmed that a 90-degree twisted HTN alignment layer that was divided into regions and had no reverse twist or reverse domain was obtained.

  The polymerizable liquid crystal composition used for cell preparation was allowed to stand at 20 ° C. for 1 week, and it was confirmed that there was no crystallization by the polymerizable compound.

  The following table shows the results of measuring voltage-transmittance characteristics and response speed by applying a 60 Hz rectangular wave in the same procedure as above.

  In each of Examples 12 to 14, the falling speed τd is increased. As in the case of the VA-TN type liquid crystal display element, in the region where the addition amount of the polymerizable compound is 1% to 3%, the fall time τd increases as the addition amount of the polymerizable compound increases, but the rise time The time τr tends to be slightly delayed due to the increase in the V90 voltage (saturation voltage). However, in the region where 3% is added, the sum of the rise time τr and the fall time τd (τr + τd) = 14.8 ms, and the high-speed response can be achieved that is twice as high as 22.0 when the polymerizable compound is added. It was confirmed that

  The above technique can be applied not only to a moving image display device such as a TV having high-speed response but also to a field sequential method that does not require a color filter. In addition, it is expected to be applied to ultra-large and high-definition 4K × 2K-TV, 4K × 8K-TV, etc.

  DESCRIPTION OF SYMBOLS 1 ... Polarizing plate, 2 ... 1st transparent insulating substrate, 3 ... Electrode layer, 4 ... Alignment film, 4a ... Alignment direction, 5 liquid crystal layer, 6 ... Color filter, 7 ... 2nd transparent insulating substrate, 8 ... Polarization Plate 9: Continuous or discontinuous polymer network, 100 ... Polarizing plate, 110 ... Gate electrode, 120 ... Gate insulating layer, 130 ... Semiconductor layer, 140 ... Protective layer, 160 ... Drain electrode, 190b ... Organic insulating film, 200 DESCRIPTION OF SYMBOLS ... 1st board | 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 transistor layer, 400 ... Alignment film , 500 ... Liquid crystal layer, 510 ... Liquid crystal display device, 512 ... Pixel electrode, 512a ... Pixel trunk electrode, 512b ... Pixel branch electrode, 512c ... Pixel slit, 51 ... scanning lines, 517 ... signal wire, 600 ... common electrode, 700 ... color filter, 800 ... second substrate, 900 ... polarizing plate, 1000 ... liquid crystal display device

Claims (13)

  Polymerizable composition containing one or more polymerizable compounds in a liquid crystal composition containing one or more liquid crystal compounds sandwiched between two transparent substrates having electrodes on at least one side A polymer or copolymer that is a cured product of the above and a chiral compound, and the content of the polymerizable composition in the total weight of the polymerizable composition, the chiral compound, and the liquid crystal composition is 1% by mass or more and 40%. The liquid crystal display element which is less than mass%.   The liquid crystal display element according to claim 1, wherein the polymer or copolymer in the liquid crystal composition forms a polymer network and has an alignment layer for aligning the liquid crystal composition on a transparent substrate.   3. The liquid crystal according to claim 2, wherein the polymer network has uniaxial refractive index anisotropy, and an optical axis direction or an easy axis direction of the polymer network and an easy axis direction of the liquid crystal composition are the same direction. Display element.   The liquid crystal display element according to claim 1, wherein the liquid crystal composition has a pretilt angle of 0 to 90 ° with respect to the normal direction of the transparent substrate.   The liquid crystal display element according to claim 2, wherein a polymer network layer having a thickness of at least 0.5% of the cell thickness with respect to the cell cross-sectional direction is formed.   The optical axis direction or the easy axis direction of the polymer network has a pretilt angle of 0.1 to 30.0 ° with respect to the normal direction or horizontal direction of the transparent substrate. A liquid crystal display element according to 1. The liquid crystal display element of any one of Claims 1-6 containing 1 type, or 2 or more types of compounds chosen from the compound represented by the following general formula (P) as a polymeric compound.

(In the formula, Z ^p1 is a fluorine atom, a cyano group, a hydrogen atom, an alkyl group having 1 to 15 carbon atoms in which a hydrogen atom may be substituted with a halogen atom, or a hydrogen atom in which a hydrogen atom is substituted. A good alkoxy group having 1 to 15 carbon atoms, a alkenyl group having 1 to 15 carbon atoms in which a hydrogen atom may be substituted with a halogen atom, and 1 to 1 carbon atoms in which a hydrogen atom may be substituted with a halogen atom 15 alkenyloxy groups or -Sp ^p2 -R ^p2 ,
R ^p1 and R ^p2 are each independently the following formulas (R-I) to (R-IX):

In the formulas (RI) to (R-IX), R ^{2 to} R ⁶ are independently of each other a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the number of carbon atoms. 1 to 5 halogenated alkyl groups, W is a single bond, —O— or a methylene group, T is a single bond or —COO—, p, t and q are each independently 0, Represents 1 or 2,
Sp ^p1 and Sp ^p2 each represent a spacer group, and Sp ^p1 and Sp ^p2 each independently represent a single bond, an alkylene group having 1 to 12 carbon atoms, or —O— (CH ₂ ) _s — (wherein s is L 1 represents an integer of 1 to 11, and an oxygen atom is bonded to an aromatic ring.) L ^p1 and L ^p2 each independently represent a single bond, —O—, —S—, —CH ₂ —, _{-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— (wherein, R ^a each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, wherein z is an integer of 1 to 4) Represents)
M ^p2 represents 1,4-phenylene group, 1,4-cyclohexylene group, anthracene-2,6-diyl group, phenanthrene-2,7-diyl group, pyridine-2,5-diyl group, pyrimidine-2, 5-diyl group, naphthalene-2,6-diyl group, indane-2,5-diyl group, 1,2,3,4-tetrahydronaphthalene-2,6-diyl group or 1,3-dioxane-2,5 -Represents a diyl group, but M ^p2 is unsubstituted or an alkyl group having 1 to 12 carbon atoms, a halogenated alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a carbon atom ^May be substituted with a halogenated alkoxy group of formulas 1 to 12, a halogen atom, a cyano group, a nitro group or —R ^p1 ;
M ^p1 represents the following formulas (i-11) to (ix-11):

(In the formula, it binds to Sp ^p1 with ★ and binds to L ^p1 or L ^p2 with ★★),
M ^p3 represents the following formulas (i-13) to (ix-13):

(In the formula, it binds to Z ^p1 with ★ and binds to L ^p2 with ★★),
m ^{p2 to} m ^p4 each independently represents 0, 1, 2 or 3, and m ^p1 and m ^p5 each independently represent 1, 2 or 3, but when a plurality of Z ^p1 are present, May be the same or different. When a plurality of R ^p1 are present, they may be the same or different. When a plurality of R ^p2 are present, they may be the same. They may be different, they may be the same or different when multiple Sp ^p1 are present, and they may be the same or different when multiple Sp ^p2 are present, When a plurality of L ^p1 are present, they may be the same or different, and when a plurality of M ^p2 are present, they may be the same or different. ) The liquid crystal display element of any one of Claims 1-8 containing the liquid crystal compound represented by the following general formula (LC) as a liquid-crystal composition.

(In the general formula (LC), R ^LC represents an alkyl group having 1 to 15 carbon atoms. One or two or more CH ₂ groups in the alkyl group are not directly adjacent to each other. -O-, -CH = CH-, -CO-, -OCO-, -COO- or -C≡C- may be substituted, and one or more hydrogen atoms in the alkyl group may be optionally substituted A ^LC1 and A ^LC2 each independently represents a group selected from the group consisting of the following groups (a), (b) and (c).
(A) trans-1,4-cyclohexylene group (one CH ₂ group present in this group or two or more CH ₂ 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 present in this group or two or more non-adjacent CH groups 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.
One or two or more hydrogen atoms contained in the group (a), group (b) or group (c) may be 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—, —OCF ₂ —, —CF ₂ O—, —COO— or —OCO— is represented.
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 may be —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C, so that the oxygen atom is not directly adjacent. ≡C—, —CF ₂ O—, —OCF ₂ — may be substituted, and one or more hydrogen atoms in the alkyl group may be optionally substituted with a halogen atom.
a represents an integer of 1 to 4. When a represents 2, 3 or 4, and there are a plurality of ^ALC1s in the general formula (LC), the plurality of ^ALC1s may be the same or different, and there are a plurality of ^ZLCs A plurality of Z ^LCs may be the same or different. )   The liquid crystal display element according to claim 1, wherein the cell structure is a VA-TN type, a TN type, or an HTN type.   The liquid crystal alignment direction of adjacent subpixels divided in two directions is substantially 180 °, and the liquid crystal alignment direction of adjacent subpixels divided in four directions is different by approximately 90 °. 2. A liquid crystal display element according to item 1.   A liquid crystal composition containing one or more liquid crystal compounds sandwiched between two transparent substrates each having an electrode on at least one side, and a polymerizable composition containing one or more polymerizable compounds A polymer or copolymer that is a cured product and a chiral compound are contained, and the content of the polymerizable composition in the total weight of the polymerizable composition, the chiral compound, and the liquid crystal composition is 1% by mass or more and 40% by mass. The liquid crystal display element formed by polymerizing the polymerizable compound in the composition which is less than% by irradiating energy rays.   The liquid crystal display element according to claim 11, wherein the polymerizable compound in the composition is polymerized by irradiating energy rays at a temperature of −50 ° C. to 30 ° C.   By irradiating the polymerizable compound in the composition with energy rays while applying a voltage such that the pretilt angle with respect to the normal direction or horizontal direction of the transparent substrate before irradiation with energy rays is 0.1 to 30 °. The liquid crystal display element according to claim 11 or 12, wherein the liquid crystal display element is polymerized.

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