KR101373675B1 - Polymerizable mesogens having improved photoreactive efficiency and polymerizable liquid crystal compositions containing the same - Google Patents

Abstract

The present invention relates to a polymerizable mesogen and a polymerizable liquid crystal composition comprising the same, and specifically, the polymerizable mesogen compound of the present invention is improved at relatively low energy by introducing methoxy acrylate into a photoreactive group. Polymeric liquid crystal composition, especially polymerizable liquid crystal display for liquid crystal display of polymer stabilization orientation type, because it has photoreaction efficiency and not only excellent solubility with host liquid crystal due to asymmetric structure, but also effect of improving stability of pretilt angle after photocrosslinking. It can be usefully used.

Description

Polymerizable mesogens having improved photoreactive efficiency and polymerizable liquid crystal compositions containing the same

The present invention relates to a polymerizable mesogenic compound having an improved photoreaction efficiency by introducing an alpha methoxyacrylate group into a photoreactive group and a polymerizable liquid crystal composition comprising the same.

As high-level digitization and informationization are accelerating, many information technology (IT) devices are being used in daily life, and display technology for them is also developing. Among the electronic displays that have been used in the past, CRT (Cathode Ray Tube) monitors, which have been used for TVs and computer monitors, are the most representative. CRT monitors, however, are bulky and heavy in weight, making them difficult to scale and port, have high power consumption, and are gradually replacing other flat panel displays with higher driving voltages.

LCDs (flat panel displays), plasma display panels (PDPs), and organic light emitting diodes (OLEDs) are typical examples of flat panel displays for overcoming the limitations of CRT. LCDs that incorporate liquid crystal and semiconductor technologies are thin, light, and low in power consumption, and are currently being used in large TVs, personal computer monitors, display devices of various measurement devices, portable multimedia players (PMPs) (Moving Picture Experts Group) -1 Audio Layer-3) devices, navigation devices of automobiles, mobile phones and the like. In order to realize a high-quality large-sized LCD, a wide viewing angle, a high brightness, a high contrast ratio, and a fast response speed are required.

The liquid crystal display has a liquid crystal cell and a polarizing plate. The polarizing plate is composed of a protective film and a polarizing film, which can be produced by dyeing a polarizing film made of a polyvinyl alcohol film with iodine, stretching, and laminating both sides with a protective film. For example, in a transmissive LCD, the polarizing plate may be mounted on both sides of the liquid crystal cell, and further, an optical compensation sheet having one or more optically anisotropic layers may be disposed. On the other hand, in a reflective LCD, a reflective plate, a liquid crystal cell, at least one optical compensation sheet, and a polarizing plate are arranged in this order. A liquid crystal cell is composed of a liquid crystal molecule, two substrates for sealing it, and an electrode layer for applying a voltage to the liquid crystal molecules.

The liquid crystal cell displays ON and OFF due to the difference in the alignment state of the liquid crystal molecules, and can be applied to any of the transmissive type and the reflective type, and thus TN (Twisted nematic), IPS (in-plane switching), and OCB (Optically Compensatory). Various types of liquid crystal displays are being developed such as Bend, Vertically Aligned (VA), Electrically Controlled Birefringence (ECB), and Super Twisted Nematic (STN). In addition, each of these types has a unique liquid crystal arrangement and has a unique optical anisotropy. Therefore, a variety of optically anisotropic compensation films are required to compensate for changes in the optical axis of linearly polarized light due to the optical anisotropy of these liquid crystal types.

A liquid crystal compound having a polymerizable group can be applied to an optical element such as a polarizing plate or a retardation plate in order to compensate the optical anisotropy of the liquid crystal mode. Such an optical element can be obtained by polymerizing an optically anisotropic polymerizable liquid crystal in a liquid crystal state and immobilizing the state, and the polymerizable liquid crystal can be polymerized while keeping an aligned state after performing proper orientation control in a liquid crystal state. Therefore, a polymer having various optical anisotropy can be obtained by immobilizing the orientation state of the liquid crystal skeleton in a state of homogeneous orientation, hybrid orientation, oblique orientation, homeotropic orientation, twist orientation and the like.

The polymer having the homogeneous orientation can be used in combination with, for example, a half-wave plate, a quarter-wave plate, or a film having another optical function, and the polymer having a hybrid orientation can be used in a TN- It can be applied as a compensation plate. In addition, the polymer having homeotropic orientation can improve viewing angle characteristics of the polarizing plate by combining with films having other optical functions. If the direction of the optical axis is in the nz direction and the refractive index in the direction perpendicular to the optical axis direction is larger than the refractive index in the direction orthogonal to the optical axis direction, In the ellipsoid, it is classified as a positive c-plate. The positive c-plate can be applied to the optical compensation of an IPS-type liquid crystal display that is horizontally aligned in combination with a film having another optical function, in particular, for improving the viewing angle characteristics of a polarizing plate.

In addition, the liquid crystal compound having a polymerizable group is a polymer stabilized alignment (PSA) or a polymer stabilized vertical alignment (PS-VA) among VA type liquid crystal displays, which are widely used in high-end monitors and large TVs. Aligned) can be used for liquid crystal display.

A liquid crystal cell of a VA type liquid crystal display includes a host liquid crystal having a generally negative dielectric anisotropy between two transparent electrodes, and in the OFF state in which no voltage is applied, these liquid crystal molecules are oriented perpendicular to the electrode surface. On the other hand, when the voltage is applied to the electrodes, the liquid crystal molecules are oriented parallel to the electrode surface. According to the vertical and horizontal alignment phenomenon of the liquid crystal depending on whether or not the voltage is applied, the opening and closing of the light emitted from the backlight passing through the polarizing plate can be controlled. In the case of such a VA type liquid crystal display, there is a disadvantage in that the response speed is very great if the direction that is oriented in parallel when the voltage is applied to the electrode is not determined in advance.

The PSA or PS-VA type is a method for controlling the inclination of the vertically oriented liquid crystal in the liquid crystal cell. The PSA or PS-VA type mixes the mesogenic compound polymerizable by ultraviolet rays together with the host liquid crystal in the liquid crystal cell. In this case, the photoreactive mesogen compound used must move together in the direction in which the host liquid crystal lies when the voltage is applied to the electrode through interaction with the vertically aligned liquid crystal. If the voltage is applied, the host liquid crystal is rapidly aligned in the oblique direction, and a high-speed response can be realized.

Conventionally, in Patent Documents 1 to 3, the polymerizable mesogenic compound for liquid crystal display of PSA or PS-VA type has low photoreaction efficiency and has a problem of lowering voltage holding ratio and long-term reliability due to unreacted monomer remaining without polymerization. . Another problem with low absorption at long wavelengths in the photoreactor is the large exposure requirement for polymerization. These high energies have become a limiting factor in the structural design of host liquid crystals and reactive mesogen compounds.

Patent document 4 discloses a liquid crystal display device including an oriented base film oriented to have a line gradient and an orientation film having a double layer of alignment control film having a polymerized mesogen represented by the following formula:

P ₁ -A _1- (Z ₁ -A ₂ ) n-P ₂

Where

P ₁ and P ₂ are independently selected from acrylate, methacrylate and the like;

A ₁ and A ₂ are independently selected from 1,4-phenylene and naphthalene-2,6-diyl.

Further, Patent Document 5 discloses a new mesogen compound represented by the following formula:

Where

,

등으로부터 선택된다.
X is

,

And the like.

In addition, Patent Document 6 discloses a polymer stabilized liquid crystal composition characterized by containing a polymerizable compound represented by the following formula:

.

.

Furthermore, Patent Document 7 provides a compound having the following formula:

.

.

As described above, however, there has been no report on the polymerizable mesogen compound and the polymerizable liquid crystal composition including the same, by introducing methoxy acrylate into the photoreactive group, thereby improving the photoreaction efficiency.

The polymerizable mesogen compound used in the PSA or PS-VA type liquid crystal display must not only have high photoreaction efficiency but also have high solubility with the host liquid crystal because the liquid crystal cell is prepared by mixing with the host liquid crystal. Furthermore, an appropriate core is required to provide stability to the pretilt angle of the mesogen compound inclined in the lying direction of the host liquid crystal.

Accordingly, the present inventors have been researching with interest for mesogen compounds having high photoreaction efficiency, and the polymerizable mesogen compound incorporating a methoxyacrylate group into the photoreactive group of the present invention has high polymerization efficiency. It is possible to use it as a polymerizable liquid crystal composition for liquid crystal display of polymer stabilized alignment type because it has the effect of improving the stability of the pretilt angle after optical crosslinking. The present invention has been completed.

Patent Document 1: Japanese Unexamined Patent Publication No. 10-513457 Patent Document 2: Japanese Unexamined Patent Publication No. 2005-60373 Patent Document 3: Japanese Unexamined Patent Publication No. 2001-527570 Patent Document 4: Korea Patent Publication No. 2011-0104416 Patent Document 5: Korea Patent Publication No. 2011-0094944 Patent Document 6: Republic of Korea Patent Publication No. 2009-0014375 Patent Document 7: Republic of Korea Patent Publication No. 2010-0848116

An object of the present invention is to provide a polymerizable mesogenic compound having improved photoreaction efficiency.

Moreover, the objective of this invention is providing the polymeric liquid crystal composition containing the said compound.

Furthermore, it is an object of the present invention to provide a polymer stabilized alignment liquid crystal display having a liquid crystal layer containing the polymerizable liquid crystal composition.

In order to achieve the above object,

The present invention provides a polymerizable mesogenic compound represented by Formula 1 below:

[Chemical Formula 1]

(In the formula 1,

A and X are as described herein).

In addition, the present invention provides a polymerizable liquid crystal composition comprising a polymerizable mesogen compound represented by Chemical Formula 1.

Furthermore, the polymer stabilized orientation liquid crystal display provided with the liquid crystal layer containing the said polymeric liquid crystal composition of this invention is provided.

The polymerizable mesogenic compound of the present invention has improved photoreaction efficiency at relatively low energy by introducing methoxyacrylate as a photoreactive group, and has a good solubility with a host liquid crystal due to the asymmetric structure, as well as the pretilt angle after photocrosslinking. Since there is an effect of improving the stability of the polymerizable liquid crystal composition, in particular, it can be usefully used as the polymerizable liquid crystal composition for liquid crystal display of the polymer stabilized alignment type.

Figure 1 is a graph showing the results of calculating the degree of photocuring for the compound of Example 6 and Comparative Example 1, in order to confirm the excellent photoreaction efficiency of the polymerizable mesogen introduced methoxyacrylate group of the present invention to be.

Hereinafter, the present invention will be described in detail.

The present invention provides a polymerizable mesogenic compound represented by Formula 1 below:

[Chemical Formula 1]

In Formula 1,

X is O, NH or S;

,

,

또는

이며, A is

,

,

or

Lt;

In the A,

R is any one selected from H, -R ', -C (= 0) -R', -C (= 0) -Ar-O-R 'and -C (= 0) -Ar-NH-R';

R 'is a C ₁ -C ₂₀ straight or branched alkylene group;

Ar is a C ₅ -C ₃₀ monocyclic, bicyclic or tricyclic arylene group;

L ₁ , L ₂ , L ₃ , L ₄ , L ₅ , L ₆ , L ₇ , L ₈ , L ₉ and L ₁₀ are independently hydrogen, a halogen atom, a C ₁ -C ₄ straight or branched alkyl group and C Any one selected from the group consisting of ₁ -C ₄ straight or branched haloalkyl groups;

n is an integer of 1 to 3;

Preferably, in the polymerizable mesogen compound represented by Formula 1, R ′ is a C ₁ -C ₁₀ linear or branched alkylene group, and Ar is a C ₁ -C ₅ monocyclic arylene group.

More preferably, the polymerizable mesogenic compound represented by Chemical Formula 1 is any one of the compounds represented by Chemical Formulas 2-9:

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

[Formula 7]

[Formula 8]

[Chemical Formula 9]

In Formula 2-9,

X is the same as defined in the above formula (1).

In addition, the present invention as shown in Scheme 1,

There is provided a process for preparing the polymerizable mesogenic compound represented by Formula 1 comprising reacting a compound of Formula 10 with a compound of Formula 11 under an organic solvent, a condensation reagent, and a base catalyst to produce a compound of Formula 1:

[Reaction Scheme 1]

In Scheme 1,

X and A are as defined in the above formula (1).

Specifically, in the method for producing a polymerizable mesogenic compound represented by Chemical Formula 1 of the present invention, the reaction of the compounds of Chemical Formula 10 and Chemical Formula 11 may be performed under a conventional organic solvent. The organic solvent may be selected and used without limitation as long as it is an organic solvent capable of dissolving each reactant well, and may be used alone or in combination. Preferably, dichloromethane may be used.

In addition, in the method for preparing a polymerizable mesogen compound represented by Chemical Formula 1 of the present invention, the reaction of the compound of Chemical Formula 10 and the compound of Chemical Formula 11 is a condensation reaction for removing water from two molecules, and is performed under a condensation reagent. Can be. The condensation reagent is preferably, but not limited to, ethylene dichloride (EDC) or dicyclohexylcarbodiimide (DCC).

Furthermore, in the method for producing the polymerizable mesogen compound represented by Chemical Formula 1 of the present invention, a catalyst may be further added as needed to improve the reaction activity or improve the reaction rate. The catalyst may be any conventional catalyst as long as it is capable of improving reaction activity or reaction rate. In order to obtain the product in high yield, a transition metal catalyst, an amine catalyst or a mixture thereof may be preferably used, and more preferably, N-hydroxybenzotriazole (HOBt) or dimethylaminopyridine (DMAP) may be used. have. The obtained product can be adjusted by removing impurities by the conventional purification method, preferably chromatographic method.

In addition, the present invention provides a polymerizable liquid crystal composition comprising a polymerizable mesogen compound represented by Chemical Formula 1.

Furthermore, this invention provides the polymer stabilized orientation liquid crystal display provided with the liquid crystal layer containing the said polymeric liquid crystal composition. Preferably the liquid crystal display is a vertical alignment type (VA-MODE) liquid crystal display.

Referring to Experimental Example 1, it can be seen that the polymerizable mesogen compound introduced with the methoxyacrylate group as the photoreactive group represented by the general formula (1) of the present invention has excellent solubility with the host liquid crystal in the vertical alignment type. In order to control the inclination of the liquid crystal, the liquid crystal display of the polymer stabilization orientation type is a system in which a mesogen compound polymerizable by ultraviolet rays is mixed with a host liquid crystal in a liquid crystal cell. Therefore, The mesogen compound can be usefully used as a polymerizable liquid crystal composition for a liquid crystal display of a polymer stabilization orientation type.

Referring to Experimental Example 2, the polymerizable mesogen compound in which the methoxyacrylate group is introduced into the photoreactive group represented by the general formula (1) of the present invention has high photoreaction efficiency and thus lowers voltage retention and long-term reliability due to remaining unreacted monomers. It does not limit the host liquid crystal and reactive mesogen structure design due to high energy since it can overcome the problem of and does not require a large exposure dose for polymerization. Therefore, the polymerizable mesogenic compound of the present invention can be usefully used as the polymerizable liquid crystal composition of the polymer stabilized alignment liquid crystal display.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following Examples and Experimental Examples.

< Example  1> 4,4`- Bis (alphamethoxyacryloyloxy) biphenyl  synthesis

Alphamethoxyacrylic  Acid synthesis

Methyl-2,2-dimethoxypropionate (25 g, 0.16 mol) and 0.5 g of p -toluenesulfonic acid monohydrate are refluxed at 140 ^° C. After 2 hours the temperature is raised to 190 ^° C. to obtain the remainder except methanol (14.5 g, 74%). 14.5 g of 2-methoxyacrylate was diluted in 120 ml of methanol and 12 ml of water, and 8.5 g of potassium hydroxide was added to reflux for 6 hours. Lower the temperature to 0 ^o C and adjust the pH to 2-3 with 10% hydrochloric acid. After 30 minutes, the mixture was extracted with ethyl acetate and water to obtain a yellow oil compound, alphamethoxyacrylic acid (10 g, 78%). :

¹ H NMR (CDCl ₃ , 300 MHz) 10.42 (s, 1H, COOH), 5.49-5.48 (d, 1H, CH ₂ ), 4.74-4.73 (s, 1H, CH ₂ ), 3.66 (s, 3H, OCH ₃ ); MS m / z 102 (M ⁺ )

4,4 ' Bis (alphamethoxyacryloyloxy) biphenyl  synthesis

200 ml of dichloromethane with 4,4'-dihydroxybiphenyl (3 g, 16.1 mmol), 1-hydroxybenzotriazole (9.6 g, 70.9 mmol) and alphamethoxyacrylic acid (7.7 g, 64.4 mmol) And diluted with 22 ml of triethylamine and stirred. After 20 minutes EDC (8.6 g, 70.9 mmol) is added dropwise. After 24 hours the byproducts are removed with dichloromethane and brine. Separation by column chromatography (hexane / ethyl acetate = 3/1) gave a white solid, 4,4′-bis (alphamethoxyacryloyloxy) biphenyl (0.5 g, 9%):

¹ H NMR (CDCl ₃ , 300 MHz) δ 7.60-7.55 (m, 2H, ArH), 7.23-7.19 (m, 2H, ArH), 5.60-5.59 (m, 1H, = CH ₂ ), 4.82-4.81 (m , 1H, = CH ₂ ), 3.74 (s, 3H, OCH ₃ ); MS m / z 354 (M ⁺ )

< Example  2> 4,4``- Bis (alphamethoxyacryloyloxy) terphenyl  synthesis

4,4``- Dimethoxydaphthalene  synthesis

Dibromobenzene (1.0 g, 4.2 mmol) dissolved in xylene (120 ml), followed by 1.6 g (10.5 mmol) of methoxyphenylboronic acid dissolved in 2 M aqueous potassium carbonate solution (5.3 ml) and 17 ml of ethanol. Put in order and after 30 minutes Pd (PPh ₃ ) ₄ (0.97g, 4.4 mmol) was added to raise the temperature to 100 ^o C and stirred for 24 hours. The reaction mixture lowered to room temperature was poured into excess water to terminate the reaction. After filtration, the solid was washed three times with distilled water, dichloromethane and methanol and dried to give a white solid, 4,4``-dimethoxyterphenyl (0.9 g, 75%) was obtained:

1 H NMR (300 MHz, DMSO- d 6)? 7.68 (4H, s), 7.67 (4H, d), 7.05 (4H, d), 3.80 (6H, s); MS (EI) m / z = 290.1 (M &lt; + &gt;).

4,4``- Dihydroxydaphthalene  synthesis

Dissolve 4,4`-dimethoxyterphenyl (1.0 g, 3.4 mmol) in dichloromethane (50 ml), lower the temperature to -78 ° C and then add BBr ₃ (Boron tribromide) (1.7 ml, 17.2 mmol) to 10 After dilution in ml of dichloromethane was added dropwise. Then, the reaction temperature was raised to room temperature and stirred for 10 hours. The reaction mixture was poured into excess water to terminate the reaction. After filtration, the solid was washed three times with distilled water and dichloromethane and dried to give a white solid, 4,4``-dihydroxyterphenyl (0.7 g, 79%). Got:

1 H NMR (300 MHz, CD 3 OD + DMSO-d 6)? 7.57 (4H, s), 7.50 (4H, d), 6.86 (4H, d); MS (EI) m / z = 262.1 (M &lt; + &gt;).

4,4``- Of bis (alphamethoxyacryloyloxy) terphenyl  synthesis

4,4′-dihydroxyterphenyl (3 g, 11.4 mmol), 1-hydroxybenzotriazole (6.8 g, 50.3 mmol) and alphamethoxyacrylic acid (5.5 g, 45.8 mmol) were converted to dichloromethane 200 Dilute in 22 ml of triethylamine and stir. After 20 minutes, EDC (9.7 g, 50.3 mmol) is added dropwise. After 24 hours, the by-products are removed with dichloromethane and brine. Separated by column chromatography (hexane / ethyl acetate = 3/1, dichloromethane / methanol = 15/1) to give a white solid, 4,4 ''-bis (alphamethoxyacryloyloxy) terphenyl (0.49 g, 10%) was obtained:

1 H NMR (300 MHz, DMSO-d6) δ 7.68 (4H, s), 7.67 (4H, d), 7.05 (4H, d), 5.63-5.62 (d, 2H, = CH ₂ ), 4.84-4.83 (d , 2H, = CH ₂ ), 3.76 (s, 6H, OCH ₃ ); MS (EI) m / z = 430 (M &lt; + &gt;).

< Example  3> 2,6- Bis (alphamethoxyacryloyloxy) naphthalene  synthesis

2,6-naphthalenediol (1 g, 6.2 mmol), 4- (dimethylamino) pyridine (3.4 g, 27.5 mmol) and alphamethoxyacrylic acid (1.9 g, 18.7 mmol) were added with 100 ml of dichloromethane and DMF 20 Dilute in ml and stir. After 20 minutes, DCC (5.7 g, 27.5 mmol) is added dropwise. After 24 hours, the byproduct is filtered off and the solvent is removed. Separated by silica gel column in hexane / ethyl acetate = 3/1 to give a white solid, 2,6-bis (alphamethoxyacryloyloxy) naphthalene (0.56 g, Yield 27%):

¹ H NMR (CDCl ₃ , 300 MHz) δ = 7.85-7.82 (d, 2H, ArH), 7.64-7.63 (m, 2H, ArH), 7.32-7.29 (dd, 2H, ArH), 5.63-5.62 (d, 2H, = CH ₂ ), 4.84-4.83 (d, 2H, = CH ₂ ), 3.76 (s, 3H, OCH ₃ ); MS m / z 328 (M ⁺ )

< Example  4> 2,5-bis (4- Alphamethoxyacryloyloxyphenyl Thiophene synthesis

2,5- Of bis (4-methoxyphenyl) thiophene  synthesis

Dibromothiophene (5.3 g, 21.9 mmol) was dissolved in xylene (120 ml) and then 10.0 g (65.7 mmol) of methoxyphenyl bronic acid dissolved in 2 MK ₂ CO ₃ (25 ml) and 80 ml ethanol. After degassing for 30 minutes, 45.1g (4.4mmol) of Pd (PPh3) was added thereto, and the temperature was raised to 100 ° C and stirred for 24 hours. The reaction mixture was cooled to room temperature and poured into excess water to terminate the reaction. After filtration, the solid was washed three times with distilled water, dichloromethane and ethanol, and dried to give a pale yellow green solid, 2,5-bis (4-methoxyphenyl). Thiophene (6.0 g, 93%) was obtained:

D), 7.36 (2H, s), 7.01 (4H, d), 3.79 (6H, s); MS (EI) m / z = 296.1 (M &lt; + &gt;).

2,5- Of bis (4-hydroxyphenyl) thiophene  synthesis

Dissolve 2,5-bis (4-methoxyphenyl) thiophene (6.0 g, 20.3 mmol) in dichloromethane (200 ml), lower the temperature to -78 ° C, and 30 ml of BBr3 (9.8 ml, 101.3 mmol). It was added dropwise after dilution with dichloromethane. The reaction temperature was then raised to room temperature and stirred for 10 hours. The reaction mixture was poured into excess water to terminate the reaction. After filtration, the solid was washed several times with dichloromethane and dried to obtain brown solid, 2,5-bis (4-hydroxyphenyl) thiophene (5.1 g, 94%). Got:

1 H NMR (300 MHz, CD 3 OD + DMSO-d 6)? 7.40 (4H, d), 7.08 (2H, s), 6.75 (4H, d); MS (EI) m / z = 268.5 (M &lt; + &gt;).

2,5-bis [(4- (2- Methoxyacryloyl ) Phenyl )] Thiophene  synthesis

4,4 '-(thiophene-2,5-diyl) diphenol (1.5 g, 5.6 mmol), 4- (dimethylamino) pyridine (3.0 g, 24.6 mmol) and alphamethoxyacrylic acid (2.3 g, 22.4 mmol) is diluted in 100 ml of dichloromethane and 20 ml of DMF and stirred. After 20 minutes, DCC (5.0 g, 24.6 mmol) is added dropwise. After 24 hours, filter the by-product and remove the solvent. Hexane / ethyl acetate = 3/1 separated by silica gel column to give a white solid, 2,5-bis [(4- (2-methoxyacryloyl) phenyl)] thiophene (0.1 g, 4%) :

¹ H NMR (Acetone-d ₆ , 300 MHz) δ = 7.77-7.74 (m, 2H, ArH), 7.56 (s, 1H, ArH), 7.29-7.26 (m, 2H, ArH), 5.51-5.50 (d, 1H, = CH ₂ ), 5.02-5.01 (d, 1H, = CH ₂ ), 3.68 (s, 3H, OCH ₃ ); MS m / z 436 (M ⁺ )

< Example  5 > 2- (4- Alphamethoxyacryloyloxyphenyl ) -7- Alphamethoxyacryloyloxy Carbazole  synthesis

2- (4-hydroxyphenyl) -7-hydroxycarbazole (crude 2 g, 7.2 mmol), 4- (dimethylamino) pyridine (3.9 g, 31.6 mmol) and alphamethoxyacrylic acid (2.2 g, 21.8 mmol) is diluted in 100 ml of dichloromethane and 20 ml of DMF and stirred. After 20 minutes, DCC (6.6 g, 31.6 mmol) is added dropwise. After 24 hours, the byproduct is filtered off and the solvent is removed. Separated by silica gel column in hexane / ethyl acetate = 3/1, white solid, 2- (4-alphamethoxyacryloyloxyphenyl) -7-alphamethoxyacryloyloxy carbazole (0.8 g) was obtained. :

¹ H NMR (Acetone-d ₆ , 300 MHz) δ = 8.03-7.95 (q, 2H, ArH), 7.66-7.62 (m, 3H, ArH), 7.41-7.38 (dd, 1H, ArH), 7.04-7.01 ( m, 3H, ArH), 6.82-6.79 (dd, 1H, ArH), 5.63-5.62 (d, 2H, = CH ₂ ), 4.84-4.83 (d, 2H, = CH ₂ ), 3.76 (s, 6H, OCH ₃ ); MS m / z 443 (M ⁺ )

In addition, in order to compare and evaluate the improved photoreactivity of the polymerizable mesogen in which the methoxyacrylate group is introduced into the photoreactive group of the present invention, Example 6 having methoxyacrylate as the photoreactive group and the methacrylate group as the photoreactive group The compound of Comparative Example 1 having was synthesized.

< Example  6> 1,6- Bis (2-methoxyacryloyloxy) hexane  ( HX - aMA ) synthesis

1,6-hexanediol (1 g, 8.5 mmol), 4- (dimethylamino) pyridine (4.5 g, 37.2 mmol) and alphamethoxyacrylic acid (3.5 g, 33.8 mmol) were diluted with 100 ml of dichloromethane and DMF 20 Dilute in ml and stir. After 20 minutes, DCC (7.6 g, 37.2 mmol) is added dropwise. After 24 hours, filter the by-product and remove the solvent. White solid, 1,6-bis (2-methoxyacryloyloxy) hexane (1.3 g, 54%), separated by silica gel column in hexane / ethyl acetate = 3/1, dichloromethane / methanol = 15/1 Got:

¹ H NMR (CDCl ₃ , 300 MHz) δ = 5.34-5.33 (d, 1H, = CH ₂ ), 4.62-4.61 (d, 1H, = CH ₂ ), 4.23-4.18 (t, 2H, OCH ₂ ), 3.65 (s, 3H, OCH ₃ ), 1.73-1.69 (m, 2H, CH ₂ ), 1.44-1.39 (m, 2H, CH ₂ ); MS m / z 286 (M ⁺ )

< Comparative Example  1> 1,6- Bis (methacryloyloxy) hexane  ( HX - MA ) synthesis

Dissolve methacrylic acid (5.7 g, 67.7 mmol) in dichloromethane (300 ml), add 2-3 drops of DMF, lower the temperature to 0 ° C and slowly add oxalyl chloride (6.0 ml, 67.7 mmol) Methacryloyl chloride was prepared by raising the temperature to room temperature.

To another reactor, 1,6-hexanediol (2.0 g, 16.9 mmol) was dissolved in dichloromethane (100 ml), TEA (23.6 ml, 169.2 mmol) and DMAP (0.2 g, 1.7 mmol) The mixture was stirred at room temperature for 3 hours. The reaction mixture was poured into excess distilled water to terminate the reaction, extracted with dichloromethane, separated by column chromatography (hexane: ethyl acetate = 50: 1 solvent) to obtain a liquid, 1,6-bis (methacryloyloxy). ) Hexane (1.7 g, 39.5%) was obtained:

^{1 H NMR (300 MHz, CDCl} 3) δ 6.09 (2H, m), 5.55 (2H, m), 4.16 (4H, t), 1.94 (6H, m), 1.71 (4H, quint), 1.45 (4H, m).

< Experimental Example  1> Solubility evaluation with host liquid crystal

In order to confirm the high solubility of the polymerizable mesogen compound in which the methoxyacrylate group is introduced into the photoreactive group of the present invention with the host liquid crystal, the solubility of the polymerizable mesogen compound of Examples 1 to 5 with the host liquid crystal It was evaluated, and the results are shown in Table 1 below.

In order to evaluate the solubility of the polymerizable mesogen compound of Examples 1-5 with the host liquid crystal, 0.5 wt.% Of the polymerizable mesogen compound of Examples 1-5 was added to the liquid crystal for vertical alignment (MLC-6608, Merck). The mixture was stirred and observed visually after 1 hour. In addition, changes were observed after standing at −30 ° C. for 3 days to evaluate stability at low temperatures. The observed solubility of the polymerizable mesogen compound of Examples 1-5 with the host liquid crystal was very well melted (-), slightly melted upon heating- (O) and not melted- (X).

division Room temperature -30 ° C Example 1 ◎ ◎ Example 2 ◎ ◎ Example 3 ◎ ◎ Example 4 ◎ ◎ Example 5 O O

As a result, as shown in Table 1 above, the polymerizable mesogen compound having the carbazole of Example 5 as a core at room temperature and -30 ° C can be dissolved in the host liquid crystal due to slight heating, and Examples 1-4. The polymerizable mesogenic compounds each having a biphenyl, terphenyl, naphthalene and dithiophene core can be dissolved very well in the host liquid crystal without heating.

From this, it can be seen that the polymerizable mesogenic compounds of Examples 1 to 5 of the present invention have excellent solubility in the vertically aligned host liquid crystal due to the asymmetric structure.

Therefore, the polymerizable mesogenic compound which introduce | transduced the methoxyacrylate group into the photoreactive group of this invention mixes the mesogenic compound which can superpose | polymerize with an ultraviolet-ray together with a host liquid crystal, and controls the inclination of a host liquid crystal type liquid crystal display. It can be usefully used as the polymerizable liquid crystal composition for.

< Experimental Example  2> FT - IR Using Photoreactive  evaluation

In order to comparatively evaluate the improved photoreaction efficiency of the polymerizable mesogenic compound in which the methoxyacrylate group is introduced into the photoreactive group of the present invention, the compound of Example 6 and Comparative Example 1 having a methacrylate group as the photoreactive group, FT Photoreactivity evaluation was performed using -IR, and the results are shown in Table 2 and FIG. 1.

The compounds of Example 6 and Comparative Example 1 were dissolved in 1,2-dichloroethane at 10 wt.%, Respectively, coated on KBr pellets, irradiated with UV (365 nm) from 1 to 50 J, FT-IR spectrum was obtained. The degree of photocuring was calculated from the area ratio of C = O band and C = C band in the obtained spectrum.

division 0J 1J 2J 3J 5J 10J 20J 30J 50J Example 6
Photocuring degree (%) 0 9 12 18 29 42 43 49 54 Comparative Example 1
Photocuring degree (%) 0 10 14 14 16 17 16 18 18

As a result, as shown in Table 2 and Figure 1, the polymerizable mesogen compound of Example 6 of the present invention, as the ultraviolet irradiation energy increases, the degree of light curing up to 10 J ultraviolet irradiation energy significantly increased, 50 A maximum of 54% photocuring at the ultraviolet irradiation energy of J. On the other hand, the compound having a methacrylate as a photoreactive group of Comparative Example 1, although the degree of photocuring increases as the ultraviolet irradiation energy increases, the rise is insignificant, showing a maximum degree of photocuring of 18%.

From this, it can be seen that the polymerizable mesogen introduced with methoxyacrylate as the photoreactive group of Example 6 of the present invention has better photoreactivity than the compound into which the methacrylate known as the conventional photoreactive group of Comparative Example 1 is introduced. .

Since the polymerizable mesogen in which the methoxyacrylate group of the present invention is introduced has a high photoreaction efficiency even at a relatively low energy, the voltage retention rate is lowered due to the unreacted monomer, which is a problem of the polymerizable mesogen used in the conventional polymer stabilized alignment type. And the problem of long-term reliability, and does not require a large exposure dose for the polymerization, and does not limit the structural design of the host liquid crystal and the reactive mesogen due to the high energy. Therefore, the polymerizable compound having the methoxyacrylate group introduced thereinto of the present invention can be usefully used as a polymerizable liquid crystal composition for a liquid crystal display of a polymer stabilization orientation type.

Claims (10)

A polymerizable mesogenic compound represented by the following general formula (1):
[Chemical Formula 1]

(In the formula 1,
X is O, NH or S;
A is

,

,

or

Lt;
In the A,
R is H;
L ₁ , L ₂ , L ₃ , L ₄ , L ₅ , L ₆ , L ₇ , L ₈ , L ₉ and L ₁₀ are independently hydrogen, a halogen atom, a C ₁ -C ₄ straight or branched alkyl group and C Any one selected from the group consisting of ₁ -C ₄ straight or branched haloalkyl groups;
and n is an integer of 1 to 3).
The method of claim 1,
L ₁ , L ₂ , L ₃ , L ₄ , L ₅ , L ₆ , L ₇ , L ₈ , L ₉ and L ₁₀ are independently selected from the group consisting of -H, -F, -CH ₃ and -CF ₃ It is any one of which is a polymeric mesogenic compound.
The method of claim 1,
The polymerizable mesogen compound represented by the formula (1) is any one selected from the group consisting of compounds represented by the following formulas (2-9):
(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

[Chemical Formula 9]

(2 to 9)
X is as defined in claim 1).
As shown in Scheme 1 below,
Reacting a compound of Formula 10 with a compound of Formula 11 under an organic solvent, a condensation reagent, and a base catalyst to prepare a compound of Formula 1,
The condensation reagent is ethylene dichloride (EDC) or dicyclohexylcarbodiimide (DCC) method for producing a polymerizable mesogen compound represented by Formula 1, characterized in that:
[Reaction Scheme 1]

(In the above Reaction Scheme 1,
X and A are as defined in claim 1).
5. The method of claim 4,
The organic solvent is a method for producing a polymerizable mesogen compound, characterized in that dichloromethane.
delete 5. The method of claim 4,
The base catalyst is hydroxybenzotriazole (HOBt) or dimethylaminopyridine (DMAP) method for producing a polymerizable mesogen compound, characterized in that.
A polymerizable liquid crystal composition comprising a polymerizable mesogen represented by the following formula
[Chemical Formula 1]

(In the formula 1,
X and A are as defined in claim 1).
A polymer-stabilized alignment liquid crystal display comprising a liquid crystal layer comprising the polymerizable liquid crystal composition of claim 8.
10. The method of claim 9,
And said liquid crystal display is a liquid crystal display of vertical alignment type (VA-MODE).

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