KR102391230B1 - A reactive mesogen composition, a polarizer and a display device comprising the same - Google Patents

Abstract

A display device according to an embodiment of the present invention includes a thin film transistor array substrate having a pixel electrode and a common electrode, a color filter array substrate facing the thin film transistor array substrate and including a color filter, the thin film transistor array substrate and a color filter A liquid crystal layer interposed between the array substrates, and a polarizing plate provided on at least one surface of the thin film transistor array substrate and the color filter array substrate, wherein the polarizing plate includes the reactive mesogen compound.

Description

Reactive mesogen compound, polarizing plate and display including the same

The present invention relates to a reactive mesogen compound, and more particularly, to a reactive mesogen compound in which a dye and a reactive mesogen are synthesized, a polarizing plate and a display device including the same.

In general, a liquid crystal display (LCD) has a wide range of applications due to its features such as light weight, thin shape, low power operation, full color, and high resolution. Currently, liquid crystal displays are used in computers, notebook computers, PDAs, telephones, TVs, audio/video devices, and the like. On the other hand, two polarizing plates are used in the liquid crystal display device, and the polarizing plates have a function of turning incident natural light vibrating in several directions into light vibrating only in one direction, that is, polarized light. Accordingly, the light polarized by the lower polarizing plate is incident on the liquid crystal cell, and the light passing through the liquid crystal layer is polarized by the upper polarizing plate to display an image.

A polarizing plate is manufactured by stretching a polyvinyl alcohol (PVA) film, dyeing it with iodine (I2) or a dichroic dye, crosslinking using boric acid, and stretching and drying the PVA film. After attaching the TAC to both sides of the manufactured polarizer through an adhesive, it is adhered to the liquid crystal panel. However, the conventional polarizing plate has a problem in that the thickness of the polarizing plate is thick, the heat resistance and moisture resistance of the polarizing plate are low, and the process time is long and the manufacturing cost is increased due to the execution of the stretching process and the dyeing process for the PVA polarizer.

Recently, a coating-type polarizing plate for manufacturing a polarizing plate by a coating method has been developed. The coating-type polarizing plate mixes the guest R, G, and B dyes with the liquid crystal, which is the host, and when the host is aligned according to the alignment direction of the lower alignment layer, the R, G, and B dyes are arranged together so that the dye alignment direction (absorption direction) There is a host/guest type polarizing plate that polarizes light by absorbing light parallel to it and transmitting light perpendicular to it.

However, since the host/guest type polarizing plate has a difference in the alignment directions of the host liquid crystal and the guest dye, it acts as a factor to degrade the performance of the polarizing plate. In addition, it is difficult to control the β angle between the easy axis of the liquid crystal and the direction of the dye, so there is a problem in that the alignment of the liquid crystal is lowered and the degree of polarization is lowered.

The present invention provides a reactive mesogen compound in which a dye and a reactive mesogen are synthesized, and a polarizing plate and a display device including the same.

In order to achieve the above object, the reactive mesogenic compound according to an embodiment of the present invention is characterized in that it is represented by the following formula (1).

[Formula 1]

,

,

또는

중 선택된 어느 하나이며, E₁ 내지 E₄는 각각 독립적으로 수소, -OH, -OCH₃, -SO₃Na, -CH₃, -NH₂ 또는 -NHCOCH₃ 중 선택된 어느 하나이고, 상기 B는

,

,

또는

중 선택된 어느 하나이고, 상기 C₁ 및 C₂는 각각 독립적으로

또는

이며, E₁ 내지 E₄는 각각 독립적으로 수소, -OH, -OCH₃, -SO₃Na, -CH₃, -NH₂ 또는 -NHCOCH₃ 중 선택된 어느 하나이고, 상기 X는

,

,

,

또는

중 선택된 어느 하나이다.In Formula 1, R is H or CH ₃ , n is 0 to 12, and A is

,

,

or

Any one selected from, E ₁ to E ₄ are each independently hydrogen, -OH, -OCH ₃ , -SO ₃ Na, -CH ₃ , -NH ₂ or -NHCOCH ₃ Any one selected from, wherein B is

,

,

or

any one selected from, wherein C ₁ and C ₂ are each independently

or

and E ₁ to E ₄ are each independently hydrogen, -OH, -OCH ₃ , -SO ₃ Na, -CH ₃ , -NH ₂ or -NHCOCH ₃ Any one selected from, wherein X is

,

,

,

or

any one selected from

The reactive mesogenic compound represented by Formula 1 is characterized in that it is any one of the compounds represented below.

In addition, the polarizing plate according to an embodiment of the present invention is characterized in that it includes a polarizing layer including the reactive mesogen compound.

The reactive mesogenic compound is characterized in that it is coated in a liquid phase.

In addition, a display device according to an embodiment of the present invention includes a thin film transistor array substrate having a pixel electrode and a common electrode, a color filter array substrate facing the thin film transistor array substrate and including a color filter, the thin film transistor array substrate and A liquid crystal layer interposed between the color filter array substrates, and a polarizing plate provided on at least one surface of the thin film transistor array substrate and the color filter array substrate, wherein the polarizing plate includes the reactive mesogen compound.

In the present invention, by synthesizing a dye in the reactive liquid crystal to form a reactive liquid crystal compound, the conventional process of mixing the reactive liquid crystal and the dye can be omitted. In addition, by synthesizing a reactive liquid crystal and a dye to form a single compound, it is possible to solve the difficulty in controlling the β angle because the conventional reactive liquid crystal and the dye are mixed, and there is an advantage in that the alignment of the reactive liquid crystal and the dye can be improved. .

1 is a cross-sectional view illustrating a display device according to an embodiment of the present invention;
Figure 2 is an NMR graph of (3) material prepared in the synthesis of compound 3.
Figure 3 is an NMR graph of (4) material prepared in the synthesis of compound 3.
4 is an NMR graph of compound 3.
5 is a UV-vis spectrum graph of compound 3.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a polarizing plate using a reactive liquid crystal compound prepared by synthesizing a reactive mesogen and a dye.

As the reactive liquid crystal of the present invention, a liquid crystalline polymer or a liquid crystalline small molecule or oligomer having a photosensitive group showing optical anisotropy and a mesogen forming group showing liquid crystallinity in a specific temperature range as linearly polarized light is irradiated may be used, Mixtures thereof may also be used. The reactive liquid crystal consists of a polyacrylate-based main chain and one or a plurality of side chains connected to the main chain. Each side chain is provided with one or two aromatic substances and a photoreactant is provided as a terminal of the side chain, so that a photo-isomerization reaction or a photodimerization reaction occurs. In addition, a hydrogen bonder may be provided as a terminal. When the reactive liquid crystal is irradiated with linearly polarized light, a photo-isomerization reaction and a photo-dimerization reaction occur. When anisotropy occurs in the reactive liquid crystal, the optical anisotropy can be increased by heat treatment, so that the reactive liquid crystal can be arranged in a predetermined direction.

R, G, and B dyes are synthesized in the reactive liquid crystal. The dyes are arranged along the direction of the side chains of the reactive liquid crystal. That is, the dye is arranged perpendicular to the linear polarization direction of the irradiated light. When light is incident as the dye is arranged in a predetermined direction, a polarization component parallel to the arrangement direction of the dye, that is, the absorption direction is absorbed, and a polarization component perpendicular to the absorption direction is transmitted.

The reactive liquid crystal compound of the present invention described above is represented by the following formula (1).

[Formula 1]

,

,

또는

중 선택된 어느 하나이며, 여기서, E₁ 내지 E₄는 각각 독립적으로 수소, -OH, -OCH₃, -SO₃Na, -CH₃, -NH₂ 또는 -NHCOCH₃ 중 선택된 어느 하나이다. 또한, B는

,

,

또는

중 선택된 어느 하나이다. 또한, C₁ 및 C₂는 각각 독립적으로

또는

이며, E₁ 내지 E₄는 각각 독립적으로 수소, -OH, -OCH₃, -SO₃Na, -CH₃, -NH₂ 또는 -NHCOCH₃ 중 선택된 어느 하나이다. X는

,

,

,

또는

중 선택된 어느 하나이다.In Formula 1, R is H or CH ₃ , and n is 0 to 12. The A is

,

,

or

is any one selected from, wherein E ₁ to E ₄ are each independently selected from hydrogen, -OH, -OCH ₃ , -SO ₃ Na, -CH ₃ , -NH ₂ or -NHCOCH ₃ . Also, B is

,

,

or

any one selected from In addition, C ₁ and C ₂ are each independently

or

and E ₁ to E ₄ are each independently selected from hydrogen, -OH, -OCH ₃ , -SO ₃ Na, -CH ₃ , -NH ₂ or -NHCOCH ₃ . X is

,

,

,

or

any one selected from

In the reactive liquid crystal compound represented by Formula 1, A acts as a core of the reactive liquid crystal compound, maintains structural symmetry of the reactive liquid crystal compound, and maintains coplanarity of pi-electrons. B acts as an extender of the reactive liquid crystal compound, and extends the conjugate length of pi-electrons. C ₁ and C ₂ act as sub-cores of the reactive liquid crystal compound, extend the conjugate length of pi-electrons, and maintain planarity. In addition, C ₁ and C ₂ express mesogen properties of the reactive liquid crystal compound. X acts as a linker of the reactive compound, and acts as a linking point for the terminal acryl group. X affects the flexibility and liquid crystal transition temperature of the reactive compound.

Accordingly, the reactive liquid crystal compound represented by Formula 1 of the present invention may be any one of the following compounds.

In the present invention, by synthesizing a dye in the reactive liquid crystal to form a reactive liquid crystal compound, the conventional process of mixing the reactive liquid crystal and the dye can be omitted. In addition, by synthesizing the reactive liquid crystal and the dye to form a single compound, it is possible to solve the difficulty in controlling the β angle because the conventional reactive liquid crystal and the dye are mixed, and there is an advantage that the alignment of the reactive liquid crystal and the dye can be improved. .

A method of manufacturing a polarizing plate using the above-described reactive liquid crystal compound will be described as follows.

First, a reactive liquid crystal compound as a host and a dye as a guest are synthesized to prepare a reactive liquid crystal compound, and then the compound is applied on a substrate to form a polarizing layer. The reactive liquid crystal compound is formed by various liquid coating methods such as spin coating and slit coating. The polarizing layer is formed to a thickness of 1 to 5 μm, and other additives may be added. Then, the solvent is removed by drying the substrate on which the polarizing layer is formed at a temperature of 20 to 80° C. for several to several tens of minutes. As the polarizing layer is dried, the molecular arrangement of the reactive liquid crystal compound of the polarizing layer is prevented from being changed. The drying process may be performed by a hot plate or an oven, and may also be naturally dried.

Then, the dried polarization layer is irradiated with linearly polarized light. As light is irradiated, the reactive liquid crystal compound of the polarizing layer is aligned in a specific direction to form a light absorption side and a light transmission axis. The irradiated light uses a wavelength range of 200 to 400 nm and the energy is 1-1000 mJ/cm 2 . Then, the polarization layer irradiated with light is heat-treated to improve the polarization characteristics of the polarization layer. The heat treatment is performed at 80 to 150° C. so that liquid crystallinity is best exhibited. Accordingly, a polarizing plate using the reactive liquid crystal compound of the present invention is manufactured.

Hereinafter, a display device including the polarizing plate including the reactive liquid crystal compound of the present invention described above will be described.

1 is a cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1 , the display device 100 of the present invention includes a liquid crystal layer 180 interposed between a thin film transistor array substrate 110 and a color filter array substrate 190 .

A semiconductor layer 115 is positioned on the thin film transistor array substrate 110 , and a gate insulating film 120 covering and insulating the semiconductor layer 115 is positioned. A gate electrode 125 is positioned on the gate insulating layer 120 in a region corresponding to the semiconductor layer 115 . Also, a gate line (not shown) connected to the gate electrode 125 and extending in one direction is positioned on the gate insulating layer 120 . An interlayer insulating layer 130 is positioned on the gate electrode 125 to insulate the gate electrode 125 . The gate insulating layer 120 and the interlayer insulating layer 130 are formed of silicon oxide, silicon nitride, or a multilayer structure thereof. Contact holes 135a and 135b exposing both ends of the semiconductor layer 115 are provided in the interlayer insulating layer 130 and the gate insulating layer 120 .

A source electrode 140a and a drain electrode 140b are positioned on the interlayer insulating layer 130 and are respectively connected to both exposed sides of the semiconductor layer 115 through the contact holes 135a and 135b. Accordingly, a thin film transistor including the semiconductor layer 115 , the gate electrode 125 , the source electrode 140a , and the drain electrode 140b is configured. In the present invention, a top gate type thin film transistor in which a gate electrode is located on a semiconductor layer has been described as an example, but a bottom gate type thin film transistor in which a gate electrode is located under a semiconductor layer can also be applied. may be provided.

Meanwhile, a first passivation layer 145 is positioned on the thin film transistor array substrate 110 provided with the thin film transistor. The second passivation layer 150 is made of the same material as the gate insulating layer 120 or the interlayer insulating layer 130 described above. A second passivation layer 150 made of an organic insulating material, for example, photoacrylic or benzocyclobutene, is positioned on the first passivation layer 145 . A common electrode 160 made of a transparent conductive material is positioned on the second passivation layer 150 . A third passivation layer 165 is disposed on the common electrode 160 to insulate the common electrode 160 . The third passivation layer 165 and the second passivation layer 150 are provided with a via hole 155 exposing the drain electrode 135b of the thin film transistor. A pixel electrode 170 connected to the drain electrode 135b is positioned on the third passivation layer 165 . The pixel electrode 170 is provided with openings in the form of a plurality of bars to generate a fringe field together with the common electrode 160 when a driving voltage is applied. Accordingly, the thin film transistor array substrate 110 provided with the thin film transistor, the pixel electrode, and the common electrode is configured.

Meanwhile, the color filter array substrate 190 is positioned on the thin film transistor array substrate 110 . A black matrix 195 is provided on the inner surface of the color filter array substrate 190 to correspond to the boundary of each pixel and the thin film transistor, and a region partitioned by the black matrix 195 corresponds to each pixel. Red, green, and blue color filters 197 are positioned. The liquid crystal layer 180 is interposed between the thin film transistor array substrate 110 and the color filter array substrate 190 configured as described above. In addition, the upper polarizing plate 210 is positioned on the upper surface of the color filter array substrate 190 and the lower polarizing plate 220 is positioned on the lower surface of the thin film transistor array substrate 110 to constitute the display device 100 of the present invention.

A display device according to an embodiment of the present invention includes an upper polarizing plate 210 and a lower polarizing plate 220 on the upper surface of the color filter array substrate 190 and the lower surface of the thin film transistor array substrate 110 . Since the upper polarizing plate 210 and the lower polarizing plate 220 are formed of the above-described reactive liquid crystal compound, the existing process of mixing the reactive liquid crystal and the dye is omitted, and thus the process is easy. In addition, by synthesizing the reactive liquid crystal and the dye to form a single compound, the conventional reactive liquid crystal and the dye are mixed to solve the difficulty in controlling the β angle, and there is an advantage in that the alignment of the polarizing plate can be improved.

Hereinafter, synthetic examples of the reactive liquid crystal compound of the present invention and properties of the compound will be described in detail in the following examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited to the following examples.

Synthesis of compound 1

A mixture of 4,4'-diaminostilbene (4,4'-diaminostilbene) (3.53 mmol), 20 ml of water, and 1.47 ml of 37% hydrochloric acid (HCl) is heated to a complete solution. After cooling to 0 to 5 ℃, sodium nitrite (NaNO ₂ ) 7.06 mmol aqueous solution dissolved in water is slowly dropped into the previous solution and reacted for 2 hours. 6-((6-amino-5-hydroxynaphthalen-2-yl)oxy)hexyl methacrylate) (7.77 mmol) is dissolved in 200 ml of water and adjusted to pH 7. The prepared diazonium salt (diazonium salt) solution is added to the previous solution at 0 to 5° C., and the pH of the solution is maintained at 8 to 9. The solution is stirred for 2 hours, and a 3wt% solution of sodium chloride is added to the previous solution. The formed precipitate is washed with water, filtered, and dried in a vacuum oven. The material remaining after the filter (crude product) was put in ethanol and refluxed for 2 hours, and then washed with hot ethanol, filtered, and dried in a vacuum oven to obtain Compound 1. The yield is 69.5%.

Synthesis of compound 2

Ethyl-4-hydroxybenzoate (2 mmol), 6-chlorohexyl methacrylate (2.1 mmol), potassium carbonate (K ₂ CO ₃ ) (4.4 mmol) was put in DMF (30 ml) and refluxed for 12 hours. After lowering the temperature to room temperature, the solution is poured into cold water, the resulting precipitate is filtered, and recrystallized from ethanol. The yield is 47.6%.

Methyl-4-((6-(methacryloyloxy)hexyl)oxy)benzoate (Methyl-4-((6-(methacryloyloxy)hexyl)oxy)benzoate) (0.05 mmol), 20 cm 3 ionic liquid liquid) into a three-necked flask and refluxed at 140°C for 3 hours. 30 ㎤ anhydrous diethyl ether is added to the reaction mixture lowered to room temperature. The organic layer is separated and dried with sodium sulfate (Na ₂ SO ₄ ). The solvent is evaporated from the crude product remaining after the filter. The produced material is obtained by recrystallization from ethanol (ethanol). The yield is 67.1%.

Prepare a 500 ml round flask and a drying tube connected to a balloon filled with nitrogen. In a flask, add DDC (34.8 mmol), DMAP (34.8 mmol), MC (270ml), (E)-4,4'-(diazene-1,2-diyl)diphenol (34.8 mmol), 6-chloro-1-hexanol (34.8 mmol) was added and stirred at room temperature for 24 hours. White solid particles are produced. The mixture was filtered, and the solution was purified by column chromatography to obtain compound 2. The yield is 44.2%.

Synthesis of compound 3

To a solution of 1,4-benzenediamine (4.623 mmol) (1) in 10 ml of distilled water, slowly drop hydrochloric acid (HCl) (12 mol/L) at a reaction temperature of 0°C. Then, a solution of sodium nitrite (NaNO ₂ ) (10.16 mmol) in 12 ml of distilled water is also slowly dropped. The reaction temperature is maintained at 0 to 5 °C. After stirring for 40 minutes, a benzidine diazonium chloride solution (2) is obtained. Phenol (9.246 mmol), sodium hydroxide (NaOH) (9.246 mmol), ethanol (ethanol) (20 ml) in a mixed solution (2) is slowly dropped at a reaction temperature of 0 to 5 ℃. The mixed solution is stirred until a brown precipitate is formed, and then the brown precipitate is washed with distilled water and filtered. Recrystallization produces the result of (3) after purification. The yield is 40.6%.

DCC (34.8 mmol), DMAP (34.8 mmol), 1,2-Dichromethane (270 ml), methacrylic acid (34.8 mmol), 6-chloro-1-hexane Add 6-chloro-1-hexanol (34.8 mmol) and react at room temperature for 24 hours. White solid particles are formed, and after the reaction is completed, it is filtered. The obtained solution is purified using column chromatography. MC is used as the developing solution. The yield is 59.6% (4).

The obtained material (3) (0.2 mmol), (4) material (0.42 mmol), potassium carbonate (K ₂ CO ₃ ) (0.84 mmol), and DMF (10 ml) were added and refluxed for 3 hours. The obtained solution was cooled with cold distilled water, and the solid obtained at this time was recrystallized from ethanol after filtering to obtain Compound 3. The yield is 2%.

2 is an NMR graph of (3) material prepared in the synthesis of compound 3, FIG. 3 is an NMR graph of (4) material prepared in the synthesis of compound 3, FIG. 4 is an NMR graph of compound 3, FIG. 5 is a UV-vis spectrum graph of compound 3.

2 to 4, it was confirmed through the NMR graph of FIG. 2 that the material (3) was prepared, and it was confirmed through the NMR graph of FIG. 3 that the material (4) was prepared, and through the NMR graph of FIG. It was confirmed that compound 3 was prepared. In addition, referring to FIG. 5 , it could be confirmed that the maximum wavelength of compound 3 was 396 nm through the UV-vis spectrum graph of compound 3.

Through the above results, it can be confirmed that compound 3 was actually synthesized, and it can be confirmed that the maximum wavelength of compound 3 is 396 nm.

As described above, the reactive liquid crystal compound, the polarizing plate, and the display device including the same according to an embodiment of the present invention has an advantage in that it is easy to process by omitting the conventional process of mixing the reactive liquid crystal and the dye. In addition, by synthesizing the reactive liquid crystal and the dye to form a single compound, the conventional reactive liquid crystal and the dye are mixed to solve the difficulty in controlling the β angle, and there is an advantage in that the alignment of the polarizing plate can be improved.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention can be changed to other specific forms by those skilled in the art to which the present invention pertains without changing the technical spirit or essential features of the present invention. It will be appreciated that this may be practiced. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. In addition, the scope of the present invention is indicated by the claims to be described later rather than the above detailed description. In addition, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

100: display device 110: thin film transistor array substrate
190: color filter array substrate
210: upper polarizing plate 220: lower polarizing plate

Claims (8)

A reactive mesogenic compound, characterized in that it is represented by the following formula (1).
[Formula 1]

In Formula 1,
R is H or CH ₃ , n is 0 to 12,
The A is

,

,

or

Any one selected from, E ₁ to E ₄ are each independently hydrogen, -OH, -OCH ₃ , -SO ₃ Na, -CH ₃ , -NH ₂ or -NHCOCH ₃ Any one selected from,
The B is

,

,

or

Any one selected from
The C ₁ and C ₂ are each independently

or

and E ₁ to E ₄ are each independently hydrogen, -OH, -OCH ₃ , -SO ₃ Na, -CH ₃ , -NH ₂ or -NHCOCH ₃ Any one selected from,
wherein X is

,

,

,

or

any one selected from
According to claim 1,
The reactive mesogenic compound represented by Formula 1 is a reactive mesogenic compound, characterized in that it is any one of the compounds represented below.

A polarizing plate comprising a polarizing layer comprising the reactive mesogenic compound according to claim 1 or 2.
4. The method of claim 3,
The reactive mesogen compound is a polarizing plate, characterized in that it is coated in a liquid phase.
a thin film transistor array substrate having a pixel electrode and a common electrode;
a color filter array substrate facing the thin film transistor array substrate and including a color filter;
a liquid crystal layer interposed between the thin film transistor array substrate and the color filter array substrate; and
and a polarizing plate provided on at least one surface of the thin film transistor array substrate and the color filter array substrate,
The polarizing plate is a display device comprising the reactive mesogenic compound according to claim 1 or 2 . A reactive mesogenic compound represented by the following formula.
[Formula]

In the above formula, R is H or CH ₃ and n is an integer of 0 to 12.
A polarizing plate comprising a polarizing layer comprising the reactive mesogenic compound according to claim 6 .
a thin film transistor array substrate having a pixel electrode and a common electrode;
a color filter array substrate facing the thin film transistor array substrate and including a color filter;
a liquid crystal layer interposed between the thin film transistor array substrate and the color filter array substrate; and
and a polarizing plate provided on at least one surface of the thin film transistor array substrate and the color filter array substrate,
The polarizing plate is a display device comprising the reactive mesogen compound according to claim 6 .

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