KR20130134067A - Rod-like liquid crystal compound and preparation method thereof - Google Patents

Abstract

The present invention relates to a rod-shaped liquid crystal compound and a preparation method thereof and, more specifically, to a liquid crystal compound and a preparation method thereof, wherein the compound has nematic properties capable of optical arrangement by providing carbazole or a fluorene rod-shaped structure. The liquid crystal compound according to the present invention can easily fix the liquid crystal compound by immediately performing photopolymerization after optically arranging the liquid crystal compound since a photopolymerization group is included in a terminal. Moreover, the liquid crystal compound of the present invention allows the manufacture of optical compensatory films, FPR, and the like and allows minute optical compensation.

Description

Rod-shaped liquid crystal compound and its manufacturing method {ROD-LIKE LIQUID CRYSTAL COMPOUND AND PREPARATION METHOD THEREOF}

The present invention relates to a rod-like liquid crystal compound and a method for manufacturing the same, and more particularly, to a liquid crystal compound having nematic properties capable of optical arrangement by having a carbazole or fluorene rod-like structure in the molecular structure of the compound and its It relates to a manufacturing method.

In recent years, display devices have been rapidly developed, and among them, liquid crystal displays (LCDs) are representative of current display devices.

The liquid crystal display (LCD) includes a liquid crystal cell and a polarizer, and expresses pixels using a principle of selectively passing light by polarization according to the arrangement of liquid crystal polymers in the liquid crystal cell positioned between the polarizers. do.

The liquid crystal cell includes a rod-shaped liquid crystal compound and an electrode layer disposed on a pair of substrates, and the liquid crystal cell largely includes twisted nematic (TN), in-plane switching (IPS), super twisted nematic (STN), and VA ( vertically aligned mode). However, when the display device is composed of only the liquid crystal cell and the polarizer, when the screen is viewed from a different viewing angle away from the vertical rather than the front of the screen, brightness or contrast may be remarkably lowered or light leakage may occur. (M. Schadt, К. Schmitt, V. Kozenkov, and G. Chigrinov., Jpn. J. App. Phys. 31, 2155, 1992); Marusii T., Reznikov Yu., Molecular Materials, 3 , 161, 1993).

Accordingly, liquid crystal displays generally include optical compensation films in addition to liquid crystal cells and polarizing elements (M. Oh-e and K. Kond, Appl. Phys. Lett., 67, p. 3895, 1995; SG Kim, SM Kim, YS Kim, HK Lee, SH Lee, G.-D. Lee, J.-J.Lyu, and KH Kim, Appl. Phys. Lett., 90, p.261910, 2007).

That is, an optical compensation film such as a retardation film or a viewing angle compensation film is attached to a polarizing element, or the retardation film or a viewing angle compensation film is attached to a display panel separately. The optical compensation film is essentially used in the liquid crystal display because it compensates the refraction due to the anisotropy of the liquid crystal cell, and prevents the image displayed on the display from being colored and enlarges the viewing angle.

Optical compensating film for use in the above-mentioned applications is divided into a large stretched, stretched film to give an optical anisotropy by stretching the polymer film, and a liquid crystal film made by applying a polymerizable liquid crystal compound on a plastic film substrate, dried and irradiated with ultraviolet rays to cure There is this. Both the stretched film and the liquid crystal film have optical anisotropy, and in particular, the liquid crystal film may have various types of optical properties that are difficult to realize in the stretched film.

In order to meet the high expectations for liquid crystal displays, optical compensation of superior liquid crystal cells is required, and optical compensation films are required for this purpose. However, it is difficult to meet these expectations for stretched films that have been given optical anisotropy by stretching. .

Accordingly, the present inventors have made an effort to produce an optical compensation film capable of more excellent optical compensation, and as a result, have prepared a liquid crystal compound having excellent optical compensation properties which can be usefully used in manufacturing the optical compensation film and completed the present invention.

After all, the main object of the present invention is to provide a liquid crystal compound and a method for manufacturing the optical compensation film that can be more precise and excellent optical compensation than conventional stretch birefringent polymer film.

In addition, another object of the present invention to provide an optical compensation film using the liquid crystal compound.

In addition, another object of the present invention to provide a FPR (Film patterned retarder) display device using the optical compensation film.

In order to achieve the above object, the present invention includes a portion of the naphthalene-carbazole or naphthalene-fluorene rod form showing the nematic properties, it is possible to compensate for a wide viewing angle and improvement of optical properties, and also easy to form a film To provide a compound.

In the present invention, the liquid crystal compound is characterized in that the photopolymerization group is introduced at the terminal, so that the aligned liquid crystal compound can be easily fixed by photopolymerization after the alignment of the liquid crystal compound.

Specifically, the present invention provides a liquid crystal compound represented by Chemical Formula 1 or Chemical Formula 2 having a terminal group having naphthalene-carbazole or naphthalene-fluorene as a main chain in a rod-shaped portion showing nematic properties and simultaneously capable of photopolymerization.

[Formula 1]

(2)

In the present invention, R ₁ and R ₄ of the formula are hydrogen atoms, alkyl group having 1 to 25 carbon atoms; An alkoxy group having 1 to 25 carbon atoms; A hydrogen atom, phenyl substituted with an alkyl group having 1 to 25 carbon atoms or substituted with an alkoxy group having 1 to 25 carbon atoms; A hydrogen atom, a pyrrole substituted with an alkyl group having 1 to 25 carbon atoms or substituted with an alkoxy group having 1 to 25 carbon atoms; An arylene group in which a hydrogen atom, an alkyl group having 1 to 25 carbon atoms is substituted, or an alkoxy group having 1 to 25 carbon atoms is substituted; An aryl group substituted with a hydrogen atom and an alkoxy group having 1 to 25 carbon atoms substituted with an alkyl group having 1 to 25 carbon atoms; It is preferably selected from the group consisting of aryl groups having 10 to 25 carbon atoms having a fused aromatic ring compound, R ₂ and R ₃ is a hydrogen atom; An alkyl group having 1 to 15 carbon atoms; A hydrogen atom, phenyl substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, or a pyrrole substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, an arylene group substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, or an aryl group substituted with an alkyl group having 1 to 15 carbon atoms; It is preferably selected from the group consisting of aryl groups having 1 to 15 carbon atoms having a fused aromatic ring compound.

More preferably, R ₂ and R ₃ of the above formula are represented by the following formula (3).

(3)

However, n is an integer of 1 to 15, R ₅ is selected from methyl acrylate or methyl methacrylate.

The rod-type liquid crystal compound has various orientations such as planar, homeotropic, tilted, spread, and cholesteric, and thus the optical properties resulting from it are diverse and unique. . Therefore, various alignment characteristics of the liquid crystal can be applied as it is, and various applications are possible.

Since the liquid crystal compound according to the present invention has the advantages of the rod-type liquid crystal compound and at the same time includes a photopolymerizer at the end thereof, the optically aligned liquid crystal compound is easily fixed by performing photopolymerization immediately after the optical alignment. This makes it easy to manufacture optical compensation films and the like.

According to an embodiment of the present invention, the liquid crystal compound is represented by Planner Fluorene Naphthalene 4 (P-FN4) of Formula 4 or Planner Carbazole Naphthalene 6 (P-CNP6) of Formula 5.

[Chemical Formula 4]

[Chemical Formula 5]

In addition, the liquid crystal compound of the present invention may be prepared according to the procedure of Schemes 1 to 5.

However, the method for producing the liquid crystal compound of the present invention does not need to be particularly limited, and any method for preparing a compound satisfying the above formula (1) or (2) may be used.

[Reaction Scheme 1]

[Reaction Scheme 2]

Scheme 3

[Reaction Scheme 4]

[Reaction Scheme 5]

In the present invention, the liquid crystal compound prepared as described above exhibited high thermal stability at 5 wt% loss of about 377 ° C. and 400 ° C., and showed high transmittance of 98% or more.

The present invention also provides an optical compensation film comprising a compound represented by the formula (1) or (2).

The optical compensation film may be prepared by a known method commonly used in the art, preferably, preparing a film to be used as a substrate; Applying a liquid crystal compound of the present invention to one surface of the substrate; And polymerizing the compound applied to the substrate. In addition, in the above, the liquid crystal compound may be prepared by further comprising the step of light irradiation to have anisotropy.

In addition, the optical compensation film exhibits optical characteristics, and the kind thereof is not limited. Examples of the optical compensation film according to the present invention include a retardation film, a viewing angle compensation film, a protective film and the like.

The present invention also provides a display device including the optical film.

The type of the display device is not particularly limited, but may be preferably applied to a FPR (Film patterned retarder) display device.

The present invention as described above has an effect of providing a liquid crystal chemical having a terminal group capable of photopolymerization, including naphthalene-carbazole or naphthalene-fluorene in a rod-shaped portion showing nematic properties.

Since the liquid crystal compound according to the present invention has a rod-type liquid crystal compound and has a photopolymerization group at the end thereof, the liquid crystal compound can be easily fixed by performing photopolymerization immediately after the optical alignment of the liquid crystal compound. have.

In addition, the liquid crystal compound of the present invention is easy to manufacture the optical compensation film and FPR, and precise optical compensation is possible.

1 is a ¹ H-NMR spectrum of the compound represented by Formula 4 according to an embodiment of the present invention.
2 is a ¹ H-NMR spectrum of the compound represented by Formula 5 according to an embodiment of the present invention.
3 is a thermogravimetric analysis (TGA) graph of the compound represented by Formula 4 and Formula 5 according to an embodiment of the present invention.
4 is a UV absorption spectrum of the compound represented by Formula 4 and Formula 5 according to an embodiment of the present invention.
5 is a differential scanning calorimetry (DSC) graph of the compound represented by Chemical Formula 4 according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples.

It is to be understood by those skilled in the art that these examples are for illustrative purposes only and that the scope of the present invention is not construed as being limited by these examples.

Example 1 Preparation of Compound (B) (Scheme 1)

30 g of sodium hydroxide (NaOH, Three Angels) was dissolved in 30 ml of water to remove gas, followed by nitrogen replacement, followed by 2,7-dibromo-9 hydrogen-fluorene (2,7-dibromo-9H-fluorene). , 5.0 g of Aldrich, 0.50 g of tetrabutylammonium bromide were added thereto, and 11.6 mL of 1-bromobutane was added dropwise and stirred at 70 ° C. for 11 hours.

After completion of the reaction, the organics were extracted and ethanol (Ethanol, Samcheonsa) recrystallized to obtain 6.3 g of Compound A (2,7-dibromo-9,9-dibutyl-9H-fluorene).

6 g of Compound A was dissolved in 30 ml of dried THF, and the temperature was lowered to -78 ° C. Then, 21 equivalents of 2.2 equivalents of normal butyllithium (n-BuLi, Aldrich) were slowly added.

The reaction mixture was stirred at -78 ° C for 2 hours, so that 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2-Isopropoxy-4,4,5 , 5-tetramethyl-1,3,2-dioxaborolane, Aldrich, Inc.) was added thereto, and the mixture was stirred at -78 ° C for 2 hours, and then stirred for 24 hours while gradually raising the temperature to room temperature. At the end of the reaction, the organics were extracted with chloroform, washed with water and recrystallized with hexane to give Compound B 2,2 '-(9,9-dibutyl-9H-fluorene-2,7-diyl) bis (4,4,5, 6.32 g of 5-tetramethyl-1,3,2-dioxaborolane) were obtained.

Example 2. Preparation of Compound (E) (Scheme 2)

16.78 g of potassium hydroxide (KOH, Aldrich) and 5 g of carbazole (Aldrich) were added and vacuum-substituted under nitrogen. Then, 142 ml of dimethylformamide (DMF) was added, followed by 2-bromopropane (2). -bromopropane) was added slowly and stirred at 90 ° C for 24 hours.

After removing under reduced pressure, the organics were extracted with chloroform and washed, and then water was removed and recrystallized to obtain 4.94 g of Compound C (9-isopropyl-9H-carbazole).

4 g of the compound C was dissolved in 120 mL of THF, and 7.14 g of n-bromosuccinimide (NBS, Aldrich) was added little by little, followed by stirring at 65 ° C. for 24 hours. When the reaction was terminated, the organics were extracted and washed with chloroform (Chloroform, Samcheonsa), water was removed and purified by column to obtain 4.71 g of Compound D (3,6-dibromo-9-isopropyl-9H-carbazole).

1 g of the compound D was dissolved in 23 ml of dried THF, and the temperature was lowered to −78 ° C., followed by slowly adding 2.2 equivalents of normal butyllithium (n-BuLi, Aldrich). The reaction mixture was stirred at -78 ° C for 2 hours, so that 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2-Isopropoxy-4,4,5 , 5-tetramethyl-1,3,2-dioxaborolane, Aldrich Co., Ltd.) was added, and the mixture was stirred at −78 ° C. for 2 hours, and then stirred for 24 hours while gradually raising the temperature to room temperature.

After the reaction was completed, the organics were extracted with chloroform, washed with water and purified by column to obtain Compound E (9-isopropyl-3,6-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- 0.36 g of yl) -9H-carbazole) was obtained.

Example 3. Preparation of Compound (G) (Scheme 3)

15.48 g of potassium carbonate (K ₂ CO _3, Aldrich), 5 g of 6-bromonaphthalenol (6-bromonaphthalen-ol), and 4.47 mL of 4-chlorobutanol (4-chlorobutan-1-ol) were added thereto, followed by vacuum. Nitrogen substitution was carried out, and dimethyl formamide (DMF, Samcheonsa) was added thereto, and the mixture was stirred at 90 ° C. for 48 hours.

After removing under reduced pressure, the organic material was extracted and washed with chloroform (Chloroform, Samcheonsa), and then water was removed and purified by column to obtain 2.57 g of compound F (6- (6-bromonaphthalen-2-yloxy) hexan-1-ol). .

5 g of the compound F was dissolved in 50 ml of methylene chloride (three thousand yarn), triethylamine (triethylamine, Aldrich) was added thereto, and the mixture was stirred at 0 ° C. for 1 hour.

Dissolve acryloyl chloride (acryloyl chloride, Aldrich) in 20 ml of methylene chloride (three thousand) and dropwise at 0 ° C. and stir at 0 ° C. for 1 hour. After the completion of the reaction, the mixture was extracted with chloroform (chloroform, Samcheonsa) and purified by column to obtain 3.00 g of compound G (6- (6-bromonaphthalen-2-yloxy) hexyl acrylate).

Example 4 Preparation of P-NF4 (Scheme 4)

1 g of the compound B prepared in Examples 1 and 3 and 1.56 g of the compound G were dissolved in 20 ml of dried THF, and 0.30 g of tetrakisritriphenylphosphinepalladium (0, Aldrich) was added thereto. After stirring for 10 minutes, 10 ml of aqueous 2 mol potassium carbonate (K ₂ CO ₃ , Aldrich) was added thereto, and the mixture was stirred at 80 ° C. for 48 hours.

After completion of the reaction was purified to obtain 1.1g of the reactive liquid crystal (Reactive Mesogen, RM) compound P-FN4 (Planner Fluorene Naphthalene 4) of the formula (4).

Example 5. Preparation of P-CNP6 (Scheme 5) (Scheme 5)

1 g of Compound E prepared in Examples 2 and 3 and 1.29 g of Compound G were dissolved in 20 ml of dry THF, and 0.29 g of tetrakis (triphenylphosphine) palladium (tetrakistriphenylphosphinepalladium (0), Aldrich) was added thereto. After stirring for 10 minutes, 10 ml of a 2 mol potassium carbonate (K ₂ CO ₃ , Aldrich) aqueous solution was added thereto, and the mixture was stirred at 80 ° C. for 48 hours.

After completion of the reaction was purified to obtain 0.9g of the reactive liquid crystal (RM) compound P-CNP6 (Planner Carbazole Naphthalene 6) of the formula (5).

Experimental Example 1

Thermogravimetric analysis (TGA) and UV measurements were performed using the compounds of Examples 4 and 5.

As a result of TGA measurement, P-FN4 and P-CNP6 have thermal stability of 5% at 401 ℃ and 377 ℃, respectively, and UV stability is 99% at 400 ~ 900nm for both materials. It confirmed that it had the above transmittance | permeability.

5 is a diagram illustrating differential scanning calorimetry (DSC) of liquid crystal molecules represented by Chemical Formula 4 prepared in Example 4. FIG.

Having described specific portions of the present invention in detail, those skilled in the art will appreciate that these specific descriptions are only for the preferred embodiment and that the scope of the present invention is not limited thereby. It will be obvious. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

Rod-shaped liquid crystal compound represented by the formula (1).
[Chemical Formula 1]

Provided that R ₁ is a hydrogen atom or an alkyl group having 1 to 25 carbon atoms; An alkoxy group having 1 to 25 carbon atoms; A hydrogen atom, phenyl substituted with an alkyl group having 1 to 25 carbon atoms or substituted with an alkoxy group having 1 to 25 carbon atoms; A hydrogen atom, a pyrrole substituted with an alkyl group having 1 to 25 carbon atoms or substituted with an alkoxy group having 1 to 25 carbon atoms; An arylene group in which a hydrogen atom, an alkyl group having 1 to 25 carbon atoms is substituted, or an alkoxy group having 1 to 25 carbon atoms is substituted; An aryl group substituted with a hydrogen atom and an alkoxy group having 1 to 25 carbon atoms substituted with an alkyl group having 1 to 25 carbon atoms; It is preferably selected from the group consisting of aryl groups having 10 to 25 carbon atoms having a fused aromatic ring compound, R ₂ and R ₃ is a hydrogen atom; An alkyl group having 1 to 15 carbon atoms; A hydrogen atom, phenyl substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, or a pyrrole substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, an arylene group substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, or an aryl group substituted with an alkyl group having 1 to 15 carbon atoms; And an aryl group having 1 to 15 carbon atoms having a fused aromatic ring compound.
The method of claim 1,
Wherein R ₂ is a bar-shaped liquid crystal compound, characterized in that represented by the formula (3).
(3)

However, n is an integer of 1 to 15, R ₅ is selected from methyl acrylate or methyl methacrylate.
A rod-shaped liquid crystal compound represented by the following formula (2).
(2)

Provided that R ₄ represents a hydrogen atom and an alkyl group having 1 to 25 carbon atoms; An alkoxy group having 1 to 25 carbon atoms; A hydrogen atom, phenyl substituted with an alkyl group having 1 to 25 carbon atoms or substituted with an alkoxy group having 1 to 25 carbon atoms; A hydrogen atom, a pyrrole substituted with an alkyl group having 1 to 25 carbon atoms or substituted with an alkoxy group having 1 to 25 carbon atoms; An arylene group in which a hydrogen atom, an alkyl group having 1 to 25 carbon atoms is substituted, or an alkoxy group having 1 to 25 carbon atoms is substituted; An aryl group substituted with a hydrogen atom and an alkoxy group having 1 to 25 carbon atoms substituted with an alkyl group having 1 to 25 carbon atoms; It is preferably selected from the group consisting of aryl groups having 10 to 25 carbon atoms having a fused aromatic ring compound, R ₂ and R ₃ is a hydrogen atom; An alkyl group having 1 to 15 carbon atoms; A hydrogen atom, phenyl substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, or a pyrrole substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, an arylene group substituted with an alkyl group having 1 to 15 carbon atoms; A hydrogen atom, or an aryl group substituted with an alkyl group having 1 to 15 carbon atoms; And an aryl group having 1 to 15 carbon atoms having a fused aromatic ring compound.
The method of claim 3,
R ₃ is a rod-shaped liquid crystal compound, characterized in that represented by the formula of the following formula (3).
(3)

However, n is an integer of 1 to 15, R ₅ is selected from methyl acrylate or methyl methacrylate.
Rod-shaped liquid crystal compound represented by the formula (4).
[Chemical Formula 4]

The rod-shaped liquid crystal compound represented by the formula (5).
[Chemical Formula 5]

An optical compensation film comprising the liquid crystal compound of any one of claims 1 to 6.
Display device comprising the optical compensation film of claim 7.

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