WO2015050346A1

WO2015050346A1 - Liquid crystal composition

Info

Publication number: WO2015050346A1
Application number: PCT/KR2014/009125
Authority: WO
Inventors: 유수영; 허두영; 김성진; 정철인; 이지연
Original assignee: 주식회사 엘지화학
Priority date: 2013-10-01
Filing date: 2014-09-29
Publication date: 2015-04-09

Abstract

The present application pertains to a liquid crystal composition, a liquid crystal film, and a display device. The present application can provide a liquid crystal composition which is capable of forming a liquid crystal layer that prevents the occurrence of a stain caused by a thickness difference or the like even in the case of forming the liquid crystal layer on a large area by means of coating, and which is also capable of being adequately soluble even in a solvent having low solubility, and forming the liquid crystal layer even on a base material layer exhibiting corrosivity to a raw material.

Description

Liquid crystal composition

The present application relates to a liquid crystal composition, a liquid crystal film and a display device.

Thinner, lighter, and larger manufacturing of liquid crystal displays (LCDs), plasma display panels (PDPs), or organic liquid crystal displays (OLEDs) is an ever-increasing need, and also to produce higher quality images. In order to improve screen uniformity, contrast ratio and viewing angle, researches are also being conducted.

An optical film including a brightness enhancing film, a retardation film, a viewing angle compensation film, and the like can be used for reducing the color change of a display device, securing a viewing angle, and improving brightness.

In such an optical film, the stretched film which extended | stretched the polymer film and provided optical anisotropy is known, and the system using the optical anisotropy of the liquid crystal film manufactured by hardening | curing a reactive liquid crystal compound is also known.

Patent document 1 has proposed the technique of using the said reactive liquid crystal compound.

The liquid crystal film is usually prepared by applying a coating solution in which RM (Reactive Mesogen) is dissolved in a solvent. However, solvents that exhibit proper solubility for the RM are extremely limited, which leads to manufacturing problems due to the inability to maintain liquid state for a suitable time during solvent drying after coating. In addition, stains may be generated due to thickness variation, and thus, a high solubility solvent must be used, thereby causing a problem of substrate erosion.

[Preceding technical literature]

[Patent Documents]

Patent Document 1: Republic of Korea Patent Publication No. 2013-0092816

The present application provides a liquid crystal composition, a liquid crystal film and a display device. The present application can provide a liquid crystal composition capable of exhibiting excellent solubility even in a variety of solvents, especially those known to exhibit low solubility in conventional RMs, and thus stains due to thickness batting even when produced by large area coatings. Preventing and preventing the problem of substrate erosion provides a good quality liquid crystal film.

It relates to a liquid crystal composition of the present application.

Exemplary liquid crystal compositions may include reactive liquid crystal compounds. In the present application, the term "reactive liquid crystal compound" may mean a compound including a moiety capable of exhibiting liquid crystal, for example, a skeleton of mesogen, and at least one reactive functional group, For example, it may mean a liquid crystal compound in a form including a backbone of the mesogen core and a spacer connecting a reactive functional group to the mesogen core.

In the present specification, the term "mesogen core" may mean a polymerizable mesogen or a liquid crystal compound which is a monomeric compound. In addition, the term "spacer" refers to a flexible organic group, and may mean a compound that connects the reactive functional group to the mesogenic core that can be polymerized. In addition, the term "reactive functional group" may mean a general term for a polymerizable group.

The liquid crystal composition may include a first reactive liquid crystal compound and a second reactive liquid crystal compound.

The first reactive liquid crystal compound and the second reactive liquid crystal compound may have a structure belonging to the following formula (1).

[Formula 1]

In Formula 1, M _C is a mesogen core, X is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O ( C = O) O-, L is an alkylene group, R is an alkenyl group, epoxy group, carboxyl group, cyano group, acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group, n is 2 or more.

Further, X in the first reactive liquid crystal compound and X in the second reactive liquid crystal compound are different from each other, or carbon number of the alkylene group of L in the first reactive liquid crystal compound and alkyl of L in the second reactive liquid crystal compound The carbon number of the len group is different from each other.

As the alkylene group in the present specification, unless otherwise specified, an alkylene group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms may be exemplified. The alkylene group may be linear, branched or cyclic. The alkylene group may be optionally substituted by one or more substituents.

In addition, as the alkenyl group in the present specification, unless otherwise specified, an alkenyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms may be exemplified. The alkenyl group may be linear, branched or cyclic. In addition, the alkenyl group may be optionally substituted by one or more substituents.

Substituents which may be substituted with any compound or substituent in the present specification include alkyl, alkoxy, alkenyl, epoxy, cyano, carboxyl, acryloyl, methacryloyl, acryloyloxy and methacrylo Iloxy group or aryl group may be exemplified, but is not limited thereto.

The skeleton of the mesogen core included in the first reactive liquid crystal compound and the second reactive liquid crystal compound may be the same. As used herein, the term "same skeleton of the mesogenic core" means that the rigid parts constituting the mesogenic core are the same, that is, for example, the same of the aromatic moiety and the linker connecting the aromatic moiety. Where the substituents are different in some of the residues it may be meant to include them.

The liquid crystal composition of the present application exhibits high solubility in various solvents including the first reactive liquid crystal compound and the second reactive liquid crystal compound while having the same skeleton of the mesogen core, thereby forming a liquid crystal layer by coating on a large area. In this case, it is possible to form a liquid crystal layer which does not generate stains due to the difference in thickness and the like, and can exhibit proper solubility even in a solvent having a low solubility, and can form a liquid crystal layer on a base layer exhibiting erosion to a solvent. have.

The mesogen core is connected by a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O (C = 0) O- Two or more or three or more benzene ring structures present. The mesogenic core is preferably at least 2 to at most 5, at least 2 to at most 4 or at least 2 to 3, connected by -C (= 0) O- or -O (C = 0)-. Up to benzene ring structures may be included.

Liquid crystal composition of the present application may be a number within the range of 2 to 10, 2 to 8, 2 to 6 or 2 to 5 in the formula (1).

In one example, the mesogen core may be represented by the following formula (2).

[Formula 2]

In formula (2), W is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O (C = 0) O-, R ₁ to R ₁₀ are each independently hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group or a substituent of Formula 3, wherein n substituents of R ₁ to R ₁₀ are each represented by X of Formula 1 and Form a radical to be connected, or m substituents of R ₁ to R ₁₀ form a radical connected to X of Formula 1, and p substituents form a radical connected to a substituent of Formula 3, provided that Where m and p are any numbers that satisfy m + p = n):

[Formula 3]

In Formula 3, B is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O (C = 0) O-, R ₁₁ to R ₁₅ each independently represent a hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a nitro group, wherein p substituents in R ₁₁ to R ₁₅ form a radical connected with X of Formula 1 .

As the halogen in the present specification, chlorine, bromine or iodine and the like can be exemplified.

As the alkyl group in the present specification, unless otherwise specified, a straight or branched chain alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms, or 3 to 20 carbon atoms, Cycloalkyl groups having 3 to 16 carbon atoms, 3 to 12 carbon atoms, 3 to 8 carbon atoms or 3 to 6 carbon atoms may be exemplified. The alkyl group may be optionally substituted by one or more substituents.

As the alkoxy group in the present specification, unless otherwise specified, an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms or 1 to 4 carbon atoms can be exemplified. The alkoxy group may be linear, branched or cyclic. In addition, the alkoxy group may be optionally substituted by one or more substituents.

In addition, in this specification, the code | symbol "

May mean that site is linked to a mother compound. For example, in the formula (2), the "

”May mean that B is directly connected to benzene of the formula (1).

As used herein, the term "single bond" may mean that no separate atom or atom group exists at the corresponding site. For example, in the above formulas (1) to (3), the term "single bond" means a case where no separate atom is present in a portion represented by A or B. For example, when W is a single bond in Formula 2, benzene on both sides of W may be directly connected to form a biphenyl structure.

The mesogen core included in the liquid crystal composition of the present application may be, for example, in the definition of Formula 2, for example, W may be -C (= 0) O- or -O (C = 0)-, R ₁ to R ₁₀ may each independently represent a hydrogen, a halogen, an alkyl group, a cyano group, or a substituent of Formula 3, wherein the positions of R ₃ and R ₈ in R ₁ to R ₁₀ may be linked to X or a substituent of Formula 3 It can be connected with.

In addition, in the definition of Chemical Formula 3, for example, B is preferably -C (= 0) O- or -O (C = 0)-, and R ₁₁ to R ₁₅ are each independently except n. It may be a hydrogen, a halogen, an alkyl group or a cyano group, and the position R ₁₄ of R ₁₁ to R ₁₅ may be a position to form a radical connected to X of the general formula (1).

In addition, in the definition of Chemical Formula 2 or 3, preferably m is a number in the range of 1 to 4, p may be 1 or 2.

In the liquid crystal composition of the present application, the blending ratio of the first and second reactive liquid crystal compounds may be selected in an appropriate range without particular limitation in consideration of the desired effect, for example, in comparison to 100 parts by weight of the first reactive liquid crystal compound. The second reactive liquid crystal compound may be included in the liquid crystal composition in a ratio of 1 part by weight to 1,000, 10 parts by weight to 500, 25 parts by weight to 250 parts by weight, or 50 parts by weight to 150 parts by weight. Unless otherwise specified in the present specification, the unit "parts by weight" may mean a ratio of weights between components.

The liquid crystal composition of the present application may include an additional reactive liquid crystal compound, for example, a third or fourth reactive liquid crystal compound, in addition to the first and second reactive liquid crystal compounds described above in consideration of the desired effect, and the additional reactive liquid crystal The compound may have the same skeleton of the aforementioned first and second reactive liquid crystal compounds and the mesogen core. The liquid crystal composition of the present application includes only two or more liquid crystal compounds having the same skeleton of the mesogenic core, and may exhibit appropriate solubility even in a solvent having low solubility as described below. A layer can be formed.

The liquid crystal composition of the present application may further include a polymerization initiator, and is not particularly limited, but the polymerization initiator may be, for example, a photopolymerization initiator.

The said photoinitiator can start superposition | polymerization of a reactive liquid crystal compound by irradiation of light, for example. In the present specification, the term "irradiation of light" refers to, for example, electromagnetic waves such as microwaves, infrared rays (IR), ultraviolet rays (UV), X-rays, and gamma rays, alpha-particle beams, and proton beams. It may mean irradiation of a particle beam such as a proton beam, a neutron beam, or an electron beam.

The kind of photoinitiator is not specifically limited, A suitable kind can be selected and used according to the objective. As a photoinitiator, benzyl (also called bibenzoyl), benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoyl benzoic acid, methyl benzoyl benzoate, 4-benzoyl-4'-methyldiphenyl sulfide, benzyl methyl Ketal, dimethylaminomethylbenzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, p-methylaminobenzoic acid isoamyl, 3-3'-dimethyl-4-methoxybenzophenone, methyllobenzoylfo Mate, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane -1-one, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenyl Propane-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-chlorothioxanthone, 2,4-diethylthioxanthone or 1-chloro 4-propoxythioxanthone and the like can be exemplified, and as necessary The photoinitiator may be used in combination with a suitable sensitizer.

The specific ratio of the photopolymerization initiator is not particularly limited, and an appropriate ratio may be selected according to the purpose. For example, the photopolymerization initiator may be included in a ratio of 1 part by weight to 10 parts by weight with respect to 100 parts by weight of the liquid crystal compound, but is not limited thereto. If the ratio of the photopolymerization initiator is too low, proper polymerization may not be induced. On the contrary, if the ratio of the photopolymerization initiator is too high, physical properties may deteriorate due to the remaining initiator after formation of the liquid crystal layer, and an appropriate ratio may be selected in consideration of this.

The liquid crystal composition may further comprise a surfactant. As the surfactant, for example, a fluorocarbon-based or silicone-based surfactant may be exemplified. Fluorocarbon-based surfactants can be exemplified by Fluorad FC4430, Fluorad FC4432, Fluorad FC4434, or Zonyl, Dupont, USA, and the like. Chemie BYK and the like can be exemplified, but is not limited thereto.

The ratio of the surfactant is not particularly limited, and may be included, for example, about 0.05 to 5 parts by weight based on 100 parts by weight of the horizontally oriented liquid crystal compound. If the ratio of the surfactant is too low, the surface state of the liquid crystal layer may be poor, and if it is too high, staining due to the surfactant may occur, an appropriate ratio may be selected in consideration of this.

The liquid crystal composition of the present application may further include a solvent.

The solvent is not particularly limited, but may be, for example, a solvent having a solubility at room temperature of 10 or less with respect to the reactive liquid crystal compound of Formula 4 below.

[Formula 4]

As used herein, the term "solubility" may mean a gram number (g) of the solute as a conventionally used meaning, for example, the maximum amount of solute that can be dissolved in 100 g of a solvent at a constant temperature. g / (solvent) 100 g "or the said unit may be abbreviate | omitted and shown in this specification abbreviate | omitted. In addition, in the present specification, the solute may mean the liquid crystal compound described above. In addition, the term "room temperature" in the present specification is a natural temperature without heating or cooling, for example, may mean a temperature of about 10 ℃ to about 30 ℃, about 15 ℃ to about 30 ℃ or about 25 ℃. have.

The lower the solubility of the solvent, the lower limit is not particularly limited in the present application because it is possible to select a variety of solvents, for example, the solubility of the solvent is 9, 8, 7, 6 for the reactive liquid crystal compound of Formula 4 at room temperature Or five. In addition, the solubility of the solvent may vary depending on the type of specific solvent, for example, may be 10 or less, 15 or less or 20 or less with respect to the reactive liquid crystal compound of Formula 4 at room temperature.

The liquid crystal composition of the present application can exhibit appropriate solubility even in a solvent having a low solubility, and can form a liquid crystal layer on a base layer exhibiting erosion to a solvent.

Specific examples of the solvent include ketone solvents such as methyl ethyl ketone or methyl isobutyl ketone; Ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol methyl ether, propylene glycol dimethyl ether or propylene glycol diethyl ether; Halogenated solvents such as chloroform, methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane or 1,1,2-trichloroethene; Aromatic hydrocarbon solvents such as hexane, heptane, octane, cyclohexane, benzene, toluene or xylene; Alcohol solvents such as methanol, ethanol, isopropanol, propanol, butanol or t-butanol; Acetate solvents such as propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, 3-methoxybutyl acetate, ethylene glycol acetate, ethyl cellosolve acetate, methyl cellosolve acetate, and butyl acetate; Or it can mix and use 1 or more types from the group which consists of cellosolves, such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve. The solvent is preferably included in the form of a mixed solvent, and the mixing ratio between the solvents included in the mixed solvent is not particularly limited, but an appropriate ratio in consideration of the desired effect, for example, physical properties such as coating properties It can be mixed with.

In addition to the above, the liquid crystal composition may further include a known additive, for example, a stabilizer or a nonpolymerizable non-liquid crystal compound, if necessary.

The present application also relates to a liquid crystal film.

An exemplary liquid crystal film may include a liquid crystal layer formed by the liquid crystal composition.

1 exemplarily shows a liquid crystal film of the present application. As shown in FIG. 1, the liquid crystal film includes, for example, a base layer 20; The alignment layer 30 present on the substrate layer 20 and the liquid crystal layer 40 present on the alignment layer 30 may be included.

As a base material layer contained in the said liquid crystal film, For example, As a plastic base material layer, Cellulose base layers, such as TAC (triacetyl cellulose) or DAC (diacetyl cellulose); Cyclo olefin polymer (COP) substrate layers such as norbornene derivatives; An acrylic base layer such as poly (methyl methacrylate), a polycarbonate base layer, a polyolefin base layer such as polyethylene (PE) or polypropylene (PP), a polyvinyl alcohol (PVA) base layer; Polyether sulfone (PES) base layer; polyetheretherketon (PEEK) base layer; polyetherimide (PEI) base layer; polyethylene naphthalate (PEN, polyethylenenaphthatlate) base layer; polyethylene terephtalate A polyester base layer such as), a polyimide (PI) base layer, a polysulfone (PSF, polysulfone) base layer, or a fluoropolymer base layer such as an amorphous fluorine resin, etc. may be exemplified. As a base material layer of a film, a polycarbonate base material layer can be used.

In the liquid crystal film, an alignment film existing between the base layer and the liquid crystal layer may be a known alignment film, for example, an optical alignment film, without being limited in kind, and may be formed by other known methods such as rubbing polymerization.

The liquid crystal layer which may be formed on the alignment layer in the liquid crystal film may be prepared by, for example, coating, aligning and curing the liquid crystal composition described above or a coating solution prepared using the same on the alignment layer.

The liquid crystal layer can be formed by, for example, applying the liquid crystal composition onto the alignment film, and aligning and polymerizing the liquid crystal compound. The liquid crystal composition can be prepared, for example, by dissolving the polymerizable liquid crystal compound in an appropriate solvent. Specifically, a liquid crystal composition can be manufactured by dissolving a polymeric liquid crystal compound and a photoinitiator in a solvent.

In addition to the above components, a chiral agent, a surfactant, a polymerizable monomer, a polymer, and the like may be further added to the liquid crystal composition in a range that does not prevent the alignment of the liquid crystal molecules.

In the preparation of the liquid crystal composition, for example, halogenated hydrocarbons such as chloroform, tetrachloroethane, trichloroethylene, tetrachloroethylene and chlorobenzene; Aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, cymene, methoxy benzene and 1,2-dimethoxybenzene; Ketones such as acetone, methyl ethyl ketone, cyclohexanone or cyclopentanone; Alcohols such as isopropyl alcohol or n-butanol; Solvents such as cellosolves such as methyl cellosolve, ethyl cellosolve or butyl cellosolve can be used.

After apply | coating the liquid crystal composition containing a polymeric liquid crystal compound on an oriented film, and drying, it can orientate and polymerize. Drying may be carried out for at least 1 minute at a temperature of about 25 ℃ to 120 ℃. The drying temperature is a factor that can affect the alignment of the liquid crystal, induces proper alignment of the liquid crystal molecules in the above range, and can prevent staining and the like.

Following the drying process, the coating layer is irradiated with light, for example ultraviolet rays, to polymerize the liquid crystal compound. Such polymerization can be done in the presence of a photoinitiator that absorbs wavelengths in the ultraviolet region. In addition, the crosslinking reaction in the above-described alignment film may also be induced by the light irradiation.

Ultraviolet irradiation can be carried out in the atmosphere or under a nitrogen atmosphere in which oxygen is blocked to increase the reaction efficiency. The ultraviolet irradiator may be generally performed using a medium or high pressure mercury ultraviolet lamp or a metal halide lamp with an intensity of 80 w / cm or more. If necessary, a cold mirror or other cooling device may be provided between the base layer and the ultraviolet lamp so that the surface temperature of the liquid crystal layer at the time of ultraviolet irradiation becomes a temperature range having a liquid crystal state.

The liquid crystal film may be used, for example, as a retardation film or a viewing angle compensation film for a display device, a protective film of a polarizer, or the like.

In addition, the manufacturing method of the required liquid crystal film other than the above-mentioned content can employ | adopt a well-known system, and is not specifically limited.

The present application also relates to a display device such as a liquid crystal display device or the like. An exemplary liquid crystal display device may include the liquid crystal film.

The liquid crystal film may be useful, for example, as an optical compensation substrate layer for a liquid crystal display device, and thus the liquid crystal film may be included in the device as an optical compensation substrate layer. The film may be, for example, a phase difference film such as a super twist nematic (STN) LCD, a thin film transistor-twisted nematic (TFT-TN) LCD, a vertical alignment (VA) LCD, or an in-plane switching (IPS) LCD. ; λ / 2 waveplate; λ / 4 waveplate; Reverse wavelength dispersion film; Optical compensation films; Color filters; Laminated film with a polarizing plate or a polarizer; It can be used as a polarizing plate compensation film or the like.

An exemplary liquid crystal display device including the liquid crystal film will be described below.

That is, the liquid crystal display device includes a liquid crystal panel and first and second polarizing plates disposed on both surfaces of the liquid crystal panel, respectively, and the liquid crystal film is between the liquid crystal panel and the first polarizing plate and / or the liquid crystal. The panel may be disposed between the panel and the second polarizing plate.

In the above, the first and / or second polarizing plate may include a protective film on one or both surfaces. As the protective film, a TAC film, a polynorbornene film made of a ring opening metathesis polymerization (ROMP), a ring opening metathesis polymerization followed by hydrogenation (HROMP) polymer prepared by hydrogenating a cycloolefin polymer (COPP) which is ring-opened polymerized again, It may be a polyester film or a polynorbornene-based film prepared by addition polymerization, and the like, but a film made of a transparent polymer material may be used as a protective film, but is not limited thereto.

The liquid crystal composition according to the present application can form a liquid crystal layer which does not generate stains due to thickness differences even when a liquid crystal layer is formed by coating on a large area, and can exhibit proper solubility even in a solvent having low solubility. As such, a liquid crystal composition capable of forming a liquid crystal layer on a base material layer exhibiting erosion to a solvent may be provided.

FIG. 1: is a figure which shows typically the structure of the liquid crystal film which concerns on one example of this application.

Hereinafter, the present application will be described in more detail with reference to examples according to the present application and comparative examples not according to the present application, but the scope of the present application is not limited to the examples given below.

The physical properties in the following Examples and Comparative Examples were evaluated in the following manner.

1. 용해도 측정1. Solubility measurement

The liquid crystal compositions prepared in Examples and Comparative Examples were frozen for 24 hours at a temperature of −8 ° C. and then visually observed whether the injected liquid crystal compositions were precipitated and evaluated according to the following evaluation criteria.

○: No precipitation of the liquid crystal composition was observed.

(Triangle | delta): Only part of precipitation of a liquid crystal composition is observed.

X: Precipitation of a liquid crystal composition is observed remarkably.

2. 휘점의 개수 측정2. Measure the number of bright spots

In order to measure the number of bright spots for the liquid crystal films prepared in Examples 1, 4, Comparative Example 1 and Comparative Example 5, the liquid crystal film is positioned between the two polarizing plates having the absorption axis of the polarizing plate at an angle of 90 degrees on the backlight. After the optical axis of the liquid crystal film was matched with the absorption axis of one of the two polarizing plates, the number of brightly bright spots (bright spots) was measured based on 1 m ² .

3. 위상차 얼룩 정도3. Phase difference staining degree

In order to measure the degree of retardation unevenness with respect to the liquid crystal films produced in Examples 1, 4, Comparative Example 1 and Comparative Example 5, the liquid crystal film between the two polarizing plates in which the absorption axis of the polarizing plate is angled 90 degrees on the backlight. And position the optical axis of the liquid crystal film at an angle of 45 degrees with the two polarizing plate absorption axes. In this case, the light transmittance of the backlight is changed according to the phase difference of the liquid crystal film, and accordingly, the difference according to the phase difference of the liquid crystal film is represented as a difference (phase difference spot) of transmitted light. When the thickness was 2 μm, the degree of retardation unevenness appearing in each liquid crystal film was visually observed and evaluated according to the following evaluation criteria.

(Circle): The smudge which appeared on the liquid crystal film is hardly observed.

X: The stain | stain which appeared on the liquid crystal film is visually observed remarkably.

실시예 1Example 1

액정 조성물의 제조Preparation of Liquid Crystal Composition

2-methyl-1,4-phenylene bis (4-(((4- (acryloyloxy) butoxy) carbonyl) oxy) benzoate) which is a liquid crystal compound of the formula (A) 4-phenylene bis (4-(((4- (acryloyloxy) butoxy) carbonyl) oxy) benzoate, LC242, BASF Co., Ltd.) and 2-methyl-1,4-phenylene bis which is a liquid crystal compound of formula (B) (4- (3- (acryloyloxy) propoxy) benzoate) (2-methyl-1,4-phenylene bis (4- (3- (acryloyloxy) propoxy) benzoate, RM 257, MERCK company (product)) ) Were each combined in a weight ratio of 1: 1, and then the mixture was added to a solvent (A) in which cyclohexane, propylene glycol methyl ether acetate, and 2-butoxyethanol were mixed at a weight ratio of 4: 2: 4. It was added so as to have a concentration of 25% by weight, and 2 parts by weight of Irgacure 907 (manufactured by BASF Corporation) as an initiator was added to 100 parts by weight of solids to prepare a liquid crystal composition (A1) in the form of a solution.

[Formula A]

[Formula B]

액정 필름의 제조Production of liquid crystal film

After the alignment film was formed on one surface of the TAC base layer in a known manner, the liquid crystal composition was coated to have a thickness of about 1 μm after drying, and then heated in an oven at 60 ° C. for 2 minutes to remove the solvent inside the coating film. Subsequently, the dried coating film was irradiated with ultraviolet rays (light source: 300mJ / cm ² high pressure mercury lamp) and cured to prepare a liquid crystal film.

실시예 2Example 2

In Example 1, a solvent (B) obtained by mixing methyl ethyl ketone, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 instead of the solvent (A) was added at a concentration of 25% by weight. Except that, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Example 1.

실시예 3Example 3

Except that in Example 1, instead of the solvent (A), a solvent (C) mixed with toluene, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 was added so as to have a concentration of 25% by weight. Then, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Example 1.

실시예 4.Example 4.

2-Methyl-1,4-phenylene bis (4- (3- (acryloyloxy) butoxy) which is a liquid crystal compound of Formula A, a liquid crystal compound of Formula B, and a liquid crystal compound of Formula C Example 1 and 2, except that benzoate) (2-methyl-1,4-phenylene bis (4- (3- (acryloyloxy) butoxy) benzoate, TRM24) was combined at a weight ratio of 1: 1: 1, respectively. In the same manner, a liquid crystal composition and a liquid crystal film were prepared.

[Formula C]

실시예 5Example 5

In Example 4, a solvent (B) obtained by mixing methyl ethyl ketone, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 instead of the solvent (A) was added at a concentration of 25% by weight. Except that, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Example 4.

실시예 6Example 6

Except that in Example 4, instead of the solvent (A), toluene, propylene glycol methyl ether acetate and 2-butoxyethanol were mixed in a weight ratio of 4: 2: 4 so that the solvent (C) was added at a concentration of 25% by weight. Then, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Example 4.

실시예 7Example 7

Except that in Example 4, instead of the solvent (A), the solvent (D) mixed with propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 6: 4 was added so as to have a concentration of 25% by weight, A liquid crystal composition and a liquid crystal film were prepared in the same manner as in 4.

비교예 1Comparative Example 1

2-Methyl-1,4-phenylene bis (4-(((4- (acryloyloxy) butoxy) carbonyl) oxy) benzoate) which is a liquid crystal compound of the formula (A) as a liquid crystal compound (2-methyl- Liquid crystal composition in the same manner as in Example 1, except that only 100% of 1,4-phenylene bis (4-(((4- (acryloyloxy) butoxy) carbonyl) oxy) benzoate, LC242, manufactured by BASF Corporation) was used. And a liquid crystal film.

비교예 2Comparative Example 2

In Comparative Example 1, a solvent (B) obtained by mixing methyl ethyl ketone, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 instead of the solvent (A) was added to a concentration of 25% by weight. Except that, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Comparative Example 1.

비교예 3Comparative Example 3

Except that in Comparative Example 1 a solvent (C) mixed with toluene, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 instead of the solvent (A) to a concentration of 25% by weight Then, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Comparative Example 1.

비교예 4Comparative Example 4

Comparative Example 1, except that the solvent (D) in which propylene glycol methyl ether acetate and 2-butoxyethanol were mixed at a weight ratio of 6: 4 instead of the solvent (A) was added so as to have a concentration of 25% by weight. In the same manner as in 1, a liquid crystal composition and a liquid crystal film were prepared.

비교예 5Comparative Example 5

As a liquid crystal compound, 2-methyl-1,4-phenylene bis (4-(((4- (acryloyloxy) butoxy) carbonyl) oxy) benzoate) which is a liquid crystal compound represented by the above formula (A) (2-methyl -1,4-phenylene bis (4-(((4- (acryloyloxy) butoxy) carbonyl) oxy) benzoate, LC242, manufactured by BASF Corporation) and 2-methyl-1,4- which are liquid crystal compounds of the formula (B) Phenylene bis (4- (3- (acryloyloxy) propoxy) benzoate) (2-methyl-1,4-phenylene bis (4- (3- (acryloyloxy) propoxy) benzoate, RM 257, MERCK company (C) and 4-cyanophenyl 4- (4- (acryloyloxy) butoxy) benzoate, which is a liquid crystal compound represented by the following formula (D), RM23 ) And a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Example 1.

[Formula D]

비교예 6Comparative Example 6

In Comparative Example 5, a solvent (B) obtained by mixing methyl ethyl ketone, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 instead of the solvent (A) was added so as to have a concentration of 25% by weight. Except that, a liquid crystal composition and a liquid crystal film were prepared in the same manner as in Comparative Example 5.

비교예 7Comparative Example 7

Except that in Comparative Example 5, instead of the solvent (A), a solvent (C) obtained by mixing toluene, propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 4: 2: 4 was added so as to have a concentration of 25% by weight. And the liquid crystal composition and the liquid crystal film were produced in the same manner as the comparative example 5.

비교예 8Comparative Example 8

Comparative Example 5, except that the solvent (D) mixed with propylene glycol methyl ether acetate and 2-butoxyethanol in a weight ratio of 6: 4 instead of the solvent (A) was added to a concentration of 25% by weight, Comparative Example A liquid crystal composition and a liquid crystal film were produced in the same manner as in 5.

Physical properties and evaluation results measured for each of the Examples and Comparative Examples are as shown in Tables 1 and 2 below.

Table 1

division

Example

Comparative example

One

2

3

4

5

6

7

One

2

3

4

5

6

7

8

Solubility

○

△

○

×

TABLE 2

division	Example		Comparative example
division	One	4	One	5
Bright point (unit)	0.5	0.3	2	4
Phase difference	○	○	×	×

As confirmed from Tables 1 and 2 above, the liquid crystal composition according to the present application may exhibit appropriate solubility even in a solvent having low solubility, and may not only form a liquid crystal layer on a base layer exhibiting erosion to a solvent. In the case where the liquid crystal layer is formed by coating on a large area, it was confirmed that a liquid crystal layer can be formed in which unevenness due to a thickness difference does not occur.

[Description of the code]

20: base material layer

30: alignment film

40: liquid crystal layer

Claims

A first reactive liquid crystal compound and a second reactive liquid crystal compound represented by Formula 1, respectively, wherein the skeleton of the mesogen core (Mc) of the first and second reactive liquid crystal compounds is the same, and the first and second A liquid crystal composition which does not contain a reactive liquid crystal compound having a different skeleton of a mesogen core from a reactive liquid crystal compound:

[Formula 1]

In Formula 1, M C is a mesogen core, X is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O ( C = O) O-, L is an alkylene group, R is an alkenyl group, epoxy group, carboxyl group, cyano group, acryloyl group, methacryloyl group, acryloyloxy group or methacryloyloxy group, n is 2 or more, wherein X in the first reactive liquid crystal compound and X in the second reactive liquid crystal compound are different from each other, or carbon number of the alkylene group of L in the first reactive liquid crystal compound and L in the second reactive liquid crystal compound Carbon number of the alkylene group of is mutually different.
The method of claim 1 wherein the mesogen core is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O (C = 0). Liquid crystal composition comprising two or more benzene ring structure connected by O-.
3. The liquid crystal composition of claim 2, wherein the mesogen core comprises at least three benzene ring structures.
The liquid crystal composition of claim 1, wherein the mesogen core is represented by the following Chemical Formula 2:

[Formula 2]

In formula (2), W is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O (C = 0) O-, R 1 to R 10 are each independently hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group or a substituent of Formula 3, wherein n substituents of R 1 to R 10 are each represented by X of Formula 1 and Form a radical to be connected, or m substituents of R 1 to R 10 form a radical connected to X of Formula 1, and p substituents form a radical connected to a substituent of Formula 3, provided that Where m and p are any numbers that satisfy m + p = n):

[Formula 3]

In Formula 3, B is a single bond, -O-, -C (= 0)-, -C (= 0) O-, -O (C = 0)-or -O (C = 0) O-, R 11 to R 15 each independently represent a hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a nitro group, wherein p substituents in R 11 to R 15 form a radical connected with X of Formula 1 .
The liquid crystal composition of claim 1, wherein n is a number in the range of 2 to 5.
The liquid crystal composition of claim 4, wherein in the definition of Chemical Formula 2, m is a number in the range of 1 to 4, and p is 1 or 2. 6.
The liquid crystal composition of claim 1, wherein the liquid crystal composition comprises the second reactive liquid crystal compound at 1 part by weight to 1,000 parts by weight based on 100 parts by weight of the first reactive liquid crystal compound.
The liquid crystal composition according to claim 1, further comprising a polymerization initiator.
The liquid crystal composition of claim 1, further comprising a solvent having a solubility of 10 or less in a room temperature of a reactive liquid crystal compound of Formula 4 below:

[Formula 4]
A liquid crystal film comprising a liquid crystal layer formed from the liquid crystal composition of claim 1.
The liquid crystal film according to claim 10, further comprising a base layer, wherein a liquid crystal layer is formed on one surface of the base layer.
The method of claim 11, wherein the substrate layer is a cellulose substrate; Cyclic olefin polymer substrates; Acrylic substrates; Polycarbonate substrates; Polyolefin substrates; Polyvinyl alcohol base; Polyether sulfone substrates; Polyether ether ketone substrates; Polyetherimide substrates; Polyethylene naphthalate substrates; Polyester substrates; Polyimide substrates; The liquid crystal film which is a liquid crystal film which is a polysulfone base material or a fluoropolymer base material.
The liquid crystal film according to claim 11, further comprising an alignment film existing between the base layer and the liquid crystal layer.
A display device comprising the liquid crystal film of claim 12.