KR100988412B1 - Lyotropic Chromonic Liquid Crystal Composition - Google Patents

Abstract

The present invention relates to a mammary chromonic liquid crystal composition, wherein the mammary chromonic liquid crystal composition according to the present invention comprises a basic chromonic liquid crystal compound and an acidic monomer.

According to the present invention, by using the liquid crystal composition comprising the basic chromonic liquid crystal compound and the acidic monomer, it is possible to improve the electrical and optical properties such as mechanical strength, insulating properties and refractive index of the optical film formed therefrom.

Mastogenic, chromonic, monomeric, acidic, basic, composition

Description

Lyotropic Chromonic Liquid Crystal Composition

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mammary chromic liquid crystal composition, and more particularly, to polarizing plates, color filters, and retardation films applied to image display devices such as liquid crystal displays (LCDs) and organic electroluminescent devices (OLEDs). In manufacturing a film applied to an optical film or other microelectronics, optical, communication, computer technology, biosensor, etc., using a chromonic liquid crystal composition, the mammary chromonic liquid crystal with high hardness and improved cohesive stability between liquid crystals It relates to a composition.

For example, in a liquid crystal display device, a polarizing film and a retardation film are used in combination with an optical film to induce various polarization characteristics.

Among these, the thing which extended | stretched using the polyvinyl alcohol (PVA) which used iodine as a dye as a polarizer is used normally. The optical activity in these films is determined by the dichroism of the raw material consisting of the PVA-dye used. However, iodine has a problem of insufficient durability such as heat resistance or light resistance because of its high sublimability.

In order to solve this problem, an azo dye (for example, direct blue or direct red) is applied as a dichroic dye instead of iodine. However, such azo dye can secure durability, but is substantially inferior to the iodine dye. By showing dichroism, there exists a limit in expressing favorable optical characteristics.

Similarly, in optical compensation films such as retardation films, Japanese Patent No. 3174367 and the like combine a lambda / 4 phase difference film and a lambda / 2 phase difference film formed by stretching a modified cellulose film, a modified polycarbonate film, etc. An example of laminating an optical compensation film or a retardation film on a polarizing plate has been proposed, but the optical axis of the retardation film made of the stretched film as described above is changed according to the stretching direction.

That is, each film should be cut out and laminated in accordance with the direction of each optical axis, and the films should be laminated so that the absorption axis and the retardation axis are at preferred angles. More specifically, the absorption axis of the polarizing plate is generally parallel to the stretching direction thereof, and the retardation axis of the retardation film is also parallel to the stretching direction thereof. Therefore, in order to laminate the polarizing plate and the retardation film at, for example, an angle of 45 ° between the absorption axis and the slow axis, one of the films must be cut out in the direction of 45 ° with respect to the stretching direction of the film. When the film is cut and glued in this way, for example, the angle between the optical axes is changed for all the cut films, and the quality of all the products is changed, resulting in a costly and time-consuming process of manufacturing the product. do.

Therefore, in recent years, an optical film in which a liquid crystal compound as a water-soluble organic dye is coated as an optical film material having a planar molecular structure has been proposed.

Typically, US Pat. Nos. 2,400,877 and US 2,544,659 apply a solution of a dichroic material to a base film and evaporate the solvent from the applied surface to transform the dichroic material into a nematic phase, while at the same time a molecule of the material. A method of solidifying by orienting in a direction is shown. The dichroic nematic material is a water or alcohol soluble organic dye, which is converted into a nematic phase on the surface of the base film.

Liquid crystal means that molecules have an orientative order in the long-range, while positional order is reduced (one-dimensional position on the static) Refer to a state of matter that exhibits absent (nematic phase) characteristics.

Due to this intermediate order of liquid crystal, liquid crystal is defined as a material positioned between a crystalline solid having an even positional and directional order and an isotropic fluid having no order. Solid crystals or isotropic fluids can be transformed into the liquid crystal phase by changing the temperature or by changing the concentration by adding a suitable solvent. Commonly, a liquid crystal formed by temperature change, such as the former, is called a thermotropic liquid crystal, and a liquid crystal formed by concentration, such as the latter, is called a lyotropic liquid crystal.

The orientation method of a thermotropic liquid crystal is based on the fixation of a liquid crystal compound by the process to the specific direction of a base film. This treatment is disclosed in US Pat. No. 5,596,434. According to the said patent, after a base film is apply | coated with a polymer layer, such as a polyimide, a base film is processed by the method of mechanically rubbing. The rubbing direction determines the alignment direction of the thermotropic liquid crystal. The alignment phenomenon between the anisotropic base film and the liquid crystal array is referred to as "anchoring", and the alignment method by surface anchoring is commonly used in display devices using thermotropic liquid crystals. The surface is treated with a polymer or surfactant to obtain the desired orientation properties.

The alignment of the breast liquid crystal has a side that is more difficult than the alignment of the thermotropic liquid crystal. This is because most breast-like liquid crystals are made of amphiphilic materials having both hydrophilicity and hydrophobicity. Amphoteric molecules have a polar (hydrophilic) head and a nonpolar (hydrophobic) aliphatic chain tail. When these amphoteric molecules are in contact with the base film, they are generally arranged in a direction perpendicular to the plane of the base film due to the amphoteric properties of the liquid crystal. This orthogonal orientation means that the optical axis is orthogonal to the base film. Here, the concentration and structure of a specific molecule have a great influence in determining the arrangement order of liquid crystals. Typical mammary liquid crystals have a long column shape mainly made of rod-shaped or stacking of discotic or flank-shaped molecules. Have

Among the types of mammary liquid crystals, a lot of attention is received as a useful substance, lyotropic chromonic liquid crystal (hereinafter referred to as "LCLC"). LCLC is flexible and hydrophilic around hard, plank-shaped aromatic molecules, unlike ordinary breast-like liquid crystals of amphoteric substances, with ionic functional groups at one end of a rod-like aliphatic chain molecule. Or a structure having an ionic functional group.

The LCLC is widely used in dyes, pharmaceuticals, nucleic acids, antibiotics, anticancer agents and the like. The molecular structure and macrostructure of the LCLC are as shown in FIGS. 1A and 1B. That is, as shown in Figure 1a, in the aqueous solution, the head portion of the hydrophilic group (1) is directed to the outside, the tail portion of the hydrophobic group (2) is aggregated (aggregated), have a micellar structure (micellar), or As shown in FIG. 1B, molecules having the hydrophilic group 3 attached to the planar aromatic hydrophobic core 4 are laminated. This is called self-assembly, and this self-assembly has a stable orientation characteristic, attracting attention as a material used in various optical elements.

Here, the stacked structure between the molecules is formed by the π-π interaction between the aromatic cores 4. J. Lydon, Chromonics: Handbook of Liquid Crystals (Wiley-VCH, Weinheim, 1998) v. 2B, p. 981 and Current Opin. Col. Inter. Sci. 3, 458 (1998)] is also water soluble due to hydrophilic ionic functionality around the molecule.

These LCLC materials have recently been the subject of intensive research by proving that they can be used as internal polarizers of liquid crystal displays. T. Sergan et al .: Liquid Crystals v. 5, pp. 567-572 (2000)]

For example, US Pat. No. 5,948,487 or International Patent PCT / US2000 / 031181 discloses structures oriented using nematic chromic liquid crystal materials containing one or more triazine groups, and US Pat. No. 6,570,632 A method is disclosed in which a chromonic material comprising chromoline (C ₂₃ H ₁₄ O ₁₁ Na ₂ ) is applied onto a glass substrate, rubbed and oriented, and dried to remove the solvent to obtain an optical film.

However, even by the above methods, in the case of an optical film formed by applying an LCLC composition formed in an aqueous solution or a solution phase containing an organic solvent and then drying it, in the self-assembly process of liquid crystal molecules, Segregation phenomenon occurs and cracks are likely to occur in the remaining liquid crystal compositions due to the volume reduction caused by the removal of a large amount of solvent during drying, and the hardness and the substrate of the film itself. Since the bonding strength with the film is weak, there is a problem that it is easy to peel off, and also the cohesion between the molecular aggregates of the liquid crystal dye is weakly formed, the stability of the thin film is low, and the difficulty of overcoming the difficult process conditions due to the humidity of the aqueous solution environment. This happens. It is also possible for the optical film produced to lose its oriented state upon contact with water and return to the optical isotropic state.

Therefore, in view of the low bond strength between the molecular aggregate of the liquid crystal dye and the low bond strength between the aggregate and the base film, a means for increasing the strength of the interaction between the base film and the liquid crystal dye is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to use a monomer instead of an aqueous solution used in a chromic liquid crystal composition, orient it, and then cure it, thereby curing between the molecular aggregates of the liquid crystal dye and the aggregates. The present invention provides a breast chromic liquid crystal composition capable of increasing the bond strength between the base film and the base film to obtain an optical film having high surface hardness and no cracking even after drying.

The breast chromic liquid crystal composition according to the present invention comprises a basic chromic liquid crystal compound and an acidic monomer.

That is, the cation of the basic functional group surrounding the aromatic hydrophobic core of the chromonic liquid crystal compound and the anion of the acidic monomer as a counter-ion interact with each other to produce a mammary chromic liquid crystal having a new functional group, In the case of curing the composition, by the polymerization reaction by the new functional group, the bond between the respective molecular aggregates forming a laminated structure in the liquid crystal dye and the bond between the molecular aggregates and the base film are strengthened, and thus Excellent mechanical, optical and electrical properties can be attained.

Hereinafter, a look at the technical configuration of the present invention.

(1) basic chromonic liquid crystal compound

As described above, the chromonic liquid crystal compound has a form in which a hydrophilic functional group is surrounded around a rigid, plank-shaped aromatic molecule (hydrophobic core).

Here, as the "basic chromic liquid crystal compound" used in the present invention, a hydrophilic functional group having a basic bound to a hydrophobic core is used, and the basic hydrophilic functional group (hereinafter referred to as a "basic functional group") When the mixture is reacted with an acidic monomer to be described later, a cation is formed to ionic bond with an anion of the acidic monomer, and the bonded monomer polymerizes with an additional monomer present in the composition to form a molecule stacked as a breast liquid crystal. A tight bond between the aggregates is achieved.

Such chromonic liquid crystal compounds are described in J. Lydon, Chromonics: Handbook of Liquid Crystals (Wiley-VCH, Weinheim, 1998) v. 2B, p. 981 and Current Opin. Col. Inter. Sci. 3, 458 (1998)], T. Sergan et al .: Liquid Crystals v. 5, pp. 567-572 (2000), wherein the basic functional group has a form surrounding an aromatic ring (hydrophobic core).

Here, the term "basic functional group" refers to a functional group directly contacting an aromatic ring, and is not particularly limited as long as it is a basic functional group. And a functional group in which nitrogen ions (N ⁺ ) are expressed upon reaction with an acidic monomer.

The basic functional group is generally present in the form of an amine group, an imine group, or the like as described above, or the nitrogen ions (N ⁺ ) and other anions are bonded to exist in the form of salts, which are described later. When reacted with, the nitrogen ions (N ⁺ ) are exposed to bond with the anions of the acidic functional groups of the acidic monomers.

Specific examples of the basic chromonic liquid crystal compound are as shown in the following formulas (I-1) to (I-11). However, the basic chromonic liquid crystal compound is not limited to the following chemical formula.

Formula I-1

(Formula I-2)

Formula I-3

Formula I-4

Formula I-5

Formula I-6

(Formula Ⅰ-7)

(Formula Ⅰ-8)

Formula I-9

(Formula Ⅰ-10)

Formula I-11

(Me는 메틸기를 포함한 알킬기) 또는 HCOO 중 어느 하나이며, X는 수소 또는 할로겐 원자(Cl, Br 등)이다.In Formulas I-1 to I-11, R is an alkyl group or a hydrogen atom, A is Cl,

(Me is either an alkyl group including a methyl group) or HCOO, and X is hydrogen or a halogen atom (Cl, Br, etc.).

The basic chromonic liquid crystal compound is preferably contained in 5 to 40% by weight, preferably 10 to 30% by weight based on the total composition. The content range of the basic chromonic liquid crystal compound is a preferred range for the liquid crystal composition to exist with the properties of the liquid crystal between the solid crystal and the isotropic fluid.

(2) acidic monomers

As described above, in the case of a conventional optical film obtained by mixing a chromonic liquid crystal compound and an aqueous solution, orienting the mixed solution, and drying the same, cracks are liable to occur during the drying of the aqueous solution, and cohesion between liquid crystal molecules is increased. There was a problem of weakening.

Thus, in the present invention, by using an acidic monomer instead of an aqueous solution to generate a strong ionic bond with the basic functional group of the chromic liquid crystal compound, and the polymerization by performing the polymerization in the state that the bonded liquid crystal molecules are laminated orientation, By inducing strong bonds between them, strong cohesion and high surface hardness between liquid crystal molecules were obtained.

The "acidic monomer" used in the present invention is not particularly limited as long as the monomer has an acidic functional group corresponding to the basic functional group of the basic chromonic liquid crystal compound, and the carboxylate when reacted with the basic chromonic liquid crystal compound ( ^{COO-acrylate-based} monomer include salts, ester group, a carboxyl group, such as ^-) ions are expressed COO; Monomers including a phosphate, phosphine group, phosphate group, phosphonic acid group, etc. in which phosphate ions (PO ₃ ⁻ ) are expressed during the reaction; Monomers including sulfonic acid salts, sulfonic acid groups, etc., in which sulfonic acid ions (SO ₃ ⁻ ) are expressed during the reaction, and typically, metal salts of (meth) acrylic acid, crotonic acid, maleic acid or itaconic acid, 2-acrylamic acid Fig. 2-methyl propane sulfonate, sulfo propyl acrylate or methacrylate or other water soluble forms or other polymerizable carboxylic or sulfonic acids, sulfomethylated acrylamide, aryl sulfonate, sodium vinyl sulfonate, and the like. It may be included alone or in combination of one or more selected from them. In addition, the acidic monomers used in the present invention are as shown in the following formula (II-1) to (II-19).

Formula II-1

Formula II-2

Formula II-3

Formula II-4

In the above formula, n = 0 to 3.

(Formula II-5)

In the above formula, A is hydrogen, an alkali metal cation or primary to quaternary ammonium cation, n = 0 to 3.

Formula II-6

Formula II-7

Formula II-8

Formula II-9

(Formula II-10)

Formula II-11

In the above formula, A is hydrogen, an alkali metal cation or primary to quaternary ammonium cation, n = 0 to 3.

Formula II-12

Formula II-13

In the above formula, A is hydrogen, an alkali metal cation or primary to quaternary ammonium cation.

Formula II-140

In the above formula, A is hydrogen, an alkali metal cation or primary to quaternary ammonium cation.

Formula II-15

(Formula II-16)

(Formula II-17)

(Formula II-18)

In the above formula, A is hydrogen, an alkali metal cation or primary to quaternary ammonium cation.

Formula II-19

(3) polymerization initiator

The breast chromic liquid crystal composition according to the present invention may further include a polymerization initiator such as a photoinitiator and a thermal initiator for facilitating polymerization after the alignment, together with the basic chromonic liquid crystal compound and the acidic monomer.

The photoinitiator used in the present invention is used in the case of photopolymerizing the composition by ultraviolet light, specifically, diethoxyacetphenone, 2-hydroxy-2-methyl-1-phenyl propane-1-one, benzyldimethyl ketal, 1 Acetphenones, such as -hydroxycyclohexyl phenyl ketone and 2-methyl-2-morphine (4-thiomethylphenyl) propane-1-one, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzo Benzoin ethers such as phosphorus isobutyl ether, benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfonic acid, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzophenones such as benzenemethananium bromide and (4-benzoylbenzyl) trimethylammonium chloride, 2,4-diethylthioxanthone, 1- Thioxanthones such as chloro-4-dichlorothioxanthone, 2, 4, 6-trimethylbenzoyldiphenylbenzoyl oxide and the like alone It can be used in combination. Moreover, as an accelerator (sensitizer), amine compounds, such as N, N- dimethyl paratoluidin, and 4, 4'- diethylamino benzophenone, can also be used individually or in mixture.

In addition, in the case of thermally polymerizing the mammary chromonic liquid crystal composition according to the present invention, a thermal initiator is used. As the thermal initiator, organic peroxide free radical initiators such as diacyl peroxides, peroxy ketals, ketone peroxides, hydroperoxides, dialkyl peroxides, peroxy esters and peroxydicarbonates can be used. Can be. Specifically, lauroyl peroxide, benzoyl peroxide, cyclohexanone peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, t-butylhydroperoxide and the like May be mentioned. Alternatively, a combination of persulfate / bisulfite can be used.

The content of the polymerization initiator is preferably in the range of 0.01 wt% to 10 wt%, more preferably 0.5 wt% to 5 wt%, in 100 wt% of the composition. If the content of the polymerization initiator is less than 0.1% by weight, it is difficult to obtain a polymerization effect. If the content of the polymerization initiator is more than 10% by weight, too much polymerization initiator is added as compared to the polymerization initiation effect, resulting in low economic efficiency.

(4) additives and solvents

In addition, the mammary chromic liquid crystal composition used in the present invention may further include an additive in some cases, and may be added a solvent such as an organic solvent and water to facilitate viscosity control. Examples of the additives include a nonionic vinyl monomer added to enable copolymerization with the acidic monomer to control the physical properties of the prepared thin film, a leveling agent for increasing the smoothness of the composition, and reducing the surface tension of the composition. Wetting agent (wetting agent), ultraviolet stabilizer, heat stabilizer, conductive surfactant, crosslinking monomer, anti-aging agent, denaturing agent or other material to improve the wettability to the base film. As the conductive surfactant, quaternary ammonium is preferable.

The nonionic vinyl monomer is a copolymerizable nonionic ethylenically unsaturated monomer well known in the art. Preferred nonionic vinyl monomers are compounds represented by the following general formula (III) or (IV).

Formula III

CH ₂ = C (X) Z

(IV)

CH ₂ = CH-OC (O) R

In formulas (III) and (IV), X is H or methyl; Z is -C (O) OR ¹ , -C (O) NH ₂ , -C (O) NHR ¹ , -C (O) N (R ¹ ) ₂ , -C ₆ H ₄ R ¹ , -C ₆ H ₄ OR ¹ , -C ₆ H ₄ Cl, -CN, -NHC (O) CH ₃ , -NHC (O) H, N- (2-pyrrolidonyl), N-caprolactamyl, -C (O ) NHC (CH ₃ ) ₃ , -C (O) NHCH ₂ CH ₂ , -N-ethyleneurea, -SiR ₃ , -C (O) O (CH ₂ ) xSiR ₃ , -C (O) NH (CH ₂ ) xSiR ₃ or-(CH ₂ ) xSiR ₃ ; x is an integer from 1 to about 6; Each R is independently C ₁ -C ₁₈ alkyl; Each R ¹ is independently C ₁ -C ₃₀ alkyl, hydroxy substituted C ₂ -C ₃₀ alkyl or halogen substituted C ₁ C ₃₀ alkyl.

Suitable water insoluble nonionic vinyl monomers include C ₁ -C ₃₀ alkyl (meth) acrylates; C ₁ -C ₃₀ alkyl (meth) acrylamide; Styrene; Substituted styrenes such as vinyl toluene (ie 2-methylstyrene), butyl styrene, isopropyl styrene, p-chlorostyrene and the like; Vinyl esters such as vinyl acetate, vinyl butyrate, vinyl caprolate, vinyl pivalate, vinyl neodecanoate, and the like; Unsaturated nitriles such as methacrylonitrile, acrylonitrile and the like; And unsaturated silanes such as trimethylvinylsilane, dimethylethylvinylsilane, allyldimethylphenylsilane, allyltrimethylsilane, 3-acrylamidopropyltrimethylsilane, 3-trimethylsilylpropyl methacrylate, and the like, but are not limited thereto. It is not.

Examples of suitable water soluble nonionic vinyl monomers include C ₂ -C ₆ hydroxyalkyl (meth) acrylates; Glycerol mono (meth) acrylate; Tris (hydroxymethyl) ethane mono (meth) acrylate; Pentaerythritol mono (meth) acrylate; N-hydroxymethyl (meth) acrylamide; 2-hydroxyethyl (meth) acrylamide; 3-hydroxypropyl (meth) acrylamide; (Meth) acrylamide; N-vinyl caprolactam; N-vinyl pyrrolidone; Methacrylamidoethyl-N-ethyleneurea (ie, CH 2 = C (CH 3) C (O) NHCH 2 CH 2 -N-ethyleneurea), C 1 -C 4 alkoxy substituted (meth) acrylates and (Meth) acrylamides such as methoxyethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, and the like; And combinations thereof, but is not limited thereto.

Particularly preferred nonionic vinyl monomers include C ₁ -C ₁₈ alkyl esters of acrylic acid and methacrylic acid, methacrylic amidoethyl-N-ethylene urea and combinations thereof.

Specific examples of the crosslinking monomer include an acrylic polyfunctional monomer, an epoxy crosslinking agent, a metal chelate crosslinking agent, a silane crosslinking agent, an aldehyde, a N-methylol compound, a dioxane derivative, a compound acting by activating a carboxyl group, an active vinyl compound, and an activity. Halogen compounds, isoxazoles, and dialdehyde starches; These can be used individually or in combination of 2 or more types.

Preferably, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, phenoxyethyldi (meth) acrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, neopentyl glycol tri (Meth) acrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, bisphenol A diethoxy diacrylate, hexanediol diacrylate, Two or more such as tripropylene glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, diethylene glycol diacrylate, divinylbenzene, diallyl ether, di (meth) acrylamide Nonionic vinyl monomers or anionic vinyl monomers having vinyl functional groups can be used alone or in combination.

As said anti-aging agent, a phenol type compound, an amine compound, an organic sulfur type compound, a phosphine type compound is mentioned, for example. As said modifier, glycols, silicones, and alcohols are mentioned, for example. The said surfactant is used in order to smooth the surface of an optical film, for example, Surfactant, such as silicone type, acryl type, and fluorine type, is mentioned as a specific example.

In addition, dispersants, terminators, curing agents, ozonation agents, antioxidants, plasticizers, viscosity modifiers such as thickeners and fillers, flocculants that function to improve the intimacy of interparticle contact after being deposited on a substrate, and ultraviolet, infrared Or specific compounds that function as dyes and pigments that absorb visible light. For example, dimethylaminopyridine (DMAP) is mentioned as an additive which improves optical transparency.

As the solvent, water may be used. Organic solvents such as alcohols, acetates, ethers, glycols, ketones, and carbonates, dimethyl formaldehyde (DMF), dimethyl sulfoxide (DMSO), Any one of aprotic polar organic solvents such as N-methylpyrrolidone (NMP) and N, N-dimethylacetamide (DMAc) may be used alone or in combination of two or more thereof, preferably dimethyl formaldehyde. (DMF) or methanol is used alone or in combination.

As for the addition amount of such an additive and a solvent, 0.01-40 weight% is added with respect to 100 weight% of compositions, More preferably, 0.1-35 weight% is added. By adding an additive and a solvent in the above range, the most desirable properties can be expressed through a combination with the chromonic compound and the monomer.

Next, a method of manufacturing an optical film or the like using the mammary chromonic liquid crystal composition according to the present invention will be described.

The manufacture of a thin liquid crystal film having anisotropic properties is an important field to be treated as an important application area of chromic liquid crystals. The composition used in the present invention is applied to the base film, and then cured to form a solid film, thereby having properties useful as a polarizing plate, an optical compensation film, a retarder, an alignment film, a color filter, and the like.

In general, the mammary chromic liquid crystal composition is coated on a base film, oriented in a predetermined direction, and then curing the composition by a photopolymerization or a thermal polymerization method, wherein the orientation method is a strong magnetic field. It is possible to use a variety of known methods, such as using, using an alignment film, or using a shear (shear).

Coating method is spin coating, dip coating, flow coating, spray coating, roll coating, gravure coating, micro gravure coating -Gravure Coating) can be used.

As the most basic orientation method, a method of rubbing the surface of the base film or photoaligning a polymer having a photoactive group such as azobenzene may be used to prepare an alignment film.

In addition, a liquid crystal cell using a chromonic liquid crystal on a plate N phase or twisted chiral nematic (N *) may be utilized as a phase difference film having negative birefringence. [M.Lavrentovich, T. Sergan and J. Kelly , Liq. Cryst., 2003, 30, 851] This is according to the method of providing a flat phase N-phase liquid crystal cell using two glass substrates coated with the rubbed polyimide as an alignment film, and filling the composition.

After treating the nonionic polymer coating layer having an azobenzene functional group by linearly polarized light to form an alignment layer, it may be followed by a method of coating the chromonic liquid crystal composition thereon.

The shear force alignment method is performed by applying a shear force on the composition coating layer after coating the composition on a substrate film in the form of a mammary liquid crystal phase, so that the axis of the chromonic liquid crystal molecules is oriented perpendicular to the direction in which the shear force is applied. do.

After the alignment of the liquid crystal molecules is carried out, it is cured by photopolymerization or thermal polymerization. FIG. 2A is an acryl group represented by Formula V-2 (hereinafter referred to as “20”) as an acidic monomer and a chromic liquid crystal compound represented by Formula V-1 having basicity (perylenedicarboxyimide, hereinafter referred to as “10”) and an acidic monomer. Arbitrary acrylic acid with "" is mixed and reacted to show the structure of the unit molecular aggregate formed after the polymerization is carried out using a composition comprising molecules bound in the form of Formula V-3.

(Formula Ⅴ-1)

(Formula Ⅴ-20

(Formula Ⅴ-3)

When the basic chromic liquid crystal compound 10 and the acidic acrylic acid 20 are mixed and reacted, the chromic liquid crystal molecules 10 and the acrylic acid in the form of a disc are formed by an acid-base reaction, as shown in Formula V-3. (20) is dissolved in an excess of acrylic acid (20) in the form of a salt (salt) in the form of a mammary liquid crystal phase, while being laminated by self-organization of chromic liquid crystal molecules When thermal polymerization or photopolymerization is performed, acrylic acid 20 bonded to the hydrophobic core 10 and the external acrylic acid 20 not bonded to the hydrophobic core 10 are polymerized together in the form shown in FIG. 2A. Strong bonding structures 20 'are formed between the molecular aggregate layers.

Figure 2b is a view showing a polarizing film formed by the composition. That is, the chromic liquid crystal molecules 10 and the polymerized acrylic acid bonding structure 20 'are self-assembled and aligned on the base film 100.

The liquid crystal film thus prepared may be used as an optical film and the like, and a brief description will be made of a method of manufacturing a micro patterned polarizer, which has recently been studied.

Micropatterns of anisotropic aromatics have been studied using the self-assembly of chromic liquid crystals, and micropattern polarizers manufactured therefrom are used in holographic films and microelectronic fields using optical materials whose image changes depending on the viewing angle. , And stereoscopic imaging.

3 is a view sequentially showing an embodiment of a method of manufacturing the micro pattern polarizer. As shown in FIG. 3, in the method of manufacturing a micro patterned polarizer, the composition 200 including the photocuring initiator according to the present invention on the base film 100 is oriented in a predetermined direction by the aforementioned shear force alignment method. Coating (a), placing the patterned photomask 300 on the liquid crystal composition 200, selectively curing the liquid crystal composition 200 by irradiating ultraviolet rays (c), and then removing the photomask 300 Is performed by removal (d).

When the selective curing process is finished, an additional process of selectively converting the non-exposed portions other than the exposed and cured portions into an isotropic state may be used to produce a micro pattern polarizer. That is, the selective isotropic state switching of the non-exposed part can be achieved by the following method. Since the non-exposed part is not cured, it is selectively removed by using a solubility-developing solution, or converted to an isotropic state again by changing the concentration due to evaporation of heat or acidic monomers, and then irradiating the entire remaining film with ultraviolet light, the exposed part is oriented. The non-exposed part is in an isotropic state in the obtained liquid crystal phase.

In addition, the liquid crystal composition 200 may include various additives used in manufacturing a conventional photoresist, a monomer for crosslinking, and the like.

According to the present invention, by using the liquid crystal composition comprising the basic chromonic liquid crystal compound and the acidic monomer, it is possible to improve the electrical and optical properties such as mechanical strength, insulating properties and refractive index of the optical film formed therefrom.

Hereinafter, the present invention will be described from an experimental point of view through an experimental example of the mammary chromic liquid crystal composition according to the present invention.

Experimental Example

0.05 g of Red 2304 (manufactured by Optiva) represented by Chemical Formula I-10 as a basic chromonic liquid crystal compound on a glass substrate, 0.01 ml of 2-carboxy ethyl acrylate of Chemical Formula II-3, and a photoinitiator as an acidic monomer ( Irgacure 907, manufactured by Ciba) 0.0025 g of the coating was mixed by spin coating, and then the coating layer was rubbed in the longitudinal direction using a rubber plate, and applied by irradiating with light of 20 mJ / cm ² using a metal halogen lamp. The liquid crystal layer was cured to obtain a liquid crystal layer having a thickness of 2 μm.

4 is an optical microscope showing whether the liquid crystal coating layer formed according to the experimental example is rotated at 0 °, 45 °, and 90 ° with respect to orthogonal polarization, respectively, and transmits orthogonal polarization to the liquid crystal coating layer to show polarization characteristics. It is the photograph observed by. The surface of the liquid crystal coating layer which rotated the polarization axis to 0 degrees, 45 degrees, and 90 degrees respectively from the left photograph was shown. As shown in FIG. 4, the liquid crystal coating layer formed by the mammary chromic liquid crystal composition according to the present invention has the largest transmittance when rotated at 45 ° and hardly transmits light at 0 ° and 90 °. have.

This is because the liquid crystal molecules are anisotropic by the shear force coating, and thus the darkest state occurs when the orthogonal polarization coincides with the direction of the polarizer, and the brightest state when the liquid crystal molecules form a 45 ° angle with the polarizer. That is, it can be confirmed from this experiment that the coating layer of the liquid crystal composition according to the present invention exhibits excellent polarization characteristics, and the liquid crystal coating layer formed by the above experimental example exhibits circular polarization film characteristics with an optical axis of 0 °.

Comparative example

A liquid crystal coating layer was formed in the same manner as in Experimental Example except that water was mixed instead of an acidic monomer to form a composition in an aqueous solution.

Evaluation experiment for the liquid crystal coating layer formed by the above experimental example and the comparative example was performed as follows.

(1) coating film appearance

The liquid crystal coating layer formed by the experimental example and the comparative example was photographed with a polarizing microscope.

5a and 5b are photographs taken of the surface of the liquid crystal coating layer formed by the experimental and comparative examples, respectively.

As shown in FIGS. 5A and 5B, almost no surface cracks are found in the liquid crystal coating layer formed by the Experimental Example, but the liquid crystal coating layer formed by the Comparative Example has surface cracks (black cracked portions) in part. You can see that.

(2) pencil hardness

The surface of the liquid crystal coating layer according to the experimental and comparative examples, respectively, by evaluating the hardness of the liquid crystal coating layer formed by the experimental and comparative examples with pencils having different hardnesses by the test method of ASTM D3502, respectively, and rotating the polarization axis by 45 °. Was observed with a polarizing microscope. The results are shown in Table 1 below.

                  Surface observation result with increasing hardness of pencil Experimental Example
Surface photo

Hardness of pencil HB F H 2H 3H Comparative example
Surface photo

Hardness of pencil 6B 5B 4B 3B 2B

In the surface photograph of Table 1, the black marks on the pencil marks mean that the anisotropic state is broken by the pencil and is converted to the isotropic state, so that the hardness of the pencil at the point where the pencil marks appear black causes the polarizer to lose anisotropy. It can be judged that it is a limit point.

As shown in Table 1, the surface of the liquid crystal coating layer according to the experimental example, the hardness of the pencil lead is black at 3H or more, it can be confirmed that the surface of the liquid crystal coating layer according to the comparative example is changed to black at 3B or more. Thereby, it can confirm that the liquid-crystal coating layer formed with the mammary chromonic liquid crystal composition by this invention is remarkably excellent in the surface hardness.

It has been described in detail above with reference to preferred experimental examples and comparative examples of the present invention. However, the scope of the present invention is not limited to the above experimental examples, it can be implemented in various forms of experimental examples within the scope of the appended claims. Without departing from the gist of the invention as claimed in the claims, any person skilled in the art to which the invention pertains is considered to be within the scope of the claims of the invention to the various possible modifications possible.

1A and 1B show the molecular structure and macrostructure of LCLC

2A is a view showing the structure of a unit molecular aggregate formed after polymerization is performed using a chromonic liquid crystal composition according to an embodiment of the present invention.

Figure 2b is a view showing a polarizing film formed by the composition

3 is a view sequentially showing an embodiment of a method of manufacturing the micro pattern polarizing device;

Figure 4 is a photograph of the liquid crystal coating layer formed by Experimental Example 1 observed with an optical microscope

5a and 5b is a photograph of the surface of the liquid crystal coating layer formed by the experimental and comparative examples, respectively

Claims (7)

A breast chromic liquid crystal composition comprising a basic chromonic liquid crystal compound having a basic functional group and an acid monomer having an acid functional group. The method of claim 1, The breast chromic liquid crystal composition according to claim 1, wherein the basic chromic liquid crystal compound is 5 to 40% by weight. The method of claim 1, The basic chromonic liquid crystal compound has a form in which a basic functional group is surrounded around a hydrophobic core made of aromatic molecules, and the basic functional group expresses nitrogen ions (N ⁺ ) when reacting with the acidic monomer. Mammary chromonic liquid crystal composition. The method of claim 1, The acidic functional group of the acidic monomer expresses at least one of carboxylate (COO ⁻ ) ion, phosphate ion (PO ₃ ⁻ ), and sulfonic acid ion (SO ₃ ⁻ ) upon reaction with the basic chromonic liquid crystal compound. Breast chromic liquid crystal composition. The method of claim 1, The mammary chromic liquid crystal composition is a mammary chromic liquid crystal composition, characterized in that it comprises a polymerization initiator consisting of at least one of a photoinitiator, a thermal initiator. The method of claim 5, The polymerization initiator is 0.01 to 10% by weight of the mammary chromonic liquid crystal composition, characterized in that the breast chromic liquid crystal composition. The method of claim 5, 100 wt% of the mammary chromic liquid crystal composition, 0.01 to 40 wt% of at least one of a nonionic vinyl monomer, water, an organic solvent, a crosslinking monomer, a leveling agent, a humectant, an ultraviolet stabilizer, and a conductive surfactant. A mammary chromonic liquid crystal composition characterized by the above-mentioned.

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