KR101056456B1 - Method for manufacturing polarizing film using naphthalene-based breast chromic liquid crystal composition - Google Patents

Abstract

The present invention relates to a method for producing a polarizing film using a naphthalene-based breast chromic liquid crystal composition, and a method for producing a polarizing film using a naphthalene-based breast chromic liquid crystal composition according to the present invention is represented by the following formula (1) Naphthalene-based mammary chromonic liquid crystal composition comprising a basic compound and a basic chromic liquid crystal compound having a basic functional group, an acidic monomer having an acidic functional group and a photoinitiator is formed using a shear force to form a short wavelength absorption layer on a base film or a long wavelength absorption layer. Coating step;

<Formula 1>

And a short wavelength curing step of curing the short wavelength absorption layer by photopolymerization.

According to the present invention, by using a naphthalene-based breast chromic liquid crystal composition having a new structure having a hydrophilic group in the molecule and absorbing the 400 to 450 nm region, it is possible to maintain excellent polarization characteristics in the long wavelength region while maintaining the excellent polarization characteristics in the short wavelength region (400 to 450 nm). There is an advantage that the light leakage is significantly improved.

Multi-layer structure, naphthalene system, chromic liquid crystal, polarizing film

Description

Method for manufacturing polarizing film using naphthalene-based breast chromic liquid crystal composition {METHOD OF MANUFACTURING POLARIZER FILM USING NAPHTHALENE LYOTROPIC LIQUID CRYSTAL COMPOSITON}

The present invention relates to a method for manufacturing a polarizing film using a naphthalene-based breast chromic liquid crystal composition, and more specifically, by using the naphthalene-based breast chromic liquid crystal composition, short wavelength light leakage in the range of 400 to 450 nm is improved, The present invention relates to a method of manufacturing a polarizing film using a naphthalene-based breast chromic liquid crystal composition capable of implementing a multilayer structure polarizing film by a simple process.

Among the types of lyotropic liquid crystals, lyotropic chromonic liquid crystals (hereinafter referred to as 'LCLC') have a uniform molecular arrangement due to hydrophilic group and disc-shaped mesogen structure in a molecule in a high concentration aqueous solution. As a material exhibiting liquid crystal properties, many studies have been conducted due to the possibility of application to electronic materials, optical materials, and photoelectric materials.

In particular, recently, in order to replace an optical film such as a polarizing plate manufactured by a conventional polyvinyl alcohol (PVA) stretching method, an optical film material in which a liquid crystal compound as a water-soluble or organic solvent-soluble organic dye has a planar molecular structure. Coated optical film is presented.

As a dye which shows a typical LCLC liquid crystal phase, a perylene type compound, an azo dye, an anthraquinone type dye, etc. are known. The optical properties of these LCLCs depend largely on the planar center structure of the dye and on the conjugation length. That is, the longer the conjugate length, the longer wavelength is absorbed, and the shorter the shorter wavelength is absorbed. Therefore, the development of chromic liquid crystals having various planar center structures is important for replacing optical films such as polarizing plates.

In particular, conventional LCLCs absorb wavelengths of 450 nm or more, and polarizers composed of a combination of liquid crystals have problems of light loss in a short wavelength region. For example, perylenebis (dicarboximide) (hereinafter referred to as 'PDI'), which is a perylene-based LCLC compound having the following chemical formula, is shown in the absorption bands of each wavelength band of FIG. It can be seen that the wavelength absorption in the 400 to 450nm region exhibits poor characteristics. As a result, when the polarizing film is manufactured with such an LCLC compound, as shown in the transmittance graph of FIG. 1B, the polarization efficiency represented by 'V' in the short wavelength region (400 to 450 nm) is poorly shown. . For reference, in FIG. 1B, T (0 °) is transmittance when the shearing axis of the oriented film is parallel to the polarization axis of incident light, and T (90 °) is transmittance when both are orthogonal. The average transmittance T ₀ is an average value of the parallel transmittance and the orthogonal transmittance, and can be determined as a measure of the transmittance of the unpolarized incident light. The polarization efficiency is a numerical value calculated by 100% x [T (0 °) -T (90 °)] / [T (0 °) + T (90 °)].

<Formula of PDI>

This phenomenon is seen in almost all known LCLC compounds such as Blue 27, Violet 20, Red 23, as well as PDI. Therefore, there is a need for an LCLC compound having a novel structure that absorbs a 400 to 450 nm region.

In addition, the polarizing film having a multi-layer structure by the LCLC compound is produced by the manufacturing method shown in Figs. 2a and 2b. In the manufacturing method illustrated in FIG. 2A, a poly cation 2 is coated on a base film 1 made of glass or mica, and a mammary chromic liquid crystal mixture 3 of blue27, violet20, red23, or the like is applied. After the aqueous solution of) is applied by the mechanical shearing force in the X-axis direction, and washing and removing unnecessary surplus substances and drying, the laminated structure of the chromonic liquid crystal electrostatically laminated on the dried film Since it remains intact, a polarizing film having a multilayer structure can be manufactured.

In the manufacturing method illustrated in FIG. 2B, a poly cation 2 is coated on a base film 1 made of glass or mica, and a blue27 aqueous solution 3 ′, which is a mammary chromic liquid crystal, is immersed in a dipping method. After being applied, and dried. The poly cation is again applied on the dried film, and blue27 aqueous solution (3 '), which is a breast chromic liquid crystal, is applied by an immersion method and then dried. By repeating this method, a multilayered liquid crystal laminate structure is obtained, and thus a polarizing film having a multilayer structure can be produced.

However, in the polarizing film manufacturing method of FIG. 2A, since the non-uniformity problem due to aggregation between the same structures is solved only when the mammary chromic liquid crystal mixture is similar in structure, the mammary chromic liquid crystal which can be prepared in the form of a homogeneous mixture. There is a problem that the type of is limited. In particular, when the polarizing film is manufactured using a known liquid crystal mixture of blue27, violet20, and red23 aqueous solution, there is a problem in that light leakage occurs in a short wavelength region of 400 to 450 nm, and a new chromonic liquid crystal is needed to solve this problem. In this case, the structure of the novel chromic liquid crystal required has a problem that compatibility with the existing liquid crystal mixture should be considered.

On the other hand, the polarizing film manufacturing method according to Figure 2b is a thin film of a few nm class by coating once, and in order to perform the role as a polarizing film, it is necessary to repeat coating several hundred times. This operation has to be repeated for chromic liquid crystals having different absorption wavelength bands, which causes problems in terms of productivity, such as a prolonged manufacturing process.

Therefore, a polarizing film having a uniform polarization function in the visible light wavelength range is required by using a mammary chromonic liquid crystal compound by a simple method, in particular, it is possible to cover a short wavelength region, and various kinds of mammary chromic liquid crystals There is a need for production of a usable chromogenic liquid crystal polarizing film.

The present invention is to solve the above problems, an object of the present invention, by using a naphthalene-based breast chromic liquid crystal composition of a novel structure having a hydrophilic group in the molecule and absorbing the 400 to 450nm region, excellent polarization characteristics in the long wavelength range It is an object of the present invention to provide a method of manufacturing a polarizing film in which light leakage in the short wavelength (400 to 450 nm) section is significantly improved while maintaining the ratio.

In addition, unlike the conventional method, since a naphthalene-based mammary chromic liquid crystal composition having a new structure having excellent compatibility with the existing liquid crystal compound is used, a multilayer structure can be simply implemented by only two coating processes, thereby producing a polarizing film having excellent productivity. It is an object to provide a method.

Method for producing a polarizing film using a naphthalene-based breast chromic liquid crystal composition according to the present invention for achieving the above object, a basic chromonic liquid crystal compound having a naphthalene compound and a basic functional group represented by the formula (1), acidic A short wavelength coating step of forming a short wavelength absorption layer on a base film or a long wavelength absorption layer by using a shearing force on a naphthalene-based breast chromic liquid crystal composition comprising an acidic monomer having a functional group and a photoinitiator;

<Formula 1>

And a short wavelength curing step of curing the short wavelength absorption layer by photopolymerization.

In addition, a basic chromogenic liquid crystal composition comprising a basic chromonic liquid crystal compound having a basic functional group, an acid monomer having an acid functional group and a photoinitiator; Or an acidic chromogenic liquid crystal composition comprising an acidic chromonic liquid crystal compound having an acidic functional group, a basic monomer having a basic functional group, and a photoinitiator; A long wavelength coating step of forming a long wavelength absorbing layer on the base film or the short wavelength absorbing layer using any one of a shear force; And a long wavelength curing step of curing the long wavelength absorption layer by photopolymerization.

In the short wavelength coating step, in the naphthalene-based breast chromic liquid crystal composition 100% by weight, the naphthalene-based breast chromic liquid crystal compound comprises 5 to 40% by weight of the liquid crystal composition between the solid crystal and the isotropic fluid It is preferable to exist with the characteristic of a liquid crystal.

Further, in the long wavelength coating step, in 100% by weight of the acidic mammary chromic liquid crystal composition, the acidic mammary chromic liquid crystal compound comprises 5 to 40% by weight, 100% of the basic mammary chromic liquid crystal composition In%, it is preferable that the basic mammary chromic liquid crystal compound contains 5 to 40% by weight in order for the liquid crystal composition to have the properties of the liquid crystal between the solid crystal and the isotropic fluid.

In the short wavelength coating step, the molar ratio of the naphthalene-based compound and the basic chromic liquid crystal compound is 0.8: 1 to 1: 1.5, and it is most preferable to have both the characteristics as the liquid crystal and the short wavelength absorption characteristic.

According to the manufacturing method of the multilayer structure polarizing film using the naphthalene type | mold breast chromic liquid crystal composition which concerns on this invention, by using the naphthalene type | mold breast chromic liquid crystal composition of the novel structure which has a hydrophilic group in a molecule and absorbs 400-450 nm area | region In the long wavelength region, the light loss in the short wavelength region (400 to 450 nm) is significantly improved while maintaining excellent polarization characteristics.

In addition, unlike the conventional method, since the naphthalene-based mammary chromonic liquid crystal composition having a new structure having excellent compatibility with the existing liquid crystal compound is used, the multilayer structure can be simply implemented by only two coating processes, and thus the productivity is excellent.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings with respect to a method for producing a polarizing film using a naphthalene-based breast chromic liquid crystal composition according to the present invention.

Figure 3 is a flow chart sequentially showing a manufacturing method of a polarizing film using a naphthalene-based breast chromic liquid crystal composition of the present invention. As shown in Figure 3, the method for producing a polarizing film using a naphthalene-based breast chromic liquid crystal composition according to the present invention is a short wavelength coating step (S10), a short wavelength curing step (S20), a long wavelength coating step (S30), a long wavelength It comprises a curing step (S40). In addition, Fig. 4 shows a simple schematic diagram of a method for producing a polarizing film using the naphthalene-based breast chromic liquid crystal composition of the present invention. Hereinafter, a method of manufacturing a polarizing film using the naphthalene-based breast chromic liquid crystal composition of the present invention shown in FIGS. 3 and 4 will be described in detail.

The short wavelength coating step (S10) is a shearing force of the naphthalene-based breast chromic liquid crystal composition comprising a naphthalene compound represented by the following formula (1), a basic chromonic liquid crystal compound having a basic functional group, an acid monomer having an acid functional group and a photoinitiator. Forming a second coating layer on the first coating layer by using the second coating layer. The long wavelength coating step (S30) is different in that the naphthalene-based compound is included, and the other content is the same as the long wavelength coating step (S30) described below. In addition, a basic chromonic liquid crystal compound and an acidic monomer are as described below. Hereinafter, the difference will be described.

<Formula 1>

로 표현되며,Specifically,

Represented by

(Me는 메틸기를 포함한 알킬기) 또는 HCOO 중 어느 하나이다. In Formula 1, R is an alkyl group or a hydrogen atom, A is a halogen element,

(Me is an alkyl group including a methyl group) or HCOO.

Hereinafter, the naphthalene compound represented by Chemical Formula 1 will be described.

The structure has an asymmetric form, unlike the structure of a general LCLC compound. Accordingly, the naphthalene compound includes a diamine group represented on the left side and a benzimidazole represented on the right side, as shown in the formula (1). Thus, the naphthalene compound includes an amine group on one side, It has hydrophilic groups, such as a diamine group, and introduces the benzimidazole structure which extends conjugation length to the other, and exhibits the effect which absorbs the short wavelength region of 400-450 nm. The manufacturing method of the naphthalene type compound which concerns on this invention which has such a structure is as follows.

1 mole of 1,4,5,8-naphthalene tetracarboxylic acid 1,8-monohydride (hereinafter referred to as 'naphthalene monoanhydride') represented by the following Chemical Formula 2-1 was added to a flask containing distilled water. It disperse | distributes and it adds, and adds 1-10 mol of N, N- diethyl ethylenediamine aqueous solution represented by General formula (3), and makes it react with stirring.

<Formula 2-1>

<Formula 3>

Here, since 1 molecule of N, N-diethyl ethylenediamine of Formula 3 is reacted per molecule of naphthalene monoanhydride of Formula 2-1, at least 1 mol of compound of Formula 3 should be reacted per mole of compound of Formula 2-1. Increasing the relative molar ratio of the compound of formula 3 to the compound of formula 2-1 increases the reaction yield. However, more than 10 moles of the compound of Formula 3 per mole of the compound of Formula 2-1 is not preferable in terms of separation and purification. The reaction proceeds at 20 ° C. to 150 ° C. for 2 hours to 3 days. If the reaction temperature is less than 20 ° C, it is not preferable because the reaction yield is low. If the reaction temperature is higher than 150 ° C, decomposition of the compound is not preferable. If the reaction time is less than 2 hours, the yield is unfavorable in that the yield is too low, and if it exceeds 3 days, the productivity is not preferable. At the end of the reaction, the reaction is cooled to room temperature and about 1 L of acetone is added to the reaction. The obtained crystals are filtered and washed several times with acetone or a polar organic solvent such as methanol and ethanol. The crystals are collected and dried in a vacuum oven, for example, at 50 ° C. to 120 ° C. for 1 to 7 days.

Next, the product represented by the formula (2-2) obtained by the above method (1,4,5,8-naphthalene tetracarboxylic acid diethylaminoethyl 1,8-imide (hereinafter referred to as 'naphthalene carboxylic acid imide') .) After dissolving 1 mole in glacial acetic acid, 1 to 5 moles of ortho-phenylene diamine represented by the formula (4) are added, and the reaction is stirred after 10 minutes to 1 hour at O ° C.

<Formula 2-2>

<Formula 4>

The reaction proceeds at 80 ° C. to 150 ° C. for 3 hours to 4 days. If the reaction temperature is less than 80 ° C, it is not preferable because the reaction yield is low, and if the reaction temperature is higher than 150 ° C, addition reaction is not preferable. If the reaction time is less than 3 hours, the yield is too low, which is not preferable, and if it exceeds 4 days, the productivity is not preferable. At the end of the reaction, the reaction is cooled to room temperature and about 1 L of ether is added to the reaction. The obtained crystals are filtered and washed several times with a polar organic solvent such as ether. The crystals are collected and dried in a vacuum oven, for example at 50 ° C. to 120 ° C. for 1 to 7 days. The drying conditions are not particularly limited as long as all solvents and the like can be removed without affecting the physical properties of the compound of Formula 1, but it is preferable to dry them in the above temperature and time range in consideration of these matters.

However, such a naphthalene compound has a crystal structure in itself, and thus it is difficult to be used alone as a liquid crystal thin film. Therefore, in order to use it as a liquid crystal thin film, it is necessary to convert it into a liquid crystal phase. To this end, the present invention solves the above problem by mixing a common LCLC having a symmetric structure.

That is, the naphthalene-type mammary chromonic liquid crystal composition according to the present invention further comprises a mammary chromonic liquid crystal (LCLC) compound in the naphthalene-based compound. Here, the LCLC compound to be used is not particularly limited as long as it can form a liquid crystal phase by mixing with a naphthalene compound of formula (1), but it is preferable to mix a basic chromonic liquid crystal compound having a basic functional group. This is because, since the hydrophilic functional group bonded to the naphthalene compound is an amine group expressing a cation such as nitrogen ion (N ⁺ ) in the solution, when the acidic chromonic liquid crystal compound having an anionic functional group is mixed in the formation of the mixture This is because a non-uniformity problem may occur due to the aggregation between the compounds due to the reaction of the functional groups. Therefore, the basic chromonic liquid crystal compound including the basic functional group is preferably mixed with the functional group of the naphthalene compound. However, as long as it is excellent in miscibility with the said naphthalene type compound and can form a liquid crystal phase naturally among acidic chromic liquid crystal compounds, its use is not restrict | limited.

Further, among the acidic or basic chromonic liquid crystal compounds, LCLC having a central molecule having the same size or larger than the central molecule of the naphthalene compound according to the present invention is more preferably applied. When the LCLC has a smaller central molecule than the central molecule of the crystalline naphthalene compound, a bulky hydrophilic functional group of the LCLC is placed on the central molecule structure of the naphthalene compound when the molecules are stacked, and the center between the naphthalene compound and the LCLC is centered. This is because the self-assembly caused by the π-π interaction between molecules is hindered, and the crystals of the naphthalene compound are highly likely to precipitate.

In addition, the mixture of the naphthalene-based compound and the LCLC compound should have both liquid crystal properties and short wavelength absorption characteristics. In order to satisfy these conditions, the content of both must be adjusted at an appropriate level. The content ratio of such naphthalene compound and LCLC compound is 0.8: 1 to 1: 1.5, more preferably 1: 1 to 1: 1.3 based on the molar ratio. The naphthalene-based breast chromic liquid crystal composition according to the present invention for forming a liquid crystal thin film is basically a solvent 70 formed by mixing 2-30% by weight of the mixture of the naphthalene-based compound and the LCLC compound with water or an organic solvent alone or in a mixture. It comprises to 98% by weight.

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

As described above, the naphthalene-based LCLC composition according to the present invention based on a naphthalene-based compound-general LCLC compound-solvent has a characteristic of absorbing short wavelengths in the 400 to 450 nm region, thereby manufacturing an optical film such as a polarizing film. When the LCLC layer is laminated in a multi-layer film, one layer is formed of a general LCLC composition absorbing a long wavelength of 500 to 700nm, and the other layer is formed of a naphthalene-based LCLC composition layer according to the present invention It is possible to obtain an optical film having excellent efficiency of absorbing all regions of the visible light spectrum.

For example, as shown in FIG. 5, for example, a poly anion of the following formula is applied onto a base film 1 made of glass or mica, and an aqueous solution of an LCLC composition comprising an LCLC dye. After application orientation by mechanical shearing in the X-axis direction, the first LCLC layer 20 for absorbing long wavelengths is laminated by washing, removing and drying unnecessary surplus substances, and again on the first LCLC layer 20. After the polyanion is applied, the naphthalene-based LCLC composition according to the present invention, which absorbs short wavelengths, is applied / oriented / dried in the same manner as in the first LCLC layer 20 formation to form a second LCLC layer 30 and laminated. In addition, an optical film in which a two-layer laminated structure of chromonic liquid crystals electrostatically stacked on the dried film is maintained intact is obtained. In the present embodiment, a two-layer lamination method is illustrated, but by repeatedly laminating a layer made of a polyion layer and a suitable LCLC composition on the second LCLC layer 30, an optical film having a multilayer structure may be manufactured. In another method, in forming the LCLC layers 20 and 30, the LCLC dye aqueous solution or composition may be applied by a dipping method and then dried. That is, if the composition containing a well-known LCLC compound and the naphthalene type LCLC composition by this invention are alternately repeatedly laminated | stacked and an optical film is obtained, it can use without particular limitation.

<Chemical Formula of Polyanion>

<Chemical Formula of Polyanion>

The short wavelength curing step (S20) is a step of curing the short wavelength absorption layer by photopolymerization, and the method is the same as the following long wavelength curing step (S40). The short wavelength coating step (S10), the short wavelength curing step (S20) and the following long wavelength coating step (S30), the long wavelength curing step (S40) may be reversed, the order is not absolute order. In addition, the short wavelength step and the long wavelength step may be repeated to form a multilayer structure.

The long wavelength coating step (S30) comprises a basic chromic liquid crystal composition comprising a basic chromic liquid crystal compound having a basic functional group, an acid monomer having an acid functional group, and a photoinitiator; Or an acidic chromogenic liquid crystal composition comprising an acidic chromonic liquid crystal compound having an acidic functional group, a basic monomer having a basic functional group, and a photoinitiator; One of the steps of forming a long wavelength absorption layer on the base film or the short wavelength absorption layer using a shear force.

In the present invention, since the conventional mammary chromic liquid crystal is manufactured by using water as a solvent (Water-based), in order to solve problems such as aggregation between the mammary chromic liquid crystal in implementing a multilayer structure, the monomers described below By developing the breast-based chromic liquid crystal composition based on the above, the polarizing film having a multi-layer structure can be manufactured by a simple process by allowing crosslinking while maintaining the liquid crystal phase.

In addition, an anion of an acidic functional group or a basic functional group surrounding an aromatic hydrophobic core of a chromonic liquid crystal compound and a cation of a basic monomer as a counter-ion or an anion of an acidic monomer interact with each other to form a new functional group. In the case of producing the mammary chromic liquid crystal and curing the mammary chromic liquid crystal composition, the bond between the molecular aggregates and the molecular aggregates forming a laminated structure in the liquid crystal dye by polymerization by the new functional group and The bonding between the base films can be strengthened, and thus the excellent mechanical, optical and electrical properties of the formed film can be achieved.

In addition, the acidic mammary chromic liquid crystal composition or the basic mammary chromic liquid crystal composition includes a photoinitiator to cure through photopolymerization using ultraviolet rays or the like.

The coating method in the long wavelength step (S30) is spin coating, dip coating, flow coating, rod coating, spray coating, slot die coating (slot die coating, roll coating, gravure coating, micro-gravure coating, etc. can be used, but slot die coating or rod coating because shear force is most effective for orientation. It is most preferable to use the method. Through this, the axis of the chromonic liquid crystal molecules is oriented perpendicular to the direction in which the shear force is applied.

In addition, an anisotropic film such as glass, mica, or triacetyl cellulose (TAC) may be used as the base film, and a polyester such as polyethylene terephthalate (PET) or polyethylene naphthalate may be used as a hydrophobic transparent resin film. General light transmitting resins such as polymers, acrylic polymers such as polymethyl methacrylate (PMMA), styrene polymers such as polystyrene and acrylonitrile-styrene copolymers, and polycarbonate polymers can be used without limitation.

Hereinafter, the configuration of the mammary chromic liquid crystal composition used in the present invention will be described.

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

(Me는 메틸기를 포함한 알킬기) 또는 HCOO 중 어느 하나이며, X는 수소 또는 할로겐 원자(Cl, Br 등)이다.In Formulas I-1 to I-9, 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.).

In addition, the term “acidic functional group” herein refers to a functional group directly contacting an aromatic ring, and is not particularly limited as long as it is an acidic functional group, but the carboxylate (COO ⁻ ) ion mainly reacts with a basic monomer described below. Salts, ester groups, carboxyl groups of COO ^{-to be} expressed; Phosphate, phosphine group, phosphate group, phosphonic acid group in which phosphate ions (PO ₃ ⁻ ) are expressed during the reaction; And sulfonic acid and sulfonic acid groups in which sulfonic acid ions (SO ₃ ⁻ ) are expressed during the reaction. The acidic functional group is generally present in the form of an ester group, a phosphine group, a sulfonic acid group, or the like as described above, or the carboxylate (COO ⁻ ) ion and the like, H ⁺ , NH ₄ ⁺ , Li ⁺ , Na ⁺ , K ⁺ Other cations, such as, Cs ⁺ , are present in the form of salts, and when reacted with a basic monomer described later, the anion is exposed to bond with a cation of an acidic functional group of the monomer.

Specific examples of such acidic chromonic liquid crystal compounds are as shown in the following formulas (II-1) to (II-6). However, the acid chromic liquid crystal compound is not limited to the following chemical formula.

Formula II-1

Formula II-2

Formula II-3

Formula II-4

(Formula II-5)

Formula II-6

In Formulas II-1 to II-6, R is an alkyl group or a hydrogen atom, n = 1 to 3, X is a hydrogen or halogen atom, Me is an alkyl group including a methyl group, C is H +, NH4 +, Li +, Na + K +, and other cations.

It is effective that the basic or acidic chromonic liquid crystal compound is contained in an amount of 5 to 40% by weight, preferably 10 to 30% by weight, based on the basic or acidic mastogenic chromonic liquid crystal composition. The content range of the basic or acidic chromonic liquid crystal compound is a preferred range for the liquid crystal composition to exist with the characteristics of the liquid crystal between the solid crystal and the isotropic fluid.

I. Acid and Basic 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, an acidic or basic monomer is used instead of an aqueous solution, and in the case of an acidic monomer, respectively, a basic functional group of the basic chromonic liquid crystal compound, and a basic monomer, an acidic functional group and a strong ionic bond of the acidic chromonic liquid crystal compound. The polymerization was performed in the state in which the bonded liquid crystal molecules were laminated and aligned, thereby inducing strong bonding between the molecules, thereby obtaining a strong cohesion and high surface hardness between the liquid crystal molecules.

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, sulfopropyl acrylate or methacrylate or other water soluble forms thereof or other polymerizable carboxylic acid or sulfonic acid, 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 the same as the formulas (III-1) to (III-6).

(Formula III-1)

(Formula III-2)

Formula III-3

(Formula III-4)

Formula III-5

In the above formula, n = 0 to 3.

(Formula III-6)

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

In addition, the "basic monomer" used in the present invention is not particularly limited as long as it is a monomer having a basic functional group corresponding to the acidic functional group of the acidic chromonic liquid crystal compound. It refers to a functional group which expresses a nitrogen ion (N ⁺ ) such as a cation, mainly an amine group, an imine group, an amide group, an azide group, a nitrate group or an ammonium group during the reaction. Representative basic monomers include dialkylaminoalkylacrylates and methacrylates and quaternary or acid salts thereof (eg DMAEA, MAQ), dialkylaminoalkylacrylamides and methacrylamides and quaternary or acid salts thereof, N, N Diallylamine and its ammonium salt, diaryldimethylammonium chloride (DADMAC), Mannich products, and the like, but are not limited to these. Alkyl groups are generally C1-4 alkyl.

In addition, the basic monomers used in the present invention are as shown in the following formula IV-1 to IV-5.

Formula IV-1

Formula IV-2

Formula IV-3

Formula IV-4

Formula IV-5

(3) photoinitiator

In addition to the said basic chromonic liquid crystal compound and an acidic monomer, the said mammary chromic liquid crystal composition contains the photoinitiator for easy superposition | polymerization after orientation.

The photoinitiator used in the present invention is used in the case of photopolymerizing the composition by ultraviolet light or the like, specifically, diethoxyacetphenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, benzo Benzoin ethers such as phosphorus isobutyl ether, benzophenone, methyl o-benzoylbenzoate, 2, 4, 6-trimethylbenzoyldiphenylbenzoyl oxide and the like can be used alone or 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.

The content of the photoinitiator is preferably in the range of 0.01% by weight to 10% by weight in 100% by weight of the naphthalene-based mammary chromic liquid crystal composition or the acidic mammary chromic liquid crystal composition or the basic mammary chromic liquid crystal composition. More preferably, it is 0.5 to 5 weight%. If the content of the photoinitiator is less than 0.1% by weight, it is difficult to obtain a polymerization effect, and if the content of the photoinitiator is more than 10% by weight, too much photoinitiator is added as compared to the photopolymerization effect, thereby degrading economic efficiency.

(4) additives and solvents

In addition, the breast chromic liquid crystal composition used in the present invention may further include an additive, if necessary, and may be added a solvent such as an organic solvent and water in order to facilitate viscosity adjustment. 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 such as CH ₂ = C (X) Z or CH ₂ = CH-OC (O) R. Wherein 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; R ¹ are each independently C ₁ -C ₃₀ alkyl, hydroxy-substituted C ₂ -C ₃₀ alkyl or halogen-substituted C ₁ - is a 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), isopropyl styrene, p-chlorostyrene and the like; Vinyl esters such as vinyl acetate, vinyl neodecanoate, and the like, but are not limited to these.

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 and the like and combinations thereof, but are 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 active compound. Halogen compounds, isoxazoles, and dialdehyde starches; These can be used individually or in combination of 2 or more types.

Preferably two such as polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, phenoxyethyldi (meth) acrylate, divinylbenzene, diallyl ether, di (meth) acrylamide ideal 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.

The addition amount of such an additive and a solvent is to add 0.01 to 40% by weight relative to 100% by weight of the naphthalene-based breast chromic liquid crystal composition, the acidic breast chromic liquid crystal composition, or the basic mammary chromic liquid crystal composition. Preferably, more preferably, 0.1 to 35% by 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.

Long wavelength curing step (S40) is a step of curing the long wavelength absorption layer through a polymerization reaction by irradiating light toward the long wavelength absorption layer. Here, light is usually infrared rays, and the long wavelength absorption layer is cured together with polymerization through light irradiation. It is preferable that the irradiation amount of the said light is 10 mJ / cm <2> -30mJ / cm <2>, Most preferably, it is 15-25 mJ / cm <2>. If the irradiation amount of light is less than 10mJ / cm 2, the polymerization reaction and curing does not occur sufficiently, and when it exceeds 30mJ / cm 2 there is a problem that the polymerization reaction occurs excessively.

Hereinafter, through an embodiment of the manufacturing method of the polarizing film using a naphthalene-based breast chromic liquid crystal composition according to the present invention, to demonstrate the effect of the present invention.

Example 1 <Short wavelength absorption range of naphthalene compound>

After dissolving the naphthalene compound of Formula 1 in a 16.5 N formic acid (HCOOH) aqueous solution, the optical properties of the solution were measured and displayed graphically, compared to the conventional mammary chromic liquid crystal composition shown in FIG. As shown in FIG. 7, it can be seen that the absorption in the wavelength region of 400 to 450 nm is excellent.

Example 2 < Preparation of naphthalene-based basic mammary chromic liquid crystal composition>

The primary mixture was prepared by mixing 0.05 g of the naphthalene compound of Formula 1 and 0.05 g of Red 2304 (manufactured by Optiva) represented by Formula I-2 as a basic chromonic liquid crystal compound.

The primary mixture thus obtained was dissolved by adding 10% by weight in 16.5 N formic acid (HCOOH) aqueous solution, and then taken as a result of photographing a polarization microscope. As shown in FIG. 8, it was confirmed that the primary mixture was changed into a liquid crystal phase.

Example 3 <Manufacturing Polarizing Film of Multi-Layer Structure>

As a basic chromonic liquid crystal compound on a glass substrate, 0.05 g of each of the general formulas I-4 and I-6 and a reactive monomer, 0.05 ml of acrylic acid of the general formula III-3 and 0.0025 g of a photoinitiator (Irgacure 907, manufactured by Ciba) After mixing and dropping, coating by shear force using a rod, and then irradiated with light of 20mJ / cm ² using a metal halide lamp to cure the applied liquid crystal coating film, to obtain a first liquid crystal coating film.

In addition, 0.05 g of Red 2304 (manufactured by Optiva) represented by Chemical Formula I-2, 0.05 g of Chemical Formula 1, and a reactive monomer are acryl of Chemical Formula III-3 on the first liquid crystal coating film as a basic chromonic liquid crystal compound. 0.05 ml of acid and 0.0025 g of photoinitiator (Irgacure 907, manufactured by Ciba) were mixed and added dropwise, coated by shear force using a rod, and then irradiated with light of 20 mJ / cm ² using a metal halide lamp. The obtained liquid crystal coating film was hardened and the 2nd liquid crystal coating film was obtained. Thus, a polarizing film having a two-layer structure of the present invention was prepared.

The transmittance and polarization efficiency for the two-layer polarizing film of the present invention thus obtained were measured as follows, and the results are shown in FIG. 9.

Transmittance

The transmittance was measured using a spectrophotometer (V-7100, manufactured by Jasco), and obtained using the following formula.

Permeability (%) = (I _out / I _in ) * 100

Where I _in is incident light and I _out is transmitted light,

The parallel transmittance T (0 °) is the transmittance (%) when the shearing axis of the oriented film is parallel to the polarization axis of the incident light,

Orthogonal transmittance T (90 °) is the transmittance (%) when the shearing axis of the oriented film is orthogonal to the polarization axis of the incident light,

The mean transmittance (T _mean ) is an average value of the parallel transmittance and the orthogonal transmittance, and was calculated using the following equation.

Average transmittance (T _mean ) = [T (0 °) + T (90 °)] / 2 × 100 (%)

Polarization Efficiency (V)

Polarization efficiency was calculated | required using the following formula.

Polarization degree (V) = [T (0 °)-T (90 °)] / [T (0 °) + T (90 °)] × 100 (%)

As shown in Figure 9, according to the liquid crystal polarizing film prepared according to the preparation example, when the polarization axis of the incident light is orthogonal to the shear force direction, under the influence of the naphthalene compound of the formula (1) contained in the raw material composition, 400 to 450nm Absorption characteristics for short wavelength visible light are remarkably excellent, and on the contrary, when the polarization axis of incident light is parallel to the shear force, only weak absorption occurs in the short wavelength visible light region. This indicates that the long axes of the LCLC composition molecules on the base film were mostly oriented perpendicular to the shear force direction.

In addition, the orthogonal transmittance is shorter than the result of FIG. 8 using the conventional mammary chromonic liquid crystal composition and the result of FIG. All the wavelengths were uniformly low, showing excellent absorption characteristics in the entire visible light region, and the polarization efficiencies also showed excellent characteristics of more than 80%.

The foregoing has been described in detail with reference to preferred embodiments of the present invention. However, the scope of the present invention is not limited to the above embodiment, but may be embodied 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 are graphs of transmittances in the visible light absorption spectrum and visible light wavelength region of conventionally known LCLC compounds, respectively.

2a and 2b is a multi-layered polarizing film using a LCLC compound known in the art, respectively

Figure 3 is a flow chart sequentially showing a manufacturing method of a polarizing film using a naphthalene-based breast chromic liquid crystal composition of the present invention

Figure 4 is a schematic diagram showing a manufacturing method of a polarizing film using a naphthalene-based breast chromic liquid crystal composition of the present invention.

5 is a cross-sectional view of a multilayer polarizing film manufactured by a method of manufacturing a polarizing film using a naphthalene-based breast chromic liquid crystal composition of the present invention.

6 is a graph of transmittance in the visible light wavelength region of the conventional mammary chromonic liquid crystal composition

7 is a graph of transmittance in the visible light wavelength region of the naphthalene-based breast chromic liquid crystal composition of the present invention

8 is a polarization micrograph of the naphthalene-based breast chromic liquid crystal composition of the present invention

Figure 9 is a graph of transmittance in the visible light wavelength region of the polarizing film prepared by the method for producing a polarizing film using the naphthalene-based breast chromic liquid crystal composition of the present invention

Claims (5)

A short wavelength absorption layer on a base film using a shearing force to a naphthalene-based mammary chromonic liquid crystal composition comprising a naphthalene compound represented by the following formula (1), a basic chromonic liquid crystal compound having a basic functional group, an acid monomer having an acid functional group, and a photoinitiator. Short wavelength coating step of forming a; <Formula 1>

And a short wavelength curing step of curing the short wavelength absorbing layer by photopolymerization. The method of claim 1, A basic chromogenic liquid crystal composition comprising a basic chromonic liquid crystal compound having a basic functional group, an acid monomer having an acid functional group, and a photoinitiator; Or an acidic chromogenic liquid crystal composition comprising an acidic chromonic liquid crystal compound having an acidic functional group, a basic monomer having a basic functional group, and a photoinitiator; A long wavelength coating step of forming a long wavelength absorbing layer on the base film or the short wavelength absorbing layer using any one of a shear force; And a long wavelength curing step of curing the long wavelength absorption layer by photopolymerization. 2. The method of claim 1, further comprising a naphthalene-based breast chromic liquid crystal composition. The method according to claim 1 or 2, In the short wavelength coating step, in the naphthalene-based breast chromic liquid crystal composition 100% by weight, the naphthalene-based breast chromic liquid crystal compound is 5 to 40% by weight of the naphthalene-based breast chromic liquid crystal composition Method for producing a polarizing film used. 3. The method of claim 2, In the long wavelength coating step, in the 100% by weight of the acidic mammary chromic liquid crystal composition, the acidic mammary chromic liquid crystal compound is 5 to 40% by weight, in 100% by weight of the basic mammary chromic liquid crystal composition, The basic mammary chromonic liquid crystal compound is a manufacturing method of a polarizing film using a naphthalene-based mammary chromonic liquid crystal composition, characterized in that 5 to 40% by weight. The method according to claim 1 or 2, In the short wavelength coating step, the molar ratio of the naphthalene-based compound and the basic chromonic liquid crystal compound is 0.8: 1 to 1: 1.5 method of manufacturing a polarizing film using a naphthalene-based breast chromic liquid crystal composition.

Images