KR102089807B1 - Composition for forming polarizing film and polarizing film - Google Patents

Abstract

An object of the present invention is to provide a composition for forming a polarizing film capable of producing a thin and highly transparent polarizing film, and a polarizing film formed from the composition for forming a polarizing film.
As a composition for forming a polarizing film which contains a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a photopolymerization initiator and a solvent, and which satisfies the following requirements (A) and (B), and a composition for forming the polarizing film Provided is a polarizing film to be formed.
(A) The polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound both have polymerizable groups;
(B) The polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing film does not form a phase separation state, but exhibits a nematic liquid crystal phase and a smectic liquid crystal phase.

Description

Composition for polarizing film formation and polarizing film {COMPOSITION FOR FORMING POLARIZING FILM AND POLARIZING FILM}

The present invention relates to a composition for forming a polarizing film, a polarizing film produced from the composition for forming a polarizing film, a manufacturing method, and the like.

In recent liquid crystal display devices, the thinning thereof is strongly demanded, and accordingly, the polarizer used in the liquid crystal display devices is also required to be thinner. In order to realize a thinner polarizer, it has been studied that a polarizing film used in a liquid crystal display device is formed of a composition containing a polymerizable liquid crystal compound instead of a film made of polyvinyl alcohol dyed with iodine.

As a polarizing film formed from a composition containing a polymerizable liquid crystal compound, for example, Patent Document 1 discloses a polarizing film composed only of a polymerizable smectic liquid crystal compound, a dichroic dye, a photopolymerization initiator, and an inhibitor, and also a patent document. In 2, a polarizing film comprising only a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator, an inhibitor, a gelling agent, and a solvent is disclosed.

[Patent Document 1] Japanese Patent No. 4719156 [Patent Document 2] Japanese Patent Publication No. 2008-547062

However, further thinning and high transparency of the polarizing film have been required.

An object of the present invention is to provide a composition for forming a polarizing film capable of producing a thin and highly transparent polarizing film, and a polarizing film formed from the composition for forming a polarizing film.

The present invention provides the following invention.

[1] A composition for forming a polarizing film that contains a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a polymerization initiator, and a solvent and satisfies the following requirements (A) and (B).

(A) The polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound both have polymerizable groups;

(B) The polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing film does not form a phase separation state, and exhibits a nematic liquid crystal phase and a smectic liquid crystal phase [Requirements of (A) and (B) Each of hereinafter referred to as "(requirement A)" and "(requirement B)".

[2] The composition for forming a polarizing film according to [1], wherein the polymerizable liquid crystal compound is a compound represented by the following formula (1).

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (1)

(In the formula, X ¹ , X ² and X ³ each independently represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, X ¹ , At least one of X ² and X ³ is a 1,4-phenylene group which may have a substituent -CH ₂ -constituting the cyclohexane-1,4-diyl group is -O-, -S- or -NR It may be substituted with-R represents an alkyl group or a phenyl group having 1 to 6 carbon atoms Y ¹ and Y ² independently of each other -CH ₂ CH _2- , -CH ₂ O-, -COO-, -OCOO-, Represents ^a single bond, -N = N-, -CR ^a = CR ^b- , -C≡C- or -CR ^a = N- R ^a and R ^b independently of each other are a hydrogen atom or an alkyl group having 1 to 4 carbon atoms U ¹ represents a hydrogen atom or a polymerizable group U ² represents a polymerizable group W ¹ and W ² independently of each other represent a single bond, -O-, -S-, -COO- or -OCOO- V ¹ and V ² independently of one another have a substituent. It may represent an alkanediyl group having 1 to 20 carbon atoms, and -CH ₂ -constituting the alkanediyl group may be substituted with -O-, -S- or -NH-.)

[3] The composition for forming a polarizing film according to [1] or [2], wherein the polymerizable non-liquid crystal compound is a monofunctional acrylate or a polyfunctional acrylate.

[4] The polymerizable group of the polymerizable liquid crystal compound and the polymerizable group of the polymerizable non-liquid crystal compound are each independently an acryloyloxy group (CH ₂ = CHCOO-) or a methacryloyloxy group (CH ₂ = C (CH ₃ ) A composition for forming a polarizing film according to any one of [1] to [3], which is COO-).

[5] The composition for forming a polarizing film according to any one of [1] to [4], wherein the polymerizable group of the polymerizable liquid crystal compound and the polymerizable group of the polymerizable non-liquid crystal compound are the same.

[6] The polarizing film according to any one of [1] to [5], wherein the polymerizable liquid crystal compound has 1 to 2 polymerizable groups in the molecule, and the polymerizable non-liquid crystal compound has 2 to 6 polymerizable groups in the molecule. Dragon composition.

[7] The composition for forming a polarizing film according to any one of [1] to [6], wherein the content of the polymerizable non-liquid crystal compound is 3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable liquid crystal compound.

[8] A method for producing a polarizing film having the following steps (I), (II) and (III).

(I) A step of applying the composition for forming a polarizing film according to any one of [1] to [7] on a substrate or on an alignment film formed on a substrate, and removing a solvent to form a coating film;

(II) a step of bringing the polymerizable liquid crystal compound contained in the coating film formed in (I) into a smectic liquid crystal phase;

(III) The process of copolymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound in the coating film in which the polymerizable liquid crystal compound formed in (II) is in a smectic liquid crystal phase state.

[9] The method for producing a polarizing film according to [8], wherein the substrate is a transparent substrate on which an orientation treatment has been performed.

[10] Step (I-1) and step (I-) of heating until the polymerizable liquid crystal compound contained in the coating film formed in step (I) exhibits a nematic liquid crystal phase in step (II). [8] or [8] which is a process having a step (I-2) of cooling the coating film in which the polymerizable liquid crystal compound formed in 1) is in a nematic liquid crystal phase until the polymerizable liquid crystal compound exhibits a smectic liquid crystal phase. The manufacturing method of the polarizing film as described in 9].

[11] A polarizing film produced by the production method according to any one of [8] to [10].

[12] The polarizing film according to [11], which shows a black peak in diffraction measurement by X-rays.

[13] A display device comprising the polarizing film according to [11] or [12].

According to the composition for forming a polarizing film of the present invention, a thin and highly transparent polarizing film can be produced.

1 is a schematic view showing a main part of a method for continuously producing a polarizing film of the present invention (roll-to-roll type).
2 is a schematic diagram showing a cross-sectional configuration of a liquid crystal display using a polarizer including the polarizing film of the present invention.
3 is a schematic view showing a layer sequence of a polarizer including the polarizing film of the present invention installed on a liquid crystal display device.
4 is a schematic view showing a layer sequence of a polarizer including the polarizing film of the present invention installed on a liquid crystal display device.
5 is a schematic view showing the configuration of a liquid crystal display (in-cell type) using a polarizer including the polarizing film of the present invention.
6 is a schematic cross-sectional view of a circular polarizing plate including the polarizing film of the present invention.
7 is a schematic view of a method for continuously manufacturing a circular polarizing plate including the polarizing film of the present invention.
8 is a schematic view showing the configuration of an EL display device using a circular polarizing plate including the polarizing film of the present invention.
9 is a schematic view showing a layer sequence of an original polarizing plate including the polarizing film of the present invention installed on an EL display device.
10 is a schematic view showing the configuration of an EL display device using a circular polarizing plate including the polarizing film of the present invention.
11 is a schematic view showing the configuration of a projection type liquid crystal display device using a polarizer including the polarizing film of the present invention.

<Polarizing film forming composition>

The composition for forming a polarizing film of the present invention (hereinafter referred to as "the present composition" in some cases) contains a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a polymerization initiator, and a solvent. The polarizing film (hereinafter referred to as "the present polarizing film" in some cases) formed by the manufacturing method described later with the present composition is not only suitable for a liquid crystal display device, but also a circular polarizer suitable for an organic EL display device (hereinafter, a case) In accordance with this, it is possible to manufacture the &quot; original polarizing plate &quot;). First, the composition will be described.

<Polymerizable liquid crystal compound>

The polymerizable liquid crystal compound of the present invention is a liquid crystal compound having a polymerizable group and having a characteristic of exhibiting a nematic liquid crystal phase and a smectic liquid crystal phase without forming a phase separation state in the coating film formed of the composition. .

Whether or not the coating film formed from the present composition satisfies (Requirement B) can be confirmed, for example, as follows. The present composition is applied to a glass substrate, and the solvent is removed by subjecting the applied composition to heat treatment and / or reduced pressure treatment under conditions in which the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound do not polymerize. Subsequently, the coating film formed on the glass substrate is heated, and it is confirmed whether or not the polymerizable liquid crystal compound contained in the coating film is not phase-separated and exhibits a nematic liquid crystal phase. Subsequently, the heated coating film is gradually cooled, and it is confirmed whether or not the polymerizable liquid crystal compound contained in the coating film is not phase-separated and exhibits a smectic liquid crystal phase. The nematic liquid crystal phase and the smectic liquid crystal phase can be confirmed by, for example, texture observation with a polarization microscope, X-ray diffraction measurement, or differential scanning calorimetry. The phase separation can be confirmed by, for example, surface observation using various microscopes or scattering degree measurement using a haze meter.

The smectic liquid crystal phase represented by the polymerizable liquid crystal compound is more preferably a higher order smectic phase. The higher order smectic phases referred to herein are smectic b phase, smectic d phase, smectic e phase, smectic f phase, smectic g phase, smectic h phase, smectic i phase, smectic j phase, smectic The K phase and the Smectic L phase, among them, the Smectic B phase, the Smectic F phase, and the Smectic I phase are more preferable. When the smectic liquid crystal phase represented by the polymerizable liquid crystal compound is these higher order smectic phases, the present polarizing film with higher alignment order can be produced. In addition, this polarizing film having a high degree of orientation can obtain a black peak derived from a higher order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement.

As the polymerizable liquid crystal compound, a compound having a temperature of 40 ° C to 200 ° C is preferably a phase transition from a nematic liquid crystal phase to a smectic liquid crystal phase, and more preferably a compound having a temperature of 60 ° C to 140 ° C.

Preferred polymerizable liquid crystal compounds include, for example, compounds represented by formula (1) (hereinafter referred to as "compound (1)" in some cases).

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (1)

[In the formula (1),

X ¹ , X ² and X ³ each independently represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, at least 1 of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent. -CH ₂ -constituting the cyclohexane-1,4-diyl group may be substituted with -O-, -S- or -NR-. R represents a C1-C6 alkyl group or a phenyl group.

Y ¹ and Y ² are independently of each other -CH ₂ CH _2- , -CH ₂ O-, -COO-, -OCOO-, single bond, -N = N-, -CR ^a = CR ^b- , -C≡ C- or -CR ^a = N-. R ^a and R ^b independently of each other represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

U ¹ represents a hydrogen atom or a polymerizable group.

U ² represents a polymerizable group.

W ¹ and W ² independently of each other represent a single bond, -O-, -S-, -COO- or -OCOO-.

V ¹ and V ² each independently represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ -constituting the alkanediyl group is substituted with -O-, -S- or -NH- It may be.]

In compound (1), it is preferable that two or more of X ¹ , X ² and X ³ are 1,4-phenylene groups which may have a substituent.

It is preferable that the 1,4-phenylene group which may have a substituent is unsubstituted. The cyclohexanoic acid-1,4-diyl group which may have a substituent is preferably a trans-cyclohexanoic acid-1,4-diyl group which may have a substituent, and the trans-cyclohexanoic acid-1 which may have a substituent. It is preferable that the, 4-diyl group is unsubstituted.

Substituents optionally having a 1,4-phenylene group which may have a substituent or a cyclohexanoic acid-1,4-diyl group which may have a substituent include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group and butyl group; Cyano group; And halogen atoms.

Y ¹ of the compound (1) is preferably -CH ₂ CH _2- , -COO- or a single bond, and Y ² is preferably -CH ₂ CH ₂ -or -CH ₂ O-.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, and preferably a polymerizable group. U ¹ and U ² are both preferably a polymerizable group, and preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that receives energy by light and is involved in polymerization. The polymerizable liquid crystal compound having a photopolymerizable group is also advantageous in that it can polymerize under lower temperature conditions. As the photopolymerizable group, a radically polymerizable group is preferable. The radical polymerizable group means a group capable of participating in the polymerization reaction by an active radical generated from a polymerization initiator described later.

In compound (1), the polymerizable groups of U ¹ and U ² may be different from each other, but the same is preferable. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group and oxetanyl group. Especially, acryloyloxy group, methacryloyloxy group and vinyloxy group are preferable, and acryloyloxy group and methacryloyloxy group are more preferable.

The alkanediyl groups of V ¹ and V ² include methylene group, ethylene group, propane-1,3-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, and pentane-1,5- Diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decan-1,10-diyl group, tetradecane-1,14-diyl group and echo And acid-1,20-diyl group. V ¹ and V ² are preferably an alkanediyl group having ² to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

Although a cyano group and a halogen atom etc. are mentioned as a substituent optionally having an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, the alkanediyl group is preferably unsubstituted, and unsubstituted and straight-chain alkanediyl group. It is more preferable.

W ¹ and W ² are each independently a single bond or -O-.

Specific examples of the compound (1) include compounds represented by formulas (1-1) to (1-23). When the specific example of such compound (1) has a cyclohexane-1,4-diyl group, it is preferable that the cyclohexane-1,4-diyl group is a transchain.

The polymerizable liquid crystal compound can be used alone or in combination of two or more. When mixing 2 or more types, it is preferable that 1 or more types are compound (1), and 2 or more types are more preferable if they are compound (1). The mixing ratio when two types of polymerizable liquid crystal compounds are mixed is usually 1:99 to 50:50, preferably 5:95 to 50:50, and more preferably 10:90 to 50:50.

The polymerization temperature of this composition is usually below the smectic phase transition temperature of the polymerizable liquid crystal compound. The polymerization temperature of the composition can be controlled by adjusting the components included in the composition. It is preferable to obtain the smectic phase transition temperature of the polymerizable liquid crystal compound in advance and adjust components other than the polymerizable liquid crystal compound so that the present composition is polymerized under temperature conditions below the phase transition temperature. When 2 or more types of polymerizable liquid crystal compounds are contained in this composition, the smectic phase transition temperature of the mixture of the 2 or more types of polymerizable liquid crystal compounds is determined and controlled in the same manner.

Among the exemplified compounds (1), formula (1-2), formula (1-3), formula (1-4), formula (1-6), formula (1-7), formula (1-8), Compounds represented by the formulas (1-13), (1-14) and (1-15) are preferred. These compounds can be easily polymerized under interaction with other polymerizable liquid crystal compounds or polymerizable non-liquid crystal compounds under temperature conditions below the smectic phase transition temperature, i.e., while maintaining the liquid state of the higher order smectic phase sufficiently. have.

The content ratio of the polymerizable liquid crystal compound in the present composition is usually 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, and more preferably 80 to 94 parts by mass, relative to 100 parts by mass of the solid content of the present composition. Parts, and more preferably 80 to 90 parts by mass. When the content ratio of the compound (1) is within the above range, the orientation of the compound (2) described later tends to increase, which is preferable. Here, solid content means the total amount of components excluding the solvent in this composition.

The polymerizable liquid crystal compound is, for example, Lub et al. Recl. Trav. Chim. It is produced by a known method as described in Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156.

<Polymerizable non-liquid crystal compound>

The polymerizable non-liquid crystal compound of the present invention means a compound that has a polymerizable group and does not have a liquid crystal state between a solid and a liquid even with a change in temperature.

The polymerizable non-liquid crystal compound has (i) no coloring in itself (absorption to visible light), (ii) compatibility with a degree of uniform mixing with the polymerizable liquid crystal compound, and (iii) polymerizable liquid crystal. It is suitable if the formation of the liquid crystal state represented by the compound is not inhibited.

Monofunctional acrylates and polyfunctional acrylates are mentioned as the polymerizable non-liquid crystal compound. Monofunctional means having one polymerizable group, polyfunctional means having a plurality of polymerizable groups. A polyfunctional acrylate is preferable in that the polymerization reaction between the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound proceeds continuously. The number of polymerizable groups of the polymerizable non-liquid crystal compound is preferably 1 to 6, more preferably 2 to 6.

It is suitable if the polymerizable group of the polymerizable non-liquid crystal compound is the same as the polymerizable group of the polymerizable liquid crystal compound.

Moreover, when one or more compounds selected from a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound have a plurality of polymerizable groups, one or more polymerizable groups of the polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound have It is suitable that at least one polymerizable group is the same.

More suitable polymerizable non-liquid crystal compounds have the characteristics of (i), (ii) and (iii) above, and monofunctional acrylates having 1 to 6, preferably 2 to 6 polymerizable groups in the molecule. And polyfunctional acrylates. In addition, since these monofunctional acrylates and polyfunctional acrylates are non-liquid crystalline, it is preferable not to have a mesogen structure. In addition, the urethane structure, amino structure, epoxy structure, ethylene glycol structure and polyester structure in the molecule within a range that does not disturb the nematic liquid crystal phase and the smectic liquid crystal phase of the polymerizable liquid crystal compound contained in the coating film obtained from the present composition. It may contain.

The polymerizable non-liquid crystal compound can be used alone or in combination of two or more in the present composition.

The monofunctional acrylate is a group selected from the group consisting of acryloyloxy group (CH ₂ = CH-COO-) and methacryloyloxy group (CH ₂ = C (CH ₃ ) -COO-) [hereafter, (meth ) May be described as an acryloyloxy group]. When the polymerizable non-liquid crystal compound is a monofunctional acrylate, it is preferable that the polymerizable liquid crystal compound also has a (meth) acryloyloxy group.

Monofunctional acrylates having one (meth) acryloyloxy group include alkyl (meth) acrylates having 4 to 16 carbon atoms, β carboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylated phenyls having 2 to 14 carbon atoms. (Meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, and isobornyl (meth) acrylate.

The polyfunctional acrylate is usually a compound having 2 to 6 (meth) acryloyloxy groups in the molecule. When the polymerizable non-liquid crystal compound is a polyfunctional acrylate, it is preferable that the polymerizable liquid crystal compound also has a (meth) acryloyloxy group.

Examples of the bifunctional acrylate having two (meth) acryloyloxy groups include 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate; Ethylene glycol di (meth) acrylate; Diethylene glycol di (meth) acrylate; Neopentyl glycol di (meth) acrylate; Triethylene glycol di (meth) acrylate; Tetraethylene glycol di (meth) acrylate; Polyethylene glycol diacrylate; Bis (acryloyloxyethyl) ether of bisphenol A; Ethoxylated bisphenol A di (meth) acrylate; Propoxylated neopentyl glycol di (meth) acrylate; And ethoxylated neopentyl glycol di (meth) acrylate and 3-methylpentanediol di (meth) acrylate.

Polyfunctional acrylates having 3 to 6 (meth) acryloyloxy groups include trimethylolpropane tri (meth) acrylate; Pentaerythritol tri (meth) acrylate; Tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; Ethoxylated trimethylolpropane tri (meth) acrylate; Propoxylated trimethylolpropane tri (meth) acrylate; Pentaerythritol tetra (meth) acrylate; Dipentaerythritol penta (meth) acrylate; Dipentaerythritol hexa (meth) acrylate; Tripentaerythritol tetra (meth) acrylate; Tripentaerythritol penta (meth) acrylate; Tripentaerythritol hexa (meth) acrylate; Tripentaerythritol hepta (meth) acrylate; Tripentaerythritol octa (meth) acrylate;

Reactant of pentaerythritol tri (meth) acrylate and acid anhydride; A reactant of dipentaerythritol penta (meth) acrylate with an acid anhydride;

Reactant of tripentaerythritol hepta (meth) acrylate with acid anhydride;

Caprolactone modified trimethylolpropane tri (meth) acrylate; Caprolactone modified pentaerythritol tri (meth) acrylate; Caprolactone modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; Caprolactone modified pentaerythritol tetra (meth) acrylate; Caprolactone-modified dipentaerythritol penta (meth) acrylate; Caprolactone modified dipentaerythritol hexa (meth) acrylate; Caprolactone-modified tripentaerythritol tetra (meth) acrylate; Caprolactone modified tripentaerythritol penta (meth) acrylate; Caprolactone modified tripentaerythritol hexa (meth) acrylate; Caprolactone-modified tripentaerythritolhepta (meth) acrylate; Caprolactone-modified tripentaerythritol octa (meth) acrylate; Reactant of caprolactone-modified pentaerythritol tri (meth) acrylate with acid anhydride; And reaction products of caprolactone-modified dipentaerythritol penta (meth) acrylate and acid anhydrides, and caprolactone-modified tripentaerythritol hepta (meth) acrylate and acid anhydrides. In addition, in the specific example of the polyfunctional acrylate shown here, (meth) acrylate means acrylate or methacrylate. In addition, the caprolactone modification means that the ring-opening or ring-opening polymer of caprolactone is introduced between the alcohol-derived portion of the (meth) acrylate compound and the (meth) acryloyloxy group.

A commercial item can also be used for such a polyfunctional acrylate.

As such commercial products, A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, A-GLY-9E, A-GLY-20E, A-TMM -3, A-TMPT, AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH, HD-N, NOD-N, NPG, TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.), " ARONIX M-220 "," ARONIX M-325 "," ARONIX M-240 "," ARONIX M-270 "," ARONIX M-309 "," ARONIX M-310 "," ARONIX M-321 "," ARONIX M-350 "," ARONIX M-360 "," ARONIX M-305 "," ARONIX M-306 "," ARONIX M-450 "," ARONIX M-451 "," ARONIX M-408 "," ARONIX M -400 "," ARONIX M-402 "," ARONIX M-403 "," ARONIX M-404 "," ARONIX M-405 "," ARONIX M-406 "(manufactured by Toagosei Corporation)," EBECRYL11 " , "EBECRYL145", "EBECRYL150", "EBECRYL40", "EBECRYL140", "EBECRYL180", DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA, TMPTA, TMPEOTA, DPHA, EBECRYL series Manufacturing) and the like.

Preferred polyfunctional acrylates include compounds represented by the following formulas (4-1) to (4-14), respectively.

The content of the polymerizable non-liquid crystal compound in the present composition is usually 0.1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 3 to 7% by mass, based on the total mass of the present composition. to be. More preferably, it is 0.1 to 19 parts by mass, more preferably 1 to 15 parts by mass, and particularly preferably 4 to 10 parts by mass with respect to 100 parts by mass of solid content of the present composition. Moreover, it is especially preferable if it is 3 mass parts or more and 10 mass parts or less with respect to 100 weight part of polymerizable liquid crystal compounds. When the content of the polymerizable non-liquid crystal compound is within the above range, the polymerizable components (polymerizable liquid crystal compound and polymerizable non-liquid crystal compound) in the composition are not disturbed without disturbing the alignment of the polymerizable liquid crystal compound contained in the coating film obtained from the composition. ) Because it can be copolymerized. Although it differs depending on the type of each of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound, when the content of the polymerizable non-liquid crystal compound is more than the above range, the transparency of the polarizing film tends to decrease, which is not preferable.

<Dichroic pigment>

The dichroic dye refers to a dye having a property that the absorbance in the long axis direction of the molecule and the absorbance in the minor axis direction are different. As long as it has such properties, the dichroic dye may be a dye or a pigment, or a mixture of multiple types of compounds.

It is preferable that the dichroic dye has a maximum absorption wavelength (λMAX) in a range of 300 to 700 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, and azo dyes are particularly preferred. Examples of the azo pigment include mono azo pigments, bis azo pigments, tris azo pigments, tetrakis azo pigments, stilbene azo pigments, and the like, preferably bis azo pigments and tris azo pigments.

Examples of the azo dye include a compound represented by the formula (2) (hereinafter referred to as “compound (2)” in some cases).

A ¹ (-N = NA ² ) _p -N = NA ³ (2)

[In the formula (2),

A ¹ and A ³ each independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. A ² represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents the integer of 1-4. When p is an integer of 2 or more, a plurality of A ² may be the same as or different from each other.]

Examples of the monovalent heterocyclic group include a group obtained by subtracting one hydrogen atom from heterocyclic compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzoimidazole, oxazole and benzoxazole. A group obtained by subtracting two hydrogen atoms from a heterocyclic compound corresponds to a divalent heterocyclic group, and specific examples of the heterocyclic compound are as described above.

A phenyl group, a naphthyl group and a monovalent heterocyclic group in A ¹ and A ³ , and a p-phenylene group, a naphthalene-1,4-diyl group in A ² and a divalent heterocyclic group optionally have carbon atoms 1-4 alkyl groups; Alkoxy groups having 1 to 4 carbon atoms such as methoxy group, ethoxy group and butoxy group; Alkyl groups having 1 to 4 carbon atoms, such as trifluoromethyl group; Cyano group; Nitro group; Halogen atom; Substituted or unsubstituted amino groups such as amino groups, diethylamino groups and pyrrolidino groups (Substituted amino groups are amino groups having one or two alkyl groups having 1 to 6 carbon atoms, or 2 substituted alkyl groups having 2 to 8 carbon atoms bonded to each other) Means an amino group forming an alkanediyl group of unsubstituted amino groups is -NH _2. ). In addition, the specific example of a C1-C6 alkyl group is the same as what was illustrated by the substituent which the phenylene group etc. of compound (1) have arbitrarily.

Among the compounds (2), compounds represented by the following formulas (2-1) to (2-6) are preferable.

[In the formulas (2-1) to (2-6),

B ^{1 to} B ²⁰ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, or a substituted or unsubstituted amino group (substituted amino group and unsubstituted amino group are defined above) One), a chlorine atom or a trifluoromethyl group.

n1-n4 represent the integer of 0-3 independently of each other.

When n1 is 2 or more, a plurality of B ² may be the same as or different from each other,

When n2 is 2 or more, a plurality of B ^{6 s} may be the same as or different from each other,

When n3 is 2 or more, a plurality of B ⁹ may be the same or different from each other,

When n4 is 2 or more, a plurality of B ¹⁴ may be the same as or different from each other.]

The anthraquinone dye is preferably a compound represented by formula (2-7).

[In the formula (2-7),

R ¹ to R ⁸ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

The oxazone dye is preferably a compound represented by formula (2-8).

[In the formula (2-8),

R ⁹ to R ¹⁵ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

The acridine dye is preferably a compound represented by the formula (2-9).

[In the formula (2-9),

R ¹⁶ to R ²³ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms.]

In the formulas (2-7), (2-8) and (2-9), the alkyl group having 1 to 4 carbon atoms represented by R ^x is a methyl group, ethyl group, propyl group, butyl group, pentyl group, and Hexyl group etc. are mentioned, As a C6-C12 aryl group, a phenyl group, a toluyl group, a xylyl group, and a naphthyl group etc. are mentioned.

The cyanine dye is preferably a compound represented by formula (2-10) and a compound represented by formula (2-11).

[In the formula (2-10),

D ¹ and D ² independently represent a group represented by any one of formulas (2-10a) to (2-10d).

n5 represents the integer of 1-3.]

[In the formula (2-11),

D ³ and D ⁴ independently represent a group represented by any one of formulas (2-11a) to (2-11h).

n6 represents the integer of 1-3.]

The content of the dichroic dye in the composition is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass with respect to 100 parts by mass of the content of the polymerizable liquid crystal compound. It is more preferably 10 parts by mass or more, and particularly preferably 0.1 parts by mass or more and 5 parts by mass or less. When the content of the dichroic dye is within this range, the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the present composition. Do. If the content of the dichroic dye is too large, there is a fear that the orientation of the polymerizable liquid crystal compound is inhibited. Therefore, the content of the dichroic dye can be determined within a range in which the polymerizable liquid crystal compound can maintain a liquid crystal state.

As the dichroic dye, commercially available ones can be used.

<Polymerization initiator>

The composition contains a polymerization initiator. The polymerization initiator is a compound capable of initiating a polymerization reaction such as a polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator capable of generating active radicals by the action of light is preferable.

Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkylphenone compounds, acylphosphine oxide compounds, triazine compounds, iodonium salts and sulfonium salts.

Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, 3,3 ', 4,4'-tetra (tert-butylper Oxycarbonyl) benzophenone and 2,4,6-trimethylbenzophenone.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, and 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2- Hydroxy-2-methyl-1- [4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexylphenylketone and 2-hydroxy-2-methyl-1- [4 And oligomers of-(1-methylvinyl) phenyl] propan-1-one.

Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide.

Triazine compounds include, for example, 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- ( 4-methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2, 4-bis (trichloromethyl) -6- [2- (5-methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) Ethenyl] -1,3,5-triazine and 2,4-bis (trichloromethyl) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine And the like.

As a polymerization initiator, what is marketed can be used. Commercially available polymerization initiators include "Irgacure 907", "Ilgacure 184", "Ilgacure 651", "Ilgacure 819", "Ilgacure 250", and "Ilgacure 369" [Chiba Japan ( week)]; "Sakeall BZ", "Sakeall Z", "Sakeall BEE" [Seiko Kagaku Co., Ltd.]; "Kayacure BP100" [Nihon Kayaku Co., Ltd.]; "Kayacure UVI-6992" (manufactured by Dow Corporation); "Adeca optomer SP-152", "adeca optomer SP-170" [ADEKA Corporation]; "TAZ-A", "TAZ-PP" (Nippen Siebel Hagner); And "TAZ-104" (Sanwa Chemical Co., Ltd.).

The content of the polymerization initiator in the composition can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. It is preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass. If the content of the polymerization initiator is within this range, it is preferable because the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be copolymerized without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the present composition.

<Solvent>

The composition contains a solvent. As the solvent, a solvent capable of completely dissolving a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, and a dichroic dye is preferable. Moreover, it is preferable that it is a solvent inert to the polymerization reaction in this composition.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate and ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as toluene and xylene, nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; And chlorine-containing solvents such as chloroform and chlorobenzene. These solvents may be used alone or in combination of a plurality.

The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the composition. In other words, 2-50 mass% of solid content in this composition is preferable. When the solid content is 2% by mass or more, the present polarizing film tends to be easily obtained and is preferable. Moreover, when the said solid content is 50 mass% or less, since the viscosity of this composition becomes low, since the thickness of this polarizing film becomes almost uniform, there exists a tendency for nonuniformity to occur in this polarizing film easily, and it is preferable. In addition, such a solid content can be determined in consideration of the thickness of the present polarizing film to be manufactured.

This composition may contain components other than the above-mentioned components, and examples of such components include polymerization reaction aids that control polymerization reactions such as polymerizable liquid crystal compounds.

<Preparation of polymerization reaction>

The composition may further contain a sensitizer. As a sensitizer, a photosensitizer is preferable. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (eg, 2,4-diethylthioxanthone, 2-isopropylthioxanthone); Anthracene compounds such as anthracene and alkoxy group-containing anthracene (eg, dibutoxyanthracene); Phenothiazine and rubrene; and the like.

When the composition contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound contained in the composition can be further promoted. The amount of the sensitizer is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 0.5 to 8 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound.

In order to stably advance the polymerization reaction, the composition may also contain a polymerization inhibitor appropriately. By containing a polymerization inhibitor, the progress of the polymerization reaction of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be controlled.

Examples of the polymerization inhibitor include hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butyl catechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, and the like. Radical supplements; Thiophenols; and β-naphthylamines and β-naphthols.

When this composition contains a polymerization inhibitor, the content of the polymerization inhibitor relative to 100 parts by mass of the polymerizable liquid crystal compound is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and 0.5 to 8 parts by mass is more preferable. If the content of the polymerization inhibitor is within this range, the orientation of the polymerizable liquid crystal compound contained in the composition for forming a polarizing film can be polymerized without disturbing, so that the polymerizable liquid crystal compound further satisfies the liquid crystal state. Polymerization can be carried out.

<Leveling agent>

It is preferable that this composition contains a leveling agent. The leveling agent has a function of adjusting the fluidity of the present composition and making the coating film obtained by applying the present composition more flat, and a surfactant and the like. The leveling agent is more preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component. In addition, the polyacrylate compound mentioned here does not have a polymerizable group.

Leveling agents based on polyacrylate compounds include "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-358N" and "BYK- 361N "," BYK-380 "," BYK-381 "and" BYK-392 "(BYK Chemie).

Leveling agents based on fluorine atom-containing compounds include "Megapack R-08", "Megapack R-30", "Megapack R-90", "Megapack F-410", "Megapack F-411" , "Megapack F-443", "Megapack F-445", "Megapack F-470", "Megapack F-471", "Megapack F-477", "Megapack F-479", " Megapack F-482 "and" Megapack F-483 "[DIC Corporation]; "Surfron S-381", "Surfron S-382", "Surfron S-383", "Surfron S-393", "Surfron SC-101", "Surfron SC-105", "KH -40 "and" SA-100 "[AGC Sei Chemical Co., Ltd.]; "E1830", "E5844" (Daikin Fine Chemical Genkyusho); "Ftop EF301", "Ftop EF303", "Ftop EF351" and "Ftop EF352" (Mitsubishi Materials Denshi Kasei Co., Ltd.) and the like.

When a leveling agent is contained in this composition, the content is preferably 0.3 parts by mass or more and 5 parts by mass or less, more preferably 0.5 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above-mentioned range, it is easy to align the polymerizable liquid crystal compound horizontally, and it is preferable because the resulting polarizing film tends to be smoother. When the content of the leveling agent in the polymerizable liquid crystal compound exceeds the above-mentioned range, unevenness tends to occur in the resulting polarizing film, which is not preferable. Moreover, this composition may contain 2 or more types of leveling agents.

<Method of forming this polarizing film>

Next, a method of forming the present polarizing film with the composition will be described. First, the composition is applied on a substrate or on an alignment film formed on the substrate. Preferably, it is applied on an alignment film formed on a substrate. A transparent substrate is preferred as the substrate.

<Transparent description>

A transparent substrate is a substrate having a transparency sufficient to transmit light, particularly visible light. The transparency refers to a property in which transmittance to light rays over a wavelength of 380 to 780 nm is 80% or more. Specifically, if such a transparent substrate is exemplified, a glass substrate or a plastic substrate can be cited. Further, plastics constituting the plastic substrate include, for example, polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; Cyclic olefin resins; Polyvinyl alcohol; Polyethylene terephthalate; Polymethacrylic acid esters; Polyacrylic acid esters; Cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; Polyethylene naphthalate; Polycarbonate; Polysulfone; Polyethersulfone; Polyether ketone; And plastics such as polyphenylene sulfide and polyphenylene oxide. Among them, cellulose ester, cyclic olefin resin, polycarbonate, polyethylene terephthalate or polymethacrylic acid ester are particularly preferred because they are readily available on the market or have excellent transparency. In manufacturing the present polarizing film using such a transparent substrate, a support substrate or the like is adhered to the transparent substrate in that it can be easily handled without causing damage such as tearing when transporting or storing the transparent substrate. You may let it. Moreover, although it mentions later, when manufacturing an original polarizing plate from this polarizing film, there may be a case where a retardation property is provided to a plastic base material. In this case, the retardation property may be given to the plastic substrate by stretching treatment or the like. In addition, the method of imparting phase difference property to a transparent base material is demonstrated later.

In the cellulose ester, at least a part of hydroxyl groups contained in cellulose is acetic acid esterified. The cellulose ester film made of such a cellulose ester can be easily obtained in the market. Examples of commercially available triacetylcellulose films include "Fuji Tak Film" (Fuji Shashin Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Opt.). Such a commercially available triacetylcellulose film can be used as a transparent base material as it is or after providing retardation properties as necessary. Moreover, after performing surface treatment, such as anti-glare treatment, heart-coat treatment, antistatic treatment, or anti-reflection treatment, to the surface of the prepared transparent base material, it can be used as a transparent base material.

The cyclic olefin-based resin is composed of, for example, a polymer or copolymer (cyclic olefin-based resin) of a cyclic olefin such as norbornene or polycyclic norbornene-based monomer, and the cyclic olefin-based resin may partially include a ring-opening part. . Moreover, hydrogenated cyclic olefin resin containing a ring-opening part may be sufficient. Further, the cyclic olefin-based resin may be a copolymer of, for example, a cyclic olefin, a chain olefin, or a vinylated aromatic compound (styrene or the like) from the viewpoint of not significantly impairing transparency or significantly increasing hygroscopicity. Further, the cyclic olefin-based resin may have a polar group introduced into the molecule.

When the cyclic olefin resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the chain olefin is ethylene or propylene, and vinyl aromatic compounds include styrene, α-methylstyrene and alkyl. And substituted styrene. In such a copolymer, the content ratio of the structural unit derived from the cyclic olefin is in the range of 50 mol% or less, for example, about 15 to 50 mol%, based on the total structural unit of the cyclic olefin resin. When the cyclic olefin resin is a ternary copolymer obtained from a cyclic olefin, a chain olefin, and a vinylated aromatic compound, for example, the content ratio of the structural unit derived from the chain olefin is 5 to 5 based on the total structural unit of the cyclic olefin resin. It is about 80 mol%, and the content ratio of the structural unit derived from the vinylated aromatic compound is about 5 to 80 mol%. The cyclic olefin-based resin of such a terpolymer has an advantage in that the amount of the expensive cyclic olefin can be relatively reduced when producing the cyclic olefin-based resin.

The cyclic olefin resin can be easily obtained in the market. Commercially available cyclic olefin resins include "Topas" [Ticona (Germany)]; "Aton" [JSR Corporation]; "ZEONOR" and "ZEONEX" (Nihon Xeon Corporation); And "Apel" (manufactured by Mitsui Chemicals Co., Ltd.). Such a cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by, for example, forming a film by a known film forming means such as a solvent casting method or a melt extrusion method. Moreover, the cyclic olefin resin film already marketed in the form of a film can also be used. Examples of such commercially available cyclic olefin-based resin films include "ES Thinner" and "SCA40" (Sekisui Chemical Co., Ltd.); "Zenoah film" [Optis Corporation]; "Aton Film" (JSR Corporation) and the like.

Subsequently, a method of imparting retardation property to the plastic substrate will be briefly described. The plastic substrate can provide retardation properties by a known stretching method. For example, a roll (winding body) in which a plastic base material is wound on a roll is prepared, and the plastic base material is continuously unwound from such a winding body, and the unwound plastic base material is conveyed by a heating furnace. The set temperature of the heating furnace is in the range of the glass transition temperature (° C) to [glass transition temperature +100] (° C) of the plastic substrate, preferably near the glass transition temperature (° C) to [glass transition temperature +50]. It should be set to (° C). In the said heating furnace, when extending | stretching in the advancing direction of a plastic base material, or the direction orthogonal to a advancing direction, the conveying direction or tension is adjusted and inclined at an arbitrary angle, and a uniaxial or biaxial thermal stretching process is performed. The magnification of stretching is usually in the range of about 1.1 to 6 times, and preferably in the range of about 1.1 to 3.5 times. Moreover, as a method of extending | stretching in an oblique direction, if it can continuously incline an orientation axis to a desired angle, it will not specifically limit, A well-known stretching method can be employ | adopted. As such a stretching method, the method described in Unexamined-Japanese-Patent No. 50-83482 or Unexamined-Japanese-Patent No. 2-113920 is mentioned, for example.

The thickness of the transparent substrate is preferably thin in terms of weight and sufficient transparency to be able to handle practically. However, if it is too thin, the strength tends to decrease and workability tends to be poor. The suitable thickness of the glass substrate is, for example, about 100 to 3000 μm, and preferably 100 to 1000 μm. A suitable thickness of the plastic substrate is, for example, about 5 to 300 µm, and preferably 20 to 200 µm. When this polarizing film is used as a circular polarizing plate to be described later, a thickness of the transparent substrate is preferably thinner when used as a circular polarizing plate for mobile devices, and the thickness of the glass substrate is about 100 to 500 μm. Preferably, the thickness of the plastic substrate is preferably about 20 to 100 μm. Moreover, when giving a retardation property to a plastic base material by extending | stretching, the thickness after extending | stretching is determined according to the thickness before extending | stretching and a draw ratio.

<Orientation film>

It is preferable that an alignment film is formed in the base material used for manufacture of this polarizing film. In that case, the composition is applied on the alignment film. For this reason, it is preferable that the said alignment film has solvent tolerance to the extent that it does not melt | dissolve by application | coating of this composition. Moreover, it is preferable to have heat resistance in the heat processing for removal of a solvent and orientation of a liquid crystal. As such an alignment film, an alignment polymer can be used.

Examples of the oriented polymer include polyamide or gelatin having an amide bond in the molecule, polyimide having an imide bond in the molecule, and polyamic acid, a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, poly And polymers such as oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, or polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. These oriented polymers forming the alignment film may be used alone or in combination of two or more kinds.

The alignment polymer is an alignment polymer composition (a solution containing an alignment polymer) dissolved in a solvent, and can be formed on the substrate by coating on the substrate. Examples of the solvent include water; Alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone and methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; Aromatic hydrocarbon solvents such as toluene and xylene, nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran and dimethoxyethane; And chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene. These organic solvents may be used alone or in combination of multiple types.

In addition, a commercially available alignment film material may be used as it is as an alignment polymer composition for forming an alignment film. Examples of commercially available alignment film materials include "Sun Ever" (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) or "Optimer" (registered trademark, manufactured by JSR Corporation), and the like.

As a method for forming an alignment film on the substrate, for example, an alignment film can be formed on the substrate by applying the alignment polymer composition or a commercially available alignment film material onto the substrate, and then annealing. The thickness of the alignment film thus obtained is, for example, in the range of 10 nm to 10000 nm, and preferably in the range of 10 nm to 1000 nm.

In order to impart an orientation regulating force to the alignment film, it is preferable to perform rubbing as necessary (rubbing method). The polymerizable liquid crystal compound can be oriented in a desired direction by applying an alignment regulating force.

As a method of imparting an orientation regulating force by the rubbing method, for example, a rubbing roll in which a rubbing cloth is wound and rotated is prepared, and a laminate on which a coating film for forming an alignment film is formed on a substrate is placed on a stage and conveyed toward a rotating rubbing roll. And a method of bringing the coating film for forming an alignment film into contact with the rotating rubbing roll.

Further, a so-called photo-alignment film can also be used. With the photo-alignment film, a photo-alignment organic substance ( Iv) An alignment film formed by forming a layer and applying an alignment regulating force to the photo-alignment organic layer by irradiating polarized light (preferably polarized UV) to form a photo-alignment layer. The photoreactive group refers to a group that generates liquid crystal alignment ability by irradiating light (light irradiation). Specifically, it is to generate a photoreaction that is the origin of liquid crystal alignment ability, such as an alignment organic or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photolysis reaction of molecules generated by irradiating light. Among the photoreactive groups, it is preferable to cause a dimerization reaction or a photocrosslinking reaction in that it has excellent orientation and maintains a smectic liquid crystal state when a polarizing film is formed. As a photoreactive group capable of generating the above reaction, it is preferable to have an unsaturated bond, particularly a double bond, and a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), nitrogen Particularly preferred is a group having at least one selected from the group consisting of a nitrogen double bond (N = N bond) and a carbon-oxygen double bond (C = O bond).

Examples of the photoreactive group having a C = C bond include vinyl group, polyene group, stilbene group, stilazole group, stilbazolium group, calcon group, and cinnamoyl group. Examples of the photoreactive group having a C = N bond include a group having a structure such as an aromatic sheep base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, and a formazan group, and those having an azoxybenzene as a basic structure. Examples of the photoreactive group having a C = O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, and a cinnamoyl group and a chalcone group have a relatively small amount of polarization irradiation required for photoalignment, and it is easy to obtain a photoalignment layer excellent in thermal stability and temporal stability. Because it is preferred. More specifically, as the polymer having a photoreactive group, it is particularly preferable to have a cinnamoyl group in which the terminal end of the polymer side chain has a cinnamic acid structure.

As a solvent of the composition for forming a photo-alignment layer, it is preferable to dissolve a polymer and a monomer having a photoreactive group, and examples of the solvent include a solvent used in the above-mentioned oriented polymer composition.

The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming a photo-alignment layer can be appropriately adjusted according to the type of the polymer or monomer having this photoreactive group or the thickness of the photo-alignment film to be produced, but is expressed as a solid content concentration. It is preferable to be at least 0.2 mass%, and a range of 0.3 to 10 mass% is particularly preferable. In addition, in a range in which the properties of the photo-alignment film are not significantly impaired, the composition may contain a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer.

As a method of applying the composition for forming a photo-alignment layer on a substrate, coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator, or flexo printing A known method such as law is employed. In addition, when this polarizing film production is performed by the continuous manufacturing method of the roll-to-roll type mentioned later, the printing method, such as the gravure coating method, the die coating method, or the flexo method, is employ | adopted normally.

Moreover, when performing rubbing or polarization irradiation, if masking is performed, a plurality of regions (patterns) with different orientation directions may be formed.

<Method of manufacturing this polarizing film>

On the substrate or on the alignment film formed on the substrate, the present composition is applied to remove the solvent to obtain a coating film. As a method of coating (coating method), for example, the same method as exemplified as a method of applying a composition for forming an oriented polymer or a photo-alignment layer onto a substrate can be mentioned.

Next, the coating film is formed by removing the solvent under the condition that the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound contained in the coating film do not polymerize. Examples of the removal method include a natural drying method, a ventilation drying method, a heating drying method and a vacuum drying method. Subsequently, the polymerizable liquid crystal composition contained in this coating film is set to a state showing a smectic liquid crystal phase. In this case, it is preferable to make use of the properties of the polymerizable liquid crystal compound to make the liquid crystal state a nematic liquid crystal phase, and then transfer the nematic liquid crystal phase to a smectic liquid crystal phase. In order to transfer the liquid crystal phase in this way, first, the polymerizable liquid crystal compound contained in the coating film is heated to a temperature higher than or equal to the temperature representing the nematic liquid crystal phase, and subsequently cooled to a temperature at which the polymerizable liquid crystal compound represents the smectic liquid crystal phase. The method of making it is adopted is adopted.

As described above, the temperature at which the polymerizable liquid crystal compound in the coating film exhibits the smectic liquid crystal phase or the nematic liquid crystal phase may be determined in advance by texture observation using the present composition or the like.

When polymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound, in order for the polymerizable liquid crystal compound to maintain a smectic liquid crystal phase satisfactorily, the present composition comprising two or more polymerizable liquid crystal compounds as the polymerizable liquid crystal compound It is preferable to use. When the present composition in which the content ratio of the two or more types of polymerizable liquid crystal compounds is adjusted is used, after forming the smectic liquid crystal phase via the nematic liquid crystal phase, the supercooled state is temporarily formed even at the temperature representing the original crystal phase. It has the advantage that it is possible to easily maintain the liquid crystal state of the higher order smectic phase. The content ratio of the two types of polymerizable liquid crystal compounds when they contain two types of polymerizable liquid crystal compounds is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10 : 90 to 50:50.

Next, a polymerization step of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound will be described.

After making the polymerizable liquid crystal compound in the coating film into a smectic liquid crystal phase, the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound are polymerized by irradiating energy to the coating film while maintaining the smectic liquid crystal phase. Since this composition contains a polymerization initiator, it is preferable to irradiate the energy of the conditions in which the polymerization initiator is activated, and light is mentioned as a preferable energy. As the light to be irradiated, the type of polymerization initiator contained in the coating film or the type of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound (especially, the type of the polymerizer of the polymerizable liquid crystal compound) and the amount thereof may be appropriately applied. , Visible light, ultraviolet light, and laser light. Of these, ultraviolet light is preferred because it is easy to control the progress of the polymerization reaction, and that it can be used as a device for polymerization that is widely used in the field. Therefore, it is preferable to select the type of the polymerizable liquid crystal compound, the polymerizable non-liquid crystal compound, and the polymerization initiator contained in the composition so that polymerization can be performed by ultraviolet light. Moreover, when superposing | polymerizing, the polymerization temperature can also be controlled by cooling a coating film by an appropriate cooling means with ultraviolet light irradiation. If the polymerization of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be carried out at a lower temperature by the use of such a cooling means, even if the substrate described above uses a relatively low heat resistance, it is possible to properly form the polarizing film. There is also an advantage. Moreover, the patterned main polarizing film can also be obtained by performing masking or developing during polymerization.

By performing the polymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of the smectic phase, preferably the higher order smectic phase as already exemplified, to form the present polarizing film. This polarizing film obtained by polymerizing a polymerizable liquid crystal compound while maintaining a smectic liquid crystal state is polymerized while maintaining a conventional host guest type polarizing film, that is, a nematic liquid crystal state, depending on the action of the dichroic dye. There is an advantage that the polarization performance is high compared to a polarizing film obtained by polymerizing a liquid crystal compound or the like. In addition, there is an advantage that the strength is excellent compared to that applied only with a dichroic dye or a lyotropic liquid crystal.

The thickness of the polarizing film thus formed is preferably 0.5 µm or more and 10 µm or less, and more preferably 1 µm or more and 5 µm or less. Therefore, the thickness of the coating film for forming this polarizing film is determined in consideration of the thickness of the obtained polarizing film. In addition, the thickness of this polarizing film is calculated | required by the measurement of an interfering film thickness meter, a laser microscope, or a tactile film thickness meter.

Transparency can be evaluated by the haze value. The preferable haze value is 5% or less, and more preferably 2% or less.

The polarizing film thus formed is particularly preferable as long as a black peak is obtained in X-ray diffraction measurement as described above. As this main polarizing film from which such a black peak is obtained, the main polarizing film which shows a diffraction peak derived from a hexatic phase or a crystal phase is mentioned, for example.

<Continuous manufacturing method of this polarizing film>

In the above, although the outline of the manufacturing method of this polarizing film was demonstrated, when manufacturing this polarizing film commercially, the method which can manufacture this polarizing film continuously is calculated | required. Such a continuous manufacturing method is based on a roll-to-roll type, and in some cases, is referred to as a "main manufacturing method". In addition, in this manufacturing method, it demonstrates mainly in the case where a base material is a transparent base material.

The manufacturing method is, for example,

A step of preparing a first roll in which a transparent substrate is wound on a first winding core,

A step of continuously transmitting the transparent substrate from the first roll;

A step of continuously applying the composition for forming the photo-alignment layer to a transparent substrate,

A step of continuously removing a solvent from the applied composition for forming a photo-alignment layer and continuously forming a first coating film on the transparent substrate;

A step of continuously forming a photo-alignment layer by irradiating polarized UV to the coating film to form a photo-alignment film,

On the photo-alignment film, the step of continuously applying the present composition,

A step of continuously forming a second coating film on the photo-alignment film by drying the coated composition under conditions where the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound do not polymerize,

A step of continuously obtaining a polarizing film by making the liquid crystal state of the polymerizable liquid crystal compound contained in the coating film a smectic liquid crystal phase and then polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal phase,

The process of winding up the laminated body containing a transparent base material, a photo-alignment film, and a polarizing film to a 2nd winding core continuously, and obtaining a 2nd roll

Have Here, the manufacturing method will be described with reference to FIG. 1.

The first roll 210 in which the transparent substrate is wound on the first winding core 210A is readily available, for example, from the market. Among the transparent substrates already exemplified as a transparent substrate that can be obtained in the market in the form of such a roll, there may be mentioned films made of cellulose ester, cyclic olefin resin, polycarbonate, polyethylene terephthalate or polymethacrylic acid ester. . Moreover, when using this polarizing film as a circular polarizing plate, the transparent base material previously provided with retardation property can also be easily obtained in a market, For example, retardation film etc. which consist of cellulose ester, polycarbonate, or cyclic olefin resin. You can.

Subsequently, the transparent substrate is sent out from the first roll 210. The method of sending out the transparent substrate is performed by providing suitable rotating means on the winding core 210A of the first roll 210 and rotating the first roll 210 by the rotating means. In addition, an appropriate auxiliary roll 300 may be provided in the direction of discharging the transparent substrate from the first roll 210, and the transparent substrate may be sent out by means of rotation of the auxiliary roll 300. In addition, by providing the rotating means for both the first winding core 210A and the auxiliary roll 300, the transparent substrate may be delivered while providing appropriate tension to the transparent substrate.

When the transparent substrate sent out from the first roll 210 passes through the coating device 211A, a composition for forming a photo-alignment layer is coated on the surface by the coating device 211A. The coating device 211A for continuously applying the composition for forming the photo-alignment layer as described above is a printing device capable of applying a gravure coating method, a die coating method, or a flexo method.

The film passed through the coating device 211A is conveyed to a drying furnace 212A, heated by the drying furnace 212A, and a solvent is removed from the applied composition to continuously apply a first coating film on a transparent substrate. Form as As the drying furnace 212A, for example, a hot air-type drying furnace or the like is used. The set temperature of the drying furnace 212A is determined according to the kind of solvent contained in the composition for forming a photo-alignment layer applied by the coating device 211A. In addition, the drying furnace 212A may be divided into a plurality of zones, and may be a drying furnace having a different set temperature for each of the divided zones, a plurality of drying furnaces may be arranged in series, and a drying furnace for fluorspar having a different set temperature for each drying furnace. good.

The first coating film continuously formed by passing through the heating furnace 212A continues to be irradiated with polarized UV to the surface of the first coating film or the surface of the transparent substrate side by the polarizing UV irradiation device 213A to form a light alignment layer. To form a photo-alignment film.

The laminate of the substrate and the photo-alignment film continuously formed in this way is included in the composition by continuously passing the coating device 211B and then applying the composition on the photo-alignment film and then through the drying furnace 212B. The polymerizable liquid crystal compound becomes a second coating film showing a smectic liquid crystal phase. The drying furnace 212B has a role of removing a solvent from the composition applied on the photo-alignment film, and the polymerizable liquid crystal compound contained in the composition exhibits a smectic liquid crystal phase via a nematic liquid crystal phase. It plays a role of imparting heat energy to it. The drying furnace 212B may be capable of performing a multi-layer heat treatment in order to convert the polymerizable liquid crystal compound into a nematic liquid crystal phase and then to a smectic liquid crystal phase. That is, the drying furnace 212B may be divided into a plurality of zones, similar to the drying furnace 212A, and may be a drying furnace having a set temperature different for each of the divided zones. Each type may be a drying furnace having a different set temperature.

The film passed through the drying furnace 212B is sufficiently removed from the solvent contained in the composition, and is transported to the light irradiation device 213B while the polymerizable liquid crystal compound in the second coating film maintains the smectic liquid crystal phase. do. By light irradiation by the light irradiation device 213B, the polymerizable liquid crystal compound is photopolymerized with the polymerizable non-liquid crystal compound while maintaining the smectic liquid crystal phase, so that the polarizing film seen on the photo-alignment film is continuously formed.

The polarizing film thus formed continuously is wound on the second winding core 220A as a laminate including a transparent substrate and a photo-alignment film, and the shape of the second roll 220 is obtained. When the formed second polarizing film is wound to obtain a second roll, joint winding may be performed using a suitable spacer.

As described above, the transparent base material of the first roll / applying device 211A / drying furnace 212A / polarizing UV irradiation device 213A / applying device 211B / drying furnace 212B / lighting device 213B By passing in order, the polarizing film seen on the photo-alignment film on the transparent substrate is continuously produced.

In addition, in the present manufacturing method shown in FIG. 1, although a method of continuously manufacturing a transparent substrate to a polarizing film as seen has been shown, for example, a transparent substrate and a first roll / applying device 211A / drying furnace 212A / By passing in the order of the polarizing UV irradiation device (213A), a laminate of a substrate and a photo-alignment film continuously formed is wound on a winding core to prepare the laminate in the form of a roll, and the laminate is sent out from the roll, You may manufacture the polarizing film which passed the said laminated body sent out in the order of a coating apparatus 211B / drying furnace 212B / light irradiation apparatus 213B.

This polarizing film obtained by the present production method has a film shape and a long shape. When this polarizing film is used for a liquid crystal display device or the like described later, it is cut and used to have a desired dimension in accordance with a scale or the like of the liquid crystal display device.

The structure and manufacturing method of the present polarizing film have been mainly described in the case of the form of a laminate of the transparent substrate / light-aligning film / this polarizing film, but as the stacked body containing the polarizing film, a photo-alignment film or a transparent substrate from such a laminate May be peeled off, or may be in a form in which a layer or film other than the transparent substrate / light-alignment film / this polarizing film is laminated. As described above for these layers and films, the polarizing film may further include a retardation film, or may further include an antireflection layer or a brightness enhancing film.

Moreover, by making the transparent base material itself into a retardation film, it can also be set as the circular polarizing plate or elliptical polarizing plate in the form of a retardation film / light-alignment film / this polarizing film. For example, in the case of using a 1/4 wavelength plate uniaxially stretched as a retardation film, it is possible to produce an original polarizing plate with roll-to-roll by setting the irradiation direction of polarized UV to be approximately 45 ° with respect to the conveying direction of the transparent substrate. It is preferable that the in-plane retardation value with respect to visible light has a characteristic that becomes smaller as the wavelength becomes shorter as a quarter-wavelength plate used in manufacturing the original polarizing plate.

In addition, a 1 / 2-wave plate was used as the retardation film to produce a straight polarizing plate roll as set by shifting the angle between the slow axis and the absorption axis of the polarizing film, and the side opposite to the surface on which the polarizing film was formed. It is also possible to further form a quarter wave plate to form a circular circular polarizer.

<Use of this polarizing film>

This polarizing film can be used for various display devices. A display device is a device having a display element, and includes a light emitting element or a light emitting device as a light emitting source. As the display device, for example, a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (such as a field emission display device (FED), a surface field emission display device) (SED)], electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (such as a display device having a grating light valve (GLV), a digital micromirror device (DMD))) and And piezoelectric ceramic displays, etc. The liquid crystal display device includes any one of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection type liquid crystal display device. The display device may be a display device displaying a two-dimensional image, or a three-dimensional display device displaying a three-dimensional image.

In particular, the polarizing film can be effectively used for a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL) display device.

2 and 5 are schematic diagrams schematically showing a cross-sectional configuration of a liquid crystal display device (hereinafter referred to as "the present liquid crystal display device") 10 using the present polarizing film. The liquid crystal layer 17 is sandwiched between two substrates 14a and 14b.

Fig. 10 is a schematic diagram schematically showing a cross-sectional configuration of an EL display device (hereinafter referred to as "this EL display device" in some cases) using the present polarizing film.

11 is a schematic view schematically showing the configuration of a projection type liquid crystal display device using the polarizing film.

First, the present liquid crystal display device 10 shown in Fig. 2 will be described.

A color filter 15 is disposed on the liquid crystal layer 17 side of the base material 14a. The color filter 15 is disposed at a position facing the pixel electrode 22 with the liquid crystal layer 17 interposed therebetween, and the black matrix 20 is arranged at a position facing the boundary between the pixel electrodes. The transparent electrode 16 is disposed on the liquid crystal layer 17 side so as to cover the color filter 15 and the black matrix 20. Further, an overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16.

The thin film transistor 21 and the pixel electrode 22 are regularly arranged on the liquid crystal layer 17 side of the base material 14b. The pixel electrode 22 is disposed at a position facing the color filter 15 with the liquid crystal layer 17 interposed therebetween. An interlayer insulating film 18 having a connection hole (not shown) is disposed between the thin film transistor 21 and the pixel electrode 22.

Glass substrates and plastic substrates are used as the substrates 14a and 14b. As such a glass substrate or a plastic substrate, a transparent substrate used in the production of the polarizing film may be used as the one illustrated. Moreover, the transparent base material of this polarizing film may also serve as the base material 14a and the base material 14b. When manufacturing the color filter 15 or the thin film transistor 21 formed on the substrate, when a process of heating to a high temperature is required, a glass substrate or a quartz substrate is preferable.

As the thin film transistor, an optimum one can be used depending on the material of the base material 14b. Examples of the thin film transistor 21 include a high-temperature polysilicon transistor formed on a quartz substrate, a low-temperature polysilicon transistor formed on a glass substrate, and an amorphous silicon transistor formed on a glass substrate or plastic substrate. In order to further downsize this liquid crystal display device, a driver IC may be formed on the base material 14b.

A liquid crystal layer 17 is disposed between the transparent electrode 16 and the pixel electrode 22. The liquid crystal layer 17 is provided with a spacer 23 in order to maintain a constant distance between the substrate 14a and the substrate 14b. In addition, although it is shown in FIG. 2 as a columnar spacer, this spacer is not limited to the columnar column, and the shape is arbitrary as long as the distance between the substrate 14a and the substrate 14b can be kept constant.

Among the layers formed on the base material 14a and the base material 14b, alignment layers for aligning the liquid crystal in a desired direction may be disposed on the surfaces of the base layer 14 and the liquid crystal layer 17 that are in contact with each other. Moreover, this polarizing film can also be arrange | positioned inside a liquid crystal cell, ie, this polarizing film can be arrange | positioned on the surface side contacting the liquid crystal layer 17. This format is hereinafter referred to as "in-cell format".

Each member includes a base material 14a, a color filter 15 and a black matrix 20, a transparent electrode 16, a liquid crystal layer 17, a pixel electrode 22, an interlayer insulating film 18, and a thin film transistor 21 And the substrates 14b in order.

Among the substrates 14a and 14b with the liquid crystal layer 17 interposed therebetween, polarizers 12a and 12b are provided outside the substrates 14a and 14b, one of them The polarizing film seen in the above polarizer is included.

Moreover, it is preferable if retardation layers (for example, 1/4 wavelength plate or optical compensation film) 13a and 13b are laminated. Among the polarizers 12a and 12b, by disposing the polarizing film on the polarizer 12b, the function of converting incident light into linearly polarized light can be provided to the liquid crystal display device 10. Note that the retardation films 13a and 13b may not be disposed depending on the structure of the liquid crystal display device or the type of liquid crystal compound contained in the liquid crystal layer 17, and the transparent base material is a retardation film. In the case of using the included (other) circular polarizing plate, since the retardation film can be used as a retardation layer, the retardation layers 13a and / or 13b in FIG. 2 can also be omitted. A polarizing film may be further provided on the light emission side (outside) of the polarizer including the polarizing film.

In addition, an antireflection film for preventing reflection of external light may be disposed on the outside of the polarizer including the present polarizing film (when a polarizing film is further provided on the polarizing film).

As described above, the polarizing film can be used for the polarizer 12a or 12b of the liquid crystal display device 10 of FIG. 2. By providing this polarizing film on the polarizers 12a and / or 12b, there is an effect that further reduction in thickness of the liquid crystal display device 10 can be achieved.

When this polarizing film is used for the polarizer 12a or 12b, the lamination order is not specifically limited. This will be described with reference to partially enlarged views of A and B surrounded by dotted lines in FIG. 2.

3 is a partially enlarged schematic cross-sectional view of A of FIG. 2. In (A1) of FIG. 3, when the polarizer 100 is used as the polarizer 12a, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 viewed from the retardation layer 13a side are arranged in this order. It shows that it is installed as much as possible. In addition, (A2) of FIG. 3 shows that the transparent substrate 1, the photo-alignment film 2, and the polarizing film 3 are arranged in this order from the retardation layer 13a side.

4 is a partially enlarged schematic diagram of B in FIG. 2. 4 (B1), when the polarizer 100 is used as the polarizer 12b, the transparent substrate 1, the photo-alignment film 2, and the present polarizing film 3 are in this order from the retardation film 13b side. It is installed to be placed. 4 (B2), when the polarizer 100 is used as the polarizer 12b, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 viewed from the retardation film 13b side are in this order. It is installed to be placed.

A backlight unit 19 serving as a light emission source is disposed outside the polarizer 12b. The balllight unit 19 includes a light source, a light guide body, a reflector, a diffusion sheet, and a viewing angle adjustment sheet. Examples of light sources include electroluminescence, cold cathode tubes, hot cathode tubes, light emitting diodes (LEDs), laser light sources, and mercury lamps. In addition, the type of the polarizing film viewed according to the characteristics of the light source can be selected.

When the liquid crystal display device 10 is a transmissive liquid crystal display device, the white light generated from the light source in the backlight unit 19 enters the light guide body, and the course is changed by the reflector to diffuse through the diffusion sheet. The diffused light enters the polarizer 12b from the backlight unit 19 after being adjusted to have a desired directivity by the viewing angle adjustment sheet.

Among incident light which is unpolarized light, only one linearly polarized light passes through the polarizer 12b of the liquid crystal panel. The linearly polarized light is converted into circularly polarized light or elliptical polarized light by the retardation layer 13b, and sequentially passes through the substrate 14b, the pixel electrode 22, and the like to reach the liquid crystal layer 17.

Here, the alignment state of the liquid crystal molecules included in the liquid crystal layer 17 is changed according to the presence or absence of a potential difference between the pixel electrode 22 and the opposing transparent electrode 16, so that the luminance of light emitted from the liquid crystal display device 10 is changed. Controlled. When the liquid crystal layer 17 is in an alignment state that transmits polarized light as it is, the polarized light passes through the liquid crystal layer 17 and the transparent electrode 16, and light in a specific wavelength range passes through the color filter 15. The polarizer 12a is reached, and the liquid crystal display device brightly displays the color determined by the color filter.

Conversely, when the liquid crystal layer 17 is in an alignment state that converts and transmits polarized light, light transmitted through the liquid crystal layer 17, the transparent electrode 16, and the color filter 15 is absorbed by the polarizer 12a. . Thereby, this pixel displays black. In the intermediate alignment state between these two states, since the luminance of the light emitted from the liquid crystal display device 10 is also in the middle of both, the pixel displays an intermediate color.

When the present liquid crystal display device 10 is a semi-transmissive liquid crystal display device, it is preferable to use one in which a quarter wave plate is further laminated (circular polarizing plate) on the polarizing layer side of the present polarizing film. At this time, the pixel electrode 22 has a transmission portion formed of a transparent material and a reflection portion formed of a material that reflects light, and in the transmission portion, an image is displayed in the same manner as the transmission liquid crystal display device described above. On the other hand, in the reflection unit, external light is incident on the liquid crystal display, and the circularly polarized light transmitted through the polarizing film through the action of the quarter wave plate further provided in the polarizing film passes through the liquid crystal layer 17, and the pixel electrode It is reflected by (22) and used for display.

Next, this EL display device 30 using this polarizing film will be described with reference to FIG. 8. When using this polarizing film for this EL display device, it is preferable to use this polarizing film after setting it as a circularly polarizing plate (hereinafter referred to as "the original polarizing plate" in some cases). There are usually two embodiments of the original polarizing plate. So, before explaining the configuration and the like of the EL display device 30, two embodiments of the original polarizing plate will be described with reference to FIG.

6A is a cross-sectional view schematically showing a first embodiment of the original polarizing plate 110. This first embodiment is the original polarizing plate 110 in which a retardation layer (phase difference film) 4 is further provided on the polarizing film 3 in the polarizer 100. 6B is a cross-sectional view schematically showing a second embodiment of the original polarizing plate 110. In the second embodiment, the transparent substrate 1 used when manufacturing the polarizer 100 is a transparent substrate [1; By using the retardation film 4], it is the original polarizing plate 110 in which the transparent base material 10 itself has a function as the retardation layer 4.

Here, the manufacturing method of the original polarizing plate 110 will be described. As already described in the second embodiment of the original polarizing plate 110, in the present manufacturing method for manufacturing the present polarizing film 100, the transparent substrate 1, which is previously provided with a retardation property as the transparent substrate 1, that is, It can manufacture by using a retardation film. In the first embodiment of the original polarizing plate 110, the retardation layer 4 may be formed by bonding a retardation film onto the polarizing film 3 produced by the production method B. In addition, when the present polarizing film 100 is manufactured in the form of the second roll 220 by the present manufacturing method B, the polarizing film 100 seen from the second roll 220 is unwound and predetermined. After cutting to the dimensions, the form of bonding the retardation film to the cut polarizing film 100 may be good, but by preparing a third roll in which the retardation film is wound on a winding core, the shape is a film-shaped and long-form original. The polarizing plate 110 may be continuously manufactured.

A method of continuously manufacturing the first embodiment of the original polarizing plate 110 will be described with reference to FIG. 7. This manufacturing method,

A step of unwinding the polarizing film 100 continuously viewed from the second roll 220, and continuously unwinding the retardation film from the third roll 230 on which the retardation film is wound;

A process of forming the original polarizing plate 110 by continuously bonding the polarizing layer installed on the polarizing film 100 unwound from the second roll 220 and the retardation film unwound from the third roll,

The formed original polarizing plate 110 is wound up on a fourth winding core 240A, and is made of a process of obtaining a fourth roll 240.

As described above, the manufacturing method of the first embodiment of the original polarizing plate 110 has been described, but when bonding the polarizing film 3 in the polarizer 100 and the retardation film, a suitable adhesive is used, and the adhesive is formed. The polarizing film 3 seen through the adhesive layer and the retardation film may be bonded.

Next, this EL display device provided with the original polarizing plate 110 will be described with reference to FIG. 8.

In this EL display device 30, an organic functional layer 36 and a cathode electrode 37, which are light emitting sources, are stacked on a substrate 33 on which a pixel electrode 35 is formed. A circular polarizing plate 31 is disposed on the opposite side to the organic functional layer 36 with the substrate 33 interposed therebetween, and the original polarizing plate 110 is used as the circular polarizing plate 31. The organic functional layer 36 emits light by applying a positive voltage to the pixel electrode 35 and a negative voltage to the cathode electrode 37 and applying a direct current between the pixel electrode 35 and the cathode electrode 37. . The organic functional layer 36, which is a light emission source, is composed of an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the substrate 33, and the original polarizing plate 31 (this original polarizing plate 110). Although an organic EL display device having an organic functional layer 36 is described, it may be applied to an inorganic EL display device having an inorganic functional layer.

In order to manufacture the EL display device 30, first, the thin film transistor 40 is formed on the substrate 33 in a desired shape. Then, the interlayer insulating film 34 is formed, and then the pixel electrode 35 is formed by sputtering to pattern it. Thereafter, the organic functional layer 36 is laminated.

Subsequently, the original polarizing plate 31 (this original polarizing plate 110) is provided on the opposite side of the surface on which the thin film transistor 40 of the substrate 33 is provided.

When the original polarizing plate 110 is used as the original polarizing plate 31, the lamination order will be described with reference to a partially enlarged view of C surrounded by the dotted line in FIG. When the original polarizing plate 110 is used as the original polarizing plate 31, the retardation layer 4 in the original polarizing plate 110 is disposed on the substrate 33 side. 9 (C1) is an enlarged view using the first embodiment of the original polarizing plate 110 as the original polarizing plate 31, and FIG. 9 (C2) shows the second embodiment of the original polarizing plate 110 It is an enlarged view used as the polarizing plate 31.

Next, members other than the present polarizing film 31 (the original polarizing plate 110) of the EL display device 30 will be briefly described.

As the base material 33, a ceramic base material such as a sapphire glass base material, a quartz glass base material, a soda glass base material, and an alumina; Metal substrates such as copper; And plastic substrates. Although not shown, a thermally conductive film may be formed on the substrate 33. A diamond thin film (DLC, etc.) etc. are mentioned as a heat conductive film. When the pixel electrode 35 is of a reflective type, light is emitted in a direction opposite to the substrate 33. Therefore, a transparent material as well as a non-transparent material such as stainless steel can be used. The substrate may be formed singly, or may be formed as a laminated substrate by bonding a plurality of substrates with an adhesive. Moreover, these base materials are not limited to a plate-shaped thing, You may be a film.

As the thin film transistor 40, a polycrystalline silicon transistor or the like may be used. The thin film transistor 40 is provided at the end of the pixel electrode 35, and its size is about 10 to 30 µm. In addition, the size of the pixel electrode 35 is about 20 μm × 20 μm to 300 μm × 300 μm.

The wiring electrode of the thin film transistor 40 is provided on the base material 33. The wiring electrode has a low resistance, and has a function of electrically connecting to the pixel electrode 35 to suppress the resistance value, and in general, the wiring electrode includes Al, Al and transition metals (excluding Ti), Any one or two or more of Ti or titanium nitride (TiN) is used.

An interlayer insulating film 34 is provided between the thin film transistor 40 and the pixel electrode 35. The interlayer insulating film 34 is formed by depositing an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride by sputtering or vacuum vapor deposition, a silicon oxide layer formed of SOG (spin-on-glass), photoresist, polyimide, and Any of those having insulating properties, such as a coating film of a resin-based material such as acrylic resin, may be used.

The ribs 41 are formed on the interlayer insulating film 34. The ribs 41 are arranged in the peripheral portion (between adjacent pixels) of the pixel electrode 35. Examples of the material of the rib 41 include acrylic resin and polyimide resin. The thickness of the ribs 41 is preferably 1.0 µm or more and 3.5 µm, more preferably 1.5 µm or more and 2.5 µm or less.

Next, an EL element comprising a pixel electrode 35 as a transparent electrode, an organic functional layer 36 as a light emitting source, and a cathode electrode 37 will be described. The organic functional layer 36 has at least one hole transport layer and a light emitting layer, respectively, and has, for example, an electron injection transport layer, a light emitting layer, a hole transport layer and a hole injection layer sequentially.

Examples of the pixel electrode 35 include ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), IGZO, ZnO, SnO ₂ and In ₂ O ₃ , and the like, particularly ITO or IZO. The thickness of the pixel electrode 35 may have a thickness equal to or more than a predetermined level capable of sufficiently injecting holes, and is preferably about 10 to 500 nm.

The pixel electrode 35 can be formed by a vapor deposition method (preferably a sputtering method). The sputtering gas is not particularly limited, and an inert gas such as Ar, He, Ne, Kr, and Xe, or a mixed gas of these may be used.

As the constituent material of the cathode electrode 37, metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, and Zr may be used. In order to improve the operational stability of, it is preferable to use a two-component or three-component alloy system selected from the illustrated metal elements. Examples of the alloy system include Ag · Mg (Ag: 1 to 20 at%), Al·Li (Li: 0.3 to 14 at%), In · Mg (Mg: 50 to 80 at%), and Al · Ca (Ca: 5) ∼20 at%) and the like are preferred.

The cathode electrode 37 is formed by a vapor deposition method, a sputtering method, or the like. The thickness of the cathode electrode 37 is preferably 0.1 nm or more, preferably 1 to 500 nm or more.

The hole injection layer has a function to facilitate hole injection from the pixel electrode 35, and the hole transport layer has a function of transporting holes and a function of interfering with electrons, and is also called a charge injection layer or a charge transport layer.

The thickness of the light emitting layer, the combined thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injection transport layer are not particularly limited, and vary depending on the formation method, but are preferably about 5 to 100 nm. Various organic compounds can be used for the hole injection layer and the hole transport layer. A vacuum evaporation method can be used for forming a hole injection transport layer, a light emitting layer, and an electron injection transport layer because a homogeneous thin film can be formed.

As the organic functional layer 36, which is a light emission source, using light emission (fluorescence) from singlet excitons, using light emission (phosphorescence) from triplet excitons, and light emission (fluorescence) from singlet excitons 3 Using light emission (phosphorescence) from singlet excitons, those formed by organics, those formed by organics and those formed by inorganics, polymer materials, low molecular materials, high polymer materials and low molecular materials And the like can be used. However, the present invention is not limited to this, and the organic functional layer 36 using various known ones for EL elements can be used in the present EL display device 30.

A desiccant 38 is disposed in the space between the cathode electrode 37 and the sealing lid 39. This is because the organic functional layer 36 is weak to humidity. The desiccant 38 absorbs moisture to prevent deterioration of the organic functional layer 36.

10 is a schematic diagram showing a cross-sectional configuration of another aspect of the EL display device 30. As shown in FIG. This EL display device 30 has a sealing structure using a thin film sealing film 41, and can also emit light from the opposite side of the array substrate.

As the thin film sealing film 41, it is preferable to use a DLC film obtained by depositing DLC (diamond-type carbon) on a film of an electrolytic capacitor. The DLC film has a property that water permeability is very poor, and has high moisture-proof performance. Further, a DLC film or the like may be formed by directly depositing the surface of the cathode electrode 37. Further, a thin film sealing film 41 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

As described above, a novel polarizing film (this polarizing film) and a novel display device (this liquid crystal display device and this EL display device) provided with the polarizing film according to the present invention are provided.

Finally, the projection type liquid crystal display device using this polarizing film is demonstrated.

11 is a schematic diagram showing a projection type liquid crystal display device using the present polarizing film.

As the polarizer 142 and / or the polarizer 143 of this projection type liquid crystal display device, the present polarizing film is used.

The light beam emitted from the light source (for example, a high-pressure mercury lamp) 111, which is a light emission source, is first of all, first lens array 112, second lens array 113, polarization conversion element 114, superimposition lens By passing (115), the luminance is uniformed and polarized in the cross section of the half beam.

Specifically, the light beam emitted from the light source 111 is divided into a plurality of minute light beams by the first lens array 112 in which the minute lenses 112a are formed in a matrix form. The second lens array 113 and the superimposed lens 115 are provided to irradiate the entirety of the three liquid crystal panels 140R, 140G, and 140B, each of which is a divided light beam, and thus, each liquid crystal panel incident side The surface becomes roughly uniform throughout.

The polarization conversion element 114 is constituted by a polarization beam splitter array, and is disposed between the second lens array 113 and the superposition lens 115. Accordingly, random polarization from the light source is converted into polarized light having a specific polarization direction in advance, and the light intensity loss at the incident polarizer, which will be described later, is reduced to improve the brightness of the screen.

As described above, the luminance-equalized and polarized light is sequentially red, green, and blue by dichroic mirrors 121, 123, and 132 for separating into three primary colors of RGB via the reflection mirror 122. Separated into channels, they enter the liquid crystal panels 140R, 140G, and 140B, respectively.

In the liquid crystal panels 140R, 140G, and 140B, polarizers 142 are disposed on the incident side, and polarizers 143 are disposed on the exit side, respectively. The polarizing film seen in the polarizer 142 and the polarizer 143 can be used.

The polarizer 142 and the polarizer 143 disposed in each of the RGB optical paths are arranged such that their respective absorption axes are orthogonal. Each of the liquid crystal panels 140R, 140G, and 140B disposed in each optical path has a function of converting a polarized state controlled for each pixel by an image signal into an amount of light.

The polarizing film 100 is useful as a polarizing film having excellent durability in any optical path of a blue channel, a green channel, and a red channel by selecting a type of a dichroic dye suitable for a corresponding channel.

The optical image created by transmitting incident light at a different transmittance for each pixel according to the image data of the liquid crystal panels 140R, 140G, 140B is synthesized by the cross dichroic prism 150, and the screen 180 is projected by the projection lens 170. ).

Electronic papers are those represented by molecules such as optical anisotropy and dye molecular orientation, those represented by particles such as electrophoresis, particle movement, particle rotation, and phase change, those displayed by one end of the film moving, molecules What is displayed by the color change / phase change of, what is shown by the light absorption of a molecule, and what is shown by self-lighting when electrons and holes are combined, etc. are mentioned. More specifically, microcapsule type electrophoresis, horizontally movable electrophoresis, vertically movable electrophoresis, spherical twist ball, magnetic twist ball, circumferential twist ball method, charged toner, electron powder fluid, magnetophoretic type, magneto-thermal type, electro Electrowetting, light scattering (transparency / cloudy change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, by leuco dye And fluorescence, photochromic, electrochromic, electrodeposition, and flexible organic EL. The electronic paper may be used not only for personal use of text and images, but also for advertisement display (signage) and the like. According to this polarizing film, the thickness of the electronic paper can be made thin.

As a stereoscopic display device, a method of arranging different phase difference films alternately, for example, a micropole method, has been proposed (Japanese Patent Laid-Open No. 2002-185983), but when the optical film of the present invention is used as a polarizing film, printing, Since the patterning is easy by inkjet, photolithography, or the like, the manufacturing process of the display device can be shortened, and a retardation film is not required.

Example

Hereinafter, the present invention will be described in more detail by examples. "%" And "part" in the example are mass% and mass parts unless otherwise specified.

In this example, the following polymerizable liquid crystal compound was used.

Compound (1-6) (compound represented by the following formula (1-6))

Compound (1-6) was prepared by Lub et al. Recl. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).

[Measurement of phase transition temperature]

The phase transition temperature of the compound (1-6) was confirmed by obtaining the phase transition temperature of the membrane composed of the compound (1-6). The operation is as follows.

On the alignment film formed on the glass substrate, a film made of compound (1-6) was formed, and while heating, the phase transition temperature was confirmed by texture observation with a polarizing microscope (BX-51, manufactured by Olympus). The film composed of the compound (1-6), after heating up to 120 ° C., undergoes a phase change from 112 ° C. to a nematic phase at 110 ° C., a phase change from 110 ° C. to a smectic A phase, and 94 ° C. to a smectic B phase. The phase transition was confirmed.

Compound (1-7) (compound represented by the following formula (1-7))

Compound (1-7) was synthesized with reference to the synthesis of compound (1-6) described above.

[Measurement of phase transition temperature]

The phase transition temperature of compound (1-7) was confirmed in the same manner as the phase transition temperature measurement of compound (1-6). After the compound (1-7) was heated to 140 ° C., the phase transition from 133 ° C. to the nematic phase at 133 ° C., the phase transition from 118 ° C. to the Smectic A phase, and the phase transition from 78 ° C. to the Smectic B phase. Confirmed.

Example 1

[Preparation of this composition, etc.]

The composition (polarizing film forming composition) was obtained by mixing the following components and stirring at 80 ° C for 1 hour.

Polymerizable liquid crystal compounds; Compound (1-6) 75 parts

Compound (1-7) 25 parts

Dichroic pigments; Compound (2-1-1) 2.5 parts

D10 pigment described in Japanese Patent No. 3687130

Polymerization initiators;

1-hydroxy-cyclohexyl-phenylketone

(Ilgacure 184; manufactured by Chiba Specialty Chemicals) 6 copies

Leveling agents; BYK-361N (manufactured by BYK-Chemie) 1.5 copies

Polymerizable non-liquid crystal compounds; 5.0 parts of polyfunctional acrylate (4-5)

solvent; Cyclopentanone 250 parts

[Measurement of phase transition temperature]

As in the case of compound (1-6) and compound (1-7), the phase transition temperature of the polymerizable liquid crystal compound contained in the composition prepared as described above was determined. After raising the temperature to 140 ° C., at a temperature drop, the phase transition to the nematic phase without forming a phase separation state at 109 ° C., the phase transition to the Smectic A phase without forming a phase separation state at 98 ° C., and the phase separation state at 74 ° C. It was confirmed that the phase transition was made to the Smectic B phase without formation.

[Production and evaluation of this polarizing film]

1. Formation of alignment film

A glass substrate was used as the transparent substrate.

On the glass substrate, a 2 mass% aqueous solution (a composition for forming an alignment layer) of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified, manufactured by Wako Pure Chemical Industries, Ltd.) was applied by spin coating and dried. Thereafter, a film having a thickness of 100 nm was formed. Subsequently, an alignment layer was formed by performing a rubbing treatment on the surface of the obtained film, and a polarizing film was prepared. The rubbing treatment was performed using a semi-automatic rubbing device (trade name: LQ-008 type, manufactured by Joyo Kogyo Co., Ltd.), with a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.), indentation amount 0.15. Mm, the rotational speed was 500 rpm, and the conditions were 16.7 mm / s. By this rubbing treatment, a laminate 1 having an alignment film formed on a glass substrate was obtained.

2. Formation of polarizing film

On the alignment film of the layered product (1), the composition for polarizing film formation was applied by a spin coat method, heated and dried on a hot plate at 120 ° C. for 1 minute, and then rapidly cooled to room temperature to apply the coating film on the alignment film. Formed. In such a coating film, the liquid crystal state of the polymerizable liquid crystal compound contained was Smectic B phase. Subsequently, using a UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.), ultraviolet rays are irradiated to the coating film at an exposure amount of 2000 mJ / cm 2 (based on 313 nm), thereby being included in the coating film. The polymerizable liquid crystal compound was polymerized while maintaining the liquid crystal state, and a polarizing film was prepared from the coating film. It was 1.6 micrometers when the thickness of the polarizing film at this time was measured with the laser microscope (OLS3000 by Olympus Corporation).

3. X-ray diffraction measurement

The obtained polarizing film was subjected to X-ray diffraction measurement using an X-ray diffractometer X'Pert PRO MPD (manufactured by Spectris Co., Ltd.). Using Cu as a target, X-rays generated under conditions of X-ray tube current of 40 mA and X-ray tube voltage of 45 kV are incident from the orientation direction through a fixed divergence slit 1/2 ° to 2θ in the scan range 2θ = 4.0 to 40.0 °. As a result of scanning and scanning in steps of = 0.01671 °, a sharp black peak with a peak half width (FWHM) of about 0.1718 ° was obtained at around 2θ = 20.24 °. Further, equivalent results were obtained even when incident from a direction parallel to the surface of the polarizing film and perpendicular to the orientation direction. It was found that the order period (d) obtained from the peak position was about 4.4 kHz, forming a structure reflecting the higher order smectic phase.

4. Measurement of dichroic ratio (DR)

The dichroic ratio was measured as follows.

The absorbance in the transmission axis direction (A ¹ ) and the absorption in the absorption axis direction (A ² ) at the maximum absorption wavelength are set in a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) with a polarizer attached. It was measured by a double beam method using one apparatus. In the above folder, the reference side is provided with a mesh that cuts the light amount by 50%. The ratio (A ² / A ¹ ) was calculated from the measured values of absorbance (A ¹ ) in the direction of the transmission axis and absorbance (A ² ) in the direction of the absorption axis, and used as a dichroic ratio. It can be said that the higher the dichroic ratio, the better the properties as a polarizing film. Table 1 shows the measurement results of the maximum absorption wavelength of the absorbance in the absorption axis direction (A ² ) and the dichroic ratio at that wavelength.

5. Measurement of haze value

In order to confirm the transparency of the polarizer, a haze value was measured using a haze meter (HZ-2; manufactured by Sugashi Kenki Co., Ltd.). Table 1 shows the measurement results.

In Examples 2 to 8, Reference Examples 1 and Comparative Examples 1 and 2, the composition was prepared in the same manner except that the type and content of the polymerizable non-liquid crystal compound were changed. In addition, in Comparative Example 3, a composition was prepared under conditions in which a polymerizable non-liquid crystal compound was not added, and after coating and drying at 120 ° C, the composition was quickly moved onto a hot plate at 70 ° C, and then a polarizing film was produced by UV exposure. Table 1 shows the results of each measurement.

Examples 9 to 15 were prepared in the same manner as in Example 1, except that the dichroic dye was changed to the following structural formula (2-3-1) to change the type and content of the polymerizable non-liquid crystal compound. Table 1 shows the results of each measurement.

Examples 1-15 showed good horizontal orientation and high dichroism without forming a phase separation state. Good horizontal alignment property is derived from a polymerizable liquid crystal compound showing a nematic liquid crystal phase, and high dichroism is derived from a polymerizable liquid crystal compound showing a smectic liquid crystal phase.

Industrial availability

The polarizing film can be suitably used as a display device (display) application. Therefore, the present composition capable of producing such a present polarizing film has high industrial value.

1: Transparent substrate
2: Optical alignment layer
3: This polarizing film
4: retardation layer
100: polarizer
210: first roll 210A: winding core
220: second roll 220A: winding core
230: third roll 230A: winding core
240: fourth roll 240A: winding core
211A, 211B: Applicator
212A, 212B: Drying furnace
213A: polarized UV irradiation device
213B: light irradiation device
300: auxiliary roll
10: liquid crystal display device
11: antireflection layer
12a, 12b: polarizer
13a, 13b: retardation film
14a, 14b: description
15: color filter
16: transparent electrode
17: liquid crystal layer
18: interlayer insulating film
19: backlight unit
20: black matrix
21: thin film transistor
22: pixel electrode
23: spacer
24: liquid crystal display device
30: EL display device
31: circular polarizer
33: description
34: interlayer insulating film
35: pixel electrode
36: light emitting layer
37: cathode electrode
38: desiccant
39: sealing lid
40: thin film transistor
41: rib
42: thin film sealing film
110: circular polarizer
111: light source
112: first lens array
112a: lens
113: second lens array
114: polarization conversion element
115: superposition lens
121, 123, 132: dichroic mirror
122: reflective mirror
140R, 140G, 140B: LCD panel
142, 143: polarizer
150: cross dichroic prism
170: projection lens
180: screen

Claims (13)

A composition for forming a polarizing film containing a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a polymerization initiator and a solvent, and satisfying the following requirements (A), (B), and (C):
(A) The polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound both have polymerizable groups;
(B) The polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing film does not form a phase separation state, and exhibits a nematic liquid crystal phase and a smectic liquid crystal phase; And
(C) The polymerizable non-liquid crystal compound is a monofunctional acrylate or a polyfunctional acrylate, and is contained in a ratio of 3 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. The composition for forming a polarizing film according to claim 1, wherein the polymerizable liquid crystal compound is a compound represented by the following formula (1).
U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (1)
(In the formula, X ¹ , X ² and X ³ each independently represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. However, X ¹ , At least one of X ² and X ³ is a 1,4-phenylene group which may have a substituent -CH ₂ -constituting the cyclohexane-1,4-diyl group is -O-, -S- or -NR It may be substituted with-R represents an alkyl group or a phenyl group having 1 to 6 carbon atoms Y ¹ and Y ² independently of each other -CH ₂ CH _2- , -CH ₂ O-, -COO-, -OCOO-, Represents ^a single bond, -N = N-, -CR ^a = CR ^b- , -C≡C- or -CR ^a = N- R ^a and R ^b independently of each other are a hydrogen atom or an alkyl group having 1 to 4 carbon atoms U ¹ represents a hydrogen atom or a polymerizable group U ² represents a polymerizable group W ¹ and W ² independently of each other represent a single bond, -O-, -S-, -COO- or -OCOO- V ¹ and V ² independently of one another have a substituent. It may represent an alkanediyl group having 1 to 20 carbon atoms, and -CH ₂ -constituting the alkanediyl group may be substituted with -O-, -S- or -NH-.) delete The polymerizable group of the polymerizable liquid crystal compound and the polymerizable group of the polymerizable non-liquid crystal compound are each independently an acryloyloxy group (CH ₂ = CHCOO-) or a methacryloyloxy group. (CH ₂ = C (CH ₃ ) COO-) is a composition for forming a polarizing film. The composition for forming a polarizing film according to claim 1 or 2, wherein the polymerizable group of the polymerizable liquid crystal compound and the polymerizable group of the polymerizable non-liquid crystal compound are the same. The composition for forming a polarizing film according to claim 1 or 2, wherein the polymerizable liquid crystal compound has 1 to 2 polymerizable groups in the molecule, and the polymerizable non-liquid crystal compound has 2 to 6 polymerizable groups in the molecule. delete The manufacturing method of a polarizing film which has the process of the following (I), (II) and (III).
(I) A step of applying the composition for forming a polarizing film according to claim 1 or 2 onto a substrate or an alignment film formed on a substrate, and removing a solvent to form a coating film;
(II) a step of bringing the polymerizable liquid crystal compound contained in the coating film formed in (I) into a smectic liquid crystal phase;
(III) The process of copolymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound in the coating film in which the polymerizable liquid crystal compound formed in (II) is in a smectic liquid crystal phase state. The method for manufacturing a polarizing film according to claim 8, wherein the substrate is a transparent substrate subjected to orientation treatment. The process (I-1) and the process according to claim 8, wherein the process of (II) is heat-treated until the polymerizable liquid crystal compound contained in the coating film formed in the process of (I) exhibits a nematic liquid crystal phase. Of the polarizing film which is the process which has the process (I-2) which cools the coating film in which the polymerizable liquid crystal compound formed in (I-1) is in a nematic liquid crystal phase until the polymerizable liquid crystal compound shows a smectic liquid crystal phase. Manufacturing method. A polarizing film produced by the production method according to claim 8. The polarizing film according to claim 11, which exhibits a black peak in diffraction measurement by X-rays. A display device comprising the polarizing film according to claim 11.

Images