JP2018084845A - Composition for forming polarizing film and polarizing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for forming a polarizing film that enables production of a polarizing film that is thin and has high transparency, and a polarizing film formed from the composition for forming the polarizing film.SOLUTION: Provided are: a composition for forming a polarizing film that contains a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a photopolymerization initiator, and a solvent, and satisfies following requirements (A) and (B) and a polarizing film formed from the composition for forming the polarizing film, (A) both of the polymerizable liquid crystal compound and polymerizable non-liquid crystal compound having polymerizable groups and (B) the polymerizable liquid crystal compound included in a coating film obtained from the composition for forming the polarizing film indicating a nematic liquid crystal phase and a smectic liquid crystal phase without forming a phase separation state.SELECTED DRAWING: None

Description

  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 method for producing the same, and the like.

In recent years, liquid crystal display devices are strongly required to be thin, and accordingly, a polarizer used in the liquid crystal display device is also required to be thinner. In order to realize a thinner polarizer, the polarizing film used in the liquid crystal display device is formed from a composition containing a polymerizable liquid crystal compound instead of the conventional film made of polyvinyl alcohol dyed with iodine. Is being considered.
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. In addition, Patent Document 2 discloses a polarizing film comprising only a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator, an inhibitor, a gelling agent, and a solvent.

Japanese Patent No. 4719156 Special table 2008-547062 gazette

However, further thinning of the polarizing film and high transparency have been demanded.
The objective of this invention is providing the polarizing film formed from the composition for polarizing film formation which can manufacture the polarizing film which is thin and highly transparent, and the said composition for polarizing film formation.

The present invention provides the following inventions.
[1] A composition for forming a polarizing film, which 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) Both the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound have a polymerizable group;
(B) The polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing film exhibits a nematic liquid crystal phase and a smectic liquid crystal phase without forming a phase separation state (these (A) and (B) Each of the requirements is 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 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 are each independently a 1,4-phenylene group which may have a substituent or cyclohexane-1,4-diyl which may have a substituent. Wherein at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent, a cyclohexane-1,4-diyl group; The constituent —CH ₂ — may be replaced by —O—, —S— or —NR—, wherein R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and Y ¹ and Y ² are independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C- or -CR ^a = the .R ^a and ^{R b} represents an N-, independently of one another, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms ^.U-1 representing the ^.U-2 represents a hydrogen atom or a polymerizable group, .W ¹ and ^{W 2} represents a polymerizable group, independently of one another, a single bond, -O -, - S -, - COO- Or represents —OCOO—, V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group. May be replaced by —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₎ COO-) is [1] to the polarization film forming composition according to any one of [3].
[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 is the same as the polymerizable group of the polymerizable non-liquid crystal compound.
[6] 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. The composition for forming a polarizing film according to any one of the above.
[7] The polarizing film formation 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. Composition.
[8] A method for producing a polarizing film comprising the following steps (I), (II) and (III):
(I) The polarizing film forming composition according to any one of [1] to [7] is applied on a substrate or an alignment film formed on the substrate, and the solvent is removed to form a coating film. The step of:
(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) A step of copolymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound in a coating film formed in (II) in which the polymerizable liquid crystal compound is in a smectic liquid crystal phase.
[9] The method for producing a polarizing film according to [8], wherein the base material is a transparent base material subjected to an alignment treatment.
[10] The step (II) includes a step (I-1) in which heat treatment is performed until the polymerizable liquid crystal compound contained in the coating film formed in the step (I) exhibits a nematic liquid crystal phase; And 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 state until the polymerizable liquid crystal compound exhibits a smectic liquid crystal phase [8] ] Or 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 exhibits a Bragg peak in X-ray diffraction measurement.
[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.

It is a schematic diagram which shows the principal part of the continuous manufacturing method (Roll to Roll format) of the polarizing film of this invention. It is a schematic diagram which shows the cross-sectional structure of the liquid crystal display device using the polarizer containing the polarizing film of this invention. It is a schematic diagram which shows the layer order of the polarizer containing the polarizing film of this invention provided in the liquid crystal display device. It is a schematic diagram which shows the layer order of the polarizer containing the polarizing film of this invention provided in the liquid crystal display device. It is a schematic diagram which shows the structure of the liquid crystal display device (in-cell form) using the polarizer containing the polarizing film of this invention. It is a cross-sectional schematic diagram of the circularly-polarizing plate containing the polarizing film of this invention. It is a schematic diagram of the continuous manufacturing method of the circularly-polarizing plate containing the polarizing film of this invention. It is a schematic diagram which shows the structure of the EL display apparatus using the circularly-polarizing plate containing the polarizing film of this invention. It is a schematic diagram which shows the layer order of the circularly-polarizing plate containing the polarizing film of this invention provided in EL display apparatus. It is a schematic diagram which shows the structure of the EL display apparatus using the circularly-polarizing plate containing the polarizing film of this invention. It is a schematic diagram which shows the structure of the projection-type liquid crystal display device using the polarizer containing the polarizing film of this invention.

<Polarization film forming composition>
The composition for forming a polarizing film of the present invention (hereinafter sometimes referred to as “the present composition”) comprises a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a dichroic dye, a polymerization initiator, and a solvent. contains. A polarizing film (hereinafter, sometimes referred to as “the present polarizing film”) formed from the present composition by a production method described later is not only suitable for a liquid crystal display device but also a circularly polarizing plate suitable for an organic EL display device. (Hereinafter, referred to as “the present circularly polarizing plate” in some cases). First, the composition will be described.

<Polymerizable liquid crystal compound>
The polymerizable liquid crystal compound contained in the composition for forming a polarizing film of the present invention is a nematic liquid crystal having a polymerizable group and forming a phase separation state in a coating film formed from the composition. It is a liquid crystal compound provided with the characteristic which shows a phase and a smectic liquid crystal phase.

  Whether or not the coating film formed from the present composition satisfies (Requirement B) can be confirmed, for example, as follows. The composition is applied to a glass substrate, and the solvent is removed by subjecting the applied composition to a heat treatment and / or a reduced pressure treatment under conditions where the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound are not polymerized. Subsequently, the coating film formed on the glass substrate is heated to check whether the polymerizable liquid crystal compound contained in the coating film exhibits a nematic liquid crystal phase without phase separation. Subsequently, the heated coating film is gradually cooled to check whether the polymerizable liquid crystal compound contained in the coating film exhibits a smectic liquid crystal phase without phase separation. The nematic liquid crystal phase and the smectic liquid crystal phase can be confirmed by, for example, texture observation with a polarizing microscope, X-ray diffraction measurement, or differential scanning calorimetry. Confirmation of the formation of phase separation can be performed, for example, by surface observation with various microscopes or measurement of the degree of scattering with a haze meter.

  The smectic liquid crystal phase exhibited by the polymerizable liquid crystal compound is more preferably a higher order smectic phase. The higher-order smectic phase here means a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, and a smectic L phase. Among them, a smectic B phase, a smectic F phase, and a smectic I phase are more preferable. When the smectic liquid crystal phase exhibited by the polymerizable liquid crystal compound is a higher order smectic phase, the polarizing film having a higher degree of alignment order can be produced. In addition, the polarizing film having such a high degree of orientational order can obtain a Bragg 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 at which a phase transition from a nematic liquid crystal phase to a smectic liquid crystal phase is 40 to 200 ° C. is preferable, and a compound having a temperature of 60 to 140 ° C. is more preferable.

As a preferable polymerizable liquid crystal compound, for example, a compound represented by the formula (1) (hereinafter sometimes referred to as “compound (1)”) may be mentioned.

^{U 1 -V 1 -W 1 -X 1} -Y 1 -X 2 -Y 2 -X 3 -W 2 -V 2 -U 2 (1)
[In 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 one 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 replaced by —O—, —S— or —NR—. R represents a C1-C6 alkyl group or a phenyl group.
Y ¹ and ^{Y 2,} independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C— or —CR ^a ═N— is represented. R ^a and R ^b each independently 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 each independently represent a single bond, —O—, —S—, —COO— or —OCOO—.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, — S- or -NH- may be substituted. ]

In the compound (1), it is preferable that at least ^{two of} X ¹ , X ² and X ³ are 1,4-phenylene groups which may have a substituent.
The 1,4-phenylene group which may have a substituent is preferably unsubstituted. The cyclohexane-1,4-diyl group which may have a substituent is preferably a trans-cyclohexane-1,4-diyl group which may have a substituent. It is preferable that the trans-cyclohexane-1,4-diyl group which may have a non-substituted group.

  Examples of the substituent that the optionally substituted 1,4-phenylene group or the optionally substituted cyclohexane-1,4-diyl group include a methyl group, an ethyl group, and C1-C4 alkyl groups, such as a butyl group; A cyano group; A halogen atom etc. are mentioned.

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 both are preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that receives energy from light and participates in polymerization. A polymerizable liquid crystal compound having a photopolymerizable group is also advantageous in that it can be polymerized under a lower temperature condition. As the photopolymerizable group, a radical polymerizable group is preferable. The radical polymerizable group means a group that can participate in a polymerization reaction by an active radical generated from a polymerization initiator described later.

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

Examples of the alkanediyl group of V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl group and icosane And a -1,20-diyl group. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably alkanediyl groups having 6 to 12 carbon atoms.
Examples of the substituent that the optionally substituted alkanediyl group having 1 to 20 carbon atoms has include a cyano group and a halogen atom. The alkanediyl group may be unsubstituted. It is preferably an unsubstituted and straight-chain alkanediyl group.

W ¹ and W ² are independently of each other, preferably a single bond or —O—.

  Specific examples of compound (1) include compounds represented by formula (1-1) to formula (1-23), respectively. When a specific example of the compound (1) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

The polymerizable liquid crystal compounds can be used in the present composition alone or in admixture of two or more.
When mixing 2 or more types, at least 1 type is preferable in it being a compound (1), and 2 or more types are more preferable in it being a compound (1). When mixing two kinds of polymerizable liquid crystal compounds, the mixing ratio is usually 1:99 to 50:50, preferably 5:95 to 50:50, more preferably 10:90 to 50:50. It is.

  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 contained in the composition. It is preferable to obtain the smectic phase transition temperature of the polymerizable liquid crystal compound in advance and adjust the components other than the polymerizable liquid crystal compound so that the composition is polymerized under a temperature condition lower than the phase transition temperature. When the composition contains two or more polymerizable liquid crystal compounds, the smectic phase transition temperature of the mixture of the two or more polymerizable liquid crystal compounds is obtained 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) The compounds represented by formula (1-13), formula (1-14) and formula (1-15) are preferred. These compounds easily retained the liquid crystal state of a high-order smectic phase easily under temperature conditions below the smectic phase transition temperature due to the interaction with other polymerizable liquid crystal compounds or polymerizable non-liquid crystal compounds. As it is, it can be polymerized.

  The content ratio of the polymerizable liquid crystal compound in the composition is usually 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 100 parts by mass of the solid content of the composition. It is 80-94 mass parts, More preferably, it is 80-90 mass parts. If the content rate of a compound (1) is in the said range, there exists a tendency for the orientation of the compound (2) mentioned later to become high, and it is preferable. Here, solid content means the total amount of the component remove | excluding the solvent from this composition.

  Polymerizable liquid crystal compounds are described in, for example, Lub et al. Recl. Trav. Chim. It is manufactured by a known method 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 having a polymerizable group and having no liquid crystal state between a solid and a liquid even when the temperature changes.

  The polymerizable non-liquid crystal compound has (i) no coloration (absorption with respect to visible light) itself, (ii) compatibility with a degree of uniform mixing with the polymerizable liquid crystal compound, and (iii) polymerizability. It is preferable that formation of a liquid crystal state exhibited by the liquid crystal compound is not inhibited.

  Examples of the polymerizable non-liquid crystal compound include monofunctional acrylates and polyfunctional acrylates. Monofunctional means having one polymerizable group, and 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 contained in the polymerizable non-liquid crystal compound is preferably 1 to 6, and more preferably 2 to 6.

The polymerizable group possessed by the polymerizable non-liquid crystal compound is preferably the same as the polymerizable group possessed by the polymerizable liquid crystal compound.
In addition, when at least one compound selected from a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound has plural kinds of polymerizable groups, at least one polymerizable group included in the polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound It is preferable that at least one polymerizable group possessed by is the same.

More preferable polymerizable non-liquid crystal compounds have the characteristics (i), (ii) and (iii) described above, and have 1 to 6, preferably 2 to 6 polymerizable groups in the molecule. And monofunctional acrylates and polyfunctional acrylates. In addition, since this monofunctional acrylate and polyfunctional acrylate are non-liquid crystalline, what does not have a mesogenic structure is preferable.
In addition, the polymerizable liquid crystal compound contained in the coating film obtained from this composition has a urethane structure, amino structure, epoxy structure, ethylene glycol structure and polyester structure in the molecule as long as the nematic liquid crystal phase and smectic liquid crystal phase are not disturbed. It may be included.

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

The monofunctional acrylate is a group selected from the group consisting of an acryloyloxy group (CH ₂ ═CH—COO—) and a methacryloyloxy group (CH ₂ ═C (CH ₃ ) —COO—) (hereinafter referred to as (meth) acryloyloxy). In some cases, it is a compound having one in the molecule. When the polymerizable non-liquid crystal compound is a monofunctional acrylate, the polymerizable liquid crystal compound preferably 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 alkylation having 2 to 14 carbon atoms. Examples include phenyl (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, the polymerizable liquid crystal compound also preferably has a (meth) acryloyloxy group.

  As the bifunctional acrylate having two (meth) acryloyloxy groups, 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; bisphenol A Bis (acryloyloxyethyl) ether; ethoxylated bisphenol A di (meth) acrylate; propoxylated neopentyl glycol di (meth) acrylate; ethoxylated neopentylglycol And di (meth) acrylate and 3-methyl-pentanediol di (meth) acrylate.

As the polyfunctional acrylate having 3 to 6 (meth) acryloyloxy groups,
Trimethylolpropane tri (meth) acrylate; pentaerythritol tri (meth) acrylate; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; ethoxylated trimethylolpropane tri (meth) acrylate; propoxylated trimethylolpropane tri ( Pentaerythritol tetra (meth) acrylate; dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate; tripentaerythritol tetra (meth) acrylate; tripentaerythritol penta (meth) acrylate; tripenta Erythritol hexa (meth) acrylate; tripentaerythritol hepta (meth) acrylate; tripentaerythritol o Data (meth) acrylate;
Reaction product of pentaerythritol tri (meth) acrylate and acid anhydride; Reaction product of dipentaerythritol penta (meth) acrylate and acid anhydride;
A reaction product of tripentaerythritol hepta (meth) acrylate and an 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 tripentaerys Tall hepta (meth) acrylate; caprolactone-modified tripentaerythritol octa (meth) acrylate; reaction product of caprolactone-modified pentaerythritol tri (meth) acrylate and acid anhydride; caprolactone-modified dipentaerythritol penta (meth) acrylate and acid anhydride And a reaction product of the above, and caprolactone-modified tripentaerythritol hepta (meth) acrylate and an acid anhydride. In addition, in the specific example of the polyfunctional acrylate shown here, (meth) acrylate means an acrylate or a methacrylate. The caprolactone modification means that a ring-opened product of caprolactone or a ring-opened polymer is introduced between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyloxy group.

A commercial item can also be used for this polyfunctional acrylate.
Such commercially available products include 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", "M-325", "M-240", "M-270", "M-309", "M-310", "M-321", "M-350""M-360","M-305","M-306","M-450","M-451","M-408","M-400""M-402","M-403","M-404","M-4" 5 ”,“ M-406 ”(manufactured by Toa Gosei Co., Ltd.),“ EBECRYL11 ”,“ 145 ”,“ 150 ”,“ 40 ”,“ 140 ”,“ 180 ”, DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA, TMPTA, TMPEOTA, DPHA, EBECRYL series (manufactured by Daicel Cytec Co., Ltd.) and the like can be mentioned.

Preferable 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 composition is usually 0.1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 3% with respect to the total mass of the composition. -7% by mass. More preferably, it is 0.1-19 mass parts with respect to 100 mass parts of solid content of this composition, More preferably, it is 1-15 mass parts, Most preferably, it is 4-10 mass parts. Furthermore, it is especially preferable that they are 3 mass parts or more and 10 mass parts or less with respect to 100 weight part of polymeric liquid crystal compounds. If the content of the polymerizable non-liquid crystal compound is within the above range, the polymerizable component (polymerizability) in the composition can be obtained without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the composition. A liquid crystal compound and a polymerizable non-liquid crystal compound) can be copolymerized, which is preferable. Although depending on the type of each of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound, if 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 dye>
A dichroic dye refers to a dye having the property that the absorbance in the major axis direction of a molecule is different from the absorbance in the minor axis direction. As long as it has such properties, the dichroic dye may be a dye or a pigment, or may be a mixture of a plurality of compounds.

  As said dichroic dye, what has a maximum absorption wavelength ((lambda) MAX) in the range of 300-700 nm is preferable. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, and among them, azo dyes are preferable. Examples of the azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred.

Examples of the azo dye include a compound represented by the formula (2) (hereinafter sometimes referred to as “compound (2)”).
_{^{A 1 (-N = N-A}} 2) p -N = N-A 3 (2)
[In Formula (2),
A ¹ and A ³ are each independently 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. Represents. 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 ring which may have a substituent. Represents a group. p represents an integer of 1 to 4. When p is an integer greater than or equal to ² , several A2 may mutually be same or different. ]

  Examples of the monovalent heterocyclic group include groups in which one hydrogen atom has been removed from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole and benzoxazole. A group obtained by removing two hydrogen atoms from a heterocyclic compound corresponds to a divalent heterocyclic group, and specific examples of the heterocyclic compound are as described above.

As a substituent which the phenyl group, naphthyl group and monovalent heterocyclic group in A ¹ and A ³ and the p-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ² optionally have Is an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group and a butoxy group; a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; Nitro group; halogen atom; substituted or unsubstituted amino group such as amino group, diethylamino group and pyrrolidino group (substituted amino group is an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or two This means an amino group in which substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, and the unsubstituted amino group is —NH ₂ . In addition, the specific example of a C1-C6 alkyl group is the same as what was illustrated with the substituent which the phenylene group etc. of a compound (1) have arbitrarily.

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

［式（２−１）〜（２−６）中、
Ｂ^１〜Ｂ^２０は、互いに独立に、水素原子、炭素数１〜６のアルキル基、炭素数１〜４のアルコキシ基、シアノ基、ニトロ基、置換又は無置換のアミノ基（置換アミノ基及び無置換アミノ基の定義は前記のとおり）、塩素原子又はトリフルオロメチル基を表す。
ｎ１〜ｎ４は、互いに独立に０〜３の整数を表す。
ｎ１が２以上である場合、複数のＢ^２は互いに同一でも異なっていてもよく、
ｎ２が２以上である場合、複数のＢ^６は互いに同一でも異なっていてもよく、
ｎ３が２以上である場合、複数のＢ^９は互いに同一でも異なっていてもよく、
ｎ４が２以上である場合、複数のＢ¹⁴は互いに同一でも異なっていてもよい。］

[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, a substituted or unsubstituted amino group (a substituted amino group and As defined above, the unsubstituted amino group represents a chlorine atom or a trifluoromethyl group.
n1 to n4 each independently represents an integer of 0 to 3.
when n1 is 2 or more, the plurality of B ² may be the same as or different from each other;
when n2 is 2 or more, the plurality of B ⁶ may be the same as or different from each other;
when n3 is 2 or more, the plurality of B ⁹ may be the same as or different from each other;
When n4 is 2 or more, the plurality of B ¹⁴ may be the same as or different from each other. ]

［式（２−７）中、
Ｒ^１〜Ｒ^８は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘ又はハロゲン原子を表す。
Ｒ^ｘは、炭素数１〜４のアルキル基又は炭素数６〜１２のアリール基を表す。］ As said anthraquinone pigment | dye, the compound represented by Formula (2-7) is preferable.

[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. ]

［式（２−８）中、
Ｒ^９〜Ｒ^１５は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘ又はハロゲン原子を表す。
Ｒ^ｘは、炭素数１〜４のアルキル基又は炭素数６〜１２のアリール基を表す。］ As the oxazone dye, a compound represented by the formula (2-8) is preferable.

[In the formula (2-8),
R ^{9 to} R ¹⁵ 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. ]

［式（２−９）中、
Ｒ^１６〜Ｒ^２３は、互いに独立に、水素原子、−Ｒ^ｘ、−ＮＨ_２、−ＮＨＲ^ｘ、−ＮＲ^ｘ _２、−ＳＲ^ｘ又はハロゲン原子を表す。
Ｒ^ｘは、炭素数１〜４のアルキル基又は炭素数６〜１２のアリール基を表す。］ As the acridine dye, a compound represented by the formula (2-9) is preferable.

[In Formula (2-9),
R ¹⁶ to R ²³ independently represent a hydrogen _{^{atom, -R x, -NH 2, -NHR}} x, -NR x 2, -SR x , or 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 formula (2-7), formula (2-8), and formula (2-9), the alkyl group having 1 to 4 carbon atoms represented by R ^x includes a methyl group, an ethyl group, a propyl group, and a butyl group. , A pentyl group, and a hexyl group. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xylyl group, and a naphthyl group.

［式（２−１０）中、
Ｄ^１及びＤ^２は、互いに独立に、式（２−１０ａ）〜式（２−１０ｄ）のいずれかで表される基を表す。

ｎ５は１〜３の整数を表す。］ As the cyanine dye, a compound represented by the formula (2-10) and a compound represented by the formula (2-11) are preferable.

[In the formula (2-10),
D ¹ and D ² each independently represent a group represented by any one of formulas (2-10a) to (2-10d).

n5 represents an integer of 1 to 3. ]

［式（２−１１）中、
Ｄ^３及びＤ^４は、互いに独立に、式（２−１１ａ）〜式（２−１１ｈ）のいずれかで表される基を表す。

ｎ６は１〜３の整数を表す。］

[In the formula (2-11),
D ³ and D ⁴ each independently represent a group represented by any one of formulas (2-11a) to (2-11h).

n6 represents an integer of 1 to 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, and 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable liquid crystal compound. Is more preferably 0.1 parts by mass or more and 10 parts by mass or less, and particularly preferably 0.1 parts by mass or more and 5 parts by mass or less. If the content of the dichroic dye is within this range, the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be obtained without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the present composition. Is preferable because it can be polymerized. When there is too much content of a dichroic dye, there exists a possibility of inhibiting the orientation of a polymerizable liquid crystal compound. Therefore, the content of the dichroic dye can be determined within a range in which the polymerizable liquid crystal compound can maintain the liquid crystal state.

  A commercially available dichroic dye can be used.

<Polymerization initiator>
The present composition contains a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction such as a polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator capable of generating an active radical 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 the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl). ) Benzophenone and 2,4,6-trimethylbenzophenone.

  Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) Butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1 -[4- (2-hydroxyethoxy) phenyl] propan-1-one, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1- ON oligomers.

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

  Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxy Naphthyl) -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 (trichloro Methyl)- - such as [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

  A commercially available polymerization initiator can be used. Commercially available polymerization initiators include “Irgacure 907”, “Irgacure 184”, “Irgacure 651”, “Irgacure 819”, “Irgacure 250”, “Irgacure 369” (Ciba Japan Co., Ltd.); “Sake All BZ”, “Sake All Z”, “Sake All BEE” (Seiko Chemical Co., Ltd.); “Kayacure BP100” (Nippon Kayaku Co., Ltd.); “Kayacure UVI-6992” (Dow) "Adekaoptomer SP-152", "Adekaoptomer SP-170" (ADEKA); "TAZ-A", "TAZ-PP" (Nihon Shibel Hegner); and "TAZ-104" (Sanwa Chemical) Companies).

  The content of the polymerization initiator in the composition can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 to 100 parts by mass of the polymerizable liquid crystal compound content. 30 parts by mass. Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. If the content of the polymerization initiator is within this range, the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be used together without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the composition. This is preferable because it can be polymerized.

<Solvent>
The present composition contains a solvent. As the solvent, a solvent capable of completely dissolving the polymerizable liquid crystal compound, the polymerizable non-liquid crystal compound and the dichroic dye is preferable. Moreover, it is preferable that it is a solvent inactive to the polymerization reaction in this composition.
Solvents 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; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone Or ester solvents such as 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; toluene And aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile; Hydrofuran and ether solvents such as dimethoxyethane; and chloroform and chlorine-containing solvents such as chlorobenzene; and the like. These solvents may be used alone or in combination.

  As for content of a solvent, 50-98 mass% is preferable with respect to the total amount of this composition. In other words, the solid content in the composition is preferably 2 to 50% by mass. It is preferable that the solid content is 2% by mass or more because the polarizing film tends to be obtained. Further, when the solid content is 50% by mass or less, the viscosity of the present composition is lowered, so that the thickness of the polarizing film becomes substantially uniform, and thus there is a tendency that unevenness is less likely to occur in the polarizing film. preferable. Further, the solid content can be determined in consideration of the thickness of the polarizing film to be manufactured.

  The present 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.

<Polymerization reaction aid>
The present composition may further contain a sensitizer. As the sensitizer, a photosensitizer is preferable. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone and 2-isopropylthioxanthone); anthracene such as anthracene and alkoxy group-containing anthracene (for example, dibutoxyanthracene). Compounds; phenothiazine, rubrene and the like.

  When this 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 accelerated. The amount of the sensitizer used 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 with respect to a total of 100 parts by mass of the polymerizable liquid crystal compound. Is more preferable.

  In order to allow the polymerization reaction to proceed stably, the present composition may contain an appropriate amount of a polymerization inhibitor. By containing the polymerization inhibitor, it is possible to control the progress of the polymerization reaction of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound.

  Examples of the polymerization inhibitor include radicals such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (eg, butyl catechol), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical, and the like. Supplementary agents; thiophenols; β-naphthylamines and β-naphthols.

  When the polymerization inhibitor is contained in the composition, the content of the polymerization inhibitor is preferably from 0.1 to 30 parts by mass, and from 0.5 to 10 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. Is more preferable, and 0.5-8 mass parts is further more preferable. If the content of the polymerization inhibitor is within this range, the polymerizable liquid crystal compound can be polymerized without disturbing the orientation of the polymerizable liquid crystal compound contained in the polarizing film forming composition. Furthermore, it is possible to polymerize while maintaining a good liquid crystal state.

<Leveling agent>
The composition preferably contains a leveling agent. The leveling agent has a function of adjusting the fluidity of the composition and making the coating film obtained by applying the composition more flat, and examples thereof include a surfactant. The leveling agent is more preferably at least one selected from the group consisting of a leveling agent having a polyacrylate compound as a main component and a leveling agent having a fluorine atom-containing compound as a main component. In addition, the polyacrylate compound here does not have a polymeric group.

  Leveling agents mainly composed of polyacrylate compounds include “BYK-350”, “BYK-352”, “BYK-353”, “BYK-354”, “BYK-355”, “BYK-358N”, “ BYK-361N ”,“ BYK-380 ”,“ BYK-381 ”,“ BYK-392 ”[BYK Chemie], and the like.

  Leveling agents mainly composed of fluorine atom-containing compounds include "Megafac R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-482" and the same "F-483" [DIC Corporation]; "Surflon S-381", "S-382", "S-383", "S-393", "SC-101", "SC" -105 "," KH-40 "and" SA-100 "[AGC Seimi Chemical Co., Ltd.];" E1830 "," E5844 "[Daikin Fine Chemical Laboratory Co., Ltd.];" F-top EF301 "," EF303 " ", EF351" and "EF352" [Mitsubishi Materials Child Kasei Co., Ltd.] and the like.

  When the leveling agent is contained in the composition, the content is preferably 0.3 parts by mass or more and 5 parts by mass or less, and 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. Is more preferable. It is preferable that the content of the leveling agent is within the above range because the polymerizable liquid crystal compound can be easily horizontally aligned and the obtained polarizing film tends to be smoother. If the content of the leveling agent with respect to the polymerizable liquid crystal compound exceeds the above range, the obtained polarizing film tends to be uneven, which is not preferable. In addition, this composition may contain 2 or more types of leveling agents.

<Formation method of this polarizing film>
Next, a method for forming the polarizing film from the composition will be described. First, this composition is apply | coated on the orientation film | membrane formed on the base material or the base material. Preferably, it coats on the orientation film formed on the substrate. A transparent substrate is preferable as the substrate.

<Transparent substrate>
The transparent base material is a base material having transparency to the extent that light, particularly visible light can be transmitted. The transparency refers to a characteristic that the transmittance with respect to a light beam having a wavelength of 380 to 780 nm is 80% or more. Specific examples of such a transparent substrate include a glass substrate and a plastic substrate. Examples of the plastic constituting the plastic substrate include polyolefins such as polyethylene, polypropylene and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid esters; polyacrylic acid esters; Examples include cellulose esters such as diacetylcellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; and plastics such as polyphenylene sulfide and polyphenylene oxide. Among these, cellulose ester, cyclic olefin resin, polycarbonate, polyethylene terephthalate or polymethacrylic acid ester are particularly preferable from the viewpoint that they can be easily obtained from the market or have excellent transparency. In producing the polarizing film using such a transparent substrate, the transparent substrate can be easily handled without causing damage such as tearing when the transparent substrate is transported or stored. A support base material or the like may be pasted. Moreover, although mentioned later, when manufacturing a circularly-polarizing plate from this polarizing film, retardation may be provided to a plastic base material. In this case, the phase difference may be imparted to the plastic substrate by stretching treatment or the like. The method for imparting retardation to the transparent substrate will be described later.

The cellulose ester is one in which at least a part of the hydroxyl group contained in cellulose is converted to acetic acid ester. A cellulose ester film comprising such a cellulose ester can be easily obtained from the market. Examples of commercially available triacetyl cellulose films include “Fujitac Film” (Fuji Photo Film Co., Ltd.); “KC8UX2M”, “KC8UY” and “KC4UY” (Konica Minolta Opto Co., Ltd.).
Such a commercially available triacetyl cellulose film can be used as a transparent substrate as it is or after imparting retardation as necessary. The surface of the prepared transparent substrate can be used as a transparent substrate after being subjected to surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment or antireflection treatment.

  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 a polycyclic norbornene-based monomer, and the cyclic olefin-based resin is partially The ring-opening part may be included. Moreover, what hydrogenated the cyclic olefin resin containing a ring opening part may be used. Further, the cyclic olefin resin is, for example, a copolymer of a cyclic olefin and a chain olefin or a vinylated aromatic compound (such as styrene) in that the transparency is not significantly impaired or the hygroscopicity is not significantly increased. It may be. The cyclic olefin resin may have a polar group introduced in its 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, propylene, or the like, and a vinylated aromatic Examples of the compound include styrene, α-methylstyrene, and alkyl-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% with respect to all the structural units of the cyclic olefin resin. When the cyclic olefin-based resin is a terpolymer 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 the cyclic olefin. It is about 5-80 mol% with respect to all the structural units of a resin, and the content rate of the structural unit derived from a vinylated aromatic compound is about 5-80 mol%. Such a terpolymer cyclic olefin resin has the advantage that the amount of expensive cyclic olefin used can be relatively reduced when the cyclic olefin resin is produced.

  Cyclic olefin resin is easily available from the market. Commercially available cyclic olefin-based resins include “Topas” [Ticona (Germany)]; “Arton” [JSR Corporation]; “ZEONOR” and “ZEONEX” [Nippon Zeon Corporation] “Apel” [Mitsui Chemicals, Inc.] and the like. Such a cyclic olefin-based resin can be formed into a film (cyclic olefin-based resin film) by, for example, known film forming means such as a solvent casting method or a melt extrusion method. Moreover, the cyclic olefin resin film already marketed with the form of a film can also be used. Examples of such commercially available cyclic olefin-based resin films include “Essina” and “SCA40” [Sekisui Chemical Co., Ltd.]; “Zeonor Film” [Optes Corporation]; “Arton Film” [JSR Corporation] ] Etc. are mentioned.

  Next, a method for imparting retardation to a plastic substrate will be briefly described. The plastic substrate can be provided with retardation by a known stretching method. For example, a roll (winding body) in which a plastic substrate is wound around a roll is prepared, the plastic substrate is continuously unwound from the wound body, and the unrolled plastic substrate is transferred to a heating furnace. And carry. The set temperature of the heating furnace is in the range of near the glass transition temperature of the plastic substrate (° C.) to [glass transition temperature +100] (° C.), preferably near the glass transition temperature (° C.) to [glass transition temperature +50] (° C. ). In the heating furnace, when stretching in the direction of travel of the plastic substrate, or in the direction perpendicular to the direction of travel, the transport direction and tension are adjusted, and an arbitrary angle is added to the uniaxial or biaxial thermal stretching process. I do. The draw ratio is usually in the range of about 1.1 to 6 times, preferably in the range of about 1.1 to 3.5 times. In addition, the method of stretching in an oblique direction is not particularly limited as long as the orientation axis can be continuously inclined to a desired angle, and a known stretching method can be employed. Examples of such a stretching method include the methods described in JP-A-50-83482 and JP-A-2-113920.

  The thickness of the transparent substrate is preferably thin in terms of weight that allows practical handling and sufficient transparency, but if it is too thin, the strength decreases and the processability is poor. Tend. An appropriate thickness of the glass substrate is, for example, about 100 to 3000 μm, and preferably 100 to 1000 μm. An appropriate 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 circularly polarizing plate, which will be described later, the thickness of the transparent substrate is preferably thinner especially when used as a circularly polarizing plate for mobile devices, and the thickness in the case of a glass substrate is 100 to 500 μm. The thickness is preferably about 20 to 100 μm. In addition, when providing phase difference to a plastic base material by extending | stretching, the thickness after extending | stretching is determined by the thickness before extending | stretching and a draw ratio.

<Alignment film>
An alignment film is preferably formed on the base material used for the production of the polarizing film. In that case, this composition will be apply | coated on alignment film. For this reason, it is preferable that the alignment film has a solvent resistance that does not dissolve when the composition is applied. Moreover, it is preferable to have heat resistance in the heat treatment for removing the solvent and aligning the liquid crystal. Such an alignment film can be formed using an alignment polymer.

  Examples of the orientation polymer include polyamides and gelatins having an amide bond in the molecule, polyimides having an imide bond in the molecule, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyacrylamide which are hydrolysates thereof. Mention may be made of polymers such as oxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. These alignment polymers forming the alignment film may be used alone or in combination of two or more.

  The alignment polymer can be formed on the substrate by applying the alignment polymer on the substrate as an alignment polymer composition (solution containing the alignment polymer) dissolved in a solvent. 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; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Ester solvents such as 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; toluene and Aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxyethane Chlorinated hydrocarbon solvent of chloroform and chlorobenzene; an ether solvent like, and the like. These organic solvents may be used alone or in combination of two or more.

  A commercially available alignment film material may be used as it is as the alignment polymer composition for forming the alignment film. Examples of commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.) and Optmer (registered trademark, manufactured by JSR).

  As a method for forming an alignment film on the substrate, for example, the alignment polymer composition or a commercially available alignment film material is applied on the substrate, and then annealed to align on the substrate. A film can be formed. 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 alignment regulating force to the alignment film, it is preferable to perform rubbing (rubbing method) as necessary. By providing the alignment regulating force, the polymerizable liquid crystal compound can be aligned in a desired direction.

  As a method of applying an alignment regulating force by a rubbing method, for example, a rubbing cloth is wound, a rotating rubbing roll is prepared, and a laminate in which a coating film for forming an alignment film is formed on a substrate is staged. And a method of bringing the alignment film-forming coating film into contact with the rotating rubbing roll by transporting it toward the rotating rubbing roll.

  A so-called photo-alignment film can also be used. The photo-alignment film is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, sometimes referred to as “photo-alignment layer forming composition”) on a substrate, It refers to an alignment film in which a photo-alignment layer is formed by forming a photo-alignment-inducing layer on a substrate and irradiating polarized light (preferably, polarized UV) to impart alignment regulating force to the photo-alignment-inducing layer. The photoreactive group refers to a group that generates liquid crystal alignment ability when irradiated with light (light irradiation). Specifically, it causes photoreactions that are the origin of liquid crystal alignment ability, such as molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction caused by light irradiation. is there. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable because they are excellent in orientation and maintain a smectic liquid crystal state when a polarizing film is formed. As the photoreactive group capable of causing the above reaction, those having an unsaturated bond, particularly a double bond are preferable, and a carbon-carbon double bond (C═C bond), a carbon-nitrogen double bond (C = N bond), a group having at least one selected from the group consisting of a nitrogen-nitrogen double bond (N = N bond) and a carbon-oxygen double bond (C = O bond) is particularly preferable.

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having a structure such as an aromatic Schiff 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 a basic structure of azoxybenzene. 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 a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.
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 polarized light irradiation necessary for photoalignment, and a photoalignment layer having excellent thermal stability and temporal stability. Since it is easy to obtain, it is preferable. Further, as the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

  As the solvent for the composition for forming a photo-alignment layer, a solvent capable of dissolving a polymer and a monomer having a photoreactive group is preferable. Examples of the solvent include the solvents used in the above-described alignment polymer composition.

  The concentration of the polymer or monomer having a photoreactive group with respect to the composition for forming a photoalignment layer can be appropriately adjusted depending on the type of the polymer or monomer having the photoreactive group and the thickness of the photoalignment film to be produced. Expressed in terms of solid content concentration, it is preferably at least 0.2 mass%, particularly preferably in the range of 0.3-10 mass%. In addition, the composition may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer as long as the characteristics of the photo-alignment film are not significantly impaired.

  Examples of methods for applying the composition for forming a photo-alignment layer on a substrate include spin coating methods, extrusion methods, gravure coating methods, die coating methods, bar coating methods, applicator methods, and flexo methods A known method such as a printing method is employed. In addition, when implementing this polarizing film manufacture by the continuous manufacturing method of the Roll to Roll format mentioned later, the printing methods, such as the gravure coating method, the die coating method, or a flexo method, are employ | adopted normally.

  Note that a plurality of regions (patterns) having different orientation directions can be formed by performing masking when performing rubbing or polarized light irradiation.

<Method for producing the polarizing film>
The composition is applied onto the base material or an alignment film formed on the base material to remove the solvent to obtain a coating film. Examples of the application method (application method) include the same methods as those exemplified as the method for applying the alignment polymer or the composition for forming a photo-alignment layer on the substrate.

  Next, the coating film is formed by removing the solvent under conditions in which the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound contained in the coating film are not polymerized. Examples of the removing method include a natural drying method, a ventilation drying method, a heat drying method and a vacuum drying method. Subsequently, the polymerizable liquid crystal composition contained in the coating film exhibits a smectic liquid crystal phase. In this case, it is preferable to take advantage of the characteristics of the polymerizable liquid crystal compound to change the liquid crystal state to a nematic liquid crystal phase and then to 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 at which the nematic liquid crystal phase is exhibited or higher, and then cooled to a temperature at which the polymerizable liquid crystal compound exhibits a smectic liquid crystal phase. The method of doing is adopted.

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

  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 polymerizable liquid crystal compound contains two or more polymerizable liquid crystal compounds. It is preferable to use this composition. When this composition in which the content ratio of the two or more kinds of polymerizable liquid crystal compounds is adjusted is used, after the smectic liquid crystal phase is formed via the nematic liquid crystal phase, the liquid crystal compound temporarily exceeds the temperature at which the crystalline phase is originally exhibited. A cooling state can be formed, and there is an advantage that a liquid crystal state of a high-order smectic phase is easily maintained. When the two polymerizable liquid crystal compounds are contained, the content ratio of the two polymerizable liquid crystal compounds is usually 1:99 to 50:50, preferably 5:95 to 50:50, and more. Preferably it is 10: 90-50: 50.

Next, the polymerization process 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 the coating film with energy while maintaining the smectic liquid crystal phase. Since the present composition contains a polymerization initiator, it is preferable to irradiate energy under conditions that activate the polymerization initiator, and preferred energy includes light. As the light to be irradiated, the kind of the polymerization initiator contained in the coating film, or the kind of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound (particularly, the kind of the polymerizable group that the polymerizable liquid crystal compound has) and the amount thereof are used. Accordingly, it can be appropriately performed by light selected from the group consisting of visible light, ultraviolet light, and laser light, or an active electron beam. Among these, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that a device widely used in this field as an apparatus for polymerization can be used. Therefore, it is preferable to select the kind of the polymerizable liquid crystal compound, the polymerizable non-liquid crystal compound and the polymerization initiator contained in the composition so that the polymerization can be performed by ultraviolet light. Moreover, when superposing | polymerizing, superposition | polymerization temperature can also be controlled by cooling a coating film with a suitable cooling means with ultraviolet light irradiation. If such a cooling means can be used to polymerize the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound at a lower temperature, even if the above-mentioned base material has a relatively low heat resistance, the present polarized light can be appropriately used. There is also an advantage that a film can be formed. In the polymerization, the patterned main polarizing film can also be obtained by masking or developing.

  By performing the polymerization as described above, the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of a smectic phase, preferably a higher-order smectic phase as exemplified above, and this polarizing film is formed. This polarizing film obtained by polymerizing a polymerizable liquid crystal compound while maintaining the smectic phase liquid crystal state is a conventional host-guest type polarizing film, that is, a nematic phase liquid crystal state, due to the action of the dichroic dye. There is an advantage that the polarizing performance is high as compared with a polarizing film obtained by polymerizing a polymerizable liquid crystal compound or the like while maintaining the above. Furthermore, there is an advantage that it is excellent in strength as compared with a case where only a dichroic dye or a lyotropic liquid crystal is applied.

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

  Transparency can be evaluated by the Haze value. A preferred Haze value is 5% or less, more preferably 2% or less.

  Further, as described above, the polarizing film thus formed is particularly preferably one that can obtain a Bragg peak in X-ray diffraction measurement. As this polarizing film from which such a Bragg peak is obtained, for example, the present polarizing film showing a diffraction peak derived from a hexatic phase or a crystal phase can be mentioned.

<Continuous manufacturing method of this polarizing film>
As mentioned above, although the outline | summary 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 the Roll to Roll format, and is sometimes referred to as “the present manufacturing method”. In the present manufacturing method, the case where the substrate is a transparent substrate will be mainly described.

This manufacturing method is, for example,
Preparing a first roll in which a transparent substrate is wound around a first core;
A step of continuously feeding a transparent substrate from the first roll;
Continuously applying the composition for forming a photo-alignment layer to a transparent substrate;
Removing the solvent from the applied composition for forming a photo-alignment layer and continuously forming a first coating film on the transparent substrate;
Irradiating the coating film with polarized UV to continuously form a photo-alignment layer to form a photo-alignment film;
Continuously applying the present composition on the photo-alignment film;
A step of continuously forming a second coating film on the photo-alignment film by drying the coated present composition under conditions where the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound are not polymerized;
A step of continuously obtaining a polarizing film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal phase after the liquid crystal state of the polymerizable liquid crystal compound contained in the coating film is changed to a smectic liquid crystal phase;
A step of continuously obtaining a laminate including the transparent base material, the photo-alignment film, and the polarizing film on a second core to obtain a second roll. Here, the manufacturing method will be described with reference to FIG.

  The first roll 210 in which the transparent base material is wound around the first core 210A can be easily obtained from the market, for example. Examples of the transparent base material that can be obtained from the market in the form of such a roll include a film made of cellulose ester, cyclic olefin resin, polycarbonate, polyethylene terephthalate, or polymethacrylic acid ester, among the transparent base materials already exemplified. . In addition, when the polarizing film is used as a circularly polarizing plate, a transparent substrate previously provided with retardation is also easily available from the market, such as a retardation film made of cellulose ester, polycarbonate, or cyclic olefin resin. Is mentioned.

  Subsequently, the transparent substrate is sent out from the first roll 210. The method of feeding the transparent substrate is performed by installing an appropriate rotating means on the core 210A of the first roll 210 and rotating the first roll 210 by the rotating means. Alternatively, a suitable auxiliary roll 300 may be installed in the direction in which the transparent base material is sent out from the first roll 210, and the transparent base material may be sent out by the rotating means of the auxiliary roll 300. Further, the first winding core 210A and the auxiliary roll 300 may be provided with a rotating means so that the transparent base material is fed out while applying an appropriate tension to the transparent base material.

  When the transparent substrate sent out from the first roll 210 passes through the coating apparatus 211A, the composition for forming a photo-alignment layer is applied on the surface of the transparent base material by the coating apparatus 211A. The application device 211A for continuously applying the composition for forming a photo-alignment layer in this manner is usually a printing device that can apply a gravure coating method, a die coating method, a flexo method, or the like.

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

  The first coating film continuously formed by passing through the heating furnace 212A is then irradiated with polarized UV on the surface of the first coating film or the transparent substrate side by the polarized UV irradiation device 213A. Then, a photo-alignment layer is formed to form a photo-alignment film.

  The laminate of the base material and the photo-alignment film thus continuously formed is subsequently passed through the coating apparatus 211B so that the composition is applied onto the photo-alignment film and then passed through the drying furnace 212B. Thus, the polymerizable liquid crystal compound contained in the composition becomes a second coating film showing a smectic liquid crystal phase. The drying furnace 212B has a role of removing the solvent from the composition applied on the photo-alignment film, and the composition of the polymerizable liquid crystal compound contained in the composition so as to exhibit a smectic liquid crystal phase through a nematic liquid crystal phase. It plays the role of giving thermal energy to things. The drying furnace 212B may be capable of performing a multi-step heat treatment in order to make a smectic liquid crystal phase after making the polymerizable liquid crystal compound into a nematic liquid crystal phase. That is, the drying furnace 212B is divided into a plurality of zones, similar to the drying furnace 212A, and may be a drying furnace having a different set temperature for each of the divided zones, and the plurality of drying furnaces are arranged in series, A drying furnace having a different set temperature may be used for each drying furnace.

  The film passed through the drying oven 212B is transported to the light irradiation device 213B while the solvent contained in the composition is sufficiently removed and the polymerizable liquid crystal compound in the second coating film retains the smectic liquid crystal phase. Is done. By the light irradiation by the light irradiation device 213B, the polymerizable liquid crystal compound is photopolymerized together with the polymerizable non-liquid crystal compound while maintaining the smectic liquid crystal phase, and the polarizing film is continuously formed on the photo-alignment film.

  The polarizing film thus continuously formed is wound around the second core 220A as a laminate including the transparent base material and the photo-alignment film, and the form of the second roll 220 is obtained. When the formed polarizing film is wound up to obtain the second roll, winding using an appropriate spacer may be performed.

  In this way, the transparent base material passes through the first roll / coating device 211A / drying furnace 212A / polarized UV irradiation device 213A / coating device 211B / drying furnace 212B / light irradiation device 213B in this order. This polarizing film is continuously manufactured on the upper photo-alignment film.

  Further, in the present manufacturing method shown in FIG. 1, a method of continuously manufacturing from the transparent base material to the present polarizing film has been shown. For example, the transparent base material and the first roll / coating apparatus 211A / drying furnace 212A / By passing the polarized UV irradiation device 213A in this order, the laminate of the continuously formed substrate and the photo-alignment film is wound around the core, and the laminate is manufactured in the form of a roll. The laminate may be sent out, and the delivered laminate may be passed through the coating device 211B / drying furnace 212B / light irradiation device 213B in this order to manufacture the polarizing film.

  The polarizing film obtained by this manufacturing method has a film shape and a long shape. When this polarizing film is used for a liquid crystal display device to be described later, the polarizing film is cut into a desired size according to the scale of the liquid crystal display device.

  As mentioned above, the configuration and the manufacturing method of the present polarizing film have been described focusing on the case of the laminate of the transparent base material / the photo-alignment film / the present polarizing film. The photo-alignment film or the transparent substrate may be peeled off from the laminate, or a layer or film other than the transparent substrate / photo-alignment film / main polarizing film may be laminated. As these layers and films, as described above, the polarizing film may further include a retardation film, or may further include an antireflection layer or a brightness enhancement film.

  Moreover, it can also be set as the circularly-polarizing plate or elliptical polarizing plate of the form of retardation film / photo-alignment film | membrane / this polarizing film by making transparent base material itself into retardation film. For example, when a uniaxially stretched quarter-wave plate is used as the retardation film, by setting the irradiation direction of polarized UV to be approximately 45 ° with respect to the transport direction of the transparent substrate, Roll-to It is possible to produce a circularly polarizing plate with -Roll. Thus, as a quarter wavelength plate used when manufacturing a circularly-polarizing plate, what has the characteristic that the in-plane phase difference value with respect to visible light becomes small as a wavelength becomes short is preferable.

  Further, using a half-wave plate as a retardation film, a linear polarizing plate roll was prepared in which the angle between the slow axis and the absorption axis of the polarizing film was shifted, and the surface on which the polarizing film was formed; It is possible to form a broadband circularly polarizing plate by further forming a quarter wavelength plate on the opposite side.

<Application 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. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, an electron emission display device (for example, 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 (eg, display device having a grating light valve (GLV) display device, digital micromirror device (DMD)), and Examples of the liquid crystal display device include 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 liquid crystal display device. These display devices may be display devices that display a two-dimensional image. And it may be a stereoscopic display apparatus for displaying a three-dimensional image.
This polarizing film can be effectively used particularly for a display device of an organic electroluminescence (EL) display device or an inorganic electroluminescence (EL) display device.

2 and 5 are schematic views schematically showing a cross-sectional configuration of a liquid crystal display device (hereinafter, sometimes referred to as “the present liquid crystal display device”) 10 using the present polarizing film. The liquid crystal layer 17 is sandwiched between two bases 14a and a base material 14b.
FIG. 10 is a schematic view schematically showing a cross-sectional configuration of an EL display device using the present polarizing film (hereinafter sometimes referred to as “the present EL display device”).
FIG. 11 is a schematic diagram schematically showing a configuration of a projection type liquid crystal display device using the polarizing film.

First, the 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 across the liquid crystal layer 17, and the black matrix 20 is disposed 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.
An overcoat layer (not shown) may be provided between the color filter 15 and the transparent electrode 16.

  Thin film transistors 21 and pixel electrodes 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.

As the substrate 14a and the substrate 14b, a glass substrate and a plastic substrate are used.
As the glass substrate and the plastic substrate, the same materials as those exemplified as the transparent substrate used in the production of the polarizing film can be adopted. Moreover, the transparent base material of this polarizing film may serve as the base material 14a and the base material 14b. When manufacturing the color filter 15 and the thin film transistor 21 formed on the base material, a glass base material or a quartz base material is preferable when a step of heating to a high temperature is required.

  As the thin film transistor, an optimum one can be adopted according to 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 a plastic substrate. In order to further reduce the size of the 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. In the liquid crystal layer 17, a spacer 23 is disposed in order to keep the distance between the base material 14a and the base material 14b constant. In FIG. 2, columnar spacers are illustrated, but the spacers are not limited to columnar shapes, and the shape is arbitrary as long as the distance between the base material 14 a and the base material 14 b can be kept constant.

  Of the layers formed on the base material 14a and the base material 14b, an alignment layer for aligning the liquid crystal in a desired direction may be disposed on the surface in contact with the liquid crystal layer 17. In addition, this polarizing film can be arrange | positioned inside a liquid crystal cell, ie, this polarizing film can also be arrange | positioned in the surface side which touches the liquid-crystal layer 17. FIG. Hereinafter, such a format is referred to as an “in-cell format”.

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

Among the base material 14a and the base material 14b sandwiching the liquid crystal layer 17, the polarizers 12a and 12b are provided outside the base material 14a and the base material 14b. Among these, at least one polarizer is provided. Includes the polarizing film.
Furthermore, it is preferable that retardation layers (for example, quarter-wave plates and optical compensation films) 13a and 13b are laminated. By disposing the present polarizing film on the polarizer 12b out of the polarizers 12a and 12b, the liquid crystal display device 10 can be provided with a function of converting incident light into linearly polarized light. The retardation films 13a and 13b may not be arranged depending on the structure of the liquid crystal display device and the type of liquid crystal compound contained in the liquid crystal layer 17, and the transparent base material is a retardation film. When an (elliptical) circularly polarizing plate including a film is used, the retardation film can be used as a retardation layer, so that the retardation layers 13a and / or 13b in FIG. 2 can be omitted. A polarizing film may be further provided on the light exit side (outside) of the polarizer including the polarizing film.
Further, an antireflection film for preventing reflection of external light may be disposed outside the polarizer including the polarizing film (on the outside of the polarizing film when a polarizing film is further provided).

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

  When this polarizing film is used for the polarizer 12a or 12b, the stacking order is not particularly limited. This will be described with reference to an enlarged view of portions A and B surrounded by a dotted line in FIG.

  FIG. 3 is an enlarged schematic cross-sectional view of a portion A in FIG. 3A1 is provided such that when the polarizer 100 is used as the polarizer 12a, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 are arranged in this order from the phase difference layer 13a side. Indicates that Moreover, (A2) of FIG. 3 shows that the transparent base material 1, the photo-alignment film 2, and the present polarizing film 3 are provided in this order from the retardation layer 13a side.

  FIG. 4 is an enlarged schematic view of a portion B in FIG. 4B1 is provided such that when the polarizer 100 is used as the polarizer 12b, the transparent substrate 1, the photo-alignment film 2, and the polarizing film 3 are arranged in this order from the retardation film 13b side. . 4B2 is provided such that when the polarizer 100 is used as the polarizer 12b, the polarizing film 3, the photo-alignment film 2, and the transparent substrate 1 are arranged in this order from the retardation film 13b side. .

A backlight unit 19 serving as a light source is disposed outside the polarizer 12b.
The backlight unit 19 includes a light source, a light guide, a reflection plate, a diffusion sheet, and a viewing angle adjustment sheet. Examples of the light source include electroluminescence, a cold cathode tube, a hot cathode tube, a light emitting diode (LED), a laser light source, and a mercury lamp. In addition, the type of the polarizing film can be selected in accordance with the characteristics of such a light source.

  When the liquid crystal display device 10 is a transmissive liquid crystal display device, white light emitted from a light source in the backlight unit 19 is incident on the light guide, changed in path by a reflector, and diffused by a diffusion sheet. Yes. The diffused light is adjusted to have a desired directivity by the viewing angle adjusting sheet, and then enters the polarizer 12b from the backlight unit 19.

  Of the incident light that is non-polarized light, only one linearly polarized light passes through the polarizer 12b of the liquid crystal panel. This linearly polarized light is converted into circularly polarized light or elliptically polarized light by the retardation layer 13b, and sequentially passes through the base material 14b, the pixel electrode 22 and the like to reach the liquid crystal layer 17.

  Here, depending on the presence or absence of a potential difference between the pixel electrode 22 and the transparent electrode 16 facing the pixel electrode 22, the alignment state of the liquid crystal molecules contained in the liquid crystal layer 17 changes, and the luminance of the light emitted from the liquid crystal display device 10 is controlled. Is done. When the liquid crystal layer 17 is in an alignment state in which the polarized light is transmitted as it is, the polarized light is transmitted through the liquid crystal layer 17 and the transparent electrode 16, and light in a specific wavelength range is transmitted through the color filter 15 and reaches the polarizer 12a. Therefore, the liquid crystal display device displays the color determined by the color filter brightest.

  On the contrary, when the liquid crystal layer 17 is in an alignment state in which the polarized light is converted and transmitted, the light transmitted through the liquid crystal layer 17, the transparent electrode 16, and the color filter 15 is absorbed by the polarizer 12a. As a result, this pixel displays black. In the intermediate alignment state between these two states, the luminance of light emitted from the liquid crystal display device 10 is also intermediate between the two, so that this pixel displays an intermediate color.

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

  Next, the EL display device 30 using the polarizing film will be described with reference to FIG. When the present polarizing film is used in the present EL display device, it is preferable to use the present polarizing film after making it into a circularly polarizing plate (hereinafter sometimes referred to as “this circularly polarizing plate”). There are usually two embodiments of this circular polarizer. Therefore, before describing the configuration of the EL display device 30 and the like, two embodiments of the circularly polarizing plate will be described with reference to FIG.

  FIG. 6A is a cross-sectional view schematically showing the first embodiment of the circularly polarizing plate 110. The first embodiment is a circular polarizing plate 110 in which a retardation layer (retardation film) 4 is further provided on the polarizing film 3 in the polarizer 100. FIG. 6B is a cross-sectional view schematically showing a second embodiment of the circularly polarizing plate 110. This 2nd Embodiment uses a transparent base material 1 (retardation film 4) to which phase contrast is given beforehand as a transparent base material 1 used when manufacturing polarizer 100, so that a transparent base material is used. 1 is the circularly polarizing plate 110 having the function of the retardation layer 4 itself.

  Here, a manufacturing method of the present circularly polarizing plate 110 will be described. As described above, the second embodiment of the circularly polarizing plate 110 uses the transparent substrate 1 that has been previously provided with retardation as the transparent substrate 1, that is, the retardation film, in the manufacturing method for manufacturing the polarizing film 100. It can be manufactured by using. 1st Embodiment of the circularly-polarizing plate 110 should just form the phase difference layer 4 by bonding the retardation film on this polarizing film 3 manufactured by this manufacturing method B. FIG. When the polarizing film 100 is manufactured in the form of the second roll 220 by the manufacturing method B, the polarizing film 100 is unwound from the second roll 220, cut into a predetermined size, and then cut. Although the form which bonds a phase difference film to this this polarizing film 100 may be sufficient, a shape is a film form and a long shape by preparing the 3rd roll by which the phase difference film is wound up by the winding core. The circularly polarizing plate 110 can also be manufactured continuously.

A method for continuously manufacturing the first embodiment of the circularly polarizing plate 110 will be described with reference to FIG. Such a manufacturing method includes:
A step of continuously unwinding the polarizing film 100 from the second roll 220 and unwinding the retardation film continuously from a third roll 230 on which the retardation film is wound;
The circularly polarizing plate 110 is formed by continuously laminating the polarizing layer provided on the polarizing film 100 unwound from the second roll 220 and the retardation film unwound from the third roll. Forming, and
The present circular polarizing plate 110 thus formed is wound around the fourth core 240A to obtain the fourth roll 240.

  As mentioned above, although the manufacturing method of 1st Embodiment of this circularly-polarizing plate 110 was demonstrated, when bonding this polarizing film 3 in the polarizer 100 and retardation film, using an appropriate adhesive, The polarizing film 3 and the retardation film may be bonded via an adhesive layer formed from the adhesive.

Next, the EL display device including the circular polarizing plate 110 will be described with reference to FIG.
In the EL display device 30, an organic functional layer 36 that is a light source and a cathode electrode 37 are laminated on a base material 33 on which a pixel electrode 35 is formed. A circularly polarizing plate 31 is disposed on the opposite side of the organic functional layer 36 across the base material 33, and the circularly polarizing plate 110 is used as the circularly polarizing plate 31. 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 emits light. The organic functional layer 36 that is a light emitting source includes 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 base material 33, and the circularly polarizing plate 31 (this circularly polarizing plate 110). Although the organic EL display device having the organic functional layer 36 will be described, the present invention 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 in a desired shape on the base material 33. Then, an interlayer insulating film 34 is formed, and then a pixel electrode 35 is formed by sputtering and patterned. Thereafter, the organic functional layer 36 is laminated.

  Next, the circularly polarizing plate 31 (the present circularly polarizing plate 110) is provided on the surface of the base material 33 opposite to the surface on which the thin film transistor 40 is provided.

  When this circularly polarizing plate 110 is used as the circularly polarizing plate 31, the stacking order will be described with reference to an enlarged view of a portion C surrounded by a dotted line in FIG. When the circular polarizing plate 110 is used as the circular polarizing plate 31, the retardation layer 4 in the circular polarizing plate 110 is disposed on the base material 33 side. (C1) in FIG. 9 is an enlarged view in which the first embodiment of the circularly polarizing plate 110 is used as the circularly polarizing plate 31, and (C2) in FIG. 9 shows the second embodiment of the circularly polarizing plate 110. 3 is an enlarged view used as a circularly polarizing plate 31. FIG.

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

Examples of the substrate 33 include a sapphire glass substrate, a quartz glass substrate, a soda glass substrate and a ceramic substrate such as alumina; a metal substrate such as copper; a plastic substrate.
Although not shown, a heat conductive film may be formed on the substrate 33. Examples of the thermally conductive film include a diamond thin film (DLC or the like). When the pixel electrode 35 is of a reflective type, light is emitted in the direction opposite to the base material 33. Therefore, not only a transparent material but also a non-permeable material such as stainless steel can be used. The substrate may be formed as a single substrate, 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 plate-like materials, and may be films.

  For example, a polycrystalline silicon transistor may be used as the thin film transistor 40. The thin film transistor 40 is provided at the end of the pixel electrode 35 and has a size of about 10 to 30 μm. The size of the pixel electrode 35 is about 20 μm × 20 μm to 300 μm × 300 μm.

  A 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 suppressing resistance by being electrically connected to the pixel electrode 35. In general, the wiring electrode includes Al, Al and transition metals (except for Ti), Ti or Those containing any one or more of titanium nitride (TiN) are 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 sputtering or vacuum deposition of an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride, a silicon oxide layer formed by SOG (spin-on-glass), a photoresist, a polyimide. In addition, any film may be used as long as it has insulating properties, such as a coating film of a resin material such as an acrylic resin.

  A rib 41 is formed on the interlayer insulating film 34. The rib 41 is disposed 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 rib 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 including a pixel electrode 35 that is a transparent electrode, an organic functional layer 36 that is a light emission source, and a cathode electrode 37 will be described. Each of the organic functional layers 36 includes at least one hole transport layer and a light emitting layer, and sequentially includes, for example, an electron injection transport layer, a light emitting layer, a hole transport layer, and a hole injection layer.

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. ITO and IZO are particularly preferable. The pixel electrode 35 only needs to have a certain thickness or more that can sufficiently inject holes, and is preferably about 10 to 500 nm.
The pixel electrode 35 can be formed by an evaporation 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 thereof may be used.

As a constituent material of the cathode electrode 37, for example, 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 the electrode, it is preferable to use a two-component or three-component alloy system selected from the exemplified 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 to 20 at%) is preferable.
The cathode electrode 37 is formed by vapor deposition or sputtering. The thickness of the cathode electrode 37 is 0.1 nm or more, preferably 1 to 500 nm or more.

The hole injection layer has a function of facilitating the injection of holes from the pixel electrode 35, and the hole transport layer has a function of transporting holes and a function of blocking electrons. Also called 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 may vary depending on the formation method, but should be about 5 to 100 nm. Is preferred. Various organic compounds can be used for the hole injection layer and the hole transport layer. For the formation of the hole injecting and transporting layer, the light emitting layer and the electron injecting and transporting layer, a vacuum deposition method can be used in that a homogeneous thin film can be formed.

  Examples of the organic functional layer 36 that is a light emission source include those that use light emission (fluorescence) from singlet excitons, those that use light emission (phosphorescence) from triplet excitons, and those from singlet excitons. Including those using luminescence (fluorescence) and those using triplet excitons (phosphorescence), those formed with organic matter, those formed with organic matter and those formed with inorganic matter , A high molecular material, a low molecular material, a high molecular material and a low molecular material, and the like can be used. However, the present invention is not limited thereto, and an organic functional layer 36 using various known materials for EL elements can be used for the 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 vulnerable to humidity. Moisture is absorbed by the desiccant 38 to prevent the organic functional layer 36 from deteriorating.

FIG. 10 is a schematic diagram showing a cross-sectional configuration of another aspect of the EL display device 30. This EL display device 30 has a sealing structure using a thin film sealing film 41, and can obtain emitted light from the opposite surface of the array substrate.
As the thin film sealing film 41, it is preferable to use a DLC film obtained by evaporating DLC (diamond-like carbon) on an electrolytic capacitor film. The DLC film has a characteristic that moisture permeability is extremely poor, and has high moisture-proof performance. Further, a DLC film or the like may be directly deposited on the surface of the cathode electrode 37. Further, the 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, the novel polarizing film (the present polarizing film) according to the present invention and the novel display device (the present liquid crystal display device and the present EL display device) including the present polarizing film are provided.

Finally, a projection type liquid crystal display device using this polarizing film will be described.
FIG. 11 is a schematic view showing a projection type liquid crystal display device using the present polarizing film.
This polarizing film is used as the polarizer 142 and / or the polarizer 143 of the projection type liquid crystal display device.

  A light bundle emitted from a light source (for example, a high-pressure mercury lamp) 111 that is a light emission source first passes through a first lens array 112, a second lens array 113, a polarization conversion element 114, and a superimposing lens 115. The luminance is uniformed and polarized in the cross section of the anti-beam bundle.

  Specifically, the light bundle emitted from the light source 111 is divided into a number of minute light bundles by the first lens array 112 in which minute lenses 112a are formed in a matrix. The second lens array 113 and the superimposing lens 115 are provided so that each of the divided light bundles irradiates the entire three liquid crystal panels 140R, 140G, and 140B that are illumination targets. The liquid crystal panel incident side surface has almost uniform illuminance as a whole.

  The polarization conversion element 114 is configured by a polarization beam splitter array, and is disposed between the second lens array 113 and the superimposing lens 115. As a result, random polarized light from the light source is converted into polarized light having a specific polarization direction in advance, thereby reducing the amount of light loss in the incident side polarizer described later, thereby improving the screen brightness.

  The light whose luminance is uniformed and polarized as described above is sequentially converted into the red channel, the green channel, and the blue channel by the dichroic mirrors 121, 123, and 132 for separation into the three primary colors of RGB via the reflection mirror 122. These are separated and enter the liquid crystal panels 140R, 140G, and 140B, respectively.

  In the liquid crystal panels 140R, 140G, and 140B, a polarizer 142 is disposed on the incident side, and a polarizer 143 is disposed on the exit side. This polarizing film can be used for the polarizer 142 and the polarizer 143.

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

  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 dichroic dye suitable for the corresponding channel.

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

  Electronic paper is displayed by molecules such as optical anisotropy and dye molecule orientation, displayed by particles such as electrophoresis, particle movement, particle rotation, and phase change, and one end of the film moves And the like, those displayed by molecular color development / phase change, those displayed by light absorption of molecules, and those displayed by self-emission by combining electrons and holes. More specifically, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electronic powder fluid, magnetophoretic type, magnetic thermosensitive Formula, electrowetting, light scattering (transparency / translucency change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, leuco dye And color erasing, photochromic, electrochromic, electrodeposition, flexible organic EL, and the like. The electronic paper may be used not only for personal use of text and images but also for advertisement display (signage) or the like. According to this polarizing film, the thickness of the electronic paper can be reduced.

  As a stereoscopic display device, for example, a method of arranging different retardation films alternately like 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, Since patterning is easy by printing, inkjet, photolithography, etc., the manufacturing process of the display device can be shortened, and a retardation film is not required.

  Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “parts” in the examples are% by mass and parts by mass.

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 according to Lub et al. 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 determining the phase transition temperature of the film made of the compound (1-6). The operation is as follows.
A film made of the compound (1-6) is formed on the alignment film formed on the glass substrate, and the phase transition temperature is confirmed by texture observation with a polarizing microscope (BX-51, manufactured by Olympus) while heating. did. The film made of the compound (1-6) is heated to 120 ° C., and when the temperature is lowered, the film transitions to the nematic phase at 112 ° C., the phase transition to the smectic A phase at 110 ° C., and the smectic B phase at 94 ° C. It was confirmed that the phase transition occurred.

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 in the measurement of the phase transition temperature of compound (1-6). Compound (1-7) was heated to 140 ° C., and at the time of cooling, the phase transition to the nematic phase at 133 ° C., the phase transition to the smectic A phase at 118 ° C., and the phase transition to the smectic B phase at 78 ° C. It was confirmed.

重合開始剤；
１−ヒドロキシ−シクロヘキシル−フェニルケトン
（イルガキュア１８４；チバスペシャルティケミカルズ社製） ６部
レベリング剤；ＢＹＫ−３６１Ｎ（ＢＹＫ−Ｃｈｅｍｉｅ社製） １．５部
重合性非液晶化合物；多官能アクリレート（４−５） ５．０部
溶剤；シクロペンタノン ２５０部 Example 1
[Preparation of the present composition]
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain the present composition (a composition for forming a polarizing film).

Polymerizable liquid crystal compound; Compound (1-6) 75 parts
Compound (1-7) 25 parts Dichroic dye; Compound (2-1-1) 2.5 parts D10 dye described in Japanese Patent No. 3687130

A polymerization initiator;
1-hydroxy-cyclohexyl-phenyl ketone (Irgacure 184; manufactured by Ciba Specialty Chemicals) 6 parts Leveling agent; BYK-361N (manufactured by BYK-Chemie) 1.5 parts Polymerizable non-liquid crystal compound; polyfunctional acrylate (4-5) ) 5.0 parts Solvent; 250 parts of cyclopentanone

(Measurement of phase transition temperature)
Similarly to 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 the temperature rises to 140 ° C., at the time of temperature fall, the phase transition to the nematic phase without forming the phase separation state at 109 ° C., the phase transition to the smectic A phase without forming the phase separation state at 98 ° C., and 74 ° C. It was confirmed that the phase transition to the smectic B phase occurred without forming a phase separation state.

[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% by weight aqueous solution (composition for forming an alignment layer) of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) was applied by spin coating, and dried. A film with a thickness of 100 nm was formed. Subsequently, an alignment layer was formed by subjecting the surface of the obtained film to a rubbing treatment, and a polarizing film was prepared. The rubbing process uses a semi-automatic rubbing apparatus (trade name: LQ-008, manufactured by Joyo Engineering Co., Ltd.) and a push-in amount of 0.15 mm using a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Chemical Co., Ltd.). , Under the conditions of 500 rpm and 16.7 mm / s. By such rubbing treatment, a laminate 1 in which an alignment film was formed on a glass substrate was obtained.

2. Formation of Polarizing Film The polarizing film forming composition is applied onto the alignment film of the laminate 1 by spin coating, heated and dried on a 120 ° C. hot plate for 1 minute, and then quickly cooled to room temperature. A coating film was formed on the alignment film. In such a coating film, the liquid crystal state of the polymerizable liquid crystal compound contained was a smectic B phase. Next, using a UV irradiation device (SPOT CURE SP-7; manufactured by USHIO INC.), The coating film is irradiated with ultraviolet rays at an exposure amount of 2000 mJ / cm ² (reference to 313 nm), whereby polymerization contained in the coating film is performed. The liquid crystalline compound was polymerized while maintaining the liquid crystal state, and a polarizing film was prepared from the coating film. The thickness of the polarizing film at this time was 1.6 μm when measured with a laser microscope (OLS3000 manufactured by Olympus Corporation).

3. X-ray diffraction measurement The obtained polarizing film was subjected to an X-ray diffraction measurement using an X-ray diffractometer X'Pert PRO MPD (Spectris Co., Ltd.). Using Cu as a target, X-rays generated under conditions of an X-ray tube current of 40 mA and an X-ray tube voltage of 45 kV are incident from the orientation direction through a fixed diverging slit 1/2 °, and a scanning range 2θ = 4.0 to 40 As a result of scanning and measuring in steps of 2θ = 0.01671 ° in the range of 0.0 °, a sharp Bragg peak with a peak half-value width (FWHM) = about 0.1718 ° was found in the vicinity of 2θ = 20.24 °. Obtained. In addition, the same result was obtained even when incident from a direction parallel to the surface of the polarizing film and perpendicular to the alignment direction. The order period (d) obtained from the peak position is about 4.4 mm, and it was found that a structure reflecting a higher-order smectic phase was formed.

4). Measurement of dichroic ratio (DR) The dichroic ratio was measured as follows.
Using the apparatus which set the folder with a polarizer to the spectrophotometer (Shimadzu Corporation UV-3150) for the absorbance (A ¹ ) in the transmission axis direction and the absorbance (A ² ) in the absorption axis direction at the maximum absorption wavelength. Measured by the double beam method. The folder was provided with a mesh that cuts the light amount by 50% on the reference side. The ratio (A ² / A ¹ ) was calculated from the measured absorbance (A ¹ ) in the transmission axis direction and absorbance (A ² ) in the absorption axis direction to obtain 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 (A ² ) in the absorption axis direction and the dichroic ratio at that wavelength.

5. Measurement of Haze Value In order to confirm the transparency of the polarizer, the haze value was measured using a haze meter (HZ-2; manufactured by Suga Test Instruments Co., Ltd.). The measurement results are shown in Table 1.

  Examples 2 to 8, Reference Example 1, and Comparative Examples 1 and 2 were prepared in the same manner except that the kind and content of the polymerizable non-liquid crystal compound were changed. In Comparative Example 3, a composition was prepared under the condition that no polymerizable non-liquid crystal compound was added. After coating and drying at 120 ° C., the composition was rapidly moved onto a 70 ° C. hot plate, and then subjected to UV exposure to form a polarizing film. Produced. Each measurement result is shown in Table 1.

In Examples 9 to 15, the polarizing film was formed in the same manner as in Example 1 except that the dichroic dye was changed to the following structural formula (2-3-1) and the kind and content of the polymerizable non-liquid crystal compound were changed. Produced. Each measurement result is shown in Table 1.

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

  This polarizing film can be suitably used for a display device (display) application. Therefore, this composition which can manufacture this this polarizing film has a high industrial value.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Photo-alignment film 3 This polarizing film 4 Phase difference layer 100 Polarizer 210 1st roll 210A Core 220 Second roll 220A Core 230 Third roll 230A Core 240 Fourth roll 240A Core 211A, 211B Coating device 212A, 212B Drying furnace 213A Polarized UV irradiation device 213B Light irradiation device 300 Auxiliary roll 10 Liquid crystal display device 11 Antireflection layers 12a, 12b Polarizers 13a, 13b Retardation films 14a, 14b Base material 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 polarizing plate 33 Base material 34 Interlayer insulating film 35 Pixel electrode 36 Light emitting layer 37 Cathode electrode 38 Drying Agent 39 Sealing film 40 Thin film transistor 41 Rib 42 Thin film sealing film 110 Circular polarizing plate 111 Light source 112 First lens array 112a Lens 113 Second lens array 114 Polarization conversion element 115 Superimposing lenses 121, 123, 132 Dichroic mirror 122 Reflection mirrors 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, which 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) Both the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound have a polymerizable group;
(B) The polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing film exhibits a nematic liquid crystal phase and a smectic liquid crystal phase without forming a phase separation state. The composition for forming a polarizing film according to claim 1, wherein the polymerizable liquid crystal compound is a compound represented by the 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 are each independently a 1,4-phenylene group which may have a substituent or cyclohexane-1,4-diyl which may have a substituent. Wherein at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent, a cyclohexane-1,4-diyl group; The constituent —CH ₂ — may be replaced by —O—, —S— or —NR—, wherein R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and Y ¹ and Y ² are independently of one _{another, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCOO-, a single ^{bond, -N = N -, - CR} a = CR b -, - C≡C- or -CR ^a = the .R ^a and ^{R b} represents an N-, independently of one another, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms ^.U-1 representing the ^.U-2 represents a hydrogen atom or a polymerizable group, .W ¹ and ^{W 2} represents a polymerizable group, independently of one another, a single bond, -O -, - S -, - COO- Or represents —OCOO—, V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group. May be replaced by —O—, —S— or —NH—.   The composition for forming a polarizing film according to claim 1 or 2, wherein the polymerizable non-liquid crystal compound is a monofunctional acrylate or a polyfunctional acrylate. 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 )). The composition for forming a polarizing film according to any one of claims 1 to 3, which is COO-).   The polymerizable film-forming composition according to any one of claims 1 to 4, wherein the polymerizable group possessed by the polymerizable liquid crystal compound and the polymerizable group possessed by the polymerizable non-liquid crystal compound are the same.   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. A composition for forming a polarizing film.   The composition for forming a polarizing film according to claim 1, 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. The manufacturing method of the polarizing film which has the process of the following (I), (II), and (III).
(I) The process of apply | coating the composition for polarizing film formation in any one of Claims 1-7 on the base material or the alignment film formed on the base material, removing a solvent, and forming 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) A step of copolymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound in a coating film formed in (II) in which the polymerizable liquid crystal compound is in a smectic liquid crystal phase.   The method for producing a polarizing film according to claim 8, wherein the base material is a transparent base material that has been subjected to an orientation treatment.   In the step (I-1), the step (II) is a heat treatment until the polymerizable liquid crystal compound contained in the coating film formed in the step (I) exhibits a nematic liquid crystal phase, and the step (I-1). 10. The step of cooling the formed coating film in which the polymerizable liquid crystal compound is in a nematic liquid crystal phase state until the polymerizable liquid crystal compound exhibits a smectic liquid crystal phase (I-2). The manufacturing method of the polarizing film of description.   The polarizing film manufactured by the manufacturing method in any one of Claims 8-10.   The polarizing film according to claim 11, which exhibits a Bragg peak in X-ray diffraction measurement.   A display device comprising the polarizing film according to claim 11.

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