JP6983213B2 - Polarizing film forming composition and polarizing film - Google Patents

Description

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

In recent years, there is a strong demand for thinning of liquid crystal display devices, and accordingly, there is a demand for thinner polarizing elements used in the liquid crystal display devices. In order to realize a thinner polarizing element, 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 of only a polymerizable smectic liquid crystal compound, a dichroic dye, a photopolymerization initiator, and an inhibitor. Further, Patent Document 2 discloses a polarizing film composed of only a polymerizable liquid crystal compound, a dichroic dye, a polymerization initiator, an inhibitor, a gelling agent, and a solvent.

Japanese Patent No. 4719156 Japanese Patent Publication No. 2008-547662

However, there has been a demand for further thinning and high transparency of the polarizing film.
An object of the present invention is to provide a polarizing film forming composition capable of producing a thin and highly transparent polarizing film, and a polarizing film formed from the polarizing film forming composition.

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-separated state (these (A) and (B)). Each of the requirements of 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 independent of each other and may have a substituent 1,4-phenylene group or a cyclohexane-1,4-diyl which may have a substituent. Represents a group, provided that ^{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. is -O - - -CH ₂ constituting, - optionally replaced by S- or -NR- .R is .Y ¹ and ^{Y 2} represents an alkyl group or a phenyl group having 1 to 6 carbon atoms, 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−, ^Ra and R ^b independently of each other represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. U ¹ represents a hydrogen atom or a polymerizable group. U ² represents a polymerization. Represents a sex group. W ¹ and W ² represent a single bond, -O-, -S-, -COO- or -OCOO- ^{independently of each other. V 1} and V ² represent a substituent independently of each other. Represents an alcandiyl group having 1 to 20 carbon atoms which may have, and —CH ₂ − constituting the alcandiyl group may be replaced with —O—, —S— or −NH−. )
[3] The composition for forming a polarizing film according to [1] or [2], wherein the polymerizable non-liquid crystal compound is a monofunctional acrylate or a polyfunctional acrylate.
[4] The polymerizable group of the polymerizable liquid crystal compound and the polymerizable group of the polymerizable non-liquid crystal compound are independently acryloyloxy group (CH ₂ = CHCOO−) or methacryloyloxy group (CH ₂ = C (CH 2 = C). CH ₃ ) The composition for forming a polarizing film according to any one of [1] to [3], which is COO-).
[5] The composition for forming a polarizing film according to any one of [1] to [4], wherein the polymerizable group of the polymerizable liquid crystal compound and the polymerizable group of the polymerizable non-liquid crystal compound are the same.
[6] The 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 [1] to [5]. The composition for forming a polarizing film according to any one.
[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 for.
[8] A method for producing a polarizing film, which comprises the following steps (I), (II) and (III).
(I) The composition for forming a polarizing film according to any one of [1] to [7] is applied onto a substrate or an alignment film formed on the substrate, and the solvent is removed to form a coating film. Process to do;
(II) A step of bringing the polymerizable liquid crystal compound contained in the coating film formed in (I) into a smectic liquid crystal phase state;
(III) A step of copolymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound in a coating film in which the polymerizable liquid crystal compound formed in (II) is in a smectic liquid crystal phase state.
[9] The method for producing a polarizing film according to [8], wherein the base material is a transparent base material that has been subjected to an orientation treatment.
[10] The steps (II) include a step (I-1) of heat-treating the polymerizable liquid crystal compound contained in the coating film formed in the step (I) until the polymerizable liquid crystal compound exhibits a nematic liquid crystal phase, and a step (I-). It is a step having a step (I-2) of cooling the coating film in which the polymerizable liquid crystal compound formed in 1) is in a nematic liquid crystal phase state until the polymerizable liquid crystal compound shows a smectic liquid crystal phase [8]. ] Or [9]. The method for producing a polarizing film.
[11] A polarizing film manufactured by the manufacturing method according to any one of [8] to [10].
[12] The polarizing film according to [11], which shows a Bragg peak in an X-ray diffraction measurement.
[13] A display device including the polarizing film according to [11] or [12].

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

It is a schematic diagram which shows the main part of the continuous manufacturing method (Roll to Roll type) of the polarizing film of this invention. It is a schematic diagram which shows the cross-sectional structure of the liquid crystal display apparatus using the polarizing element which contains the polarizing film of this invention. It is a schematic diagram which shows the layer order of the polarizing element which contains 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 polarizing element which contains 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 type) using the polarizing element which contains the polarizing film of this invention. It is sectional drawing of the circular polarizing plate including the polarizing film of this invention. It is a schematic diagram of the continuous manufacturing method of the circular polarizing plate including the polarizing film of this invention. It is a schematic diagram which shows the structure of the EL display device using the circular polarizing plate including the polarizing film of this invention. It is a schematic diagram which shows the layer order of the circular polarizing plate including the polarizing film of this invention provided in the EL display device. It is a schematic diagram which shows the structure of the EL display device using the circular polarizing plate including the polarizing film of this invention. It is a schematic diagram which shows the structure of the projection type liquid crystal display apparatus using the polarizing element which contains the polarizing film of this invention.

<Composition for forming a polarizing film>
The composition for forming a polarizing film of the present invention (hereinafter, referred to as “the present composition” in some cases) comprises a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, a bicolor dye, a polymerization initiator, and a solvent. contains. The polarizing film formed from the present composition by the production method described later (hereinafter, referred to as “main polarizing film” in some cases) is not only suitable for a liquid crystal display device but also a circular polarizing plate suitable for an organic EL display device. (Hereinafter, in some cases, it is referred to as "this circular polarizing plate"). First, the present 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 without forming a phase-separated state in the coating film formed from the composition. It is a liquid crystal compound having a property showing 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 present composition is applied to a glass substrate, and the applied present composition is heat-treated and / or reduced-pressure treated under the condition that the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound do not polymerize to remove the solvent. Subsequently, the coating film formed on the glass substrate is heated, and it is confirmed whether or not the polymerizable liquid crystal compound contained in the coating film exhibits a nematic liquid crystal phase without phase separation. Subsequently, the heated coating film is gradually cooled, and it is confirmed whether or not the polymerizable liquid crystal compound contained in the coating film 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. The formation of phase separation can be confirmed, for example, by observing the surface with various microscopes or measuring 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 high-order smectic phase referred to here is the smectic B phase, the smectic D phase, the smectic E phase, the smectic F phase, the smectic G phase, the smectic H phase, the smectic I phase, the smectic J phase, the smectic K phase and the smectic L phase. Yes, among others, smectic B phase, smectic F phase and smectic I phase are more preferable. When the smectic liquid crystal phase exhibited by the polymerizable liquid crystal compound is these higher-order smectic phases, a present polarizing film having a higher degree of orientation order can be produced. Further, in this polarizing film having a high degree of orientation order, a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase can be obtained in an X-ray diffraction measurement.

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

Preferred polymerizable liquid crystal compounds include, for example, a compound represented by the formula (1) (hereinafter, sometimes referred to as “compound (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 equation (1),
X ¹ , X ² and X ³ represent a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent independently of each other. 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 with -O-, -S- or -NR-. R represents an alkyl group or a phenyl group having 1 to 6 carbon atoms.
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 -, - Represents C≡C− or −CR ^a = N−. R ^a and R ^b 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 independently represent a single bond, -O-, -S-, -COO- or -OCOO-.
V ¹ and V ² represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent independently of each other, and −CH ₂ − constituting the alkanediyl group is −O−, −. It may be replaced with S- or -NH-. ]

In 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. The trans-cyclohexane-1,4-diyl group which may have the above is preferably unsubstituted.

The substituents optionally possessed by the 1,4-phenylene group which may have a substituent or the cyclohexane-1,4-diyl group which may have a substituent include a methyl group, an ethyl group and a substituent. Examples thereof include an alkyl group having 1 to 4 carbon atoms such as a butyl group; a cyano group; a halogen atom and the like.

^{Y 1} of 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, preferably a polymerizable group. Both U ¹ and U ² are preferably polymerizable groups, and both are preferably photopolymerizable groups. Here, the photopolymerizable group means 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 lower temperature conditions. As the photopolymerizable group, a radically polymerizable group is preferable. The radically polymerizable group means a group that can participate in a polymerization reaction by an active radical generated from a polymerization initiator described later.

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

The ^{alkanediyl groups of V 1} and V ² include 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 icosan -1,20-diyl group and the like can be mentioned. V ¹ and V ² are preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.
Examples of the substituent arbitrarily possessed by the alkanediyl group having 1 to 20 carbon atoms which may have a substituent include a cyano group and a halogen atom, and the alkanediyl group may be unsubstituted. It is preferably an unsubstituted and linear alkanediyl group, more preferably.

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

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

The polymerizable liquid crystal compound can be used alone or in combination of two or more in the present composition.
When two or more kinds are mixed, it is preferable that at least one kind is compound (1), and it is more preferable that two or more kinds are compound (1). When two kinds of polymerizable liquid crystal compounds are mixed, the mixing ratio is usually 1:99 to 50:50, preferably 5:95 to 50:50, and more preferably 10:90 to 50:50. Is.

The polymerization temperature of the present composition is usually equal to or lower than the smectic phase transition temperature of the polymerizable liquid crystal compound. The polymerization temperature of the present composition can be controlled by adjusting the components contained in the present composition. It is preferable to determine 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 polymerizes under temperature conditions lower than the phase transition temperature. When the present composition contains two or more kinds of polymerizable liquid crystal compounds, the smectic phase transition temperature of the mixture of the two or more kinds of polymerizable liquid crystal compounds is obtained and controlled in the same manner.

Among the exemplified compounds (1), the formulas (1-2), formulas (1-3), formulas (1-4), formulas (1-6), formulas (1-7), and formulas (1-8) , Formulas (1-13), formulas (1-14) and compounds represented by formulas (1-15) are preferred. These compounds easily maintained the liquid crystal state of the higher-order smectic phase under temperature conditions below the smectic phase transition temperature by interacting with other polymerizable liquid crystal compounds or polymerizable non-liquid crystal compounds. Up to that, it can be polymerized.

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

The polymerizable liquid crystal compound is, for example, Lubet 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 coloring (absorption into visible light) by itself, (ii) compatibility to the extent that it is uniformly mixed with the polymerizable liquid crystal compound, and (iii) polymerizable. It is preferable not to inhibit the formation of the liquid crystal state indicated by the liquid crystal compound.

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. Polyfunctional acrylates are preferable because 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.

It is preferable that the polymerizable group of the polymerizable non-liquid crystal compound is the same as the polymerizable group of the polymerizable liquid crystal compound.
When at least one compound selected from the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound has a plurality of types of polymerizable groups, the polymerizable liquid crystal compound has at least one polymerizable group and the polymerizable non-liquid crystal compound. It is preferable that the product has at least one polymerizable group.

A more suitable polymerizable non-liquid crystal compound has the characteristics of (i), (ii) and (iii) above, and has 1 to 6, preferably 2 to 6 polymerizable groups in the molecule. Examples thereof include monofunctional acrylates and polyfunctional acrylates. Since the monofunctional acrylate and the polyfunctional acrylate are non-liquid crystal, those having no mesogen structure are preferable.
Further, the polymerizable liquid crystal compound contained in the coating film obtained from the present composition has a urethane structure, an amino structure, an epoxy structure, an ethylene glycol structure and a polyester structure in the molecule as long as the nematic liquid crystal phase and the smectic liquid crystal phase are not disturbed. It may be included.

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

The monofunctional acrylate is a group selected from the group consisting of an acryloyloxy group (CH ₂ = CH-COO-) and a methacryloyloxy group (CH ₂ = C (CH ₃ ) -COO-) (hereinafter, (meth) acryloyloxy). It is a compound having one (sometimes referred to as a group) in the molecule. When the polymerizable non-liquid crystal compound is a monofunctional acrylate, it is preferable that the polymerizable liquid crystal compound also has a (meth) acryloyloxy group.

Examples of the monofunctional acrylate having one (meth) acryloyloxy group include alkyl (meth) acrylates having 4 to 16 carbon atoms, βcarboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylation having 2 to 14 carbon atoms. Examples thereof include phenyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate and isobonyl (meth) acrylate.

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

Bifunctional acrylates having two (meth) acryloyloxy groups include 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate. Ethylene glycol di (meth) acrylate; Diethylene glycol di (meth) acrylate; Neopentyl glycol di (meth) acrylate; Triethylene glycol di (meth) acrylate; Tetraethylene glycol di (meth) acrylate; Polyethylene glycol diacrylate; Bisphenol A Bis (acryloyloxyethyl) ether; ethoxylated bisphenol A di (meth) acrylate; propoxylated neopentyl glycol di (meth) acrylate; ethoxylated neopentyl glycol di (meth) acrylate and 3-methylpentanediol di (meth). ) Acrylate and the like are exemplified.

As a polyfunctional acrylate having 3 to 6 (meth) acryloyloxy groups,
Trimethylol propanetri (meth) acrylate; pentaerythritol tri (meth) acrylate; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; ethoxylated trimethylol propanetri (meth) acrylate; propoxylated trimethylol propanetri (meth) acrylate Meta) acrylate; pentaerythritol tetra (meth) acrylate; dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate; tripentaerythritol tetra (meth) acrylate; tripentaerythritol penta (meth) acrylate; tripenta Elythritol hexa (meth) acrylate; tripentaerythritol hepta (meth) acrylate; tripentaerythritol octa (meth) acrylate;
Pentaerythritol tri (meth) acrylate and acid anhydride reaction product; dipentaerythritol penta (meth) acrylate and acid anhydride reaction product;
A reaction product of tripentaerythritol hepta (meth) acrylate and acid anhydride;
Caprolactone-modified trimethylol propantri (meth) acrylate; caprolactone-modified pentaerythritol tri (meth) acrylate; caprolactone-modified tris (2-hydroxyethyl) isocyanuratetri (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. ) Acrylate; Caprolactone-modified tripentaerythritol hepta (meth) acrylate; Caprolactone-modified tripentaerythritol octa (meth) acrylate; Caprolactone-modified pentaerythritol tri (meth) acrylate and acid anhydride reaction product; Caprolactone-modified dipentaerythritol penta ( Examples thereof include a reaction product of a meta) acrylate and an acid anhydride, and a caprolactone-modified tripentaerythritol hepta (meth) acrylate and an acid anhydride. In the specific example of the polyfunctional acrylate shown here, (meth) acrylate means acrylate or methacrylate. Further, caprolactone denaturation means that a ring-opening compound or a ring-opening polymer of caprolactone is introduced between the alcohol-derived moiety of the (meth) acrylate compound and the (meth) acryloyloxy group.

Commercially available products can also be used for such polyfunctional acrylates.
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 "",Same" M-360 ", same" M-305 ", same as" M-306 ", same as" M-450 ", same as" M-451 ", same as" M-408 ", same as" M-400 " , Same "M-402", same "M-403", same "M-404", same "M-405", same "M-406" (manufactured by Toa Synthetic Co., Ltd.), "EBECRYL11", same "145"",Same" 150 ", Same" 40 ", Same" 140 ", Same" 180 ", DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA, TMPTA, TMPEOTA, DPHA, EBECRYL series (manufactured by Daisel Cytec Co., Ltd.) And so on.

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

The content of the polymerizable non-liquid crystal compound in the present composition is usually 0.1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 3 with respect to the total mass of the present composition. ~ 7% by mass. It is more preferably 0.1 to 19 parts by mass, still more preferably 1 to 15 parts by mass, and particularly preferably 4 to 10 parts by mass with respect to 100 parts by mass of the solid content of the present composition. Further, it is particularly preferable that the amount is 3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by weight of the polymerizable liquid crystal compound. When the content of the polymerizable non-liquid crystal compound is within the above range, the polymerizable component (polymerizable) in the present composition is not disturbed without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the present composition. A liquid crystal compound and a polymerizable non-liquid crystal compound) can be copolymerized, which is preferable. Although it depends on the types 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 pigment>
The dichroic dye refers to a dye having a property in which the absorbance in the major axis direction and the absorbance in the minor axis direction of the molecule are different. 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 kinds of compounds.

The dichroic dye preferably has a maximum absorption wavelength (λMAX) in the range of 300 to 700 nm. Examples of such a dichroic dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye and an anthraquinone dye, and among them, the azo dye is preferable. Examples of the azo dye include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes and stilbene azo dyes, and bisazo dyes and trisazo dyes are preferable.

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 equation (2),
A ¹ and A ³ are independent of each other, 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 is a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocycle which may have a substituent. Represents a group. p represents an integer of 1 to 4. When p is an integer of 2 or more, the plurality of A ^2s may be the same or different from each other. ]

Examples of the monovalent heterocyclic group include a group obtained by removing one hydrogen atom 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 such a heterocyclic compound are as described above.

Phenyl group in A ¹ and A ^3, a naphthyl group and a monovalent heterocyclic group, and p- phenylene group in A ^2, the substituent naphthalene-1,4-diyl group and divalent heterocyclic group has optionally 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; an alkyl fluoride group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; Nitro group; Halogen atom; Substituent 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 It means an amino group in which substituted alkyl groups are bonded to each other to form an alcandiyl group having 2 to 8 carbon atoms. The unsubstituted amino group is -NH ₂ ). Specific examples of the alkyl group having 1 to 6 carbon atoms are the same as those exemplified for the substituent arbitrarily possessed by the phenylene group and the like of the compound (1).

Among the compounds (2), the 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 equations (2-1) to (2-6),
B ^{1 to} B ²⁰ are independent of each other, 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, and a substituted or unsubstituted amino group (substituted amino group and The definition of an unsubstituted amino group is as described above), and represents a chlorine atom or a trifluoromethyl group.
n1 to n4 represent integers 0 to 3 independently of each other.
If n1 is 2 or more, a plurality of B ² may be the same or different from each other,
If n2 is 2 or more, plural B ⁶ may be the same or different from each other,
If n3 is 2 or more, plural B ⁹ may be the same or different from each other,
When n4 is 2 or more, the plurality of B ^14s may be the same 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 the anthraquinone dye, a compound represented by the formula (2-7) is preferable.

[In equation (2-7),
R ^{1 to} R ⁸ 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 equation (2-8),
R ^{9 to} R ¹⁵ represent hydrogen atoms, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or halogen atoms independently of each other.
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 equation (2-9),
R ^{16 to} R ²³ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

^{The alkyl group having 1 to 4 carbon atoms represented by Rx} in the formula (2-7), the formula (2-8) and the formula (2-9) includes a methyl group, an ethyl group, a propyl group and a butyl group. , Pentyl group, hexyl group and the like, and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xsilyl 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 equation (2-10),
D ¹ and D ² represent groups represented by any of the formulas (2-10a) to (2-10d) independently of each other.

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 equation (2-11),
D ³ and D ⁴ represent groups represented by any of the formulas (2-11a) to (2-11h) independently of each other.

n6 represents an integer of 1 to 3. ]

The content of the bicolor dye in the present composition is preferably 0.1 part by mass or more and 30 parts by mass or less, and 0.1 part by mass or more and 20 parts by mass or less, with respect to 100 parts by mass of the content of the polymerizable liquid crystal compound. Is more preferable, 0.1 parts by mass or more and 10 parts by mass or less is further preferable, and 0.1 parts by mass or more and 5 parts by mass or less is particularly preferable. When the content of the dichroic dye is within this range, the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be used 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. If the content of the dichroic dye is too large, the orientation of the polymerizable liquid crystal compound may be hindered. Therefore, the content of the dichroic dye can be determined as long as the polymerizable liquid crystal compound can maintain the liquid crystal state.

As the dichroic dye, a commercially available one 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 active radicals by the action of light is preferable.

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

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

Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenylsulfide, and 3,3', 4,4'-tetra (tert-butylperoxycarbonyl). ) Benzophenone and 2,4,6-trimethylbenzophenone and the like.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) Butane-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] propane-1-one, 1-hydroxycyclohexylphenylketone and 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1- Examples include 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 and 2,4-bis (trichloromethyl) -6- (4-methoxy). Naftil) -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- (fran-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) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine and the like can be mentioned.

Commercially available polymerization initiators can be used. Commercially available polymerization initiators include "Irgacure 907", "Irgacure 184", "Irgacure 651", "Irgacure 819", "Irgacure 250", "Irgacure 369" (Ciba Japan Co., Ltd.); " "Sakeall BZ", "Sakeall Z", "Sakeall BEE" (Seiko Kagaku Co., Ltd.); "Kayacure BP100" (Nippon Kayaku Co., Ltd.); "Kayacure UVI-6992" (Dow); " ADEKA PTOMER SP-152 "," ADEKA PTOMER SP-170 "(ADEKA Corporation);" TAZ-A "," TAZ-PP "(Nippon Sibel Hegner); and" TAZ-104 "(Sanwa Chemical Co., Ltd.) Company) and so on.

The content of the polymerization initiator in the present composition can be appropriately adjusted according to the type of the polymerizable liquid crystal compound and the amount thereof, but is usually 0.1 to 1 with respect to 100 parts by mass of the content of the polymerizable liquid crystal compound. It is 30 parts by mass. It is preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass. When the content of the polymerization initiator is within this range, the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be coexisted without disturbing the orientation of the polymerizable liquid crystal compound contained in the coating film obtained from the present composition. It is preferable because it can be polymerized.

<Solvent>
The present composition contains a solvent. As the solvent, a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound, and a solvent capable of completely dissolving the dichroic dye are preferable. Further, it is preferable that the solvent is inert to the polymerization reaction in the present composition.
Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate and 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; ether solvents such as tetrahydrofuran and dimethoxyethane; and chlorine-containing solvents such as chloroform and chlorobenzene; and the like. These solvents may be used alone or in combination of two or more.

The content of the solvent is preferably 50 to 98% by mass with respect to the total amount of the present composition. In other words, the solid content in the present composition is preferably 2 to 50% by mass. When the solid content is 2% by mass or more, the present polarizing film tends to be easily obtained, which is preferable. 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 present polarizing film becomes substantially uniform, and the present polarizing film tends to be less likely to have unevenness. preferable. Further, the solid content can be determined in consideration of the thickness of the present polarizing film to be manufactured.

The present composition may contain a component other than the above-mentioned components, and examples of such a component include a polymerization reaction aid that controls a polymerization reaction such as a polymerizable liquid crystal compound.

<Polymerization reaction aid>
The 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 (eg, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene and anthracene such as alkoxy group-containing anthracene (eg, dibutoxyanthracene, etc.). Compounds; examples include phenothiazine and rubrene.

When the present composition contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound contained in the present composition can be further promoted. 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 100 parts by mass of the total of the polymerizable liquid crystal compound. Is more preferable.

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

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

When the present composition contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.1 to 30 parts by mass, preferably 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 to 8 parts by mass is further preferable. When the content of the polymerization inhibitor is within this range, the polymerizable liquid crystal compound contained in the polarizing film forming composition can be polymerized without disturbing the orientation, so that the polymerizable liquid crystal compound is more suitable. Further, polymerization can be carried out 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 present composition and flattening the coating film obtained by applying the present composition, and examples thereof include a surfactant. The leveling agent is more preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component. The polyacrylate compound referred to here does not have a polymerizable group.

Examples of the leveling agent containing a polyacrylate compound as a main component include "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-358N", and ". BYK-361N "," BYK-380 "," BYK-381 "and" BYK-392 "[BYK Chemie] and the like can be mentioned.

Examples of the leveling agent containing a fluorine atom-containing compound as a main component include "Megafuck R-08", "R-30", "R-90", "F-410", and "F-411". Same as "F-443", same as "F-445", same as "F-470", same as "F-471", same as "F-477", same as "F-479", same as "F-482" and same "F-483" [DIC Co., Ltd.]; "Surflon S-381", the same "S-382", the same "S-383", the same "S-393", the same "SC-101", the same "SC" -105 "," KH-40 "and" SA-100 "[AGC Seimi Chemical Co., Ltd.];" E1830 "," E5844 "[Daikin Fine Chemical Laboratory Co., Ltd.];" Ftop EF301 ", the same" EF303 ", The same" EF351 "and the same" EF352 "[Mitsubishi Material Denshi Kasei Co., Ltd.] and the like.

When the leveling agent is contained in the present composition, the content thereof 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. When the content of the leveling agent is within the above range, it is easy to horizontally orient the polymerizable liquid crystal compound, and the obtained polarizing film tends to be smoother, which is preferable. 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. The present composition may contain two or more types of leveling agents.

<Method of forming this polarizing film>
Next, a method for forming the present polarizing film from the present composition will be described. First, the present composition is applied onto a substrate or an alignment film formed on the substrate. It is preferably applied onto an alignment film formed on a substrate. A transparent base material is preferable as the base material.

<Transparent substrate>
The transparent base material is a base material having transparency enough to transmit light, particularly visible light. The transparency means a characteristic that the transmittance for light rays having a wavelength of 380 to 780 nm is 80% or more. Specific examples of such a transparent base material include a glass base material and a plastic base material. Examples of the plastic constituting the plastic base material include polyolefins such as polyethylene, polypropylene, and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohols; polyethylene terephthalates; polymethacrylic acid esters; polyacrylic acid esters; triacetyl cellulose, Cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; plastics such as polyphenylene sulfide and polyphenylene oxide can be mentioned. Among them, cellulose ester, cyclic olefin resin, polycarbonate, polyethylene terephthalate or polymethacrylic acid ester are particularly preferable because they are easily available on the market and have excellent transparency. In manufacturing the present polarizing film using such a transparent base material, the transparent base material can be easily handled without causing damage such as tearing when the transparent base material is transported or stored. A supporting base material or the like may be attached. Further, as will be described later, when a circularly polarizing plate is manufactured from the present polarizing film, a phase difference property may be imparted to the plastic base material. In this case, the plastic base material may be stretched to impart retardation. The method of imparting retardation to the transparent substrate will be described later.

Cellulose ester is one in which at least a part of the hydroxyl groups contained in cellulose is esterified with acetic acid. Cellulose ester films made of such cellulose esters are readily available on 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 needed. Further, the surface of the prepared transparent base material can be used as a transparent base material after being subjected to surface treatment such as antiglare treatment, hard coat treatment, antistatic treatment or antireflection treatment.

The cyclic olefin resin is composed of, for example, a polymer or copolymer (cyclic olefin resin) of a cyclic olefin such as norbornene or a polycyclic norbornene monomer, and the cyclic olefin resin is partially used. It may include a ring-opening portion. Further, a cyclic olefin resin containing a ring-opening portion may be hydrogenated. Further, the cyclic olefin resin is a copolymer of, for example, a cyclic olefin and a chain olefin or a vinylized aromatic compound (styrene, etc.) in that the transparency is not significantly impaired and the hygroscopicity is not significantly increased. May be. Further, the cyclic olefin resin may have a polar group introduced into 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 is also a vinylized 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 50 mol% or less, for example, about 15 to 50 mol% with respect to the total structural unit of the cyclic olefin resin. When the cyclic olefin resin is a ternary copolymer obtained from a cyclic olefin, a chain olefin, and a vinylized aromatic compound, for example, the content ratio of the structural unit derived from the chain olefin is the cyclic olefin. It is about 5 to 80 mol% with respect to the total structural unit of the system resin, and the content ratio of the structural unit derived from the vinylized aromatic compound is about 5 to 80 mol%. The cyclic olefin resin of such a ternary copolymer has an advantage that the amount of expensive cyclic olefin used can be relatively reduced when the cyclic olefin resin is produced.

Cyclic olefin resins are readily available on the market. Commercially available cyclic olefin resins include "Topas" [Ticona (Germany)]; "Arton" [JSR Corporation]; "ZEONOR" and "ZEONEX" [Zeon Corporation]. ; "Apel" [manufactured by Mitsui Chemicals, Inc.] and the like. Such a cyclic olefin resin can be formed into a film (cyclic olefin resin film) by a known film forming means such as a solvent casting method or a melt extrusion method. Further, a cyclic olefin resin film already commercially available in the form of a film can also be used. Examples of such commercially available cyclic olefin resin films include "Scina" and "SCA40" [Sekisui Chemical Co., Ltd.]; "Zeonoa Film" [Optes Co., Ltd.]; "Arton Film" [JSR Corporation. ] And so on.

Subsequently, a method of imparting retardation to the plastic base material will be briefly described. The plastic base material can be imparted with a retardation property by a known stretching method. For example, a roll (winding body) in which a plastic base material is wound on a roll is prepared, the plastic base material is continuously unwound from the winding body, and the unwound plastic base material is transferred to a heating furnace. And transport. The set temperature of the heating furnace is in the range from near the glass transition temperature (° C) to [glass transition temperature +100] (° C) of the plastic substrate, preferably near the glass transition temperature (° C) to [glass transition temperature +50] (° C). ). In the heating furnace, when the plastic base material is stretched in the traveling direction or in the direction orthogonal to the traveling direction, the transport direction and tension are adjusted to incline at an arbitrary angle for uniaxial or biaxial thermal stretching treatment. I do. The stretching 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. Further, the method of stretching in the oblique direction is not particularly limited as long as the orientation axis can be continuously tilted to a desired angle, and a known stretching method can be adopted. Examples of such a stretching method include the methods described in JP-A No. 50-83482 and JP-A-2-113920.

The thickness of the transparent base material is preferably thin in that it is heavy enough to be handled practically and that sufficient transparency can be ensured, but if it is too thin, the strength is lowered and the processability is inferior. Tend. The appropriate thickness of the glass substrate is, for example, about 100 to 3000 μm, preferably 100 to 1000 μm. The appropriate thickness of the plastic substrate is, for example, about 5 to 300 μm, preferably 20 to 200 μm. When this polarizing film is used as a circularly polarizing plate to be described later, it is preferable that the thickness of the transparent substrate is thinner when it is used as a circularly polarizing plate for mobile devices, and the thickness of a glass substrate is 100 to 500 μm. The thickness is preferably about 20 to 100 μm in the case of a plastic base material. When imparting retardation to the plastic substrate by stretching, the thickness after stretching is determined by the thickness before stretching and the stretching ratio.

<Alignment film>
It is preferable that an alignment film is formed on the base material used for producing the present polarizing film. In that case, the present composition will be applied on the alignment film. Therefore, it is preferable that the alignment film has solvent resistance to the extent that it does not dissolve when the composition is applied. Further, it is preferable to have heat resistance in heat treatment for removing a solvent and orienting a liquid crystal display. The alignment film can be formed by using an orientation polymer.

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

The oriented polymer can form an oriented film on the substrate by applying the oriented polymer as an oriented polymer composition (solution containing the oriented polymer) dissolved in a solvent onto the substrate. Examples of the solvent include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; 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, methylamylketone and methylisobutylketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; toluene and Examples include aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-substituted hydrocarbon solvents such as chloroform and chlorobenzene; and the like. These organic solvents may be used alone or in combination of two or more.

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

As a method of forming an alignment film on the base material, for example, the orientation polymer composition or a commercially available alignment film material is applied onto the base material, and then annealed to align the alignment film on the base material. 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, preferably in the range of 10 nm to 1000 nm.

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

As a method of applying an orientation regulating force by the rubbing method, for example, a rubbing cloth is wound around the rubbing roll, a rotating rubbing roll is prepared, and a laminate in which a coating film for forming an alignment film is formed on a base material is staged. A method of bringing the alignment film forming coating film into contact with the rotating rubbing roll by placing the film on the surface and transporting the film toward the rotating rubbing roll can be mentioned.

Further, a so-called photoalignment 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 "composition for forming a photo-alignment layer") onto a substrate. A alignment film in which a photo-alignment-inducing layer is formed on a substrate and an orientation-regulating force is applied to the photo-alignment-inducing layer by irradiating it with polarized light (preferably polarized UV) to form the photo-alignment layer. A photoreactive group is a group that produces a liquid crystal alignment ability by irradiating with light (light irradiation). Specifically, it causes a photoreaction that is the origin of the liquid crystal alignment ability, such as a molecule orientation-inducing or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction, which is caused by irradiation with light. be. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable in that they have excellent orientation and maintain a smectic liquid crystal state at the time of forming a polarizing film. As the photoreactive group capable of causing the above reaction, an unsaturated bond, particularly a double bond is preferable, and a carbon-carbon double bond (C = C bond) and a carbon-nitrogen double bond (C) are preferable. A group having at least one selected from the group consisting of (= N bond), nitrogen-nitrogen double bond (N = N bond), and 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 stillvazol group, a stillvazolium group, a chalcone group and a cinnamoyl group. Examples of the photoreactive group having a C = N bond include a group 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 an azoxylbenzene as a basic structure. Examples of the photoreactive group having a C = O bond include a benzophenone group, a coumarin group, an anthraquinone group, a maleimide group and the like. These groups may have a substituent such as an alkyl group, an alkoxy group, an allyl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group and an alkyl halide group.
Among them, a photoreactive group capable of causing a photodimerization reaction is preferable, and a photo-alignment layer in which a cinnamoyl group and a chalcone group require a relatively small amount of polarized light for photo-orientation and are excellent in thermal stability and temporal stability is obtained. It is preferable because it is easy to obtain. Furthermore, as the polymer having a photoreactive group, a polymer having a cinnamoyl group having a cinnamic acid structure at the end of the side chain of the polymer is particularly preferable.

The solvent of the composition for forming a photo-alignment layer is preferably one that dissolves a polymer and a monomer having a photoreactive group, and examples of the solvent include the solvent used in the above-mentioned orientation 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 a photoreactive group and the thickness of the photoalignment film to be produced. In terms of solid content concentration, it is preferably at least 0.2% by mass, and particularly preferably in the range of 0.3 to 10% by mass. Further, the composition may contain a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer as long as the characteristics of the photoalignment film are not significantly impaired.

As a method of applying the composition for forming a photo-alignment layer on a substrate, a coating method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method and an applicator method, or a flexographic method is used. A known method such as a printing method such as is adopted. When the present polarizing film is manufactured by the Roll to Roll type continuous manufacturing method described later, a printing method such as a gravure coating method, a die coating method or a flexographic method is usually adopted as the coating method.

If masking is performed during rubbing or polarized light irradiation, it is possible to form a plurality of regions (patterns) having different orientation directions.

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

Next, the coating film is formed by removing the solvent under the condition that the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound contained in the coating film do not polymerize. Examples of the 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 is in a state of exhibiting a smectic liquid crystal phase. In this case, it is preferable to utilize the characteristics of the polymerizable liquid crystal compound to change the liquid crystal state to the nematic liquid crystal phase and then transfer the nematic liquid crystal phase to the smectic liquid crystal phase. In order to transfer the liquid crystal phase in this way, first, the polymerizable liquid crystal compound contained in the coating film is heated to a temperature higher than the temperature showing the nematic liquid crystal phase, and then cooled to the temperature at which the polymerizable liquid crystal compound shows the 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 the smectic liquid crystal phase or the nematic liquid crystal phase may be determined in advance by observing the texture using the present composition or the like.

When the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound are polymerized, the polymerizable liquid crystal compound contains two or more kinds of polymerizable liquid crystal compounds as the polymerizable liquid crystal compound in order to maintain the smectic liquid crystal phase well. 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, a smectic liquid crystal phase is formed via the nematic liquid crystal phase, and then the temperature that originally shows the crystalline phase is temporarily excessive. It is possible to form a cooled state, and there is an advantage that the liquid crystal state of the higher-order smectic phase can be easily maintained. When the two types of polymerizable liquid crystal compounds are contained, the content ratio of the two types of polymerizable liquid crystal compounds is usually 1:99 to 50:50, preferably 5:95 to 50:50, and more. It is preferably 10:90 to 50:50.

Next, the polymerization process of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound will be described.
After the polymerizable liquid crystal compound in the coating film is made 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 with energy under conditions under which the polymerization initiator is activated, and light is mentioned as a preferable energy. The light to be irradiated includes the type of the polymerization initiator contained in the coating film, the type of the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound (particularly, the type of the polymerizable group of the polymerizable liquid crystal compound) and the amount thereof. Depending on the situation, it can be carried out by light or an active electron beam selected from the group consisting of visible light, ultraviolet light and laser light. Of these, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and it is possible to use an apparatus widely used in the art as an apparatus related to polymerization. Therefore, it is preferable to select the types of the polymerizable liquid crystal compound, the polymerizable non-liquid crystal compound, and the polymerization initiator contained in the present composition so that the polymer can be polymerized by ultraviolet light. Further, at the time of polymerization, the polymerization temperature can be controlled by cooling the coating film by an appropriate cooling means together with ultraviolet light irradiation. If the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound can be polymerized at a lower temperature by adopting such a cooling means, even if the above-mentioned base material has a relatively low heat resistance, the present polarization is appropriately performed. It also has the advantage of being able to form a film. It should be noted that a patterned main polarizing film can also be obtained by masking or developing at the time of polymerization.

By performing the above-mentioned polymerization, the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of the smectic phase, preferably the higher-order smectic phase as already exemplified, and the present polarizing film is formed. This polarizing film obtained by polymerizing a polymerizable liquid crystal compound while maintaining the liquid crystal state of the smectic phase is a conventional host-guest type polarizing film, that is, the liquid crystal state of the nematic phase due to the action of the dichroic dye. There is an advantage that the polarizing performance is higher than that of a polarizing film obtained by polymerizing a polymerizable liquid crystal compound or the like while retaining the above. Further, there is an advantage that the strength is excellent as compared with the one coated only with the dichroic dye or the lyotropic liquid crystal.

The thickness of the present polarizing film thus formed is preferably in the range of 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less. Therefore, the thickness of the coating film for forming the main polarizing film is determined in consideration of the thickness of the obtained main polarizing film. The thickness of the polarizing film is determined by measurement with an interference film thickness meter, a laser microscope, or a stylus type film thickness meter.

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

Further, as described above, it is particularly preferable that the present polarizing film thus formed can obtain a Bragg peak in the X-ray diffraction measurement. Examples of the main polarizing film from which such a Bragg peak can be obtained include a main polarizing film showing a diffraction peak derived from a hexatic phase or a crystal phase.

<Continuous manufacturing method of this polarizing film>
The outline of the method for producing the present polarizing film has been described above, but when the present polarizing film is commercially produced, a method capable of continuously producing the present polarizing film is 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 this manufacturing method, the case where the base material is a transparent base material will be mainly described.

This manufacturing method is, for example,
The process of preparing the first roll in which the transparent substrate is wound around the first core, and
A step of continuously feeding out the transparent base material from the first roll,
A step of continuously applying the composition for forming a photoalignment layer to a transparent substrate, and
A step of removing the solvent from the coated composition for forming a photo-alignment layer to continuously form a first coating film on a transparent substrate.
A step of continuously forming a photo-alignment layer and forming a photo-alignment film by irradiating the coating film with polarized UV.
A step of continuously applying the present composition onto the photoalignment film, and
A step of continuously forming a second coating film on the photoalignment film by drying the coated composition under conditions where the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound do not polymerize.
A step of continuously obtaining a polarizing film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal phase after changing the liquid crystal state of the polymerizable liquid crystal compound contained in the coating film to a smectic liquid crystal phase.
The present invention comprises a step of winding a continuously obtained laminate containing a transparent substrate, a photoalignment film, and a polarizing film onto a second winding core to obtain a second roll. Here, the present manufacturing method will be described with reference to FIG.

The first roll 210, in which the transparent substrate is wound around the first core 210A, is readily available on the market, for example. Examples of the transparent base material available on the market in the form of such a roll include a film made of a cellulose ester, a cyclic olefin resin, a polycarbonate, a polyethylene terephthalate, or a polymethacrylic acid ester, among the transparent base materials already exemplified. .. Further, when this polarizing film is used as a circular polarizing plate, a transparent base material to which a retardation property is imparted in advance can be easily obtained from the market, for example, a retardation film made of a cellulose ester, a polycarbonate or a cyclic olefin resin. Can be mentioned.

Subsequently, the transparent base material is sent out from the first roll 210. The method of feeding out the transparent base material is performed by installing an appropriate rotating means on the winding core 210A of the first roll 210 and rotating the first roll 210 by the rotating means. Further, an appropriate auxiliary roll 300 may be installed in the direction of sending out the transparent base material from the first roll 210, and the transparent base material may be sent out by the rotating means of the auxiliary roll 300. Further, by installing a rotating means for both the first winding core 210A and the auxiliary roll 300, the transparent base material may be sent 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 device 211A, the composition for forming a photo-alignment layer is coated on the surface of the transparent substrate by the coating device 211A. The coating device 211A for continuously coating the composition for forming a photoalignment layer in this way is usually a printing device capable of coating by a gravure coating method, a die coating method, a flexographic method, or the like.

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

The first coating film continuously formed by passing through the heating furnace 212A is subsequently irradiated with polarized UV on the surface of the first coating film or the surface on the transparent substrate side by the polarized UV irradiation device 213A. It forms a photo-alignment layer and forms a photo-alignment film.

The laminated body of the base material and the photoalignment film thus continuously formed passes through the coating device 211B to apply the present composition on the photoalignment film and then passes through the drying furnace 212B. As a result, the polymerizable liquid crystal compound contained in the present 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 coated on the photoalignment film, and the present composition so that the polymerizable liquid crystal compound contained in the composition shows a smectic liquid crystal phase via a nematic liquid crystal phase. It plays the role of giving heat energy to things. The drying oven 212B may be capable of performing a multi-step heat treatment in order to form a nematic liquid crystal phase and then a smectic liquid crystal phase of the polymerizable liquid crystal compound. That is, the drying furnace 212B may be divided into a plurality of zones and the set temperature may be different for each of the divided plurality of zones, similar to the drying furnace 212A, and the plurality of drying furnaces are arranged in series. It may be a type of drying oven in which the set temperature is different for each drying oven.

In the film that has passed through the drying furnace 212B, the solvent contained in the present composition is sufficiently removed, and the polymerizable liquid crystal compound in the second coating film is conveyed to the light irradiation device 213B while maintaining the smectic liquid crystal phase. Will be done. By 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 present polarizing film is continuously formed on the photoalignment film.

The continuously formed polarizing film is wound around the second winding core 220A as a laminated body including the transparent substrate and the photoalignment film, and the form of the second roll 220 is obtained. When winding the formed main polarizing film to obtain a second roll, winding may be performed using an appropriate spacer.

In this way, the transparent substrate 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, whereby the transparent substrate is passed. The present polarizing film is continuously manufactured on the above photoalignment film.

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

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

The configuration and manufacturing method of the present polarizing film have been described above mainly in the form of the laminated body of the transparent substrate / the photoalignment film / the main polarizing film. The photoalignment film or the transparent substrate may be peeled off from the laminate, or a layer or film other than the transparent substrate / photoalignment film / main polarizing film may be laminated. As for these layers and films, as described above, the present polarizing film may further include a retardation film, and may further include an antireflection layer or a luminance improving film.

Further, by using the transparent substrate itself as a retardation film, it is possible to obtain a circular polarizing plate or an elliptical polarizing plate in the form of a retardation film / photoalignment film / main polarizing film. For example, when a uniaxially stretched 1/4 wave plate is used as the retardation film, the irradiation direction of the polarized UV is set to be approximately 45 ° with respect to the transport direction of the transparent substrate, thereby rolling-to. -It is possible to make a circularly polarizing plate with Roll. As the 1/4 wave plate used in manufacturing the circularly polarizing plate as described above, it is preferable that the in-plane phase difference value with respect to visible light has a characteristic that the in-plane retardation value becomes smaller as the wavelength becomes shorter.

Further, using a 1/2 wave plate as a retardation film, a linear polarizing plate roll having a retarded angle between the slow axis and the absorption axis of the polarizing film was produced, and the surface on which the polarizing film was formed was formed. It is also possible to form a wide-band circular polarizing plate by further forming a 1/4 wave plate on the opposite side.

<Use of this polarizing film>
This polarizing film can be used in various display devices. The 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, an electric field emission display device (FED), and a surface electric field emission display device (SED). )), Electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection type display device (for example, display device having a grating light valve (GLV) display device, digital micromirror device (DMD)) and Examples thereof include a piezoelectric ceramic display. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct-view type liquid crystal display device, a projection type liquid crystal display device, and the like. These display devices may be display devices that display two-dimensional images, or may be stereoscopic display devices that display three-dimensional images.
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 liquid crystal display device”) 10 using the polarizing film. The liquid crystal layer 17 is sandwiched between two groups 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, referred to as “the present EL display device” in some cases).
FIG. 11 is a schematic diagram schematically showing the configuration of a projection type liquid crystal display device using the present polarizing film.

First, the liquid crystal display device 10 shown in FIG. 2 will be described.
A color filter 15 is arranged on the liquid crystal layer 17 side of the base material 14a. The color filter 15 is arranged at a position facing the pixel electrodes 22 across the liquid crystal layer 17, and the black matrix 20 is arranged at a position facing the boundary between the pixel electrodes. The transparent electrode 16 is arranged 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.

The thin film transistor 21 and the pixel electrode 22 are regularly arranged on the liquid crystal layer 17 side of the base material 14b. The pixel electrode 22 is arranged 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 arranged between the thin film transistor 21 and the pixel electrode 22.

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

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

A liquid crystal layer 17 is arranged between the transparent electrode 16 and the pixel electrode 22. A spacer 23 is arranged on the liquid crystal layer 17 in order to keep the distance between the base material 14a and the base material 14b constant. Although the spacer is shown as a columnar spacer in FIG. 2, the spacer is not limited to the columnar shape, and the shape is arbitrary as long as the distance between the base material 14a and the base material 14b can be kept constant.

Of the layers formed on the base material 14a and the base material 14b, the alignment layer for orienting the liquid crystal in a desired direction may be arranged on the surface in contact with the liquid crystal layer 17. The polarizing film may be arranged inside the liquid crystal cell, that is, the polarizing film may be arranged on the surface side in contact with the liquid crystal layer 17. Such a format is hereinafter referred to as an "in-cell format".

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

Of the base material 14a and the base material 14b sandwiching the liquid crystal layer 17, on the outside of the base material 14a and the base material 14b, the polarizing elements 12a and 12b are provided, and at least one of them is a polarizing element. This polarizing film is included in.
Further, it is preferable that the retardation layers (for example, 1/4 wave plate and optical compensation film) 13a and 13b are laminated. By arranging the present polarizing film on the polarizing element 12b among the polarizing elements 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 the liquid crystal compound contained in the liquid crystal layer 17, and the transparent base material is the retardation film, and the present polarized light is used. When a (elliptical) circularly polarizing plate including a film is used, the retardation film can be used as the 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 emitting side (outside) of the polarizing element including the main polarizing film.
Further, an antireflection film for preventing reflection of external light may be arranged on the outside of the polarizing element including the main polarizing film (when the polarizing film is further provided on the outside of the polarizing film).

As described above, the polarizing film can be used for the polarizing elements 12a or 12b of the liquid crystal display device 10 of FIG. By providing the polarizing film on the polarizing elements 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 polarizing element 12a or 12b, the stacking order thereof is not particularly limited. This will be described with reference to the enlarged view of the portions A and B surrounded by the dotted line in FIG.

FIG. 3 is an enlarged schematic cross-sectional view of a portion A in FIG. (A1) of FIG. 3 is provided so that the main polarizing film 3, the photoalignment film 2 and the transparent substrate 1 are arranged in this order from the retardation layer 13a side when the polarizing element 100 is used as the polarizing element 12a. Show that it is. Further, FIG. 3A2 shows that the transparent substrate 1, the photoalignment film 2, and the main polarizing film 3 are provided so as to be arranged in this order from the retardation layer 13a side.

FIG. 4 is an enlarged schematic view of a portion B in FIG. In FIG. 4B1, when the polarizing element 100 is used as the polarizing element 12b, the transparent substrate 1, the photoalignment film 2 and the main polarizing film 3 are arranged in this order from the retardation film 13b side. .. In FIG. 4B2, when the polarizing element 100 is used as the polarizing element 12b, the main polarizing film 3, the photoalignment film 2 and the transparent substrate 1 are arranged in this order from the retardation film 13b side. ..

A backlight unit 19, which is a light emitting source, is arranged outside the polarizing element 12b.
The backlight unit 19 includes a light source, a light guide body, a reflector, a diffusion sheet, and a viewing angle adjusting sheet. Examples of the light source include electroluminescence, cold cathode fluorescent lamp, hot cathode fluorescent lamp, light emitting diode (LED), laser light source, mercury lamp and the like. In addition, the type of the polarizing film can be selected according to the characteristics of such a light source.

When the liquid crystal display device 10 is a transmissive liquid crystal display device, the white light emitted from the light source in the backlight unit 19 enters the light guide body, changes its course by the reflector, and is diffused by the diffusion sheet. There is. The diffused light is adjusted to have a desired directivity by the viewing angle adjusting sheet, and then is incident on the polarizing element 12b from the backlight unit 19.

Of the unpolarized incident light, only one of the linearly polarized light passes through the polarizing element 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, the orientation state of the liquid crystal molecules contained in the liquid crystal layer 17 changes 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, and the brightness of the light emitted from the liquid crystal display device 10 is controlled. Will be done. When the liquid crystal layer 17 is in an oriented state in which polarized light is transmitted as it is, the polarized light passes through the liquid crystal layer 17 and the transparent electrode 16, and light in a specific wavelength range passes through the color filter 15 and reaches the polarizing element 12a. Therefore, the liquid crystal display device displays the brightest color determined by the color filter.

On the contrary, when the liquid crystal layer 17 is in an oriented state in which 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 polarizing element 12a. As a result, this pixel displays black. In the orientation state between these two states, the brightness of the light emitted from the liquid crystal display device 10 is also between the above two states, so that the pixel displays an intermediate color.

When the liquid crystal display device 10 is a semi-transmissive liquid crystal display device, it is preferable to use one in which a 1/4 wave plate is further laminated on the polarizing layer side of the polarizing film (circular polarizing plate). At this time, the pixel electrode 22 has a transmissive portion made of a transparent material and a reflective portion made of a material that reflects light. Is displayed. On the other hand, in the reflecting portion, external light is incident on the liquid crystal display device, and due to the action of the 1/4 wave plate further provided on the main polarizing film, the circularly polarized light transmitted through the main polarizing film passes through the liquid crystal layer 17 and is a pixel electrode. It is reflected by 22 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 EL display device, it is preferable to use the present polarizing film after forming the present polarizing film into a circular polarizing plate (hereinafter, sometimes referred to as “the present circular polarizing plate”). The circularly polarizing plate usually has two embodiments. Therefore, before explaining the configuration of the EL display device 30, 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 (phase difference film) 4 is further provided on the main polarizing film 3 in the polarizing element 100. FIG. 6B is a cross-sectional view schematically showing a second embodiment of the circularly polarizing plate 110. In this second embodiment, as the transparent base material 1 used in manufacturing the polarizing element 100, the transparent base material 1 (phase difference film 4) to which the retardation property has been imparted in advance is used, so that the transparent base material 1 is used. This circularly polarizing plate 110 is such that 1 itself also has a function as a retardation layer 4.

Here, a method for manufacturing the circularly polarizing plate 110 will be described. As described in the second embodiment of the circular polarizing plate 110, in the present manufacturing method for manufacturing the present polarizing film 100, the transparent base material 1 to which the retardation property is given in advance as the transparent base material 1, that is, the retardation film is used. It can be manufactured by using it. In the first embodiment of the circular polarizing plate 110, the retardation layer 4 may be formed by laminating a retardation film on the polarizing film 3 manufactured by the manufacturing method B. When the main polarizing film 100 is manufactured in the form of the second roll 220 by the present manufacturing method B, the main polarizing film 100 is unwound from the second roll 220, cut to a predetermined size, and then cut. A retardation film may be attached to the main polarizing film 100, but the shape is film-like and long by preparing a third roll in which the retardation film is wound around a winding core. The circularly polarizing plate 110 can also be continuously manufactured.

A method for continuously manufacturing the first embodiment of the circularly polarizing plate 110 will be described with reference to FIG. 7. Such a manufacturing method
A step of continuously unwinding the polarizing film 100 from the second roll 220 and continuously unwinding the retardation film from the third roll 230 on which the retardation film is wound.
The polarizing layer provided on the polarizing film 100 unwound from the second roll 220 and the retardation film unwound from the third roll are continuously bonded to form the circular polarizing plate 110. The process of forming and
This comprises a step of winding the formed circularly polarizing plate 110 around a fourth winding core 240A to obtain a fourth roll 240.

The method for manufacturing the first embodiment of the circularly polarizing plate 110 has been described above. However, when the main polarizing film 3 in the polarizing element 100 and the retardation film are bonded to each other, an appropriate adhesive is used. The polarizing film 3 and the retardation film may be bonded to each other via an adhesive layer formed from the adhesive.

Subsequently, the EL display device provided with the circularly polarizing plate 110 will be described with reference to FIG.
In the EL display device 30, the organic functional layer 36, which is a light emitting source, and the cathode electrode 37 are laminated on the base material 33 on which the pixel electrode 35 is formed. A circularly polarizing plate 31 is arranged on the side opposite to the organic functional layer 36 with the base material 33 interposed therebetween, 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, which is a light emitting source, is composed of an electron transport layer, a light emitting layer, a hole transport layer, and the like. The light emitted from the organic functional layer 36 passes through the pixel electrode 35, the interlayer insulating film 34, the 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, it may be applied to the inorganic EL display device having the inorganic functional layer.

In order to manufacture the EL display device 30, first, the thin film transistor 40 is formed on the base material 33 in a desired shape. Then, the interlayer insulating film 34 is formed into a film, and then the pixel electrode 35 is formed into a film by a sputtering method and patterned. After that, the organic functional layer 36 is laminated.

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

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

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

A wiring electrode for the thin film transistor 40 is provided on the base material 33. The wiring electrode has a low resistance and has a function of electrically connecting to the pixel electrode 35 to suppress the resistance value. Generally, the wiring electrode is Al, Al and a transition metal (excluding 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 forming an inorganic material such as silicon oxide such as SiO 2} or silicon nitride by sputtering or vacuum vapor deposition, a silicon oxide layer formed by SOG (spin on glass), a photoresist, and a polyimide. Any material may be used as long as it has insulating properties, such as a coating film of a resin-based material such as acrylic resin.

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

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

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 , but ITO and IZO are particularly preferable. The thickness of the pixel electrode 35 may be a certain thickness or more capable of sufficiently injecting holes, and is preferably about 10 to 500 nm.
The pixel electrode 35 can be formed by a vapor deposition method (preferably a sputtering method). The sputter 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 the 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%) and the like are preferable.
The cathode electrode 37 is formed by a vapor deposition method, a sputtering method, or the like. The thickness of the cathode electrode 37 is preferably 0.1 nm or more, preferably 1 to 500 nm or more.

The hole injection layer has a function 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 interfering with electrons, and has a charge injection layer and a charge. Also called the transport layer.
The thickness of the light emitting layer, the combined thickness of the hole injection layer and the hole transport layer, and the thickness of the electron injection transport layer are not particularly limited and vary depending on the forming method, but should be about 5 to 100 nm. Is preferable. Various organic compounds can be used for the hole injection layer and the hole transport layer. A vacuum vapor deposition method can be used to form the hole injection transport layer, the light emitting layer, and the electron injection transport layer in that a homogeneous thin film can be formed.

The organic functional layer 36, which is a light emitting source, is one that utilizes light emission (fluorescence) from a single-term excitator, one that utilizes light emission (phosphorescence) from a triple-term excitator, and one from a single-term excitator. Those that utilize light emission (fluorescence) and those that utilize light emission (phosphorescence) from triplet excitators, those formed by organic substances, those formed by organic substances and those formed by inorganic substances. , A high molecular weight material, a low molecular weight material, a high molecular weight material and a low molecular weight material, and the like can be used. However, the present invention is not limited to this, and an organic functional layer 36 using various known EL elements can be used in the EL display device 30.

A desiccant 38 is arranged 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 deterioration of the organic functional layer 36.

FIG. 10 is a schematic view 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 also obtain emitted light from the opposite surface of the array substrate.
As the thin film encapsulating film 41, it is preferable to use a DLC film in which DLC (diamond-like carbon) is vapor-deposited on the film of the electrolytic capacitor. The DLC film has a characteristic of extremely poor moisture permeability and has high moisture-proof performance. Further, a DLC film or the like may be formed by directly vapor deposition on the surface of the cathode electrode 37. Further, the thin film encapsulating film 41 may be formed by laminating a resin thin film and a metal thin film in multiple layers.

As described above, a novel polarizing film (the present polarizing film) according to the present invention and a new display device (the present liquid crystal display device and the present EL display device) provided with 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 polarizing element 142 and / or the polarizing element 143 of this projection type liquid crystal display device.

The light flux emitted from the light source (for example, a high-pressure mercury lamp) 111, which is a light emitting source, first passes through the first lens array 112, the second lens array 113, the polarization conversion element 114, and the superimposed lens 115. Luminance is made uniform and polarized in the anti-light bundle cross section.

Specifically, the ray bundle emitted from the light source 111 is divided into a large number of minute ray bundles by the first lens array 112 in which the minute lenses 112a are formed in a matrix. The second lens array 113 and the superimposed lens 115 are provided so that each of the divided light fluxes illuminates the entire three liquid crystal panels 140R, 140G, 140B to be illuminated, and therefore each of them. The entire surface of the incident side of the liquid crystal panel has almost uniform illuminance.

The polarization conversion element 114 is composed of a polarization beam splitter array and is arranged between the second lens array 113 and the superimposing lens 115. As a result, the random polarized light from the light source is converted into polarized light having a specific polarization direction in advance, the light amount loss in the incident side polarizing element described later is reduced, and the brightness of the screen is improved.

The light uniformed in brightness and polarized as described above is sequentially converted into a red channel, a green channel, and a blue channel by dichroic mirrors 121, 123, and 132 for separating into three primary colors of RGB via a reflection mirror 122. They are separated and incident on the liquid crystal panels 140R, 140G, and 140B, respectively.

In the liquid crystal panels 140R, 140G, 140B, a polarizing element 142 is arranged on the incident side thereof, and a polarizing element 143 is arranged on the emitting side thereof. The present polarizing film can be used for the polarizing element 142 and the polarizing element 143.

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

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

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

Electronic papers are represented by molecules such as optical anisotropy and dye molecular orientation, those represented by particles such as electrophoresis, particle movement, particle rotation, and phase change, and one end of the film moves. This includes those displayed by the color development / phase change of the molecule, those displayed by the light absorption of the molecule, and those displayed by self-luminous combination of electrons and holes. More specifically, microcapsule type electrophoresis, horizontal moving type electrophoresis, vertical moving type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electron powder fluid, magnetic migration type, magnetic heat sensitivity. Formula, electrowetting, light scattering (transparent / white turbidity change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, strong dielectric liquid crystal, two-color dye / liquid crystal dispersion type, movable film, leuco dye Coloring and erasing by, photochromic, electrochromic, electrodeposition, flexible organic EL and the like can be mentioned. The electronic paper may be used not only for personal use of texts and images, but also for display of advertisements (signage) and 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 such as 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 by way of examples. Unless otherwise specified, "%" and "part" in the example are 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) is described in Lubet al. Recl. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).

[Measurement of phase transition temperature]
The phase transition temperature of compound (1-6) was confirmed by determining the phase transition temperature of the membrane composed of compound (1-6). The operation is as follows.
A film made of compound (1-6) is formed on the alignment film formed on the glass substrate, and the phase transition temperature is confirmed by observing the texture with a polarizing microscope (BX-51, manufactured by Olympus Corporation) while heating. did. The film composed of the compound (1-6) undergoes a phase transition to the nematic phase at 112 ° C., a phase transition to the smectic A phase at 110 ° C., and a phase transition to the smectic B phase at 94 ° C. after raising the temperature to 120 ° 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). After raising the temperature to 140 ° C., the compound (1-7) had a phase transition to the nematic phase at 133 ° C., a phase transition to the smectic A phase at 118 ° C., and a 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 this composition, etc.]
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; 75 parts of compound (1-6)
Compound (1-7) 25 parts Dichroic dye; Compound (2-1-1) 2.5 parts D10 dye described in Japanese Patent No. 3688130

Polymerization initiator;
1-Hydroxy-cyclohexyl-phenylketone (Irgacure 184; Ciba Specialty Chemicals) 6 parts Leveling agent; BYK-361N (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]
Similar to the case of compound (1-6) and compound (1-7), the phase transition temperature of the polymerizable liquid crystal compound contained in the present composition prepared as described above was determined. After raising the temperature to 140 ° C, when the temperature is lowered, the phase transitions to the nematic phase at 109 ° C without forming a phase-separated state, and the phase transition to the smectic A phase at 98 ° C without forming a phase-separated state, and at 74 ° C. It was confirmed that the phase transition to the smectic B phase was performed without forming a phase-separated state.

[Manufacturing and evaluation of this polarizing film]
1. 1. Formation of alignment film A glass substrate was used as the transparent substrate.
A 2% by mass aqueous solution (composition for forming an alignment layer) of polyvinyl alcohol (polyvinyl alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) is applied onto the glass substrate by a spin coating method, dried, and then dried. A film having a thickness of 100 nm was formed. Subsequently, the surface of the obtained film was subjected to a rubbing treatment to form an alignment layer to prepare a polarizing film. The rubbing process uses a semi-automatic rubbing device (trade name: LQ-008 type, manufactured by Joyo Engineering Co., Ltd.) and a cloth (trade name: YA-20-RW, manufactured by Yoshikawa Kako Co., Ltd.) with a pushing amount of 0.15 mm. The procedure was carried out under the conditions of a rotation speed of 500 rpm and 16.7 mm / s. By such a rubbing treatment, a laminated body 1 having an alignment film formed on a glass substrate was obtained.

2. 2. Formation of polarizing film The composition for forming a polarizing film was applied onto the alignment film of the laminate 1 by a spin coating method, heated and dried on a hot plate at 120 ° C. 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 the smectic B phase. Next, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd. ^{), the coating film is irradiated with ultraviolet rays at an exposure amount of 2000 mJ / cm 2} (313 nm standard) to polymerize the coating film contained in the coating film. The liquid crystal 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 measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) and found to be 1.6 μm.

3. 3. X-ray diffraction measurement X-ray diffraction measurement was performed on the obtained polarizing film using an X-ray diffractometer X'Pert PRO MPD (manufactured by Spectris Co., Ltd.). Using Cu as a target, X-rays generated under the 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 divergence slit 1/2 °, and the scanning range is 2θ = 4.0 to 40. As a result of scanning and measuring in the range of 0.0 ° in steps of 2θ = 0.01671 °, a sharp Bragg peak with a peak half-value width (FWHM) = about 0.1718 ° was found near 2θ = 20.24 °. Obtained. Further, the same result was obtained even when the incident film was incident from a direction parallel to the surface of the polarizing film and perpendicular to the orientation direction. The ordered period (d) obtained from the peak position was about 4.4 Å, and it was found that a structure reflecting the higher-order smectic phase was formed.

4. Measurement of two-color ratio (DR) The two-color ratio was measured as follows.
Absorbance in the transmission axis direction (A ¹ ) and absorbance in the absorption axis direction (A ² ) at the maximum absorption wavelength were measured using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) with a folder with a polarizing element set. It was measured by the double beam method. The folder was provided with a mesh that cuts the amount of light 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 the absorbance ^{(A 2} ) in the absorption axis direction, and used as the ^{two-color ratio.} It can be said that the higher the two-color ratio, the better the characteristics as a polarizing film. Table 1 shows the maximum absorption wavelength of the absorbance (A ² ) in the absorption axis direction and the measurement results of the two-color ratio at that wavelength.

5. Measurement of Haze value In order to confirm the transparency of this polarizing element, 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.

In Examples 2 to 6, Example 8, Reference Example 1, and Comparative Examples 1 and 2, the present composition was prepared in the same manner except that the type and content of the polymerizable non-liquid crystal compound were changed. Further, in Comparative Example 3, a composition was prepared under the condition that a polymerizable non-liquid crystal compound was not added, and after coating and drying at 120 ° C., the polarizing film was rapidly moved onto a hot plate at 70 ° C. and then exposed to UV to obtain a polarizing film. Made. The results of each measurement are 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 type and content of the polymerizable non-liquid crystal compound were changed. Made. The results of each measurement are shown in Table 1.

Examples 1 to 15 showed good horizontal orientation and high dichroism without forming a phase-separated state. Good horizontal orientation 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 display devices (displays). Therefore, the present composition capable of producing the present polarizing film has high industrial value.

1 Transparent substrate 2 Photo-alignment film 3 Polarizing film 4 Phase difference layer 100 Polarizer 210 1st roll 210A Winding core 220 2nd roll 220A Winding core 230 3rd roll 230A Winding core 240 4th roll 240A Winding 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 11 Antireflection layer 12a, 12b Polarizer 13a, 13b Phase difference film 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 22 Pixel electrode 23 Spacer 24 Liquid crystal display 30 EL display device 31 Circular polarizing plate 33 Base material 34 Interlayer insulating film 35 Pixel electrode 36 Light emitting layer 37 Cone electrode 38 Drying Agent 39 Sealing lid 40 Thinning film 41 Rib 42 Thinning 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 Superimposition lens 121, 123, 132 Dichroic mirror 122 Reflection Mirror 140R, 140G, 140B Liquid crystal panel 142,143 Polarizer 150 Cross dichroic prism 170 Projection lens 180 screen

Claims (8)

It contains a polymerizable liquid crystal compound, a polymerizable non-liquid crystal compound which is a polyfunctional acrylate, an azo dye, a polymerization initiator and a solvent.
The following (A), (B) and meets the requirements of (C) is formed from a polarizing film-forming composition, have a 5% of Haze value, the polymerization of the smectic liquid crystal phase of the polymerizable liquid crystal compound A polarizing film containing an object.
(A) Both the polymerizable liquid crystal compound and the polymerizable non-liquid crystal compound have the same 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-separated state, and the phase changes from the nematic liquid crystal phase to the smectic liquid crystal phase. The transition temperature is 40 ° C to 200 ° C;
(C) 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 polarizing film according to claim 1, wherein the polymerizable liquid crystal compound contained in the polarizing film forming composition 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 independent of each other and may have a substituent 1,4-phenylene group or a cyclohexane-1,4-diyl which may have a substituent. Represents a group, provided that ^{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. is -O - - -CH ₂ constituting, - optionally replaced by S- or -NR- .R is .Y ¹ and ^{Y 2} represents an alkyl group or a phenyl group having 1 to 6 carbon atoms, 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−, ^Ra and R ^b independently of each other represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. U ¹ represents a hydrogen atom or a polymerizable group. U ² represents a polymerization. Represents a sex group. W ¹ and W ² represent a single bond, -O-, -S-, -COO- or -OCOO- ^{independently of each other. V 1} and V ² represent a substituent independently of each other. Represents an alcandiyl group having 1 to 20 carbon atoms which may have, and —CH ₂ − constituting the alcandiyl group may be replaced with —O—, —S— or −NH−. ) The polymerizable group of the polymerizable liquid crystal compound contained in the composition for forming a polarizing film and the polymerizable group of the polymerizable non-liquid crystal compound are both an acryloyloxy group (CH ₂ = CHCOO−) or a methacryloyloxy group (CH). The polarizing film according to claim 1 or 2, wherein ₂ = C (CH _{3) COO−).} The polarizing film according to any one of claims 1 to 3, wherein the polymerizable group of the polymerizable liquid crystal compound contained in the composition for forming a polarizing film and the polymerizable group of the polymerizable non-liquid crystal compound are the same. Claimed that the polymerizable liquid crystal compound contained in the composition for forming a polarizing film 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. Item 4. The polarizing film according to any one of Items 1 to 4. The method for producing a polarizing film according to any one of claims 1 to 5, which comprises the following steps (I), (II) and (III).
(I) A step of applying the polarizing film forming composition according to any one of claims 1 to 5 onto a substrate or an alignment film formed on the substrate, and removing the solvent to form a coating film. ;
(II) A step of bringing the polymerizable liquid crystal compound contained in the coating film formed in (I) into a smectic liquid crystal phase state;
(III) A step of copolymerizing a polymerizable liquid crystal compound and a polymerizable non-liquid crystal compound in a coating film in which the polymerizable liquid crystal compound formed in (II) is in a smectic liquid crystal phase state. The method for producing a polarizing film according to claim 6, wherein the base material is a transparent base material that has been subjected to an orientation treatment. The step (II) is a step (II-1) of heat-treating until the polymerizable liquid crystal compound contained in the coating film formed in the step (I) shows a nematic liquid crystal phase, and a step (II-1). 6. The method for manufacturing a polarizing film according to.

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