TW201923393A - Polarizing film and method for manufacturing same - Google Patents

Abstract

This polarizing film comprises a liquid crystal layer. The liquid crystal layer contains a liquid crystal compound, and comprises at least two regions that are distinguished by color correction polarization value. The at least two regions have different dichroic pigment contents.

Description

Polarizing film and manufacturing method thereof

The present invention relates to a polarizing film and a manufacturing method thereof, and more particularly, to a polarizing film having a layer containing a liquid crystal compound and a dichroic pigment and a manufacturing method thereof.

Compared with liquid crystal display devices, organic EL (Electroluminescence) display devices using organic light-emitting diodes (OLEDs) can not only reduce weight or thickness, but also achieve a wide range of viewing angles and faster response. Speed, high contrast and other high image quality, so it is used in various fields such as smart phones or TVs, digital cameras. It is known that in organic EL display devices, a circular polarizing plate or the like is used to improve the anti-reflection performance in order to suppress the decrease in visibility caused by the reflection of external light.

The polarizing film used in such a circular polarizing plate is disclosed in Japanese Patent Laid-Open Publication No. 2015-206852 (Patent Document 1) and Japanese Patent Laid-Open Publication No. 2015-212823 (Patent Document 2). A patterned polarizing film of a patterned liquid crystal hardened film is laminated.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-206852
[Patent Document 2] Japanese Patent Laid-Open No. 2015-212823

[Problems to be solved by the invention]

An object of the present invention is to provide a novel polarizing film having at least two regions having mutually different values of visual sensitivity correction polarization degrees and a method for manufacturing the same.
[Technical means to solve the problem]

The present invention provides a polarizing film and a method for manufacturing the same as described below.
[1] A polarizing film, which has a liquid crystal layer, and the liquid crystal layer contains a liquid crystal compound and has at least two regions that are distinguished according to the value of the polarization correction value of the visual sensitivity,
The contents of the dichroic pigments in the at least two regions are different from each other.
[2] The polarizing film according to [1], further comprising a base material layer and an alignment layer laminated on at least one side of the base material layer, and the liquid crystal layer is laminated on the alignment layer.
[3] The polarizing film according to [2], wherein the alignment layer contains a photo-alignment polymer.
[4] The polarizing film according to any one of [1] to [3], wherein the liquid crystal compound contains a polymerizable liquid crystal compound.
[5] The polarizing film according to any one of [1] to [4], wherein the liquid crystal layer has a first region containing a dichroic pigment and a content ratio of the dichroic pigment is lower than that of the second region in the first region region,
The above-mentioned first area has a visual sensitivity correction polarization of 90% or more.
The visual sensitivity correction polarization in the second region is 10% or less.
[6] The polarizing film according to any one of [1] to [5], wherein the liquid crystal layer has a first region containing a dichroic pigment and a content ratio of the dichroic pigment is lower than that of the second region in the first region region,
The visual sensitivity correction unit transmittance of the first region is 35% or more.
The visual sensitivity correction unit transmittance of the second region is 80% or more.
[7] The polarizing film according to [5] or [6], wherein the plan view shape of the second region is a circle, an oval, an oval, or a polygon,
When the second area is circular, the diameter is 5 cm or less.
When the second area is oval or oblong, the long diameter is 5 cm or less.
In the case where the second region is a polygon, the diameter of the imaginary circle drawn by the polygon inscribed above is 5 cm or less.
[8] The polarizing film according to any one of [5] to [7], wherein the first region shows a Blegg peak in an X-ray diffraction measurement.
[9] The polarizing film according to any one of [1] to [8], which further has a base material layer,
The base material layer has a 1/4 wavelength plate function.
[10] The polarizing film according to any one of [1] to [9], wherein a length of the polarizing film is 10 m or more.
[11] A circular polarizing plate, which is formed by laminating a polarizing film according to any one of [1] to [8] and [10] and a retardation having a 1/4 wavelength plate function.
[12] A method for manufacturing a polarizing film, including the following steps:
The preparation step is to prepare a laminated film having a polarizing layer containing a liquid crystal compound and a dichroic dye on at least one side of the base material layer; and a liquid contacting step is to make a part of the polarizing layer of the laminated film The region is in contact with a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer, and the content of the dichroic pigment is reduced in a part of the region of the polarizing layer.
[13] The method for manufacturing a polarizing film according to [12], wherein the liquid-liquid contacting step includes the following steps:
The protective layer lamination step is obtained by laminating the polarizing layer on the polarizing layer of the laminating film prepared in the preparing step with a protective layer for covering the polarizing layer and an exposed area for exposing the polarizing layer. Laminated film with protective layer;
The decoloring step is to obtain a dichroic pigment in a partial region of the polarizing layer by contacting the laminated film with a protective layer and a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer. A decolored laminated film having a reduced content rate; and a peeling step, which peels off the protective layer from the decolored laminated film.
[14] The method for manufacturing a polarizing film according to [13], wherein the plan view shape of the exposed area in the protective layer is circular, oval, oblong, or polygonal,
When the exposed area is circular, the diameter is 5 cm or less.
In the case where the above-mentioned exposed area is oval or oblong, the long diameter is 5 cm or less,
In the case where the exposed area is polygonal, the diameter of the imaginary circle drawn in the manner of the polygon inscribed above is 5 cm or less.
[15] The method for manufacturing a polarizing film according to any one of [12] to [14], wherein the preparation step includes the following steps:
The alignment layer forming step is to form an alignment layer by applying the composition for forming an alignment layer on one side of the substrate layer; and the polarizing layer forming step is to a surface of the substrate layer on the side where the alignment layer is formed. A polarizing layer-forming composition containing the liquid crystal compound and the dichroic dye is applied to form the polarizing layer.
[16] The method for producing a polarizing film according to [15], wherein the composition for forming an alignment layer contains a photo-alignment polymer,
The alignment layer forming step is performed by applying polarized light to an application layer for an alignment layer formed by applying the composition for forming an alignment layer to form the alignment layer.
[17] The method for producing a polarizing film according to [15] or [16], wherein the liquid crystal compound is a polymerizable liquid crystal compound,
The step of forming the polarizing layer is to irradiate the coating layer for a polarizing layer formed by applying the composition for forming a polarizing layer with active energy rays to form the polarizing layer.
[18] The method for producing a polarizing film according to any one of [12] to [17], wherein a length of the polarizing film is 10 m or more.
[19] A method for manufacturing a circular polarizing plate, which includes a step of laminating a retardation layer, that is, a polarizing film manufactured by the method of manufacturing a polarizing film according to any one of [12] to [18] The retardation of the wavelength plate is laminated.
[20] The manufacturing method of the circular polarizing plate according to [19], wherein the polarizing film is a long polarizing film having a length of 10 m or more,
The phase difference layer is a long phase difference layer with a length of 10 m or more.
The step of laminating the phase difference is to form a long laminated body by laminating the long polarizing film and the long phase difference,
Furthermore, it has a cutting step of cutting the said long laminated body into a single piece.
[Effect of the invention]

According to the present invention, it is possible to provide a polarizing film having at least two regions having mutually different values of the visual acuity correction polarization degrees and a method for manufacturing the same.

Hereinafter, preferred embodiments of the polarizing film and the manufacturing method thereof according to the present invention will be described with reference to the drawings. In addition, the scope of the present invention is not limited to the embodiments described herein, and various changes can be made without departing from the scope of the present invention.

<Polarizing film>
FIG. 1 (a) is a schematic plan view showing an example of the polarizing film of the present invention, and FIG. 1 (b) is a cross-sectional view taken along the line XX of FIG. 1 (a). The polarizing film 1 of this embodiment is a film having a function of light absorption anisotropy, and has a liquid crystal layer 11 containing a liquid crystal compound. The liquid crystal layer 11 has at least two regions that are distinguished according to the value of the visual sensitivity correction polarization (Py), and the content rates of the dichroic pigments in the at least two regions are different from each other. The polarizing film 1 includes a liquid crystal layer 11, but may further include a substrate layer 13, an alignment layer 12, and other layers. The polarizing film 1 shown in FIG. 1 (b) discloses an example in which the alignment layer 12 and the liquid crystal layer 11 are provided on one side of the base material layer 13, but the alignment layer and the liquid crystal may be provided on both sides of the base material layer 13. Floor. The structures of the liquid crystal layers provided on both sides of the substrate layer 13 may be the same as each other or different from each other.

The polarizing film 1 may be a long polarizing film having a length of 10 m or more. In this case, the polarizing film 1 may be a rolled body wound into a roll shape. The polarizing film can be continuously rolled out from the wound body, and steps such as a step of laminating with a retardation described below, a step of cutting into a single sheet, and the like can be performed. There is no particular limitation on the length of the long polarizing film to be a roll, as long as it is 10 m or more, and it may be, for example, 10,000 m or less.

(Liquid crystal layer)
The liquid crystal layer 11 contains a liquid crystal compound and has a region containing a liquid crystal compound and a dichroic dye. When the polarizing film 1 has the polarizing characteristics of the plane of the polarizing film 1, it is preferable that the polarizing film 1 has a region where the dichroic dye and the liquid crystal compound are horizontally aligned with respect to the plane of the polarizing film 1. When the polarizing layer 1 has polarizing characteristics in the film thickness direction of the polarizing film 1, it is preferable to have a region in which the dichroic dye and the liquid crystal compound are horizontally aligned with respect to the plane of the polarizing film 1.

The liquid crystal layer 11 contains a dichroic dye and a liquid crystal compound. As a region where the dichroic dye and the liquid crystal compound are horizontally aligned with respect to one surface of the polarizing film, the liquid crystal layer 11 is a liquid crystal alignment level for light having a wavelength of λ nm. The color ratio (= A1 (λ) / A2 (λ)) of the ratio of the absorbance A1 (λ) in the direction to the absorbance A2 (λ) in the vertical direction in the liquid crystal alignment plane is preferably 7 or more, and more preferably 20 The above is more preferably 30 or more. The higher the value, the more polarized light characteristics with excellent absorption selectivity. When the liquid crystal layer 11 is a nematic liquid crystal phase, the above ratio is about 5 to 10, but it varies depending on the type of the dichroic pigment. When the liquid crystal layer 11 is a nematic liquid crystal phase or a smectic liquid crystal phase, the liquid crystal compound and the two colors can be confirmed by, for example, observing the surface with various microscopes or measuring the scattering with a haze meter. Sex pigments are not phase separated.

As shown in FIGS. 1 (a) and 1 (b), the liquid crystal layer 11 includes a first region 11 a and a second region 11 b that are distinguished by correcting the polarization degree (Py) according to the visual sensitivity and by the content rate of the dichroic pigment. In the polarizing film 1 shown in FIG. 1 (a), an example is shown in which each of the two regions has two different regions with different visual sensitivity correction polarization (Py) and dichroic pigment content, but the first region and The second region may be two or more regions, and may include three or more regions having different content rates of dichroic pigments.

The first region 11a of the polarizing film 1 shown in FIG. 1 (a) contains a liquid crystal compound and a dichroic dye. The second region 11b contains a liquid crystal compound, and may or may not contain a dichroic pigment. When a dichroic pigment is contained, its content rate is preferably less than the dichroic content contained in the first region 11a. Content of pigment.

The content rate of the dichroic pigment in the liquid crystal layer 11 can be determined, for example, by measuring the absorbance of the absorption maximum wavelength (λ _MAX ) of the dichroic pigment.

The first region 11a is preferably a region having high polarization characteristics. For example, the visual sensitivity correction polarization (Py) may be 90% or more, preferably 92% or more, more preferably 95% or more, and usually 100% or less. . The visual sensitivity correction unit transmittance (Ty) of the first region 11a may be, for example, 35% or more, preferably 40% or more, more preferably 44% or more, and usually less than 50%.

The second region 11b is preferably a low-polarization region having a visual sensitivity-corrected polarization (Py) lower than the visual sensitivity-corrected polarization (Py) of the first region 11a. The visual sensitivity correction polarization (Py) of the second region 11b may be, for example, 10% or less, preferably 5% or less, more preferably 1% or less, or 0%. The second region 11b is preferably a visual sensitivity-corrected cell transmittance (Ty) higher than the visual sensitivity-corrected cell transmittance (Ty) of the first region 11a. The visual sensitivity correction monomer transmittance (Ty) of the second region 11b may be, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and usually 98% or less.

The visual sensitivity-corrected polarization (Py) and the visual sensitivity-corrected monomer transmittance (Ty) in this specification can be calculated based on the polarized light and the monomer transmittance measured using a spectrophotometer. For example, the spectrophotometer can be used for a device provided with a folder with a polarizing element to measure the transmission axis direction (alignment vertical direction) in the range of 380 nm to 780 nm as the visible light wavelength by the dual beam method. Transmittance (T ₁ ) and transmittance (T ₂ ) in the direction of the absorption axis (aligned in the same direction). The degree of polarization and monomer transmittance in the visible light range are calculated using the following formulae (Equation 1) and (Equation 2) at each wavelength, and the degree of polarization and monomer transmittance are calculated according to JIS Z 8701's 2-degree field of view (C light source). ) To perform visual sensitivity correction, thereby calculating the visual sensitivity correction unit transmittance (Ty) and visual sensitivity correction polarization (Py).

Polarization [%] = {(T ₁ －T ₂ ) / (T ₁ ＋ T ₂ )} × 100 (Equation 1)
Cell transmittance [%] = (T ₁ + T ₂ ) / 2 (Equation 2)

The occupied area of the first region 11 a and the occupied area of the second region 11 b may be appropriately selected depending on the characteristics required of the polarizing film 1. The ratio of the total occupied area of the first region 11a and the second region 11b to the surface area of the polarizing film 1 is preferably 90% or more, more preferably 95% or more, and still more preferably 99% or more. The occupied area of the first region 11a is preferably 50% or more, more preferably 70% or more, and even more preferably 80% of the total area of the occupied area of the first region 11a and the occupied area of the second region 11b. the above. For example, as shown in FIG. 1 (a), the occupied area of the second region 11b is smaller than the occupied area of the first region 11a and the first region 11a is provided so as to surround the second region 11b. In the polarizing film 1 shown in FIG. 1 (a), the first region 11 a is provided so as to surround a circular second region 11 b. However, a plurality of the second regions 11 b may be provided independently.

The shape of the first region 11a and the shape of the second region 11b are not particularly limited. For example, as shown in FIG. 1 (a), when the first region 11a is provided so as to surround the second region 11b, the shape of the second region 11b The shape in plan view can be formed into a circle; an ellipse; an oval; a polygon such as a triangle, a square, a rectangle, a rhombus; a shape of a letter; a combination of these and other arbitrary shapes.

The planar shape of the second region 11b is preferably circular, oval, oblong, or polygonal. When the second region 11b is circular, its diameter is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the second region 11b is oval or oblong, its long axis is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. In the case where the second region 11b is polygonal, the diameter of the imaginary circle drawn in the polygonal inscribed manner is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. The second region 11b having the above-mentioned shape can be preferably used as a region corresponding to a lens position of a camera provided on a smart phone or a tablet. At this time, the second region 11b can be reduced by setting the second region 11b to a region where the visual sensitivity correction polarization (Py) is 10% or less and the visual sensitivity correction unit transmittance (Ty) is 80% or more. It can improve the performance of the camera due to its excellent color transparency.

Furthermore, the first region 11a and the second region 11b may be provided so that their respective planar shapes are linear, band-shaped, or wavy. In this case, a plurality of first regions 11a and second regions 11b may be provided alternately. In this case, the widths of the first region 11a and the second region 11b are independent, preferably 1 μm to 10 mm, more preferably 1 μm to 1 mm, and even more preferably 1 μm to 100 μm.

Furthermore, in the case where the polarizing film is a long polarizing film, the long polarizing film is usually cut to a specific size according to the use of the polarizing film, etc., so it is preferably a specific position of the polarizing film after cutting In the method of forming the first region 11a or the second region 11b, the arrangement of the first region 11a or the second region 11b of the long polarizing film is set. For example, when the polarizing film after cutting is the polarizing film 1 shown in FIG. 1 (a), it is preferable to set a plurality of first polarizing films at a specific interval in the length direction and / or the width direction of the long polarizing film. 2 area 11b.

The thickness of the first region 11a of the liquid crystal layer 11 is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 5 μm or less, and even more preferably 3 μm or less. The thickness of the second region 11b of the liquid crystal layer 11 is preferably the same as that of the first region 11a, and is preferably 0.5 μm or more, more preferably 1 μm or more, and further preferably 5 μm or less, and more preferably 3 μm or less. The thickness of the liquid crystal layer 11 can be measured by an interference film thickness meter, a laser microscope, a stylus film thickness meter, or the like.

The thickness of the second region 11b may be smaller than the thickness of the first region 11a, but the difference between the thickness of the first region 11a and the thickness of the second region 11b is preferably 2 μm or less, more preferably 1 μm or less, and further preferably 0.5 μm. the following. By making the thicknesses of the first region 11a and the second region 11b of the liquid crystal layer 11 to be the same, the step difference between the first region 11a and the second region 11b is reduced, and the following retardation layer or the like is laminated on the liquid crystal layer 11. In the case of a layer (surface protection layer, etc.), it is possible to suppress the troubles such as the embedding of bubbles and the generation of wrinkles. Further, when the polarizing film 1 having the liquid crystal layer 11 is rolled into a roll shape, it is also possible to suppress defects such as the formation of curl marks.

(Liquid crystal compound)
As the liquid crystal compound contained in the liquid crystal layer 11, a known liquid crystal compound can be used. The type of the liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a disc-shaped liquid crystal compound, and a mixture thereof can be used. The liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof.

As the liquid crystal compound, a polymerizable liquid crystal compound is preferably used. By using a polymerizable liquid crystal compound, the hue of the polarizing film can be controlled arbitrarily, and the polarizing film can be significantly thinned. Moreover, since a polarizing film can be manufactured without performing an extending | stretching process, it can be set as the non-stretchable polarizing film which does not generate | occur | produce extensional relaxation by a heat | fever.

The polymerizable liquid crystal compound refers to a compound having a polymerizable group and having liquid crystallinity. The polymerizable group refers to a group participating in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in a polymerization reaction by a living radical or an acid generated from a photopolymerization initiator described below. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, a propenyloxy group, a methacryloxy group, an ethylene oxide group, Oxetanyl and the like. Among them, acryloxy, methacryloxy, ethyleneoxy, ethylene oxide, and oxetanyl are preferred, and acryloxy is more preferred. The liquid crystal property may be a thermotropic liquid crystal or a lyotropic liquid crystal. When the liquid crystal layer is mixed with a dichroic dye like the liquid crystal layer of the embodiment, it is preferable to use a thermotropic liquid crystal.

When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound that displays a nematic liquid crystal phase or a thermotropic liquid crystal compound that displays a smectic liquid crystal phase. When the liquid crystal layer 11 exhibits a polarizing function as a polymer film obtained by a polymerization reaction, the liquid crystal state displayed by the polymerizable liquid crystal compound is preferably a smectic phase, and from the viewpoint of high performance, it is more preferably a high order Stratophase. Among them, it is more preferable to form smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, and smectic K phase. The higher-order smectic liquid crystal compound of the smectic L phase is more preferably a higher-order smectic liquid crystal compound that forms the smectic B phase, the smectic F phase, or the smectic I phase. If the liquid crystal layer 11 formed of the polymerizable liquid crystal compound is such a high-order smectic phase, a region with higher polarization performance can be formed in the liquid crystal layer 11. In addition, such a region with a higher polarization performance obtains a Bragg wave peak derived from a hexagonal phase or a crystal having a higher order structure in an X-ray diffraction measurement. The Bragg peaks are derived from the molecular structure of the periodic structure of the peaks, and a film with a periodic interval of 3 to 6 Å can be obtained. In the polarizing film 1 of this embodiment, the liquid crystal layer 11 contains a polymer in which a polymerizable liquid crystal compound is polymerized in a smectic phase state, and thus, for example, it is possible to impart higher polarizing characteristics to the first region 11a, so it is preferable.

For example, it can be confirmed whether the polymerizable liquid crystal compound shows a nematic liquid crystal phase or a smectic liquid crystal phase by the following method. After the polarizing film-forming composition is coated on the substrate to form a coating film, the solvent contained in the coating film is removed by performing a heat treatment under conditions in which the polymerizable liquid crystal compound does not polymerize. Then, by using texture observation, X-ray diffraction measurement, or differential scanning calorimetry using a polarizing microscope, the liquid crystal expressed by heating a coating film formed on a substrate to an isotropic phase temperature and slowly cooling it Phase check.

Specific examples of such a polymerizable liquid crystal compound include a compound represented by the following formula (A) (hereinafter sometimes referred to as a compound (A)).
U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (A)
[In the formula (A), X ¹ , X ² and X ³ each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the divalent aromatic group or the divalent alicyclic group The hydrogen atom contained in the hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group. The carbon atom of the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom; at least one of X ¹ , X ^2, and X ³ may have a substituent. 1,4-phenylene or cyclohexane-1,4-diyl which may have a substituent;
Y ¹ , Y ² , W ¹ and W ² are independently a single bond or a divalent linking group;
V ¹ and V ² are each independently an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ -constituting the alkanediyl group may be substituted with -O-, -S-, or NH-;
U ¹ and U ² each independently represent a polymerizable group or a hydrogen atom, and at least one is a polymerizable group].

In the compound (A), at least one of X ¹ , X ² and X ³ is 1,4-phenylene which may have a substituent or cyclohexane-1,4-diyl which may have a substituent. In particular, X ¹ and X ^{3 are} preferably cyclohexane-1,4-diyl which may have a substituent, and the cyclohexane-1,4-diyl is further preferably trans-cyclohexane-1,4 -Two bases. When a structure containing trans-cyclohexane-1,4-diyl group is used, there is a tendency that the smectic liquid crystal property is easily expressed. Examples of the optionally substituted 1,4-phenylene group and cyclohexane-1,4-diyl group which may have a substituent include carbons such as methyl, ethyl, or butyl. A halogen atom such as an alkyl group having a number of 1 to 4, a cyano group, a chlorine atom, or a fluorine atom. It is preferably unsubstituted.

Y ¹ and Y ^{2 are} preferably single bonds, -CH ₂ CH _2- , -CH ₂ O-, -COO-, -OCO-, -N = N-, -CR ^a = CR ^b -,- C≡C- or CR ^a = N-, and R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y ¹ and Y ^{2 are more} preferably -CH ₂ CH _2- , -COO-, -OCO-, or a single bond, and in the case where X ¹ , X ² and X ³ do not contain cyclohexane-1,4-diyl. In this case, Y ¹ and Y ² are more preferably different bonding methods. When Y ¹ and Y ² are different bonding methods, there is a tendency that smectic liquid crystal properties are easily expressed.

W ¹ and W ^{2 are} preferably a single bond, -O-, -S-, -COO-, or OCO-, and more preferably a single bond or -O-, which are independent of each other.

Examples of the alkanediyl group having 1 to 20 carbon atoms represented by V ¹ and V ² include methylene, ethylene, propane-1,3-diyl, butane-1,3-diyl, and butane. Alkane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane Alkane-1,10-diyl, tetradecane-1,14-diyl or eicosane-1,20-diyl, etc. V ¹ and V ^{2 are} preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably a straight-chain alkanediyl group having 6 to 12 carbon atoms. By using a linear alkylene group having 6 to 12 carbon atoms, crystallinity is improved, and it is easy to express smectic liquid crystallinity.

Examples of the optionally substituted alkanediyl group having 1 to 20 carbon atoms which may have a substituent include a cyano group, a halogen atom such as a chlorine atom, a fluorine atom, and the like. The alkanediyl group is preferably unsubstituted, and more preferably It is an unsubstituted and linear alkanediyl.

U ¹ and U ^{2 are} preferably both polymerizable groups, and more preferably both are photopolymerizable groups. A polymerizable liquid crystal compound having a photopolymerizable group is advantageous in terms of being able to polymerize at a lower temperature than a thermally polymerizable group, and thereby forming a polymerizable liquid crystal compound in a state with a higher degree of order.

The polymerizable groups represented by 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, a propenyloxy group, a methacryloxy group, an ethylene oxide group, Oxetanyl and the like. Among them, acryloxy, methacryloxy, ethyleneoxy, ethylene oxide, or oxetanyl is preferred, and methacryloxy or acryloxy is more preferred.

Examples of such a polymerizable liquid crystal compound include the following.

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4]

Among the above-exemplified compounds, it is preferably selected from the group consisting of formula (1-2), formula (1-3), formula (1-4), formula (1-6), formula (1-7), formula (1- 8) At least one of the group consisting of compounds represented by formula (1-13), formula (1-14) and formula (1-15).

The exemplified compound (A) can be used in the liquid crystal layer 11 alone or in combination. When two or more kinds of polymerizable liquid crystal compounds are combined, it is preferred that at least one kind is a compound (A), and more preferably two or more kinds are a compound (A). By combining two or more polymerizable liquid crystal compounds, liquid crystallinity may be temporarily maintained even at a temperature below the liquid crystal-crystal phase transition temperature. When the two polymerizable liquid crystal compounds are combined, the mixing ratio is usually 1:99 to 50:50, preferably 5:95 to 50:50, and further preferably 10:90 to 50:50.

Compound (A) can be produced, for example, by a known method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

The content of the polymerizable liquid crystal compound in the liquid crystal layer 11 is usually 50 to 99.5 parts by mass, preferably 60 to 99 parts by mass, and more preferably 70 to 98 parts by mass with respect to 100 parts by mass of the solid component of the liquid crystal layer 11. It is more preferably 80 to 97 parts by mass. When the content of the polymerizable liquid crystal compound is within the above range, there is a tendency that the alignment property becomes high. Here, the solid component refers to the total amount of components after the solvent is removed from the polarizing layer-forming composition described below.

(Dichroic pigment)
The so-called dichroic pigment refers to a pigment having different properties in the absorbance in the long axis direction of the molecule and the absorbance in the short axis direction. A dichroic pigment is a pigment which is aligned with a liquid crystal compound to exhibit dichroism. The dichroic pigment itself may have polymerizability or liquid crystallinity. As a dichroic pigment, it is preferable that it has the characteristic of absorbing visible light, and it is more preferable that it has the absorption maximum wavelength ((lambda) _MAX ) in the range of 380-680 nm. Examples of such dichroic pigments include acridine pigments, osmium pigments, cyanine pigments, naphthalene pigments, azo pigments, and anthraquinone pigments. Among these, azo pigments are preferred. Examples of the azo pigment include a monoazo pigment, a disazo pigment, a triazo pigment, a tetraazo pigment, and a triazo pigment, and a diazo pigment or a triazo pigment is preferred. The dichroic pigment may be used alone or in combination of two or more. In order to obtain absorption in the entire visible light region, it is preferable to combine three or more dichroic pigments, and it is more preferable to combine three or more azo pigments.

Examples of the azo pigment include a compound represented by formula (I) (hereinafter sometimes referred to as "compound (I)")
T ¹ -A ¹ (-N = NA ² ) _p -N = NA ³ -T ² (I)
[In formula (I), A ¹ , A ² and A ³ independently of each other represent a 1,4-phenylene group, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic ring which may have a substituent T ¹ and T ² are independent of each other as an electron withdrawing group or an electron pushing group, and are located at a position substantially 180 ° with respect to the azo bond plane; p represents an integer of 0 to 4; when p is 2 or more, Each A ² may be the same as or different from each other; in a range showing absorption in the visible light range, the -N = N- bond may be replaced by -C = C-, -COO-, -NHCO-, or -N = CH- key].

Examples of the substituents arbitrarily possessed by 1,4-phenylene, naphthalene-1,4-diyl, and divalent heterocyclic group among A ¹ , A ² and A ³ include: methyl, ethyl or Alkyl groups having 1 to 4 carbons such as butyl; alkoxy groups having 1 to 4 carbons such as methoxy, ethoxy or butoxy; fluorinated alkyl groups having 1 to 4 carbons such as trifluoromethyl; Cyano group; nitro group; halogen atom such as chlorine atom, fluorine atom; substituted or unsubstituted amine group such as amine group, diethylamine group and pyrrolidinyl group (the so-called substituted amine group means having 1 or 2 An amino group of an alkyl group having 1 to 6 carbon atoms, or an amino group of 2 substituted alkyl groups to form an alkyldiyl group having 2 to 8 carbon atoms; the unsubstituted amino group refers to -NH ₂ ). Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, and a hexyl group. Examples of the alkanediyl group having 2 to 8 carbon atoms include ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, and pentane- 1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl or octane-1,8-diyl, etc. In order to include the compound (I) in a high-order liquid crystal structure such as a smectic liquid crystal, A ¹ , A ² and A ^{3 are} preferably independently unsubstituted, hydrogen substituted with methyl or methoxy 1, 4-phenylene or a divalent heterocyclic group, and p is preferably 0 or 1. Among them, in terms of the simplicity and high performance of molecular synthesis, it is more preferable that p is 1 and at least two of the three structures of A ¹ , A ^2, and A ³ are 1,4-phenylene. .

Examples of the divalent heterocyclic group include a group obtained by removing two hydrogen atoms from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. In the case where A ² is a divalent heterocyclic group, a structure having a molecular bonding angle of substantially 180 ° is preferred, and more specifically, benzothiazole and benzo formed by condensing two 5-membered rings are more preferred. Structure of imidazole and benzoxazole.

T ¹ and T ^{2 are} preferably mutually independent structures that are electron-withdrawing or electron-withdrawing groups, and further preferably T ¹ is an electron-withdrawing group and T ² is an electron-withdrawing group, or T ¹ is an electron-withdrawing group And T ² is an electron withdrawing group. Specifically, T ¹ and T ^{2 are} preferably independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, and a nitro group, each having 1 or 2 carbon atoms having 1 to 2 carbon atoms. An amine group of an alkyl group of 6 or an amine group of two substituted alkyl groups to form an alkanediyl group of 2 to 8 carbon atoms or a trifluoromethyl group, in order to be included in a high order such as a smectic liquid crystal In the liquid crystal structure, a structure having a smaller molecular repulsion volume is necessary, so an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, and one or two carbon numbers are preferred. An amine group of an alkyl group of 1 to 6 or an amine group of an alkyldiyl group having 2 to 8 carbon atoms is bonded to each other by two substituted alkyl groups.

Examples of such an azo pigment include the following.

[Chemical 5]

[Chemical 6]

[In the formulae (2-1) to (2-6), B ¹ to B ²⁰ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group , Substituted or unsubstituted amine groups (the definition of substituted and unsubstituted amine groups is as described above), a chlorine atom or a trifluoromethyl group; and from the viewpoint of obtaining higher polarizing performance In other words, B ² , B ⁶ , B ⁹ , B ¹⁴ , B ¹⁸ , B ^{19 is} preferably a hydrogen atom or a methyl group, and further preferably a hydrogen atom;
n1 to n4 each independently represent an integer of 0 to 3;
When n1 is 2 or more, a plurality of B ² may be the same or different,
When n2 is 2 or more, a plurality of B ⁶ may be the same or different, respectively.
When n3 is 2 or more, a plurality of B ⁹ may be the same or different,
When n4 is 2 or more, a plurality of B ¹⁴ may be the same or different.]

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

[Chemical 7]

[In the formula (2-7), R ¹ to R ⁸ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom;
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms]

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

[Chemical 8]

[In formula (2-8), R ⁹ to R ¹⁵ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom;
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms]

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

[Chemical 9]

[In formula (2-9), R ¹⁶ to R ²³ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom;
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms]

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ^x in formula (2-7), formula (2-8), and formula (2-9) include methyl, ethyl, propyl, and butyl Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolylmethyl group, a xylyl group, a naphthyl group, and the like.

As said cyanine pigment, the compound represented by Formula (2-10) and the compound represented by Formula (2-11) are preferable.

[Chemical 10]

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

[Chemical 11]

n5 represents an integer of 1 to 3]

[Chemical 12]

[In formula (2-11), D ³ and D ⁴ independently represent the bases represented by any one of formulas (2-11a) to (2-11h);
[Chemical 13]

n6 represents an integer of 1 to 3]

As the content rate of the dichroic pigment (a ratio of the total amount when plural types are contained), from the viewpoint of obtaining good light absorption characteristics, the visual sensitivity is corrected in the first region 11a of the liquid crystal layer 11, for example. In a region having a high degree of polarization (Py) of 90% or more, it is usually preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, and more preferably 100 parts by mass of the polymerizable liquid crystal compound. It is preferably 3 to 15 parts by mass. If the content of the dichroic pigment is lower than this range, the light absorption becomes insufficient, and sufficient polarizing performance cannot be obtained. If it exceeds the range, the alignment of the liquid crystal molecules may be hindered. In the second region 11b of the liquid crystal layer 11, in a region with low polarization characteristics where the visual sensitivity correction polarization (Py) is 10% or less, it is usually preferably from 0 to 20 masses relative to 100 parts by mass of the polymerizable liquid crystal compound. Parts, more preferably 0 to 10 parts by mass, and even more preferably 0 to 5 parts by mass.

(Base material layer)
The polarizing film 1 may include a base material layer 13. The base material layer 13 can be used to support the alignment layer 12 or the following polarizing layer 21 when manufacturing the polarizing film 1 as described below, and can also be used to support the liquid crystal layer 11 of the polarizing film 1.

The substrate layer 13 may be a glass substrate or a resin substrate, and is preferably a resin substrate. In addition, in terms of the ability to continuously manufacture the polarizing film 1, the base material layer 13 is more preferably a resin substrate that is rolled up into a long roll-shaped resin substrate. The resin substrate is preferably a substrate having a light-transmitting property capable of transmitting visible light. Here, the term “light-transmitting property” means that the visual sensitivity correction monomer transmittance to light in a wavelength range of 380 to 780 nm is 80% or more.

The thickness of the base material layer 13 is preferably thin in terms of practically operable quality, but if it is too thin, the strength tends to decrease and the workability tends to deteriorate. The thickness of the base material layer 13 is usually 5 μm to 300 μm, and preferably 20 μm to 200 μm. The base material layer 13 may be provided in a peelable manner. For example, after the liquid crystal layer 11 of the polarizing film 1 is bonded to a member constituting a display device or a retardation layer described below, it can be peeled from the polarizing film 1. Thereby, a further thinning effect of the polarizing film 1 can be obtained.

Examples of the resin constituting the resin substrate include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid Esters; polyacrylates; cellulose esters such as triethyl cellulose, diethyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polyfluorene; polyetherfluorene; polyetherketone ; Polyphenylene sulfide and polyphenylene ether.

Examples of commercially available cellulose ester resin substrates include: "Fujitac Film" (manufactured by Fujifilm Corporation); "KC8UX2M", "KC8UY", and "KC4UY" (above, manufactured by Konica Minolta Opto Co., Ltd.) Wait.

Examples of commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "ARTON" (registered trademark) (manufactured by JSR Corporation), and "ZEONOR" (registered trademark) ), "ZEONEX" (registered trademark) (above, made by Japan Zeon Corporation) and "APEL" (registered trademark) (made by Mitsui Chemicals Co., Ltd.). Such a cyclic olefin-based resin can be formed into a resin substrate by a known method such as a solvent casting method and a melt extrusion method. It is also possible to use a resin substrate of a commercially available cyclic olefin-based resin. Examples of commercially available resin substrates for cyclic olefin resins include "S-SINA" (registered trademark), "SCA40" (registered trademark) (above, manufactured by Sekisui Chemical Industry Co., Ltd.), and "ZEONOR FILM" (Registered trademark) (manufactured by Optronics Corporation) and "ARTON FILM" (registered trademark) (manufactured by JSR Corporation).

The base material layer 13 may have a single-layer structure or a multilayer structure of two or more layers. When the base material layer 13 has a multilayer structure, each layer may be formed of the same material or may be formed of materials different from each other.

Moreover, the base material layer 13 may have a 1/4 wavelength plate function. By making the base material layer 13 have a 1/4 wavelength plate function, and by combining the base material layer 13 and the liquid crystal layer 11, a polarizing film having the function of a circular polarizing plate can be obtained. Thereby, a circular polarizing plate can be obtained even if the retardation layer having a 1/4 wavelength plate function is not bonded to the polarizing film 1 except for the base material layer 13. In the case where the base material layer 13 has a multilayer structure, the liquid crystal layer 11 can be laminated on a substrate having a layer having a function of a 1/2 wavelength plate and a layer having a function of a 1/4 wavelength plate. The layer side of the 1/2 wavelength plate functions to obtain a circularly polarizing plate. Alternatively, in the case where the base material layer 13 has a multilayer structure, it is also possible to obtain a circle by using a layer having a function of a quarter-wavelength plate having inverse wavelength dispersion and a layer having a positive C-plate function. Polarizer.

(Alignment layer)
The polarizing film 1 may have an alignment layer 12 on the substrate layer 13, and the alignment layer 12 is disposed between the substrate layer 13 and the liquid crystal layer 11. The alignment layer 12 may have an alignment restricting force that aligns the liquid crystal compound in the liquid crystal layer 11 laminated thereon in a desired direction.

The alignment layer 12 facilitates liquid crystal alignment of a liquid crystal compound. The state of liquid crystal alignment, such as horizontal alignment, vertical alignment, mixed alignment, and oblique alignment, varies depending on the properties of the alignment layer 12 and the liquid crystal compound, and the combination thereof can be arbitrarily selected. For example, if the alignment layer 12 is a material exhibiting horizontal alignment as an alignment restricting force, the liquid crystal compound may form a horizontal alignment or a hybrid alignment. If the alignment layer 12 is a material exhibiting a vertical alignment, the liquid crystal compound may form a vertical alignment or an oblique alignment. Expressions such as horizontal and vertical indicate the direction of the long axis of the liquid crystal compound aligned when the plane of the polarizing film 1 is used as a reference. For example, the so-called vertical alignment refers to the long axis of the polymerizable liquid crystal having alignment in the vertical direction with respect to the plane of the polarizing film 1. The vertical here means 90 ° ± 20 ° with respect to the plane of the polarizing film 1. The polarizing film 1 preferably has the polarizing characteristics of the plane of the polarizing film 1, so the alignment layer 12 is preferably formed using a material that exhibits horizontal alignment.

As the alignment limiting force of the alignment layer 12, in the case where the alignment layer 12 is formed of an alignment polymer, it can be arbitrarily adjusted by the surface state or the friction conditions. In the case of the photo-alignment polymer, it can be borrowed. It is arbitrarily adjusted according to polarized light irradiation conditions and the like. In addition, the liquid crystal alignment can be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

The thickness of the alignment layer 12 is usually 10 nm to 5000 nm, preferably 10 nm to 1000 nm, and more preferably 30 nm to 300 nm. The alignment layer 12 formed between the base material layer 13 and the liquid crystal layer 11 is preferably insoluble to a solvent used in forming the liquid crystal layer 11 on the alignment layer 12 and has a heat treatment for removing the solvent or alignment of the liquid crystal. Of heat resistance.

Examples of the alignment layer 12 include an alignment film containing an alignment polymer, a photo-alignment film, and a groove alignment film. In the case where the base material layer 13 is a roll-out of a long resin substrate having a roll shape, the alignment layer 12 is preferably a photo-alignment film in terms of easily controlling its alignment direction.

Examples of the alignment polymer include polyamines or gelatins having a amine bond in the molecule, polyimide having a iminium bond in the molecule, polyamic acid as a hydrolyzate thereof, polyvinyl alcohol, Alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethylenimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid or polyacrylates, etc. Among these, polyvinyl alcohol is preferred. These alignment polymers may be used alone or in combination of two or more.

An alignment film containing an alignment polymer can generally be obtained by applying a composition (hereinafter sometimes referred to as "alignment polymer composition") in which a alignment polymer is dissolved in a solvent, to a substrate layer. 13. The solvent is removed, or the alignment polymer composition is applied to the base material layer 13, the solvent is removed, and rubbing is performed (friction method).

Examples of the solvent used in the alignment polymer composition include water; alcohols such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cyrus, butyl cyrus, or propylene glycol monomethyl ether Solvents; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, or ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone , Ketone solvents such as cyclohexanone, methylpentanone or methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane or heptane; aromatic hydrocarbon solvents such as toluene or xylene; nitrile solvents such as acetonitrile; tetrahydrofuran or Ether solvents such as dimethoxyethane; chlorine-substituted hydrocarbon solvents such as chloroform or chlorobenzene. These solvents may be used alone or in combination of two or more.

As long as the content of the alignment polymer in the alignment polymer composition is in a range in which the alignment polymer can be completely dissolved in the solvent, it is preferably 0.1 to 20% by mass in terms of solid content conversion with respect to the solution. It is preferably 0.1 to 10% by mass.

As the alignment polymer composition, a commercially available alignment film material can be directly used. 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).

Examples of the method for applying the alignment polymer composition to the substrate layer 13 include a spin coating method, an extrusion coating method, a gravure coating method, a die coating method, a rod coating method, or a dressing. A well-known method such as a coating method such as a printing method or a printing method such as a flexographic method. When the polarizing film 1 is manufactured by a roll-to-roll continuous manufacturing method, the coating method may generally adopt a printing method such as a gravure coating method, a die coating method, or a flexographic method. .

By removing the solvent contained in the alignment polymer composition, a dry film of the alignment polymer is formed. Examples of the method for removing the solvent include a natural drying method, a ventilation drying method, a heating drying method, and a reduced-pressure drying method. Thereafter, the dry coating film can be brought into contact with a rotating friction roller wound with a friction cloth to form the alignment layer 12.

A photo-alignment film is generally obtained by applying a composition (hereinafter sometimes referred to as a "photo-alignment film-forming composition") containing a polymer or monomer having a photoreactive group and a solvent to a substrate. The layer 13 forms a coating layer for an alignment layer, and the coating layer for an alignment layer is irradiated with polarized light (preferably polarized UV (ultraviolet)). The light alignment film is more preferable in that the direction of the alignment restriction force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

The photoreactive group refers to a group that generates liquid crystal alignment ability by irradiating light. Specifically, it is a photoresponder that becomes the origin of the alignment ability of a liquid crystal by irradiating light to generate, for example, molecular orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodecomposition reaction. Among these photoreactive groups, those having excellent alignment properties are preferably those that cause a dimerization reaction or a photocrosslinking reaction. As the photoreactive group capable of generating the above reaction, it is preferred to have an unsaturated bond, especially a double bond, more preferably a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), a nitrogen-nitrogen double bond (N = N bond), and a carbon-oxygen double bond (C = O bond).

Examples of the photoreactive group having a C = C bond include a vinyl group, a polyalkenyl group, a fluorenyl group, an oxazolyl group, a stilbazonium group, a chalcone group, and a cinnamyl group. From the viewpoint of easily controlling the reactivity or the expression of the alignment limiting force at the time of photo-alignment, a chalcone group or a cinnamyl group is preferred. Examples of the photoreactive group having a C = N bond include a group having a structure such as an aromatic Schiff base or an aromatic fluorene. Examples of the photoreactive group having an N = N bond include azophenyl, azonaphthyl, aromatic heterocyclic azo, diazo, or methylamino, or the like based on azobenzene oxide. Structurer. 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 aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, or a halogenated alkyl group.

As a solvent of the composition for forming a photo-alignment film, it is preferable to dissolve a polymer and monomer having a photoreactive group. Examples of the solvent include solvents listed as a solvent of the above-mentioned alignment polymer composition. .

The content of the polymer or monomer having a photoreactive group in the composition for forming a photoalignment film can be appropriately determined according to the type of the polymer or monomer having a photoreactive group or the thickness of the photoalignment film to be manufactured. The adjustment is preferably 0.2% by mass or more, and particularly preferably in the range of 0.3 to 10% by mass. In addition, a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer may be contained within a range that does not significantly impair the characteristics of the photo-alignment film.

Examples of the method for applying the composition for forming a photo-alignment film to the substrate layer 13 include the same method as the method for applying the alignment polymer composition to the substrate layer 13 described above. Examples of the method for removing the solvent from the applied photo-alignment film-forming composition include the same method as the method for removing the solvent from the alignment polymer composition.

The polarized light irradiation can be performed directly from the dry film from which the solvent is removed from the photo-alignment film-forming composition coated on the substrate layer 13, or the polarized light can be irradiated to the dry film through the polarized light of the substrate layer 13. The material layer 13 is performed. The polarized light used for polarized light irradiation is particularly preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably a wavelength region in which a polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in a range of 250 to 400 nm is particularly preferred. Examples of the light source used in polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, KrF, ArF and other ultraviolet lasers, and more preferably high-pressure mercury lamps, ultra-high pressure mercury lamps, or metal halides. light. These lamps are preferred due to the greater luminous intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by irradiating light from a light source through an appropriate polarizing element. As this polarizing element, a polarizing filter, a polarizing element such as Glan-Thompson, Glan-Taylor, or a wire grid type polarizing element can be used.

In addition, when rubbing or polarizing light is irradiated, a plurality of regions (patterns) with different directions of liquid crystal alignment may be formed if they are shielded.

The groove alignment film is a film having a concave-convex pattern or a plurality of grooves (grooves) on the surface of the film. When the liquid crystal molecules are placed in a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction of the grooves.

Examples of the method for obtaining the groove alignment film include a method for forming a concave-convex pattern by exposing the surface of the photosensitive polyimide film with an exposure mask through a slit having a pattern shape, and then developing and rinsing it. ; A method of forming a UV-curable resin layer before hardening on a plate-shaped master having grooves on the surface, and moving the resin layer to a base material for hardening; pressing a roller-shaped master having a plurality of grooves against the formation A method of forming unevenness on a UV-curable resin film before curing on a substrate, and thereafter curing. Specific examples include the methods described in Japanese Patent Laid-Open No. 6-34976 and Japanese Patent Laid-Open No. 2011-242743.

In order to obtain a less misaligned alignment, the width of the convex portion of the trench alignment film is preferably 0.05 μm to 5 μm, the width of the concave portion is preferably 0.1 μm to 5 μm, and the depth of the step difference of the unevenness is preferably 2 μm. Hereinafter, it is preferably 0.01 μm to 1 μm.

(Other layers)
The polarizing film 1 may include layers other than the base material layer 13 and the alignment layer 12. For example, a surface protection layer for protecting the surface of the liquid crystal layer 11 or the like may be provided on the surface of the liquid crystal layer 11 opposite to the base material layer 13. In the case of using the release base material layer 13, a surface protective layer may be provided on the surface of the liquid crystal layer 11 on the side of the release base material layer 13. The surface protective layer may have a single-layer structure or a multilayer structure. When the surface protective layer has a multilayer structure, each layer may be formed of the same material or may be formed of materials different from each other.

＜ Circular polarizing plate ＞
2 (a) to (c) are schematic cross-sectional views each showing an example of a circular polarizing plate of the present invention. The polarizing film 1 shown in FIG. 1 (b) can be formed into a circular polarizing plate 5a, 5b as shown in FIGS. 2 (a) and (b) by stacking a retardation layer 15 having a 1/4 wavelength plate function. The retardation layer 15 may be laminated on the liquid crystal layer 11 side of the polarizing film 1 (FIG. 2 (a)), or may be laminated on the substrate layer 13 side (FIG. 2 (b)). In addition, the circularly polarizing plate 5a shown in FIG. 2 (a) may be used as the circularly polarizing plate 5c (FIG. 2 (c)), and the alignment layer may be used as the circularly polarizing plate 5c. 12 is peeled together with the base material layer 13.

The circularly polarizing plate may be formed by laminating a polarizing film 1 and a retardation having a multilayer structure. In this case, as the retardation layer having a multilayer structure, a retardation layer having a layer having a function of a 1/2 wavelength plate and a layer having a function of a 1/4 wavelength plate can be used. The layer side having the function of a 1/2 wavelength plate and the polarizing film 1 are laminated to form a circular polarizing plate. Alternatively, a circularly polarizing plate can be obtained by using a retardation layer laminated with a 1/4 wavelength plate function having inverse wavelength dispersion and a layer having a positive C plate function as a retardation layer of a multilayer structure.

In addition, a circular polarizing plate can be produced by using a function as a retardation layer as the base material layer 13 of the polarizing film 1 and further laminating the retardation layer. In this case, the function of the base layer 13 and the retardation layer as a retardation layer may be selected according to the laminated position of the base layer 13 and the retardation layer in the circular polarizing plate.

The polarizing film and the retardation layer may be laminated via an adhesive layer using a known adhesive or adhesive.

<Method for Manufacturing Polarizing Film (First Manufacturing Method)>
3 (a) to (d) are schematic cross-sectional views showing the layer structure obtained in each step of the manufacturing steps of the polarizing film 1 shown in FIG. 1 (b). The first manufacturing method of the polarizing film 1 has the following steps:
The preparation step is to prepare a build-up film 62 having a polarizing layer 21 containing a liquid crystal compound and a dichroic pigment on at least one side of the substrate layer 13 (FIG. 3 (b)); and a liquid contact step, that is, by A part of the polarizing layer 21 of the laminated film 62 is brought into contact with a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer 21, and the content of the dichroic pigment is reduced in a part of the region of the polarizing layer 21.

The liquid contact step has the following steps:
The protective layer lamination step is to obtain a protective layer with a protective layer 35 formed by laminating a protective layer 35 on the polarizing layer 21 of the laminating film 62 with a covering area 35 a for covering the polarizing layer 21 and an exposed area 35 b for exposing the polarizing layer 21. Laminated film 63 (Fig. 3 (c));
The decoloring step is to reduce the dichroism in a part of the polarizing layer 21 by bringing the laminated film 63 with a protective layer into contact with a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer 21. A decoloring laminated film 64 (FIG. 3 (d)) with a pigment content rate; and a peeling step, by peeling the protective layer 35 from the decolorized laminated film 64, whereby the polarizing film 1 shown in FIG. 1 (b) can be manufactured.

(Preparation steps)
The laminated film 62 prepared in the preparation step is not particularly limited as long as it has a polarizing layer 21 on at least one side of the base material layer 13, and it is preferable that the multilayer film 62 is provided on the base material layer 13 as shown in FIG. 3 (b). The alignment layer 12 and the polarizing layer 21 are laminated in this order. Such a laminated film 62 can be manufactured through the following steps: an alignment layer forming step, in which an alignment layer-forming composition is coated on one surface of the substrate layer 13 to form an alignment layer 12 to obtain a substrate layer 61 with an alignment layer ( FIG. 3 (a)); and a polarizing layer forming step, that is, a polarizing layer-forming composition is formed by applying a composition for forming a polarizing layer on the side of the base material layer 61 with the alignment layer on which the alignment layer 12 is formed.

In the alignment layer forming step, the base material layer 13 may be subjected to a surface treatment before the composition for forming the alignment layer is applied. Examples of the surface treatment method include a corona treatment, a plasma treatment, a laser treatment, an ozone treatment, a saponification treatment, a flame treatment, a coating treatment of a coupling agent, and a primer treatment. As the composition for forming an alignment layer, the above-mentioned alignment polymer composition, a composition for forming a photo-alignment film, a composition containing a resin material for forming a groove alignment film, and the like can be used. The method for forming an alignment layer using each composition is also as described above. For example, in a case where the composition for forming an alignment layer contains a photo-alignable polymer, the alignment layer forming step may be performed by applying polarized light to a coating layer for an alignment layer formed by applying the composition for forming an alignment layer. An alignment layer having an alignment restricting force in a specific direction.

The composition for forming a polarizing layer is a composition containing a liquid crystal compound and a dichroic dye, and preferably contains a solvent and a polymerization initiator, and may contain a sensitizer, a polymerization inhibitor, a leveling agent, a reactive additive, and the like. As the liquid crystal compound and the dichroic dye, those described above can be used, and as the solvent, polymerization initiator, sensitizer, polymerization inhibitor, leveling agent, and reactive additive, the following can be used.

Examples of a method for applying the composition for forming a polarizing layer include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a capillary (CAP) coating method, a slit coating method, and a micro gravure. Coating method, die coating method, inkjet method, and the like. In addition, a method of coating using a coating machine such as a dip coater, a bar coater, or a spin coater can also be mentioned. Among them, in the case of continuous coating in a roll-to-roll form, a coating method using a microgravure coating method, an inkjet method, a slit coating method, and a die coating method is preferably applied to glass. In the case of a single-piece substrate, a spin coating method having high uniformity is preferred. In the case of coating in a roll-to-roll format, the alignment layer 12 may be formed by applying an alignment film-forming composition or the like on the substrate layer 13, and further, a polarizing layer may be continuously applied on the obtained alignment layer 12. combination.

When the polarizing layer 21 is formed by applying the polarizing layer-forming composition, the solvent is removed from the applied polarizing layer-forming composition to form a polarizing layer coating layer. As a method of removing the solvent, the same method as the method of removing the solvent from the self-aligning polymer composition can be used, and examples thereof include a method of natural drying, air-drying, heat-drying, reduced-pressure drying, and combinations thereof. Among them, natural drying or heat drying is preferred. The drying temperature is preferably in the range of 0 to 200 ° C, more preferably in the range of 20 to 150 ° C, and even more preferably in the range of 50 to 130 ° C. The drying time is preferably 10 seconds to 10 minutes, and more preferably 30 seconds to 5 minutes.

When the liquid crystal compound contained in the polarizing layer-forming composition is a polymerizable liquid crystal compound, it is preferable to irradiate the coating layer for a polarizing layer formed in the polarizing layer forming step with active energy rays to polymerize the liquid crystal compound. The photopolymerization is performed to form a polarizing layer 21 as a polymer layer of a polymerizable liquid crystal compound. The active energy ray to be irradiated depends on the type of the polymerizable liquid crystal compound (especially the type of the photopolymerizable functional group of the polymerizable liquid crystal compound) contained in the coating layer for the polarizing layer, and In the case, it is appropriately selected according to the type and amount of the photopolymerization initiator. Specifically, one or more kinds of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays can be mentioned. Among them, in terms of the ease of controlling the progress of the polymerization reaction and the point that a wide range of users in the field can be used as the photopolymerization device, ultraviolet light is preferred, and photopolymerization by ultraviolet light is preferred. Select the type of polymerizable liquid crystal compound.

Examples of light sources of active energy rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten filament lamps, gallium lamps, excimer lasers, and emission wavelength ranges. LED (Light-emitting diode) light source of 380 ～ 440 nm light, chemical lamp, black light lamp, microwave excited mercury lamp, metal halide lamp, etc.

The irradiation intensity of the active energy ray is usually 10 mW / cm ² to 3000 mW / cm ² . The irradiation intensity of the active energy ray is preferably an intensity in a wavelength region effective for activation of the cationic polymerization initiator or the radical polymerization initiator. The irradiation time of the active energy ray is usually from 0.1 seconds to 10 minutes, preferably from 0.1 seconds to 5 minutes, more preferably from 0.1 seconds to 3 minutes, and even more preferably from 0.1 seconds to 1 minute. If the active energy ray is irradiated once or multiple times, the cumulative light amount is 10 mJ / cm ² to 3000 mJ / cm ² , preferably 50 mJ / cm ² to 2,000 mJ / cm ² , more It is preferably 100 mJ / cm ² to 1000 mJ / cm ² . When the cumulative light amount is below this range, the curing of the polymerizable liquid crystal compound may be insufficient, and a good transferability may not be obtained. Conversely, when the cumulative light amount is above the range, there may be a case where the polarizing layer is colored.

(Solvent)
The composition for forming a polarizing layer may contain a solvent. Generally, the viscosity of a polymerizable liquid crystal compound is high. Therefore, when a polymerizable liquid crystal compound is used as the liquid crystal compound, by using a composition for forming a polarizing layer containing a solvent, application can be facilitated, and as a result, polarized light is easily formed. Floor. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound and the dichroic dye, and more preferably a solvent that is inert to the polymerization reaction of the polymerizable liquid crystal compound.

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, or propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and ethylene glycol Ester solvents such as alcohol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate or ethyl lactate; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone or methyl Ketone solvents such as isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane or heptane; aromatic hydrocarbon solvents such as toluene or xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran or dimethoxyethane; chloroform or Chlorine-containing solvents such as chlorobenzene; amines such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidone, etc. Solvents, etc. These solvents may be used alone or in combination of two or more.

The content of the solvent contained in the composition for forming a polarizing layer is preferably 50 to 98% by mass based on the total amount of the composition for forming a polarizing layer. In other words, the content of the solid component in the polarizing layer-forming composition is preferably 2 to 50% by mass. When the content of the solid component is 50% by mass or less, the viscosity of the composition for forming a polarizing layer is lowered, so that the thickness of the polarizing layer 21 becomes substantially uniform, and unevenness tends not to occur in the polarizing layer 21. The content of the solid component can be determined in consideration of the thickness of the polarizing layer 21 to be manufactured.

(Polymerization initiator)
The composition for forming a polarizing layer may contain a polymerization initiator. The polymerization initiator can be used when a polymerizable liquid crystal compound is used as the liquid crystal compound, and is a compound that can initiate a polymerization reaction of the polymerizable liquid crystal compound and the like. As the polymerization initiator, a photopolymerization initiator that generates an active radical by the action of light is preferred from the viewpoint of not depending on the phase state of the thermotropic liquid crystal.

Examples of the polymerization initiator include a benzoin compound, a benzophenone compound, an alkyl phenone compound, a fluorenylphosphine oxide compound, a three compound, a sulfonium salt, or a sulfonium salt.

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

Examples of the benzophenone compound include benzophenone, methyl o-benzoyl benzoate, 4-phenylbenzophenone, and 4-benzophenyl-4'-methyldiphenylsulfide. Ether, 3,3 ', 4,4'-tetrakis (third butylcarbonyl) benzophenone and 2,4,6-trimethylbenzophenone.

Examples of the alkyl phenone compound include diethoxyacetophenone, 2-methyl-2-olinyl-1- (4-methylthiophenyl) propane-1-one, and 2-benzyl 2-dimethylamino-1- (4-olinylphenyl) butane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1,2-diphenyl -2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1- [4- (2-hydroxyethoxy) phenyl] propane-1-one, 1- An oligomer of hydroxycyclohexylphenyl ketone or 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1-one, and the like.

Examples of the fluorenylphosphine oxide compounds include 2,4,6-trimethylbenzylfluorenyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzylfluorenyl) phenylphosphine oxide. .

Examples of the three compounds include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-tri, 2,4-bis (trichloromethyl) ) -6- (4-methoxynaphthyl) -1,3,5-tri, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3 , 5-tri, 2,4-bis (trichloromethyl) -6- [2- (5-methylfuran-2-yl) vinyl] -1,3,5-tri, 2,4-bis (Trichloromethyl) -6- [2- (furan-2-yl) vinyl] -1,3,5-tri, 2,4-bis (trichloromethyl) -6- [2- (4 -Diethylamino-2-methylphenyl) vinyl] -1,3,5-tri or 2,4-bis (trichloromethyl) -6- [2- (3,4-dimethoxy Phenyl) vinyl] -1,3,5-three.

Commercially available polymerization initiators can also be used. Examples of commercially available polymerization initiators include: Irgacure (registered trademark) 907, 184, 651, 819, 250, 369, 379, 127, 754, OXE01, OXE02, or OXE03 (made by Ciba Specialty Chemicals Co., Ltd.); Seikuol (registered trademark) BZ, Z or BEE (made by Seiko Chemical Co., Ltd.); kayacure (registered trademark) BP100 or UVI-6992 (made by Dow Chemical Co., Ltd.); Adeka Optomer SP-152, N-1717, N- 1919, SP-170, Adeka arkls NCI-831, Adeka arkls NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A or TAZ-PP (manufactured by Japan Nihon SiberHegner Co., Ltd.); TAZ-104 (Sanwa Chemical Co., Ltd. Co., Ltd.) and so on. One type of polymerization initiator may be used in the polarizing layer-forming composition, or two or more types of polymerization initiators may be mixed and used depending on the light source of light.

The content of the polymerization initiator in the polarizing layer-forming composition can be appropriately adjusted according to the type or amount of the polymerizable liquid crystal compound, and it is usually 0.1 to 30 parts by mass based on 100 parts by mass of the polymerizable liquid crystal compound. Preferably it is 0.5-10 mass parts, More preferably, it is 0.5-8 mass parts. When the content of the polymerization initiator is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

(Sensitizer)
The composition for forming a polarizing layer may contain a sensitizer. The sensitizer is preferably used when a polymerizable liquid crystal compound is used as the liquid crystal compound, and when a polymerizable liquid crystal compound having a photopolymerizable group is used, the sensitizer is preferably a photosensitizer. Examples of the sensitizer include ketones and 9-oxysulfur Isoketone compounds (e.g. 2,4-diethyl-9-oxosulfur , 2-isopropyl-9-oxysulfur Etc.); anthracene compounds such as anthracene and alkoxy-containing anthracene (such as dibutoxyanthracene, etc.); phenanthrene or rubrene.

When the composition for polarizing layer formation contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for polarizing layer formation can be further promoted. The used amount of the sensitizer is 100 parts by mass with respect to the content of the polymerizable liquid crystal compound, preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and still more preferably 0.5 to 3 parts by mass.

(Polymerization inhibitor)
From the viewpoint of stably proceeding the polymerization reaction, the composition for forming a polarizing layer may contain a polymerization inhibitor. The polymerization inhibitor can be preferably used when a polymerizable liquid crystal compound is used as the liquid crystal compound. The polymerization inhibitor can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.

Examples of the polymerization inhibitor include hydroquinone, alkoxy-containing hydroquinone, alkoxy-containing catechol (for example, butylcatechol, etc.), catechol, 2 , 2,6,6-tetramethyl-1-piperidinyloxy radicals and other free radical scavengers; thiophenols; β-naphthylamines or β-naphthols.

When the composition for polarizing layer formation contains a polymerization inhibitor, the content of the polymerization inhibitor relative to the content of the polymerizable liquid crystal compound is 100 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, It is more preferably 0.5 to 3 parts by mass. When the content of the polymerization inhibitor is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

(Leveling agent)
The composition for forming a polarizing layer may contain a leveling agent. The leveling agent refers to an additive having the function of adjusting the fluidity of the composition and making the film obtained by coating the composition flatter, and examples thereof include organically modified silicone oil type, polyacrylate type, or Perfluoroalkyl-based leveling agent. Specific examples: DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all of which are manufactured by Dow Corning Toray (stock)), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all above manufactured by Shin-Etsu Chemical Industry Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all above manufactured by Momentive Advanced Materials Japan Co., Ltd.) , Fluorinert (registered trademark) FC-72, fluorinert FC-40, fluorinert FC-43, fluorinert FC-3283 (all of which are manufactured by Sumitomo 3M (stock)), MEGAFAC (registered trademark) R-08, MEGAFAC R-30, MEGAFAC R-90, MEGAFAC F-410, MEGAFAC F-411, MEGAFAC F-443, MEGAFAC F-445, MEGAFAC F-470, MEGAFAC F-477, MEGAFAC F-479, MEGAFAC F-482, MEGAFAC F-483 ( All of the above are manufactured by DIC (stock), Eftop (brand name) EF301, Eftop EF303, Eftop EF351, Eftop EF352 (all of the above are manufactured by Mitsubishi Electronic Materials Corporation), Surflon (registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, S urflon SC-105, KH-40, SA-100 (all of which are manufactured by AGC Seimi Chemical (stock)), trade name E1830, trade name E5844 (made by Daikin Institute of Precision Chemistry (stock)), BM-1000, BM -1100, BYK-352, BYK-353 or BYK-361N (all are trade names: manufactured by BM Chemie) and the like. Among them, a polyacrylate-based leveling agent or a perfluoroalkyl-based leveling agent is preferred.

When the composition for forming a polarizing layer contains a leveling agent, it is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3, with respect to 100 parts by mass of the content of the liquid crystal compound. Parts by mass. When the content of the leveling agent is within the above range, there is a tendency that the liquid crystal compound is easily aligned horizontally, and the obtained polarizing layer tends to be smoother. When the content of the leveling agent with respect to the liquid crystal compound exceeds the above range, there is a tendency that unevenness tends to occur in the obtained polarizing layer. The composition for forming a polarizing layer may contain two or more leveling agents.

(Reactive additive)
The polarizing layer-forming composition may contain a reactive additive. The reactive additive is preferably one having a carbon-carbon unsaturated bond and an active hydrogen reactive group in its molecule. The "active hydrogen-reactive group" herein refers to a group that is reactive with a group having active hydrogen, such as a carboxyl group (-COOH), a hydroxyl group (-OH), and an amine group (-NH ₂ ), and its representative example It is a glycidyl group, an oxazoline group, a carbodiimide group, an aziridinyl group, a fluorenimine group, an isocyanate group, a thioisocyanate group, a maleic anhydride group, and the like. The number of carbon-carbon unsaturated bonds or active hydrogen reactive groups possessed by the reactive additive is usually 1 to 20, preferably 1 to 10, respectively.

It is preferred that at least two active hydrogen reactive groups are present in the reactive additive. In this case, the plurality of active hydrogen reactive groups may be the same or different.

The carbon-carbon unsaturated bond possessed by the reactive additive means a carbon-carbon double bond, a carbon-carbon triple bond, or a combination thereof, and a carbon-carbon double bond is preferred. Among these, as the reactive additive, a carbon-carbon unsaturated bond containing a vinyl group and / or a (meth) acrylfluorenyl group is preferable. Furthermore, it is preferable that the active hydrogen reactive group is a reactive additive selected from the group consisting of an epoxy group, a glycidyl group, and an isocyanate group, and it is more preferable that the active hydrogen reactive group has an acryl group and an isocyanate group. Reactive additive.

Specific examples of the reactive additive include compounds having a (meth) acrylfluorenyl group and an epoxy group, such as methacryloxy glycidyl ether or propylene glycol oxyglycidyl ether; oxetane acrylic acid Compounds such as esters or oxetane methacrylates with (meth) acrylfluorenyl groups and oxetanyl groups; lactone acrylates or lactone methacrylates with (meth) acrylfluorene groups and Compounds with lactone groups; Compounds with vinyl and oxazoline groups such as vinyloxazoline or isopropenyloxazoline; isocyanatomethyl acrylate, isocyanatomethyl methacrylate, acrylic acid 2 -An oligomer of a compound having a (meth) acrylfluorenyl group and an isocyanate group, such as ethyl isocyanate or 2-isocyanate ethyl methacrylate. In addition, examples thereof include compounds having a vinyl group or vinylidene group and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride. Of these, methacrylic acid oxyglycidyl ether, propylene glycol oxyglycidyl ether, methyl isocyanate acrylate, methyl isocyanate methacrylate, vinyl oxazoline, and acrylic acid 2- Ethyl isocyanate, 2-isocyanate ethyl methacrylate or the above oligomers, particularly preferably methyl isocyanate acrylate, 2-isocyanate ethyl acrylate or the above oligomers Thing.

Specifically, a compound represented by the following formula (Y) is preferable.

[Chemical 14]

[In formula (Y), n represents an integer from 1 to 10, and R ^{1 ′} represents a divalent aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms or a divalent aromatic hydrocarbon group having 5 to 20 carbon atoms; each repeating Among the two R ^2's in the unit, one is -NH- and the other is a group represented by> NC (= O) -R ^{3 '} ; R ^3' represents a hydroxyl group or a group having a carbon-carbon unsaturated bond ;
In R ^{3 ′} in formula (Y), at least one R ^{3 ′} is a group having a carbon-carbon unsaturated bond]

Among the reactive additives represented by the formula (Y), a compound represented by the following formula (YY) (hereinafter sometimes referred to as a compound (YY)) is particularly preferred (in addition, n has the same meaning as described above).

[Chemical 15]

Compound (YY) can be used as it is, or it can refine | purify it as needed. Examples of commercially available products include Laromer (registered trademark) LR-9000 (manufactured by BASF).

When the polarizing layer-forming composition contains a reactive additive, the content of the reactive additive is usually 0.01 to 10 parts by mass, and preferably 0.1 to 5 parts by mass based on 100 parts by mass of the liquid crystal compound.

(Protective Lamination Step)
In the protective layer laminating step, as shown in FIG. 3 (c), the polarizing layer 21 of the laminating film 62 prepared in the preparing step is laminated with a covering area 35a for covering the polarizing layer 21 and for exposing the polarizing layer 21 The protective layer 35 of the exposed area 35b. Thereby, the laminated film 63 with a protective layer can be obtained. The exposed area 35b may be an opening of the protective layer 35, for example. The coating region 35 a can prevent the liquid substance from coming into contact with the polarizing layer 21 when a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer 21 described below is brought into contact with the laminated film 63 with a protective layer. On the other hand, in the exposed area 35 b of the protective layer 35, a liquid substance can be brought into contact with the polarizing layer 21.

As described below, when the polarizing layer 21 is in contact with a liquid substance, the liquid substance penetrates into the polarizing layer 21 and the function of the dichroic pigment as a pigment disappears. Therefore, the exposed region 35b is preferably formed corresponding to a region in the polarizing layer 21 in which the content of the dichroic pigment is reduced. For example, when manufacturing the polarizing film 1 shown in FIGS. 1 (a) and (b), it is preferable to determine the shape of the polarizing film 1 according to the shape of the second region 11b. For example, if the top view shape of the second region 11b is circular; oval; oval; triangle, square, rectangle, rhombus, and other polygons; line; band; wave; It may be formed in accordance with the shape.

For example, when the exposed area 35b is circular, its diameter is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the exposed area 35b is oval or oblong, its long axis is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. In the case where the exposed area 35b is polygonal, the diameter of the imaginary circle drawn in the polygonal inscribed manner is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. As described below, since the liquid substance penetrates into the liquid crystal layer, the size of the exposed region 35b may not be the same as that of the second region 11b, but may be formed slightly smaller than the second region 11b.

The covering region 35 a of the protective layer 35 is preferably formed to correspond to a region in the polarizing layer 21 that does not reduce the content of the dichroic pigment. For example, when manufacturing the polarizing film 1 shown in FIGS. 1 (a) and (b), it is preferable to determine the shape of the polarizing film 1 according to the shape of the first region 11a.

The protective layer 35 can be used for a region in which the exposed region 35b is formed on the sheet-like substrate. The area that becomes the exposed area 35b can be formed by a method such as mechanical punching of a specific portion of the sheet-like substrate by punching, cutting, spraying water, etc .; and cutting the sheet by laser ablation, chemical dissolution, etc. Method for removing a specific portion of the substrate.

As the sheet-like base material forming the protective layer 35, as long as it is insoluble in the liquid substance when it comes into contact with the liquid substance that can reduce the content of the dichroic pigment in the liquid crystal layer described below, the liquid substance The material is not particularly limited as long as it has durability in ultraviolet irradiation after removal or contact with a liquid substance. As the sheet-like base material for forming the protective layer 35, for example, the same material as that of the base material layer 13 can be used. It is particularly preferable to use a resin base material, and it is more preferable to use the protective layer 35 to easily prevent the exposed area of the protective layer 35 from becoming exposed. Polyester resins such as polyethylene terephthalate that are deformed in areas (such as openings) in 35b.

The protective layer 35 preferably has an adhesive layer for bonding to the polarizing layer 21. In order to peel off the protective layer 35 as described below, the adhesive layer is preferably peelable from the polarizing layer 21. The thickness of the protective layer 35 is usually 20 μm or more, more preferably 30 μm or more, and usually 250 μm or less, and preferably 200 μm or less.

(Decoloring step)
In the decoloring step, the polarizing layer can be obtained by contacting the laminated film 63 with a protective layer obtained in the protective layer laminating step with a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer 21, and the polarizing layer can be obtained. The decoloring laminated film 64 (FIG. 3 (d)) that reduces the content of the dichroic pigment in a part of the area 21. The protective layer 35 of the laminated film 63 with a protective layer has a covered area 35a for covering the polarizing layer 21 and an exposed area 35b for exposing the polarizing layer 21, so that a liquid substance and a polarizing layer can be provided in the exposed area 35b. 21 contacts. As a result, the content of the dichroic pigment can be reduced in the region in contact with the liquid substance in the polarizing layer 21.

The contact between the laminated film 63 with the protective layer and the liquid substance can be performed by immersing the laminated film 63 with the protective layer in the liquid substance, and coating, spraying, and dropping the liquid substance onto the liquid substance. The laminated film 63 having a protective layer and the like are preferably prepared by immersing the laminated film 63 with a protective layer in a liquid substance. Thereby, in the polarizing layer 21, the surface of the polarizing layer 21 exposed from the exposed area 35b of the protective layer 35 is in contact with the liquid and penetrates into the interior of the polarizing layer 21. The details are not clear, but it is considered that the liquid substance penetrated into the polarizing layer 21 decomposes or reacts with the dichroic pigment in the polarizing layer 21, thereby making the dichroic pigment function as a pigment. disappear. Thereby, the second region 11b, which is a region having a lower content rate than the other regions, is formed on a part of the polarizing layer 21, and a decolored laminated film 64 having the liquid crystal layer 11 can be obtained (FIG. 3 (d)).

In the surface of the polarizing layer 21, in the area covered by the covering area 35a of the protective layer 35, the polarizing layer 21 is not in direct contact with the liquid substance, so the liquid substance is difficult to penetrate into the polarizing layer 21, and the dichroic pigment is difficult to disappear. In contrast, in the polarizing layer 21, in the area exposed from the exposed area 35b of the protective layer 35, the polarizing layer 21 is in direct contact with the liquid substance, so the liquid substance easily penetrates into the polarizing layer 21, and the dichroic pigment is easy to disappear. . Therefore, in the decolorized laminated film 64 shown in FIG. 3 (d), a region corresponding to the exposed region 35 b in the polarizing layer 21 may have a second region having a low polarization rate as a dichroic pigment, which is lower than other regions. 11b 的 温度 层 11。 11b of the liquid crystal layer 11.

In this way, by using the polarizing layer 21 with the protective layer-laminated film 63 in which the exposed layer 35b of the protective layer 35 is arranged in the region where the content of the dichroic pigment is to be reduced, the polarizing layer 21 can be formed as desired. The liquid crystal layer 11 in which the content ratio of the dichroic dye is reduced in the position. However, in order to allow the liquid substance to penetrate into the polarizing layer 21 and to eliminate the function of the dichroic pigment, it is preferable to reduce the dichroic substance so that the liquid substance does not penetrate into the region where the content of the dichroic pigment is not required to be reduced. The method of the content ratio of the sexual pigment, adjust the thickness of the protective layer 35, the size of the exposed area 35b, the concentration of the liquid substance, the immersion time of the laminated film with the protective layer in the liquid substance, and the liquid substance with the protection A coating amount, a spray amount, a dropping amount, or the like on the layered laminated film 63.

The liquid substance capable of reducing the content of the dichroic pigment in the polarizing layer 21 is not particularly limited as long as the content of the dichroic pigment can be reduced. For example, a peroxide (hydrogen peroxide, peroxide, etc.) can be suitably used. Sodium carbonate, etc.), chlorine compounds (sodium hypochlorite, etc.), acids (sulfuric acid, nitric acid, hexafluorophosphoric acid), bases (sodium hydroxide, potassium hydroxide), and the like. Among them, acids such as sulfuric acid, nitric acid, and hexafluorophosphoric acid are preferred. These liquids can be used alone or in combination.

The contact conditions for bringing the laminated film 63 with a protective layer into contact with the liquid can be appropriately selected depending on the thickness of the polarizing layer 21 or the range in which the content ratio of the dichroic pigment is reduced. The concentration of the liquid substance is, for example, preferably from 20 to 80% by mass, and more preferably from 30 to 70% by mass. The temperature of the liquid is preferably 50 to 150 ° C, and more preferably 80 to 120 ° C.

In the decoloring step, it is preferable that the laminated film 63 with a protective layer is in contact with the liquid substance, and a part of the polarizing layer 21 is formed in a region where the content of the dichroic pigment is lower than that of other regions, and then the first part of the washing liquid substance is set. 1 washing step. The first washing step can be performed using an organic solvent such as water or alcohol.

(Peeling step)
In the peeling step, the protective layer 35 is peeled from the decolored laminated film 64 obtained in the decoloring step. Thereby, the polarizing film 1 (FIG. 1 (a) and (b)) in which the 2nd area | region 11b which is a dichroic dye content lower than the other area | region is formed in one part of the liquid crystal layer 11 can be obtained.

The polarizing film 1 shown in FIG. 1 (b) may be used by further peeling off the base material layer 13. In this case, the alignment layer 12 and the base material layer 13 may be peeled together. For example, peeling of the base material layer 13 may be performed after bonding the liquid crystal layer 11 of the polarizing film 1 to a member constituting a display device, a retardation layer, or the like.

(Continuous manufacturing method of polarizing film)
The manufacturing method of the polarizing film 1 is preferably continuously manufactured in a roll-to-roll format. In this case, in the preparation step, a laminated film wound into a roll shape is prepared, and the laminated film is rolled out and transported, and the protective layer lamination step, decoloring step, and peeling step may be continuously performed. In the protective layer lamination step, the protective layer wound into a roll shape is rolled out and transported, and the protective layer is laminated on the laminated film to obtain a laminated film with a protective layer. In the decoloring step, one side of the laminated film with a protective layer is continuously conveyed while passing through a liquid-filled liquid bath, or one of the laminated film with a protective layer is continuously conveyed while being coated, sprayed, or dripped. It is sufficient to obtain a decolorized laminated film. In the peeling step, the protective layer may be continuously peeled from the decolorizing laminated film, and the polarizing film may be rolled into a roll shape to be a rolled body. The polarizing film continuously manufactured as described above may have a length of, for example, 10 m or more.

When the preparation step includes an alignment layer forming step, the substrate layer wound into a roll shape is rolled out and conveyed, and the composition for forming an alignment layer is continuously applied to the substrate layer by a coating device. It is sufficient to form an alignment layer. When the preparation step includes a step of forming a polarizing layer, a substrate layer with an alignment layer is continuously transported, and a combination of a layer for forming a polarizing layer is coated on the side of the substrate layer with the alignment layer on the side where the alignment layer is formed. It is sufficient to form a polarizing layer.

In the polarizing film 1 manufactured in this first manufacturing method, the difference in thickness between the first region 11a and the second region 11b can be reduced to, for example, 2 μm or less, so that a stepless polarizing film 1 can be obtained. Thereby, even if another film is laminated on the polarizing layer 21 with an adhesive, other films can be laminated without embedding bubbles.

<Method for Manufacturing Polarizing Film (Second Manufacturing Method)>
The polarizing film 1 can be manufactured by the second manufacturing method shown below in addition to the first manufacturing method described above. FIG. 4 is a schematic cross-sectional view showing an example of a liquid material contacting step in the method of manufacturing the polarizing film 1 shown in FIG. 1 (b). The second manufacturing method of the polarizing film 1 has the following steps:
The preparation step is to prepare a build-up film 62 having a polarizing layer 21 containing a liquid crystal compound and a dichroic pigment on at least one side of the substrate layer 13 (FIG. 3 (b)); and a liquid contact step, that is, by A part of the polarizing layer 21 of the laminated film 62 is brought into contact with a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer 21, and the content of the dichroic pigment is reduced in the above-mentioned part of the region (Figure 4) Thus, the polarizing film 1 shown in FIGS. 1 (a) and (b) can be manufactured.

The preparation steps in the second manufacturing method are the same as the preparation steps in the first manufacturing method described above with reference to Figs. 3 (a) and (b). With this preparation step, the build-up film 62 having the polarizing layer 21 is prepared.

In this second manufacturing method, a part of a region of the polarizing layer 21 on the laminated film 62 is brought into contact with a liquid substance (FIG. 4). The liquid substance used at this time can reduce the content of the dichroic pigment in a part of the polarizing layer 21, and can use the same liquid substance as the liquid substance used in the decoloring step in the first manufacturing method. . As a method of contacting a partial region of the polarizing layer 21 with a liquid substance, for example, a so-called inkjet method in which a liquid substance is dropped and applied to the partial region as shown in FIG. 4 is mentioned. By bringing the polarizing layer 21 into contact with the liquid substance, the liquid substance can penetrate into a part of the region of the polarizing layer 21, reduce the content of the dichroic pigment, and form a low polarization region.

The second manufacturing method preferably includes a second cleaning step of rinsing the liquid substance on the polarizing layer 21 after bringing the polarizing layer 21 into contact with the liquid substance. The second cleaning step can be performed using an organic solvent such as water or alcohol used in the first cleaning step in the first manufacturing method. Thereby, the polarizing film 1 shown in FIG. 1 (b) can be obtained.

Regarding the second manufacturing method, similarly to the first manufacturing method, the polarizing film 1 may be continuously manufactured in a roll-to-roll format, for example. In this case, a laminated film wound into a roll shape is prepared in the preparation step, and the laminated film is rolled out while being conveyed, and the liquid substance contact step may be continuously performed. In the liquid material contacting step, while the laminated film is continuously conveyed, the liquid material is applied dropwise to obtain a polarizing film, and the obtained polarizing film may be rolled into a roll shape and formed into a rolled body. The polarizing film continuously manufactured as described above may have a length of, for example, 10 m or more.

When the preparation step includes an alignment layer forming step, the substrate layer wound into a roll shape is rolled out and conveyed, and the composition for forming an alignment layer is continuously applied to the substrate layer by a coating device. It is sufficient to form an alignment layer. When the preparation step includes a polarizing layer forming step, the polarizing layer-forming composition is applied while continuously transporting the base material layer with the alignment layer, and applying the polarizing layer on the side of the base material layer with the alignment layer on the side where the alignment layer is formed. It is sufficient to form a polarizing layer.

With this second manufacturing method, the difference in thickness between the first region 11a and the second region 11b can be reduced to, for example, 2 μm or less, and the step-free polarizing film 1 can be obtained. Thereby, even if another film is laminated on the polarizing layer 21 with an adhesive, other films can be laminated without embedding bubbles.

＜ Manufacturing method of circular polarizing plate ＞
The circular polarizing plate can be manufactured by laminating a polarizing film 1 and a retardation layer. As described above, when the polarizing film is a continuous polarizing film having a length of 10 m or more, it is preferable to use a long retardation layer having a length of 10 m or more as the retardation layer, and continuously carry two One is an area layer of a long polarizing film and a long retardation layer, thereby forming a long laminated body. At this time, it is preferable to apply an adhesive or an adhesive to at least one of the long polarizing film and the long retardation layer to laminate the two.

For the method of manufacturing a circular polarizing plate, in order to mount a polarizing film on a display device of a specific size, etc., there may be a method of cutting a long laminated body obtained by laminating a long polarizing film and a long retardation layer into a unit of a specific size. Film steps. In the cutting step, the long laminated body is preferably cut in at least one of a length direction and a width direction of the long laminated body. In this case, it is preferable to determine the cutting position in the long laminated body by arranging the second region 11b of the liquid crystal layer 11 in the cut single piece at a specific position.
[Example]

The present invention will be specifically described based on examples. However, the present invention is not limited by these examples.

[Visual sensitivity correction polarization (Py) and visual sensitivity correction transmittance (Ty)]
(Production of evaluation samples)
A composition for forming an alignment layer and a composition for forming a polarizing layer used in each of Examples, Comparative Examples, and Reference Examples were prepared. In addition, a substrate obtained by cutting out a film of 40 mm × 40 mm in the same film as that used as the substrate layer in each of Examples, Comparative Examples, and Reference Examples was prepared as a substrate layer for evaluation. Using these, the protective layer was not used in Examples 1, 2, Comparative Examples, and Reference Examples. In Example 3, the entire surface of the polarizing layer was brought into contact with the solution instead of dropping the solution on the polarizing layer. Samples for evaluation were obtained in the same order as the production of the polarizing films of each of the examples, comparative examples, and reference examples.

(Polarity (Py) and Transmittance (Ty))
For the evaluation sample, the visual sensitivity correction unit transmittance (Ty) and the visual sensitivity correction polarization (Py) were calculated in the following order. A spectrophotometer (UV-3150, manufactured by Shimadzu Corporation) equipped with a folder with a polarizing element is used to measure the transmittance in the direction of the transmission axis in the range of 380 nm to 780 nm by the dual beam method (T ₁ ) and transmittance (T ₂ ) in the absorption axis direction. The folder is provided with a sieve on the reference side to cut off the light amount by 50%. Use the following (Equation 1) and (Equation 2) to calculate the transmittance and polarization at each wavelength, and then perform visual sensitivity correction in accordance with JIS Z 8701's 2-degree field of view (C light source) to calculate the visual sensitivity corrected transmittance (Ty ) And visual sensitivity correction polarization (Py).
Polarization [%] = {(T ₁ －T ₂ ) / (T ₁ ＋ T ₂ )} × 100 (Equation 1)
Cell transmittance [%] = (T ₁ + T ₂ ) / 2 (Equation 2)

[Example 1]
(Manufacture of alignment layer forming composition)
The following components were mixed, and the obtained mixture was stirred at 80 ° C. for 1 hour, thereby obtaining a composition for forming an alignment layer as a composition for forming a photo-alignment film.
・ 2 parts of polymer with photoreactive group shown below
[Chemical 16]

・ Solvent: 98 parts of o-xylene

(Production of composition for forming polarizing layer)
The following components were mixed, and it stirred at 80 degreeC for 1 hour, and obtained the composition for polarizing layer formation. As the dichroic pigment, an azo pigment described in Examples of Japanese Patent Laid-Open No. 2013-101328 is used.
・ 75 parts of polymerizable liquid crystal compound represented by formula (1-6)
[Chemical 17]

・ 25 parts of polymerizable liquid crystal compound represented by formula (1-7)
[Chemical 18]

・ 2.8 parts of dichroic pigment (1) shown below
[Chemical 19]

・ 2.8 parts of dichroic pigment (2) shown below
[Chemical 20]

・ 2.8 parts of dichroic pigment (3) shown below
[Chemical 21]

・ 6 parts of polymerization initiator shown below
2-dimethylamino-2-benzyl-1- (4-olinylphenyl) butane-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals)
・ 1.2 parts of polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
・ 250 parts of cyclopentanone

(Manufacture of polarizing film)
A triethylammonium cellulose film (KC4UY-TAC manufactured by Konica Minolta Co., Ltd., thickness 40 μm) was cut out 20 × 20 mm as a base layer, and the surface was corona treated (AGF-B10, Kasuga Electric Co., Ltd. Manufacturing). After applying the composition for forming an alignment layer on the surface of the film subjected to corona treatment using a bar coater, it was dried in a drying oven set at 120 ° C. for 1 minute to obtain a coating layer for the alignment layer. A polarized UV irradiation device (SPOT CURE SP-7; manufactured by Oxtail Electric Co., Ltd.) was used to irradiate polarized UV onto the coating layer for an alignment layer at a cumulative light amount of 50 mJ / cm ² (based on a 313 nm standard) to form an alignment layer. . The polarizing layer-forming composition was applied on the obtained alignment layer using a bar coater, and then dried in a drying oven set at 110 ° C. for 1 minute. Thereafter, a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Oxtail Electric Co., Ltd.) was used to irradiate ultraviolet rays (wavelength: 365 nm under a nitrogen environment, and a cumulative light amount of wavelength 365 nm: 1000 mJ / cm ² ) to obtain a liquid crystal. A polarizing layer composed of a compound and a dichroic pigment. A protective layer (AY-638 manufactured by Fujimori Industry Co., Ltd.) was formed on the polarizing layer to form a hole through a hole punching machine; a polyester film having a thickness of 15 μm was provided on a polyester film having a thickness of 38 μm. Adhesive layer), then in a 50 wt% solution of propylene carbonate in diphenyl 4-thiophenoxyphenyl sulfonium hexafluorophosphate (CPI-100P, manufactured by SAN-APRO Co., Ltd.) at 120 Immerse at 60 ° C for 60 seconds. Thereafter, the protective layer was peeled to obtain a polarizing film.

The appearance of the obtained polarizing film was visually observed. As a result, it was clearly confirmed that a circular region (low-polarizing region) in which a polarizing layer does not exist, and it was found that a polarizing film having a polarizing region and a low-polarizing region was obtained. In addition, an evaluation sample was prepared according to the above procedure, and the visual sensitivity-corrected transmittance (Ty) and the visual sensitivity-corrected polarization (Py) were calculated. The results are shown in Table 1.

[Example 2]
Except the use of a hard-coated film on the surface of a quarter-wave plate (ZEONOR FILM, Japan Zeon Corporation, in-plane retardation value Ro: 138 nm) as a uniaxially stretched film of a cyclic olefin resin. A triethylammonium cellulose film was used as a substrate layer, and a polarizing film was obtained in the same manner as in Example 1 except that the retardation axis and the absorption axis of the polarizing layer were 45 °. In addition, an evaluation sample was prepared according to the above procedure, and the visual sensitivity-corrected transmittance (Ty) and the visual sensitivity-corrected polarization (Py) were calculated. The results are shown in Table 1.

[Example 3]
50% of propylene carbonate of diphenyl 4-thiophenoxyphenyl sulfonium hexafluorophosphate (manufactured by SAN-APRO Co., Ltd., CPI-100P) was added dropwise onto the polarizing layer, except using a dropper. A polarizing film was obtained in the same manner as in Example 1 except that the% solution was used instead of lamination to form a protective layer for the opening portion by making a hole with a hole punch. In addition, an evaluation sample was prepared according to the above procedure, and the visual sensitivity-corrected transmittance (Ty) and the visual sensitivity-corrected polarization (Py) were calculated. The results are shown in Table 1.

[Comparative example]
Except for using a 50 wt% solution of propylene carbonate of diphenyl 4-thiophenoxyphenyl sulfonium hexafluorophosphate (manufactured by SAN-APRO Co., Ltd., CPI-100P) at room temperature with methanol, A polarizing film was obtained in the same manner as in Example 1. The appearance of the obtained polarizing film was visually observed. As a result, it was impossible to confirm a region where no polarizing layer was present, and it was found that a polarizing film having a polarized region and a low-polarized region could not be obtained. In addition, an evaluation sample was prepared according to the above procedure, and the visual sensitivity-corrected transmittance (Ty) and the visual sensitivity-corrected polarization (Py) were calculated. The results are shown in Table 1.

[Reference example]
Except for not using a 50 wt% solution of a propylene carbonate of diphenyl 4-thiophenoxyphenyl sulfonium hexafluorophosphate (manufactured by SAN-APRO Corporation, CPI-100P), the same procedure as in Example 1 was used. A polarizing film was obtained in the same manner. The appearance of the obtained polarizing film was visually observed. As a result, it was impossible to confirm a region where no polarizing layer was present, and it was found that a polarizing film having a polarized region and a low-polarized region could not be obtained. In addition, an evaluation sample was prepared according to the above procedure, and the visual sensitivity-corrected transmittance (Ty) and the visual sensitivity-corrected polarization (Py) were calculated. The results are shown in Table 1.

In addition, the values of the visual sensitivity-corrected transmittance (Ty) and the visual sensitivity-corrected polarization (Py) measured in each of the examples, comparative examples, and reference examples shown in Table 1 are the visual sensitivity-corrected transmission including the substrate layer. The value of the correction rate (Ty) and the visual sensitivity correction polarization (Py), the visual sensitivity correction transmittance (Ty) of the base material layer alone is 92%, and the visual sensitivity correction polarization (Py) value of the base material layer It is 0%. Therefore, when the substrate layer is removed in each of the examples, comparative examples, and reference examples shown in Table 1, it is considered that the value of the visual sensitivity correction transmittance (Ty) is greater than the value shown in Table 1, and the visual sensitivity is The value of the corrected polarization (Py) is the same as that shown in Table 1.

[Table 1]

1‧‧‧ polarizing film

5a ～ 5c‧‧‧circular polarizing plate

11‧‧‧LCD layer

11a‧‧‧Region 1

11b‧‧‧Zone 2

12‧‧‧Alignment layer

13‧‧‧ substrate layer

15‧‧‧ retardation layer

21‧‧‧polarizing layer

35‧‧‧ protective layer

35a‧‧‧ Covered area

35b‧‧‧ exposed area

61‧‧‧Substrate layer with alignment layer

62‧‧‧ laminated film

63‧‧‧Laminated film with protective layer

64‧‧‧decoloration laminated film

FIG. 1 (a) is a schematic plan view showing an example of the polarizing film of the present invention, and (b) is a cross-sectional view taken along the line X-X of (a).

2 (a) to (c) are schematic cross-sectional views each showing an example of a circular polarizing plate of the present invention.

3 (a) to (d) are schematic cross-sectional views showing an example of a layer structure obtained in each step of the manufacturing steps of the polarizing film of the present invention.

FIG. 4 is a schematic cross-sectional view showing an example of a liquid material contacting step in the method of manufacturing a polarizing film of the present invention.

Claims (20)

A polarizing film having a liquid crystal layer, and The liquid crystal layer contains a liquid crystal compound and has at least two regions that are distinguished according to the value of the visual sensitivity correction polarization, The contents of the dichroic pigments in the at least two regions are different from each other. The polarizing film of claim 1, further comprising a base material layer, and An alignment layer laminated on at least one side of the substrate layer, and The liquid crystal is laminated on the alignment layer. The polarizing film according to claim 2, wherein the alignment layer contains a photo-alignment polymer. The polarizing film according to any one of claims 1 to 3, wherein the liquid crystal compound contains a polymerizable liquid crystal compound. The polarizing film according to any one of claims 1 to 4, wherein the liquid crystal layer has a first region containing a dichroic pigment and a content ratio of the dichroic pigment that is lower than that of the first region, The above-mentioned first area has a visual sensitivity correction polarization of 90% or more. The visual sensitivity correction polarization in the second region is 10% or less. The polarizing film according to any one of claims 1 to 5, wherein the liquid crystal layer has a first region containing a dichroic pigment and a content rate of the dichroic pigment that is lower than the second region of the first region, The visual sensitivity correction unit transmittance of the first region is 35% or more. The visual sensitivity correction unit transmittance of the second region is 80% or more. If the polarizing film of claim 5 or 6, wherein the plan view shape of the second region is a circle, an ellipse, an oval, or a polygon, When the second area is circular, the diameter is 5 cm or less. When the second area is oval or oblong, the long diameter is 5 cm or less. In the case where the second region is a polygon, the diameter of the imaginary circle drawn by the polygon inscribed above is 5 cm or less. The polarizing film according to any one of claims 5 to 7, wherein the first region described above shows a Blegg peak in an X-ray diffraction measurement. The polarizing film according to any one of claims 1 to 8, which further has a base material layer, The base material layer has a 1/4 wavelength plate function. The polarizing film according to any one of claims 1 to 9, wherein the length of the polarizing film is 10 m or more. A circular polarizing plate is formed by laminating a polarizing film according to any one of claims 1 to 8 and 10 and a retardation having a 1/4 wavelength plate function. A method for manufacturing a polarizing film includes the following steps: The preparation step is to prepare a laminated film having a polarizing layer containing a liquid crystal compound and a dichroic pigment on at least one side of the base material layer; and The liquid substance contacting step is to contact a part of the polarizing layer of the laminated film with a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer, and contact the liquid substance in a part of the polarizing layer. Reduce the content of dichroic pigments. For example, the method for manufacturing a polarizing film according to claim 12, wherein the liquid-liquid contacting step includes the following steps: The protective layer lamination step is obtained by laminating the polarizing layer on the polarizing layer of the laminated film prepared in the preparing step with a protective layer for covering the polarizing layer and an exposed area for exposing the polarizing layer. Laminated film with protective layer; The decoloring step is to obtain a dichroic pigment in a partial region of the polarizing layer by contacting the laminated film with a protective layer and a liquid substance that can reduce the content of the dichroic pigment in the polarizing layer. Decolorized laminated film with reduced content; and In the peeling step, the protective layer is peeled from the decolored laminated film. For example, the method for manufacturing a polarizing film according to claim 13, wherein the planar shape of the exposed area in the protective layer is circular, oval, oblong, or polygonal, When the exposed area is circular, the diameter is 5 cm or less. In the case where the above-mentioned exposed area is oval or oblong, the long diameter is 5 cm or less, In the case where the exposed area is polygonal, the diameter of the imaginary circle drawn in the manner of the polygon inscribed above is 5 cm or less. The method for manufacturing a polarizing film according to any one of claims 12 to 14, wherein the above preparation steps include the following steps: The alignment layer forming step is to form an alignment layer by applying the composition for forming an alignment layer on one side of the substrate layer; and The polarizing layer forming step is to form a polarizing layer by applying a composition for forming a polarizing layer containing the liquid crystal compound and the dichroic pigment on the surface of the base material layer on which the alignment layer is formed. The method for manufacturing a polarizing film according to claim 15, wherein the composition for forming an alignment layer contains a photo-alignment polymer, The alignment layer forming step is performed by applying polarized light to an application layer for an alignment layer formed by applying the composition for forming an alignment layer to form the alignment layer. The method for producing a polarizing film according to claim 15 or 16, wherein the liquid crystal compound is a polymerizable liquid crystal compound, The step of forming the polarizing layer is to irradiate the coating layer for a polarizing layer formed by applying the composition for forming a polarizing layer with active energy rays to form the polarizing layer. The method for manufacturing a polarizing film according to any one of claims 12 to 17, wherein the length of the polarizing film is 10 m or more. A method for manufacturing a circular polarizing plate includes a step of laminating a retardation layer, and a polarizing film manufactured by the method for manufacturing a polarizing film according to any one of claims 12 to 18 and a polarizing film having a 1/4 wavelength plate function. Phase difference layered. For example, the method for manufacturing a circular polarizing plate according to item 19, wherein the polarizing film is a long polarizing film with a length of 10 m or more, The phase difference layer is a long phase difference layer with a length of 10 m or more. The step of laminating the phase difference is to form a long laminated body by laminating the long polarizing film and the long phase difference, It further includes a cutting step of cutting the long laminated body into a single piece.