JPWO2019082745A1 - Polarizing film and its manufacturing method - Google Patents

Abstract

The polarizing film has a liquid crystal layer. The liquid crystal layer contains the liquid crystal compound and has at least two regions distinguished by the value of the luminosity factor correction polarization degree. At least two regions differ from each other in the content of the dichroic dye.

Description

The present invention relates to a polarizing film and a method for producing the same, and more particularly to a polarizing film having a layer containing a liquid crystal compound and a dichroic dye and a method for producing the same.

Organic EL display devices that use organic light emitting diodes (OLEDs) are not only lighter and thinner than liquid crystal display devices, but also have a wide viewing angle, fast response speed, and high image quality such as high contrast. Because it can be realized, it is used in various fields such as smartphones, TVs, and digital cameras. It is known that an organic EL display device uses a circularly polarizing plate or the like to improve antireflection performance in order to suppress a decrease in visibility due to reflection of external light.

As the polarizing film used for such a circular polarizing plate, Japanese Patent Application Laid-Open No. 2015-206852 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2015-212823 (Patent Document 2) describe liquid crystal curing patterned on a substrate. A patterned polarizing film in which films are laminated is described.

JP-A-2015-206852 JP-A-2015-212823

An object of the present invention is to provide a novel polarizing film having at least two regions having different luminosity factor correction polarization values and a method for producing the same.

The present invention provides the polarizing film shown below and a method for producing the same.
[1] A polarizing film having a liquid crystal layer.
The liquid crystal layer contains a liquid crystal compound and has at least two regions distinguished by a value of luminosity factor correction polarization.
The at least two regions are polarizing films in which the contents of the dichroic dyes are different from each other.
[2] Further, the base material layer and
It has an orientation layer laminated on at least one side of the base material layer, and has.
The polarizing film according to [1], wherein the liquid crystal layer is laminated on the alignment layer.
[3] The polarizing film according to [2], wherein the alignment layer contains a photoalignable 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 liquid crystal layer has a first region containing a dichroic dye and a second region in which the content of the dichroic dye is lower than that of the first region.
The luminosity factor correction polarization degree in the first region is 90% or more.
The polarizing film according to any one of [1] to [4], wherein the degree of luminosity factor correction polarization in the second region is 10% or less.
[6] The liquid crystal layer has a first region containing a dichroic dye and a second region in which the content of the dichroic dye is lower than that of the first region.
The luminosity factor correction single transmittance in the first region is 35% or more.
The polarizing film according to any one of [1] to [5], wherein the visible sensitivity correction simple substance transmittance of the second region is 80% or more.
[7] The second region has a circular, elliptical, oval, or polygonal shape in a plan view.
When the second region is circular, the diameter is 5 cm or less.
When the second region is elliptical or oval, the major axis is 5 cm or less.
The polarizing film according to any one of [5] and [6], wherein when the second region is a polygon, the diameter of the virtual circle drawn so that the polygon is inscribed is 5 cm or less.
[8] The polarizing film according to any one of [5] to [7], wherein the first region shows a Bragg peak in X-ray diffraction measurement.
[9] Further, it has a base material layer and
The polarizing film according to any one of [1] to [8], wherein the base material layer has a 1/4 wave plate function.
[10] The polarizing film according to any one of [1] to [9], wherein the length of the polarizing film is 10 m or more.
[11] A circular polarizing plate formed by laminating the polarizing film according to any one of [1] to [8] and [10] and a retardation layer having a 1/4 wave plate function.
[12] A preparatory step of preparing 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.
By contacting a part of the polarizing layer of the laminated film with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer, the dichroic dye is brought into contact with a part of the polarizing layer. A method for producing a polarizing film, comprising a liquid material contacting step of reducing the content of the polarizing film.
[13] The liquid material contacting step is
A protective layer is formed by laminating a protective layer having a coating region for coating the polarizing layer and an exposed region for exposing the polarizing layer on the polarizing layer of the laminated film prepared in the preparation step. Protective layer lamination process to obtain laminated film with
By contacting the laminated film with the protective layer with a liquid material capable of reducing the content of the dichroic dye in the polarizing layer, the content of the dichroic dye is reduced in a part of the polarizing layer. Decolorization process to obtain a decolorized laminated film and
The method for producing a polarizing film according to [12], which comprises a peeling step of peeling the protective layer from the decolorized laminated film.
[14] The exposed region in the protective layer has a circular, elliptical, oval, or polygonal shape in a plan view.
When the exposed area is circular, the diameter is 5 cm or less.
When the exposed area is elliptical or oval, the major axis is 5 cm or less.
The method for producing a polarizing film according to [13], wherein when the exposed region is a polygon, the diameter of the virtual circle drawn so that the polygon is inscribed is 5 cm or less.
[15] The preparation step is
An alignment layer forming step of applying a composition for forming an alignment layer on one side of the base material layer to form an alignment layer,
A polarizing layer forming step of applying a polarizing layer forming composition containing the liquid crystal compound and the dichroic dye to the surface of the base material layer on the side where the alignment layer is formed to form the polarizing layer. The method for producing a polarizing film according to any one of [12] to [14].
[16] The composition for forming an alignment layer contains a photoalignable polymer and contains.
The polarizing film according to [15], wherein in the alignment layer forming step, the alignment layer coating layer formed by coating the alignment layer forming composition is irradiated with polarized light to form the alignment layer. Production method.
[17] The liquid crystal compound is a polymerizable liquid crystal compound.
In the polarizing layer forming step, the polarizing layer coating layer formed by coating the polarizing layer forming composition is irradiated with active energy rays to form the polarizing layer, [15] or [16]. The method for producing a polarizing film according to.
[18] The method for producing a polarizing film according to any one of [12] to [17], wherein the polarizing film has a length of 10 m or more.
[19] A retardation layer laminating step of laminating a polarizing film produced by the method for producing a polarizing film according to any one of [12] to [18] and a retardation layer having a 1/4 wave plate function. A method for manufacturing a circularly polarizing plate.
[20] The polarizing film is a long polarizing film having a length of 10 m or more.
The retardation layer is a long retardation layer having a length of 10 m or more.
In the retardation layer laminating step, a long laminate is formed by laminating the long polarizing film and the long retardation layer.
The method for producing a circular polarizing plate according to [19], further comprising a cutting step of cutting the long laminate into single sheets.

According to the present invention, it is possible to provide a polarizing film having at least two regions in which the values of the luminosity factor correction polarization degree are different from each other, and a method for producing the same.

(A) is a schematic plan view showing an example of the polarizing film of the present invention, and (b) is a sectional view taken along line XX of (a). (A) to (c) are schematic cross-sectional views showing an example of the circular polarizing plate of the present invention, respectively. (A) to (d) are schematic cross-sectional views showing an example of a layer structure obtained in each step of the polarizing film manufacturing process of the present invention. It is the schematic sectional drawing which shows an example of the liquid matter contact process in the manufacturing method of the polarizing film of this invention.

Hereinafter, preferred embodiments of the polarizing film of the present invention and the method for producing the same will be described with reference to the drawings. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without impairing the gist of the present invention.

<Polarizing film>
1 (a) is a schematic plan view showing an example of the polarizing film of the present invention, and FIG. 1 (b) is a sectional view taken along line XX of FIG. 1 (a). The polarizing film 1 of the present 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 distinguished by the value of the luminosity factor correction polarization degree (Py), and these at least two regions have different contents of the dichroic dye. The polarizing film 1 has a liquid crystal layer 11, but may further have a base material layer 13, an alignment layer 12, and other layers. The polarizing film 1 shown in FIG. 1B shows 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 layer are provided on both sides of the base material layer 13. You may be doing it. The structures of the liquid crystal layers provided on both sides of the base material layer 13 may be the same as each other or may be different from each other.

The polarizing film 1 may be a long polarizing film having a length of 10 m or more, and in this case, the polarizing film 1 can be a wound body wound in a roll shape. A process such as continuously feeding out a polarizing film from this wound body, laminating it with a retardation layer described later, or cutting it into a single sheet can be performed. The length of the long polarizing film to be the wound body is not particularly limited as long as it is 10 m or more, but it can be, for example, 10000 m or less.

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

The region of the liquid crystal layer 11 containing the dichroic dye and the liquid crystal compound and in which the dichroic dye and the liquid crystal compound are horizontally oriented with respect to one surface of the polarizing film is the liquid crystal orientation horizontal direction with respect to light having a wavelength of λ nm. The dichroism ratio (= A1 (λ) / A2 (λ)), which is the ratio of the absorbance A1 (λ) and the absorbance A2 (λ) in the direction perpendicular to the liquid crystal orientation plane, is preferably 7 or more, preferably 20 or more. More preferably, it is more preferably 30 or more. The higher this value is, the more the polarization characteristic is excellent in absorption selectivity. Although it depends on the type of dichroic dye, when the liquid crystal layer 11 is a nematic liquid crystal phase, the above ratio is about 5 to 10. When the liquid crystal layer 11 is a nematic liquid crystal phase and a smectic liquid crystal phase described later, the fact that the liquid crystal compound and the dichroic dye are not phase-separated means that, for example, surface observation with various microscopes or scattering degree measurement with a haze meter Can be confirmed by.

As shown in FIGS. 1A and 1B, the liquid crystal layer 11 has a first region 11a and a first region 11a and a first region which are distinguished by the luminosity factor correction polarization degree (Py) and the content of the dichroic dye. It has two regions 11b. The polarizing film 1 shown in FIG. 1 (a) shows an example in which each of the two regions having different luminosity factor correction polarization degree (Py) and dichroic dye content is provided. Each of the second regions may have two or more regions, and may have three or more regions in which the contents of the dichroic dyes are different from each other.

The first region 11a of the polarizing film 1 shown in FIG. 1A contains a liquid crystal compound and a dichroic dye. The second region 11b contains a liquid crystal compound, but the dichroic dye may or may not be contained. When the dichroic dye is contained, the content of the dichroic dye is contained in the first region 11a. It is preferably less than the content of the dichroic pigment.

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

The first region 11a is preferably a region having high polarization characteristics, for example, the luminosity factor correction polarization degree (Py) can be 90% or more, preferably 92% or more, and 95% or more. More preferably, it is usually 100% or less. Further, in the first region 11a, the luminosity factor correction single transmittance (Ty) can be set to, for example, 35% or more, preferably 40% or more, more preferably 44% or more, and usually 50%. Is less than.

The second region 11b is preferably a low polarization region having a luminosity factor correction polarization degree (Py) lower than the luminosity factor correction polarization degree (Py) of the first region 11a. The luminosity factor correction polarization degree (Py) of the second region 11b can be, for example, 10% or less, preferably 5% or less, more preferably 1% or less, and even 0%. Good. Further, it is preferable that the second region 11b has a luminosity factor correction single transmittance (Ty) higher than the luminosity factor correction single transmittance (Ty) of the first region 11a. In the second region 11b, the luminosity factor correction simple substance transmittance (Ty) can be set to, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and usually 98% or less. is there.

The luminosity factor correction polarization degree (Py) and the luminosity factor correction unit transmittance (Ty) in the present specification can be calculated based on the polarization degree and the unit transmittance measured using a spectrophotometer. For example, the transmittance of the transmittance range transmission axis direction of the wavelength 380nm~780nm is visible light (alignment vertical) _{(T 1)} and the absorption axis direction (oriented the same direction) to _{(T 2),} the spectrophotometer It can be measured by the double beam method using a device in which a folder with a polarizer is set. For the degree of polarization and single transmittance in the visible light range, the degree of polarization and single transmittance at each wavelength are calculated using the following equations (Equation 1) and (Equation 2), and further, the two-degree field of view (C) of JIS Z 8701. By performing the luminosity factor correction with the light source), it can be calculated by the luminosity factor correction single transmittance (Ty) and the luminosity factor correction polarization degree (Py).

Polarization degree [%] = {(T _1- T ₂ ) / (T ₁ + T ₂ )} x 100 (Equation 1)
Elemental transmittance [%] = (T ₁ + T ₂ ) / 2 (Equation 2)

The occupied area of the first region 11a and the occupied area of the second region 11b may be appropriately selected according to the characteristics required for 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 more preferably 99% or more. Is even more preferable. Further, the occupied area of the first region 11a is preferably 50% or more, more preferably 70% or more, with respect to the total area occupied by the first region 11a and the second region 11b. It is preferably 80% or more, and more preferably 80% or more. For example, as shown in FIG. 1A, the occupied area of the second region 11b may be smaller than the occupied area of the first region 11a, and the first region 11a may be provided so as to surround the second region 11b. In the polarizing film 1 shown in FIG. 1A, the first region 11a is provided so as to surround one circular second region 11b, but a plurality of the second regions 11b 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. 1A, when the first region 11a is provided so as to surround the second region 11b, the second region 11a is provided. 11b can be formed into any shape such as a circular shape; an elliptical shape; an oval shape; a polygon such as a triangle, a square, a rectangle, and a rhombus; a character shape; and a combination thereof.

The second region 11b preferably has a circular, elliptical, oval, or polygonal shape in a plan view. 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 elliptical or oval, its long axis 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 a polygon, the diameter of the virtual circle drawn so that the polygon is inscribed is preferably 5 cm or less, more preferably 3 cm or less, and 2 cm or less. Is even more preferable. The second region 11b having the above-mentioned shape can be suitably used as a region corresponding to the lens position of a camera provided on a smartphone, tablet, or the like. At this time, the second region 11b is set to a region in which the luminosity factor correction polarization degree (Py) is 10% or less and the luminosity factor correction single transmittance (Ty) is 80% or more. It is possible to improve the performance of the camera because it is possible to reduce the coloring of the camera and obtain excellent transparency.

Further, the first region 11a and the second region 11b may be provided so that the plan view shape is linear, strip-shaped, wave-shaped, or the like, respectively. 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 each independently preferably 1 μm to 10 mm, more preferably 1 μm to 1 mm, and even more preferably 1 μm to 100 μm.

When the polarizing film is a long polarizing film, the long polarizing film is usually cut to a predetermined size according to the application of the polarizing film, so that the polarizing film is placed at a predetermined position after cutting. It is preferable to set the arrangement of the first region 11a and the second region 11b in the elongated polarizing film so that the first region 11a and the second region 11b are formed. For example, when the polarizing film after cutting is the polarizing film 1 shown in FIG. 1A, a plurality of second regions at predetermined intervals in the length direction and / or width direction of the elongated polarizing film. It is preferable to provide 11b.

The thickness of the first region 11a in the liquid crystal layer 11 is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 5 μm or less, and more preferably 3 μm or less. The thickness of the second region 11b in the liquid crystal layer 11 is preferably the same as that of the first region 11a, preferably 0.5 μm or more, more preferably 1 μm or more, and 5 μm or less. It is preferably 3 μm or less, and more preferably 3 μm or less. The thickness of the liquid crystal layer 11 can be measured with an interference film thickness meter, a laser microscope, a stylus type 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, and 1 μm or less. It is more preferably present, and further preferably 0.5 μm or less. By making the thicknesses of the first region 11a and the second region 11b of the liquid crystal layer 11 about the same and reducing the step between the first region 11a and the second region 11b, the liquid crystal layer 11 has a retardation layer and others described later. When the layers (surface protection layer, etc.) are laminated, problems such as the inclusion of air bubbles and the generation of wrinkles can be suppressed. Further, when the polarizing film 1 having the liquid crystal layer 11 is wound in a roll shape, problems such as winding marks being formed can be suppressed.

(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 disk-shaped liquid crystal compound, and a mixture thereof can be used. Further, 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, it is preferable to use a polymerizable liquid crystal compound. By using the polymerizable liquid crystal compound, the hue of the polarizing film can be arbitrarily controlled, and the polarizing film can be made significantly thinner. Further, since the polarizing film can be produced without performing the stretching treatment, it is possible to obtain a non-stretchable polarizing film without stretching relaxation due to heat.

The polymerizable liquid crystal compound means a compound having a polymerizable group and having liquid crystallinity. The polymerizable group means a group involved in the polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in the polymerization reaction by an active radical, an acid, or the like generated from a photopolymerization initiator described later. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxylanyl group, an oxetanyl group and the like. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group or an oxetanyl group is preferable, and an acryloyloxy group is more preferable. The liquid crystal property may be a thermotropic liquid crystal or a riotropic liquid crystal, but when mixed with a dichroic dye as in the liquid crystal layer of the present 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 showing a nematic liquid crystal phase or a thermotropic liquid crystal compound showing a smectic liquid crystal phase. When the liquid crystal layer 11 exhibits a polarization function as a polymer film obtained by a polymerization reaction, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and from the viewpoint of high performance, higher-order smectic. More preferably, it is a phase. Among them, higher-order smectic liquid crystal compounds forming smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase or smectic L phase More preferably, a higher-order smectic liquid crystal compound forming a smectic B phase, smectic F phase or smectic I phase is further preferable. When the liquid crystal layer 11 formed by the polymerizable liquid crystal compound is in these higher-order smectic phases, a region having higher polarization performance can be formed in the liquid crystal layer 11. Further, in such a region having high polarization performance, a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase can be obtained in X-ray diffraction measurement. The Bragg peak is a peak derived from the periodic structure of molecular orientation, and a film having a periodic interval of 3 to 6 Å can be obtained. In the polarizing film 1 of the present embodiment, it is preferable that the liquid crystal layer 11 contains a polymer in which the polymerizable liquid crystal compound is polymerized in the smectic phase, so that, for example, higher polarization characteristics can be imparted to the first region 11a.

Whether or not the polymerizable liquid crystal compound exhibits a nematic liquid crystal phase or a smectic liquid crystal phase can be confirmed, for example, as follows. After the composition for forming a polarizing film is applied to a base material to form a coating film, the solvent contained in the coating film is removed by heat treatment under the condition that the polymerizable liquid crystal compound does not polymerize. Subsequently, the liquid crystal phase developed by heating the coating film formed on the substrate to an isotropic phase temperature and gradually cooling it is inspected by texture observation with a polarizing microscope, X-ray diffraction measurement, or differential scanning calorimetry. To do.

Specifically, such a polymerizable liquid crystal compound has the following formula (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, wherein the divalent aromatic group is used. Alternatively, the hydrogen atom contained in the divalent alicyclic hydrocarbon group is 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, or a cyano group. Alternatively, it may be substituted with a nitro group, and the carbon atom constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom or a nitrogen atom. .. However, at least one of X ¹ , X ² and X ³ is a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. Is.
Y ¹ , Y ² , W ¹ and W ² are independent, single-bonded or divalent linking groups.
V ¹ and V ² represent an alkanediyl group having 1 to 20 carbon atoms which may have a substituent independently of each other, and −CH ₂ − constituting the alkanediyl group is −O−, −. It may be replaced with S- or NH-.
U ¹ and U ² represent a polymerizable group or a hydrogen atom independently of each other, and at least one is a polymerizable group. ]
Examples thereof include a compound represented by (hereinafter, may be referred to as compound (A)).

In compound (A), at least one of X ¹ , X ² and X ³ may have a substituent, a 1,4-phenylene group, or a cyclohexane, which may have a substituent. It is a 1,4-diyl group. In particular, X ¹ and X ³ are preferably cyclohexane-1,4-diyl groups which may have a substituent, and the cyclohexane-1,4-diyl group is trans-cyclohexane-. It is more preferably a 1,4-diyl group. When it contains a trans-cyclohexane-1,4-diyl group structure, smectic liquid crystallinity tends to be easily developed. Further, the substituents arbitrarily contained in the 1,4-phenylene group which may have a substituent and the cyclohexane-1,4-diyl group which may have a substituent include a methyl group and an ethyl. Examples thereof include an alkyl group having 1 to 4 carbon atoms such as a group or a butyl group, and a halogen atom such as a cyano group, a chlorine atom or a fluorine atom. It is preferably unsubstituted.

Y ¹ and ^{Y 2,} independently of one another, a single _{bond, -CH 2 CH 2 -, -} CH 2 O -, - COO -, - OCO -, - N = N -, - CR a = CR b -, - C≡C- or ^CR a = N-are preferred, ^{R a} and ^{R b} 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 X ¹ , X ² and X ³ all contain cyclohexane-1,4-diyl groups. If not, it is more preferable that Y ¹ and Y ² have different bonding methods. When Y ¹ and Y ² have different bonding methods, smectic liquid crystallinity tends to be easily exhibited.

W ¹ and W ² are preferably single-bonded, -O-, -S-, -COO- or OCO- independently of each other, and more preferably single-bonded or -O- independently of each other.

Examples of the alkanediyl group having 1 to 20 carbon atoms represented by V ¹ and V ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, and a butane-1,4. -Diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decan-1,10-diyl group, tetradecane Examples thereof include a -1,14-diyl group or an icosan-1,20-diyl group. V ¹ and V ² are preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably a linear alkanediyl group having 6 to 12 carbon atoms. By using a linear alkanediyl group having 6 to 12 carbon atoms, the crystallinity is improved and the smectic liquid crystallinity tends to be easily exhibited.

Examples of the substituent arbitrarily contained in the alkanediyl group having 1 to 20 carbon atoms which may have a substituent include a cyano group and a halogen atom such as a chlorine atom and a fluorine atom. The alkanediyl group is a substituent. , It is preferable that it is unsubstituted, and it is more preferable that it is an unsubstituted and linear alkanediyl group.

Both U ¹ and U ² are preferably polymerizable groups, and more preferably both photopolymerizable groups. Since the polymerizable liquid crystal compound having a photopolymerizable group can be polymerized under lower temperature conditions than the thermally polymerizable group, it is advantageous in that a polymer of the polymerizable liquid crystal compound can be formed in a state of high 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, an acryloyloxy group, a methacryloyloxy group, an oxylanyl group, an oxetanyl group and the like. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group or an oxetanyl group is preferable, and a methacryloyloxy group or an acryloyloxy group is more preferable.

Examples of such polymerizable liquid crystal compounds include the following.

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

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

Compound (A) can be described, for example, in Lubet all. Recl. Trav. Chim. It can be produced by a known method described in Pays-Bas, 115, 321-328 (1996), Japanese Patent No. 4719156, and the like.

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 60 parts by mass with respect to 100 parts by mass of the solid content of the liquid crystal layer 11. Is 70 to 98 parts by mass, more preferably 80 to 97 parts by mass. When the content of the polymerizable liquid crystal compound is within the above range, the orientation tends to be high. Here, the solid content refers to the total amount of the components excluding the solvent from the composition for forming a polarizing layer, which will be described later.

(Dichroic pigment)
The dichroic dye refers to a dye having a property in which the absorbance in the major axis direction and the absorbance in the minor axis direction of the molecule are different. The dichroic dye is a dye that is oriented together with the liquid crystal compound to exhibit dichroism, and the dichroic dye itself may have polymerizable property or may have liquid crystal property. The dichroic dye preferably has a property of absorbing visible light, and more preferably has a maximum absorption wavelength (λ _MAX ) in the range of 380 to 680 nm. Examples of such a bicolor dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, an anthraquinone dye, and the like, and among them, the azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye, a stilbene azo dye, and the like, and a bisazo dye or a trisazo dye is preferable. The dichroic dye may be used alone or in combination of two or more, but in order to obtain absorption in the entire visible light range, it is preferable to combine three or more kinds of dichroic dyes. It is more preferable to combine more than one kind of azo dye.

Examples of the azo dye include the formula (I).
T ¹ −A ¹ (−N = N−A ² ) _p −N = N−A ³ −T ² (I)
[In formula (I), A ¹ , A ² and A ³ are independent of each other and may have a substituent, a 1,4-phenylene group, a naphthalene-1,4-diyl group, or a substituent. a heterocyclic group which may be divalent to have a, T ¹ and T ² is an electron withdrawing group or electron releasing groups independently of each other, the position of substantially 180 ° relative to the azo bond plane Have in. p represents an integer from 0 to 4. When p is 2 or more, each A ² may be the same or different from each other. The -N = N-bond may be replaced with a -C = C-, -COO-, -NHCO- or -N = CH- bond within the range showing absorption in the visible region. ]
Examples thereof include a compound represented by (hereinafter, also referred to as “compound (I)”).

Examples of the substituent arbitrarily contained in the 1,4-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ¹ , A ² and A ³ include a methyl group, an ethyl group and a butyl group. Alkyl group having 1 to 4 carbon atoms; alkoxy group having 1 to 4 carbon atoms such as methoxy group, ethoxy group or butoxy group; alkylfluoric group having 1 to 4 carbon atoms such as trifluoromethyl group; cyano group; nitro group Halogen atoms such as chlorine atom and fluorine atom; Substituent or unsubstituted amino group such as amino group, diethylamino group and pyrrolidino group (Substituent amino group is amino having one or two alkyl groups having 1 to 6 carbon atoms. It means an amino group in which a group or two substituted alkyl groups are bonded to each other to form an alcandiyl group having 2 to 8 carbon atoms. The unsubstituted amino group is -NH ₂ ). Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a hexyl group and the like. The alkanediyl group having 2 to 8 carbon atoms includes an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. , Hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group and the like. In order to include compound (I) in a highly ordered liquid crystal structure such as smectic liquid crystal, A ¹ , A ² and A ³ were independently substituted with each other and hydrogen was substituted with a methyl group or a methoxy group. A 1,4-phenylene group or a divalent heterocyclic group is preferable, and p is preferably 0 or 1. Among them, p is 1, and at least two of the three structures A ¹ , A ² and A ³ are 1,4-phenylene groups, which has both simplicity of molecular synthesis and high performance. More preferred.

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. When A ² is a divalent heterocyclic group, a structure in which the molecular binding angle is substantially 180 ° is preferable, and specifically, benzothiazole, benzimidazole, and benzoxazole in which two 5-membered rings are condensed are preferable. The structure is more preferred.

It is preferable that T ¹ and T ² are electron attracting groups or electron emitting groups independently of each other and have different structures, and T ¹ is an electron attracting group and T ² is an electron emitting group, or It is more preferable that T ¹ is an electron emitting group and T ² is an electron attracting group. Specifically, T ¹ and T ² independently contain one alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, and an alkyl group having 1 to 6 carbon atoms. Alternatively, it is preferably an amino group having two amino groups, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms, or a trifluoromethyl group, and among them, a smectic liquid crystal. In order to be included in such a highly ordered liquid crystal structure, it is necessary to have a structure having a smaller exclusion volume of molecules. Therefore, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a cyano group , An amino group having one or two alkyl groups having 1 to 6 carbon atoms, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms is preferable.

Examples of such an azo dye include the following.

[In formulas (2-1) to (2-6), B ^{1 to} B ²⁰ are independent of each other, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a cyano group. Represents a nitro group, a substituted or unsubstituted amino group (the definition of a substituted amino group and an unsubstituted amino group is as described above), a chlorine atom or a trifluoromethyl group. Further, from the viewpoint of obtaining high polarization performance, B ² , B ⁶ , B ⁹ , B ¹⁴ , B ¹⁸ and B ¹⁹ are preferably hydrogen atoms or methyl groups, and more preferably hydrogen atoms.
n1 to n4 each independently represent an integer of 0 to 3.
If n1 is 2 or more, to each of a plurality of B ² may be the same or different,
If n2 is 2 or more, to each of the plurality of B ⁶ may be the same or different,
If n3 is 2 or more, to each of the plurality of B ⁹ may be the same or different,
When n4 is 2 or more, the plurality of B ^14s may be the same or different.

As the anthraquinone dye, a compound represented by the formula (2-7) is preferable.

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

As the oxazine dye, a compound represented by the formula (2-8) is preferable.

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

As the acridine dye, a compound represented by the formula (2-9) is preferable.

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

The alkyl group having 1 to 4 carbon atoms represented by R ^x in the formula (2-7), the formula (2-8) and the formula (2-9) includes a methyl group, an ethyl group, a propyl group and a butyl group. , Pentyl group, hexyl group and the like, and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a toluyl group, a xsilyl group and a naphthyl group.

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

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

ｎ５は１〜３の整数を表す。］

n5 represents an integer of 1 to 3. ]

ｎ６は１〜３の整数を表す。］[In formula (2-11), D ³ and D ⁴ represent groups represented by any of formulas (2-11a) to (2-11h) independently of each other.

n6 represents an integer of 1 to 3. ]

The content of the dichroic dye (the ratio of the total amount when a plurality of types are contained) is the degree of polarization corrected for luminosity factor (as in the first region 11a of the liquid crystal layer 11) from the viewpoint of obtaining good light absorption characteristics. In the region where Py) has a high polarization characteristic of 90% or more, it is usually preferably 0.1 to 30 parts by mass, and more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. It is preferably 3 to 15 parts by mass, and more preferably 3 to 15 parts by mass. If the content of the dichroic dye is less than this range, light absorption becomes insufficient and sufficient polarization performance cannot be obtained, and if it is more than this range, the orientation of the liquid crystal molecules may be hindered. In a region having a low polarization characteristic of 10% or less of the luminosity factor correction polarization degree (Py), such as the second region 11b of the liquid crystal layer 11, the amount is usually 0 to 20 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. It is preferably 0 to 10 parts by mass, and further preferably 0 to 5 parts by mass.

(Base layer)
The polarizing film 1 may have a base material layer 13. The base material layer 13 can be used to support the alignment layer 12 and the polarizing layer 21 described later when producing the polarizing film 1, for example, as will be described later, and the liquid crystal layer 11 of the polarizing film 1 can be used. It can be used to support.

The base material layer 13 may be a glass base material or a resin base material, but is preferably a resin base material. Further, from the viewpoint that the polarizing film 1 can be continuously produced, it is more preferable that the base material layer 13 is a roll-shaped long resin base material unwound. The resin base material is preferably a base material having a translucent property capable of transmitting visible light. Here, the translucency means that the luminosity factor correction simple substance transmittance is 80% or more with respect to the light in the wavelength range of 380 to 780 nm.

The thickness of the base material layer 13 is preferably thin in that it has a mass sufficient for practical handling, but if it is too thin, the strength tends to decrease and the processability tends to be inferior. The thickness of the base material layer 13 is usually 5 μm to 300 μm, preferably 20 μm to 200 μm. Further, the base material layer 13 may be provided so as to be peelable. For example, after the liquid crystal layer 11 of the polarizing film 1 is bonded to a member forming a display device, a retardation layer described later, or the like, the polarizing film 1 It may be peelable from. As a result, a further thinning effect of the polarizing film 1 can be obtained.

Examples of the resin constituting the resin base material include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; triacetyl cellulose and diacetyl. Cellulose esters such as cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide; and the like can be mentioned.

Examples of commercially available cellulose ester resin base materials include "Fujitack Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (manufactured by Konica Minolta Opto Co., Ltd.). ..

Commercially available cyclic olefin resins include "Topas" (registered trademark) (Ticona (Germany)), "Arton" (registered trademark) (JSR Corporation), "ZEONOR" (registered trademark), Examples thereof include "ZEONEX" (registered trademark) (above, manufactured by Nippon Zeon Corporation) and "Apel" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such a cyclic olefin resin can be formed into a film by a known means such as a solvent casting method and a melt extrusion method to obtain a resin base material. A commercially available resin base material of a cyclic olefin resin can also be used. As the resin base material of the commercially available cyclic olefin resin, "Scina" (registered trademark), "SCA40" (registered trademark) (all manufactured by Sekisui Chemical Industry Co., Ltd.), "Zeonoa film" (registered trademark) (Optes stock) Examples include "Arton Film" (registered trademark) (manufactured by JSR Corporation).

The base material layer 13 may have a one-layer structure or a multi-layer structure having two or more layers. When the base material layer 13 has a multi-layer structure, each layer may be formed of the same material or may be formed of different materials.

Further, the base material layer 13 may have a 1/4 wave plate function. Since the base material layer 13 has a 1/4 wave plate function, a polarizing film having a function of a circular polarizing plate can be obtained by combining the base material layer 13 and the liquid crystal layer 11. As a result, a circular polarizing plate can be obtained without attaching a retardation layer having a 1/4 wave plate function to the polarizing film 1 separately from the base material layer 13. When the base material layer 13 has a multi-layer structure, a layer having a 1/2 wave plate function and a layer having a 1/4 wave plate function are laminated, and the liquid crystal layer 11 is a 1/2 wave plate. A circular polarizing plate can be obtained by laminating on the layer side having a function. Alternatively, when the base material layer 13 has a multilayer structure, a circular polarizing plate can also be used by using a layer in which a layer having a 1/4 wave plate function of inverse wavelength dispersion and a layer having a positive C plate function are laminated. Can be obtained.

(Orientation layer)
The polarizing film 1 may have an alignment layer 12 on the base material layer 13, and the alignment layer 12 is arranged between the base material layer 13 and the liquid crystal layer 11. The alignment layer 12 can have an orientation regulating force for aligning the liquid crystal compound in the liquid crystal layer 11 laminated on the liquid crystal layer 11 in a desired direction.

The alignment layer 12 facilitates liquid crystal orientation of the liquid crystal compound. The state of liquid crystal orientation such as horizontal orientation, vertical orientation, hybrid orientation, and inclined orientation changes 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 that expresses horizontal orientation as an orientation regulating force, the liquid crystal compound can form horizontal orientation or hybrid orientation, and if the alignment layer 12 is a material that expresses vertical orientation, the liquid crystal is liquid crystal. The compound can form a vertical or tilted orientation. The expressions such as horizontal and vertical represent the direction of the long axis of the oriented liquid crystal compound with respect to one plane of the polarizing film. For example, vertical orientation means having a long axis of a polymerizable liquid crystal oriented in a direction perpendicular to one plane of the polarizing film. The term "perpendicular" as used herein means 90 ° ± 20 ° with respect to one plane of the polarizing film. Since the polarizing film 1 preferably has the polarization characteristics of the plane of the polarizing film 1, the alignment layer 12 is preferably formed by using a material that exhibits horizontal orientation.

The orientation regulating force of the alignment layer 12 can be arbitrarily adjusted depending on the surface condition and rubbing conditions when the alignment layer 12 is formed of the alignment polymer, and when the alignment layer 12 is formed of the photoalignment polymer. Can be arbitrarily adjusted depending on the polarization irradiation conditions and the like. Further, the liquid crystal orientation can be controlled by selecting physical properties such as surface tension and liquid crystal property 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. Further, the alignment layer 12 formed between the base material layer 13 and the liquid crystal layer 11 is insoluble in the solvent used when forming the liquid crystal layer 11 on the alignment layer 12, and also removes the solvent. Those having heat resistance in the heat treatment for the orientation of the liquid crystal are preferable.

Examples of the alignment layer 12 include an alignment film made of an alignment polymer, a photo-alignment film, a group alignment film, and the like. When the base material layer 13 is unwound from a long roll-shaped resin base material, the alignment layer 12 is preferably a photo-alignment film from the viewpoint that the orientation direction thereof can be easily controlled.

Examples of the oriented polymer include polyamides and gelatins having an amide bond in the molecule, polyimide having an imide bond in the molecule, polyamic acid, which is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, and polyoxazole. Examples thereof include polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters. Of these, polyvinyl alcohol is preferable. These oriented polymers may be used alone or in combination of two or more.

In the alignment film made of an oriented polymer, a composition in which the oriented polymer is dissolved in a solvent (hereinafter, may be referred to as "oriented polymer composition") is applied to the base material layer 13 to remove the solvent. Alternatively, it can be obtained by applying an oriented polymer composition to the base material layer 13, removing the solvent, and rubbing (rubbing method).

Solvents used in the oriented polymer composition include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve or propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl. Ester solvents such as ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate or ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methylamyl ketone or methyl isobutyl ketone; fats such as pentane, hexane or heptane Group hydrocarbon solvents; aromatic hydrocarbon solvents such as toluene or xylene, nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran or dimethoxyethane; chlorine-substituted hydrocarbon solvents such as chloroform or chlorobenzene; and the like. These solvents may be used alone or in combination of two or more.

The content of the oriented polymer in the oriented polymer composition may be within a range in which the oriented polymer can be completely dissolved in the solvent, but is preferably 0.1 to 20% by mass in terms of solid content with respect to the solution. 0.1 to 10% by mass is more preferable.

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

Examples of the method for applying the oriented polymer composition to the base material layer 13 include a coating method such as a spin coating method, an extrusion method, a gravure coating method, a die coating method, a bar coating method or an applicator method, and a flexographic method. Known methods such as a printing method can be mentioned. When the polarizing film 1 is manufactured by a continuous manufacturing method of the Roll-to-Roll format, a printing method such as a gravure coating method, a die coating method, or a flexographic method can be usually adopted as the coating method.

By removing the solvent contained in the oriented polymer composition, a dry film of the oriented polymer is formed. Examples of the solvent removing method include a natural drying method, a ventilation drying method, a heat drying method, and a vacuum drying method. After that, the dry film can be brought into contact with a rotating rubbing roll around which the rubbing cloth is wound to form the alignment layer 12.

The photoalignment film is usually coated with a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter, may be referred to as "composition for forming a photoalignment film") on the base material layer 13. It can be obtained by irradiating the coating layer for the alignment layer formed in the above process with polarized light (preferably polarized UV). The photoalignment film is more preferable in that the direction of the orientation regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

A photoreactive group is a group that produces a liquid crystal orientation ability when irradiated with light. Specifically, it produces a photoreaction that is the origin of the liquid crystal orientation ability, such as a molecule orientation-inducing or isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction that occurs when light is irradiated. is there. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferable because they are excellent in orientation. As the photoreactive group capable of causing the above reaction, an unsaturated bond, particularly a double bond is preferable, and a carbon-carbon double bond (C = C bond) and a carbon-nitrogen double bond (C) are preferable. A group having at least one selected from the group consisting of (= N bond), nitrogen-nitrogen double bond (N = N bond), and carbon-oxygen double bond (C = O bond) is more preferable.

Examples of the photoreactive group having a C = C bond include a vinyl group, a polyene group, a stilbene group, a still bazol group, a still bazolium group, a chalcone group, a cinnamoyl group and the like. A chalcone group or a cinnamoyl group is preferable from the viewpoint of easy control of reactivity and expression of orientation regulating force at the time of photoalignment. 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 hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group or a formazan group, and those having an azoxibenzene as a basic structure. Examples of the photoreactive group having a C = O bond include a benzophenone group, a coumarin group, an anthraquinone group, a maleimide group and the like. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group or an alkyl halide group.

The solvent of the composition for forming a photoalignment film is preferably one that dissolves a polymer and a monomer having a photoreactive group, and the solvent is, for example, a solvent listed as the solvent of the orientation polymer composition. Can be mentioned.

The content of the polymer or monomer having a photoreactive group in the composition for forming a photo-aligning film is appropriately adjusted according to the type of the polymer or monomer having a photo-reactive group and the thickness of the photo-aligning film to be produced. However, it is preferably 0.2% by mass or more, and particularly preferably 0.3 to 10% by mass. Further, a polymer material such as polyvinyl alcohol or polyimide or a photosensitizer may be contained as long as the characteristics of the photoalignment film are not significantly impaired.

Examples of the method of applying the composition for forming a photoalignment film to the base material layer 13 include the same method as the method of applying the above-mentioned orientation polymer composition to the base material layer 13. Examples of the method for removing the solvent from the coated composition for forming a photoalignment film include the same method as the method for removing the solvent from the oriented polymer composition.

The polarized light irradiation may be performed directly on the dry film obtained by removing the solvent from the photoalignment film forming composition coated on the base material layer 13, and the polarized light transmitted through the base material layer 13 irradiates the dry film. It may be done from the base material layer 13 side so as to be done. Further, it is particularly preferable that the polarized light used for the polarized light irradiation is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in the wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferable. Examples of the light source used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, ultraviolet light lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high pressure mercury lamps or metal halide lamps are more preferable. .. These lamps are preferable because they have a high emission intensity of ultraviolet light having a wavelength of 313 nm. Polarized light can be irradiated by irradiating light from a light source through an appropriate polarizer. As such a polarizing element, a polarizing filter, a polarizing prism such as Gran Thomson or Gran Tailor, or a wire grid type polarizer can be used.

If masking is performed during rubbing or polarized light irradiation, it is possible to form a plurality of regions (patterns) in which the directions of liquid crystal orientation are different.

The groove alignment film is a film having an uneven pattern or a plurality of grooves on the surface of the film. When liquid crystal molecules are placed on a film having a plurality of linear grubs arranged at equal intervals, the liquid crystal molecules are oriented in the direction along the grooves.

As a method of obtaining a grub alignment film, a method of forming an uneven pattern by performing exposure and rinsing treatment after exposure through an exposure mask having a pattern-shaped slit on the surface of a photosensitive polyimide film, or a plate having a groove on the surface. A method of forming a layer of UV curable resin before curing on a shaped master, transferring the resin layer to a substrate and then curing, and a plurality of films of UV curable resin before curing formed on the substrate. Examples thereof include a method in which a roll-shaped master having a groove is pressed to form irregularities and then cured. Specific examples thereof include the methods described in JP-A-6-34976 and JP-A-2011-242743.

In order to obtain an orientation with little alignment disorder, the width of the convex portion of the grub alignment film is preferably 0.05 μm to 5 μm, and the width of the concave portion is preferably 0.1 μm to 5 μm. The depth is preferably 2 μm or less, and preferably 0.01 μm to 1 μm or less.

(Other layers)
The polarizing film 1 may have a layer other than the base material layer 13 and the alignment layer 12. For example, a surface protective layer for the purpose of protecting the surface of the liquid crystal layer 11 may be provided on the surface of the liquid crystal layer 11 opposite to the base material layer 13. Further, when the base material layer 13 is peeled off and used, a surface protective layer may be provided on the surface of the liquid crystal layer 11 on the side where the base material layer 13 is peeled off. The surface protective layer may have a one-layer structure or a multi-layer structure. When the surface protective layer has a multi-layer structure, each layer may be formed of the same material or may be formed of different materials.

<Circular polarizing plate>
2 (a) to 2 (c) are schematic cross-sectional views showing an example of the circular polarizing plate of the present invention, respectively. The polarizing film 1 shown in FIG. 1 (b) is formed into circular polarizing plates 5a and 5b shown in FIGS. 2 (a) and 2 (b) by laminating a retardation layer 15 having a 1/4 wave plate function. Can be done. The retardation layer 15 may be laminated on the liquid crystal layer 11 side of the polarizing film 1 (FIG. 2 (a)) or on the substrate layer 13 side (FIG. 2 (b)). Further, the circular polarizing plate 5a shown in FIG. 2A from which the base material layer 13 is peeled off can also be used as the circular polarizing plate 5c (FIG. 2C). In this case, the orientation is aligned with the base material layer 13. The layer 12 may also be peeled off.

Further, the circular polarizing plate may be a laminate of the polarizing film 1 and the retardation layer having a multilayer structure. In this case, as the retardation layer having a multilayer structure, a retardation layer in which a layer having a 1/2 wave plate function and a layer having a 1/4 wave plate function are laminated can be used, and the retardation layer having a multilayer structure can be used. A circular polarizing plate can be obtained by laminating the layer side having the 1/2 wave plate function and the polarizing film 1. Alternatively, a circular polarizing plate can also be obtained by using a retardation layer in which a layer having a 1/4 wave plate function of inverse wavelength dispersion and a layer having a positive C plate function are laminated as a retardation layer having a multilayer structure. be able to.

Further, the base material layer 13 of the polarizing film 1 may be one having a function as a retardation layer, and the retardation layers may be further laminated to form a circular polarizing plate. In this case, the function of the base material layer 13 and the retardation layer as a retardation layer may be selected according to the stacking position of the base material layer 13 and the retardation layer in the circular polarizing plate.

The polarizing film and the retardation layer can be laminated via an adhesive layer using a known pressure-sensitive adhesive or an adhesive.

<Manufacturing method of polarizing film (first manufacturing method)>
3 (a) to 3 (d) are schematic cross-sectional views showing a layer structure obtained in each step of the manufacturing process of the polarizing film 1 shown in FIG. 1 (b). The first method for producing the polarizing film 1 is
A preparatory step of preparing a laminated film 62 (FIG. 3 (b)) having a polarizing layer 21 containing a liquid crystal compound and a dichroic dye on at least one side of the base material layer 13.
By contacting a part of the polarizing layer 21 of the laminated film 62 with a liquid material capable of reducing the content of the dichroic dye in the polarizing layer 21, the dichroic dye is brought into contact with a part of the polarizing layer 21. It has a liquid material contacting step of reducing the content of.

The liquid material contacting step involves laminating a protective layer 35 having a coating region 35a for coating the polarizing layer 21 and an exposed region 35b for exposing the polarizing layer 21 on the polarizing layer 21 of the laminated film 62. A protective layer laminating step of obtaining a laminated film 63 with a protective layer (FIG. 3C), and
By contacting the laminated film 63 with a protective layer with a liquid material that can reduce the content of the dichroic dye in the polarizing layer 21, the content of the dichroic dye is reduced in a part of the polarizing layer 21. Decolorization step of obtaining the decolorized laminated film 64 (FIG. 3 (d)) and
It has a peeling step of peeling the protective layer 35 from the decolorized laminated film 64, whereby the polarizing film 1 shown in FIG. 1B can be manufactured.

(Preparation process)
The laminated film 62 prepared in the preparation step is not particularly limited as long as it has the polarizing layer 21 on at least one side of the base material layer 13, but is oriented on the base material layer 13 as shown in FIG. 3 (b). It is preferable that the layer 12 and the polarizing layer 21 are laminated in this order. In such a laminated film 62, a composition for forming an alignment layer is applied to one surface of the base material layer 13 to form the alignment layer 12, and the base material layer 61 with the alignment layer (FIG. 3A) is formed. The process of forming the alignment layer and the step of forming the polarizing layer 21 by applying the composition for forming the polarizing layer to the surface of the base layer 61 with the alignment layer on the side where the alignment layer 12 is formed are performed. Can be manufactured after.

In the alignment layer forming step, the base material layer 13 may be surface-treated before the alignment layer forming composition is applied. Examples of the surface treatment method include corona treatment, plasma treatment, laser treatment, ozone treatment, saponification treatment, flame treatment, coupling agent coating treatment, primer treatment and the like. As the alignment layer forming composition, the above-mentioned orientation polymer composition, a photo-alignment film forming composition, a composition containing a resin material for forming a grub alignment film, and the like can be used. The method for forming the alignment layer using each composition is also as described above. For example, when the alignment layer forming composition contains a photo-oriented polymer, the alignment layer forming step is performed by irradiating the alignment layer coating layer formed by coating the alignment layer forming composition with polarized light. , An orientation layer having an orientation regulating force can be formed in a predetermined direction.

The composition for forming a polarizing layer is a composition containing a liquid crystal compound and a dichroic dye, preferably containing a solvent and a polymerization initiator, such as a sensitizer, a polymerization inhibitor, a leveling agent, and a reactive additive. May include. As the liquid crystal compound and the dichroic dye, the above-mentioned ones can be used, and as the solvent, the polymerization initiator, the sensitizer, the polymerization inhibitor, the leveling agent, and the reactive additive, those described later can be used. ..

Examples of the method for coating the composition for forming a polarizing layer include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a slit coating method, a microgravure method, a die coating method, and an inkjet method. .. In addition, a method of coating using a coater 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 the Roll to Roll format, the coating method by the microgravure method, the inkjet method, the slit coating method, or the die coating method is preferable, and in the case of coating on a single-wafer substrate such as glass, the coating method is preferable. , A spin coating method having high uniformity is preferable. In the case of coating in the Roll to Roll format, the alignment film forming composition or the like is applied to the base material layer 13 to form the alignment layer 12, and the polarizing layer forming composition is further applied on the obtained alignment layer 12. It can also be applied continuously.

When the polarizing layer forming composition is applied to form the polarizing layer 21, the solvent is removed from the coated polarizing layer forming composition to form the polarizing layer coating layer. As a method for removing the solvent, the same method as the method for removing the solvent from the oriented polymer composition can be used, and examples thereof include natural drying, ventilation drying, heat drying, vacuum drying, and a method combining these. Be done. Of these, natural drying or heat drying is preferable. 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, more preferably 30 seconds to 5 minutes.

When the liquid crystal compound contained in the composition for forming a polarizing layer is a polymerizable liquid crystal compound, the coating layer for the polarizing layer formed in the polarizing layer forming step is irradiated with active energy rays to photopolymerize the polymerizable liquid crystal compound. Therefore, it is preferable to form the polarizing layer 21 as the polymer layer of the polymerizable liquid crystal compound. The active energy rays to be irradiated include the type of the polymerizable liquid crystal compound contained in the coating layer for the polarizing layer (particularly, the type of the photopolymerizable functional group contained in the polymerizable liquid crystal compound), and when the photopolymerization initiator is contained. It is appropriately selected according to the type of photopolymerization initiator and the amount thereof. Specifically, one or more kinds of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-ray, α-ray, β-ray, and γ-ray can be mentioned. Among them, ultraviolet light is preferable because it is easy to control the progress of the polymerization reaction and it is possible to use a photopolymerization apparatus widely used in the art, so that it can be polymerized by ultraviolet light. It is preferable to select the type of the sex liquid crystal compound.

Examples of the light source of the active energy ray include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excima laser, and a wavelength range of 380. Examples thereof include an LED light source that emits light of up to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

Irradiation intensity of the active energy rays are ^{usually, 10mW / cm 2 ~3000mW / cm} 2. The irradiation intensity of the active energy ray is preferably the intensity in the wavelength region effective for activating the cationic polymerization initiator or the radical polymerization initiator. The time for irradiating the active energy ray is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 5 minutes, more preferably 0.1 seconds to 3 minutes, and further preferably 0. It is 1 second to 1 minute. When irradiated once or multiple times with the irradiation intensity of such active energy rays, the integrated light amount is 10 mJ / cm ^{2 to} 3000 mJ / cm ² , preferably 50 mJ / cm ^{2 to} 2,000 mJ / cm ² , more preferably. it can be set to ^{100mJ / cm 2 ~1000mJ / cm 2} . If the integrated light intensity is less than this range, the polymerizable liquid crystal compound may not be sufficiently cured and good transferability may not be obtained. On the contrary, when the integrated light amount is equal to or more than this range, the polarizing layer may be colored.

(solvent)
The composition for forming a polarizing layer may contain a solvent. In general, a polymerizable liquid crystal compound has a high viscosity. Therefore, when a polymerizable liquid crystal compound is used as the liquid crystal compound, coating is facilitated by using a composition for forming a polarizing layer containing a solvent, and as a result, a polarizing layer is formed. It will be easier. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound and the bicolor dye, and is 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, ethylene glycol methyl ether acetate and γ-butyrolactone. Alternatively, an ester solvent such as propylene glycol methyl ether acetate or ethyl lactate; a ketone solvent such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone or methyl isobutyl ketone; an aliphatic hydrocarbon solvent such as pentane, hexane or heptane; toluene. Alternatively, an aromatic hydrocarbon solvent such as xylene, a nitrile solvent such as acetonitrile; an ether solvent such as tetrahydrofuran or dimethoxyethane; a chlorine-containing solvent such as chloroform or chlorobenzene; dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, Examples thereof include amide-based solvents such as 1,3-dimethyl-2-imidazolidinone. These solvents may be used alone or in combination of two or more.

The content of the solvent contained in the polarizing layer forming composition is preferably 50 to 98% by mass with respect to the total amount of the polarizing layer forming composition. In other words, the solid content in the polarizing layer forming composition is preferably 2 to 50% by mass. When the solid content is 50% by mass or less, the viscosity of the polarizing layer forming composition is low, so that the thickness of the polarizing layer 21 becomes substantially uniform, and the polarizing layer 21 tends to be less likely to be uneven. There is. Further, the content of such solid content 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 is a compound that can be used when a polymerizable liquid crystal compound is used as the liquid crystal compound and can initiate a polymerization reaction such as a polymerizable liquid crystal compound. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferable from the viewpoint that it does not depend on the phase state of the thermotropic liquid crystal.

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

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

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

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl). ) Butane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1 -[4- (2-Hydroxyethoxy) phenyl] propane-1-one, 1-hydroxycyclohexylphenylketone or 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane-1- Examples include on oligomers.

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

Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine and 2,4-bis (trichloromethyl) -6- (4-methoxy). Naftyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxystyryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (5-Methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (fran-2-yl) ethenyl] -1 , 3,5-Triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino-2-methylphenyl) ethenyl] -1,3,5-triazine or 2,4-bis (trichloromethyl) Methyl) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine and the like can be mentioned.

Commercially available polymerization initiators can also be used. Commercially available polymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, 369, 379, 127, 754, OXE01, OXE02, or OXE03 (manufactured by Ciba Specialty Chemicals Co., Ltd.). Sakeol (registered trademark) BZ, Z, or BEE (manufactured by Seiko Kagaku Co., Ltd.); kayacure (registered trademark) BP100, or UVI-6992 (manufactured by Dow Chemical Co., Ltd.); ADEKA PUTMER SP-152, N-1717, N-1919, SP-170, ADEKA ARCLUDS NCI-831, ADEKA ARCULDS NCI-930 (manufactured by ADEKA Corporation); TAZ-A or TAZ-PP (manufactured by Nippon Sibel Hegner Co., Ltd.); TAZ- 104 (manufactured by Sanwa Chemical Co., Ltd.); and the like. As the polymerization initiator in the composition for forming a polarizing layer, one kind may be used, or two or more kinds of a plurality of kinds of polymerization initiators may be mixed and used according to the light source of light.

The content of the polymerization initiator in the composition for forming a polarizing layer can be appropriately adjusted according to the type of the polymerizable liquid crystal compound and the amount thereof, but is usually 0% with respect to 100 parts by mass of the content of the polymerizable liquid crystal compound. It is 1 to 30 parts by mass, preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass. When the content of the polymerization initiator is within the above range, the polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

(Sensitizer)
The composition for forming a polarizing layer may contain a sensitizer. The sensitizer can be suitably 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 photosensitized. It is preferably an agent. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (eg, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene and anthracene compounds such as alkoxy group-containing anthracene (eg, dibutoxyanthracene, etc.). Examples include phenothiazine and rubrene.

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

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

Examples of the polymerization inhibitor include radical capture of hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (for example, butyl catechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxyradic and the like. Agents; thiophenols; β-naphthylamines, β-naphthols and the like.

When the composition for forming a polarizing layer contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.1 to 10 parts by mass, more preferably 0.1 part by mass, based on 100 parts by mass of the content of the polymerizable liquid crystal compound. It is 0.5 to 5 parts by mass, more preferably 0.5 to 3 parts by mass. When the content of the polymerization inhibitor is within the above range, the polymerization can be carried out 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 is an additive having a function of adjusting the fluidity of the composition and flattening the film obtained by applying the composition, for example, an organically modified silicone oil type, a polyacrylate type or a perfluoro. Examples thereof include alkyl leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all manufactured by Toray Dow Corning Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all of which are Momentive Performance Materials Japan LLC) (Manufactured by), Florinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Co., Ltd.), Megafuck (registered trademark) R-08 , R-30, R-90, F-410, F-411, F-443, F-445, F-470, F-477, F-479, F-482. , F-483 (all manufactured by DIC Co., Ltd.), Ftop (trade name) EF301, EF303, EF351, EF352 (all manufactured by Mitsubishi Materials Electronics Co., Ltd.), Surflon (registered) Trademarks) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.) , Trade name E1830, E5844 (manufactured by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 or BYK-361N (all trade names: manufactured by BM Chemie), etc. Can be mentioned. Of these, polyacrylate-based leveling agents or perfluoroalkyl-based leveling agents are preferable.

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 further preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the liquid crystal compound content. 0.1 to 3 parts by mass. When the content of the leveling agent is within the above range, it is easy to horizontally orient the liquid crystal compound, 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, the obtained polarizing layer tends to be uneven. The composition for forming a polarizing layer may contain two or more leveling agents.

(Reactive additive)
The composition for forming a polarizing layer may contain a reactive additive. As the reactive additive, those having a carbon-carbon unsaturated bond and an active hydrogen reactive group in the molecule are preferable. The "active hydrogen reactive group" referred to here is a group having reactivity with a group having active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH) and an amino group (-NH ₂ ). A typical example thereof is a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, and a maleic anhydride group. The number of carbon-carbon unsaturated bonds or active hydrogen reactive groups contained in the reactive additive is usually 1 to 20 each, and preferably 1 to 10 each.

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

The carbon-carbon unsaturated bond contained in the reactive additive may be a carbon-carbon double bond, a carbon-carbon triple bond, or a combination thereof, but is preferably a carbon-carbon double bond. Among them, the reactive additive preferably contains a carbon-carbon unsaturated bond as a vinyl group and / or a (meth) acrylic group. Further, a reactive additive in which the active hydrogen reactive group is at least one selected from the group consisting of an epoxy group, a glycidyl group and an isocyanate group is preferable, and a reactive additive having an acrylic group and an isocyanate group is more preferable. ..

Specific examples of the reactive additive include compounds having a (meth) acrylic group and an epoxy group such as methacryloxyglycidyl ether and acryloxiglycidyl ether; (meth) acrylic group and oxetane such as oxetan acrylate and oxetane methacrylate. Compounds with groups; Compounds with (meth) acrylic groups and lactone groups, such as lactone acrylates and lactone methacrylates; Compounds with vinyl and oxazoline groups, such as vinyl oxazoline and isopropenyl oxazoline; Isocyanatomethyl acrylates , Isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate and the like, oligomers of compounds having a (meth) acrylic group and an isocyanate group. Examples thereof include compounds having a vinyl group, a vinylene group and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride or vinyl maleic anhydride. Among them, metharoxyglycidyl ether, acryloxiglycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyl oxazoline, 2-isocyanato ethyl acrylate, 2-isocyanato ethyl methacrylate or the above oligomer is preferable, and isocyanato methyl acrylate, 2-Isocyanatoethyl acrylate or the above oligomers are particularly preferred.

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

Wherein (Y), n represents an integer of 1 to 10, R ^{1 'is} 2 divalent aliphatic or alicyclic hydrocarbon group or 5 to 20 carbon atoms, having 2 to 20 carbon atoms Represents a valent aromatic hydrocarbon group. Two R ² in each repeating unit ^', one is -NH-, the other is> N-C (= O) -R 3' is a group represented by the. R 3 ^'represents a hydroxyl group or a carbon - represents a group having a carbon unsaturated bond.
^'Of at least one R ^3' formula (Y) in R ³ is a carbon - is a group having a carbon unsaturated bond. ]

Among the reactive additives represented by the formula (Y), a compound represented by the following formula (YY) (hereinafter, may be referred to as a compound (YY)) is particularly preferable (note that n is the same as described above). Means).

As the compound (YY), a commercially available product can be used as it is or after purification as needed. Examples of commercially available products include Laromar (registered trademark) LR-9000 (manufactured by BASF).

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

(Protective layer laminating process)
In the protective layer laminating step, as shown in FIG. 3C, the covering region 35a for covering the polarizing layer 21 and the polarizing layer 21 are exposed on the polarizing layer 21 of the laminated film 62 prepared in the preparatory step. A protective layer 35 having an exposed region 35b for the purpose is laminated. As a result, the laminated film 63 with a protective layer can be obtained. The exposed area 35b can be, for example, an opening of the protective layer 35. In the covering region 35a, when the liquid material capable of reducing the content of the dichroic dye in the polarizing layer 21 described later and the laminated film 63 with the protective layer are brought into contact with each other, the liquid material comes into contact with the polarizing layer 21. Can be suppressed. On the other hand, in the exposed region 35b of the protective layer 35, the liquid material can be brought into contact with the polarizing layer 21.

As will be described later, when the polarizing layer 21 comes into contact with the liquid material, the liquid material permeates into the polarizing layer 21 and loses the function of the dichroic dye as a dye. Therefore, it is preferable that the exposed region 35b is formed corresponding to the region in the polarizing layer 21 where the content of the dichroic dye can be reduced. For example, when the polarizing film 1 shown in FIGS. 1 (a) and 1 (b) is manufactured, it is preferable to determine the shape according to the shape of the second region 11b. For example, if the plan view shape of the second region 11b is circular; elliptical; oval; polygonal such as triangle, square, rectangle, rhombus; linear; strip; wavy, etc., the exposed region 35b is these. It may be formed according to the shape of.

For example, when the exposed region 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 region 35b is elliptical or oval, its long axis 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 a polygon, the diameter of the virtual circle drawn so that the polygon is inscribed is preferably 5 cm or less, more preferably 3 cm or less, and preferably 2 cm or less. More preferred. As will be described later, since the liquid substance permeates into the liquid crystal layer, the size of the exposed region 35b may be formed to be slightly smaller than the size of the second region 11b.

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

As the protective layer 35, a sheet-like base material having an exposed region 35b formed therein can be used. The region to be the exposed region 35b is a method of mechanically punching a predetermined portion of the sheet-like base material by punching, a cutting plotter, a water jet or the like, and removing the predetermined portion of the sheet-like base material by laser ablation, chemical dissolution or the like. It can be formed by a method or the like.

The sheet-like base material forming the protective layer 35 is insoluble in the liquid material when brought into contact with a liquid material capable of reducing the content of the dichroic dye in the liquid crystal layer described later, and also removes the liquid material. The material is not particularly limited as long as it has durability in ultraviolet irradiation performed after contacting a liquid substance. As the sheet-like base material on which the protective layer 35 is formed, for example, it can be formed using the same material as the base material layer 13 described above, and it is particularly preferable to form the protective layer 35 using a resin base material. It is more preferable to use a polyester resin such as polyethylene terephthalate, which easily suppresses deformation of the region (for example, the opening) that becomes the exposed region 35b.

The protective layer 35 preferably has an adhesive layer for bonding to the polarizing layer 21. Since the protective layer 35 is peeled off as described later, it is preferable that the adhesive layer can be peeled off from the polarizing layer 21. The thickness of the protective layer 35 is usually 20 μm or more, preferably 30 μm or more, and usually 250 μm or less, preferably 200 μm or less.

(Decolorization process)
In the decolorization step, the laminated film 63 with the protective layer obtained in the protective layer laminating step is brought into contact with a liquid material capable of reducing the content of the dichroic dye in the polarizing layer 21, thereby causing a part of the polarizing layer 21. A decolorized laminated film 64 having a reduced content of the dichroic dye in the region can be obtained (FIG. 3 (d)). Since the protective layer 35 of the laminated film 63 with a protective layer has a coating region 35a for covering the polarizing layer 21 and an exposed region 35b for exposing the polarizing layer 21, a liquid substance is formed in the exposed region 35b. It can be brought into contact with the polarizing layer 21. As a result, the content of the dichroic dye can be reduced in the region of the polarizing layer 21 in contact with the liquid material.

The contact between the laminated film 63 with the protective layer and the liquid material can be performed by immersing the laminated film 63 with the protective layer in the liquid material, applying the liquid material to the laminated film 63 with the protective layer, spraying, dropping, or the like. , It is preferable to carry out by a method of immersing the laminated film 63 with a protective layer in a liquid material. As a result, of the polarizing layer 21, the liquid material comes into contact with the surface of the polarizing layer 21 exposed from the exposed region 35b of the protective layer 35 and permeates the inside of the polarizing layer 21. Although the details are not clear, the liquid material that has penetrated into the polarizing layer 21 can be used as a dichroic dye by decomposing the dichroic dye in the polarizing layer 21 or reacting with the dichroic dye. It is thought that the function of As a result, a second region 11b, which is a region having a lower content of the dichroic dye than the other regions, is formed in a part of the polarizing layer 21, and the decolorized laminated film 64 having the liquid crystal layer 11 (FIG. 3 (FIG. 3). d)) can be obtained.

Of the surface of the polarizing layer 21, the region covered with the covering region 35a of the protective layer 35 does not come into direct contact with the liquid material, so that the liquid material does not easily penetrate into the polarizing layer 21 and the dichroic dye is present. Hard to disappear. On the other hand, in the region of the polarizing layer 21 exposed from the exposed region 35b of the protective layer 35, the polarizing layer 21 comes into direct contact with the liquid material, so that the liquid material easily permeates into the polarizing layer 21 and is a dichroic dye. Is easily lost. Therefore, in the decolorized laminated film 64 shown in FIG. 3D, a second region of the polarizing layer 21 corresponding to the exposed region 35b is a low polarization region in which the content of the dichroic dye is smaller than that of the other regions. The liquid crystal layer 11 having the region 11b can be formed.

As described above, by using the laminated film 63 with a protective layer in which the exposed region 35b of the protective layer 35 is arranged in the region of the polarizing layer 21 where the content of the dichroic dye is desired to be reduced, the desired position of the polarizing layer 21 is obtained. The liquid crystal layer 11 in which the content of the dichroic dye is reduced can be formed. However, since the liquid material permeates the inside of the polarizing layer 21 and loses the function of the dichroic dye, the liquid material permeates into a region where it is not necessary to reduce the content of the dichroic dye and is dichroic. The thickness of the protective layer 35, the size of the exposed region 35b, the concentration of the liquid substance, the immersion time of the laminated film with the protective layer in the liquid substance, and the laminated film 63 with the protective layer so as not to reduce the content of the dye. It is preferable to adjust the amount of liquid material applied to, the amount of spray, the amount of dropping, and the like.

The liquid material capable of reducing the content of the bicolor dye in the polarizing layer 21 is not particularly limited as long as the content of the bicolor dye can be reduced, but for example, peroxides (hydrogen peroxide, sodium percarbonate, etc.) and the like. A chlorine compound (sodium hypochlorite or the like), an acid (sulfuric acid, nitric acid, hexafluorophosphate), an alkali (sodium hydroxide, potassium hydroxide) or the like can be appropriately used. Among them, acids such as sulfuric acid, nitric acid and hexafluorophosphoric acid are preferable. These liquids may be used alone or in combination.

The contact conditions for bringing the laminated film 63 with the protective layer into contact with the liquid material may be appropriately selected according to the thickness of the polarizing layer 21 and the range in which the content of the dichroic dye is reduced. The concentration of the liquid material is, for example, preferably 20 to 80% by mass, and more preferably 30 to 70% by mass. The temperature of the liquid material is preferably 50 to 150 ° C, more preferably 80 to 120 ° C.

In the decoloring step, the laminated film 63 with a protective layer is brought into contact with the liquid material to form a region in a part of the polarizing layer 21 having a lower content of the dichroic dye than the other regions, and then the liquid material is formed. It is preferable to provide a first washing step for washing away. The first cleaning step can be performed using an organic solvent such as water or alcohol.

(Peeling process)
In the peeling step, the protective layer 35 is peeled from the decolorized laminated film 64 obtained in the decolorizing step. As a result, the polarizing film 1 (FIGS. 1 (a) and 1 (b)) in which the second region 11b, which is a region in which the content of the dichroic dye is lower than that of the other regions, is formed in a part of the liquid crystal layer 11. Can be obtained.

The polarizing film 1 shown in FIG. 1B can also be used by peeling off the base material layer 13. In this case, the alignment layer 12 may be peeled off together with the base material layer 13. For example, the base material layer 13 can be peeled off after the liquid crystal layer 11 of the polarizing film 1 is attached to a member forming a display device, a retardation layer, or the like.

(Method of continuously manufacturing polarizing film)
The method for producing the polarizing film 1 can preferably be continuously produced by the Roll to Roll format. In this case, a laminated film wound in a roll shape may be prepared in the preparatory step, and the laminated film may be conveyed while being unwound, and the protective layer laminating step, the decoloring step, and the peeling step may be continuously performed. In the protective layer laminating step, the protective layer wound in a roll shape may be unwound and conveyed, and the protective layer may be bonded to the laminated film to obtain a laminated film with a protective layer. In the decolorization step, the laminated film with the protective layer is continuously conveyed and passed through a liquid bath filled with the liquid material, or the laminated film with the protective layer is continuously conveyed and the liquid material is applied, sprayed or or sprayed. It may be dropped to obtain a decolorized laminated film. In the peeling step, the protective layer may be continuously peeled from the decolorized laminated film, and the polarizing film may be wound into a roll to form a wound body. The polarizing film continuously produced as described above can have a length of, for example, 10 m or more.

When the preparatory step includes an orientation layer forming step, the base layer wound in a roll shape is unwound and conveyed, and the orientation layer forming composition is continuously coated on the base layer by a coating device. It may be processed to form an alignment layer. When the preparatory step includes a polarizing layer forming step, the polarizing layer forming composition is applied to the surface of the base layer with the alignment layer on the side where the alignment layer is formed while continuously transporting the base layer with the alignment layer. It may be applied to form a polarizing layer.

In the polarizing film 1 manufactured by 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 the polarizing film 1 having no step is formed. Can be obtained. As a result, even if another film is attached onto the polarizing layer 21 with an adhesive or the like, the other film can be laminated without biting air bubbles.

<Manufacturing method of polarizing film (second manufacturing method)>
In addition to the above-mentioned first manufacturing method, the polarizing film 1 can also be manufactured by the second manufacturing method shown below. FIG. 4 is a schematic cross-sectional view showing an example of a liquid material contacting step in the method for producing the polarizing film 1 shown in FIG. 1 (b). The second method for producing the polarizing film 1 is
A preparatory step of preparing a laminated film 62 (FIG. 3 (b)) having a polarizing layer 21 containing a liquid crystal compound and a dichroic dye on at least one side of the base material layer 13.
By contacting a part of the polarizing layer 21 of the laminated film 62 with a liquid material that can reduce the content of the dichroic dye in the polarizing layer 21, the content of the dichroic dye in the part of the film 62 The polarizing film 1 shown in FIGS. 1 (a) and 1 (b) can be produced by having a liquid material contacting step (FIG. 4) for reducing the temperature.

The preparatory step in the second manufacturing method is the same as the preparatory step in the first manufacturing method described with reference to FIGS. 3A and 3B. By this preparatory step, the laminated film 62 having the polarizing layer 21 is prepared.

In this second manufacturing method, a part of the polarizing layer 21 on the laminated film 62 is brought into contact with the liquid material (FIG. 4). The liquid material used at this time can reduce the content of the dichroic dye in a part of the polarizing layer 21, and is the same as the liquid material used in the decolorization step in the first production method described above. Liquid material can be used. As a method of bringing the liquid material into contact with a part of the polarizing layer 21, for example, as shown in FIG. 4, a so-called inkjet method in which the liquid material is dropped and applied to the part of the region can be mentioned. .. By bringing the polarizing layer 21 into contact with the liquid material, the liquid material permeates a part of the region of the polarizing layer 21, and the content of the dichroic dye can be reduced to form a low polarization region.

The second manufacturing method preferably includes a second cleaning step of bringing the polarizing layer 21 into contact with the liquid material and then washing away the liquid material on the polarizing layer 21. 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 production method. As a result, the polarizing film 1 shown in FIG. 1B can be obtained.

As for the second manufacturing method, similarly to the first manufacturing method, the polarizing film 1 can be continuously manufactured by, for example, the Roll to Roll format. In this case, a laminated film wound in a roll shape may be prepared in the preparatory step, and the laminated film may be conveyed while being unwound to continuously perform the liquid material contacting step. In the liquid material contacting step, the laminated film may be continuously conveyed, and the liquid material may be dropped and applied to obtain a polarizing film, and the obtained polarizing film may be wound into a roll to form a wound body. The polarizing film continuously produced as described above can have a length of, for example, 10 m or more.

When the preparatory step includes an orientation layer forming step, the base layer wound in a roll shape is unwound and conveyed, and the orientation layer forming composition is continuously coated on the base layer by a coating device. It may be processed to form an alignment layer. When the preparatory step includes a polarizing layer forming step, the polarizing layer forming composition is applied to the surface of the base layer with the alignment layer on the side where the alignment layer is formed while continuously transporting the base layer with the alignment layer. It may be applied to form a polarizing layer.

Also by 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 polarizing film 1 having no steps can be obtained. As a result, even if another film is attached onto the polarizing layer 21 with an adhesive or the like, the other film can be laminated without biting air bubbles.

<Manufacturing method of circularly polarizing plate>
The circular polarizing plate can be manufactured by laminating the polarizing film 1 and the retardation layer. As described above, when the polarizing film is a continuously manufactured long polarizing film having a length of 10 m or more, a long retardation layer having a length of 10 m or more is used as the retardation layer, and both are continuously produced. It is preferable to form a long laminated body by laminating a long polarizing film and a long retardation layer while carrying the film. 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 and laminate the two.

The method for manufacturing a circular polarizing plate is to attach a long laminate obtained by laminating a long polarizing film and a long retardation layer to a display device of a predetermined size or the like for attaching the polarizing film to a sheet of a predetermined size. It may have a step of cutting into. In the cutting step, it is preferable to cut the long laminated body in at least one of the length direction and the width direction of the long laminated body. In this case, it is preferable to determine the cutting position in the long laminated body so that the second region 11b of the liquid crystal layer 11 is arranged at a predetermined position in the cut sheet.

The present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples.

[Luminosity factor correction polarization (Py) and luminosity factor transmittance (Ty)]
(Preparation of evaluation sample)
The composition for forming an orientation layer and the composition for forming a polarizing layer used in each of Examples, Comparative Examples and Reference Examples were prepared. In addition, the same film used as the base material layer in each of Examples, Comparative Examples, and Reference Examples was cut out to a size of 40 mm × 40 mm and prepared as the base material layer of the evaluation sample. Using these, the protective layer was not used in Examples 1 and 2, Comparative Examples and Reference Examples, and in Example 3, the entire surface of the polarizing layer was brought into contact with the solution instead of partially dropping the solution onto the polarizing layer. Except for the above, the same procedure as for producing the polarizing films of each Example, Comparative Example and Reference Example was carried out to obtain an evaluation sample.

(Luminosity factor correction polarization (Py) and luminosity factor transmittance (Ty))
For the evaluation sample, the luminosity factor correction simple substance transmittance (Ty) and the luminosity factor correction polarization degree (Py) were calculated by the following procedure. Set the transmittance in the transmission axis direction (T ₁ ) and the transmittance in the absorption axis direction (T ₂ ) in the wavelength range of 380 nm to 780 nm in a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation). It was measured by the double beam method using the above-mentioned device. The folder was provided with a mesh that cuts the amount of light by 50% on the reference side. Using the following (Equation 1) and (Equation 2), the transmittance and polarization degree at each wavelength are calculated, and the luminosity factor is further corrected by the 2 degree field (C light source) of JIS Z 8701 to correct the luminosity factor. (Ty) and the luminosity factor correction polarization degree (Py) were calculated.
Polarization degree [%] = {(T _1- T ₂ ) / (T ₁ + T ₂ )} x 100 (Equation 1)
Elemental transmittance [%] = (T ₁ + T ₂ ) / 2 (Equation 2)

・溶剤：ｏ−キシレン ９８部[Example 1]
(Manufacturing of composition for forming alignment layer)
The following components were mixed, and the obtained mixture was stirred at 80 ° C. for 1 hour to obtain a composition for forming an alignment layer, which is a composition for forming a photoalignment film.
-Two parts of polymer with photoreactive groups shown below

・ Solvent: 98 parts of o-xylene

・式（１−７）で表される重合性液晶化合物 ２５部

・下記に示す二色性色素（１） ２．８部

・下記に示す二色性色素（２） ２．８部

・下記に示す二色性色素（３） ２．８部

・下記に示す重合開始剤 ６部
２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（イルガキュア３６９；チバスペシャルティケミカルズ社製）
・下記に示すレベリング剤 １．２部
ポリアクリレート化合物（ＢＹＫ−３６１Ｎ；ＢＹＫ−Ｃｈｅｍｉｅ社製）
・下記に示す溶剤 ２５０部
シクロペンタノン(Manufacturing of composition for forming a polarizing layer)
The following components were mixed and stirred at 80 ° C. for 1 hour to obtain a composition for forming a polarizing layer. As the dichroic dye, the azo dye described in Examples of JP2013-101328A was used.
-75 parts of the polymerizable liquid crystal compound represented by the formula (1-6)

25 parts of polymerizable liquid crystal compound represented by the formula (1-7)

・ Dichroic dye shown below (1) 2.8 parts

・ The following dichroic dye (2) 2.8 parts

・ The following dichroic dye (3) 2.8 parts

-The following polymerization initiator 6 parts 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butane-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals)
-Leveling agent 1.2 parts shown below Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
・ 250 parts of solvent shown below Cyclopentanone

(Manufacturing of polarizing film)
A triacetyl cellulose film (KC4UY-TAC manufactured by Konica Minolta Co., Ltd., thickness 40 μm) as a base material layer was cut out to a size of 20 × 20 mm, and the surface thereof was subjected to corona treatment (AGF-B10, manufactured by Kasuga Electric Works Ltd.). The composition for forming an alignment layer was applied to the surface of the corona-treated film using a bar coater, and then 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 Ushio, Inc.) is used to irradiate the coating layer for the alignment layer with polarized UV at an integrated light intensity of 50 mJ / cm ² (313 nm standard) to form the alignment layer. Formed. The composition for forming a polarizing layer was applied onto the obtained alignment layer using a bar coater, and then dried in a drying oven set at 110 ° C. for 1 minute. After that, using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Denki Co., Ltd.), the liquid crystal was irradiated with ultraviolet rays (in a nitrogen atmosphere, wavelength: 365 nm, integrated light intensity at wavelength 365 nm: 1000 mJ / cm ² ). A polarizing layer in which the compound and the dichroic dye were oriented was obtained. A protective layer (AY-638 manufactured by Fujimori Kogyo Co., Ltd.) in which holes are punched on the polarizing layer to form openings. An adhesive layer having a thickness of 15 μm is provided on a polyester film having a thickness of 38 μm. After the bonding, the diphenyl4-thiophenoxyphenylsulfonium hexafluorophosphate (CPI-100P, manufactured by San-Apro Co., Ltd.) was immersed in a 50 wt% solution of propylene carbonate at 120 ° C. for 60 seconds. Then, the protective layer was peeled off to obtain a polarizing film.

When the appearance of the obtained polarizing film was visually observed, a circular region (low polarization region) in which the polarizing layer did not exist could be clearly confirmed, and a polarizing film having a polarizing region and a low polarization region was obtained. all right. Further, an evaluation sample was prepared by the above procedure, and the luminosity factor correction transmittance (Ty) and the luminosity factor correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Example 2]
Instead of using a triacetyl cellulose film as the base material layer, the surface of a 1/4 wave plate (Zeonoa film, Nippon Zeon Co., Ltd., in-plane retardation value Ro: 138 nm), which is a uniaxially stretched film of a cyclic olefin resin. A polarizing film was obtained in the same manner as in Example 1 except that the slow-phase axis and the absorption axis of the polarizing layer were laminated at 45 ° using a hard-coated film. Further, an evaluation sample was prepared by the above procedure, and the luminosity factor correction transmittance (Ty) and the luminosity factor correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Example 3]
Instead of sticking a protective layer that has been punched with a hole punch to form an opening, a dropper is used to partially top the polarizing layer with diphenyl4-thiophenoxyphenylsulfonium hexafluorophosphate (San Apro stock). A polarizing film was obtained in the same manner as in Example 1 except that a 50 wt% solution of propylene carbonate (CPI-100P) manufactured by the company was added dropwise. Further, an evaluation sample was prepared by the above procedure, and the luminosity factor correction transmittance (Ty) and the luminosity factor correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Comparative example]
Same as in Example 1 except that methanol was used at room temperature instead of a 50 wt% solution of propylene carbonate of diphenyl4-thiophenoxyphenylsulfonium hexafluorophosphate (CPI-100P, manufactured by San Apro Co., Ltd.). A polarizing film was obtained. When the appearance of the obtained polarizing film was visually observed, it was found that a region in which the polarizing layer did not exist could not be confirmed, and a polarizing film having a polarizing region and a low polarizing region was not obtained. Further, an evaluation sample was prepared by the above procedure, and the luminosity factor correction transmittance (Ty) and the luminosity factor correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Reference example]
A polarizing film was obtained in the same manner as in Example 1 except that a 50 wt% solution of propylene carbonate of diphenyl4-thiophenoxyphenylsulfonium hexafluorophosphate (CPI-100P, manufactured by San Apro Co., Ltd.) was not used. When the appearance of the obtained polarizing film was visually observed, it was not possible to confirm the region where the polarizing layer did not exist, and it was found that the polarizing film having a polarizing region and a low polarizing region was not obtained. Further, an evaluation sample was prepared by the above procedure, and the luminosity factor correction transmittance (Ty) and the luminosity factor correction polarization degree (Py) were calculated. The results are shown in Table 1.

The values of the luminosity-corrected transmittance (Ty) and the luminosity-corrected polarization degree (Py) measured in each of the Examples, Comparative Examples, and Reference Examples shown in Table 1 are the luminosity-corrected transmittance (Py) of the base material layer. It is a value including the values of Ty) and the luminosity correction polarization degree (Py), but the luminosity correction transmittance (Ty) of the base material layer alone is 92%, and the luminosity correction polarization degree (Py) of the base material layer is used. Since the value of Py) is 0%, the value of the luminosity function-corrected transmittance (Ty) is the value shown in Table 1 when the base material layer is excluded 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 polarization degree (Py) becomes the same as the value shown in Table 1.

1 Polarizing film, 5a to 5c circular polarizing plate, 11 liquid crystal layer, 11a first region, 11b second region, 12 alignment layer, 13 base material layer, 15 retardation layer, 21 polarizing layer, 35 protective layer, 35a coating region , 35b Exposed area, 61 Base material layer with alignment layer, 62 Laminated film, 63 Laminated film with protective layer, 64 Decolorized laminated film.

Claims (20)

A polarizing film having a liquid crystal layer.
The liquid crystal layer contains a liquid crystal compound and has at least two regions distinguished by a value of luminosity factor correction polarization.
The at least two regions are polarizing films in which the contents of the dichroic dyes are different from each other. In addition, the substrate layer and
It has an orientation layer laminated on at least one side of the base material layer, and has.
The polarizing film according to claim 1, wherein the liquid crystal layer is laminated on the alignment layer. The polarizing film according to claim 2, wherein the alignment layer contains a photoalignable 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 liquid crystal layer has a first region containing a dichroic dye and a second region in which the content of the dichroic dye is lower than that of the first region.
The luminosity factor correction polarization degree in the first region is 90% or more.
The polarizing film according to any one of claims 1 to 4, wherein the luminosity factor correction polarization degree in the second region is 10% or less. The liquid crystal layer has a first region containing a dichroic dye and a second region in which the content of the dichroic dye is lower than that of the first region.
The luminosity factor correction single transmittance in the first region is 35% or more.
The polarizing film according to any one of claims 1 to 5, wherein the visible sensitivity correction simple substance transmittance of the second region is 80% or more. The second region has a circular, elliptical, oval or polygonal shape in a plan view.
When the second region is circular, the diameter is 5 cm or less.
When the second region is elliptical or oval, the major axis is 5 cm or less.
The polarizing film according to claim 5 or 6, wherein when the second region is a polygon, the diameter of the virtual circle drawn so that the polygon is inscribed is 5 cm or less. The polarizing film according to any one of claims 5 to 7, wherein the first region shows a Bragg peak in X-ray diffraction measurement. In addition, it has a substrate layer and
The polarizing film according to any one of claims 1 to 8, wherein the base material layer has a 1/4 wave 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 formed by laminating the polarizing film according to any one of claims 1 to 8 and 10 and a retardation layer having a 1/4 wave plate function. A preparatory step of preparing 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
By contacting a part of the polarizing layer of the laminated film with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer, the dichroic dye is brought into contact with a part of the polarizing layer. A method for producing a polarizing film, comprising a liquid material contacting step of reducing the content of the polarizing film. The liquid material contacting step is
A protective layer is formed by laminating a protective layer having a coating region for coating the polarizing layer and an exposed region for exposing the polarizing layer on the polarizing layer of the laminated film prepared in the preparation step. Protective layer lamination process to obtain laminated film with
By contacting the laminated film with the protective layer with a liquid material capable of reducing the content of the dichroic dye in the polarizing layer, the content of the dichroic dye is reduced in a part of the polarizing layer. Decolorization process to obtain a decolorized laminated film and
The method for producing a polarizing film according to claim 12, further comprising a peeling step of peeling the protective layer from the decolorized laminated film. The exposed area in the protective layer has a circular, elliptical, oval or polygonal shape in a plan view.
When the exposed area is circular, the diameter is 5 cm or less.
When the exposed area is elliptical or oval, the major axis is 5 cm or less.
The method for producing a polarizing film according to claim 13, wherein when the exposed region is a polygon, the diameter of the virtual circle drawn so that the polygon is inscribed is 5 cm or less. The preparation step is
An alignment layer forming step of applying a composition for forming an alignment layer on one side of the base material layer to form an alignment layer,
A polarizing layer forming step of applying a polarizing layer forming composition containing the liquid crystal compound and the dichroic dye to the surface of the base material layer on the side where the alignment layer is formed to form the polarizing layer. The method for producing a polarizing film according to any one of claims 12 to 14, which has the above. The composition for forming an alignment layer contains a photoalignable polymer and contains.
The polarizing film according to claim 15, wherein in the alignment layer forming step, the alignment layer coating layer formed by coating the alignment layer forming composition is irradiated with polarized light to form the alignment layer. Production method. The liquid crystal compound is a polymerizable liquid crystal compound.
The polarizing layer forming step according to claim 15 or 16, wherein the polarizing layer coating layer formed by coating the polarizing layer forming composition is irradiated with active energy rays to form the polarizing layer. How to manufacture a polarizing film. The method for producing a polarizing film according to any one of claims 12 to 17, wherein the polarizing film has a length of 10 m or more. A circle comprising a retardation layer laminating step of laminating a polarizing film produced by the method for producing a polarizing film according to any one of claims 12 to 18 and a retardation layer having a 1/4 wave plate function. Method for manufacturing a polarizing plate. The polarizing film is a long polarizing film having a length of 10 m or more.
The retardation layer is a long retardation layer having a length of 10 m or more.
In the retardation layer laminating step, a long laminate is formed by laminating the long polarizing film and the long retardation layer.
The method for manufacturing a circular polarizing plate according to claim 19, further comprising a cutting step of cutting the long laminate into single sheets.

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