KR20240101728A - Polarizing film and method for manufacturing same - Google Patents

Abstract

The polarizing film has a liquid crystal layer. The liquid crystal layer contains a liquid crystal compound and has at least two regions distinguished by the value of the visibility correction polarization degree. At least two regions have different content rates of the dichroic dye.

Description

Polarizing film and method of manufacturing the same {POLARIZING FILM AND METHOD FOR MANUFACTURING SAME}

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

Organic EL displays using organic light-emitting diodes (OLEDs) are not only lighter and thinner than liquid crystal displays, but can also achieve high image quality such as wide viewing angles, fast response speeds, and high contrast, making them suitable for use in smartphones and televisions. , digital cameras, etc., are used in various fields. In an organic EL display device, it is known to improve anti-reflection performance by using a circular polarizer or the like in order to suppress a decrease in visibility due to reflection of external light.

As a polarizing film used in such a circular polarizer, Japanese Patent Application Laid-Open No. 2015-206852 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2015-212823 (Patent Document 2) laminate a patterned liquid crystal cured film on a substrate. One pattern polarizing film is described.

Japanese Patent Publication No. 2015-206852 Japanese Patent Publication No. 2015-212823

The purpose of the present invention is to provide a novel polarizing film having at least two regions with different visibility correction polarization values and a method of manufacturing the same.

The present invention provides the polarizing film shown below and its manufacturing method.

[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 the value of the visibility correction polarization degree,

A polarizing film in which the at least two regions have different dichroic dye contents.

[2] Additionally, a base layer,

It has an orientation layer laminated on at least one side of the base layer,

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 orientation layer contains a photo-alignment polymer.

[4] The polarizing film according to any one of [1] to [3], wherein the liquid crystal compound includes a polymerizable liquid crystal compound.

[5] The liquid crystal layer has a first region containing a dichroic dye and a second region where the content of the dichroic dye is lower than that of the first region,

The visibility correction polarization degree of the first area is 90% or more,

The polarizing film according to any one of [1] to [4], wherein the visibility correction polarization degree of the second region is 10% or less.

[6] The liquid crystal layer has a first region containing a dichroic dye and a second region where the content of the dichroic dye is lower than that of the first region,

The visibility corrected single transmittance of the first area is 35% or more,

The polarizing film according to any one of [1] to [5], wherein the visibility corrected single transmittance of the second region is 80% or more.

[7] The second region has a circular, oval, oval or polygonal shape when viewed in plan,

When the second region is circular, the diameter is 5 cm or less,

When the second region is oval or oval, the major axis is 5 cm or less,

The polarizing film according to any one of [5] or [6], wherein when the second region is a polygon, the diameter of a 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 exhibits a Bragg peak in X-ray diffraction measurement.

[9] Additionally, it has a base layer,

The polarizing film according to any one of [1] to [8], wherein the base layer has a quarter wave plate function.

[10] The polarizing film according to any one of [1] to [9], wherein the polarizing film has a length of 10 m or more.

[11] A circularly polarizing plate formed by laminating the polarizing film according to any one of [1] to [8] and [10] and a retardation layer having a quarter wave plate function.

[12] A preparation 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 layer,

Reducing the content of a dichroic dye in a partial region of the polarizing layer by contacting a portion 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. A method for producing a polarizing film having a liquid contact process.

[13] The liquid contact process is,

A protective layer-forming laminated film is obtained by laminating a protective layer having a covering area for covering the polarizing layer and an exposed area for exposing the polarizing layer on the polarizing layer of the laminated film prepared in the above preparation step. Layer stacking process,

A decolorized laminated film in which the content of a dichroic dye in a partial region of the polarizing layer is reduced by bringing the protective layer-forming laminated film into contact with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer. The decolorization process obtained,

The method for producing a polarizing film according to [12], comprising a peeling step of peeling the protective layer from the decolorizing laminated film.

[14] The exposed area in the protective layer has a circular, oval, oval or polygonal shape when viewed in plan,

When the exposed area is circular, the diameter is 5 cm or less,

When the exposed area is oval or oval, the major diameter is 5 cm or less,

When the exposed area is a polygon, the diameter of a virtual circle drawn so that the polygon is inscribed is 5 cm or less.

[15] The preparation process is,

An orientation layer forming step of forming an orientation layer by coating a composition for forming an orientation layer on one side of the base layer;

[12] - having a polarizing layer forming step of forming the polarizing layer by coating a composition for forming a polarizing layer containing the liquid crystal compound and the dichroic dye on the surface of the base layer on the side where the alignment layer is formed. The method for producing a polarizing film according to any one of [14].

[16] The composition for forming the alignment layer includes a photo-alignment polymer,

The method for producing a polarizing film according to [15], wherein the orientation layer forming step forms the orientation layer by applying polarized light to a coating layer for an orientation layer formed by coating the composition for forming an orientation layer.

[17] The liquid crystal compound is a polymerizable liquid crystal compound,

The polarizing layer forming step is a method for producing a polarizing film according to [15] or [16], wherein the polarizing layer is formed by applying active energy rays to the polarizing layer coating layer formed by coating the composition for forming the polarizing layer. .

[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 circularly polarizing plate having a polarizing film manufactured by the polarizing film manufacturing method according to any one of [12] to [18] and a retardation layer stacking process for laminating a retardation layer having a quarter wave plate function. Manufacturing method.

[20] The polarizing film is a long polarizing film with a length of 10 m or more,

The retardation layer is a long retardation layer with a length of 10 m or more,

The retardation layer stacking process forms a long laminate by laminating the long polarizing film and the long retardation layer,

Additionally, the method for producing a circularly polarizing plate according to [19], which includes a cutting step of cutting the elongated laminate into sheets.

According to the present invention, a polarizing film having at least two regions with different visibility correction polarization values and a method for manufacturing the same can be provided.

Fig. 1(a) is a schematic plan view showing an example of the polarizing film of the present invention, and (b) is a cross-sectional view taken along line XX in (a).
2(a) to 2(c) are schematic cross-sectional views each showing an example of the circular polarizing plate of the present invention.
3(a) to 3(d) are schematic cross-sectional views showing an example of the layer structure obtained in each step of the manufacturing process of the polarizing film of the present invention.
FIG. 4 is a schematic cross-sectional view showing an example of a liquid substance contact step in the method for producing a polarizing film of the present invention.

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

＜Polarizing film＞

FIG. 1(a) is a schematic plan view showing an example of the polarizing film of the present invention, and FIG. 1(b) is a cross-sectional view taken along the line X-X of FIG. 1(a). The polarizing film 1 of this embodiment is a film having the 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 visibility-corrected polarization degree (Py), and these at least two regions have different content rates of the dichroic dye. The polarizing film 1 has a liquid crystal layer 11, but may further have a base material layer 13, an orientation layer 12, other layers, etc. In the polarizing film 1 shown in FIG. 1(b), an example is shown having an alignment layer 12 and a liquid crystal layer 11 on one side of the base material layer 13, but the alignment layer is on both sides of the base layer 13. It may have a layer and a liquid crystal layer. The structures of the liquid crystal layers formed on both surfaces of the base layer 13 may be the same or different from each other.

The polarizing film 1 may be a long polarizing film with a length of 10 m or more, and in this case, the polarizing film 1 can be a wound body wound into a roll shape. A polarizing film can be continuously unwound from this wound body, laminated with a retardation layer described later, and cut into sheets, etc. can be performed. The length of the long polarizing film used as a wound product is not particularly limited as long as it is 10 m or more, but can be, for example, 10,000 m or less.

(Liquid crystal layer)

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

In the liquid crystal layer 11, the region containing the dichroic dye and the liquid crystal compound, and in which the dichroic dye and the liquid crystal compound are aligned horizontally with respect to the plane of the polarizing film 1, is the liquid crystal orientation with respect to light with a wavelength λ nm. It is preferable that the dichroic ratio (= A1 (λ)/A2 (λ)), which is the ratio of the absorbance A1 (λ) in the horizontal direction and the absorbance A2 (λ) in the vertical direction within the liquid crystal orientation plane, is 7 or more, and more preferably 20 or more. , more preferably 30 or more. The higher this value, the higher the absorption selectivity and polarization characteristics. Although it may vary depending on the type of dichroic dye, when the liquid crystal layer 11 is a nematic liquid crystalline phase, the above ratio is about 5 to 10. In addition, when the liquid crystal layer 11 is a nematic liquid crystal phase or a smectic liquid crystal phase described later, the liquid crystal compound and the dichroic dye are not phase separated, for example, through surface observation using various microscopes or scattering using a haze meter. It can also be confirmed by measurement.

As shown in FIGS. 1(a) and 1(b), the liquid crystal layer 11 has a first region 11a distinguished by the visibility-corrected polarization degree (Py) and further distinguished by the content of the dichroic dye. and a second region 11b. In the polarizing film 1 shown in FIG. 1(a), an example is shown having two regions each having different visibility correction polarization degree (Py) and dichroic dye content, but the first region and the second region are There may be two or more of each, and you may have three or more regions in which the content of the dichroic dye is different from each other.

The first region 11a of the polarizing film 1 shown in Fig. 1(a) contains a liquid crystal compound and a dichroic dye. The second region 11b contains a liquid crystal compound, but may or may not contain a dichroic dye. When it contains a dichroic dye, its content ratio is the dichroism contained in the first region 11a. It is preferable that it is less than the pigment content.

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

The first region 11a is preferably a region with high polarization characteristics, for example, the visibility corrected polarization (Py) can be 90% or more, preferably 92% or more, and more preferably 95% or more. and is usually 100% or less. In addition, the visibility correction single transmittance (Ty) of the first region 11a can be, for example, 35% or more, preferably 40% or more, more preferably 44% or more, and usually less than 50%. .

The second area 11b is preferably a low-polarization area with a visibility-corrected polarization degree (Py) lower than the visibility-correction polarization degree (Py) of the first area 11a. The visibility 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 may be 0%. Moreover, it is preferable that the second area 11b has a visibility correction single transmittance Ty higher than the visibility correction single transmittance Ty of the first area 11a. The second region 11b can have a visibility-corrected single transmittance (Ty) of, for example, 80% or more, preferably 85% or more, more preferably 88% or more, and usually 98% or less.

The visibility corrected polarization degree (Py) and the visibility corrected single transmittance (Ty) in this specification can be calculated based on the polarization degree and single transmittance measured using a spectrophotometer. For example, in the range of visible light wavelength 380 nm to 780 nm, the transmittance (T ₁ ) in the transmission axis direction (direction perpendicular to the orientation) and the transmittance (T ₂ ) in the absorption axis direction (same direction as the orientation) are measured using a polarizer in a spectrophotometer. Measurement can be made using the double beam method using a device with a forming folder set. The polarization degree and single transmittance in the visible light range are calculated using the following equations (Equation 1) and (Equation 2) to calculate the polarization degree and single transmittance at each wavelength, and also calculate the polarization degree and single transmittance at each wavelength in JIS Z 8701 (C light source) ) By performing visibility correction, the visibility correction single transmittance (Ty) and visibility correction polarization degree (Py) can be calculated.

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

Single 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 99% or more. It is more desirable. Moreover, the occupied area of the first area 11a is preferably 50% or more, and more preferably 70% or more, with respect to the total area of the occupied area of the first area 11a and the occupied area of the second area 11b. It is preferable, and it is more preferable that it is 80% or more. For example, as shown in FIG. 1(a), the occupied area of the second area 11b is smaller than the occupied area of the first area 11a, and the first area 11a is formed to surround the second area 11b. ) may be formed. In the polarizing film 1 shown in Fig. 1(a), the first region 11a is formed to surround one circular second region 11b, but the second regions 11b are each independently formed in plurality. It can be done.

The shape of the first area 11a and the shape of the second area 11b are not particularly limited, but for example, as shown in FIG. 1(a), the first area (11b) is formed to surround the second area 11b. When forming 11a), the second region 11b has a circular shape when viewed from the top; oval; Wonhyeong Jang; Polygons such as triangles, squares, squares, and diamonds; character shape; It can be formed into any shape, such as a combination of these.

The second region 11b preferably has a circular, oval, oval, or polygonal shape in plan view. When the second area 11b is circular, its diameter is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the second region 11b is oval or oblong, its major axis is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the second area 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 even more preferably 2 cm or less. The second area 11b of the above-mentioned shape can be suitably used as an area corresponding to the lens position of a camera provided in a smart phone, tablet, etc. Also, at this time, coloring of the second area 11b is achieved by making the second area 11b an area where the visibility corrected polarization degree (Py) is 10% or less and the visibility corrected single transmittance (Ty) is 80% or more. Since the camera's performance can be improved by reducing the amount of noise and achieving excellent transparency.

Additionally, the first region 11a and the second region 11b may each be formed to have a shape such as a line shape, a strip shape, or a wave shape when viewed from the top. In this case, a plurality of first regions 11a and second regions 11b may be formed 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 1 μm to 100 μm. It is more preferable to be

In addition, when the polarizing film is a long polarizing film, the long polarizing film is usually cut to a predetermined size according to the use of the polarizing film, etc., so the first area 11a or the first region 11a is placed at a predetermined position of the polarizing film 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 two regions 11b are formed. For example, when the polarizing film after cutting is the polarizing film 1 shown in FIG. 1(a), a plurality of second regions 11b are formed at predetermined intervals in the longitudinal direction and/or the width direction of the elongated polarizing film. ) is desirable to form.

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. In addition, the thickness of the second region 11b in the liquid crystal layer 11 is preferably the same as the first region 11a, preferably 0.5 μm or more, more preferably 1 μm or more, and , it is preferable that it is 5 μm or less, and it is more preferable that it is 3 μm or less. The thickness of the liquid crystal layer 11 can be measured using an interference thickness meter, a laser microscope, or a stylus thickness meter.

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 is preferably 1 μm. It is more preferable that it is 0.5 ㎛ or less, and even more preferably it is 0.5 ㎛ or less. By making the thickness of the first region (11a) and the second region (11b) of the liquid crystal layer (11) the same and the step between the first region (11a) and the second region (11b) being small, the liquid crystal layer (11) When the retardation layer described later or other layers (such as a surface protective layer) are laminated, problems such as mixing of air bubbles and generation of wrinkles can be suppressed. In addition, when the polarizing film 1 having the liquid crystal layer 11 is wound into a roll, problems such as formation of winding marks 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 liquid crystal compound is not particularly limited, and rod-shaped liquid crystal compounds, disc-shaped liquid crystal compounds, and mixtures thereof can be used. Additionally, 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 a polymerizable liquid crystal compound, the color of the polarizing film can be arbitrarily controlled and the polarizing film can be significantly reduced in thickness. Additionally, since the polarizing film can be manufactured without performing stretching treatment, it can be used as a non-stretchable polarizing film without stretching relaxation due to heat.

A polymerizable liquid crystal compound refers to a compound that has a polymerizable group and also has liquid crystallinity. A polymerizable group means a group involved in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in the polymerization reaction by active radicals or acids generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxylanyl group, oxetanyl group, etc. . Among them, an acryloyloxy group, methacryloyloxy group, vinyloxy group, oxylanyl group, or oxetanyl group is preferable, and an acryloyloxy group is more preferable. The liquid crystal may be a thermotropic liquid crystal or a lyotropic liquid crystal, but when mixing with a dichroic dye as in the liquid crystal layer of this 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 exhibiting a nematic liquid crystal phase, or may be a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. When the liquid crystal layer 11 is a polymer film obtained through a polymerization reaction and exhibits a polarization function, the liquid crystal state shown by the polymerizable liquid crystal compound is preferably a smectic phase, and is more preferably a high-order smectic phase from the viewpoint of improving performance. . Among them, Smetic B phase, Smetic D phase, Smetic E phase, Smetic F phase, Smetic G phase, Smetic H phase, Smetic I phase, Smetic J phase, Smetic K phase or Smetic phase. A higher order smectic liquid crystal compound that forms an L phase is more preferred, and a higher order smectic liquid crystal compound that forms a smectic B phase, smectic F phase or smectic I phase is more preferred. If the liquid crystal layer 11 formed by the polymerizable liquid crystal compound is one of these high-order smectic phases, a region with higher polarization performance can be formed in the liquid crystal layer 11. Additionally, in this region of high polarization performance, a Bragg peak derived from a higher-order structure such as a hexatic phase or crystal phase is obtained in X-ray diffraction measurement. The Bragg peak is a peak derived from the periodic structure of molecular orientation, and a film with a periodic interval of 3 to 6 Å can be obtained. In the polarizing film 1 of the present embodiment, the liquid crystal layer 11 contains a polymer in which the polymerizable liquid crystal compound is polymerized in a smectic phase state, thereby providing, for example, a higher polarization characteristic to the first region 11a. It is desirable because it can be done.

Whether the polymerizable liquid crystal compound exhibits a nematic liquid crystalline phase or a smectic liquid crystalline phase can be confirmed, for example, as follows. After the composition for forming a polarizing film is applied to a substrate to form a coating film, the solvent contained in the coating film is removed by heat treatment under conditions in which the polymerizable liquid crystal compound does not polymerize. Subsequently, the coating film formed on the substrate is heated to the isotropic temperature and gradually cooled, and the resulting liquid crystal phase is inspected by texture observation using a polarizing microscope, X-ray diffraction measurement, or differential scanning calorimetry.

Such a polymerizable liquid crystal compound specifically 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 formula (A), X ¹ , X ² and X ³ each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein the The hydrogen atom may be substituted with a halogen atom, an alkyl group with 1 to 4 carbon atoms, a fluoroalkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 4 carbon atoms, a cyano group, or a nitro group, and may be substituted with a divalent aromatic group or a divalent alicyclic group. The carbon atom constituting the formula 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

Y ¹ , Y ² , W ¹ and W ² are each independently a single bond or a divalent linking group.

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

U ¹ and U ² each independently represent a polymerizable group or a hydrogen atom, and at least one is a polymerizable group.]

and compounds represented by (hereinafter sometimes referred to as compound (A)).

In compound (A), at least ^one of X ¹ , X ² and . In particular, it is preferable that X ^{1 and} It is more preferable to be When it contains the structure of a trans-cyclohexane-1,4-diyl group, there is a tendency for smectic liquid crystallinity to develop. In addition, the substituents optionally possessed by the 1,4-phenylene group, which may have a substituent, and the cyclohexane-1,4-diyl group, which may have a substituent, include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, or a butyl group; Halogen atoms such as a cyano group, a chlorine atom, or a fluorine atom can be mentioned. Preferably, it is unsubstituted.

Y ¹ and Y ² are, independently of each other, a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCO-, -N=N-, -CR ^a =CR ^b -, - C≡C- or CR ^a =N- is preferable, and R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y ¹ and Y ² are more preferably -CH ₂ CH ₂ -, -COO-, -OCO- or a single bond, and X ¹ , X ² and X ³ all contain a cyclohexane-1,4-diyl group. 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 occur.

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

Alkanediyl groups having 1 to 20 carbon atoms represented by V ¹ and V ² include methylene group, ethylene group, propane-1,3-diyl group, butane-1,3-diyl group, and 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, decane-1,10-diyl group, tetradecane-1 , 14-diyl group or icosane-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, crystallinity is improved and smectic liquid crystallinity tends to be easily developed.

Substituents optionally included in the alkanediyl group having 1 to 20 carbon atoms, which may have a substituent, include cyano groups and halogen atoms such as chlorine atoms and fluorine atoms, but the alkanediyl group is preferably unsubstituted, It is more preferable that it is an unsubstituted, linear alkanediyl group.

It is preferable that U ¹ and U ² are both polymerizable groups, and it is more preferable that both are photopolymerizable groups. Since a polymerizable liquid crystal compound having a photopolymerizable group can be polymerized under lower temperature conditions than a thermally polymerizable group, it is advantageous in that a polymer of the polymerizable liquid crystal compound can be formed with a high degree of order.

The polymerizable groups represented by U ¹ and U ² may be different from each other, but are preferably the same. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxylanyl group, oxetanyl group, etc. . Among them, an acryloyloxy group, methacryloyloxy group, vinyloxy group, oxylanyl group, or 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.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

Among the compounds exemplified above, Formula (1-2), Formula (1-3), Formula (1-4), Formula (1-6), Formula (1-7), Formula (1-8), Formula ( At least one type selected from the group consisting of 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. Moreover, when combining two or more types of polymerizable liquid crystal compounds, it is preferable that at least one type is compound (A), and it is more preferable that two or more types are compound (A). By combining two or more types of polymerizable liquid crystal compounds, liquid crystallinity may be temporarily maintained even at a temperature below the liquid crystal-crystal phase transition temperature. The mixing ratio when combining two types of polymerizable liquid crystal compounds is usually 1:99 to 50:50, preferably 5:95 to 50:50, and more preferably 10:90 to 50:50. do.

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

The content of the polymerizable liquid crystal compound in the liquid crystal layer 11 is usually 50 to 99.5 parts by mass, preferably 60 to 99 parts by mass, and more preferably 60 to 99 parts by mass, based on 100 parts by mass of the solid content of the liquid crystal layer 11. It is preferably 70 to 98 parts by mass, and 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 increase. Here, solid content refers to the total amount of components obtained by removing the solvent from the composition for forming a polarizing layer described later.

(dichroic pigment)

A dichroic dye refers to a dye that has properties where the absorbance in the major axis direction of the molecule and the absorbance in the minor axis direction are different. A dichroic dye is a dye that aligns with a liquid crystal compound and exhibits dichroism, and the dichroic dye itself may have polymerizability or may have liquid crystallinity. As a dichroic dye, it is preferable to have the characteristic of absorbing visible light, and it is more preferable to have a maximum absorption wavelength (λ _MAX ) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dye, oxazine dye, cyanine dye, naphthalene dye, azo dye, and anthraquinone dye. Among them, azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye, or a stilbenazo dye, and bisazo dye or trisazo dye is preferable. Dichroic dyes may be used individually or in combination of two or more types, but in order to obtain absorption in the entire visible light range, it is preferable to combine three or more types of dichroic dyes, and to combine three or more types of azo dyes. It is more desirable.

Azo dyes include, for example, formula (I)

T ¹ -A ¹ (-N=NA ² ) _p -N=NA ³ -T ² (I)

[In formula (I), A ¹ , A ² and A ³ are each independently a 1,4-phenylene group, a naphthalene-1,4-diyl group, which may have a substituent, or 2 which may have a substituent. It represents a divalent heterocyclic group, and T ¹ and T ² are independently an electron-withdrawing group or an electron-emitting group, and are positioned at substantially 180° with respect to the azo bonding plane. 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. In the range showing absorption in the visible region, the -N=N- bond may be substituted with a -C=C-, -COO-, -NHCO-, or -N=CH- bond.]

A compound represented by (hereinafter sometimes referred to as “compound (I)”) can be mentioned.

The substituents that the 1,4-phenylene group, naphthalene-1,4-diyl group and divalent heterocyclic group in A ¹ , A ² and A ³ optionally have include 1 to 4 carbon atoms such as methyl group, ethyl group or butyl group. alkyl group of ; Alkoxy groups having 1 to 4 carbon atoms, such as methoxy group, ethoxy group, or butoxy group; fluorinated alkyl groups having 1 to 4 carbon atoms, such as trifluoromethyl group; Cyano group; nitro group; Halogen atoms such as chlorine atoms and fluorine atoms; Substituted or unsubstituted amino groups such as amino groups, diethylamino groups, and pyrrolidino groups (a substituted amino group is an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or two substituted alkyl groups bonded together to form an alkyl group having 2 to 8 carbon atoms) The unsubstituted amino group that forms the alkanediyl group is -NH ₂ ). Additionally, examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, and hexyl group. Alkanediyl groups having 2 to 8 carbon atoms include ethylene group, propane-1,3-diyl group, butane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, Hexane-1,6-diyl group, heptane-1,7-diyl group, or octane-1,8-diyl group. In order to encapsulate Compound (I) in a high-order liquid crystal structure such as a smectic liquid crystal, A ¹ , A ² and A ³ are each independently 1,4-phenyl, unsubstituted, hydrogen substituted with a methyl group or methoxy group. A lene 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 of A ¹ , A ² and A ³ are 1,4-phenylene groups, which is more preferable in terms of both simplicity of molecular synthesis and high performance. .

Examples of the divalent heterocyclic group include groups obtained by removing two hydrogen atoms from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzoimidazole, oxazole, and benzoxazole. When A ² is a divalent heterocyclic group, a structure in which the molecular bond angle is substantially 180° is preferable, and specifically, benzothiazole, benzoimidazole, and benzoxazole structures in which two 5-membered rings are condensed. is more preferable.

T ¹ and T ² are independently an electron withdrawing group or an electron emitting group, and preferably have different structures, where T ¹ is an electron withdrawing group and T ² is an electron emitting group, or T ¹ is an electron emitting group and T ² is an electron emitting group. It is more preferable that it is an aspirator. Specifically, T ¹ and T ² are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, an amino group having one or two alkyl groups having 1 to 6 carbon atoms, Alternatively, it is preferably an amino group or a trifluoromethyl group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms. In particular, in order to be incorporated into a high-order liquid crystal structure such as smectic liquid crystal, the molecule Since it is necessary to have a structure with a smaller exclusion volume, an alkyl group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, a cyano group, an amino group with 1 or 2 alkyl groups with 1 to 6 carbon atoms, or two substituted An amino group in which alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms is preferable.

Examples of such azo dyes include the following.

[Formula 5]

[Formula 6]

[In formulas (2-1) to (2-6), B ¹ to B ²⁰ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a nitro group, It represents a substituted or unsubstituted amino group (the definitions of substituted amino group and unsubstituted amino group are as described above), chlorine atom, or trifluoromethyl group. Moreover, 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.

When n1 is 2 or more, the plurality of B ² may be the same or different,

When n2 is 2 or more, a plurality of B ⁶ may be the same or different,

When n3 is 2 or more, the plurality of B ^9s may be the same or different,

When n4 is 2 or more, a plurality of B ¹⁴ may be the same or different.

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

[Formula 7]

[In formula (2-7), R ¹ to R ⁸ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

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

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

[Formula 8]

[In formula (2-8), R ⁹ to R ¹⁵ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.]

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

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

[Formula 9]

[In formula (2-9), R ¹⁶ to R ²³ each independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom.

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

In formulas (2-7), (2-8) and (2-9), the alkyl group having 1 to 4 carbon atoms represented by R ^x is methyl group, ethyl group, propyl group, butyl group, pentyl group or A hexyl group, etc. are mentioned, and examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, toluyl group, xylyl group, or naphthyl group.

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

[Formula 10]

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

[Formula 11]

n5 represents an integer from 1 to 3.]

[Formula 12]

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

[Formula 13]

n6 represents an integer from 1 to 3.]

The content of the dichroic dye (ratio of the total amount when multiple types are included) is, like the first region 11a of the liquid crystal layer 11, from the viewpoint of obtaining good light absorption characteristics, the visibility correction polarization degree (Py) In a region having a high polarization characteristic of 90% or more, the amount is generally preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, and 3 to 15 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound. It is more desirable. 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 alignment of the liquid crystal molecules may be impaired. In a region with low polarization characteristics such as the second region 11b of the liquid crystal layer 11, where the visibility-corrected polarization degree (Py) is 10% or less, the amount is usually 0 to 20 parts by mass per 100 parts by mass of the polymerizable liquid crystal compound. It is preferable that it is 0 to 10 parts by mass, and it is more preferable that it is 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 orientation layer 12 or the polarizing layer 21, which will be described later, when producing the polarizing film 1, for example, as described later. It can be used to support the liquid crystal layer (11) of (1).

Although the base material layer 13 may be a glass base material or a resin base material, it is preferable that it is a resin base material. Moreover, since the polarizing film 1 can be manufactured continuously, it is more preferable that the base material layer 13 is obtained by unwinding a long resin base material wound into a roll shape. The resin substrate is preferably a substrate that has transparency that can transmit visible light. Here, light transmittance refers to a visibility-corrected single transmittance of 80% or more for 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 that can be handled practically, but if it is too thin, the strength tends to decrease and workability tends to be poor. The thickness of the base material layer 13 is usually 5 μm to 300 μm, and preferably 20 μm to 200 μm. In addition, the base material layer 13 may be formed to be peelable, and for example, the liquid crystal layer 11 of the polarizing film 1 may be bonded to a member constituting a display device or a retardation layer described later. After doing so, it may be one that can be peeled off from the polarizing film (1). Accordingly, an additional thinning effect of the polarizing film 1 is obtained.

Resins constituting the resin substrate include, for example, polyolefins such as polyethylene and polypropylene; Cyclic olefin resins such as norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; Polymethacrylic acid ester; Polyacrylic acid ester; Cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide; etc. can be mentioned.

Commercially available cellulose ester resin substrates include "Fuji Tak Film" (manufactured by Fuji Photo Film Co., Ltd.); Examples include "KC8UX2M", "KC8UY", and "KC4UY" (manufactured by Konica Minolta Opto Co., Ltd.).

Commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "Aton" (registered trademark) (manufactured by JSR Corporation), and "ZEONOR" (registered trademark). , “ZEONEX” (registered trademark) (manufactured by Nippon Zeon Co., Ltd.), and “Apel” (registered trademark) (manufactured by Mitsui Chemicals Co., Ltd.). Such a cyclic olefin resin can be formed into a film by known means such as solvent casting or melt extrusion to form a resin substrate. A resin base material of a commercially available cyclic olefin resin can also be used. Resin base materials for commercially available cyclic olefin resins include "Scina" (registered trademark), "SCA40" (registered trademark) (manufactured by Sekisui Chemical Industry Co., Ltd.), and "Zeonoa Film" (registered trademark) ( Optes Co., Ltd.) and “Aton Film” (registered trademark) (manufactured by JSR Co., Ltd.).

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

Additionally, 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 circular polarizing plate function can be obtained by combining the base material layer 13 and the liquid crystal layer 11. Accordingly, a circularly polarizing plate can be obtained without bonding a retardation layer having a quarter wave plate function separately from the base material layer 13 to the polarizing film 1. In addition, when the base layer 13 has a multilayer 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 formed as a 1/2 wave plate. By laminating the functional layer on the side, a circularly polarizing plate can be obtained. Alternatively, when the base layer 13 has a multilayer structure, a circularly polarizing plate can be obtained by using a layer having a reverse wavelength dispersion 1/4 wave plate function and a layer having a positive C plate function laminated.

(Orientation layer)

The polarizing film 1 may have an orientation layer 12 on the base material layer 13, and the orientation layer 12 is disposed between the base material layer 13 and the liquid crystal layer 11. The alignment layer 12 may have an orientation regulating force that allows the liquid crystal compound in the liquid crystal layer 11 laminated thereon to be aligned in a desired direction.

The alignment layer 12 facilitates liquid crystal alignment of the liquid crystal compound. The state of liquid crystal alignment, such as horizontal alignment, vertical alignment, hybrid alignment, and oblique alignment, varies depending on the properties of the alignment layer 12 and the liquid crystal compound, and their combination can be arbitrarily selected. For example, if the alignment layer 12 is a material that exhibits horizontal alignment as an orientation regulating force, the liquid crystal compound can form a horizontal alignment or a hybrid alignment, and if the alignment layer 12 is a material that exhibits vertical alignment, the liquid crystal compound can form a horizontal alignment or a hybrid alignment. The compounds can form a vertical or oblique orientation. Expressions such as horizontal and vertical indicate the direction of the long axis of the aligned liquid crystal compound when the polarizing film (1) plane is referenced. For example, vertical alignment means having the long axis of the polymerizable liquid crystal oriented in a direction perpendicular to the plane of the polarizing film (1). Perpendicular here means 90° ± 20° with respect to the plane of the polarizing film (1). Since the polarizing film 1 preferably has polarization characteristics in the plane of the polarizing film 1, the orientation layer 12 is preferably formed using a material that exhibits horizontal orientation.

The orientation regulating force of the orientation layer 12 can be arbitrarily adjusted depending on the surface state and rubbing conditions when the orientation layer 12 is formed from an orientation polymer, and when the orientation layer 12 is formed from a photo-orientation polymer, the polarization It is possible to arbitrarily adjust it depending on investigation conditions, etc. Additionally, liquid crystal orientation can be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

The thickness of the orientation layer 12 is usually 10 nm to 5000 nm, preferably 10 nm to 1000 nm, and more preferably 30 nm to 300 nm. In addition, 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 It is desirable to have heat resistance in heat treatment for solvent removal or liquid crystal orientation.

Examples of the alignment layer 12 include an alignment film made of an orientation polymer, a photo-alignment film, or a groove orientation film. When the base material layer 13 is unwound from a roll-shaped elongated resin base material, the alignment layer 12 is preferably a photo-alignment film because its orientation direction can be easily controlled.

Orienting polymers include polyamides and gelatins that have an amide bond in the molecule, polyimides that have an imide bond in the molecule, polyamic acid that is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, and polyoxa. Sol, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, or polyacrylic acid esters can be mentioned. Among them, polyvinyl alcohol is preferable. These orientation polymers may be used individually, or may be used in combination of two or more types.

The alignment film made of an alignment polymer is usually created by applying a composition in which the alignment polymer is dissolved in a solvent (hereinafter sometimes referred to as “orientation polymer composition”) to the base layer 13 and removing the solvent, or It can be obtained by applying the oriented polymer composition to the base material layer 13, removing the solvent, and rubbing (rubbing method).

Solvents used in the orientation 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; Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, or ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, or methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as pentane, hexane, or heptane; Aromatic hydrocarbon solvents such as toluene or xylene, nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran or dimethoxyethane; Chlorine-substituted hydrocarbon solvents such as chloroform or chlorobenzene; etc. can be mentioned. These solvents may be used individually, or may be used in combination of two or more types.

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

As the alignment polymer composition, a commercially available alignment film material may be used as is. Commercially available alignment film materials include SanEVA (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.) or Optomer (registered trademark) (manufactured by JSR Corporation).

Methods for applying the oriented polymer composition to the base layer 13 include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, or applicator methods, and printing methods such as flexo. Known methods such as these can be mentioned. When the polarizing film 1 is manufactured by a roll-to-roll continuous manufacturing method, a printing method such as a gravure coating method, a die coating method, or a flexographic method can be generally adopted as the application method.

By removing the solvent contained in the orientation polymer composition, a dry film of the orientation polymer is formed. Methods for removing the solvent include natural drying, ventilation drying, heat drying, and reduced pressure drying. Thereafter, the dried film can be brought into contact with a rotating rubbing roll wound with a rubbing cloth to form the orientation layer 12.

The photo-alignment layer is usually an alignment layer formed by coating the base material layer 13 with a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter sometimes referred to as “composition for forming a photo-alignment layer”). It can be obtained by irradiating polarized light (preferably polarized UV) to the coating layer. A photo-alignment film is more preferable because 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 refers to a group that produces liquid crystal alignment ability by irradiating light. Specifically, it causes orientation of molecules that occurs by irradiating light, or causes a photo reaction that is the origin of the liquid crystal alignment ability, such as an isomerization reaction, dimerization reaction, photo cross-linking reaction, or photo decomposition reaction. Among the photoreactive groups, those that cause dimerization reaction or photocrosslinking reaction are preferable because they have excellent orientation. The photoreactive group capable of causing the above reaction preferably has an unsaturated bond, especially a double bond, such as carbon-carbon double bond (C=C bond), carbon-nitrogen double bond (C=N bond), nitrogen - A group having at least one selected from the group consisting of a nitrogen double bond (N=N bond) and a carbon-oxygen double bond (C=O bond) is more preferable.

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyene group, a stilbene group, a stilbazol group, a stilbazolium group, a chalcone group, or a cinnamoyl group. From the viewpoint of ease of control of reactivity and expression of orientation regulation force during photo-alignment, it is preferable that it is a chalcone group or a cinnamoyl group. Examples of the photoreactive group having a C=N bond include groups having structures such as an aromatic Schiff base or an aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, azonaphthalene group, aromatic heterocyclic azo group, bisazo group, or forma residue, and those having azoxybenzene as the basic structure. Examples of the photoreactive group having a C=O bond include a benzophenone group, coumarin group, anthraquinone group, or maleimide group. These groups may have a substituent such as an alkyl group, alkoxy group, aryl group, allyloxy group, cyano group, alkoxycarbonyl group, hydroxyl group, sulfonic acid group, or halogenated alkyl group.

The solvent for the composition for forming a photo-alignment film is preferably one that dissolves a polymer and a monomer having a photo-reactive group, and examples of the solvent include the solvents exemplified as solvents for the above-mentioned alignment polymer composition.

The content of the polymer or monomer having a photo-reactive group in the composition for forming a photo-alignment film can be appropriately adjusted depending on the type of the polymer or monomer having the photo-reactive group or the thickness of the photo-alignment film to be manufactured, but should be 0.2% by mass or more. It is preferable, and the range of 0.3 to 10 mass% is particularly preferable. Additionally, as long as the properties of the photo-alignment film are not significantly impaired, polymer materials such as polyvinyl alcohol or polyimide or a photosensitizer may be contained.

As a method of applying the composition for forming a photo-alignment film to the base material layer 13, the same method as the method of applying the above-mentioned alignment polymer composition to the base material layer 13 can be used. Examples of the method for removing the solvent from the coated composition for forming a photo-alignment film include the same method as the method for removing the solvent from the alignment polymer composition.

Polarized light irradiation may be performed directly on the dry film from which the solvent has been removed from the composition for forming a photo-alignment film coated on the base layer 13, and the polarized light that has transmitted through the base layer 13 may be applied to the base layer 13 so that the dried film is irradiated. ) may be carried out from the side. Moreover, it is particularly preferable that the polarized light used for polarized light irradiation is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range where the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength in the range of 250 to 400 nm is particularly preferable. Light sources used for polarization irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high-pressure mercury lamps, or metal halide lamps. It is more desirable. These lamps are preferable because they have a high emission intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by irradiating light from a light source through an appropriate polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glenn Thompson or Glenn Taylor, or a wire grid type polarizer can be used.

Additionally, if masking is performed when rubbing or polarized light irradiation is performed, a plurality of regions (patterns) with different liquid crystal orientation directions can be formed.

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

Methods for obtaining a groove alignment film include exposing the surface of a photosensitive polyimide film through an exposure mask having pattern-shaped slits, followed by development and rinsing to form a convex-convex pattern, and using a plate-shaped disk with grooves on the surface. A method of forming a layer of UV-curable resin before curing, transferring the resin layer to a substrate, and then curing the film, in which a roll-shaped disk having a plurality of grooves is pressed against the film of UV-curable resin before curing formed on the substrate to form an uneven surface. A method of forming and then curing may be included. Specifically, the method described in Japanese Patent Application Laid-Open No. 6-34976 and Japanese Patent Application Publication No. 2011-242743, etc. can be mentioned.

In order to obtain an orientation with small orientation disturbance, the width of the convex portion of the groove alignment film is preferably 0.05 μm to 5 μm, the width of the concave portion is preferably 0.1 μm to 5 μm, and the depth of the uneven step is preferably 2 μm or less. and is preferably 0.01 ㎛ to 1 ㎛ or less.

(Other floors)

The polarizing film 1 may have layers other than the base material layer 13 and the orientation layer 12. For example, a surface protective layer may be formed on the surface of the liquid crystal layer 11 opposite to the base material layer 13 for the purpose of protecting the surface of the liquid crystal layer 11. In addition, when peeling and using the base material layer 13, a surface protective layer may be formed on the surface of the liquid crystal layer 11 on the side from which the base material layer 13 was peeled. The surface protective layer may have a single-layer structure or a multi-layer structure. When the surface protective layer has a multilayer structure, each layer may be formed of the same material or may be formed of different materials.

＜Circular polarizer＞

2(a) to 2(c) are schematic cross-sectional views each showing an example of the circular polarizing plate of the present invention. The polarizing film 1 shown in Fig. 1(b) is converted into the circular polarizing plates 5a and 5b shown in Figs. 2(a) and 2(b) by laminating the retardation layer 15 having a quarter wave plate function. can do. The retardation layer 15 may be laminated on the liquid crystal layer 11 side of the polarizing film 1 (Fig. 2(a)) or may be laminated on the base layer 13 side (Fig. 2(b)). Additionally, the base material layer 13 peeled from the circularly polarizing plate 5a shown in FIG. 2(a) can also be used as the circularly polarizing plate 5c (FIG. 2(c)). In this case, the base material layer 13 The orientation layer 12 may also be peeled off.

Additionally, the circularly polarizing plate may be a product in which the polarizing film 1 and a retardation layer having a multilayer structure are laminated. In this case, as a retardation layer with a multi-layer structure, a retardation layer in which a layer with a 1/2 wave plate function and a layer with a 1/4 wave plate function can be laminated, and the 1/2 wave plate of the retardation layer with a multi-layer structure can be used. By laminating the functional layer side and the polarizing film 1, a circularly polarizing plate can be obtained. Alternatively, a circularly polarizing plate can be obtained by using a retardation layer of a multilayer structure in which a layer having a 1/4 wave plate function with reverse wavelength dispersion and a layer having a positive C plate function are laminated.

Additionally, a material having a function as a retardation layer may be used as the base layer 13 of the polarizing film 1, and a retardation layer may be further laminated to form a circularly polarizing plate. In this case, the function of the base layer 13 and the retardation layer as a retardation layer may be selected depending on the lamination position of the base layer 13 and the retardation layer in the circularly polarizing plate.

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

＜Manufacturing method of polarizing film (first manufacturing method)＞

FIGS. 3(a) to 3(d) are schematic cross-sectional views showing the layer structure obtained in each step of the manufacturing process of the polarizing film 1 shown in FIG. 1(b). The first manufacturing method of the polarizing film (1) is:

A preparation 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 layer 13;

By contacting a partial region of the polarizing layer 21 of the laminated film 62 with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer 21, It has a liquid contact process to reduce the content of dichroic dye.

The liquid contact process involves forming, on the polarizing layer 21 of the laminated film 62, a covering area 35a for covering the polarizing layer 21 and an exposure area 35b for exposing the polarizing layer 21. A protective layer lamination process of obtaining a protective layer forming laminated film 63 (FIG. 3(c)) by laminating the protective layer 35 having,

By bringing the protective layer forming laminated film 63 into contact with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer 21, the content of the dichroic dye in a partial region of the polarizing layer 21 is reduced. A decolorization process to obtain a decolorized laminated film 64 (FIG. 3(d)),

There is a peeling process of peeling the protective layer 35 from this decolorizing laminated film 64, and thereby the polarizing film 1 shown in FIG. 1(b) can be manufactured.

(preparation process)

The laminated film 62 prepared in the preparation process 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 as shown in FIG. 3(b), the base material layer 13 It is preferable that the orientation layer 12 and the polarizing layer 21 are laminated in this order. Such a laminated film 62 is formed by coating a composition for forming an orientation layer on one side of the base layer 13 to form an orientation layer 12, thereby forming an orientation layer forming base layer 61 (FIG. 3(a)). an orientation layer forming step to obtain a polarizing layer forming step, and a polarizing layer forming step to form the polarizing layer 21 by coating a polarizing layer forming composition on the surface of the orientation layer forming base layer 61 on the side where the orientation layer 12 is formed. It can be manufactured through

In the orientation layer forming step, the base material layer 13 may be subjected to surface treatment before coating the composition for forming the orientation layer. Examples of surface treatment methods include corona treatment, plasma treatment, laser treatment, ozone treatment, saponification treatment, flame treatment, coupling agent application treatment, and primer treatment. As the composition for forming an alignment layer, the above-described alignment polymer composition, a composition for forming a photo-alignment layer, a composition containing a resin material for forming a groove alignment layer, etc. can be used. The method of forming an orientation layer using each composition is the same as described above. For example, when the composition for forming an orientation layer contains a photo-alignable polymer, the orientation layer forming process is performed by applying polarized light irradiation to the coating layer for an orientation layer formed by coating the composition for forming an orientation layer, thereby providing an orientation regulating force in a predetermined direction. An orientation layer having can be formed.

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

Methods for coating the composition for forming a polarizing layer include extrusion coating, direct gravure coating, reverse gravure coating, CAP coating, slit coating, micro gravure, die coating, and inkjet methods. Additionally, a method of coating using a coater such as a dip coater, bar coater, or spin coater can also be mentioned. Among them, when coating continuously in a roll to roll format, a coating method using a microgravure method, inkjet method, slit coating method, or die coating method is preferable, and when coating on a sheet wafer substrate such as glass, uniformity This high spin coating method is preferred. In the case of coating in a roll to roll format, a composition for forming an orientation film, etc. is applied to the base layer 13 to form an orientation layer 12, and the composition for forming a polarizing layer is continuously applied on the obtained orientation layer 12. You may.

When forming the polarizing layer 21 by applying the polarizing layer forming composition, the solvent is removed from the applied 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 orientation polymer composition can be used, for example, natural drying, ventilation drying, heat drying, reduced pressure drying, and a combination of these methods. Among them, natural drying or heat drying are 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 process is irradiated with active energy rays, and the polymerizable liquid crystal compound is photopolymerized to produce a polymerizable liquid crystal compound. It is desirable to form the polarizing layer 21 as a polymer layer. The active energy ray to be irradiated includes the type of polymerizable liquid crystal compound contained in the coating layer for the polarizing layer (particularly, the type of photopolymerizable functional group that the polymerizable liquid crystal compound has) and, if a photopolymerization initiator is included, the type of photopolymerization initiator. They are appropriately selected depending on their type and quantity. Specifically, one or more types 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 because it is possible to use a photopolymerization device widely used in the field, and polymerization is possible so that photopolymerization is possible with ultraviolet light. It is desirable to select the type of liquid crystal compound.

Light sources of active energy rays include, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and wavelength ranges of 380 to 380. Examples include an LED light source that emits light at 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The irradiation intensity of active energy rays is usually 10 mW/cm2 to 3000 mW/cm2. The irradiation intensity of the active energy ray is preferably an intensity in the wavelength range effective for activation of the cationic polymerization initiator or radical polymerization initiator. The time for irradiating active energy rays is usually 0.1 second to 10 minutes, preferably 0.1 second to 5 minutes, more preferably 0.1 second to 3 minutes, and even more preferably 0.1 second to 1 minute. When irradiated with such an irradiation intensity of active energy rays once or multiple times, the accumulated amount of light is 10 mJ/cm2 to 3000 mJ/cm2, preferably 50 mJ/cm2 to 2,000 mJ/cm2, more preferably 100 mJ. It can be /㎠ ~ 1000 mJ/㎠. If the accumulated light amount is below this range, curing of the polymerizable liquid crystal compound may become insufficient and good transferability may not be obtained. Conversely, when the accumulated light amount is above this range, the polarizing layer may be colored.

(solvent)

The composition for forming a polarizing layer may contain a solvent. In general, polymerizable liquid crystal compounds have high viscosity, so when using a polymerizable liquid crystal compound as a liquid crystal compound, coating is facilitated by using a composition for forming a polarizing layer containing a solvent, and as a result, it is easy to form a polarizing layer. Lose. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound and the dichroic dye, and is also preferably inert in 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; Ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, or ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, or methyl isobutyl ketone; Aliphatic hydrocarbon solvents such as pentane, hexane, or heptane; Aromatic hydrocarbon solvents such as toluene or xylene, nitrile solvents such as acetonitrile; Ether solvents such as tetrahydrofuran or dimethoxyethane; Chlorine-containing solvents such as chloroform or chlorobenzene; and amide-based solvents such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. These solvents may be used individually, or may be used in combination of two or more types.

The content of the solvent contained in the composition for forming a polarizing layer is preferably 50 to 98% by mass with respect to the total amount of the composition for forming a polarizing layer. In other words, the solid content in the composition for forming a polarizing layer is preferably 2 to 50 mass%. If the solid content is 50% by mass or less, the viscosity of the composition for forming the polarizing layer is lowered, so the thickness of the polarizing layer 21 becomes substantially uniform, and unevenness tends to occur less easily in the polarizing layer 21. In addition, the content of this solid content can be determined by considering 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 of the polymerizable liquid crystal compound or the like. The polymerization initiator is preferably a photopolymerization initiator that generates active radicals by the action of light from the viewpoint of not being dependent 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, and sulfonium salts.

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

Examples of benzophenone compounds include benzophenone, o-benzoylmethyl benzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra ( tert-butylperoxycarbonyl)benzophenone and 2,4,6-trimethylbenzophenone.

Examples of alkylphenone compounds include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, and 2-benzyl-2-dimethylamino-1. -(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethane-1- one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexylphenylketone or 2-hydroxy-2-methyl- and oligomers of 1-[4-(1-methylvinyl)phenyl]propan-1-one.

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

Triazine compounds include, for example, 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl) -6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-tri Azine, 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl )-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino- 2-methylphenyl)ethenyl]-1,3,5-triazine or 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3, 5-triazine, etc. can be mentioned.

A commercially available polymerization initiator 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 Chiba Specialty Chemicals Co., Ltd.) ) ; Seikol (registered trademark) BZ, Z, or BEE (manufactured by Seiko Chemical Co., Ltd.); Kayacure (registered trademark) BP100, or UVI-6992 (manufactured by Dow Chemical Co., Ltd.); Adeka Optomer SP-152, N-1717, N-1919, SP-170, Adeka Aclus NCI-831, Adeka Aclus NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A, or TAZ-PP (manufactured by Japan Siebel Hegner Co., Ltd.); TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.); etc. can be mentioned. One type of polymerization initiator in the composition for forming a polarizing layer may be used, or two or more types of polymerization initiators may be mixed and used according to the light source.

The content of the polymerization initiator in the composition for forming a polarizing layer can be appropriately adjusted depending on the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 to 30 parts by mass, preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the content of the polymerizable liquid crystal compound. is 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass. If the content of the polymerization initiator is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

(Sensitizer)

The composition for forming a polarizing layer may contain a sensitizer. The sensitizer 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 preferably a photosensitizer. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); Anthracene compounds such as anthracene and alkoxy group-containing anthracene (for example, dibutoxyanthracene, etc.); Phenothiazine or rubrene can be mentioned.

When the composition for forming a polarizing layer contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming a polarizing layer 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 still more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound.

(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 suitably used when a polymerizable liquid crystal compound is used as the liquid crystal compound, and the progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

Polymerization inhibitors include, for example, hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (e.g., butylcatechol, etc.), pyrogallol, and 2,2,6,6-tetramethyl-1-pipe. Radical scavengers such as ridinyloxy radical; Thiophenols; Examples include β-naphthylamines or β-naphthols.

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 0.5 to 5 parts by mass, based on 100 parts by mass of the content of the polymerizable liquid crystal compound. part, more preferably 0.5 to 3 parts by mass. If the content of the polymerization inhibitor is within the above range, polymerization can be performed without disturbing the orientation of the polymerizable liquid crystal compound.

(Leveling system)

The composition for forming a polarizing layer may contain a leveling agent. A leveling agent is an additive that has the function of adjusting the fluidity of the composition and making the film obtained by applying the composition more flat. For example, an organic modified silicone oil-based, polyacrylate-based, or perfluoroalkyl-based leveling agent. can be mentioned. 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. , Manufactured by Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all manufactured by Sumitomo 3M Co., Ltd.), Megapak (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 (above, all manufactured by DIC Co., Ltd.), F-top (product name) EF301, EF303, EF351, EF352 (above, all manufactured by Mitsubishi Material Electronics Co., Ltd.), Suplon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40, SA-100 (all AGC Semi Chemicals) (manufactured by Daikin Fine Chemical Laboratories Co., Ltd.), brand name E1830, E5844 (manufactured by Daikin Fine Chemical Laboratories Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 or BYK-361N (all brand names: manufactured by BM Chemie Co., Ltd.) ), etc. Among them, polyacrylate-based leveling agents or perfluoroalkyl-based leveling agents are preferable.

When the composition for forming a polarizing layer contains a leveling agent, the amount is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass, based on 100 parts by mass of the liquid crystal compound. It is wealth. If the content of the leveling agent is within the above range, it is easy to horizontally align the liquid crystal compound, and the resulting polarizing layer tends to become smoother. If the content of the leveling agent in the liquid crystal compound exceeds the above range, unevenness tends to occur in the resulting polarizing layer. Additionally, the composition for forming a polarizing layer may contain two or more types of leveling agents.

(reactive additive)

The composition for forming a polarizing layer may contain a reactive additive. The reactive additive preferably has a carbon-carbon unsaturated bond and an active hydrogen reactive group in its molecule. In addition, the “active hydrogen reactive group” herein refers to a group that is reactive toward groups having active hydrogen such as carboxyl group (-COOH), hydroxyl group (-OH), and amino group (-NH ₂ ), and glycidyl group and oxa group. Representative examples include sleepy group, carbodiimide group, aziridine group, imide group, isocyanate group, thioisocyanate group, and maleic anhydride group. The number of carbon-carbon unsaturated bonds or active hydrogen reactive groups that the reactive additive has 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 exist. In this case, multiple active hydrogen reactive groups may be the same or different.

The carbon-carbon unsaturated bond possessed by 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 these, the reactive additive preferably contains a carbon-carbon unsaturated bond as a vinyl group and/or (meth)acrylic group. Furthermore, 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 acryloxyglycidyl ether; Compounds having a (meth)acrylic group and an oxetane group, such as oxetane acrylate and oxetane methacrylate; Compounds having a (meth)acrylic group and a lactone group, such as lactone acrylate and lactone methacrylate; Compounds having a vinyl group and an oxazoline group, such as vinyloxazoline and isopropenyloxazoline; Oligomers of compounds having a (meth)acrylic group and an isocyanate group, such as isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate, or 2-isocyanatoethyl methacrylate, etc. You can. Moreover, compounds having a vinyl group, a vinylene group, and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, or vinyl maleic anhydride, can be mentioned. Among them, methacryloxyglycidyl ether, acryloxyglycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyloxazoline, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl. Methacrylate or the above oligomers are preferred, and isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate or the above oligomers are particularly preferred.

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

[Formula 14]

[In formula (Y), n represents an integer from 1 to 10, and R ^1' represents a divalent aliphatic or alicyclic hydrocarbon group with 2 to 20 carbon atoms, or a divalent aromatic hydrocarbon group with 5 to 20 carbon atoms. One of the two R ^2' in each repeating unit is -NH-, and the other is a group represented by >NC(=O)-R ^3' . R ^3' represents a hydroxyl group or a group having a carbon-carbon unsaturated bond.

Among R ^3' in formula (Y), at least one R ^3' is a group having a carbon-carbon unsaturated bond.]

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

[Formula 15]

Compound (YY) can be used as a commercial product as is or after purifying as necessary. Commercially available products include, for example, Laromer (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 to 5 parts by mass, based on 100 parts by mass of the liquid crystal compound.

(Protective layer lamination process)

In the protective layer lamination process, as shown in FIG. 3(c), a covering area 35a for covering the polarizing layer 21 is formed on the polarizing layer 21 of the laminated film 62 prepared in the preparation process, A protective layer 35 having an exposed area 35b for exposing the polarizing layer 21 is laminated. In this way, the protective layer forming laminated film 63 can be obtained. The exposed area 35b can be, for example, an opening in the protective layer 35. The covering area 35a is such that when the liquid material capable of reducing the content of the dichroic dye in the polarizing layer 21 described later is brought into contact with the protective layer forming laminated film 63, the liquid material is in the polarizing layer 21. It can prevent contact with On the other hand, in the exposed area 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 a liquid material, the liquid material penetrates into the polarizing layer 21 and causes the dichroic dye to lose its function as a dye. Therefore, it is preferable that the exposed region 35b is formed to correspond to a region in the polarizing layer 21 that reduces the content of the dichroic dye. For example, when manufacturing the polarizing film 1 shown in FIGS. 1(a) and 1(b), it is preferable to determine the shape according to the shape of the second region 11b. For example, the shape of the second area 11b when viewed from the plane is circular; oval; Wonhyeong Jang; Polygons such as triangles, squares, squares, and diamonds; line shape ; band shape; If it has a wave shape or the like, the exposed area 35b may be formed corresponding to these shapes.

For example, when the exposed area 35b is circular, its diameter is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the exposed area 35b is oval or oblong, its major 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 even more preferably 2 cm or less. As will be described later, since the liquid substance penetrates into the liquid crystal layer, the size of the exposed area 35b may not be the same as that of the second area 11b but may be slightly smaller.

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

As the protective layer 35, a sheet-like substrate in which an area to be the exposed area 35b is formed can be used. The area becoming the exposed area 35b is formed by mechanically punching out a predetermined portion of the sheet-like substrate by punching, cutting plotter, water jet, etc., or by removing a predetermined portion of the sheet-like substrate by laser ablation, chemical dissolution, etc. It can be formed by methods, etc.

The sheet-like substrate forming the protective layer 35 is insoluble in the liquid when brought into contact with a liquid that can reduce the content of the dichroic dye in the liquid crystal layer described later, and can be used to remove the liquid, The material is not particularly limited as long as it has durability against ultraviolet irradiation applied after contact with a liquid substance. As the sheet-like substrate forming the protective layer 35, for example, it can be formed using the same material as the above-mentioned substrate layer 13, and it is especially preferable to use a resin substrate, and the protective layer It is more preferable to use a polyester resin such as polyethylene terephthalate that is easy to suppress deformation of the area (for example, the opening) that becomes the exposed area 35b of (35).

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

(decolorization process)

In the decolorization process, the protective layer forming laminated film 63 obtained in the protective layer lamination process is brought into contact with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer 21, thereby forming the polarizing layer 21. A decolorized laminated film 64 in which the content of the dichroic dye was reduced in some areas could be obtained (FIG. 3(d)). Since the protective layer 35 of the protective layer forming laminated film 63 has a covering area 35a for covering the polarizing layer 21 and an exposed area 35b for exposing the polarizing layer 21, The liquid substance and the polarizing layer 21 can be brought into contact in the exposed area 35b. Accordingly, the content of the dichroic dye can be reduced in the area of the polarizing layer 21 in contact with the liquid substance.

The contact between the protective layer-forming laminated film 63 and the liquid material is carried out by immersing the protective layer-forming laminated film 63 in the liquid material, or by applying, spraying, or dropping the liquid material on the protective layer-forming laminated film 63. This can be done, and is preferably carried out by immersing the protective layer forming laminated film 63 in a liquid substance. Accordingly, the liquid comes into contact with the surface of the polarizing layer 21 exposed from the exposed area 35b of the protective layer 35, and penetrates into the inside of the polarizing layer 21. Although the details are not clear, the liquid substance that has penetrated into the inside of the polarizing layer 21 decomposes the dichroic dye in the polarizing layer 21 or reacts with the dichroic dye, thereby losing the function of the dichroic dye as a dye. I think it is ordered. Accordingly, the second region 11b, which is a region with a lower content of dichroic dye than other regions, is formed in a part of the polarizing layer 21, thereby forming a decolorized laminated film 64 having the liquid crystal layer 11 (FIG. 3 (d)) can be obtained.

Of the surface of the polarizing layer 21, the area covered by the covering area 35a of the protective layer 35 is a region where liquid substances are not present in the polarizing layer 21 because the polarizing layer 21 is not in direct contact with the liquid substance. It is difficult to penetrate and dichroic pigments are difficult to disappear. On the other hand, in the area of the polarizing layer 21 exposed from the exposed area 35b of the protective layer 35, the polarizing layer 21 is in direct contact with the liquid material, so the liquid material is not present in the polarizing layer 21. It is easy to penetrate and the dichroic pigment is easy to disappear. Therefore, in the decolorizing laminated film 64 shown in FIG. 3(d), the region corresponding to the exposed region 35b in the polarizing layer 21 is a low polarization region in which the content of the dichroic dye is smaller than other regions. A liquid crystal layer 11 having two regions 11b can be formed.

In this way, by using the protective layer forming laminated film 63 in which the exposed area 35b of the protective layer 35 is disposed in the area of the polarizing layer 21 where the content of the dichroic dye is to be reduced, the polarizing layer 21 ) It is possible to form a liquid crystal layer 11 with a reduced content of dichroic dye at a desired position. However, since the liquid substance penetrates into the inside of the polarizing layer 21 and loses the function of the dichroic dye, the liquid substance penetrates into areas where it is not necessary to reduce the content of the dichroic dye, thereby lowering the content of the dichroic dye. The thickness of the protective layer 35, the size of the exposed area 35b, the concentration of the liquid material, the immersion time of the protective layer-forming laminated film with respect to the liquid material, and the liquid water with respect to the protective layer-forming laminated film 63 are It is desirable to adjust the application amount, spray amount, or dripping amount.

The liquid material capable of reducing the content of the dichroic dye in the polarizing layer 21 is not particularly limited as long as it can reduce the content of the dichroic dye, but examples include peroxide (hydrogen peroxide, sodium percarbonate, etc.) Chlorine compounds (sodium hypochlorite, etc.), acids (sulfuric acid, nitric acid, hexafluorophosphoric acid), alkalis (sodium hydroxide, potassium hydroxide), etc. can be used appropriately. Among them, acids such as sulfuric acid, nitric acid, and hexafluorophosphoric acid are preferable. These liquid substances may be used individually or in combination.

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

The decolorization process involves contacting the protective layer-forming laminated film 63 with a liquid substance to form a region in a part of the polarizing layer 21 with a lower content of dichroic dye than other areas, and then washing away the liquid substance. 1 It is desirable to provide a cleaning process. The first cleaning step can be performed using an organic solvent such as water or alcohol.

(Peeling process)

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

The polarizing film 1 shown in FIG. 1(b) can also be used by peeling the base material layer 13. In this case, the orientation layer 12 may also be peeled off along with the base material layer 13. For example, peeling of the base material layer 13 may be performed after bonding the liquid crystal layer 11 of the polarizing film 1 to a member or a retardation layer that constitutes a display device.

(Method for continuously manufacturing polarizing film)

The method for producing the polarizing film (1) is preferably continuous, using a roll to roll format. In this case, in the preparation process, a laminated film wound into a roll is prepared, the laminated film is conveyed while unwinding, and the protective layer lamination process, decolorization process, and peeling process are performed continuously. In the protective layer lamination process, the protective layer wound into a roll is conveyed while unwinding, and the protective layer is bonded to the laminated film to obtain a protective layer forming laminated film. In the decolorization process, the protective layer-forming laminated film is passed through a liquid bath filled with liquid water while continuously conveying the protective layer-forming laminated film, or the liquid material is applied, sprayed, or dropped while continuously conveying the protective layer-forming laminated film, thereby forming a decolorizing lamination. Just get the film. In the peeling process, the protective layer is continuously peeled from the decolorized laminated film, and the polarizing film is wound into a roll to form a wound body. The polarizing film continuously manufactured as described above may have a length of, for example, 10 m or more.

In addition, when the preparation process includes an orientation layer forming process, the base material layer wound into a roll is conveyed while unwinding, and the composition for forming an orientation layer is continuously applied to this base layer using a coating device to form an orientation layer. . When the preparation process includes a polarizing layer forming step, the polarizing layer forming composition is formed by coating the polarizing layer forming composition on the surface of the orientation layer forming base layer on the side where the orientation layer is formed while continuously conveying the orientation layer forming base layer. do.

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 made small, for example, 2 μm or less, so that the step difference is small. A polarizing film (1) without polarization can be obtained. Accordingly, even if another film is bonded to the polarizing layer 21 using an adhesive or the like, the other film can be laminated without mixing air bubbles.

＜Manufacturing method of polarizing film (second manufacturing method)＞

The polarizing film 1 can also be manufactured by the second manufacturing method shown below in addition to the first manufacturing method described above. FIG. 4 is a schematic cross-sectional view showing an example of a liquid substance contact step in the method for producing the polarizing film 1 shown in FIG. 1(b). The second manufacturing method of the polarizing film (1) is:

A preparation 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 layer 13;

By bringing a partial region of the polarizing layer 21 of the laminated film 62 into contact with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer 21, the dichroic dye in the partial region is reduced. There is a liquid substance contact process (FIG. 4) to reduce the content, and thereby the polarizing film 1 shown in FIGS. 1(a) and 1(b) can be manufactured.

The preparation process in this second manufacturing method is the same as the preparation process in the first manufacturing method described based on FIGS. 3(a) and 3(b). Through this preparation process, the laminated film 62 having the polarizing layer 21 is prepared.

In this second manufacturing method, a partial region of the polarizing layer 21 on the laminated film 62 is brought into contact with a liquid substance (FIG. 4). The liquid substance used at this time is capable of reducing the content of dichroic dye in some regions of the polarizing layer 21, and is the same liquid substance as the liquid substance used in the decolorization step in the first manufacturing method described above. You can use water. As a method of bringing a liquid substance into contact with a partial region of the polarizing layer 21, for example, as shown in FIG. 4, a so-called inkjet method is used in which the liquid substance is applied dropwise to this partial region. By bringing the polarizing layer 21 into contact with a liquid substance, the liquid substance penetrates into a partial 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 washing the liquid on the polarizing layer 21 after bringing the polarizing layer 21 into contact with the liquid. The second cleaning step can be performed using an organic solvent such as water or alcohol used in the first cleaning step in the first manufacturing method. Thereby, the polarizing film 1 shown in FIG. 1(b) can be obtained.

As for the second manufacturing method, the polarizing film 1 can be continuously manufactured, for example, in a roll to roll format, similar to the first manufacturing method. In this case, in the preparation process, a laminated film wound into a roll is prepared, the laminated film is conveyed while unwinding, and the liquid substance contact process is performed continuously. In the liquid material contact process, a liquid material is applied dropwise while continuously conveying the laminated film to obtain a polarizing film, and the obtained polarizing film is wound into a roll to form a wound body. The polarizing film continuously manufactured as described above may have a length of, for example, 10 m or more.

In addition, when the preparation process includes an orientation layer forming process, the base material layer wound into a roll is conveyed while unwinding, and the composition for forming an orientation layer is continuously applied to this base layer using a coating device to form an orientation layer. . When the preparation process includes a polarizing layer forming step, the polarizing layer forming composition is formed by coating the polarizing layer forming composition on the surface of the orientation layer forming base layer on the side where the orientation layer is formed while continuously conveying the orientation layer forming base layer. do.

Even with this second manufacturing method, the difference in thickness between the first region 11a and the second region 11b can be made small, for example, 2 μm or less, and a polarizing film 1 without any steps can be obtained. You can. Accordingly, even if another film is bonded to the polarizing layer 21 using an adhesive or the like, the other film can be laminated without mixing air bubbles.

＜Manufacturing method of circular polarizer＞

A circularly polarizing plate can be manufactured by laminating a polarizing film (1) and a retardation layer. As described above, when the polarizing film is a continuously manufactured long polarizing film with a length of 10 m or more, a long retardation layer with a length of 10 m or longer is used as the retardation layer, and the long polarizing film and the long retardation are formed while continuously conveying both. It is preferable to form a long laminated body by stacking layers. At this time, it is preferable to apply a pressure sensitive adhesive or adhesive to at least one of the long polarizing film and the long retardation layer and laminate them.

The manufacturing method of a circular polarizing plate may include a step of cutting a long laminate obtained by laminating a long polarizing film and a long retardation layer into sheet wafers of a predetermined size in order to mount the polarizing film on a display device of a predetermined size. In the cutting process, it is preferable to cut the long laminated body in at least one of the longitudinal direction and the width direction of the long laminated body. In this case, it is desirable to determine the cutting position in the elongated laminate so that the second region 11b of the liquid crystal layer 11 is placed at a predetermined position in the cut sheet.

Example

The present invention will be described in more detail based on examples. However, the present invention is not limited to these examples.

[Visibility-corrected polarization (Py) and visibility-corrected transmittance (Ty)]

(Preparation of samples for evaluation)

The composition for forming an orientation layer and the composition for forming a polarizing layer used in each Example, Comparative Example, and Reference Example were prepared. In addition, the same film used as the base material layer in each Example, Comparative Example, and Reference Example was cut into 40 mm × 40 mm and prepared as the base layer of the sample for evaluation. Using these, in Examples 1, 2, Comparative Examples, and Reference Examples, no protective layer was used, and in Example 3, instead of partially dropping the solution on the polarizing layer, the entire surface of the polarizing layer was brought into contact with the solution. Except this, the same procedure as the production of the polarizing film of each Example, Comparative Example, and Reference Example was performed to obtain a sample for evaluation.

(Visibility-corrected polarization (Py) and visibility-corrected transmittance (Ty))

For the evaluation sample, the visibility corrected single transmittance (Ty) and the visibility corrected polarization degree (Py) were calculated in the following procedure. The transmittance (T ₁ ) in the transmission axis direction and the transmittance (T ₂ ) in the absorption axis direction in the wavelength range of 380 nm to 780 nm were measured using a device in which a polarizer forming folder was set to a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation). It was measured using the double beam method. In that folder, a mesh was installed on the reference side to cut the amount of light by 50%. Using the following (Equation 1) and (Equation 2), the transmittance and polarization degree at each wavelength were calculated, and visibility correction was performed using the 2-degree field of view (C light source) of JIS Z 8701, and the visibility correction transmittance ( Ty) and visibility-corrected polarization degree (Py) were calculated.

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

Single transmittance [%] = (T ₁ + T ₂ )/2 (Equation 2)

[Example 1]

(Preparation of composition for forming orientation layer)

The following components were mixed, and the resulting 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 photo-alignment film.

· 2 parts of a polymer having a photoreactive group shown below

[Formula 16]

· Solvent: o-xylene 98 parts

(Preparation of composition for forming polarizing layer)

A composition for forming a polarizing layer was obtained by mixing the following components and stirring at 80°C for 1 hour. As the dichroic dye, the azo dye described in the examples of Japanese Patent Application Laid-Open No. 2013-101328 was used.

75 parts of polymerizable liquid crystal compound represented by formula (1-6)

[Formula 17]

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

[Formula 18]

・Dichroic dye shown below (1) 2.8 parts

[Formula 19]

・Dichroic dye shown below (2) 2.8 parts

[Formula 20]

· Dichroic dye (3) 2.8 parts shown below

[Formula 21]

・6 parts of polymerization initiator shown below

2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Chiba Specialty Chemicals)

・1.2 parts of leveling agent shown below

Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)

・250 parts of solvent shown below

Cyclopentanone

(Manufacture of polarizing film)

A triacetylcellulose film (KC4UY-TAC, manufactured by Konica Minolta, thickness 40 μm) as a base layer was cut into 20 × 20 mm, and corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) was applied to its surface. The composition for forming an orientation layer was applied to the corona-treated film surface using a bar coater, and then dried for 1 minute in a drying oven set at 120°C to obtain a coated layer for the orientation layer. Using a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Electric Co., Ltd.), polarized UV was irradiated at an accumulated light amount of 50 mJ/cm2 (based on 313 nm) on the coating layer for the orientation layer to form an orientation layer. . After apply|coating the composition for polarizing layer formation on the obtained orientation layer using a bar coater, it was dried for 1 minute in a drying oven set at 110 degreeC. After that, using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Electric Co., Ltd.), ultraviolet rays were irradiated (under nitrogen atmosphere, wavelength: 365 nm, integrated light amount at 365 nm: 1000 mJ/cm2). , a polarizing layer in which the liquid crystal compound and the dichroic dye were aligned was obtained. On the polarizing layer, a protective layer (AY-638 manufactured by Fujimori Kogyo Co., Ltd.) in which openings were formed by making holes with a hole punch. A 15-μm-thick adhesive layer was formed on a 38-μm-thick polyester film. ) was bonded, and then immersed in a 50 wt% solution of propylene carbonate of diphenyl 4-thiophenoxyphenylsulfonium hexafluorophosphate (CPI-100P, manufactured by San-Apro Co., Ltd.) at 120°C for 60 seconds. After that, the protective layer was peeled off to obtain a polarizing film.

As a result of observing the appearance of the obtained polarizing film with the naked eye, a circular region (low-polarization region) in which no polarizing layer exists was clearly confirmed, and it was found that a polarizing film having a polarization region and a low-polarization region was obtained. Additionally, a sample for evaluation was prepared in the above-mentioned procedure, and its visibility-corrected transmittance (Ty) and visibility-corrected polarization degree (Py) were calculated. The results are shown in Table 1.

[Example 2]

Instead of using a triacetylcellulose film as a base layer, 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 cyclic olefin resin, was applied to the surface. A polarizing film was obtained in the same manner as in Example 1, except that the hard coat-treated film was laminated so that the slow axis and the absorption axis of the polarizing layer were 45°. Additionally, a sample for evaluation was prepared in the above-mentioned procedure, and its visibility-corrected transmittance (Ty) and visibility-corrected polarization degree (Py) were calculated. The results are shown in Table 1.

[Example 3]

Instead of gluing the protective layer with an opening formed by making holes with a hole punch, diphenyl 4-thiophenoxyphenylsulfonium hexafluorophosphate (San Apro) is partially applied onto the polarizing layer using an eye dropper. 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 Co., Ltd.) was added dropwise. Additionally, a sample for evaluation was prepared in the above-mentioned procedure, and its visibility-corrected transmittance (Ty) and visibility-corrected polarization degree (Py) were calculated. The results are shown in Table 1.

[Comparative example]

In place of a 50 wt% propylene carbonate solution of diphenyl 4-thiophenoxyphenylsulfonium hexafluorophosphate (CPI-100P, manufactured by San-Apro Co., Ltd.), the same procedure as in Example 1 was used, except that methanol was used at room temperature. A polarizing film was obtained. As a result of observing the appearance of the obtained polarizing film with the naked eye, the area in which the polarizing layer did not exist could not be confirmed, and it was found that the polarizing film having a polarization region and a low polarization region was not obtained. Additionally, a sample for evaluation was prepared in the above-mentioned procedure, and its visibility-corrected transmittance (Ty) and visibility-corrected 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 diphenyl 4-thiophenoxyphenylsulfonium hexafluorophosphate (CPI-100P, manufactured by San-Apro Co., Ltd.) in propylene carbonate was not used. . As a result of observing the appearance of the obtained polarizing film with the naked eye, the area in which the polarizing layer did not exist could not be confirmed, and it was found that the polarizing film having a polarization region and a low polarization region was not obtained. Additionally, a sample for evaluation was prepared in the above-mentioned procedure, and its visibility-corrected transmittance (Ty) and visibility-corrected polarization degree (Py) were calculated. The results are shown in Table 1.

In addition, the values of visibility corrected transmittance (Ty) and visibility corrected polarization (Py) measured in each Example, Comparative Example, and Reference Example shown in Table 1 are the visibility corrected transmittance (Ty) and visibility corrected polarization degree of the base layer. Although the value includes the value of (Py), the visibility corrected transmittance (Ty) of the base layer alone is 92%, and the value of the visibility corrected polarization (Py) of the base layer is 0%, so each example shown in Table 1 , when the base layer is excluded in the comparative examples and reference examples, the value of the visibility corrected transmittance (Ty) becomes larger than the value shown in Table 1, and the value of the visibility corrected polarization degree (Py) becomes the same as the value shown in Table 1. I think so.

1: Polarizing film
5a to 5c: circular polarizer
11: liquid crystal layer
11a: first area
11b: second area
12: Orientation layer
13: Base layer
15: Phase difference layer
21: Polarizing layer
35: protective layer
35a: Covered area
35b: exposed area
61: alignment layer forming base layer
62: Laminated film
63: Laminated film forming protective layer
64: Decolorized laminated film

Claims (18)

A protective layer forming polarizing film having a polarizing film and a protective layer,
The length of the protective layer forming polarizing film is 10 m or more,
The polarizing film has a liquid crystal layer,
The liquid crystal layer is,
In addition to containing a liquid crystal compound,
At least two regions are distinguished by the value of the visibility correction polarization degree and have different content rates of the dichroic dye, a first region containing the dichroic dye and a second region having a content rate of the dichroic dye less than the first region. has in the same plane,
The liquid crystal compound is a thermotropic liquid crystal,
The difference between the thickness of the first region and the thickness of the second region is 0.5 μm or less,
The protective layer is,
is laminated adjacent to the liquid crystal layer, and
A polarizing film with a protective layer having a covering area for covering the first area and an exposed area for exposing the second area. According to claim 1,
The polarizing film further has a base layer and an orientation layer laminated on at least one side of the base layer,
A polarizing film with a protective layer, wherein the liquid crystal layer is laminated on the alignment layer. According to claim 2,
The orientation layer is a polarizing film with a protective layer comprising a photo-alignment polymer. According to claim 2,
The base layer is a polarizing film with a protective layer having a 1/4 wave plate function. According to claim 1,
The polarizing film further has a base layer,
The base layer is a polarizing film with a protective layer having a 1/4 wave plate function. According to claim 1,
The liquid crystal compound is a polarizing film with a protective layer comprising a polymer of a polymerizable liquid crystal compound. According to claim 1,
The visibility correction polarization degree of the first area is 90% or more,
A polarizing film with a protective layer, wherein the visibility correction polarization degree of the second region is 10% or less. According to claim 1,
The visibility corrected single transmittance of the first region is 35% or more,
A polarizing film with a protective layer, wherein the visibility corrected single transmittance of the second region is 80% or more. According to claim 1,
The second region has a circular, oval, oval, or polygonal shape when viewed in plan,
When the second region is circular, the diameter is 5 cm or less,
When the second region is oval or oblong, the major axis is 5 cm or less,
When the second area is a polygon, the diameter of a virtual circle drawn so that the polygon is inscribed is 5 cm or less. According to claim 1,
The first region is a polarizing film with a protective layer that exhibits a Bragg peak in X-ray diffraction measurement. A preparation 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 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 content of the dichroic dye in the part of the polarizing layer is reduced. and a liquid substance contact step of forming a first region containing the dichroic dye and a second region having a content of the dichroic dye less than that of the first region,
The difference between the thickness of the first region and the thickness of the second region is 0.5 μm or less,
More than 10 m in length,
The method for producing a polarizing film, wherein the liquid substance capable of reducing the content of the dichroic dye in the polarizing layer is an acid. According to claim 11,
The liquid contact process is,
A protective layer-forming laminated film is obtained by laminating a protective layer having a covering area for covering the polarizing layer and an exposed area for exposing the polarizing layer on the polarizing layer of the laminated film prepared in the above preparation step. Layer stacking process,
A decolorized laminated film in which the content of a dichroic dye in a partial region of the polarizing layer is reduced by bringing the protective layer-forming laminated film into contact with a liquid substance capable of reducing the content of the dichroic dye in the polarizing layer. A decolorization process to obtain,
A method for producing a polarizing film, comprising a peeling step of peeling the protective layer from the decolorizing laminated film. According to claim 12,
The exposed area in the protective layer has a circular, oval, oval or polygonal shape when viewed in plan,
When the exposed area is circular, the diameter is 5 cm or less,
When the exposed area is oval or oval, the major diameter is 5 cm or less,
When the exposed area is a polygon, the diameter of a virtual circle drawn so that the polygon is inscribed is 5 cm or less. According to claim 11,
The preparation process is,
An orientation layer forming step of forming an orientation layer by coating a composition for forming an orientation layer on one side of the base layer;
Production of a polarizing film having a polarizing layer forming step of forming the polarizing layer by coating a composition for forming a polarizing layer containing the liquid crystal compound and the dichroic dye on the surface of the base layer on the side where the alignment layer is formed. method. According to claim 14,
The composition for forming the alignment layer includes a photo-alignment polymer,
The orientation layer forming step is a method of producing a polarizing film in which the orientation layer is formed by irradiating polarized light to a coating layer for an orientation layer formed by coating the composition for forming an orientation layer. According to claim 14,
The liquid crystal compound is a polymerizable liquid crystal compound,
The polarizing layer forming step is a method of producing a polarizing film, wherein the polarizing layer is formed by irradiating active energy rays to the polarizing layer coating layer formed by coating the composition for forming the polarizing layer. A method for producing a circularly polarizing plate, comprising a polarizing film produced by the method for producing a polarizing film according to any one of claims 11 to 13, and a retardation layer laminating process for laminating a retardation layer having a quarter wave plate function. . According to claim 17,
The polarizing film is a long polarizing film with a length of 10 m or more,
The retardation layer is a long retardation layer with a length of 10 m or more,
The retardation layer stacking process forms a long laminate by laminating the long polarizing film and the long retardation layer,
Additionally, a method for producing a circular polarizing plate, including a cutting process of cutting the long laminate into sheet pieces.