CN111279232A - Manufacturing method of polarizing film and polarizing film - Google Patents

Abstract

The manufacturing method of a polarizing film has the following steps: a preparation step of preparing a laminate film having a polarizing layer containing a dichroic dye on at least one side of a base material layer; a protective layer lamination step of laminating the polarizing layer of the laminate film with A protective layer for covering the covered area of the polarizing layer and the exposed area for exposing the polarizing layer to obtain a laminated film with the protective layer; the solution contacting step, by making the laminated film with the protective layer and the protective layer capable of polarizing light A film with a patterned polarizing layer having a patterned polarizing layer formed by removing a part of a region of the polarizing layer is obtained by contacting the dissolving solution of the dissolved layer; and a peeling step of removing the protective layer from the film with the patterned polarizing layer stripped.

Description

Manufacturing method of polarizing film and polarizing film

technical field

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

Background technique

Compared with liquid crystal display devices, organic EL display devices using organic light-emitting diodes (OLEDs) can not only achieve light weight and thickness reduction, but also achieve high image quality such as a wide viewing angle, fast response speed, and high contrast. Therefore, it has been applied to various fields such as smartphones, televisions, and digital cameras. In an organic EL display device, it is known to use a circularly polarizing plate or the like to improve the antireflection performance in order to suppress deterioration of visibility due to reflection of external light.

As polarizing films that can be used for such circularly polarizing plates, Japanese Patent Laid-Open No. 2015-206852 (Patent Document 1) and Japanese Patent Laid-Open No. 2015-212823 (Patent Document 2) describe laminating warp patterns on a substrate. A patterned polarizing film made of a cured liquid crystal film.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2015-206852

Patent Document 2: Japanese Patent Laid-Open No. 2015-212823

SUMMARY OF THE INVENTION

The problem to be solved by the invention

The objective of this invention is to provide the manufacturing method and the polarizing film of a novel polarizing film which have at least two types of areas which are mutually different in the degree of visibility correction polarization.

means of solving problems

The present invention provides a method for producing a polarizing film and a polarizing film shown below.

[1] The manufacturing method of polarizing film, it has the following steps:

a preparation step of preparing a laminate film having a polarizing layer containing a dichroic dye on at least one side of the base material layer;

In the protective layer lamination step, a protective layer having a covering region for covering the polarizing layer and an exposed region for exposing the polarizing layer is laminated on the polarizing layer of the laminated film, thereby obtaining a protective layer-provided laminated film ;

The dissolving solution contacting step is to obtain a patterned polarizing layer having a patterned polarizing layer formed by removing a part of the polarizing layer by contacting the laminated film with the protective layer with a dissolving solution capable of dissolving the polarizing layer. films of polarizing layers; and

In the peeling step, the protective layer is peeled off from the film with the patterned polarizing layer.

[2] The method for producing a polarizing film according to [1], wherein the preparation step includes the following steps:

an alignment layer forming step of applying a composition for forming an alignment layer to one side of the base material layer to form an alignment layer; and

In the polarizing layer forming step, the polarizing layer is formed by applying a composition for forming a polarizing layer containing a liquid crystal compound and the dichroic dye on the surface of the base material layer on which the alignment layer is formed.

[3] The method for producing a polarizing film according to [2], wherein the composition for forming an alignment layer contains a photo-alignment polymer,

In the said alignment layer formation process, the coating layer for alignment layers formed by apply|coating the said composition for alignment layer formation is irradiated with polarized light, and the said alignment layer is formed.

[4] The method for producing a polarizing film according to [2] or [3], wherein the polarizing layer is a layer in which a polymerizable liquid crystal compound is oriented,

In the polarizing layer forming step, the polarizing layer coating layer formed by applying the polarizing layer forming composition is irradiated with active energy rays to form the polarizing layer.

[5] The method for producing a polarizing film according to any one of [2] to [4], wherein the polarizing layer exhibits a Bragg peak in X-ray diffraction measurement.

[6] The method for producing a polarizing film according to any one of [1] to [5], wherein a plan view shape of the exposed region is a circle, an ellipse, an oval, or a polygon,

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

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

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

[7] The method for producing a polarizing film according to any one of [1] to [6], wherein the length of the polarizing film is 10 m or more.

[8] The method for producing a polarizing film according to any one of [1] to [7], wherein the base material layer has a quarter-wave plate function.

[9] The manufacturing method of a circularly polarizing plate, which has the following steps:

The retardation layer lamination step includes laminating the polarizing film produced by the method for producing a polarizing film according to any one of [1] to [7] and a retardation layer having a quarter-wave plate function.

[10] The method for producing a circularly polarizing plate according to [9], wherein the polarizing film is an elongated polarizing film having a length of 10 m or more,

The aforementioned retardation layer is an elongated retardation layer with a length of 10 m or more,

In the retardation layer lamination step, by laminating the elongated polarizing film and the elongated retardation layer to form an elongated laminate,

The aforementioned manufacturing method further includes a cutting step of cutting the aforementioned elongated laminate into individual pieces.

[11] A polarizing film, which is a polarizing film having a polarizing region and a low-polarizing region, the low-polarizing region having a lower degree of visibility-corrected polarization than the polarizing region,

The above-mentioned polarization region includes a liquid crystal compound and a dichroic dye, and the visibility correction polarization degree is 90% or more,

The aforementioned low polarization region does not contain liquid crystal compounds and dichroic dyes,

The top view shape of the aforementioned low polarization region is a circle, an ellipse, an oval or a polygon,

When the aforementioned low polarization region is circular, the diameter is 5 cm or less,

When the low-polarization region is elliptical or oval, the major axis is 5 cm or less,

When the low-polarization region is a polygon, the diameter of an imaginary circle drawn so as to inscribe the polygon is 5 cm or less.

[12] The polarizing film according to [11], wherein the visibility correction polarization degree of the low polarization region is 10% or less.

[13] The polarizing film according to [11] or [12], wherein the visibility correction monomer transmittance of the polarization region is 35% or more,

The visibility correction single transmittance of the low polarization region is 80% or more.

[14] The polarizing film according to any one of [11] to [13], wherein the length of the polarizing film is 10 m or more.

effect of invention

According to the present invention, it is possible to provide a method for producing a polarizing film having at least two types of regions having different degrees of visibility correction polarization from each other.

Description of drawings

1 is a schematic plan view showing an example of the polarizing film of the present invention.

2 ] (a) to (e) are schematic cross-sectional views showing an example of a layer structure obtained in each step of the manufacturing process of the polarizing film of the present invention.

[ Fig. 3] (a) to (c) are schematic cross-sectional views showing an example of the circularly polarizing plate of the present invention, respectively.

Detailed ways

Hereinafter, the manufacturing method of the polarizing film of this invention, and preferable embodiment of a polarizing film are demonstrated, referring drawings. In addition, the scope of the present invention is not limited to the embodiment described here, and various changes can be made in the range which does not impair the gist of the present invention.

[First Embodiment (Manufacturing Method of Polarizing Film and Polarizing Film)]

FIG. 1 is a schematic plan view showing an example of the polarizing film of the present invention. FIGS. 2( a ) to ( e ) are schematic cross-sectional views showing the layer structure obtained in each step of the manufacturing process of the polarizing film shown in FIG. 1 . FIG. 2(e) is an X-X cross-sectional view of FIG. 1 . The manufacturing method of the polarizing film 1 of this embodiment has the following steps:

The preparation step is to prepare the laminated film 62 having the polarizing layer 11 containing the dichroic dye on at least one side of the base material layer 13 ( FIG. 2( b ));

In the protective layer lamination step, on the polarizing layer 11 of the laminate film 62, a protective layer 35 having a covering region 35a for covering the polarizing layer 11 and an exposed region 35b for exposing the polarizing layer 11 is stacked, thereby obtaining a protective layer 35. layered laminate film 63 (FIG. 2(c));

In the dissolving liquid contacting step, the laminated film 63 with a protective layer is brought into contact with a dissolving liquid capable of dissolving the polarizing layer 11 , thereby obtaining a patterned polarizing layer 11 ′ having a patterned polarizing layer 11 ′ formed by removing a partial region of the polarizing layer 11 . Patterned polarizer film 64 (FIG. 2(d));

In the peeling step, the protective layer 35 is peeled off from the film 64 with the patterned polarizing layer. Thereby, the polarizing film 1 having the patterned polarizing layer 11' as shown in, for example, Figs. 1 and 2(e) can be produced. The polarizing layer 11 may contain a liquid crystal compound, and may be a layer in which a polymerizable liquid crystal compound is aligned.

(polarizing film)

An example of the polarizing film obtained by the above-mentioned manufacturing method is demonstrated. The polarizing film 1 shown in Fig. 1 is a film having a function of light absorption anisotropy, and has a patterned polarizing layer 11'. The patterned polarizing layer 11' has a polarization region 11a and a low polarization region 11b having a lower degree of visibility-corrected polarization (Py) than the polarization region 11a. The polarization region 11a contains a liquid crystal compound and a dichroic dye, and the visibility correction polarization degree is 90% or more. The low polarization region 11b does not contain a liquid crystal compound and a dichroic dye, and is preferably an opening of the patterned polarizing layer 11'. The polarizing film 1 may be a film having the above-described patterned polarizing layer 11' on the base material layer 13.

The polarizing film 1 is a film having a patterned polarizing layer 11', but may have an orientation layer 12, other layers, and the like in addition to the above-described base material layer 13. The alignment layer 12 will be described in detail later. Examples of other layers include a surface protective layer provided for the purpose of protecting the surface of the patterned polarizing layer 11', for example. When the polarizing film 1 has the base material layer 13, it is preferable to provide a surface protective layer on the surface of the patterned polarizing layer 11' on the opposite side to the base material layer 13, and when the base material layer 13 is peeled off and used, A surface protective layer may also be provided on the side of the patterned polarizing layer 11 ′ from which the base material layer 13 is peeled off. 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.

It should be noted that the polarizing film 1 shown in FIG. 2( e ) has an example in which the orientation layer 12 and the patterned polarizing layer 11 ′ are provided on one side of the base material layer 13 , but the base material layer 13 may be Both surfaces of the material layer 13 have an alignment layer and a patterned polarizing layer. The structures of the patterned polarizing layers provided on both sides of the base material layer 13 may be the same or different from each other.

The polarizing film 1 may be an elongated polarizing film having a length of 10 m or more, and in this case, the polarizing film 1 may be formed as a wound body wound in a roll shape. The polarizing film can be continuously drawn out from the roll body, and the steps such as lamination with the retardation layer to be described later, and dicing into individual pieces can be performed. The length of the elongated polarizing film formed as a roll body is not particularly limited, as long as it is 10 m or more, for example, it can be formed to be 10000 m or less.

The polarizing region 11a of the patterned polarizing layer 11' may contain a liquid crystal compound and a dichroic dye. The visibility correction polarization degree (Py) of the polarization region 11a is preferably 90% or more, more preferably 92% or more, still more preferably 95% or more, and usually 100% or less. In addition, it is preferable to set the visibility correction single transmittance (Ty) of the polarization region 11a to, for example, 35% or more, more preferably 40% or more, still more preferably 44% or more, and usually less than 50%.

The low-polarization region 11b of the patterned polarizing layer 11' preferably does not contain liquid crystal compounds and dichroic dyes, preferably has a visibility correction polarization (Py) lower than that of the polarization region 11a, and has a visibility correction monomer transmittance higher than that of the polarization region 11a. Overrate (Ty). The visibility correction polarization degree (Py) of the low polarization region 11b may be, for example, 10% or less, preferably 5% or less, more preferably 1% or less, and may be 0%. In addition, the visibility correction single transmittance (Ty) of the low polarization region 11b can be, 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 individual transmittance (Ty) in this specification can be calculated based on the polarization degree and the individual transmittance measured using a spectrophotometer. For example, in the wavelength range of 380 nm to 780 nm, which is a visible light, using a spectrophotometer equipped with a folder with a polarizer, the two-beam method can be used to measure the transmission axis direction (orientation vertical direction). ) and transmittance (T ₂ ) in the direction of the absorption axis (the same orientation ₎ . For the degree of polarization and the single transmittance in the visible light range, using the following formulas (Equation 1) and (Equation 2), the degree of polarization and the single transmittance at each wavelength were calculated, and further, JIS Z 8701 was used. The 2-degree field of view (C light source) is corrected for visibility, which can be calculated in the form of the visibility-corrected single transmittance (Ty) and the visibility-corrected polarization degree (Py).

Degree of polarization [%]={(T ₁ -T ₂ )/(T ₁ +T ₂ )}×100 (Formula 1)

Monomer transmittance [%]=(T ₁ +T ₂ )/2 (Formula 2)

The occupied area of the polarizing region 11 a and the occupied area of the low-polarization region 11 b may be appropriately selected according to the properties required for the polarizing film 1 . The total ratio of the occupied area of the polarizing region 11a and the low-polarization region 11b with respect to the surface area of the polarizing film 1 is preferably 90% or more, more preferably 95% or more, and further preferably 99% or more. The occupied area of the polarization region 11a is preferably 50% or more, more preferably 70% or more, and even more preferably 80% or more, relative to the total area of the occupied area of the polarization region 11a and the occupied area of the low polarization region 11b. For example, as shown in FIG. 1 , the occupied area of the low polarization region 11b is smaller than that of the polarization region 11a, and the polarization region 11a may be provided so as to surround the low polarization region 11b. In the polarizing film 1 shown in FIG. 1, the polarizing regions 11a are provided so as to surround one circular low-polarization region 11b, but a plurality of the low-polarization regions 11b may be provided independently of each other.

The shape of the polarization region 11a and the shape of the low polarization region 11b are not particularly limited. For example, as shown in FIG. 1, when the polarization region 11a is provided so as to surround the low polarization region 11b, the plan view shape of the low polarization region 11b can be formed as Circles; ovals; ovals; polygons such as triangles, squares, rectangles, and rhombus; character shapes; arbitrary shapes such as their combinations.

The plan view shape of the low polarization region 11b is preferably a circle, an ellipse, an oval, or a polygon. When the low polarization region 11b is circular, the diameter thereof is preferably 5 cm or less, more preferably 3 cm or less, and further preferably 2 cm or less. When the low polarization region 11b is elliptical or oval, the long axis is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the low polarization region 11b is a polygon, the diameter of an imaginary circle drawn so as to inscribe the polygon is preferably 5 cm or less, more preferably 3 cm or less, and still more preferably 2 cm or less. The low-polarization region 11b having the shape described above can be suitably used as a region corresponding to the lens position of a camera provided in a smartphone, a tablet, or the like. By not containing the liquid crystal compound and the dichroic dye in the low-polarization region 11b, since excellent transparency can be obtained, the performance of the camera can be improved.

In addition, the polarizing region 11a and the low-polarization region 11b may be provided so as to have a linear shape, a strip shape, a wave shape, or the like in plan view. In this case, a plurality of polarization regions 11a and low polarization regions 11b may be alternately provided, respectively. In this case, the widths of the polarization region 11a and the low polarization region 11b are each independently preferably 1 μm to 10 mm, more preferably 1 μm to 1 mm, and even more preferably 1 μm to 100 μm.

It should be noted that, when the polarizing film is a long polarizing film, the long polarizing film can usually be cut into a predetermined size according to the use of the polarizing film. The arrangement of the polarization regions and the low polarization regions in the elongated polarizing film is set so that the polarization regions 11a and the low polarization regions 11b are formed at predetermined positions. For example, when the polarizing film after cutting is the polarizing film 1 shown in FIG. 1 , it is preferable to provide a plurality of low-polarization regions 11 b at predetermined intervals in the longitudinal direction and/or the width direction of the long polarizing film. .

The thickness of the polarizing region 11a of the patterned polarizing layer 11' is preferably 0.5 µm or more, more preferably 1 µm or more, and preferably 5 µm or less, more preferably 3 µm or less. In addition, the thickness of the low polarization region 11b is preferably less than 0.5 μm, and more preferably 0 m. The thickness of the polarization region 11a and the low polarization region 11b can be measured with an interference film thickness meter, a laser microscope, a stylus type film thickness meter, or the like.

Next, each process of the manufacturing method of the polarizing film 1 is demonstrated based on FIG.2(a)-(e).

(preparation process)

The laminated film 62 prepared in the preparation process is not particularly limited, as long as it is a laminated film having the polarizing layer 11 on at least one side of the base material layer 13 , and as shown in FIG. 2( b ), it is preferably on the base material layer 13 A laminated film formed by laminating the alignment layer 12 and the polarizing layer 11 in this order. Such a laminated film 62 can be produced through the following steps: an alignment layer forming step in which the composition for forming an alignment layer is applied to one surface of the base material layer 13 to form the alignment layer 12 to obtain a base material layer with an alignment layer 61 ( FIG. 2( a )); and a polarizing layer forming step of applying a composition for forming a polarizing layer on the surface of the base material layer 61 with an alignment layer on the side where the alignment layer 12 is formed to form a polarized light Layer 11.

(substrate layer)

The base material layer 13 can be used to support the alignment layer 12 and the polarizing layer 11 when manufacturing the polarizing film 1, and can also be used to support the patterned polarizing layer 11' of the polarizing film 1.

The base material layer 13 may be a glass base material or a resin base material, preferably a resin base material. In addition, it is more preferable that the base material layer 13 is obtained by unwinding the long resin base material wound in a roll shape from the viewpoint of being able to continuously manufacture the polarizing film 1 . The resin base material is preferably a base material having translucency that allows visible light to pass therethrough. The light transmittance as used herein means that the transmittance of the visibility correction alone is 80% or more with respect to light in the wavelength range of 380 to 780 nm.

The thickness of the base material layer 13 is preferably as thin as possible from the quality point of view to enable practical handling, but if it is too thin, the strength decreases and the workability tends to be poor. The thickness of the base material layer 13 is usually 5 μm to 300 μm, preferably 20 μm to 200 μm. In addition, the base material layer 13 may be provided in a releasable manner. For example, after bonding the patterned polarizing layer 11 ′ of the polarizing film 1 to a member to be a display device, a retardation layer to be described later, etc., it can be removed from the polarized light. Film 1 peels off the substrate layer. Thereby, the further thinning effect of the polarizing film 1 can be acquired.

Examples of resins constituting the resin substrate include polyolefins such as polyethylene and polypropylene; cyclic olefin-based resins such as norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; acrylic acid ester; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone ; polyether ketone; polyphenylene sulfide and polyphenylene ether; and so on.

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

Commercially available cyclic olefin-based resins include "Topas" (registered trademark) (manufactured by Ticona Corporation (Germany)), "ARTON" (registered trademark) (manufactured by JSR Corporation), "ZEONOR (ゼオノア)" ( registered trademark), "ZEONEX (ゼオ礻ツクス)" (registered trademark) (the above are manufactured by ZEON Co., Ltd.), and "APEL" (registered trademark) (manufactured by Mitsui Chemicals Co., Ltd.). Such a cyclic olefin-based resin can be formed into a film by known means such as a solvent casting method and a melt extrusion method, and can be used as a resin substrate. A commercially available resin base material of a cyclic olefin-based resin can also be used. Examples of resin substrates of commercially available cyclic olefin-based resins include "ESCENA" (registered trademark), "SCA40" (registered trademark) (the above are manufactured by Sekisui Chemical Industry Co., Ltd.), and "ZEONOR FILM" (registered trademark). trademark) (manufactured by OPTES Co., Ltd.) and "ARTON Film" (registered trademark) (manufactured by JSR Corporation).

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

In addition, the base material layer 13 may have the function of a quarter wave plate. By making the base material layer 13 function as a quarter-wave plate, a polarizing film having the function of a circular polarizer can be obtained by combining the base material layer 13 and the patterned polarizing layer 11'. Thereby, a circularly polarizing plate can be obtained even if the retardation layer which has the function of a quarter wave plate other than the base material layer 13 is not bonded to the polarizing film 1 . In addition, when the base material layer 13 has a multilayer structure, the patterned polarizing layer 11 ′ can be formed by using a product obtained by laminating a layer having a half-wave plate function and a layer having a quarter-wave plate function. A circularly polarizing plate was obtained by stacking on the layer side having the function of a 1/2 wavelength plate. Alternatively, when the base material layer 13 has a multi-layer structure, it is also possible to obtain a circular shape by using a product in which a layer having a reverse wavelength dispersion function of a quarter-wave plate and a layer having a positive C plate function are laminated. polarizer.

(polarizing layer)

The polarizing layer 11 is not particularly limited as long as it contains a dichroic dye, and preferably has a region containing a liquid crystal compound and a dichroic dye. When the polarizing layer 11 has the polarization characteristic 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 . In addition, when the polarizing layer 11 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 .

In the polarizing layer 11, in the region where the dichroic dye and the liquid crystal compound are horizontally aligned with respect to the surface of the polarizing film 1, the absorbance A1 (λ) in the horizontal direction of the liquid crystal alignment with respect to light with a wavelength of λnm is related to the liquid crystal alignment. The ratio of the absorbance A2(λ) in the in-plane vertical direction, that is, the dichroic ratio (=A1(λ)/A2(λ)) is preferably 7 or more, more preferably 20 or more, and further preferably 30 or more. The higher the value is, the more polarized light has excellent absorption selectivity. Although it also depends on the kind of dichroic dye, when the polarizing layer 11 is a nematic liquid crystal phase, the said ratio is about 5-10. In addition, when the polarizing layer 11 is a nematic liquid crystal phase and a smectic liquid crystal phase, the liquid crystal compound and the dichroism can be confirmed by, for example, surface observation by various microscopes and scattering degree measurement by a haze meter. Sex pigments did not phase separate.

The thickness of the polarizing layer 11 is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 10 μm or less, and more preferably 5 μm or less. The thickness of the polarizing layer 11 can be measured with an interference film thickness meter, a laser microscope, a stylus type film thickness meter, or the like.

(Orientation layer forming step)

In the alignment layer forming step, the alignment layer forming composition is applied to one surface of the base material layer 13 to form the alignment layer 12, thereby obtaining the base material layer 61 with the alignment layer ( FIG. 2( a )). The alignment layer 12 formed in the alignment layer forming step may have an alignment regulating force for aligning the liquid crystal compound laminated thereon with liquid crystal alignment in a desired direction. As the composition for forming an alignment layer, an alignment polymer composition, a composition for forming a photo-alignment film, a composition containing a resin material for forming a trench alignment film, and the like, which will be described later, can be used.

The alignment layer 12 facilitates the 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 the combination thereof can be arbitrarily selected. For example, if the alignment layer 12 is a material that exhibits horizontal alignment as an alignment limiting force, the liquid crystal compound may form a horizontal alignment or a mixed alignment, and if the alignment layer 12 is a material that exhibits a vertical alignment, the liquid crystal compound may form a vertical alignment or a tilt orientation. Expressions such as horizontal and vertical indicate the direction of the long axis of the aligned liquid crystal compound when the plane of the polarizing film 1 is used as a reference. For example, the vertical alignment refers to having the long axis of the polymerizable liquid crystal aligned in the direction perpendicular to the plane of the polarizing film 1 . The term "perpendicular" here means 90°±20° with respect to the plane of the polarizing film 1 . The polarizing film 1 preferably has the polarization characteristics of the plane of the polarizing film 1 , and therefore, the alignment layer 12 is preferably formed of a material that exhibits horizontal alignment.

The alignment control force of the alignment layer 12 can be arbitrarily adjusted according to the surface state and rubbing conditions when the alignment layer 12 is formed of an alignment polymer, and can be irradiated with polarized light when the alignment layer 12 is formed of a photo-alignment polymer. Conditions, etc. can be adjusted arbitrarily. In addition, the liquid crystal orientation can also be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

The thickness of the alignment layer 12 is usually 10 nm to 5000 nm, preferably 10 nm to 1000 nm, and more preferably 30 nm to 300 nm. In addition, it is preferable that the alignment layer 12 formed between the base material layer 13 and the polarizing layer 11 be insoluble in the solvent used for forming the polarizing layer 11 on the alignment layer 12 and have a solvent for removing, Heat resistance in heat treatment for aligning liquid crystals.

As the alignment layer 12, an alignment film formed of an alignment polymer, a photo alignment film, a groove alignment film, or the like can be mentioned. When the base material layer 13 is a product obtained by unwinding a roll formed by winding an elongated resin base material, the orientation layer 12 is preferably in the point that the orientation direction can be easily controlled. For the photo-alignment film.

Examples of the oriented polymer include polyamides having an amide bond in the molecule, gelatins, polyimides having an imide bond in the molecule, and polyamic acid, polyvinyl alcohol, and alkanes which are hydrolyzates thereof. base-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, or polyacrylate, etc. Among them, polyvinyl alcohol is preferable. These oriented polymers may be used alone or in combination of two or more.

The alignment film formed of the alignment polymer can usually be obtained by applying a composition obtained by dissolving the alignment polymer in a solvent (hereinafter, sometimes referred to as "the alignment polymer composition".) on the For the base material layer 13, the solvent is removed; alternatively, the oriented polymer composition is applied to the base material layer 13, the solvent is removed, and rubbing (rubbing method) is performed.

Examples of solvents that can be used in the oriented polymer composition include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, methyl cellosolve, butyl cellosolve, and 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; acetone, methyl ethyl ketone, cyclopentanone , ketone solvents such as 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; and the like. These solvents may be used alone or in combination of two or more.

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

As the alignment polymer composition, a commercially available alignment film material can be used as it is. As a commercially available alignment film material, SUNEVER (registered trademark) (manufactured by Nissan Chemical Industries, Ltd.), OPTMER (registered trademark) (manufactured by JSR Corporation), etc. are mentioned.

Examples of a method for applying the oriented polymer composition to the base material layer 13 include coating methods such as spin coating, extrusion, gravure coating, die coating, bar coating, and applicator methods. , a known method such as a printing method such as a flexographic method. When the polarizing film 1 is produced by a roll-to-roll continuous production method, a printing method such as a gravure coating method, a die coating method, or a flexographic method can be used as the coating method.

By removing the solvent contained in the oriented polymer composition, a dry film of the oriented polymer can be formed. As a solvent removal method, a natural drying method, a ventilation drying method, a heating drying method, a vacuum drying method, etc. are mentioned. Then, the above-mentioned dry film is brought into contact with a rotating rubbing roll on which a rubbing cloth is wound, whereby the alignment layer 12 can be formed.

The photo-alignment film can usually be applied to the base material layer 13 by applying a composition (hereinafter, sometimes referred to as "photo-alignment film-forming composition") containing a polymer or monomer having a photoreactive group and a solvent. The coating layer for alignment layers thus formed is obtained by irradiating polarized light (preferably polarized UV light). The photo-alignment film is more preferable because the direction of the alignment-regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

The photoreactive group refers to a group that generates liquid crystal alignment ability by irradiating light. Specifically, it refers to a photoreaction that can cause alignment induction of molecules or an isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction, which is caused by irradiation with light, which is the origin of the liquid crystal alignment ability. group. Among the above-mentioned photoreactive groups, a group capable of undergoing a dimerization reaction or a photocrosslinking reaction is preferable because of its excellent orientation. The photoreactive group capable of causing the above-mentioned reaction is preferably a photoreactive group having an unsaturated bond, especially a double bond, and more preferably a photoreactive group selected from a carbon-carbon double bond (C=C bond), a carbon- A group of at least one selected from the group consisting of a nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond).

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyalkenyl group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, or a cinnamon group. Acyl, etc. The chalcone group or the cinnamoyl group is preferable from the viewpoint of easy control of the reactivity and the development of the alignment control force during photo-alignment. As a photoreactive group which has a C=N bond, the group which has structures, such as an aromatic Schiff base and an aromatic hydrazone, is mentioned. Examples of the photoreactive group having an N=N bond include an azophenyl group, an azonaphthyl group, an aromatic heterocyclic azo group, a disazo group, a formazan group, and the like, and azobenzene oxide is used as the basic structure of the group. As a photoreactive group which has a C=O bond, a benzophenone group, a coumarin group, an anthraquinone group, a maleimide group, etc. are mentioned. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group or a haloalkyl group.

As the solvent of the composition for forming a photo-alignment film, a solvent in which a polymer and a monomer having a photoreactive group are dissolved is preferable, and as the solvent, for example, the above-mentioned solvent for the alignment polymer composition is exemplified. solvent, etc.

The content of the photo-reactive group-containing polymer or monomer in the photo-alignment film-forming composition may be appropriate depending on the type of the photo-reactive group-containing polymer or monomer, and the thickness of the photo-alignment film to be produced The adjustment is preferably 0.2 mass % or more, particularly preferably in the range of 0.3 to 10 mass %. In addition, a polymer material such as polyvinyl alcohol and polyimide, and a photosensitizer may be contained within a range that does not significantly impair the properties of the photo-alignment film.

As a method of apply|coating the composition for photo-alignment film formation to the base material layer 13, the method similar to the method of apply|coating the above-mentioned orientation polymer composition to the base material layer 13 is mentioned. As a method of removing a solvent from the applied composition for photo-alignment film formation, the same method as the method of removing a solvent from an alignment polymer composition is mentioned, for example.

Irradiation with polarized light may be performed directly on the dry film after removing the solvent from the composition for forming a photo-alignment film applied on the base material layer 13, or may be performed by irradiating the dry film with polarized light transmitted through the base material layer 13. The method is carried out from the base material layer 13 side. In addition, 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 a wavelength in a wavelength region in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferable. Examples of the light source for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF, and more preferred are high-pressure mercury lamps, ultra-high pressure mercury lamps, or metal halide lamps. These lamps are preferable because the luminous intensity of ultraviolet light having a wavelength of 313 nm is large. Polarized light can be irradiated by irradiating light from a light source through an appropriate polarizer. As the polarizer, polarizing filters, polarizing prisms such as Glan-Thompson and Glan-Taylor, and wire grid polarizers can be used.

In addition, when performing rubbing and polarized light irradiation, if masking (masking) is performed, the several area|region (pattern) which differs in the direction of liquid crystal orientation can also be formed.

The groove alignment film is a film having a concavo-convex 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 aligned in a direction along the grooves.

As a method of obtaining a trench alignment film, after exposing the surface of the photosensitive polyimide film through an exposure mask having a slit in a pattern, developing and rinsing to form A method of concave-convex pattern; a method of forming a layer of UV curable resin before curing on a plate-shaped original plate having grooves on the surface, and a method of moving the resin layer to a base material and then curing it; pushing a roll-shaped original plate having a plurality of grooves against A method of forming unevenness to a film of a UV-curable resin before curing formed on a substrate, and then curing it; and the like. Specifically, the method described in Japanese Patent Application Laid-Open No. 6-34976 and Japanese Patent Application Laid-Open No. 2011-242743 can be mentioned.

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

(Polarizing layer forming step)

In the polarizing layer forming step, the polarizing layer forming composition is applied to the surface of the base material layer 61 with an alignment layer on the side where the alignment layer 12 is formed, thereby forming the polarizing layer 11 . The polarizing layer-forming composition is a composition containing a liquid crystal compound and a dichroic dye, and preferably contains a solvent and a polymerization initiator, but may also contain a sensitizer, a polymerization inhibitor, a leveling agent, a reactive additive, and the like.

(Liquid Crystal Compound)

As the liquid crystal compound contained in the composition for forming a polarizing layer, a known liquid crystal compound can be used. The type of the liquid crystal compound is not particularly limited, and rod-like liquid crystal compounds, discotic liquid crystal compounds, and mixtures thereof can be used. In addition, the liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof.

As the liquid crystal compound, a polymerizable liquid crystal compound is preferably used. By using the polymerizable liquid crystal compound, the hue of the polarizing film can be arbitrarily controlled, and the polarizing film can be greatly reduced in thickness. Moreover, since a polarizing film can be manufactured without performing a stretching process, it can be set as a non-stretchable polarizing film which does not have stretching relaxation by heat.

The polymerizable liquid crystal compound refers to a compound having a polymerizable group and having liquid crystallinity. The polymerizable group refers to a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. The photopolymerizable group as used herein refers to a group that can participate in a polymerization reaction by an active radical, an acid, or the like generated from a photopolymerization initiator described later. Examples of the polymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, and oxirane base, oxetanyl, etc. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxetanyl group, and an oxetanyl group are preferable, and an acryloxy group is more preferable. The liquid crystallinity may be either a thermotropic liquid crystal or a lyotropic liquid crystal, and when mixed with a dichroic dye as in the polarizing layer 11 of the present embodiment, a thermotropic liquid crystal is preferably used.

的膜。对于本实施方式的偏光膜1而言，通过使偏光层11包含聚合性液晶化合物以近晶相的状态聚合而成的聚合物，从而能向偏光层11赋予较高的偏光特性，因而优选。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. The liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and more preferably a high-order smectic phase from the viewpoint of improving performance. Among them, it is more preferable to form smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, and smectic K phase Or a higher-order smectic liquid crystal compound of a smectic L phase, more preferably a higher-order smectic liquid crystal compound that forms a smectic B phase, a smectic F phase, or a smectic I phase. When the polarizing layer 11 formed of the polymerizable liquid crystal compound is in these high-order smectic phases, a region with high polarization performance can be formed in the polarizing layer 11 . In addition, in the region with high polarization performance as described above, Bragg peaks derived from higher-order structures such as a hexagonal phase and a crystal phase can be obtained in X-ray diffraction measurement. The Bragg peak is a peak due to the periodic structure of molecular orientation, and its periodic interval can be obtained as

film. In the polarizing film 1 of the present embodiment, it is preferable that the polarizing layer 11 contains a polymer in which a polymerizable liquid crystal compound is polymerized in a smectic phase, since high polarization characteristics can be imparted to the polarizing layer 11 .

Whether or not the polymerizable liquid crystal compound exhibits a nematic liquid crystal phase and a smectic liquid crystal phase can be confirmed, for example, as follows. The composition for forming a polarizing film is coated on a base material to form a coating film, and then the solvent contained in the coating film is removed by heat treatment under conditions where the polymerizable liquid crystal compound does not polymerize. Next, the coating film formed on the base material is heated to the isotropic phase temperature, cooled gradually, and the liquid crystal phase thus developed is subjected to texture observation with a polarizing microscope, X-ray diffraction measurement, or differential scanning measurement. Thermal assay to check.

As such a polymerizable liquid crystal compound, the compound represented by following formula (A) (it may be called a compound (A) hereafter) etc. are mentioned specifically,.

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, and here, the divalent aromatic group or divalent The hydrogen atom contained in the alicyclic hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group. group or nitro group, and the carbon atom constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be replaced by an oxygen atom, a sulfur atom or a nitrogen atom. However, at least one of X ¹ , X ² and X ³ is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group.

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

V ¹ and V ² independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and -CH ₂ - constituting the alkanediyl group may be substituted with -O-, -S- or NH- .

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

In the compound (A), at least one of X ¹ , X ² and X ³ is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group. In particular, X ¹ and X ³ are preferably cyclohexane-1,4-diyl which may have a substituent, and the cyclohexane-1,4-diyl is more preferably trans-cyclohexane-1,4 - Two bases. In the case of a structure including a trans-cyclohexane-1,4-diyl group, there is a tendency that smectic liquid crystallinity is easily exhibited. In addition, as a substituent which the optionally substituted 1,4-phenylene group and the optionally substituted cyclohexane-1,4-diyl group may have, a methyl group, an ethyl group, or a butyl group can be mentioned. A halogen atom such as an alkyl group having 1 to 4 carbon atoms, a cyano group, a chlorine atom or a fluorine atom. Unsubstituted is preferred.

Y ¹ and Y ² independently of each other are preferably a single bond, -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCO-, -N=N-, -CR ^a =CR ^b -, -C ≡C- or CR ^a =N-, and R ^a and R ^b independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. When 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 do not contain cyclohexane-1,4-diyl , more preferably Y ¹ and Y ² are mutually different binding forms. In the case of a bonding form in which Y ¹ and Y ² are mutually different, there is a tendency that smectic liquid crystallinity is likely to be exhibited.

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

Examples of the alkanediyl group having 1 to 20 carbon atoms represented by V ¹ and V ² include methylene, ethylene, propane-1,3-diyl, butane-1,3-diyl, Butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, Decane-1,10-diyl, tetradecane-1,14-diyl or eicosane-1,20-diyl, etc. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, and more preferably linear alkanediyl groups having 6 to 12 carbon atoms. When it becomes a linear alkanediyl group having 6 to 12 carbon atoms, the crystallinity is improved, and the smectic liquid crystallinity tends to be easily exhibited.

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

Both U ¹ and U ² are preferably polymerizable groups, and more preferably both are photopolymerizable groups. The polymerizable liquid crystal compound having a photopolymerizable group can be polymerized at low temperature compared with the case of the thermally polymerizable group, and therefore, the polymer of the polymerizable liquid crystal compound can be formed in a state with a high degree of order. Aspects are favorable.

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, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, and oxirane base, oxetanyl, etc. Among them, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxetanyl group or an oxetanyl group is preferable, and a methacryloyloxy group or an acryloyloxy group is more preferable.

As such a polymerizable liquid crystal compound, the following compounds are mentioned, for example.

Among the aforementioned compounds exemplified, those selected from the group consisting of formula (1-2), formula (1-3), formula (1-4), formula (1-6), formula (1-7), formula (1-8) are preferred. ), at least one kind selected from the group consisting of compounds represented by formula (1-13), formula (1-14) and formula (1-15).

The exemplified compound (A) may be used for the polarizing layer 11 alone or in combination. Moreover, when combining 2 or more types of polymerizable liquid crystal compounds, it is preferable that at least 1 type is a compound (A), and it is more preferable that 2 or more types are a compound (A). By combining two or more types of polymerizable liquid crystal compounds, liquid crystallinity may be temporarily maintained even at a temperature equal to or lower than the liquid crystal-crystal phase transition temperature. The mixing ratio in the case of 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.

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

The content of the polymerizable liquid crystal compound in the polarizing layer 11 is usually 50 to 99.5 parts by mass, preferably 60 to 99 parts by mass, and more preferably 70 to 98 parts by mass, relative to 100 parts by mass of the solid content of the polarizing layer 11 , More preferably, it is 80-97 mass parts. When the content of the polymerizable liquid crystal compound is within the above range, the orientation tends to be improved. Here, the solid content refers to the total amount of the components remaining after removing the solvent from the composition for forming a polarizing layer to be described later.

(Dichroic Pigment)

The dichroic dye refers to a dye having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. A dichroic dye is a dye that is aligned together with a liquid crystal compound and exhibits dichroism, and the dichroic dye itself may have polymerizability or liquid crystallinity. The dichroic dye preferably has a property of absorbing visible light, and more preferably has an absorption maximum wavelength (λ _MAX ) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, among which azo dyes are preferred. The azo dyes include monoazo dyes, disazo dyes, trisazo dyes, tetrazo dyes, stilbene azo dyes, and the like, and disazo dyes or trisazo dyes are preferred. The dichroic dyes may be used alone or in combination of two or more. In order to obtain absorption in the entire visible light region, three or more dichroic dyes are preferably combined, and three or more azo dyes are more preferably combined.

Examples of the azo dye include compounds represented by formula (I) (hereinafter, also referred to as "compound (I)" in some cases).

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

[In formula (I), A ¹ , A ² and A ³ independently represent an optionally substituted 1,4-phenylene group, naphthalene-1,4-diyl group, or an optionally substituted divalent In the heterocyclic group, T ¹ and T ² are independently an electron withdrawing group or an electron donating group, and exist at a position of substantially 180° with respect to the in-plane of the azo bond. p represents an integer of 0-4. When p is 2 or more, each A ² may be the same or different from each other. The -N=N- bond may be replaced by a -C=C-, -COO-, -NHCO- or -N=CH- bond in the range where absorption in the visible region is exhibited. ]

Examples of substituents that the 1,4-phenylene group, naphthalene-1,4-diyl group, and divalent heterocyclic group in A ¹ , A ² and A ³ may have include a methyl group and an ethyl group. or alkyl groups with 1 to 4 carbon atoms such as butyl; alkoxy groups with 1 to 4 carbon atoms such as methoxy, ethoxy or butoxy; and 1 to 4 carbon atoms such as trifluoromethyl Fluoroalkyl group of 4; cyano group; nitro group; halogen atom such as chlorine atom and fluorine atom; substituted or unsubstituted amino group such as amino group, diethylamino group and pyrrolidinyl group An amino group of an alkyl group having 1 to 6 carbon atoms, or an amino group of an alkanediyl group having 2 to 8 carbon atoms formed by bonding two substituted alkyl groups to each other. An unsubstituted amino group is -NH ₂ ). In addition, a methyl group, an ethyl group, a hexyl group, etc. are mentioned as a C1-C6 alkyl group. Examples of the alkanediyl group having 2 to 8 carbon atoms include ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, and pentane. Alkane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, or octane-1,8-diyl and the like. In order to include the compound (I) in a highly ordered liquid crystal structure such as a smectic liquid crystal, A ¹ , A ² and A ³ independently of each other are preferably 1,4- A phenylene group or a divalent heterocyclic group, p is preferably 0 or 1. Among them, it is more preferable that p is 1 and at least two of the three structures of A ¹ , A ² and A ³ be 1,4- phenylene.

The divalent heterocyclic group includes a group obtained by removing two hydrogen atoms from quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. When A ² is a divalent heterocyclic group, a structure in which the molecular bond angle is substantially 180° is preferable, and specifically, a benzothiazole, benzimidazole, benzene obtained by condensing two five-membered rings is more preferable. and oxazole structure.

T ¹ and T ² are independently electron-withdrawing groups or electron-donating groups, preferably different structures from each other, more preferably T ¹ is an electron-withdrawing group and T ² is an electron-donating group, or T ¹ is an electron-donating group electron group and T ² is an electron withdrawing group. Specifically, T ¹ and T ² are preferably independently of each other an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a group having one or two carbon atoms An amino group of an alkyl group having 1 to 6 atoms, or an amino group of an alkanediyl group having 2 to 8 carbon atoms formed by two substituted alkyl groups bonded to each other, or a trifluoromethyl group, wherein, in order to be included in the near In a highly ordered liquid crystal structure such as a crystalline liquid crystal, a structure with a small steric hindrance of the molecule is required. Therefore, an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms are preferred. , a cyano group, an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or an amino group wherein two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms.

As such an azo dye, the following are mentioned, for example.

[In formulae (2-1) to (2-6), B ¹ to B ²⁰ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, A cyano group, a nitro group, a substituted or unsubstituted amino group (the definitions of substituted amino group and unsubstituted amino group are as described above), a chlorine atom or a trifluoromethyl group. In addition, from the viewpoint of obtaining high polarization performance, B ² , B ⁶ , B ⁹ , B ¹⁴ , B ¹⁸ , and B ¹⁹ are preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

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, respectively.

When n2 is ² or more, the plurality of B6 may be the same or different, respectively,

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

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

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

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

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

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

[In formula (2-8), R ⁹ to R ¹⁵ 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 said acridine dye, the compound represented by Formula (2-9) is preferable.

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

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

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

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

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

n5 represents an integer of 1-3. ]

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

n6 represents an integer of 1-3. ]

From the viewpoint of obtaining favorable light absorption characteristics, the content of the dichroic dye (in the case of multiple types, the total amount thereof) with respect to 100 parts by mass of the polymerizable liquid crystal compound in the polarizing layer 11 is usually preferably 0.1-30 mass parts, More preferably, it is 1-20 mass parts, More preferably, it is 3-15 mass parts. When the content of the dichroic dye is less than the above range, light absorption becomes insufficient and sufficient polarization performance cannot be obtained, and when the content exceeds the above range, the alignment of liquid crystal molecules may be hindered.

(solvent)

The composition for forming a polarizing layer may contain a solvent. Generally, since a polymerizable liquid crystal compound has a high viscosity, when a polymerizable liquid crystal compound is used as the liquid crystal compound, application of the composition for forming a polarizing layer containing a solvent becomes easy, and as a result, it becomes easy to apply The polarizing layer 11 is formed. The solvent is preferably a solvent that can completely dissolve the polymerizable liquid crystal compound and the dichroic dye, and is preferably a solvent inert to the polymerization reaction of the polymerizable liquid crystal compound.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and the like. , ethylene glycol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate or ethyl lactate and other ester solvents; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2- Ketone solvents such as 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; tetrahydrofuran or dimethoxyethane Isoether solvents; chlorine-containing solvents such as chloroform or chlorobenzene; amides such as dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone solvent, etc. These solvents may be used alone or in combination of two or more.

It is preferable that content of the solvent contained in the composition for polarizing layer formation is 50-98 mass % with respect to the total amount of the composition for polarizing layer formation. In other words, the content of the solid content in the composition for forming a polarizing layer is preferably 2 to 50% by mass. When the content of the solid content is 50 mass % or less, the viscosity of the composition for forming a polarizing layer becomes low, so the thickness of the polarizing layer 11 becomes substantially uniform, and unevenness tends to be less likely to occur in the polarizing layer 11 . In addition, the content of the solid content can be determined in consideration of the thickness of the polarizing layer 11 to be produced.

(polymerization initiator)

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

As a polymerization initiator, a benzoin compound, a benzophenone compound, an alkylphenone compound, an acylphosphine oxide compound, a triazine compound, an iodonium salt, or a sulfonium salt etc. are mentioned, for example.

As a benzoin compound, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, etc. are mentioned, for example.

Examples of the benzophenone compound include benzophenone, methyl phthaloylbenzoate, 4-phenylbenzophenone, and 4-benzoyl-4′-methyldiphenylsulfide , 3,3',4,4'-tetra(tert-butylperoxycarbonyl) benzophenone and 2,4,6-trimethylbenzophenone, etc.

Examples of the alkylphenone compound include diethoxyacetophenone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2- Benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2 -Diphenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one , 1-hydroxycyclohexyl phenyl ketone or oligomer of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one, etc.

As the acylphosphine oxide compound, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc. are mentioned.

Examples of the triazine compound include 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl) Methyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)- 1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)vinyl]-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)vinyl]-1,3,5-triazine or 2,4-bis(trichloromethyl)-6-[2-( 3,4-dimethoxyphenyl)vinyl]-1,3,5-triazine and the like.

As the polymerization initiator, a commercially available polymerization initiator can also be used. Examples of commercially available polymerization initiators include Irgacure (Ilgacure) (registered trademark) 907, 184, 651, 819, 250, 369, 379, 127, 754, OXE01, OXE02, or OXE03 (Ciba Specialty Chemicals, Inc. manufactured by SEIKUOL (registered trademark) BZ, Z, or BEE (manufactured by Seiko Chemical Co., Ltd.); kayacure (Kayacure) (registered trademark) BP100, or UVI-6992 (manufactured by DOW Chemical Company); ADEKA OPTOMER SP-152, N -1717, N-1919, SP-170, ADEKA ARKLSNCI-831, ADEKA ARKLS NCI-930 (made by ADEKA Co., Ltd.); TAZ-A, or TAZ-PP (made by Japan Siber Hegner Co., Ltd.); TAZ-104 (Sanwa Chemical Co., Ltd.); and the like. As the polymerization initiator in the composition for forming a polarizing layer, one kind may be used, or two or more kinds of plural kinds of polymerization initiators may be mixed and used depending on the light source of light.

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

(sensitizer)

The composition for forming a polarizing layer may contain a sensitizer. The sensitizer 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 and alkane-containing Anthracene compounds such as oxyanthracene (for example, dibutoxyanthracene, etc.); phenothiazine or rubrene, etc.

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 accelerated. 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 even more preferably 0.5 to 3 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal compound content.

(Polymerization inhibitor)

From the viewpoint of stably progressing the polymerization reaction, the composition for forming a polarizing layer may contain a polymerization inhibitor. The polymerization inhibitor can be suitably used when a polymerizable liquid crystal compound is used as the liquid crystal compound, and the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

Examples of the polymerization inhibitor include hydroquinone, alkoxy-containing hydroquinone, alkoxy-containing catechol (for example, butylcatechol, etc.), pyrogallol, 2, Free radical scavengers such as 2,6,6-tetramethylpiperidine-1-oxyl radical; thiophenols; β-naphthylamines or β-naphthols, etc.

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, with respect to 100 parts by mass of the content of the polymerizable liquid crystal compound, More preferably, it is 0.5 to 3 parts by mass. When content of a polymerization inhibitor is in the said range, superposition|polymerization can be performed without disturbing the orientation of a polymerizable liquid crystal compound.

(leveling agent)

The composition for forming a polarizing layer may contain a leveling agent. The term "leveling agent" refers to an additive having a function of adjusting the fluidity of the composition and making the film obtained by coating the composition flatter, and examples thereof include organo-modified silicone oil-based, polyacrylate-based, or perfluoroalkyl groups. system leveling agent. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all of the above are manufactured by Dow Corning Toray Co., Ltd.), KP321, KP323, KP324, KP326 , KP340, KP341, X22-161A, KF6001 (all of the above are manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all of the above are Momentive Performance Materials Japan LLC), fluorinert (フロリナ一ト) (registered trademark) FC-72, fluorinert FC-40, fluorinert FC-43, fluorinert FC-3283 (all of which are manufactured by Sumitomo 3M Co., Ltd.), MEGAFACE (registered trademark) R -08, MEGAFACE R-30, MEGAFACE R-90, MEGAFACE F-410, MEGAFACE F-411, MEGAFACE F-443, MEGAFACE F-445, MEGAFACE F-470, MEGAFACE F-477, MEGAFACE F-479, MEGAFACE F -482, MEGAFACE F-483 (all of the above are manufactured by DIC Co., Ltd.), EFTOP (trade name) EF301, EFTOP EF303, EFTOP EF351, EFTOP EF352 (all of the above are manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Surflon ( Registered trademark) S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-105, KH-40, SA-100 (all of the above are AGC Seimi Chemical Co., Ltd. manufactured by . Wait. Among them, a polyacrylate-based leveling agent or a perfluoroalkyl-based leveling agent is preferable.

When the composition for forming a polarizing layer contains a leveling agent, it is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the liquid crystal compound. When the content of the leveling agent is within the above range, the liquid crystal compound tends to be easily aligned horizontally, and the resulting polarizing layer tends to be smoother. When the content of the leveling agent with respect to the liquid crystal compound exceeds the above range, unevenness tends to easily occur in the polarizing layer obtained. In addition, the composition for polarizing layer formation may contain 2 or more types of leveling agents.

(reactive additive)

The composition for forming a polarizing layer may contain reactive additives. As the reactive additive, an additive having a carbon-carbon unsaturated bond and an active hydrogen reactive group in its molecule is preferable. In addition, the "active hydrogen-reactive group" here refers to a group having active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH ₂ ), etc. having a reaction The glycidyl group, the oxazoline group, the carbodiimide group, the aziridine group, the imide group, the isocyanate group, the isothiocyanate group, the maleic anhydride group, etc. are representative examples. The number of carbon-carbon unsaturated bonds or active hydrogen reactive groups that the reactive additive has is usually 1 to 20, and preferably 1 to 10, respectively.

In the reactive additive, at least two active hydrogen-reactive groups are preferably present, and in this case, the active hydrogen-reactive groups present in a plurality 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, preferably a carbon-carbon double bond. Among these, as a reactive additive, it is preferable to contain a carbon-carbon unsaturated bond in the form of a vinyl group and/or a (meth)acryl group ((meth)acryl group). Further, the active hydrogen reactive group is preferably a reactive additive having at least one selected from the group consisting of an epoxy group, a glycidyl group, and an isocyanate group, and a reactive additive having an acrylic group and an isocyanate group is more preferable.

Specific examples of the reactive additives include compounds having a (meth)acrylic group and an epoxy group, such as methacryloyloxy glycidyl ether and acryloyloxy glycidyl ether; oxygen heterocycles Butane acrylate, oxetane methacrylate and other compounds with (meth)acrylic group and oxetane group; lactone acrylate, lactone methacrylate, etc. have (methyl) ) Compounds of acrylic group and lactone group; compounds with vinyl and oxazoline groups such as vinyl oxazoline, isopropenyl oxazoline; isocyanatomethyl acrylate, isocyanatomethyl methacrylate, An oligomer of a compound having a (meth)acrylic group and an isocyanate group, such as 2-isocyanatoethyl acrylate or 2-isocyanatoethyl methacrylate, and the like. Moreover, the compound etc. which have a vinyl group, 1, 2- vinylene (vinylene), and an acid anhydride, such as methacrylic anhydride, an acrylic anhydride, maleic anhydride, or vinyl maleic anhydride, are mentioned. Among them, preferred are methacryloyloxy glycidyl ether, acryloyloxy glycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyloxazoline, and 2-isocyanatoethyl acrylate , 2-isocyanatoethyl methacrylate or the above-mentioned oligomer, particularly preferably isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate or the above-mentioned oligomer.

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

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

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

As the compound (YY), a commercially available product can be used as it is, or, if necessary, a commercially available product can be purified and used. As a commercial item, Laromer (registered trademark) LR-9000 (made by BASF Corporation) is mentioned, for example.

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, with respect to 100 parts by mass of the liquid crystal compound.

(Coating method of the composition for forming a polarizing layer)

As a method of applying the composition for forming a polarizing layer, extrusion coating method, direct gravure coating method, reverse gravure coating method, CAP coating method, slit coating method, microgravure method, die coating method, coating method, inkjet method, etc. Moreover, the method etc. which apply|coat using a coating machine, such as a dip coater, a bar coater, and a spin coater, are mentioned. Among them, in the case of continuous coating in a roll-to-roll format, a coating method using a microgravure method, an inkjet method, a slit coating method, or a die coating method is preferable. In the case of a monolithic substrate such as glass, a spin coating method with high uniformity is preferred. In the case of applying in a roll-to-roll format, the composition for forming an alignment film or the like may be applied on the base material layer 13 to form the alignment layer 12 , and the alignment layer 12 may be continuously formed on the obtained alignment layer 12 . The composition for forming a polarizing layer is applied.

When the polarizing layer forming composition is applied to form the polarizing layer 11, the solvent is removed from the applied polarizing layer forming composition to form a polarizing layer coating layer. As a method of removing a solvent, the same method as the method of removing a solvent from an oriented polymer composition can be utilized, for example, natural drying, ventilation drying, heating drying, drying under reduced pressure, and the method of combining these are mentioned. Among them, natural drying or heat drying is preferable. The drying temperature is preferably in the range of 0 to 200°C, more preferably in the range of 20 to 150°C, still more preferably in the range of 50 to 130°C. The drying time is preferably 10 seconds to 10 minutes, and more preferably 30 seconds to 5 minutes.

When the liquid crystal compound contained in the composition for forming a polarizing layer is a polymerizable liquid crystal compound, it is preferable to irradiate the coating layer for polarizing layers formed in the polarizing layer forming step with active energy rays to cause the polymerizable liquid crystal compound to react. photopolymerization, thereby forming the polarizing layer 11 . The active energy ray to be irradiated depends on the type of the polymerizable liquid crystal compound contained in the coating layer for polarizing layers (in particular, the type of the photopolymerizable functional group contained in the polymerizable liquid crystal compound), when a photopolymerization initiator is included. The following is appropriately selected according to the type of the photopolymerization initiator and the amount thereof. Specifically, one or more kinds of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-ray, α-ray, β-ray, and γ-ray can be mentioned. Among them, ultraviolet light is preferable from the viewpoints that it is easy to control the progress of the polymerization reaction and that an apparatus that has been widely used as a photopolymerization apparatus in this field can be used, and it is preferable to select the polymerization such that the photopolymerization can be performed by ultraviolet light. types of liquid crystal compounds.

Examples of light sources for active energy rays include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and emission wavelengths ranging from 380 to 440 nm. LED light source, chemical lamp, black light lamp, microwave excited mercury lamp, metal halide lamp, etc.

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

(Protective layer lamination process)

In the protective layer lamination step, as shown in FIG. 2( c ), on the polarizing layer 11 of the laminated film 62 prepared in the preparation step, a covering region 35 a for covering the polarizing layer 11 and a covering region 35 a for covering the polarizing layer 11 are laminated on the polarizing layer 11 . The protective layer 35 of the exposed area 35b is exposed. Thereby, the laminated film 63 with a protective layer can be obtained. The exposed region 35b can be formed as an opening of the protective layer 35, for example. The coating region 35 a can prevent the dissolving liquid from coming into contact with the polarizing layer 11 when the dissolving liquid capable of dissolving the polarizing layer 11 , which will be described later, is brought into contact with the laminated film 63 with the protective layer. On the other hand, in the exposed region 35 b of the protective layer 35 , the dissolving liquid can be brought into contact with the polarizing layer 11 .

As described later, when the polarizing layer 11 comes into contact with the dissolving liquid, the dissolving liquid dissolves the polarizing layer 11 . Therefore, the exposed region 35b is preferably formed corresponding to the region where the polarizing layer 11 is dissolved. For example, when manufacturing the polarizing film 1 shown in FIG.1 and FIG.2(e), it is preferable to determine the shape according to the shape of the low polarization area|region 11b. For example, when the plan view shape of the low polarization region 11b is a circle; an ellipse; an oval; a polygon such as a triangle, a square, a rectangle, and a rhombus; The area 35b is sufficient. In the case of a long polarizing film with a length of 10 m or more, it is possible to regularly form a circle; oval; oval; Compared with the prior art documents 1 and 2, the productivity is excellent.

For example, when the exposed region 35b is circular, the diameter thereof is preferably 5 cm or less, more preferably 3 cm or less, and further preferably 2 cm or less. When the exposed region 35b is elliptical or oval, the long axis is preferably 5 cm or less, more preferably 3 cm or less, and still more preferably 2 cm or less. When the exposed region 35b is a polygon, the diameter of an imaginary circle drawn so as to inscribe the polygon is preferably 5 cm or less, more preferably 3 cm or less, and still more preferably 2 cm or less. As described later, the dissolving liquid penetrates into the polarizing layer, and therefore, the size of the exposed region 35b can be formed to be slightly smaller than the low-polarization region 11b rather than the same size as the low-polarization region 11b.

In addition, the covering region 35a of the protective layer 35 is preferably formed so as to correspond to a region where the polarizing layer 11 is not dissolved. For example, when manufacturing the polarizing film 1 shown in FIG.1 and FIG.2(e), it is preferable to determine the shape according to the shape of the polarization region 11a.

As the protective layer 35, a product in which a region to be the exposed region 35b is formed on a sheet-like base material can be used. The region to be the exposed region 35b can be formed by a method of mechanically punching a predetermined portion of the sheet-like base material by punching, cutting plotter, water jet, or the like; A method of removing a predetermined portion of a sheet-like substrate by laser ablation, chemical dissolution, etc.; and the like.

The material of the sheet-like base material for forming the protective layer 35 is not particularly limited, as long as it is insoluble in the dissolving liquid when it comes into contact with the dissolving liquid capable of dissolving the polarizing layer 11 described later, and is used for dissolving the dissolving liquid, dissolved What is necessary is just a base material which has durability under the washing conditions performed by removing the polarizing layer. As a sheet-like base material for forming the protective layer 35, for example, it can be formed using the same material as the above-mentioned base material layer 13, and it is particularly preferred to use a resin base material, and it is more preferred to use a region that easily suppresses the exposure region 35b of the protective layer 35 Polyester resin such as polyethylene terephthalate which is deformed (for example, an opening).

The protective layer 35 preferably has an adhesive layer for sticking to the polarizing layer 11 . In order that the protective layer can be peeled off as described later, the adhesive layer is preferably peelable with respect to the polarizing layer 11 . 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.

(dissolving liquid contacting step)

In the dissolving solution contacting step, by contacting the laminated film 63 with the protective layer with the dissolving solution capable of dissolving the polarizing layer 11 , a patterned polarizing layer 11 ′ formed by removing a part of the polarizing layer 11 can be obtained. Film 64 with a patterned polarizer (FIG. 2(d)). Since the protective layer 35 of the laminated film 63 with a protective layer has a covering region 35a for covering the polarizing layer 11 and an exposed region 35b for exposing the polarizing layer 11, in the exposed region 35b, the solution can interact with the polarizing layer 35b. 11 Contacts. Thereby, the polarizing layer 11 in the contact part with a solution can be removed, and the area|region which does not contain a liquid crystal compound and a dichroic dye can be formed.

The contact between the laminated film 63 with a protective layer and the dissolving solution can be performed by immersing the laminated film 63 with a protective layer in the dissolving solution, coating, spraying, or dropping the dissolving solution on the laminated film 63 with a protective layer. It is preferable to carry out by the method of immersing the laminated|multilayer film 63 with a protective layer in a solution. Thereby, in the polarizing layer 11, the surface of the polarizing layer 11 exposed from the exposed region 35b of the protective layer 35 is brought into contact with the solution, and the liquid crystal compound and the dichroic dye are also removed. As a result, a patterned polarizing layer-attached film 64 in which a part of the polarizing layer 11 is removed to form the polarizing region 11a and the patterned polarizing layer 11' in which the polarizing region 11a and the low-polarization region 11b are formed is obtained (FIG. 2(d)).

Since the polarizing layer 11 is not in direct contact with the dissolving liquid in the area covered by the covering area 35 a of the protective layer 35 in the surface of the polarizing layer 11 , the polarizing layer 11 is not easily dissolved. On the other hand, in the polarizing layer 11 exposed from the exposed region 35b of the protective layer 35, since the polarizing layer 11 is in direct contact with the dissolving liquid, the polarizing layer 11 is easily dissolved, and the liquid crystal compound and the dichroic dye are easily dissolved. remove. Therefore, in the film 64 with the patterned polarizing layer shown in FIG. 2( d ), a patterned polarizing layer 11 ′ in which the polarizing layer 11 and the polarizing layer 11 in the polarizing layer 11 can be formed can be formed. The region corresponding to the covered region 35a has the polarizing layer 11 remaining, and the region corresponding to the exposed region 35b has a low polarization region 11b from which the liquid crystal compound and the dichroic dye have been removed.

As described above, by using the laminated film 63 with the protective layer in which the exposed region 35b of the protective layer 35 is arranged in the region where the liquid crystal compound and the dichroic dye forming the polarizing layer 11 are to be removed, it is possible to The patterned polarizing layer 11 ′ from which the liquid crystal compound and the dichroic dye have been removed is formed at a desired position of the polarizing layer 11 . The dissolving solution dissolves the polarizing layer 11. Therefore, it is preferable to adjust the thickness of the protective layer 35, the size of the exposed region 35b, the concentration of the dissolving solution, and the protective layer so as not to remove the polarizing layer 11 in unnecessary regions. The immersion time of the laminated film of the layer in the dissolving solution, the coating amount of the dissolving solution to the laminated film 63 with the protective layer, the amount of spraying, or the amount of dripping, and the like.

The dissolving liquid is not particularly limited as long as it dissolves the polarizing layer 11 and does not dissolve the base material layer 13 and the protective layer 35 , and is preferably an organic solvent. For example, aromatic hydrocarbons such as anisole and toluene, ethers such as tetrahydrofuran and dimethoxyethane, esters such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, and γ-butyrolactone can be mentioned. , acetone, methyl ethyl ketone, cyclopentanone and other ketones, chloroform and other chlorine-containing solutions, etc. These solvents may be used alone or in combination.

The contact conditions for bringing the protective layer-attached laminated film 63 into contact with the solution may be appropriately selected according to the thickness of the polarizing layer 11 , the size of the region from which the polarizing layer 11 is removed, and the like. The temperature of the dissolving solution is preferably 10 to 80°C, and more preferably 20 to 60°C.

In the dissolving liquid contacting step, it is preferable to provide a washing step of washing off the dissolving liquid and the dissolved polarizing layer after the protective layer-provided laminated film 63 is brought into contact with the dissolving liquid to remove a part of the polarizing layer 11 . The washing step can be appropriately performed using a substance that does not dissolve the polarizing layer 11 , such as water or alcohol.

(peeling process)

In the peeling step, the protective layer 35 is peeled off from the patterned polarizing layer-attached film 64 obtained in the liquid-substance contacting step. Thus, the polarizing film 1 including the patterned polarizing layer 11' having the polarizing region 11a and the low-polarizing region 11b can be obtained (FIG. 1 and FIG. 2(e)).

The polarizing film 1 shown in FIG.1 and FIG.2(e) can also be used by peeling the base material layer 13 further. In this case, the alignment layer 12 may be peeled off together with the base material layer 13 . For example, the peeling of the base material layer 13 may be performed after bonding the patterned polarizing layer 11' of the polarizing film 1 to a member forming a display device, a retardation layer, or the like.

(Method of Continuously Manufacturing Polarizing Film)

The manufacturing method of the polarizing film 1 is preferably continuous by a roll-to-roll method. In this case, in the preparation process, the laminated film wound in a roll shape is prepared, the laminated film is conveyed while being unwound, and the protective layer lamination process, the solution contact process, and the peeling process can be continuously performed. In the protective layer lamination step, the protective layer can be conveyed while unwinding the protective layer wound in a roll shape, and the protective layer can be laminated on the laminated film to obtain a laminated film with a protective layer. In the dissolving liquid contacting step, the laminated film with a protective layer may be continuously conveyed while passing the laminated film with a protective layer through a dissolving liquid bath filled with the dissolving liquid, or may be continuously conveyed while continuously conveying the laminated film with a protective layer The laminated film obtained by coating, spraying or dropping the dissolving solution to obtain a film with a patterned polarizing layer. In the peeling step, the protective layer can be continuously peeled off while conveying the film with the patterned polarizing layer, and the polarizing film can be wound into a roll shape to obtain 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 step includes an alignment layer forming step, the substrate layer may be conveyed while unwinding the substrate layer wound in a roll shape, and the alignment layer may be continuously applied to the substrate layer by a coating apparatus. The composition for formation is formed to form an alignment layer. When the preparation step includes a polarizing layer forming step, the polarizing layer may be coated on the side of the alignment layer-carrying substrate layer on which the alignment layer is formed while continuously conveying the alignment layer-carrying substrate layer. The composition for forming thereby forms a polarizing layer.

[Second Embodiment (Circularly Polarizing Plate and its Manufacturing Method)]

(circular polarizer)

FIGS. 3( a ) to ( c ) are schematic cross-sectional views showing an example of the circularly polarizing plate of the present invention, respectively. For the polarizing film 1 shown in Fig. 2(e), the circular polarizing plate 5a shown in Figs. 3(a) and (b) can be produced by laminating the retardation layer 15 having the function of a quarter-wave plate. , 5b. The retardation layer 15 may be laminated on the patterned polarizing layer 11' side of the polarizing film 1 ( FIG. 3( a )) or may be laminated on the base material layer 13 side ( FIG. 3( b )). In addition, a product obtained by peeling off the base material layer 13 from the circularly polarizing plate 5a shown in FIG. 3( a ) may be used as the circular polarizing plate 5c ( FIG. 3( c )). In this case, the The alignment layer 12 is peeled off together with the base material layer 13 .

In addition, the circularly polarizing plate may be obtained by laminating the polarizing film 1 and the retardation layer of the multilayer structure. In this case, a retardation layer obtained by laminating a layer having a half-wave plate function and a layer having a quarter-wave plate function can be used as the retardation layer of the multilayer structure. The layer side of the retardation layer having the function of a half wavelength plate is laminated with the polarizing film 1 to form a circular polarizing plate. Alternatively, a circularly polarizing plate can also be obtained by using a retardation layer obtained by laminating a layer having a 1/4 wavelength plate function with reverse wavelength dispersion and a layer having a positive C plate function as a retardation layer of a multilayer structure .

In addition, a layer having a function as a retardation layer can be used as the base layer 13 of the polarizing film 1, and a retardation layer can be further laminated to produce a circularly polarizing plate. In this case, the functions of the base material layer 13 and the retardation layer as retardation layers may be selected according to the lamination positions of the base material layer 13 and the retardation layer in the circularly polarizing plate.

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

(Manufacturing method of circularly polarizing plate)

The circularly polarizing plate can be produced by laminating a polarizing film and a retardation layer. In the case where the polarizing film is an elongated polarizing film having a length of 10 m or more produced continuously, it is preferable to use an elongated retardation layer having a length of 10 m or more as the above retardation layer, while continuously conveying both, The elongated polarizing film and the elongated retardation layer are laminated to form an elongated laminate. In this case, it is preferable to apply an adhesive or an adhesive to at least one of the elongated polarizing film and the elongated retardation layer, and to laminate both.

In order to attach the polarizing film to a display device having a predetermined size or the like, the method for producing a circular polarizing plate may include a single piece of cutting a long laminated body obtained by laminating a long polarizing film and a long retardation layer into a predetermined size. sheet process. In the cutting step, it is preferable to cut the elongated laminate along at least one of the longitudinal direction and the width direction of the elongated laminate. In this case, it is preferable to determine the cutting position in the elongated laminated body so that the low polarization region is arranged at a predetermined position in the single sheet obtained by cutting.

Example

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

Unless otherwise stated, "%" and "parts" in Examples and Comparative Examples mean mass % and mass parts.

[Visibility Corrected Polarization (Py) and Visibility Corrected Transmittance (Ty)]

(Preparation of samples for evaluation)

The composition for forming an alignment layer and the composition for forming a polarizing layer used in the respective Examples, Comparative Examples, and Reference Examples were prepared. Moreover, the same film as the film used as a base material layer in each Example, a comparative example, and a reference example was cut|disconnected to 40 mm x 40 mm, and was prepared as the base material layer of the sample for evaluation. A sample for evaluation was obtained by carrying out the same procedure as the production of the polarizing film of each of the Examples, Comparative Examples, and Reference Examples, except that the protective layer was not used using these.

(Visibility Corrected Polarization (Py) and Visibility Corrected Transmittance (Ty))

For the sample for evaluation, the visibility-corrected single transmittance (Ty) and the visibility-corrected polarization degree (Py) were calculated by the following procedure. In the wavelength range of 380 nm to 780 nm, using a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation) equipped with a polarizer with a polarizer, the transmission in the direction of the transmission axis was measured by the two-beam method. Transmittance (T ₁ ) and transmittance (T ₂ ) in the direction of the absorption axis. For this folder, a mesh blocking 50% of the amount of light was placed on the reference side. Using the following (Equation 1) and (Equation 2), the transmittance and the degree of polarization at each wavelength are calculated, and further, the visibility correction is performed using the 2-degree field of view (C light source) of JIS Z 8701, and the visibility correction transmittance is calculated. (Ty) and visibility corrected polarization (Py).

Degree of polarization [%]={(T ₁ -T ₂ )/(T ₁ +T ₂ )}×100 (Formula 1)

Monomer transmittance [%]=(T ₁ +T ₂ )/2 (Formula 2)

[Example 1]

(Manufacture of composition for forming alignment 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 as a composition for forming a photo-alignment film.

2 parts of a polymer having a photoreactive group shown below

Solvent: 98 parts of o-xylene

(Production of the composition for forming a polarizing layer)

The following components were mixed and stirred at 80° C. for 1 hour to obtain a composition for forming a polarizing layer. As the dichroic dye, the azo dye described in the examples of JP-A No. 2013-101328 was used.

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

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

・2.8 parts of dichroic dyes (1) shown below

・2.8 parts of dichroic dyes (2) shown below

・2.8 parts of dichroic dyes (3) shown below

6 parts of the following polymerization initiators

2-Dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by CibaSpecialty Chemicals, Inc.)

1.2 parts of leveling agent shown below

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

・250 parts of the solvent shown below

cyclopentanone

(Manufacture of polarizing film)

A triacetyl cellulose film (KC4UY-TAC manufactured by Konica Minolta Co., Ltd., thickness: 40 μm) as a base layer was cut into 20×20 mm, and the surface thereof was subjected to corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.). Using a bar coater, the composition for forming an alignment layer was applied to the surface of the film subjected to the corona treatment, and then dried in a drying oven set at 120° C. for 1 minute to obtain a coating layer for an alignment layer. Using a polarized UV light irradiation device (SPOT CURE SP-7; manufactured by USHIO INC.), with a cumulative light amount of 50 mJ/cm ² (based on 313 nm), the coating layer for alignment layer was irradiated at 0° with respect to the film edge. direction of the polarized UV light to form an alignment layer. Using a bar coater, the composition for forming a polarizing layer was applied onto the obtained alignment layer, and then dried in a drying oven set at 110° C. for 1 minute. Then, a high pressure mercury lamp (Uniicure VB-15201BY-A, manufactured by USHIO INC.) was used to irradiate ultraviolet rays (in a nitrogen atmosphere, wavelength: 365 nm, cumulative light intensity at a wavelength of 365 nm: 1000 mJ/cm ² ), thereby obtaining a liquid crystal compound and A polarizing layer in which a dichroic dye is oriented. A protective layer (AY-638, manufactured by Fujimori Kogyo Co., Ltd., manufactured by Fujimori Industry Co., Ltd.) was laminated on the polarizing layer by punching holes with a punch to form an opening. A polyester film having a thickness of 38 μm and a 15 μm-thick polyester film thereon were bonded. agent layer structure), and then immersed in anisole as a dissolving solution for 10 seconds. Then, the protective layer was peeled off to obtain a polarizing film.

The appearance of the obtained polarizing film was visually observed, and as a result, a circular region (low polarization region) in which no polarizing layer was present was clearly confirmed, and it was found that a polarizing film having a polarization region and a low polarization region was obtained. Moreover, the sample for evaluation was produced by the above-mentioned procedure, and the visibility correction transmittance (Ty) and the visibility correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Example 2]

As the base layer, instead of the triacetyl cellulose film, a quarter-wave plate for a uniaxially stretched film of a cyclic olefin resin was used (ZEONOR FILM, ZEON Co., Ltd., in-plane retardation value Ro: 138 nm) A polarizing film was obtained in the same manner as in Example 1, except that the film obtained by hard coating the surface of the film was laminated so that the slow axis and the absorption axis of the polarizing layer became 45°. The appearance of the obtained polarizing film was visually observed, and as a result, a circular region (low polarization region) in which no polarizing layer was present was clearly confirmed, and it was found that a polarizing film having a polarization region and a low polarization region was obtained. Moreover, the sample for evaluation was produced by the above-mentioned procedure, and the visibility correction transmittance (Ty) and the visibility correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Example 3]

Except having used tetrahydrofuran as a dissolving liquid, it carried out similarly to Example 1, and obtained the polarizing film. The appearance of the obtained polarizing film was visually observed, and as a result, a circular region (low polarization region) in which no polarizing layer was present was clearly confirmed, and it was found that a polarizing film having a polarization region and a low polarization region was obtained. Moreover, the sample for evaluation was produced by the above-mentioned procedure, and the visibility correction transmittance (Ty) and the visibility correction polarization degree (Py) were calculated. The results are shown in Table 1.

[Comparative example]

Except having used methanol as a dissolving liquid, it carried out similarly to Example 1, and obtained the polarizing film. The appearance of the obtained polarizing film was visually observed, and as a result, a region where no polarizing layer was present could not be confirmed, and it was found that a polarizing film having a polarizing region and a low-polarizing region was not obtained. Moreover, the sample for evaluation was produced by the above-mentioned procedure, and the visibility correction transmittance (Tv) and the visibility correction polarization degree (Pv) were calculated. The results are shown in Table 1.

[Reference example]

Except not using the dissolving liquid, it carried out similarly to Example 1, and obtained the polarizing film. The appearance of the obtained polarizing film was visually observed, and as a result, a region where no polarizing layer was present could not be confirmed, and it was found that a polarizing film having a polarizing region and a low-polarizing region was not obtained. Moreover, the sample for evaluation was produced by the above-mentioned procedure, and the visibility correction transmittance (Ty) and the visibility correction polarization degree (Py) were calculated. The results are shown in Table 1.

It should be noted that the values of the visibility-corrected transmittance (Ty) and the visibility-corrected polarization (Py) measured in each of the Examples, Comparative Examples, and Reference Examples shown in Table 1 are the values of the visibility-corrected transmittance including the base material layer. The value including the value of the transmittance (Ty) and the value of the visibility-corrected polarization (Py), the visibility-corrected transmittance (Ty) of the substrate layer alone is 92%, and the visibility-corrected polarization (Py) of the substrate layer is 92%. Since the value is 0%, it is considered that in each of the Examples, Comparative Examples, and Reference Examples shown in Table 1, when the base material layer is removed, the value of the visibility corrected transmittance (Ty) is larger than that shown in Table 1. The value of the visibility-corrected polarization (Py) is the same as that shown in Table 1.

[Table 1]

Description of reference numerals

1 polarizing film

5a～5c circular polarizer

11 Polarizing layer

11' patterned polarizer

11a Polarization area

11b Low polarization area

12 Orientation layer

13 Substrate layer

15 retardation layer

35 protective layer

35a Covered area

35b exposed area

61 Substrate layer with orientation layer

62 Laminated film

63 Laminated film with protective layer

64 Film with patterned polarizer

Claims (14)

1. The manufacturing method of polarizing film, it has the following steps: a preparation step of preparing a laminate film having a polarizing layer containing a dichroic dye on at least one side of the base material layer; The protective layer lamination step includes laminating a protective layer having a covering region for covering the polarizing layer and an exposed region for exposing the polarizing layer on the polarizing layer of the laminated film, thereby obtaining a protective layer. Laminated films of layers; The dissolving liquid contacting step of contacting the laminated film with the protective layer with a dissolving liquid capable of dissolving the polarizing layer, thereby obtaining a tape having a patterned polarizing layer formed by removing a partial region of the polarizing layer a film with a patterned polarizing layer; and In the peeling step, the protective layer is peeled off from the film with the patterned polarizing layer. 2. The method for producing a polarizing film according to claim 1, wherein the preparation step has the following steps: an alignment layer forming step of applying a composition for forming an alignment layer on one side of the base material layer to form an alignment layer; and A polarizing layer forming step of forming the polarized light by applying a composition for forming a polarizing layer containing a liquid crystal compound and the dichroic dye on the side of the base material layer on which the alignment layer is formed Floor. 3. The method for producing a polarizing film according to claim 2, wherein the composition for forming an alignment layer contains a photo-alignment polymer, In the said alignment layer formation process, the coating layer for alignment layers formed by apply|coating the said composition for alignment layer formation is irradiated with polarized light, and the said alignment layer is formed. The method for producing a polarizing film according to claim 2 or 3, wherein the polarizing layer is a layer in which a polymerizable liquid crystal compound is oriented, In the polarizing layer forming step, the coating layer for polarizing layers formed by applying the composition for forming polarizing layers is irradiated with active energy rays to form the polarizing layer. 5 . The method for producing a polarizing film according to claim 2 , wherein the polarizing layer exhibits a Bragg peak in X-ray diffraction measurement. 6 . 6. The method for manufacturing a polarizing film according to any one of claims 1 to 5, wherein a plan view shape of the exposed region is a circle, an ellipse, an oval, or a polygon, When the exposed area is circular, the diameter is 5 cm or less, When the exposed area is oval or oval, the long diameter is 5 cm or less, When the exposed area is a polygon, the diameter of an imaginary circle drawn so as to inscribe the polygon is 5 cm or less. The manufacturing method of the polarizing film in any one of Claims 1-6 whose length of the said polarizing film is 10 m or more. 8 . The method for producing a polarizing film according to claim 1 , wherein the base material layer has a quarter-wave plate function. 9 . 9. The manufacture method of circularly polarizing plate, it has following process: The retardation layer lamination step comprises laminating the polarizing film produced by the method for producing a polarizing film according to any one of claims 1 to 7 and a retardation layer having a quarter-wave plate function. 10 . The method for manufacturing a circular polarizing plate according to claim 9 , wherein the polarizing film is an elongated polarizing film with a length of 10 m or more, 10 . The retardation layer is an elongated retardation layer with a length of 10 m or more, In the retardation layer lamination step, by laminating the elongated polarizing film and the elongated retardation layer to form an elongated laminate, The manufacturing method further includes a cutting step of cutting the elongated laminate into individual pieces. 11. A polarizing film, which is a polarizing film having a polarizing region and a low-polarizing region, the low-polarizing region having a lower degree of visibility-corrected polarization than the polarizing region, the polarization region includes a liquid crystal compound and a dichroic dye, and the visibility correction polarization degree is 90% or more, The low polarization region does not contain liquid crystal compounds and dichroic dyes, The top view shape of the low polarization region is a circle, an ellipse, an oval or a polygon, When the low polarization region is circular, the diameter is 5 cm or less, When the low polarization region is elliptical or oval, the major axis is 5 cm or less, When the low polarization region is a polygon, the diameter of an imaginary circle drawn so as to inscribe the polygon is 5 cm or less. 12 . The polarizing film according to claim 11 , wherein the visibility correction polarization degree of the low polarization region is 10% or less. 13 . 13. The polarizing film according to claim 11 or 12, wherein the visibility correction monomer transmittance of the polarization region is 35% or more, The visibility correction single transmittance of the low polarization region is 80% or more. 14 . The polarizing film according to claim 11 , wherein the length of the polarizing film is 10 m or more. 15 .

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