Polarizing film and method for producing the same

Abstract

To provide a novel polarization film that although having at least two regions differing in visual sensitivity correction simplicial transmissivity, hardly has mutual region contours viewed, and can exhibit light absorption anisotropy on the whole.SOLUTION: There is provided a polarization film that includes a polarization layer and a base material layer, and that includes a first region and a second region adjoining the first region and having higher visual sensitivity correction simplicial transmissivity than the first region in a plane direction of the polarization film, the second region including a region X which has a difference of less than 30% in visual sensitivity correction simplicial transmissivity from the first region and also has a visual sensitivity correction polarization degree larger than 10%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polarizing film and a method for manufacturing the same.

Background Art

[0002] An organic EL display device using an organic light-emitting diode (OLED) can not only be made lighter and thinner compared to a liquid crystal display device or the like, but also can achieve high image quality such as a wide viewing angle, a fast response speed, and a high contrast. Therefore, it is used in various fields such as smartphones, televisions, and digital cameras. In an organic EL display device, an elliptical polarizing plate is used to suppress a decrease in visibility due to light reflection at the electrodes constituting the device and reflection of external light.

[0003] As a polarizing film used for such an elliptical polarizing plate, Patent Documents 1 to 3 disclose a patterned polarizing film in which a patterned polarizing layer is laminated on a substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional pattern polarizing film, as disclosed in Patent Documents 1 to 3 above, the single transmittance for visual sensitivity correction is low, and there is a polarizing region having a visual sensitivity correction degree of polarization within a general range that can function as a polarizing film (usually 90% or more), and a low polarization region having a high single transmittance for visual sensitivity correction and a significantly lower visual sensitivity correction degree of polarization than the polarizing region (usually 10% or less) are clearly visible. There has been no known polarizing film that has at least two regions with different single transmittances for visual sensitivity correction, in which the contour of each region is difficult to visually recognize, and the entire film can exhibit light absorption anisotropy.

[0006] An object of the present invention is to provide a novel polarizing film that has at least two regions with different single transmittances for visual sensitivity correction, in which the contour of each region is difficult to visually recognize, and the entire film can exhibit light absorption anisotropy, and a method for manufacturing the same. [Means for Solving the Problems]

[0007] As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention includes the following aspects. [1] A polarizing film including a polarizing layer and a base material layer, including a first region in the plane direction of the polarizing film and a second region adjacent to the first region and having a higher single transmittance for visual sensitivity correction than the first region, wherein the second region includes a region X in which the difference from the single transmittance for visual sensitivity correction of the first region is less than 30% and the visual sensitivity correction degree of polarization is greater than 10%, a polarizing film. [2] The polarizing film according to [1], wherein the region X continuously exists inward from the outer contour of the second region in contact with the first region. [3] The polarizing film according to [1] or [2], wherein the second region has at least two different single transmittances for visual sensitivity correction. [4] The polarizing film according to any one of [1] to [3], wherein the difference between the single transmittance for visual sensitivity correction of the second region and the single transmittance for visual sensitivity correction of the first region is less than 30% throughout the second region. [5] The single transmittance of the visual sensitivity correction of the first region is 30% or more and less than 55%, and the polarizing film according to any one of [1] to [4] above. [6] Region X has a single transmittance of visual sensitivity correction of 45% or more and 70% or less, and the polarizing film according to any one of [1] to [5] above. [7] Region X has a corrected polarization degree of visual sensitivity of 30% or more and 85% or less, and the polarizing film according to any one of [1] to [6] above. [8] The single transmittance of the visual sensitivity correction of the second region gradually increases from the outer contour of the second region toward the inside, and the polarizing film according to any one of [1] to [7] above. [9] The second region is composed of a region 2-1 in contact with the first region and a region 2-2 located inside the region 2-1. The single transmittance of the visual sensitivity correction of the region 2-2 is substantially uniform and higher than the single transmittance of the visual sensitivity correction in the region 2-1, and the polarizing film according to any one of [1] to [8] above.

[10] The single transmittance of the visual sensitivity correction of the region 2-1 gradually increases toward the region 2-2, and the polarizing film according to [9] above.

[11] The single transmittance of the visual sensitivity correction of the region 2-2 is 45% or more and 70% or less, and the polarizing film according to [9] or

[10] above.

[12] The planar shape of the second region is circular, elliptical, oval or polygonal, and the polarizing film according to any one of [1] to

[11] above.

[13] Having an alignment layer between the polarizing layer and the base material layer, and the polarizing film according to any one of [1] to

[12] above.

[14] The polarizing layer is composed of a cured layer of a liquid crystal composition containing a dichroic dye and a liquid crystal compound, and the polarizing film according to any one of [1] to

[13] above.

[15] An elliptical polarizing plate including the polarizing film according to any one of [1] to

[14] above and a retardation film.

[16] A method for manufacturing a polarizing film including at least two regions having different single transmittances of visual sensitivity correction in the plane direction, A step of forming a region having a first single transmittance of visual sensitivity correction, A step of forming, adjacent to the region having the first single transmittance for visual sensitivity correction, a region having a transmittance higher than the first single transmittance for visual sensitivity correction and a difference from the first single transmittance for visual sensitivity correction of less than 30% and a polarization degree for visual sensitivity correction of more than 10%. A method for manufacturing a polarizing film, comprising the above.

Advantages of the Invention

[0008] According to the present invention, there can be provided a novel polarizing film having at least two regions with different single transmittances for visual sensitivity correction, in which the region contours of each other are difficult to be visually recognized, and the whole film can exhibit light absorption anisotropy, and a method for manufacturing the same.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0011] <Polarizing Film> The polarizing film of the present invention includes a polarizing layer and a base material layer, and includes a first region and a second region that is adjacent to the first region in the plane direction and has a higher single transmittance for visual sensitivity correction than the first region. The second region includes a region X where the difference from the single transmittance for visual sensitivity correction of the first region is less than 30% and the polarized light degree for visual sensitivity correction is greater than 10%.

[0012] When the second region includes the region X, it can have the effect of making it difficult to visually recognize the region contours of the first region and the second region having different single transmittances for visual sensitivity correction from each other. As long as the above effect in the present invention is achieved, the region X may exist in any region within the second region. Since the boundary portion between the first region and the second region having different single transmittances for visual sensitivity correction is less likely to be noticeable and the effect of reducing the visibility of the two region contours is easily obtained, the region X preferably exists continuously from the outer contour of the second region in contact with the first region toward the inside.

[0013] In one aspect of the present invention, the second region has a substantially uniform visual sensitivity correction single transmittance (hereinafter, also referred to as "the first aspect"). Hereinafter, an example of the configuration of the polarizing film of the first aspect will be described with reference to the drawings. In FIG. 1 which is a schematic cross-sectional view showing an example of the polarizing film of the present invention, the polarizing film (11) of the present invention is composed of a base material layer (12) and a polarizing layer (13) laminated thereon. FIG. 2 is a plan view of the polarizing film (11) having the layer configuration as shown in FIG. 1, viewed from the side of the polarizing layer (13), and has a first region (1) in the plane direction of the polarizing film (11) and a second region (2) adjacent to the inside of the first region (1) in the plane direction. In FIG. 3 which schematically shows the visual sensitivity correction single transmittance at the *-* part of the polarizing film of FIG. 2, the visual sensitivity correction single transmittance (a) of the second region (2) is higher than the visual sensitivity correction single transmittance (b) of the first region (1) and is uniform over the entire second region (2). In this specification, "substantially uniform visual sensitivity correction single transmittance" means that the difference between the minimum value and the maximum value of the visual sensitivity correction single transmittance in the region is within 2%, and "uniform visual sensitivity correction single transmittance" means that the difference between the minimum value and the maximum value of the visual sensitivity correction single transmittance in the region is within 1%.

[0014] In the first aspect, the difference between the visual sensitivity correction single transmittance of the first region and the visual sensitivity correction single transmittance of the second region is less than 30%, preferably 25% or less, more preferably 20% or less. When the difference between the visual sensitivity correction single transmittance of the second region and the visual sensitivity correction single transmittance of the first region is below the above upper limit, the region contour between the first region and the second region becomes difficult to visually recognize, and the appearance difference between the first region and the second region can be reduced. The lower limit value of the difference between the visual sensitivity correction single transmittance of the first region and the visual sensitivity correction single transmittance of the second region in the first aspect may be appropriately determined according to the use of the polarizing film and the like, but usually exceeds 1%, preferably 2% or more, more preferably 3% or more.

[0015] In the first aspect, it is preferable that the second region is region X throughout. When the single transmittance of visual sensitivity correction of the second region is substantially uniform, usually, the polarization degree of visual sensitivity correction is also about the same. Therefore, the polarization degree of visual sensitivity correction of the second region is usually 10% or more, preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, particularly preferably 45% or more, and preferably 85% or less, more preferably 83% or less, still more preferably 81% or less. By having the polarization degree of visual sensitivity correction within the above range in the second region, it is possible to obtain a polarizing film in which the entire film exhibits light absorption anisotropy while being a film patterned into regions having different single transmittances of visual sensitivity correction.

[0016] In the polarizing film of the first aspect, it is preferable that the first region is a region having a polarization function required for a polarizing layer constituting a conventional general polarizing film, and usually has a substantially uniform single transmittance of visual sensitivity correction. The single transmittance of visual sensitivity correction is preferably 30% or more and less than 55%, more preferably 35% or more, still more preferably 38% or more, particularly preferably 40% or more, and more preferably 50% or less, still more preferably 48% or less, particularly preferably 45% or less.

[0017] In the polarizing film of the first aspect, the polarization degree of visual sensitivity correction of the first region is preferably 90% or more, more preferably 92% or more, still more preferably 95% or more. The upper limit of the single transmittance of visual sensitivity correction of the first region is not particularly limited and may be 100%.

[0018] In the polarizing film of the first aspect, the single transmittance of visual sensitivity correction of region X is preferably 45% or more and 70% or less, more preferably 45% or more and 65% or less, still more preferably 45% or more and 60% or less. When the single transmittance of visual sensitivity correction of region X in the polarizing film of the first aspect is within the above range, the effect of making the region contours between the first region and the second region less noticeable is likely to be enhanced.

[0019] In the polarizing film of the first aspect, the visually corrected polarization degree of region X is usually 10% or more, preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, and particularly preferably 45% or more. Also, it is preferably 85% or less, more preferably 83% or less, and still more preferably 81% or less. When the visually corrected polarization degree of region X in the polarizing film of the first aspect is within the above range, although it is a film patterned into regions having different visually corrected single transmittances, the entire film composed of the first region and region X (substantially the second region) becomes a polarizing film showing optical absorption anisotropy.

[0020] In the present invention, the visually corrected single transmittance (Ty) and the visually corrected polarization degree (Py) can be calculated based on the single transmittance and the polarization degree measured using a spectrophotometer. For example, in the range of wavelengths 380 nm to 780 nm which are visible light, the transmittance (T 1 ) in the transmission axis direction (perpendicular to the orientation) and the transmittance (T 2 ) in the absorption axis direction (same as the orientation) can be measured by the double beam method using an apparatus in which a folder with a polarizer is set in a spectrophotometer. The measurement diameter shall be a circular diameter of 1 mm. The single transmittance and the polarization degree in the visible light range are calculated for each wavelength using the following formulas (Formula 1) and (Formula 2), and further, the visually corrected single transmittance (Ty) and the visually corrected polarization degree (Py) can be calculated by performing visual sensitivity correction with a 2-degree field of view (C light source) of JIS Z 8701. Specifically, it can be measured and calculated according to the method described in the examples described later. Single transmittance [%] = (T 1 + T 2 ) / 2 (Formula 1) Polarization degree [%] = { (T 1 - T 2 ) / (T 1 + T 2 )} × 100 (Formula 2)

[0021] By controlling the single transmittance of visual sensitivity correction in multiple stages within the second region, it becomes easier to blur the region contours between the first region and the second region, and it is also possible to provide a region having a higher single transmittance of visual sensitivity correction within the second region compared to the first aspect. Therefore, in another aspect of the present invention, the second region has at least two different single transmittances of visual sensitivity correction (hereinafter, also referred to as "second aspect"). In this case, since a region with a lower single transmittance of visual sensitivity correction exists in the second region adjacent to the first region, the boundary portion between the first region and the second region becomes less conspicuous, and the effect of reducing the visibility of the region contour is excellent. Therefore, in the second aspect, it is preferable that the single transmittance of visual sensitivity correction on the outer side of the second region adjacent to the first region is lower than the single transmittance of visual sensitivity correction inside the second region, and it is more preferable that at least the second region adjacent to the first region is region X.

[0022] In the second aspect, it is preferable that the single transmittance of visual sensitivity correction in the second region increases stepwise from the outer contour to the inside of the second region. When the single transmittance of visual sensitivity correction in the second region increases from the outer contour of the second region adjacent to the first region to the inside, the boundary portion between the first region and the second region becomes less conspicuous, and the effect of reducing the visibility of the region contour is excellent. Examples of the aspect when the single transmittance of visual sensitivity correction in the second region increases stepwise include the aspects shown in FIGS. 4, 6, and 8.

[0023] FIG. 4 is a plan view of a polarizing film (11) having a layer structure as shown in FIG. 1, viewed from the side of the polarizing layer (13). The polarizing film (11) has a first region (1) in the plane direction and a second region (2) adjacent to the inside of the first region (1) in the plane direction. The second region (2) is further composed of a region 2-1 (3) in contact with the first region and a region 2-2 (4) located inside the region 2-1 (3) in the plane direction. In FIG. 5 schematically showing the single transmittance of visual sensitivity correction at the *-* part of the polarizing film in FIG. 4, the single transmittance of visual sensitivity correction of the second region (2) is higher than that of the first region (1) (b), and the single transmittance of visual sensitivity correction of the region 2-2 (4) constituting the second region (a-2) is higher than that of the region 2-1 (3) (a-1).

[0024] In the polarizing film (11) shown in FIG. 4, the single transmittance of visual sensitivity correction of the region 2-2 (4) is substantially uniform as shown in FIG. 5, and the region 2-1 (3) consists of one region having a substantially uniform single transmittance of visual sensitivity correction (a-1). By providing a region 2-1 between the region 2-2 having the highest single transmittance of visual sensitivity correction in the second region and the first region, with a single transmittance of visual sensitivity correction higher than that of the first region and lower than that of the region 2-2, the effect of making the region contour between the first region and the second region less noticeable can be enhanced. The single transmittance of visual sensitivity correction of the region 2-1 may be increased in multiple steps by two or more regions each having a substantially uniform single transmittance of visual sensitivity correction. In this case, among the plurality of regions having a substantially uniform single transmittance of visual sensitivity correction constituting the second region, the region having the highest single transmittance of visual sensitivity correction becomes the region 2-2, and the other regions become the region 2-1.

[0025] Further, the single transmittance of the visual sensitivity correction in region 2-1 may gradually increase in a gradient manner toward region 2-2 having a substantially uniform single transmittance of the visual sensitivity correction. FIG. 6 is a plan view showing an example of a polarizing film (11) in which the single transmittance of the visual sensitivity correction in region 2-1 (3) increases in a gradient manner toward region 2-2 (4). In FIG. 7 schematically showing the single transmittance of the visual sensitivity correction at the *-* part of the polarizing film of FIG. 6, the single transmittance of the visual sensitivity correction (a-2) in region 2-2 (4) is substantially uniform, and is higher than the single transmittance of the visual sensitivity correction (a-1) in region 2-1 (3), and the single transmittance of the visual sensitivity correction in region 2-1 (3) increases in a gradient manner toward region 2-2 (4).

[0026] When the single transmittance of the visual sensitivity correction (a-1) in region 2-1 (3) increases stepwise toward region 2-2 (4), the effect of making the region contour between the first region and the second region less noticeable is enhanced, and even when region 2-2 (4) having a relatively high single transmittance of the visual sensitivity correction is provided, the appearance difference between the first region and the second region tends to be small. Therefore, in one aspect of a preferred polarizing film in the second aspect of the present invention, the second region is composed of region 2-1 in contact with the first region and region 2-2 located inside the region 2-1, the single transmittance of the visual sensitivity correction in region 2-2 is substantially the same, and is higher than the single transmittance of the visual sensitivity correction in region 2-1, and the single transmittance of the visual sensitivity correction in region 2-1 increases stepwise toward region 2-2.

[0027] The second region may stepwise increase from the outer contour of the second region adjacent to the first region toward a point within the second region without including region 2-2 having a substantially uniform visual sensitivity correction single transmittance. FIG. 8 is a plan view showing an example of such an aspect, and the polarizing film (11) has a first region (1) in the plane direction and a second region (2) adjacent to the inside of the first region (1) in the plane direction. In FIG. 9 schematically showing the visual sensitivity correction single transmittance at the *-* part of the polarizing film in FIG. 8, the visual sensitivity correction single transmittance (a) of the second region (2) is higher than the visual sensitivity correction single transmittance (b) of the first region 1, and gradually increases from the outer contour of the second region (2) toward a point within the second region (2). Also in this aspect, the visual sensitivity correction single transmittance of the second region may increase in multiple steps by two or more regions each having a substantially uniform visual sensitivity correction single transmittance.

[0028] The position of region 2-2 within the second region and the position of the above-mentioned "point" (hereinafter also referred to as "center point") when the visual sensitivity correction single transmittance of the second region increases toward a point within the second region may be appropriately selected according to the shape of the second region, the use of the polarizing film, etc., and may be located anywhere within the second region. Usually, region 2-2 and the center point within the second region are preferably located in any of the second regions not in contact with the first region because they are the region or point having the highest visual sensitivity correction single transmittance within the second region. Also, when the visual sensitivity correction single transmittance of the second region increases toward the inside of the second region, if the visual sensitivity correction single transmittance increases concentrically from the outer contour of the second region toward region 2-2 or the center point, it becomes easier to suppress the visual recognition of the region contour due to the different visual sensitivity correction single transmittances within the second region.

[0029] In a second aspect, the difference between the minimum value and the maximum value of the single transmittance of visual sensitivity correction in the second region is preferably less than 30%, more preferably 25% or less, and still more preferably 20% or less. When the difference in the single transmittance of visual sensitivity correction in the second region is within the above range, it is excellent in the effect of making it difficult to visually recognize the region contour that can be visually recognized due to the difference in the single transmittance of visual sensitivity correction in the second region. The lower limit value of the difference in the single transmittance of visual sensitivity correction in the second region may be appropriately determined according to the use of the polarizing film, the size of the second region, etc., and usually exceeds 1%, preferably 3% or more, and more preferably 5% or more.

[0030] In a second aspect, the difference between the single transmittance of visual sensitivity correction in the second region and the single transmittance of visual sensitivity correction in the first region is preferably less than 30% throughout the second region, more preferably 25% or less, and still more preferably 20% or less. When the difference from the single transmittance of visual sensitivity correction in the first region is within the above upper limit throughout the second region, it becomes difficult to visually recognize the region contours of the first region and the second region, and the appearance difference between the first region and the second region can be reduced. The lower limit value of the difference between the single transmittance of visual sensitivity correction in the first region and the single transmittance of visual sensitivity correction in the second region in the first aspect may be appropriately determined according to the distribution of each region having different single transmittances of visual sensitivity correction in the second region, the use of the polarizing film, etc. For example, when the second region has a single transmittance of visual sensitivity correction as shown in FIG. 5, the lower limit value usually exceeds 1%, preferably 2% or more, and more preferably 3% or more. When the second region has a single transmittance of visual sensitivity correction as shown in FIGS. 7 and 9, the lower limit value is not particularly limited as long as the single transmittance of visual sensitivity correction in the second region is higher than the single transmittance of visual sensitivity correction in the first region.

[0031] In the second aspect, the entire second region may be region X, or a part of the second region may be region X. When the second region is composed of region 2-1 and region 2-2, a part of region 2-1 may be region X, only region 2-1 may be region X, or both region 2-1 and region 2-2 may be region X. As the area of region X in the second region increases, there is a tendency to be excellent in the effect of reducing the visibility of the region contours of the first region and the second region.

[0032] Since it is easy to obtain the effect of making the boundary portion between the first region and the second region less conspicuous by having region X occupy an area equal to or greater than a certain value with respect to the total area of the second region, it is preferable to provide region X inward from the outer contour of the second region so that the area of region X is equal to or greater than a certain value with respect to the total area of the second region. The area of region X with respect to the total area of the second region is, for example, 30% or more, preferably 40% or more, more preferably 50% or more, still more preferably 60% or more, particularly preferably 70% or more, and most preferably 80% or more. It is preferable to provide region X inward from the outer contour of the second region in contact with the first region, preferably continuously, so as to satisfy the above conditions. In one aspect of the present invention, the entire second region is region X (that is, the area of region X with respect to the total area of the second region is 100%).

[0033] In the polarizing film of the second aspect, the first region preferably has a polarizing function required for a polarizing layer constituting a conventional general polarizing film, and usually has a substantially uniform visual sensitivity correction single transmittance. The visual sensitivity correction single transmittance is preferably 30% or more and less than 55%, more preferably 35% or more, still more preferably 38% or more, particularly preferably 40% or more, and also more preferably 50% or less, still more preferably 48% or less, particularly preferably 45% or less.

[0034] In the polarizing film of the second aspect, the visual sensitivity correction degree of polarization of the first region is preferably 90% or more, more preferably 92% or more, still more preferably 95% or more. The upper limit of the visual sensitivity correction single transmittance of the first region is not particularly limited and may be 100%.

[0035] In the polarizing film of the second aspect, the single transmittance of the visual sensitivity correction in region X is preferably 45% or more and 70% or less, more preferably 45% or more and 65% or less, and still more preferably 45% or more and 60% or less. When the single transmittance of the visual sensitivity correction in region X in the polarizing film of the first aspect is within the above range, the effect of making the region contours of the first region and the second region less prominent is likely to be enhanced. When the second region consists of region 2-1 and region 2-2, it is preferable that the single transmittance of the visual sensitivity correction in region 2-2 is within the above range.

[0036] In the polarizing film of the second aspect, the degree of polarization of the visual sensitivity correction in region X is usually 10% or more, preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, and particularly preferably 45% or more. Also, it is preferably 85% or less, more preferably 83% or less, and still more preferably 81% or less. When the degree of polarization of the visual sensitivity correction in region X in the polarizing film of the first aspect is within the above range, although it is a film patterned in regions having different single transmittances of the visual sensitivity correction, the entire film composed of the first region and region X (substantially the second region) becomes a polarizing film showing light absorption anisotropy. When the second region consists of region 2-1 and region 2-2, it is preferable that the degree of polarization of the visual sensitivity correction in region 2-2 is within the above range.

[0037] In the polarizing film of the second aspect, the maximum value of the single transmittance of the visual sensitivity correction in the second region is preferably 95% or less, more preferably 90% or less, still more preferably 85% or less, particularly preferably less than 80%, especially preferably 75% or less, and even more preferably 70% or less. The minimum value of the single transmittance of the visual sensitivity correction in the second region is preferably 45% or more. When the second region consists of region 2-1 and region 2-2, usually, the maximum value of the single transmittance of the visual sensitivity correction in region 2-2 is within the range of the maximum value of the single transmittance of the visual sensitivity correction in the second region.

[0038] In the polarizing film of the second aspect, the minimum value of the visual sensitivity correction polarization degree in the second region may be, for example, 0%, preferably 10% or more, more preferably 20% or more, and still more preferably 30% or more. When the second region consists of region 2-1 and region 2-2, usually, the minimum value of the visual sensitivity correction single transmittance of region 2-2 falls within the range of the minimum value of the visual sensitivity correction single transmittance in the second region.

[0039] The ratios of the occupied areas of the first region and the second region to the total area of the polarizing film of the present invention may be appropriately selected according to the use of the polarizing film, the required characteristics, etc. The ratio of the total of the occupied areas of the first region and the second region to the total area of the surface of the polarizing film is preferably 90% or more, more preferably 95% or more, and still more preferably 99% or more.

[0040] The occupied area of the first region with respect to the total area of the occupied areas of the first region and the second region is preferably 50% or more, more preferably 70% or more, and still more preferably 80% or more.

[0041] The occupied area of the second region with respect to the total area of the occupied areas of the first region and the second region is preferably 50% or less, more preferably 30% or less, and still more preferably 20% or less. In the polarizing film of the present invention, a plurality of second regions may be provided independently within the first region.

[0042] In the polarizing film of the present invention, when the second region is composed of region 2-1 and region 2-2, the ratio of the occupied area of region 2-1 to the surface area of the second region is not particularly limited, but is, for example, 20% or more, preferably 30% or more. Further, when the second region is composed of region 2-1 and region 2-2, the ratio of the occupied area of region 2-2 to the surface area of the second region is, for example, 20% or more, preferably 30% or more, and also, for example, 80% or less, preferably 70% or less.

[0043] In the polarizing film of the present invention, the shape of the second region may be appropriately determined according to the distribution of each region having different visual sensitivity correction single transmittance within the second region, the use of the polarizing film, and the like. The planar shape of the second region may be, for example, circular; elliptical; oval; polygonal such as triangular, square, rectangular, rhombic; letter shape; combinations thereof, etc., and may be any shape. From the viewpoint of ease of processing when forming the second region, etc., it is preferably circular, elliptical, oval or polygonal.

[0044] When the second region is circular, its diameter is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the second region is elliptical or oval, its major axis is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less. When the second region is polygonal, the diameter of the virtual circle drawn so that the polygon is inscribed therein is preferably 5 cm or less, more preferably 3 cm or less, and even more preferably 2 cm or less.

[0045] In addition, when the polarizing film is a long polarizing film, since the long polarizing film is usually cut into a predetermined size according to the use of the polarizing film and the like, it is preferable to set the arrangement of the first region and the second region in the long polarizing film so that the first region and the second region are formed at predetermined positions of the cut polarizing film.

[0046] (Base material layer) In the present invention, the base material layer is not particularly limited as long as it can support the polarizing layer and the alignment layer when manufacturing the polarizing film, and a base material known in the art can be used. Examples of the base material include a glass base material and a resin base material, and a resin base material is preferable from the viewpoint of being able to continuously manufacture a long polarizing film. The resin base material is preferably a base material having light transmittance capable of transmitting visible light. Here, the light transmittance means that the visual sensitivity correction single transmittance is 80% or more with respect to light in the wavelength range of 380 to 780 nm.

[0047] Examples of the resin constituting the resin substrate include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylate; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose, and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyetherketone; polyphenylene sulfide, and polyphenylene oxide; and the like.

[0048] Examples of commercially available resin substrates of cellulose ester include "Fujitac Film" (manufactured by Fujifilm Corporation); "KC8UX2M", "KC8UY", and "KC4UY" (all manufactured by Konica Minolta Opto, Inc.).

[0049] Examples of commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona GmbH), "Arton" (registered trademark) (manufactured by JSR Corporation), "Zeonor" (registered trademark), "Zeonex" (registered trademark) (both manufactured by Zeon Corporation), and "Apel" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such cyclic olefin resins can be formed into a film by known means such as the solvent casting method and the melt extrusion method to obtain a resin substrate. It is also possible to use a resin substrate of a commercially available cyclic olefin resin. Examples of commercially available resin substrates of cyclic olefin resins include "ESINA" (registered trademark), "SCA40" (registered trademark) (both manufactured by Sekisui Chemical Co., Ltd.), "Zeonor Film" (registered trademark) (manufactured by Optes Co., Ltd.), and "Arton Film" (registered trademark) (manufactured by JSR Corporation).

[0050] The thickness of the base material layer is preferably thin in terms of having a mass that allows for practical handling. However, from the perspectives of strength and processability, it is usually 5 μm to 300 μm, preferably 20 μm to 200 μm. Further, the base material layer may be provided so as to be peelable. For example, after laminating the patterned polarizing layer of the polarizing film to a member forming a display device or a retardation film described later, it may be peelable from the polarizing film. Thereby, a further thinning effect of the polarizing film can be obtained.

[0051] The base material layer may have a single-layer structure or a multilayer structure of two or more layers. When the base material layer has a multilayer structure, each layer may be formed from the same material or may be formed from different materials.

[0052] Further, the base material layer may have a retardation function such as a 1 / 4 wavelength plate function. By the base material layer having a retardation function, a polarizing film having the function of an elliptical polarizing plate can be obtained by combining the base material layer and the patterned polarizing layer. Thereby, an elliptical polarizing plate can be obtained without laminating a retardation film separately from the base material layer to the polarizing film. Further, when the base material layer has a multilayer structure, an elliptical polarizing plate can be obtained by using a laminate of a layer having a 1 / 2 wavelength plate function and a layer having a 1 / 4 wavelength plate function and laminating the patterned polarizing layer on the layer side having the 1 / 2 wavelength plate function. Alternatively, when the base material layer has a multilayer structure, an elliptical polarizing plate can also be obtained by using a laminate of a layer having a 1 / 4 wavelength plate function with reverse wavelength dispersion and a layer having a positive C plate function.

[0053] (Polarizing layer) In the present invention, the polarizing layer is a layer having a polarizing function, and is not particularly limited as long as a first region and a second region can be formed in the plane of the layer. As the polarizing layer, those generally used as conventional polarizing films can be used. For example, a stretched film adsorbed with a dye having absorption anisotropy or a film coated with a dye having absorption anisotropy and containing a polarizer such as a film (layer) can be mentioned. Examples of the dye having absorption anisotropy include dichroic dyes.

[0054] A polarizing layer containing a stretched film adsorbed with a dye having absorption anisotropy as a polarizer is usually produced by uniaxially stretching a polyvinyl alcohol-based resin film, dyeing the polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye, treating the polyvinyl alcohol-based resin film adsorbed with the dichroic dye with an aqueous boric acid solution, and washing with water after treatment with the aqueous boric acid solution. It is produced by sandwiching at least one surface of the polarizer thus produced between transparent protective films via an adhesive.

[0055] The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having an ammonium group, and the like.

[0056] The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably in the range of 1,500 to 5,000.

[0057] A film made of such a polyvinyl alcohol-based resin is used as the raw film for the polarizing layer. The method for forming a film of the polyvinyl alcohol-based resin is not particularly limited, and a film can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film can be, for example, about 10 to 150 μm.

[0058] Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. Also, it is possible to perform uniaxial stretching in a plurality of these steps. For uniaxial stretching, stretching may be performed uniaxially between rolls with different peripheral speeds, or stretching may be performed uniaxially using a hot roll. Also, the uniaxial stretching may be dry stretching performed in the air, or wet stretching performed using a solvent and stretching the polyvinyl alcohol-based resin film in a swollen state. The stretching ratio is usually about 3 to 8 times.

[0059] Dyeing of the polyvinyl alcohol-based resin film with a dichroic dye is performed, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye.

[0060] Specifically, iodine and dichroic organic dyes are used as the dichroic dye. Examples of the dichroic organic dye include dichroic direct dyes composed of disazo compounds such as C.I. DIRECT RED 39, and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo. It is preferable that the polyvinyl alcohol-based resin film is subjected to an immersion treatment in water before the dyeing treatment.

[0061] When iodine is used as the dichroic pigment, a method is usually adopted in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing iodine and potassium iodide for dyeing. The iodine content in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water. The potassium iodide content is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. Also, the immersion time (dyeing time) in this aqueous solution is usually about 20 to 1,800 seconds.

[0062] On the other hand, when a dichroic organic dye is used as the dichroic pigment, a method is usually adopted in which a polyvinyl alcohol-based resin film is immersed in an aqueous solution containing a water-soluble dichroic dye for dyeing. The content of the dichroic organic dye in this aqueous solution is usually about 1×10 -4 ~10 parts by mass, preferably 1×10 -3 ~1 part by mass, and more preferably 1×10 -3 ~1×10 -2 parts by mass. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80°C. Also, the immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

[0063] The boric acid treatment after staining with a dichroic dye can usually be carried out by immersing the stained polyvinyl alcohol-based resin film in an aqueous boric acid solution. The content of boric acid in this aqueous boric acid solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. When iodine is used as the dichroic dye, this aqueous boric acid solution preferably contains potassium iodide, and the content of potassium iodide in that case is usually about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water. The immersion time in the aqueous boric acid solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, more preferably 200 to 400 seconds. The temperature of the boric acid treatment is usually 50°C or higher, preferably 50 to 85°C, more preferably 60 to 80°C.

[0064] The polyvinyl alcohol-based resin film after the boric acid treatment is usually subjected to a water washing treatment. The water washing treatment can be carried out, for example, by immersing the boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of the water in the water washing treatment is usually about 5 to 40°C. Also, the immersion time is usually about 1 to 120 seconds.

[0065] After the water washing, a drying treatment is performed to obtain a polarizer. The drying treatment can be carried out, for example, using a hot air dryer or a far-infrared heater. The temperature of the drying treatment is usually about 30 to 100°C, preferably 50 to 80°C. The time of the drying treatment is usually about 60 to 600 seconds, preferably 120 to 600 seconds. By the drying treatment, the moisture content of the polarizer is reduced to a practical level. The moisture content is usually about 5 to 20% by mass, preferably 8 to 15% by mass. When the moisture content is within the above range, a polarizer having appropriate plasticity and excellent thermal stability can be obtained.

[0066] Thus, the thickness of the polarizing layer obtained by subjecting the polyvinyl alcohol-based resin film to uniaxial stretching, staining with a dichroic dye, boric acid treatment, water washing, and drying is preferably 5 to 40 μm.

[0067] When using a stretched film adsorbed with the dichroic dye as described above as the polarizing layer, a laminated film including a base material layer and a polarizing layer can be obtained by laminating a polarizing layer made of a stretched film on the base material layer via an adhesive layer or the like.

[0068] Examples of the film coated with a dye having absorption anisotropy include films obtained by coating a composition containing a liquid crystalline dichroic dye or a polymerizable liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound. A polarizing film using a film formed from such a liquid crystalline composition as the polarizing layer is advantageous in terms of thinning and productivity as compared with a polarizing film including a polarizing layer made of a stretched film. Therefore, in the present invention, it is preferable that the polarizing layer is composed of a cured layer of a liquid crystal composition containing a dichroic dye and a liquid crystal compound.

[0069] In the polarizing film of the present invention, the liquid crystal compound contained in the liquid crystal composition for forming the polarizing layer is not particularly limited, and a liquid crystal compound known in the field of optical films can be used as long as a layer having a polarizing function can be formed. Examples of the liquid crystal compound include rod-shaped liquid crystal compounds, disk-shaped liquid crystal compounds, and mixtures thereof. Further, the liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof.

[0070] By using a polymerizable liquid crystal compound, the hue of the polarizing film can be arbitrarily controlled and the polarizing film can be significantly thinned. Therefore, it is preferable to use a polymerizable liquid crystal compound as the liquid crystal compound. Further, since the polarizing film can be manufactured without performing a stretching treatment, it is also advantageous in that a non-stretchable polarizing film without relaxation of stretching due to heat can be obtained.

[0071] In the present invention, the polymerizable liquid crystal compound (hereinafter also referred to as "polymerizable liquid crystal compound (A)") contained in the polymerizable liquid crystal composition for forming a polarizing layer (hereinafter also referred to as "polymerizable liquid crystal composition (A)") is a liquid crystal compound having at least one polymerizable group. Here, the polymerizable group refers to a group that can participate in a polymerization reaction by active radicals, acids, etc. generated from a polymerization initiator. Examples of the polymerizable group of the polymerizable liquid crystal compound (A) include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, an oxetanyl group, and the like. Among them, a radical polymerizable group is preferable, an acryloyloxy group, a methacryloyloxy group, a vinyl group, and a vinyloxy group are more preferable, and an acryloyloxy group and a methacryloyloxy group are preferable.

[0072] In the present invention, the polymerizable liquid crystal compound (A) is preferably a compound exhibiting nematic liquid crystallinity or smectic liquid crystallinity, and more preferably a compound exhibiting smectic liquid crystallinity. By using a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity, a polarizer with a high degree of alignment order can be formed. The liquid crystal state exhibited by the polymerizable liquid crystal compound (A) is a smectic phase (smectic liquid crystal state), and from the viewpoint of realizing a higher degree of alignment order, it is more preferably a higher-order smectic phase (higher-order smectic liquid crystal state). Here, the higher-order smectic phase means a smectic B phase, a smectic D phase, a smectic E phase, a smectic F phase, a smectic G phase, a smectic H phase, a smectic I phase, a smectic J phase, a smectic K phase, and a smectic L phase. Among these, a smectic B phase, a smectic F phase, and a smectic I phase are more preferable. The liquid crystallinity may be thermotropic liquid crystal or lyotropic liquid crystal, but thermotropic liquid crystal is preferable in terms of enabling precise film thickness control. Further, the polymerizable liquid crystal compound (A) may be a monomer, but may also be an oligomer or a polymer in which the polymerizable groups are polymerized.

[0073] As the polymerizable liquid crystal compound (A), there is no particular limitation as long as it is a liquid crystal compound having at least one polymerizable group, and known polymerizable liquid crystal compounds can be used, but compounds exhibiting smectic liquid crystallinity are preferred. Examples of such polymerizable liquid crystal compounds include compounds represented by the following formula (A1) (hereinafter also referred to as "polymerizable liquid crystal compound (A1)"). U 1 -V 1 -W 1 -(X 1 -Y 1 -) n -X 2 -W 2 -V 2 -U 2 (A1) [In formula (A1), X 1 and X 2 each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, where the hydrogen atoms contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom or a nitrogen atom. However, at least one of X 1 and X 2 is a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent. Y 1 is a single bond or a divalent linking group. n is 1 to 3, and when n is 2 or more, the plurality of X 1 may be the same as or different from each other. X 2 may be the same as or different from any or all of the plurality of X 1 . Also, when n is 2 or more, the plurality of Y 1 may be the same as or different from each other. From the viewpoint of liquid crystallinity, n is preferably 2 or more. U 1represents a hydrogen atom or a polymerizable group. U 2 represents a polymerizable group. W 1 and W 2 are, independently of each other, a single bond or a divalent linking group. V 1 and V 2 are, independently of each other, an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and the -CH 2 - constituting the alkanediyl group may be replaced by -O-, -CO-, -S- or NH-.

[0074] In the polymerizable liquid crystal compound (A1), X 1 and X 2 are, independently of each other, preferably an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, and at least one of X 1 and X 2 is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, and is preferably a trans-cyclohexane-1,4-diyl group. Examples of the optionally substituent of the optionally substituted 1,4-phenylene group or the optionally substituted cyclohexane-1,4-diyl group include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group and butyl group, cyano group and halogen atoms such as chlorine atom and fluorine atom. It is preferably unsubstituted.

[0075] Also, in the polymerizable liquid crystal compound (A1), in formula (A1), formula (A1-1): -(X 1 -Y 1 -) n -X 2 - (A1-1) 〔In the formula, X 1 , Y 1 , X 2 and n have the same meanings as described above, respectively.〕 The part shown by [hereinafter referred to as substructure (A1-1).] being an asymmetric structure is preferable in that it easily exhibits smectic liquid crystallinity. Examples of the polymerizable liquid crystal compound (A1) in which the substructure (A1-1) is an asymmetric structure include where n is 1 and one X 1 and X 2 are different from each other. Also, where n is 2 and two Ys 1 are the same as each other, and two Xs 1 are the same as each other, and one X 2 is different from these two Xs 1 in structure. The polymerizable liquid crystal compound (A1), where one of the two Xs 1 bonded to W 1 is different from the other X 1 and the other X 1 and X 2 and the other X 1 and X 2 are the same as each other. The polymerizable liquid crystal compound (A1) is also included. Furthermore, where n is 3 and three Ys 1 are the same as each other, and any one of the three Xs 1 and one X 2 is different from all the other three. The polymerizable liquid crystal compound (A1) is included.

[0076] Y 1 is preferably -CH 2 CH 2 -, -CH 2 O-, -CH 2 CH 2 O-, -COO-, -OCOO-, single bond, -N=N-, -CR a =CR b -, -C≡C-, -CR a =N- or -CO-NR a -. R a and R bEach independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y 1 is preferably -CH 2 CH 2 -, -COO- or a single bond, and when there are a plurality of Y 1 present, the Y 2 bonded to X 1 is preferably -CH 2 CH 2 - or -CH 2 O-. When X 1 and X 2 have the same structure, it is preferable that there are two or more Y 1 with different bonding modes. When there are a plurality of Y 1 with different bonding modes, an asymmetric structure is formed, and thus smectic liquid crystallinity tends to be easily exhibited.

[0077] U 2 is a polymerizable group. U 1 is a hydrogen atom or a polymerizable group, preferably a polymerizable group. U 1 and U 2 are preferably both polymerizable groups, and preferably both radical polymerizable groups. Examples of the polymerizable group include the same groups as those exemplified above as the polymerizable group of the polymerizable liquid crystal compound (A). The polymerizable group represented by U 1 and the polymerizable group represented by U 2 may be different from each other, but are preferably the same type of group. Also, the polymerizable group may be in a polymerized state or an unpolymerized state, but is preferably in an unpolymerized state.

[0078] V 1 and V 2Examples of the alkanediyl group represented by V include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,14-diyl group, an icosane-1,20-diyl group, and the like. 1 and V 2 is preferably an alkanediyl group having 2 to 12 carbon atoms, more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0079] Examples of the substituent optionally possessed by the alkanediyl group include a cyano group and a halogen atom. However, the alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted linear alkanediyl group.

[0080] W 1 and W 2 are each independently preferably a single bond, -O-, -S-, -COO- or -OCOO-, more preferably a single bond or -O-.

[0081] The polymerizable liquid crystal compound (A) is not particularly limited as long as it is a polymerizable liquid crystal compound having at least one polymerizable group, and known polymerizable liquid crystal compounds can be used. However, it preferably exhibits smectic liquid crystallinity. As a structure that easily exhibits smectic liquid crystallinity, it preferably has an asymmetric molecular structure in the molecular structure. Specifically, it is more preferably a polymerizable liquid crystal compound having the following partial structures (A-a) to (A-i) and exhibiting smectic liquid crystallinity. From the viewpoint of easily exhibiting higher-order smectic liquid crystallinity, it is more preferably a polymerizable liquid crystal compound having the partial structure of (A-a), (A-b) or (A-c). In the following (A-a) to (A-i), * represents a bond (single bond).

[0082]

Chemical formula

[0083] As the polymerizable liquid crystal compound (A), specifically, for example, compounds represented by formula (A-1) to formula (A-25) can be mentioned. When the polymerizable liquid crystal compound (A) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans form.

[0084]

Chemical formula

[0085]

Chemical formula

[0086]

Chemical formula

[0087]

Chemical formula

[0088]

Chemical formula

[0089] Among these, at least one selected from the group consisting of compounds represented by formula (A-2), formula (A-3), formula (A-4), formula (A-5), formula (A-6), formula (A-7), formula (A-8), formula (A-13), formula (A-14), formula (A-15), formula (A-16) and formula (A-17) is preferable. As the polymerizable liquid crystal compound (A), one kind may be used alone, or two or more kinds may be used in combination.

[0090] The polymerizable liquid crystal 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.

[0091] In the present invention, the polymerizable liquid crystal composition (A) may contain other polymerizable liquid crystal compounds in addition to the polymerizable liquid crystal compound (A). However, from the viewpoint of obtaining a polarizing film with a high degree of orientation order, the ratio of the polymerizable liquid crystal compound (A) to the total mass of all the polymerizable liquid crystal compounds contained in the polymerizable liquid crystal composition (A) is preferably 51% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more.

[0092] When the polymerizable liquid crystal composition (A) contains two or more types of polymerizable liquid crystal compounds (A), at least one of them may be the polymerizable liquid crystal compound (A1), or all of them may be the polymerizable liquid crystal compound (A1). By combining a plurality of polymerizable liquid crystal compounds, it may be possible to temporarily maintain liquid crystallinity even at a temperature below the liquid crystal-crystalline phase transition temperature.

[0093] The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition (A) is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass, and still more preferably 70 to 99% by mass with respect to the solid content of the polymerizable liquid crystal composition (A). When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. In the present specification, the solid content means the total amount of the components obtained by removing the solvent from the polymerizable liquid crystal composition (A).

[0094] In the present invention, the polymerizable liquid crystal composition (A) capable of forming a polarizing layer contains a dichroic dye. Here, the dichroic dye means 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. The dichroic dye that can be used in the present invention is not particularly limited as long as it has the above property, and may be a dye or a pigment. Also, two or more dyes or pigments may be used in combination, or a dye and a pigment may be used in combination.

[0095] As the dichroic dye, the maximum absorption wavelength (λ) is in the range of 300 to 700 nm MAXPreferably, it has []. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, anthraquinone dyes, and the like.

[0096] Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, stilbene azo dyes, etc. Bisazo dyes and trisazo dyes are preferred. For example, a compound represented by the formula (I) (hereinafter, also referred to as "compound (I)") can be mentioned. K 1 (-N=N-K 2 ) p -N=N-K 3 (I) [In the formula (I), K 1 and K 3 each independently represent a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. K 2 represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents an integer of 1 to 4. When p is an integer of 2 or more, a plurality of K 2 may be the same as or different from each other. In the range showing absorption in the visible region, the -N=N- bond may be replaced by a -C=C-, -COO-, -NHCO-, -N=CH- bond.]

[0097] Examples of the monovalent heterocyclic group include groups obtained by removing one hydrogen atom from heterocyclic compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, benzoxazole, etc. Examples of the divalent heterocyclic group include groups obtained by removing two hydrogen atoms from the said heterocyclic compounds.

[0098] K 1 and K 3 The phenyl group, naphthyl group and monovalent heterocyclic group in, and K 2Examples of the substituents that the p-phenylene group, naphthalene-1,4-diyl group, and divalent heterocyclic group may optionally have include an alkyl group having 1 to 4 carbon atoms; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, or a butoxy group; an alkyl fluoride group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; a nitro group; a halogen atom; a substituted or unsubstituted amino group such as an amino group, a diethylamino group, or a pyrrolidino group (a substituted amino group means an amino group having one or two alkyl groups having 1 to 6 carbon atoms, or an amino group in which two substituted alkyl groups are bonded to each other to form an alkanediyl group having 2 to 8 carbon atoms. An unsubstituted amino group is -NH 2 is.).)

[0099] Among the compounds (I), compounds represented by any of the following formulas (I-1) to (I-8) are preferred. [Chemical formula] [In formulas (I-1) to (I-8), B 1 ~B 30 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, a substituted or unsubstituted amino group (the definitions of the substituted amino group and the unsubstituted amino group are as described above), a chlorine atom, or a trifluoromethyl group. 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 as or different from each other, When n2 is 2 or more, the plurality of B 6 may be the same as or different from each other, When n3 is 2 or more, the plurality of B 9 may be the same as or different from each other, When n4 is 2 or more, the plurality of B 14 may be the same as or different from each other.)]

[0100] As the anthraquinone dye, a compound represented by formula (I-9) is preferred. [Chemical formula] [In formula (I-9), R 1 ~R 8 each independently represents 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.]

[0101] As the oxazone dye, a compound represented by formula (I-10) is preferable. [Chemical formula] [In formula (I-10), R 9 ~R 15 each independently represents 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.]

[0102] As the acridine dye, a compound represented by formula (I-11) is preferable. [Chemical formula] [In formula (I-11), R 16 ~R 23 each independently represents a hydrogen atom, -R x , -NH 2 , -NHR x , -NR x 2 , -SR x or a halogen atom. R x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. In formula (I-9), formula (I-10) and formula (I-11), R x Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group, etc. Examples of the aryl group having 6 to 12 carbon atoms include phenyl group, toluyl group, xylyl group and naphthyl group, etc.

[0103] As the cyanine dye, the compound represented by formula (I-12) and the compound represented by formula (I-13) are preferable.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0104] The content (total amount in the case of multiple types) of the dichroic dye in the chiral nematic liquid crystal composition (A) can be appropriately determined according to the type of the dichroic dye used, etc., but is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and still more preferably 0.1 to 12 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the dichroic dye is within the above range, it is difficult to disturb the alignment of the polymerizable liquid crystal compound, and a polarizer having a high degree of alignment order can be obtained.

[0105] In the present invention, the polymerizable liquid crystal composition (A) for forming a polarizer may contain a polymerization initiator. The polymerization initiator is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound, and a photopolymerization initiator is preferable in that it can initiate the polymerization reaction under lower temperature conditions. Specifically, examples of the photopolymerization initiator that can generate an active radical or an acid by the action of light include a photopolymerization initiator that generates a radical by the action of light, and among them, a photopolymerization initiator that generates a radical by the action of light is preferable. The polymerization initiator can be used alone or in combination of two or more.

[0106] As the photopolymerization initiator, known photopolymerization initiators can be used. For example, as the photopolymerization initiator that generates an active radical, there are a self-cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator. As the self-cleavage type photopolymerization initiator, self-cleavage type benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc. can be used. Further, as the hydrogen abstraction type photopolymerization initiator, hydrogen abstraction type benzophenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzosuberone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, halogenoacetophenone compounds, dialkoxyacetophenone compounds, halogenobisimidazole compounds, halogenotriazine compounds, triazine compounds, etc. can be used.

[0107] As the photopolymerization initiator that generates an acid, iodonium salts, sulfonium salts, etc. can be used.

[0108] Among these, from the viewpoint of preventing the dissolution of the dye, a reaction at a low temperature is preferable, and from the viewpoint of the reaction efficiency at a low temperature, a self-cleaving type photoinitiator is preferable, and particularly, an acetophenone-based compound, a hydroxyacetophenone-based compound, an α-aminoacetophenone-based compound, and an oxime ester-based compound are preferable.

[0109] Specific examples of the photoinitiator include the following. Benzoin-based compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; Hydroxyacetophenone-based compounds such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one; α-Aminoacetophenone-based compounds such as 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one and 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one; Oxime ester-based compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)] and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetoxyoxime); Acylphosphine oxide-based compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; Benzophenone compounds such as benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone; Dialkoxyacetophenone compounds such as diethoxyacetophenone; Triazine compounds such as 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine, and 2,4-bis(trichloromethyl)-6-[2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine; The photopolymerization initiator may be appropriately selected, for example, from the above photopolymerization initiators in relation to the polymerizable liquid crystal compound contained in the polymerizable liquid crystal composition (A).

[0110] Alternatively, a commercially available photoinitiator may be used. Examples of commercially available polymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, and 369, 379, 127, 754, OXE01, OXE02, OXE03 (manufactured by BASF); Omnirad BCIM, Esacure 1001M, Esacure KIP160 (manufactured by IDM Resins B.V.); Seikol (registered trademark) BZ, Z, and BEE (manufactured by Seiko Chemical Co., Ltd.); Kayacure (registered trademark) BP100, and UVI-6992 (manufactured by The Dow Chemical Company); Adeka Optomer SP-152, N-1717, N-1919, SP-170, Adeka Arcles NCI-831, Adeka Arcles NCI-930 (manufactured by Adeka Corporation); TAZ-A, and TAZ-PP (manufactured by Nippon Cybenetics Co., Ltd.); and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.); and the like.

[0111] The content of the photoinitiator in the polymerizable liquid crystal composition (A) for forming a polarizer is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. When the content of the photoinitiator is within the above upper and lower limit values, the polymerization reaction of the polymerizable liquid crystal compound can be carried out without significantly disturbing the alignment of the polymerizable liquid crystal compound.

[0112] The polymerizable liquid crystal composition (A) may further contain a photosensitizer. By using a photosensitizer, the polymerization reaction of the polymerizable liquid crystal compound can be further promoted. Examples of the photosensitizer include xanthone compounds such as xanthone and thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene compounds such as anthracene and alkoxy group-containing anthracene (e.g., dibutoxyanthracene, etc.); phenothiazine, rubrene, and the like. The photosensitizer can be used alone or in combination of two or more.

[0113] When the polymerizable liquid crystal composition (A) contains a photosensitizer, its content may be appropriately determined according to the types and amounts of the polymerization initiator and the polymerizable liquid crystal compound. However, with respect to 100 parts by mass of the polymerizable liquid crystal compound, 0.1 to 10 parts by mass is preferable, 0.5 to 5 parts by mass is more preferable, and 0.5 to 3 parts by mass is even more preferable.

[0114] The polymerizable liquid crystal composition (A) may contain a leveling agent. The leveling agent has a function of adjusting the fluidity of the polymerizable liquid crystal composition and making the coating film obtained by applying the polymerizable liquid crystal composition flatter. Specifically, surfactants are exemplified. As the leveling agent, at least one selected from the group consisting of a leveling agent mainly composed of a polyacrylate compound and a leveling agent mainly composed of a fluorine atom-containing compound is preferable. The leveling agent can be used alone or in combination of two or more.

[0115] Examples of the leveling agent mainly composed of a polyacrylate compound include "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", "BYK-358N", "BYK-361N", "BYK-380", "BYK-381", and "BYK-392" (BYK Chemie).

[0116] Examples of the leveling agent mainly composed of a fluorine atom-containing compound include "Megafac (registered trademark) R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", "F-482", and "F-483" (DIC Corporation); "Surflon (registered trademark) S-381", "S-382", "S-383", "S-393", "SC-101", "SC-105", "KH-40", and "SA-100" (AGC Seimi Chemical Co., Ltd.); "E1830" and "E5844" (Daikin Fine Chemical Research Institute Co., Ltd.); and "F-Top EF301", "F-Top EF303", "F-Top EF351", and "F-Top EF352" (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

[0117] When the polymerizable liquid crystal composition (A) contains a leveling agent, the content is preferably 0.05 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the polymerizable liquid crystal compound. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound, and unevenness is less likely to occur, and there is a tendency to obtain a smoother polarizer.

[0118] The polymerizable liquid crystal composition (A) may contain a polymerization inhibitor from the viewpoint of allowing the polymerization reaction to proceed stably. The polymerization inhibitor can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound. Examples of the polymerization inhibitor include radical scavengers such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (e.g., butylcatechol, etc.), pyrogallol, 2,2,6,6-tetramethyl-1-piperidinyloxy radical; thiophenols; β-naphthylamines or β-naphthols.

[0119] When the polymerizable liquid crystal composition (A) 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, and still more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the content of the polymerizable liquid crystal compound. When the content of the polymerization inhibitor is within the above range, polymerization can be carried out without significantly disturbing the alignment of the polymerizable liquid crystal compound.

[0120] Furthermore, the polymerizable liquid crystal composition (A) may contain a reactive additive. As the reactive additive, those having a carbon-carbon unsaturated bond and an active hydrogen-reactive group in its molecule are preferred. Here, the "active hydrogen-reactive group" means a group reactive with a group having active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amino group (-NH 2 ) etc., and typical examples thereof include a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, a maleic anhydride group, etc. The number of carbon-carbon unsaturated bonds or active hydrogen-reactive groups possessed by the reactive additive is usually 1 to 20 each, preferably 1 to 10 each.

[0121] In the reactive additive, it is preferable that at least two active hydrogen-reactive groups are present. In this case, the plurality of active hydrogen-reactive groups may be the same or different.

[0122] The carbon-carbon unsaturated bond possessed by the reactive additive may be a carbon-carbon double bond, a carbon-carbon triple bond, or a combination thereof, but a carbon-carbon double bond is preferred. Among them, as the reactive additive, it is preferable to contain a carbon-carbon unsaturated bond as a vinyl group and / or a (meth)acrylic group. Furthermore, a reactive additive in which the active hydrogen-reactive group is at least one selected from the group consisting of an epoxy group, a glycidyl group, and an isocyanate group is preferred, and a reactive additive having an acrylic group and an isocyanate group is more preferred.

[0123] Specific examples of the reactive additive include compounds having a (meth)acrylic group and an epoxy group, such as glycidyl methacrylate and glycidyl acrylate; compounds having a (meth)acrylic group and an oxetane group, such as oxetane acrylate and oxetane methacrylate; compounds having a (meth)acrylic group and a lactone group, such as lactone acrylate and lactone methacrylate; compounds having a vinyl group and an oxazoline group, such as vinyl oxazoline and isopropenyl oxazoline; oligomers of compounds having a (meth)acrylic group and an isocyanate group, such as isocyanatomethyl acrylate, isocyanatomethyl methacrylate, 2-isocyanatoethyl acrylate or 2-isocyanatoethyl methacrylate. Further, compounds having a vinyl group or a vinylene group and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride or maleic anhydride vinyl are also included. Among them, glycidyl methacrylate, glycidyl acrylate, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyl oxazoline, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate or the above oligomers are preferred, and isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate or the above oligomers are particularly preferred.

[0124] Specifically, a compound represented by the following formula (Y) is preferred.

[0125] [Chemical formula]

[0126] [In formula (Y), n represents an integer from 1 to 10, and R 1’ represents a divalent aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 5 to 20 carbon atoms. Two R 2’ in each repeating unit are such that one is -NH- and the other is a group represented by >N-C(=O)-R 3’ . R 3’ represents a hydroxyl group or a group having a carbon-carbon unsaturated bond. R in formula (Y) 3’ Among them, at least one R 3’ is a group having a carbon-carbon unsaturated bond.

[0127] Among the reactive additives represented by the above formula (Y), a compound represented by the following formula (YY) (hereinafter sometimes referred to as compound (YY)) is particularly preferable (where n has the same meaning as above).

[0128]

Chemical formula

[0129] As the compound (YY), commercially available products can be used as they are or purified as necessary. Examples of commercially available products include Laromer (registered trademark) LR-9000 (manufactured by BASF).

[0130] When the polymerizable liquid crystal composition (A) contains a reactive additive, the content of the reactive additive is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the liquid crystal compound.

[0131] The polymerizable liquid crystal composition (A) may contain a photosensitizer, a leveling agent, a polymerization inhibitor, and other additives other than the reactive additive. Examples of other additives include release agents, stabilizers, colorants such as bluing agents, flame retardants, and lubricants. When the polymerizable liquid crystal composition (A) contains other additives, the content of the other additives is preferably more than 0% and 20% by mass or less, more preferably more than 0% and 10% by mass or less, based on the solid content of the polymerizable liquid crystal composition (A).

[0132] The polymerizable liquid crystal composition (A) can be produced by a conventionally known production method, and is usually prepared by mixing and stirring a polymerizable liquid crystal compound, a dichroic dye, and, if necessary, a polymerization initiator and the above-mentioned additives, etc.

[0133] The polarizing layer constituting the polarizing film of the present invention can be formed from a polymerizable liquid crystal composition (A) by a method including, for example: forming a coating film of the polymerizable liquid crystal composition (A); removing the solvent from the coating film; heating the polymerizable liquid crystal compound to a temperature equal to or higher than the temperature at which the polymerizable liquid crystal compound undergoes a phase transition to a liquid crystal phase and then cooling it to cause the polymerizable liquid crystal compound to undergo a phase transition; and polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal phase. The formation of the coating film of the polymerizable liquid crystal composition (A) can be carried out, for example, by applying the polymerizable liquid crystal composition (A) directly onto the substrate described above or through an alignment film described later. At this time, in particular, since compounds generally exhibiting smectic liquid crystallinity have a high viscosity, from the viewpoint of improving the coatability of the polymerizable liquid crystal composition (A) and facilitating the formation of a polarizer, the viscosity may be adjusted by adding a solvent to the polymerizable liquid crystal composition (A) (hereinafter, the composition obtained by adding a solvent to the polymerizable liquid crystal composition is also referred to as a "composition for forming a polarizing layer").

[0134]

[0135] ​The solvent used in the composition for forming a polarizing layer can be appropriately selected according to the solubility of the polymerizable liquid crystal compound and dichroic dye to be used, etc. Specifically, for example, water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, alcohol solvents such as propylene glycol monomethyl ether, ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate, ester solvents such as ethyl lactate, acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, ketone solvents such as methyl isobutyl ketone, pentane, hexane, aliphatic hydrocarbon solvents such as heptane, toluene, aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile, tetrahydrofuran, ether solvents such as dimethoxyethane, and chlorinated hydrocarbon solvents such as chloroform and chlorobenzene, etc. can be mentioned. These solvents can be used alone or in combination of two or more.

[0136] The content of the solvent is preferably 100 to 1900 parts by mass, more preferably 150 to 900 parts by mass, and still more preferably 180 to 600 parts by mass with respect to 100 parts by mass of the solid content constituting the polymerizable liquid crystal composition (A).

[0137] As a method for applying the composition for forming a polarizing layer to a substrate or the like, known methods such as spin coating method, extrusion method, gravure coating method, die coating method, bar coating method, applicator method and other coating methods, and printing methods such as flexo method can be mentioned.

[0138] Next, under the condition that the polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing layer does not polymerize, the solvent is removed by drying or the like to form a dried coating film. Examples of the drying method include natural drying method, ventilation drying method, heat drying and vacuum drying method, etc.

[0139] Furthermore, in order to cause the polymerizable liquid crystal compound to undergo a phase transition into a liquid crystal phase, the temperature is raised to a temperature equal to or higher than the temperature at which the polymerizable liquid crystal compound undergoes a phase transition into the liquid crystal phase and then lowered to cause the polymerizable liquid crystal compound to undergo a phase transition into a liquid crystal phase (smectic phase). Such a phase transition may be carried out after removing the solvent in the coating film, or may be carried out simultaneously with the removal of the solvent.

[0140] While maintaining the (smectic) liquid crystal state of the polymerizable liquid crystal compound, the polymerizable liquid crystal compound is polymerized to form a polarizer as a cured layer of the polymerizable liquid crystal composition. As the polymerization method, a photopolymerization method is preferred. In photopolymerization, the light irradiated on the dry coating film is appropriately selected according to the type of the polymerizable liquid crystal compound contained in the dry coating film (particularly, the type of the polymerizable group possessed by the polymerizable liquid crystal compound), the type of the polymerization initiator, and their amounts. Specific examples thereof include one or more types of active energy rays and electron beams selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays. Among them, ultraviolet light is preferred in terms of being easy to control the progress of the polymerization reaction and being able to use a widely used photopolymerization apparatus in the art. It is preferable to select the types of the polymerizable liquid crystal compound and the polymerization initiator contained in the polymerizable liquid crystal composition so that photopolymerization can be carried out by ultraviolet light. Further, during polymerization, the polymerization temperature can also be controlled by irradiating light while cooling the dry coating film by an appropriate cooling means. By adopting such a cooling means, if the polymerization of the polymerizable liquid crystal compound is carried out at a lower temperature, a polarizer can be appropriately formed even when a substrate with relatively low heat resistance is used. During photopolymerization, a patterned polarizer can also be obtained by performing masking, development, etc.

[0141] Examples of the light source for the active energy rays include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, an LED light source emitting in a wavelength range of 380 to 440 nm, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, etc.

[0142] The ultraviolet irradiation intensity is usually 10 to 3,000 mW / cm 2 . The ultraviolet irradiation intensity is preferably the intensity in the wavelength region effective for activating the polymerization initiator. The time for irradiating light is usually 0.1 second to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, and even more preferably 10 seconds to 1 minute. When irradiated once or a plurality of times with such an ultraviolet irradiation intensity, the integrated light amount is 10 to 3,000 mJ / cm 2 , preferably 50 to 2,000 mJ / cm 2 , more preferably 100 to 1,000 mJ / cm 2 .

[0143] By performing photopolymerization, the polymerizable liquid crystal compound preferably polymerizes while maintaining a liquid crystal state of a smectic phase, preferably a higher-order smectic phase, and a polarizing layer is formed. The polarizing layer obtained by polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal state of the smectic phase has an advantage of high polarization performance also due to the action of the dichroic dye. Further, there is also an advantage of excellent strength as compared with a case where only a dichroic dye or a lyotropic liquid crystal is applied.

[0144] The thickness of the polarizing layer formed from the composition for forming a polarizing layer can be appropriately selected according to the use of the polarizing film and the display device to which it is applied. It is preferably a film of 0.1 μm or more and 5 μm or less, more preferably 0.3 μm or more and 4 μm or less, and even more preferably 0.5 μm or more and 3 μm or less.

[0145] In the present invention, the polarizing layer formed from the composition for forming a polarizing layer may be laminated (formed) on the substrate surface via an alignment layer. The alignment layer has an alignment regulating force for aligning the polymerizable liquid crystal compound in a desired direction. By including the alignment layer, it becomes easier to improve the alignment accuracy of the polymerizable liquid crystal compound. Therefore, in one aspect of the present invention, the polarizing film has an alignment layer between the polarizing layer and the substrate layer. As the alignment layer, those having solvent resistance that do not dissolve in the composition containing the polymerizable liquid crystal compound by coating or the like, and also having heat resistance in heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound are preferable. In the present invention, examples of the alignment layer include an alignment film containing an alignment polymer, a photo-alignment film, a groove alignment film having an uneven pattern or a plurality of grooves on the surface, a stretched film stretched in the alignment direction, etc. From the viewpoints of the accuracy and quality of the alignment angle, and the water resistance and flexibility of the polarizing film including the alignment layer, a photo-alignment film is preferable. The photo-alignment film is also advantageous in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

[0146] Examples of the alignment polymer include polyamides having an amide bond in the molecule and gelatins, polyimides having an imide bond in the molecule and polyamic acids which are hydrolysis products thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters. Among them, polyvinyl alcohol is preferable. The alignment polymer can be used alone or in combination of two or more.

[0147] The alignment film containing an alignment polymer is usually obtained by applying a composition in which the alignment polymer is dissolved in a solvent (hereinafter also referred to as "alignment polymer composition") to a substrate and removing the solvent, or by applying the alignment polymer composition to a substrate, removing the solvent, and rubbing (rubbing method). Examples of the solvent include the same solvents as those exemplified above as solvents that can be used in the composition for forming a polarizing layer.

[0148] The concentration of the alignment polymer in the alignment polymer composition may be within the range where the alignment polymer material can be completely dissolved in the solvent, but preferably 0.1 to 20% in terms of solid content with respect to the solution, and more preferably about 0.1 to 10%.

[0149] As the alignment polymer composition, a commercially available alignment film material may be used as it is. Examples of the commercially available alignment film materials include Sunever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optomer (registered trademark, manufactured by JSR Corporation), and the like.

[0150] As a method for applying the alignment polymer composition to a substrate, the same methods as those exemplified above as methods for applying the composition for forming a polarization layer to a substrate can be mentioned.

[0151] As methods for removing the solvent contained in the alignment polymer composition, a natural drying method, a ventilation drying method, a heat drying method, a reduced pressure drying method, and the like can be mentioned.

[0152] In order to impart an alignment regulating force to the alignment film, a rubbing treatment can be performed as necessary (rubbing method). As a method for imparting an alignment regulating force by the rubbing method, a method of bringing the film of the alignment polymer formed on the substrate surface into contact with a rubbing roll on which a rubbing cloth is wound and rotated by applying the alignment polymer composition to the substrate and annealing it can be mentioned. When performing the rubbing treatment, if masking is performed, a plurality of regions (patterns) having different alignment directions can also be formed on the alignment film.

[0153] The photo-alignment film is usually obtained by applying a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter also referred to as "composition for forming a photo-alignment film") to a substrate and irradiating it with polarized light (preferably polarized UV).

[0154] The photoreactive group refers to a group that generates liquid crystal alignment ability upon light irradiation. Specifically, it includes groups involved in photoreactions that are the origin of liquid crystal alignment ability, such as the orientation induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photodegradation reaction of molecules generated by light irradiation. Among them, groups involved in the dimerization reaction or photocrosslinking reaction are preferred in terms of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond, is preferred, and a group having at least one selected from the group consisting of a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond) is particularly preferred.

[0155] Examples of the photoreactive group having a C=C bond include a vinyl group, a polyene group, a stilbene group, a stilbazoyl group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C=N bond include groups having structures such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C=O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents 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, and a halogenated alkyl group.

[0156] Among them, the photoreactive group involved in the photodimerization reaction is preferred, and the cinnamoyl group and the chalcone group are preferred in that a relatively small amount of polarized light irradiation required for photoalignment is needed, and a photoalignment film excellent in thermal stability and stability over time can be easily obtained. As the polymer having a photoreactive group, a polymer having a cinnamoyl group such that the terminal portion of the side chain of the polymer has a cinnamic acid structure is particularly preferred.

[0157] By applying the composition for forming an optically aligned film onto a substrate, an optically alignment-inducing layer can be formed on the substrate. Examples of the solvent contained in the composition include the same solvents as those exemplified above that can be used in the composition for forming a polarization layer, and can be appropriately selected according to the solubility of the polymer or monomer having a photoreactive group.

[0158] The content of the polymer or monomer having a photoreactive group in the composition for forming an optically aligned film can be appropriately adjusted according to the type of the polymer or monomer and the thickness of the intended optically aligned film. However, it is preferably at least 0.2% by mass, more preferably in the range of 0.3 to 10% by mass, based on the mass of the composition for forming an optically aligned film. The composition for forming an optically aligned film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer, as long as the properties of the optically aligned film are not significantly impaired.

[0159] Examples of the method for applying the composition for forming an optically aligned film onto a substrate and the method for removing the solvent from the applied composition for forming an optically aligned film include the same methods as those for applying the composition for forming a polarization layer onto a substrate and removing the solvent.

[0160] The polarized light irradiation may be in a form where the solvent is removed from the composition for forming an optically oriented film applied on the substrate and then directly irradiated with polarized UV light, or in a form where the polarized light is irradiated from the substrate side and transmitted through the polarized light for irradiation. Further, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength region where the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) in the range of 250 to 400 nm in wavelength is particularly preferable. Examples of the light source used for the polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are more preferable. Among these, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are preferable because they have a high emission intensity of ultraviolet light with a wavelength of 313 nm. By passing the light from the light source through an appropriate polarizer and irradiating, polarized UV light can be irradiated. As such a polarizer, a polarizing filter, a polarizing prism such as a Glan-Thomson or Glan-Taylor, or a wire grid type polarizer can be used.

[0161] In addition, when rubbing or polarized light irradiation is performed, masking can be performed to form a plurality of regions (patterns) with different liquid crystal alignment directions.

[0162] A groove alignment film is a film having an uneven pattern or a plurality of grooves on the film surface. When a polymerizable liquid crystal compound is applied to a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction along the grooves.

[0163] As a method for obtaining a grooved alignment film, there are a method of forming a concavo-convex pattern by performing exposure, development, and rinsing processes after exposure through an exposure mask having a slit in a pattern shape on the surface of a photosensitive polyimide film; a method of forming a layer of a UV-curable resin before curing on a plate-shaped master having grooves on its surface, transferring the formed resin layer to a substrate, and then curing it; and a method of pressing a roll-shaped master having a plurality of grooves against a film of a UV-curable resin before curing formed on a substrate to form irregularities, and then curing it.

[0164] The thickness of the alignment layer (an alignment film or a photo-alignment film containing an alignment polymer) is usually 10 to 5000 nm, preferably 10 to 1000 nm, more preferably 10 to 500 nm, still more preferably 10 to 300 nm, and particularly preferably 30 to 300 nm.

[0165] In this way, a laminated film including a polarizing layer composed of a cured layer of a composition for forming a polarizing layer, laminated on a substrate via an alignment layer as necessary, can be obtained.

[0166] In addition to the substrate layer, the polarizing layer, and, if necessary, the alignment layer, the polarizing film of the present invention may include other layers that a conventional polarizing film may contain. Examples of such other layers include a protective layer for protecting the polarizing layer.

[0167] <Method for manufacturing a polarizing film> The polarizing film of the present invention can be manufactured, for example, by a method including a step of forming a region having a first visual sensitivity correction single transmittance (hereinafter, also referred to as "first region forming step"), and a step of forming, adjacent to the region having the first visual sensitivity correction single transmittance, a region having a transmittance higher than the first visual sensitivity correction single transmittance and a difference from the first visual sensitivity correction single transmittance of less than 30% and a visual sensitivity correction degree of polarization of more than 10% (hereinafter, also referred to as "second region forming step"). and can be manufactured by a method including these steps. Hereinafter, an example of the method for manufacturing the polarizing film of the present invention will be described with reference to FIGS. 10 and 11.

[0168] The region having the first single transmittance for visual sensitivity correction is the region having the first single transmittance for visual sensitivity correction in the polarizing film of the present invention, and the first region forming step is usually a step of forming a polarizing layer. The polarizing layer can be produced according to the methods exemplified above depending on its type, such as being composed of a stretched film adsorbed with a dichroic dye or being a cured layer of a composition for forming a polarizing layer. Thus, a laminated film (14) including a polarizing layer (13) having a substantially uniform first single transmittance for visual sensitivity correction is obtained on a substrate layer (12) as shown in FIG. 10.

[0169] The region that is higher than the first single transmittance for visual sensitivity correction, has a difference from the first single transmittance for visual sensitivity correction of less than 30%, and has a visual sensitivity correction degree of polarization greater than 10% corresponds to the region X included in the second region in the polarizing film of the present invention. In the production of the polarizing film of the present invention, the first region and the second region may be produced as completely separate steps. However, from the viewpoints of ease of production, production efficiency, and optical characteristics of the obtained polarizing film, etc., after forming a polarizing layer having the first single transmittance for visual sensitivity correction over the entire region that will finally become the first region or the second region, it is preferable to form the second region in the desired region.

[0170] The second region forming step is, for example, In the laminated film obtained by the first region forming step, laminating a protective film having a coating region for covering the region that will finally become the first region and an exposure region for exposing the region that will finally become the second region on the laminated film (hereinafter, also referred to as the "protective film laminating step"), Contacting the laminated film with the protective film with a dissolving solution capable of eluting a part of the dye of the polarizing layer formed in the first region forming step, so that the visual sensitivity correction single transmittance of the polarizing layer existing in the exposure region is higher in the range of less than 30% than the first visual sensitivity correction single transmittance, and eluting a part of the dye of the polarizing layer in the exposure region so that the visual sensitivity correction degree of polarization becomes greater than 10% (hereinafter, also referred to as the "dissolving solution contacting step") can be carried out by a method including these steps.

[0171] In the protective film laminating step, as shown in FIG. 10, on the polarizing layer (13) of the laminated film obtained in the first region forming step, a protective film (20) having a covering region (21) for covering the region that will finally become the first region and an exposure region (22) for exposing the region that will finally become the second region is laminated on the laminated film (14). Thereby, a laminated film (15) with a protective film can be obtained. The exposure region (22) can be, for example, an opening of the protective film (20). The covering region (21) is a region for preventing the dissolving solution from coming into contact with the polarizing layer (13) when the dissolving solution capable of dissolving a part of the dyes in the polarizing layer (13) described later is brought into contact with the laminated film (15) with the protective film. On the other hand, in the exposure region (22) of the protective film (20), the dissolving solution can be brought into contact with the polarizing layer (13).

[0172] When the polarizing layer (13) comes into contact with the dissolving solution, the dissolving solution elutes a part of the dyes in the polarizing layer (13). By controlling the degree of this elution, the visual sensitivity correction single transmittance and the visual sensitivity correction polarization degree of the polarizing layer (13) can be adjusted. Therefore, the exposure region (22) is preferably formed corresponding to the region that will finally become the second region. For example, when manufacturing the polarizing film (11) shown in FIG. 2, it is preferable to determine its shape according to the shape of the second region (2), and it may be formed corresponding to the planar shape of the second region (2). Considering that the dissolving solution penetrates into the polarizing layer, the exposure region (22) may be formed slightly smaller than the finally desired second region (2).

[0173] Also, the covering region (21) of the protective film (20) is preferably formed corresponding to the region that does not elute a part of the dyes in the polarizing layer (13). For example, when manufacturing the polarizing film (11) shown in FIG. 2, it is preferable to determine its shape according to the shape of the first region (1).

[0174] As the protective film (20), one obtained by forming an area to be an exposed area (22) on a sheet-like base material can be used. The area to be the exposed area (22) can be formed by mechanically punching out a predetermined portion of the sheet-like base material by means such as punching, a cutting plotter, or a water jet, or by removing a predetermined portion of the sheet-like base material by means such as laser ablation or chemical dissolution.

[0175] As the sheet-like base material for forming the protective film (20), as long as it is insoluble in a solution capable of eluting a part of the dye of the polarizing layer (13) when brought into contact with the solution and has durability under the cleaning conditions for removing the solution and the eluted part of the dye, the material thereof is not particularly limited. As the sheet-like base material for forming the protective film (20), for example, the same material as the above-described base material layer can be used, and it is particularly preferably formed using a resin base material. It is more preferable to use a polyester resin such as polyethylene terephthalate that is likely to suppress deformation of the area (for example, the opening) that becomes the exposed area (22) of the protective film (20).

[0176] The protective film (20) preferably has an adhesive layer (not shown) for bonding to the polarizing layer (13). Since the protective film (20) is to be peeled off later, the adhesive layer is preferably peelable from the polarizing layer (13). The thickness of the protective film (20) is usually 20 μm or more, preferably 30 μm or more, and usually 250 μm or less, preferably 200 μm or less.

[0177] In the solution contact step, by bringing the laminated film (15) with the protective film into contact with a solution capable of eluting a part of the dye of the polarizing layer (13), the single transmittance of visual sensitivity correction and the polarization degree of visual sensitivity correction of the polarizing layer (13) present in the exposed area (22) are adjusted to desired values, and a polarizing film including at least two areas having different single transmittances of visual sensitivity correction in the plane direction can be obtained.

[0178] The contact between the laminated film (15) with the protective film and the dissolving solution can be carried out by immersing the laminated film (15) with the protective film in the dissolving solution, applying, spraying, dropping the dissolving solution onto the laminated film (15) with the protective film, etc., and it is preferably carried out by the method of immersing the laminated film (15) with the protective film in the dissolving solution. Thereby, in the polarizing layer (13), the dissolving solution contacts the surface of the polarizing layer (13) exposed from the exposed region (22) of the protective film (20), and a part of the dye in the polarizing layer (13) within the exposed region (22) elutes. By controlling the amount / degree of elution of the dye, the single transmittance with visual sensitivity correction and the polarization degree with visual sensitivity correction of the polarizing layer (13) in the exposed region (22) can be controlled. Generally, the larger the amount of the eluted and removed dye, the higher the single transmittance with visual sensitivity correction in the region, and the lower the polarization degree with visual sensitivity correction tends to be. Regarding the amount and degree of the eluted dye, in relation to the material constituting the polarizing layer, it can be controlled by selecting / adjusting the type of the dissolving solution, the contact time between the polarizing layer and the dissolving solution, the temperature of the dissolving solution, etc., which will be described later.

[0179] Among the surfaces of the polarizing layer (13), the region covered by the covering region (21) of the protective film (20) is such that the dye in the polarizing layer (13) is hardly eluted because the polarizing layer (13) does not directly contact the dissolving solution. Therefore, for example, in FIG. 10, in the region corresponding to the covering region (21) of the polarizing layer (13), the polarizing layer (13) remains, and in the region corresponding to the exposed region (22), a polarizing film can be obtained in which the single transmittance with visual sensitivity correction and the polarization degree with visual sensitivity correction of the polarizing layer (13) are controlled with respect to the covering region (21).

[0180] Since the dissolving solution elutes the dye in the polarizing layer, it is preferable to adjust the thickness of the protective film, the size of the exposed region, the concentration of the dissolving solution, the immersion time of the laminated film with the protective film in the dissolving solution, the coating amount, spraying amount or dropping amount of the dissolving solution onto the laminated film with the protective film, etc., so that the dye in the polarizing layer in the unnecessary region is not eluted and removed.

[0181] The dissolving solution is one that elutes a part of the dye in the polarizing layer, does not dissolve the entire polarizing layer, and does not dissolve the base material layer and the protective film. There is no particular limitation as long as it meets these conditions, but an organic solvent is preferred. 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, ketones such as acetone, methyl ethyl ketone, and cyclopentanone, chlorine-containing substances such as chloroform, and dissolving solutions containing sulfur such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane can be mentioned. These may be used alone or in combination.

[0182] By appropriately selecting these solvents according to the components constituting the polarizing layer, the single transmittance of visual sensitivity correction and the polarization degree of visual sensitivity correction of the polarizing layer in the exposed area can be controlled. For example, for a polarizing layer based on a polyvinyl alcohol-based resin film, it is preferable to use hydrophilic solvents such as water and alcohol. Also, for a polarizing layer that is a cured layer of a composition for forming a polarizing layer containing a dichroic dye and a liquid crystal compound, it is preferable to use solvents such as toluene and dimethyl sulfoxide. When performing the dissolving solution contact step multiple times to form regions having at least two different single transmittances of visual sensitivity correction in the second region, the types of dissolving solutions used in each dissolving solution contact step may be the same or different.

[0183] The contact conditions for bringing the laminated film with a protective layer into contact with the dissolving solution may be appropriately selected according to the thickness of the polarizing layer, the size of the region in contact with the dissolving solution for eluting a part of the dye in the polarizing layer, and the like. The temperature of the dissolving solution is preferably 10 to 80°C, and more preferably 20 to 60°C. The contact time between the laminated film with a protective layer and the dissolving solution may be appropriately adjusted according to the desired single transmittance of visual sensitivity correction and the polarization degree of visual sensitivity correction. The contact time is usually 1 to 300 seconds, and preferably 5 to 120 seconds.

[0184] After the dissolution liquid contact step, it is preferable to provide a cleaning step for washing away the dissolution liquid and the eluted dye. The cleaning step can be carried out, for example, when the polarizing layer is a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound, by appropriately using a solvent such as water or alcohol that does not dissolve the polarizing layer or the dye in the polarizing layer.

[0185] After the dissolution liquid contact step, by peeling the protective film from the laminated film with the protective film (hereinafter, also referred to as the "peeling step"), a polarizing film having a first region and a second region can be obtained.

[0186] In the polarizing film containing two regions having different single transmittances of visual sensitivity correction obtained by the above process, after further laminating different protective films on the exposed regions and then performing a dissolution liquid contact process, a polarizing film can be obtained in which the single transmittance of visual sensitivity correction gradually increases from the outer contour to the inside of the second region. For example, in the laminated film (16) with a protective film shown in FIG. 11, on the polarizing layer (13) having the first region (1) and the second region (2) obtained by the above process, a protective film (25) provided with a coating region (23) and an exposed region (24) different from the protective film (20) used in the above process is laminated. The exposed region (24) of the laminated film (16) with a protective film in FIG. 11 is narrower than the exposed region (22) that contacted the dissolution liquid in the previous process. By bringing the polarizing layer (13) exposed in the exposed region (24) into contact with a dissolution liquid capable of eluting a part of the dye of the polarizing layer, the single transmittance of visual sensitivity correction and the polarized light degree of visual sensitivity correction of the polarizing layer (13) in the exposed region (24) are adjusted to desired values, and a polarizing film having a region where the single transmittance of visual sensitivity correction and the polarized light degree of visual sensitivity correction are further controlled is obtained inside the second region. By repeating such an operation, a polarizing film having, for example, a region 2-1(3) as shown in FIG. 4 and a region 2-2(4) located inside thereof, in which the single transmittance of visual sensitivity correction gradually increases from the outer contour to the inside of the second region, can be obtained. By selecting the number of times of the dissolution liquid contact process, these process conditions, the type of the dissolution liquid, etc., the single transmittance of visual sensitivity correction and the polarized light degree of visual sensitivity correction of the second region are controlled, and a polarizing film having a second region with a pattern represented by FIGS. 2, 4, 6, and 8 can be produced.

[0187] In order to form regions having at least two different single transmittances of visual sensitivity correction in the second region when performing the dissolution liquid contact process a plurality of times, the type of the dissolution liquid used in each dissolution liquid contact process may be the same or different. Further, the contact conditions between the laminated film with a protective film and the dissolution liquid may be appropriately adjusted according to the desired single transmittance of visual sensitivity correction and the polarized light degree of visual sensitivity correction, and the conditions adopted in each dissolution liquid contact process may be the same or different.

[0188] In the present invention, the polarizing film can be continuously manufactured by a Roll to Roll method. In this case, in the first region forming step, a laminated film including a base material layer and a polarizing layer, which is wound in a roll shape, is produced, and while unwinding this laminated film, it is conveyed, and steps such as a protective film laminating step and a dissolution liquid contact step may be continuously performed. In the protective film laminating step, while unwinding the protective film wound in a roll shape and conveying it, the protective film may be laminated on the laminated film to obtain a laminated film with a protective film. In the dissolution liquid contact step, while continuously conveying the laminated film with a protective film, it may be passed through a dissolution liquid bath filled with a dissolution liquid, or while continuously conveying the laminated film with a protective film, the dissolution liquid may be applied, sprayed or dropped to obtain a polarizing film with a protective film having a first region and a second region. Then, while conveying the polarizing film with a protective film, the protective film may be continuously peeled off, and the polarizing film may be wound in a roll shape to form a wound body. When the second region is composed of a plurality of regions having different visual sensitivity correction single transmittances, a polarizing film having a desired pattern can be manufactured by repeating the protective film laminating step, the dissolution liquid contact step and the peeling step. The polarizing film continuously manufactured as described above can have a length of, for example, 10 m or more.

[0189] In the first region forming step, while unwinding and conveying the base material layer wound in a roll shape, the polarizing layer composed of a stretched film is laminated on this base material layer via an adhesive layer or the like, or on the base material layer, a composition for forming a polarizing layer is continuously coated by a coating device, and dried and cured to continuously form a polarizing layer. When the polarizing film includes an alignment layer between the base material layer and the polarizing layer, for example, while unwinding and conveying the base material layer wound in a roll shape, a composition for forming an alignment layer may be continuously coated on this base material layer by a coating device to form an alignment layer.

[0190] <Elliptical polarizing plate> The polarizing film of the present invention can be suitably used as a material for forming an elliptical polarizing plate by laminating it with a retardation film. Therefore, the present invention includes an elliptical polarizing plate including the polarizing film of the present invention and a retardation film.

[0191] Examples of the retardation film include a stretched film that imparts retardation by stretching a polymer, and a cured product of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound, wherein the polymerizable liquid crystal compound is cured in a state oriented in a horizontal or vertical direction with respect to the film surface. From the viewpoint of thinning the resulting elliptical polarizing plate, it is preferable that the retardation film is composed of a cured product of a polymerizable liquid crystal composition. As the polymerizable liquid crystal compound and the polymerizable liquid crystal composition for forming the retardation film, for example, those described in JP-A-2011-207765 and the like can be used.

[0192] The elliptical polarizing plate of the present invention is composed of the polarizing film of the present invention or a polarizing film obtained by removing the base material from the polarizing film of the present invention. For example, the elliptical polarizing plate of the present invention can be obtained by laminating the polarizing film of the present invention and the retardation film via an adhesive layer or the like. Further, the elliptical polarizing plate of the present invention can be obtained by bonding the retardation film to the polarizing film obtained by removing the base material from the polarizing film of the present invention. As the adhesive, known adhesives and / or bonding agents in the art can be used.

[0193] The laminate and the elliptical polarizing plate of the present invention can be used in various display devices. A display device is a device having a display element and includes a light-emitting element or a light-emitting device as a light source. Examples of the display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (e.g., a field emission display device (FED), a surface field emission display device (SED)), an electronic paper (a display device using electronic ink or an electrophoretic element), a plasma display device, a projection display device (e.g., a grating light valve (GLV) display device, a display device having a digital micromirror device (DMD)), and a piezoelectric ceramic display. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection liquid crystal display device. These display devices may be a display device for displaying a two-dimensional image or a stereoscopic display device for displaying a three-dimensional image.

[0194] The polarizing film of the present invention can be a polarizing film in which the entire film exhibits light absorption anisotropy while being a film patterned into regions having different visual sensitivity correction single transmittances. By utilizing such characteristics, for example, the second region can be used as a region corresponding to the lens position of a camera provided in a smartphone, a tablet, etc., and an unprecedented display device can be configured that can display an image even in the camera hole region without disturbing the camera function, and it can be an optical film.

Examples

[0195] The present invention will be described more specifically based on examples. However, the present invention is not limited by these examples. In the examples and comparative examples, “%” and “parts” are mass % and parts by mass, respectively, unless otherwise specified.

[0196] 1. Example 1 (1) Preparation 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, which is a composition for forming an optical alignment film. · Polymer 2 having a photoreactive group represented by the following formula [Chemical formula] [In the above formula, n is 10 to 50.] · Solvent: 98 parts of o-xylene

[0197] (2) Preparation 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, an azo dye described in the examples of JP-A-2013-101328 was used. · 75 parts of a polymerizable liquid crystal compound represented by formula (1-6) [Chemical formula] · 25 parts of a polymerizable liquid crystal compound represented by formula (1-7) [Chemical formula] · 2.8 parts of the dichroic dye (1) shown below [Chemical formula] · 2.8 parts of the dichroic dye (2) shown below [Chemical formula] · 2.8 parts of the dichroic dye (3) shown below [Chemical formula] · Polymerization initiator: 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals) 6 parts · Levelling agent: Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie) 1.2 parts · Solvent: 250 parts of cyclopentanone

[0198] (3) Manufacture of a polarizing film (a) Formation of a polarizing layer having a first visual sensitivity correction single transmittance A triacetyl cellulose film (KC4UY-TAC, thickness 40 μm, manufactured by Konica Minolta) as a base material layer was cut into 20×20 mm pieces, and its surface was subjected to corona treatment (AGF-B10, manufactured by Kasuga Electric Co., Ltd.). After applying a composition for forming an alignment layer onto the surface of the film subjected to corona treatment using a bar coater, it was dried in a drying oven set at 120°C for 1 minute to obtain a coating layer for the alignment layer. Using a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.), polarized UV in the 0° direction with respect to the film edge was irradiated onto the coating layer for the alignment layer with an integrated light quantity of 50 mJ / cm 2 (based on 313 nm) to form an alignment layer. After applying a composition for forming a polarizing layer onto the obtained alignment layer using a bar coater, it was dried in a drying oven set at 110°C for 1 minute. Then, using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.), ultraviolet rays were irradiated (in a nitrogen atmosphere, wavelength: 365 nm, integrated light quantity at wavelength 365 nm: 1000 mJ / cm 2 ) to obtain a polarizing layer in which a liquid crystal compound and a dichroic dye were aligned. For the obtained polarizing film, the visual sensitivity corrected single transmittance (Ty) and the visual sensitivity corrected polarization degree (Py) were measured according to the method described below. The results are shown in Table 1 as the visual sensitivity corrected single transmittance (Ty) and the visual sensitivity corrected polarization degree (Py) in the first region.

[0199] (b) Formation of the second region (region 2-1) A protective film (AY-638 manufactured by Fujimori Kogyo Co., Ltd., composed of an adhesive layer with a thickness of 15 μm on a polyester film with a thickness of 38 μm) having an opening (exposed region) of 5 mm was laminated onto the polarizing layer having the first visual sensitivity corrected single transmittance obtained above. Then, the opening was immersed in toluene at room temperature (25°C) for 60 seconds. Next, after removing the toluene, the protective film was peeled off to obtain a polarizing film 1 having region 2-1. The visual sensitivity corrected single transmittance (Ty) and the visual sensitivity corrected polarization degree (Py) of region 2-1 of the obtained polarizing film 1 were measured according to the method described below. The results are shown in Table 1.

[0200] (c) Formation of the second region (region 2-2) Next, a protective film (AY-638 manufactured by Fujimori Kogyo Co., Ltd., composed of an adhesive layer with a thickness of 15 μm on a polyester film with a thickness of 38 μm) having an opening (exposed area) of 3 mm was formed in a region corresponding to the central portion with a diameter of 5 mm where toluene was immersed in the above (b), and then the toluene was immersed in the opening for 10 seconds under the condition of 40 °C. Next, after removing the toluene, the protective film was peeled off to obtain a polarizing film 2 having a region 2-2 in the central portion of region 2-1. The visual sensitivity corrected single transmittance (Ty) and the visual sensitivity corrected polarization degree (Py) of the obtained region 2-2 of the polarizing film 2 were measured according to the method described below. The results are shown in Table 1.

[0201] <Measurement of Visual Sensitivity Corrected Single Transmittance (Ty) and Visual Sensitivity Corrected Polarization Degree (Py)> For the obtained polarizing film, the visual sensitivity corrected single transmittance (Ty) and the visual sensitivity corrected polarization degree (Py) were calculated by the following procedure. The transmittance (T 1 ) in the transmission axis direction and the transmittance (T 2 ) in the absorption axis direction in the wavelength range of 380 nm to 780 nm were measured by the double beam method using an apparatus in which a folder with a polarizer was set in a spectrophotometer (UV-3150 manufactured by Shimadzu Corporation). A mesh for cutting the light amount by 50% was installed on the reference side of the folder. The measurement diameter in each region was narrowed to a circular diameter of 1 mm. According to the following (Equation 1) and (Equation 2), the transmittance and polarization degree at each wavelength were calculated, and further visual sensitivity correction was performed by the 2-degree field of view (C light source) of JIS Z 8701 to calculate the visual sensitivity corrected single transmittance (Ty) and the visual sensitivity corrected polarization degree (Py). Polarization degree [%] = {(T 1 - T 2 ) / (T 1 + T 2 )} × 100 (Equation 1) Single transmittance [%] = (T 1 + T 2 ) / 2 (Equation 2)

[0202] <Evaluation of Region Contour> Regarding the obtained polarizing film, under natural light conditions, at a distance of 1 m, visually confirm the region contours of the first region and the second region, and evaluate according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) 4. The contour was difficult to visually recognize. 3. The contour was slightly visually recognized. 2. The contour was vaguely visually recognized. 1. The contour was clearly visually recognized.

[0203] <Evaluation of Polarization Performance> The degree of polarization of the second region (region 2-2) of the obtained polarizing film was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation Criteria) 4. Degree of polarization is 50% or more 3. Degree of polarization is 40% or more and less than 50% 2. Degree of polarization is 30% or more and less than 40% 1. Degree of polarization is 0% or more and less than 30%

[0204] 2. Example 2 A polarizing film having region 2-2 at the center of region 2-1 was produced and performance evaluated in the same manner as in Example 1, except that a protective film (AY-638 manufactured by Fujimori Kogyo Co., Ltd., composed of a 38-μm-thick polyester film and a 15-μm-thick adhesive layer) with a 2-mm opening was used in the formation process of the second region (region 2-2). The results are shown in Table 1.

[0205] 3. Example 3 A polarizing film having region 2-2 at the center of region 2-1 was produced and performance evaluated in the same manner as in Example 2, except that the immersion time in toluene in the formation process of the second region (region 2-1) was 90 seconds and the immersion time in toluene in the formation process of the second region (region 2-2) was 15 seconds under 40°C conditions. The results are shown in Table 1.

[0206] 4. Example 4 A polarizing film having Region 2-2 at the center of Region 2-1 was produced and performance-evaluated in the same manner as in Example 3, except that the immersion time in toluene in the formation process of the second region (Region 2-2) was 30 seconds under the condition of 40°C. The results are shown in Table 1.

[0207] 5. Example 5 A polarizing film 2 having Region 2-1-2 at the center of Region 2-1-1 was produced in the same manner as in Example 1, except that a protective film (AY-638 manufactured by Fujimori Kogyo Co., Ltd., composed of a 15-μm-thick adhesive layer on a 38-μm-thick polyester film) with a 4-mm opening formed in the formation process of the second region (Region 2-2) was used. Next, a protective film (AY-638 manufactured by Fujimori Kogyo Co., Ltd., composed of a 15-μm-thick adhesive layer on a 38-μm-thick polyester film) with a 3-mm opening (exposed region) was formed in the region corresponding to the central part with a 4-mm diameter where toluene was immersed in the process for forming Region 2-1-2. After laminating, toluene was immersed in the opening for 10 seconds under the condition of 40°C. Then, after removing the toluene, the protective film was peeled off to obtain a polarizing film 3 having Region 2-1-2 inside Region 2-1-1 and further having Region 2-2 at the inner central part of Region 2-1-2. For the obtained polarizing film 3, in the same manner as in Example 1, the visual sensitivity-corrected single transmittance (Ty) and visual sensitivity-corrected degree of polarization (Py) of each region were measured, and performance evaluation was performed. The results are shown in Table 1.

[0208] 6. Example 6 A polarizing film having Region 2-2 at the center of Region 2-1 was produced and performance-evaluated in the same manner as in Example 2, except that in the formation process of the second region (Region 2-1), dimethyl sulfoxide was used instead of toluene and the immersion condition was 60 seconds at 80°C, and in the formation process of the second region (Region 2-2), dimethyl sulfoxide was used instead of toluene and the immersion condition was 90 seconds at 80°C. The results are shown in Table 1.

[0209] 7. Example 7 In the step of forming the second region (region 2-1), a protective film (AY-638 manufactured by Fujimori Kogyo Co., Ltd., composed of an adhesive layer with a thickness of 15 μm on a polyester film with a thickness of 38 μm) having an opening of 5 mm was used to form region 2-1. Except that the step of forming the second region (region 2-2) was not performed, a polarizing film having a second region with a uniform visual sensitivity correction single transmittance inside the first region was produced and performance evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0210] 8. Example 8 In the step of forming the second region (region 2-2), except that anisole was immersed for 10 seconds at room temperature (25 °C) instead of toluene, a polarizing film having region 2-2 at the center of region 2-1 was produced and performance evaluation was carried out in the same manner as in Example 2. The results are shown in Table 1.

[0211] 9. Comparative Example 1 In the step of forming the second region (region 2-1), except that anisole was immersed for 10 seconds at room temperature (25 °C) instead of toluene and the step of forming the second region (region 2-2) was not performed, a polarizing film having a comparative second region with a difference from the visual sensitivity correction single transmittance of the first region exceeding 30% inside the first region was produced and performance evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0212]

Table 1

Explanation of Symbols

[0213] 1: First region 2: Second region 3: Region 2-1 4: Region 2-2 11: Polarizing film 12: Substrate layer 13: Polarizing layer 14: Laminated film 15, 16: Laminated film with protective film 20, 25: Protective film 21, 23: Coated area 22, 24: Exposed area a: Visual sensitivity correction single transmittance of the second area a-1: Visual sensitivity correction single transmittance of area 2-1 a-2: Visual sensitivity correction single transmittance of area 2-2 b: Visual sensitivity correction single transmittance of the first area

Claims

1. A polarizing film including a polarizing layer and a substrate layer, the polarizing layer is made of a cured layer of a liquid crystal composition containing a dichroic dye and a liquid crystal compound; a first region in a plane direction of the polarizing film; and a second region adjacent to the inside of the first region in the plane direction and having a luminous efficiency corrected single transmittance higher than that of the first region, the second region includes a region X having a luminosity-corrected single transmittance that is less than 30% different from that of the first region and a luminosity-corrected polarization degree that is greater than 10%, The second region is composed of a region 2-1 that contacts the first region and a region 2-2 that is located inside the region 2-1. The difference between the maximum and minimum values ​​of the visibility-corrected single transmittance in the region 2-2 is within 2% and is higher than the visibility-corrected single transmittance in the region 2-1. A polarizing film, wherein the second region has a planar shape that is circular, elliptical, oval or polygonal.

2. The polarizing film according to claim 1 , wherein the region X exists continuously from an outer periphery of the second region in contact with the first region toward the inside.

3. The polarizing film of claim 1 or 2, wherein the second region has at least two different luminous-corrected single transmittances.

4. 4. The polarizing film according to claim 1, wherein the difference between the luminosity-corrected single transmittance of the second region and the luminosity-corrected single transmittance of the first region is less than 30% over the entire second region.

5. 5. The polarizing film according to claim 1, wherein the first region has a luminosity-corrected single transmittance of 30% or more and less than 55%.

6. 6. The polarizing film according to claim 1, wherein the region X has a luminosity-corrected single transmittance of 45% or more and 70% or less.

7. 7. The polarizing film according to claim 1, wherein the region X has a luminosity-corrected polarization degree of 30% or more and 85% or less.

8. 8. The polarizing film according to claim 1, wherein the luminosity-corrected single transmittance of the second region increases stepwise from the outer periphery of the second region toward the inside.

9. 9. The polarizing film according to claim 1, wherein the visibility-corrected single transmittance of the region 2-1 increases stepwise toward the region 2-2.

10. The polarizing film according to any one of claims 1 to 9, wherein the luminosity-corrected single transmittance of the region 2-2 is 45% or more and 70% or less.

11. The polarizing film according to any one of claims 1 to 10, further comprising an alignment layer between the polarizing layer and the substrate layer.

12. An elliptically polarizing plate comprising the polarizing film according to any one of claims 1 to 11 and a retardation film.

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