TW201809747A - Polarizing plate, image display device and method for manufacturing polarizing plate - Google Patents

Abstract

The present invention provides a polarizing plate capable of suppressing cracks caused by temperature change at a notch portion of a polarizer. The polarizing plate (1A) has a film-like polarizer (7), wherein a concave notch (7C) is formed at the end (7e) of the polarizer (7); when a reference line L is defined as a straight line connecting a pair of corner portions (7C1, 7C2) positioned at both ends of the notch portion (7C), the reference line L is not orthogonal to the absorption axis A of the polarizer 7; Wc is the width of the notch (7C) in the direction parallel to the reference line L; W is the width of the entire polarizer (7) in a direction parallel to the reference line L; and Wc/W is 0.05 or more and less than 1.0.

Description

Polarizing plate, image display device, and manufacturing method of polarizing plate

The present invention relates to a method for manufacturing a polarizing plate, an image display device, and a polarizing plate.

The polarizing plate is one of the optical components constituting an image display device such as a liquid crystal television, an organic EL television, or a smart phone. The polarizing plate includes a film-shaped polarizer and an optical film (for example, a protective film) laminated on the polarizer. Due to design reasons of the image display device, a cut-out portion is sometimes formed at an end portion of the polarizer. For example, in Patent Document 1 described below, it is described that a notch is formed at an end of a polarizer as an injection port for liquid crystal.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-155325

Polarizers expand or contract with changes in temperature. According to the research by the present inventors, it was found that the polarizer with temperature change The cause of the shrinkage is a crack in the notch. In particular, cracks are more likely to occur due to thermal shock (rapid temperature changes).

The present invention has been made in view of the foregoing circumstances, and an object thereof is to provide a polarizing plate capable of suppressing cracks caused by temperature changes on a notch portion of a polarizer, an image display device including the polarizing plate, and a method of manufacturing a polarizing plate. .

The one-layer polarizing plate of the present invention is provided with a film-shaped polarizer, and a concave notch is formed at the end of the polarizer. When the reference line L is defined as a straight line connecting the diagonal portions at two ends of the notch At this time, the reference line L is not orthogonal to the absorption axis A of the polarizer, Wc is the width of the notch in the direction parallel to the reference line L, W is the width of the entire polarizer in the direction parallel to the reference line L, Wc / W is 0.05 or more and less than 1.0. In other words, the angle θ formed by the reference line L and the absorption axis A of the polarizer is 0 ° or more and less than 90 °.

In one aspect of the present invention, the polarizer may have a first end portion and a second end portion opposite to the first end portion, a notch portion may be formed at the first end portion, and the notch portion may be formed from the first end portion. Extending toward the second end portion, the direction E in which the notch portion extends may not be parallel to the absorption axis A of the polarizer. In other words, the angle α formed by the direction E in which the notch portion extends and the absorption axis A of the polarizer may be greater than 0 ° and 90 ° or less.

In one aspect of the present invention, a method for manufacturing a polarizing plate includes the steps of manufacturing a first multilayer body including a polarizer film and at least one optical film superimposed on the polarizer film, and processing the first multilayer body to shape it. A step of forming a second laminated body having a first end portion that is not orthogonal to the absorption axis A of the polarizer film, and a step of forming a concave notch portion on the aforementioned first end portion of the second laminated body; The line L is defined as a straight line connecting one diagonal portion at both ends of the notch portion, Wc is the width of the notch portion in a direction parallel to the reference line L, and W is the entire polarizer in the direction parallel to the reference line L The width of Wc / W is adjusted to 0.05 or more and less than 1.0.

In the manufacturing method of the polarizing plate in one aspect of the present invention, the second laminated body may have a second end portion located on the opposite side of the first end portion, and the notch portion may be directed from the first end portion toward the second end portion. Extend and adjust the direction E in which the notch portion extends to a direction that is not parallel to the absorption axis A. In other words, the angle α formed by the direction E in which the notch portion extends and the absorption axis A of the polarizer film (polarizer) can be adjusted to be greater than 0 ° and 90 ° or less.

A polarizing plate according to another aspect of the present invention includes a film-shaped polarizer. The polarizer has a first end portion and a second end portion opposite to the first end portion, and a concave notch portion is formed at the first end portion. The notch portion extends from the first end portion toward the second end portion, and the direction E in which the notch portion extends is not parallel to the absorption axis A of the polarizer, Wc is the width of the notch portion in a direction parallel to the first end portion, W The width of the entire polarizer in a direction parallel to the first end portion, Wc / W is 0.05 or more and less than 1.0. In other words, in the polarizing plate of another aspect of the present invention, the angle α formed by the direction E in which the cutout portion extends and the absorption axis A of the polarizer is greater than 0 ° and 90 ° or less.

A method of manufacturing a polarizing plate according to another aspect of the present invention includes: manufacturing at least one of a polarizing film and a polarizing film A step of a first laminated body of an optical film; a step of processing the first laminated body to produce a second laminated body having a first end portion and a second end portion opposite to the first end portion; and The step of forming the notch portion on the first end portion; extending the notch portion from the first end portion toward the second end portion, and adjusting the direction E in which the notch portion extends to a direction not parallel to the absorption axis A, and Wc is parallel to The width of the notch portion in the direction of the first end portion, W is the width of the entire polarizer in the direction parallel to the first end portion, and Wc / W is adjusted to be 0.05 or more and less than 1.0. In other words, the angle α formed by the direction E in which the notch portion extends and the absorption axis A of the polarizer film (polarizer) can be adjusted to be greater than 0 ° and 90 ° or less.

In any one of the above aspects of the present invention, the protective film or the protective layer may adhere to both surfaces of the polarizer.

In any one of the above aspects of the present invention, the protective film or the protective layer may be adhered to only one surface on both surfaces of the polarizer. In any of the above aspects of the present invention, a truncated angle may be formed in a deep portion of the notch portion.

An image display device according to any one of the above aspects of the present invention includes the above-mentioned polarizing plate.

According to the present invention, there are provided a polarizing plate, an image display device including the polarizing plate, and a method of manufacturing a polarizing plate. The notch portion of the polarizing plate can suppress cracks caused by temperature changes.

1A, 1Aa, 1Ab, 1B, 1Ba, 1Bb, 1C‧‧‧ polarizing plate

3‧‧‧ third protective film

5‧‧‧first protective film

7‧‧‧ polarizer

7C‧‧‧Notch

7C1, 7C2‧‧‧ are located at one of the diagonal ends of the notch 7C

7Cd‧‧‧Deep part of 7C

7C3, 7C4

7cr‧‧‧crack

7e‧‧‧ end of the polarizer (first end)

9‧‧‧Second protective film

10‧‧‧ LCD cell

11‧‧‧ Adhesive layer

13‧‧‧ release film

17e‧‧‧ the second end of the polarizer

20A, 20B‧‧‧ LCD panel

30A, 30B‧‧‧ LCD display device (image display device)

A‧‧‧ Absorption axis

E‧‧‧ Direction of notch 7C

L‧‧‧ baseline

S‧‧‧ a line segment connecting a pair of corners 7C1 and 7C2

Sc‧‧‧ Midpoint of Line S

θ‧‧‧ Angle formed by reference line L and absorption axis A

α‧‧‧ Angle formed by the direction E of the notch 7C and the absorption axis A of the polarizer

FIG. 1 is a schematic perspective view of a polarizing plate according to a first embodiment of the present invention.

(A) in FIG. 2 is a plan view of a polarizing plate provided in the polarizing plate shown in FIG. 1, and (b) in FIG. 2 is a modification example of the polarizing plate shown in (a) in FIG. 2 .

FIG. 3 is a plan view of a polarizer included in the polarizing plate shown in FIG. 1 and is an enlarged view of (a) in FIG. 2.

Fig. 4 is a schematic cross-sectional view of an image display device (liquid crystal display device) according to a first embodiment of the present invention.

Fig. 5 is a schematic perspective view of a polarizing plate according to a second embodiment of the present invention.

FIG. 6 is a schematic cross-sectional view of an image display device (liquid crystal display device) according to a second embodiment of the present invention.

(A) in FIG. 7 is a plan view of a polarizing plate provided in a polarizing plate of another embodiment of the present invention, and (b) in FIG. 7 is a view of a polarizing plate provided in a polarizing plate of another embodiment of the present invention. (C) of FIG. 7 is a plan view of a polarizing plate provided in a polarizing plate according to another embodiment of the present invention.

(A) in FIG. 8 is a plan view of a polarizer provided in a polarizing plate according to another embodiment of the present invention, and (b) in FIG. 8 is a view of a polarizer provided in a polarizing plate according to another embodiment of the present invention. (C) in FIG. 8 is a plan view of a polarizer included in the polarizer of the embodiment of the present invention.

Fig. 9 is a plan view of a polarizing plate provided in a polarizing plate according to another embodiment of the present invention.

Fig. 10 is a plan view of a polarizing plate provided in a polarizing plate according to another embodiment of the present invention.

Fig. 11 is a schematic perspective view of a polarizing plate of a comparative example of the present invention.

Fig. 12 is a plan view of a polarizing plate provided in the polarizing plate shown in Fig. 11.

FIG. 13 is a plan view of a polarizing plate provided in a polarizing plate according to an embodiment of the present invention.

The following is a description of a preferred embodiment of the present invention with reference to the drawings. In the drawings, the same symbols are assigned to the same constituent elements. The present invention is not limited to the following embodiments. X, Y, and Z shown in each figure mean three coordinate axes orthogonal to each other. The directions shown by the coordinate axes are common to all figures.

(First Embodiment)

The first embodiment will be described with reference to FIGS. 1, 2 (a), 2 (b), and 3. The polarizing plate 1A of the first embodiment includes a film-shaped polarizer 7 and a plurality of optical films (3, 5, 9, and 13) superposed on the polarizer 7. The polarizer 7 and the plurality of optical films (3, 5, 9, 13) are all quadrangular. The "optical film" means a film-like member (minus the polarizer itself) constituting a polarizing plate. An optical film may also be referred to as a layer or an optical layer. The optical film includes, for example, a protective film and a release film. In the first embodiment, the plurality of optical films (3, 5, 9, 13) are the first protective film 5, the second protective film 9, the third protective film 3, and the release film 13 (separation sheet). That is, the polarizing plate 1A includes polarized light The sheet 7, the first protective film 5, the second protective film 9, the third protective film 3, and the release film 13. The polarizing plate 1A also includes an adhesive layer 11 located between the second protective film 9 and the release film 13. A first protective film 5 is superposed on one surface of the polarizer 7, and a second protective film 9 is superposed on the other surface of the polarizer 7. That is, a protective film (protective layer) is adhered to both surfaces of the polarizer 7. The third protective film 3 is superposed on the first protective film 5. That is, the first protective film 5 is located between the polarizer 7 and the third protective film 3. The release film 13 is superimposed on the second protective film 9 via the adhesive layer 11. In other words, the second protective film 9 is located between the polarizer 7 and the adhesive layer 11.

A concave cutout 7C (concave cut-out portion) is formed on an end portion (first end portion 7e) of the polarizer 7. This notched portion 7C penetrates the polarizer 7 and the optical film (3, 5, 9, 13) in the laminated direction (Z-axis direction) of the polarizer 7, the optical film (3, 5, 9, 13) and the adhesive layer 11. ) And all of the adhesive layer 11. That is, the end face of the polarizing plate 1A is formed with a concave notch common to all of the polarizing plate 7, the optical films (3, 5, 9, 13) and the adhesive layer 11 constituting the polarizing plate 1A. The shape of the notch portion 7C of the polarizer 7 viewed from the lamination direction (Z-axis direction) may be the same as or similar to the shape of the notch portion of the polarizing plate 1A viewed from the lamination direction. The shape of the notch portion of the polarizing plate 1A viewed from the lamination direction may be regarded as the shape of the notch portion 7C of the polarizer 7 viewed from the lamination direction. Hereinafter, not only the notched portion 7C of the polarizer 7 but also the notched portion of the polarizing plate 1A including the notched portion 7C may be described as “notched portion 7C”. The cutout portion 7C is, for example, rectangular.

The reference line L is defined as connecting two One of the ends is a straight line of the diagonal portions 7C1 and 7C2. The reference line L may be referred to as a straight line connecting the pair of corner portions 7C1 and 7C2 in a direction perpendicular to the above-mentioned lamination direction (Z-axis direction). This reference line L is not orthogonal to the absorption axis A of the polarizer 7. In other words, the angle θ formed by the reference line L of the notch portion 7C and the absorption axis A of the polarizer 7 is 0 ° or more and less than 90 °. The absorption axis A may be referred to as, for example, a straight line substantially parallel to the alignment direction of the polyvinyl alcohol (PVA) molecules in the polarizer 7. The absorption axis A may be referred to as a straight line on the polarizer 7 that is substantially parallel to the alignment direction of the pigment molecules (for example, polyiodine or organic dye) adsorbed on the polyvinyl alcohol. It can be said that many carbon atoms constituting one PVA molecule are bonded to each other by a covalent bond (C-C bond) along the absorption axis A. On the other hand, in a direction substantially perpendicular to the absorption axis A, the PVA molecules are bonded to each other by a cross-linking bond between a cross-linking agent (for example, boric acid). In other words, in a direction substantially perpendicular to the absorption axis A, the hydroxyl groups of each PVA molecule form a hydrogen bond or an oxygen-boron bond (O-B bond) with boric acid located between the PVA molecules, thereby crosslinking the PVA molecules with each other. The C-C bond formed along the absorption axis A is stronger than the cross-linked bond formed along a direction substantially perpendicular to the absorption axis A. Therefore, the mechanical strength of the polarizer 7 in a direction substantially parallel to the absorption axis A is large, so that the mechanical strength of the polarizer 7 in a direction perpendicular to the absorption axis A is high. In other words, the thermal contraction of the polarizer 7 in a direction substantially parallel to the absorption axis A is less likely to cause cracking than the thermal contraction of the polarizer 7 in a direction substantially perpendicular to the absorption axis A.

As shown in FIGS. 11 and 12, when the reference line L is orthogonal to the absorption axis A (when the angle θ is 90 °), In the direction parallel to the reference line L, a weaker cross-linking bond is formed compared to the C-C bond in the PVA molecule. Therefore, when the reference line L is orthogonal to the absorption axis A, when a deep portion (depth portion) of the notch portion 7C contracts in a direction substantially parallel to the reference line L, a crack 7cr is easily generated in the deep portion of the notch portion 7C.

On the other hand, in the first embodiment, the reference line L is not orthogonal to the absorption axis A of the polarizer 7. In other words, the angle θ formed by the reference line L and the absorption axis A is 0 ° or more and less than 90 °. Compared with the cross-links between the PVA molecules, the stronger C-C bonds in the PVA molecules can increase the mechanical strength of the polarizer 7 in a direction parallel to the reference line L. As a result, even if the deep portion of the notched portion 7C is contracted in a direction substantially parallel to the reference line L, cracks 7cr are hardly generated in the deep portion of the notched portion 7C. Especially when the reference line L is parallel to the absorption axis A (when the angle θ is 0 °), the C-C bonds in most of the PVA molecules constituting the polarizer 7 are formed along the absorption axis A. Therefore, when the reference line L is parallel to the absorption axis A, the mechanical strength of the polarizer 7 in a direction parallel to the reference line L is significantly improved, and the formation of cracks 7cr in the notch 7C is significantly suppressed.

The smaller the angle θ formed by the reference line L and the absorption axis A, the more difficult it is to form a crack 7cr in the notch 7C. The angle θ is 0 ° to 75 ° or 0 ° to 60 °.

The polarizer 7 has a first end portion 7e in which a notch portion 7C is formed, and a second end portion 17e on the opposite side of the first end portion 7e. In the first embodiment, both the first end portion 7e and the second end portion 17e are linear, and the first end portion 7e is parallel to the second end portion 17e. The cutout portion 7C extends from the first end portion 7e toward the second end portion 17e. The direction E in which the notch 7C extends, does not Parallel to the absorption axis A of the polarizer 7. In other words, the angle α formed by the direction E in which the notch 7C extends and the absorption axis A is greater than 0 ° and 90 ° or less. In the first embodiment, the angle α is 90 °. In the first embodiment, the direction E in which the cutout portion 7C extends is equal to the longitudinal direction of the cutout portion 7C. That is, the longitudinal direction of the notch 7C is along the direction E in which the notch 7C extends.

Since the direction E extending from the notch 7C is not parallel to the absorption axis A of the polarizer 7, compared with the cross-linking bond between the PVA molecules, the CC bond in the stronger PVA molecule can increase the direction perpendicular to the direction E The mechanical strength of the upper polarizer 7. As a result, even if the deep portion of the notched portion 7C is contracted in a direction substantially perpendicular to the direction E, cracks 7cr are hardly generated in the deep portion of the notched portion 7C. The larger the angle α formed by the direction E and the absorption axis A, the more difficult it is to form a crack 7cr in the notch 7C. Especially when the direction E is perpendicular to the absorption axis A (when the angle α is 90 °), the C-C bonds in most of the PVA molecules constituting the polarizer 7 are formed perpendicular to the direction E. Therefore, when the direction E is perpendicular to the absorption axis A, the mechanical strength of the polarizer 7 in the direction perpendicular to the direction E is remarkably improved, and the formation of cracks 7cr in the notch 7C is significantly suppressed.

The width Wc of the notch portion 7C in the direction parallel to the reference line L may be, for example, 2 mm or more and less than 600 mm, or 5 mm or more and 30 mm or less. The width Wc may also be referred to as the width of the notch portion 7C in a direction parallel to the end portion (first end portion 7e) of the polarizer 7, and the width W of the entire polarizer 7 in a direction parallel to the reference line L. For example, it may be 30 mm or more and 600 mm or less. The width W of the entire polarizer 7 may be referred to as The width of the entire polarizing plate 1A running in the direction of the reference line L. The width W may also be referred to as the width of the entire polarizer 7 in a direction parallel to the first end portion 7e. The width Wc of the notch portion 7C may be, for example, less than the width W of the entire polarizer 7. When the width Wc of the notch portion 7C is 5 mm or more and 30 mm or less, the width W of the entire polarizing plate 7 (the width of the entire polarizing plate 1A) is greater than 20 mm and 160 mm or less, preferably more than 25 mm and 130 mm or less, and particularly preferably It is more than 30 mm and 100 mm or less, more preferably more than 30 mm and 70 mm or less (but Wc <W). The ratio Wc / W of the width Wc of the notch portion 7C to the width W of the entire polarizer 7 is 0.05 or more and less than 1.0. The ratio Wc / W is 0.08 or more and less than 1.0, 0.10 or more and less than 1.0 or 0.13 or more and less than 1.0, preferably 0.15 or more and less than 1.0 or 0.17 or more and less than 1.0, particularly preferably 0.20 or more and less than 1.0 or 0.22 or more and less than 1.0, more preferably 0.30 or more and less than 1.0, 0.33 or more and less than 1.0 or 0.40 or more and less than 1.0. The ratio Wc / W may be from 0.05 to 0.90, from 0.05 to 0.80, from 0.05 to 0.78, or from 0.05 to 0.45. The ratio Wc / W may be referred to as a ratio of the width Wc of the notch 7C to the width W of the entire polarizing plate 1A. When the ratio Wc / W is within the above range, it is easy to suppress cracking in the notched portion 7C. The reason is as follows. The smaller the width Wc of the notch 7C is than the width W of the entire polarizer 7, the shrinkage of the entire polarizer 7 accompanying the temperature change leads to a greater force to expand the width Wc of the notch 7C, which makes the notch 7C easier Cracks occur. On the other hand, the larger the Wc / W (the smaller the width W of the entire polarizer 7), the smaller the shrinkage amount of the entire polarizer 7 due to the temperature change. That is, the smaller the width W of the entire polarizer 7 is, the more the entire polarizer 7 can be reduced. The absolute value of the amount of change in the width W. Since the amount of shrinkage of the entire polarizing plate 7 accompanying the temperature change is reduced, it is less likely to generate a force that widens the width Wc of the notched portion 7C, and it is easy to suppress cracks in the notched portion 7C.

The length Dc of the notch portion 7C in the direction perpendicular to the reference line L may be, for example, 1 mm or more and 30 mm or less. The length Dc may be referred to as a depth of the notch portion 7C in a direction perpendicular to the reference line L. The length D of the entire polarizer 7 in a direction perpendicular to the reference line L is, for example, 30 mm or more and 600 mm or less. The length D of the entire polarizing plate 7 may be referred to as the length of the entire polarizing plate 1A in a direction perpendicular to the reference line L. The thickness of the polarizing plate 1A is, for example, 10 μm or more and 1200 μm or less, 10 μm or more and 500 μm or less, 10 μm or more and 300 μm or less, or 10 μm or more and 200 μm or less.

The manufacturing method of the polarizing plate 1A includes at least a bonding step and a processing step. In the bonding step, a long strip-shaped polarizer film and a plurality of long strip-shaped optical films are bonded together to produce a laminated body (first laminated body). The long strip-shaped polarizer film is the polarizer 7 before processing. The absorption axis of the polarizer film may be the same as the absorption axis A of the polarizer 7 after processing. A plurality of so-called long strip-shaped optical films are optical films (3, 5, 9, 13) before processing. In subsequent processing steps, the first laminated body is processed to produce a plurality of laminated bodies (second laminated bodies) having a desired size and shape. This second laminated body has a first end portion 7e that is not orthogonal to the absorption axis A of the polarizer film (polarizer 7) and a second end located on the side opposite to the first end portion 7e, similar to the polarizing plate 1A. Department 17e. In the processing step, for example, the first laminated body may be cut in a direction that is not orthogonal to the absorption axis A of the polarizer film to form a first end portion that is not orthogonal to the absorption axis A. In the processing step, for example, the second laminated body can be produced by cutting the first laminated body with a blade. In the processing step, for example, the second laminated body can be produced by press working of the first laminated body. In the processing step, for example, the first laminated body can be cut by laser to form a second laminated body. The laser is, for example, a CO ₂ laser or an excimer laser. In the processing step, for example, the second laminated body can be produced by combining cutting using the blade, press processing, and cutting using laser in combination. After the first laminated body is processed by the above processing method to adjust the size of the first laminated body to be larger than a predetermined size, the end of the first laminated body is cut and ground by a milling cutter to produce a second laminated body .

In the processing step, a concave notch portion 7C may be formed at the first end portion 7e of the second laminated body by, for example, press working or cutting with a blade or laser. When the notch portion 7C is formed in the processing step, the notch portion 7C is extended from the first end portion 7e toward the second end portion 17e, and the direction E in which the notch portion 7C extends is adjusted to a direction not parallel to the absorption axis A. In the processing step, after the second laminated body having the notch 7C is formed, an end processing step may be performed. In the end processing step, for example, an end mill can be used to cut and polish the end surface of the second laminated body including the notch 7C. End mill is a kind of milling cutter used in cutting. The end milling cutter cuts and polishes the end surface of the second laminated body including the notch portion 7C by a tool located on a side surface substantially parallel to its rotation axis, for example. As a result, the end surface of the second laminated body including the notched portion 7C can be smoothly finished. By using this end mill, the second laminated body can be formed into a polarizing plate 1A having a desired shape and size in a short time. That is, the polarizing plate 1A can be improved. Productive. In the processing step, a larger first laminated body is punched out to produce a second laminated body. In a subsequent end processing step, an end face of the second laminated body is cut and ground by an end mill. As a result, the margin of the end portion removed from the second laminated body in the end processing step is reduced, the generation of impurities such as abrasive dust in the end processing step is suppressed, and the incorporation of impurities into the product (polarized light) is suppressed. Board 1A).

Instead of forming the notch portion 7C in the processing step, the notch portion 7C may be formed on the first end portion 7e of the second laminated body in the end surface processing step subsequent to the processing step. When the notch portion 7C is formed in the end surface processing step, the notch portion 7C is also extended from the first end portion 7e toward the second end portion 17e, and the direction E in which the notch portion 7C extends is adjusted to a direction not parallel to the absorption axis A . In the end portion processing step, for example, the laser may be irradiated to the end portion of the second laminated body, and a part or all of the end portion may be cut, thereby forming the notch portion 7C in the second laminated body. It is also possible to form the notch portion 7C in the second laminated body by using the above-mentioned end portion processing step of the end mill. In addition, in any of the processing steps or the end processing steps, Wc / W is adjusted to be 0.05 or more and less than 1.0.

The direction of the absorption axis A of the polarizer 7 included in the second laminated body has been grasped at the time of the processing step and the end surface processing step. Therefore, as described above, for example, the direction of punching or cutting of the first laminated body is adjusted to adjust the angle formed by the first end portion 7e of the second laminated body and the absorption axis A to be 0 ° or more and less than 90 ° Therefore, the angle θ formed by the reference line L and the absorption axis A can be controlled freely within a range of 0 ° to 90 °. In addition, as described above, the notch portion 7C is formed on the first of the second laminated body. At the end portion 7e, by adjusting the orientation of the notch portion 7C, the angle α formed by the direction E and the absorption axis A can be freely controlled within a range greater than 0 ° and not more than 90 °. As described above, the relative positional relationship between the reference line L and the absorption axis A can be controlled by the direction of punching or cutting of the first laminate and the position of the notch 7C formed in the second laminate. The relative positional relationship between the direction E and the absorption axis A can be controlled by the position of the notch portion 7C and the orientation of the notch portion 7C in the second laminate. The direction of the absorption axis A in the polarizer film (polarizer 7) itself can be adjusted and controlled in comparison with the stretching direction and stretching ratio of the PVA film performed before the processing step and the end surface processing step.

The polarizer 7 may be a film-like polyvinyl alcohol-based resin (PVA film) produced through processes such as stretching, dyeing, and crosslinking. The details of the polarizer 7 are described below.

For example, the PVA film is first stretched uniaxially or biaxially. The two-color ratio of the polarizer 7 stretched in the uniaxial direction tends to be higher. After stretching, the PVA film is then dyed with iodine, a dichroic pigment (polyiodine), or an organic dye using a dyeing solution. The dyeing solution may contain boric acid, zinc sulfate, and zinc chloride. Wash the PVA film with water before dyeing. By washing with water, dirt and anti-clotting agent can be removed from the surface of the PVA film. In addition, the PVA film was swollen by washing with water, and as a result, stained spots (uneven staining) could be easily suppressed. For crosslinking, the dyed PVA film is treated with a solution of a crosslinking agent (for example, an aqueous solution of boric acid). After the treatment with the crosslinking agent, the PVA film was washed with water and then dried. Through the above steps, a polarizer 7 can be obtained. The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. Polyvinyl acetate The ester-based resin may be, for example, polyvinyl acetate, a homopolymer of vinyl acetate, or a copolymer of vinyl acetate and another monomer (for example, an ethylene-vinyl acetate copolymer). Other monomers copolymerized with vinyl acetate may be unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, or acrylamides having ammonium groups in addition to ethylene. Polyvinyl alcohol resin can be modified by aldehydes. The modified polyvinyl alcohol-based resin may be, for example, partially formaldehydeized polyvinyl alcohol, polyvinyl acetal, or polyvinyl butyral. The polyvinyl alcohol-based resin may be a polyolefin-based alignment film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride. It can be dyed before stretching or stretched in a dyeing solution. The length of the stretched polarizer 7 is, for example, 3 to 7 times the length before stretching.

The thickness of the polarizer 7 is, for example, 1 μm or more and 50 μm or less, 1 μm or more and 10 μm or less, 1 μm or more and 8 μm or less, 1 μm or more and 7 μm or less, or 4 μm or more and 30 μm or less. The thinner the polarizer 7 is, the more it is possible to suppress the shrinkage of the polarizer 7 itself accompanying the temperature change, and to suppress the change in the size of the polarizer 7 itself. As a result, stress is not easily applied to the polarizer 7 and cracks in the polarizer 7 are easily suppressed.

The first protective film 5 and the second protective film 9 may be thermoplastic resins having translucency, and may be optically transparent thermoplastic resins. The resin constituting the first protective film 5 and the second protective film 9 may be, for example, a chain polyolefin resin, a cyclic olefin polymer resin (COP resin), a cellulose ester resin, a polyester resin, or a polycarbonate. Ester-based resin, (meth) acrylic resin, polystyrene-based resin, or a mixture or copolymer thereof. The composition of the first protective film 5 may be exactly the same as that of the second protective film 9. First The composition of one protective film 5 may be different from that of the second protective film 9.

The chain polyolefin resin may be, for example, a homopolymer of a chain polyolefin such as a polyethylene resin or a polypropylene resin. The chain polyolefin resin may be a copolymer composed of two or more chain polyolefins.

The cyclic olefin polymer-based resin (cyclic polyolefin-based resin) may be, for example, a ring-opened (co) polymer of a cyclic olefin, or an addition polymer of a cyclic olefin. The cyclic olefin polymer-based resin may be, for example, a copolymer (for example, a random copolymer) of a cyclic olefin and a chain olefin. The chain olefin constituting the copolymer may be, for example, ethylene or propylene. The cyclic olefin polymer-based resin may be a graft polymer in which the above-mentioned polymer is modified by an unsaturated carboxylic acid or a derivative thereof, or a hydride thereof. The cyclic olefin polymer-based resin may be a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer.

The cellulose ester-based resin may be, for example, cellulose triacetate (cellulose triacetate (TAC)), cellulose diacetate, cellulose tripropionate, or cellulose dipropionate. These copolymers can be used. It is also possible to use a cellulose ester resin in which a part of the hydroxyl group is modified with other substituents.

Polyester resins other than cellulose ester resins can be used. The polyester resin may be, for example, a polycondensate of a polycarboxylic acid or a derivative thereof and a polyhydric alcohol. The polycarboxylic acid or a derivative thereof may be a dicarboxylic acid or a derivative thereof. The polycarboxylic acid or a derivative thereof may be, for example, terephthalic acid, isophthalic acid, dimethyl terephthalic acid, or dimethyl naphthalate. The polyol may be, for example, a diol. The polyol may be, for example, ethylene glycol, propylene glycol, butanediol, neopentyl glycol, or cyclohexanedimethanol.

The polyester resin may be, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, Polypropylene naphthalate, cyclohexane dimethyl terephthalate or cyclohexane dimethyl polynaphthalate.

A polycarbonate-based resin is a polymer in which a polymerized unit (monomer) is bonded via a carbonate group. The polycarbonate-based resin may be a modified polycarbonate having a modified polymer skeleton, or a copolymerized polycarbonate.

The (meth) acrylic resin may be, for example, poly (meth) acrylate (such as polymethyl methacrylate (PMMA)); methyl methacrylate- (meth) acrylic copolymer; methyl methacrylate- (Meth) acrylate copolymer; methyl methacrylate-acrylate- (meth) acrylic copolymer; methyl methacrylate-styrene copolymer (such as MS resin); methyl methacrylate Copolymers of cyclic hydrocarbon-based compounds (such as methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-norbornene methacrylate copolymer, etc.).

The optical film of at least one of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 may contain cellulose triacetate (TAC). The optical film of at least one of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 may contain a cyclic olefin polymer resin (COP resin). The optical film of at least one of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 may contain polymethyl methacrylate (PMMA). Both of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching one of the polarizers 7 may contain cellulose triacetate. Hold one of the pair of polarizers 7 (the first protective film 5 and the second protective film) One of the films 9) may contain cellulose triacetate, and the other one of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching one of the polarizers 7 may include a ring shape. Olefin polymer. One of the optical films (the first protective film 5 and the second protective film 9) sandwiching one of the polarizers 7 may contain cellulose triacetate, and one of the optical films sandwiching one of the polarizers 7 (first protection) The other one of the film 5 and the second protective film 9) may contain polymethyl methacrylate. One of the optical films (the first protective film 5 and the second protective film 9) sandwiching one of the polarizers 7 may contain a cyclic olefin polymer resin, and one of the optical films ( The other one of the first protective film 5 and the second protective film 9) may contain polymethyl methacrylate. When the polarizer 7 is sandwiched between a pair of optical films (the first protective film 5 and the second protective film 9), the optical film (protective film) is closely adhered to the polarizer 7, so that the polarizer accompanying temperature change can be suppressed. The expansion or contraction of 7 makes it difficult to generate cracks in the polarizer 7. For example, when the polarizer 7 is sandwiched between the first protective film 5 made of TAC and the second protective film 9 made of COP resin, cracks in the polarizer 7 are less likely to occur.

The first protective film 5 or the second protective film 9 may contain at least one selected from the group consisting of a lubricant, a plasticizer, a dispersant, a heat stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent, and an antioxidant. An additive.

The thickness of the first protective film 5 is, for example, 5 μm or more and 90 μm or less, 5 μm or more and 80 μm or less, or 5 μm or more and 50 μm or less. The thickness of the second protective film 9 is also, for example, 5 μm or more and 90 μm or less, 5 μm or more and 80 μm or less, or 5 μm or more and 50 μm or less.

The first protective film 5 or the second protective film 9 may also be a film having optical functions such as a retardation film or a brightness enhancement film. For example, by stretching a film made of the above-mentioned thermoplastic resin or forming a liquid crystal layer on the film, a retardation film having an arbitrary retardation value can be obtained.

The first protective film 5 may be bonded to the polarizer 7 via an adhesive layer. The second protective film 9 may be bonded to the polarizer 7 via an adhesive layer. The adhesive layer may contain a water-based adhesive such as polyvinyl alcohol or an active energy ray-curable resin described later.

The active energy ray-curable resin is a resin that is hardened by irradiating an active energy ray. The active energy rays may be, for example, ultraviolet rays, visible light, electron beams, or X-rays. The active energy ray-curable resin may be an ultraviolet-curable resin.

The active energy ray-curable resin may be a single resin or a plurality of resins. For example, the active energy ray-curable resin may contain a cation polymerizable curable compound or a radical polymerizable curable compound. The active energy ray-curable resin may contain a cationic polymerization initiator or a radical polymerization initiator to start the curing reaction of the curable compound.

The cationically polymerizable sclerosing compound may be, for example, an epoxy-based compound (a compound having at least one epoxy group in the molecule) or an oxo-series compound (a compound having at least one oxo ring in the molecule). The radically polymerizable sclerosing compound may be, for example, a (meth) acrylic compound (a compound having at least one (meth) acryloxy group in the molecule), and the radically polymerizable sclerosing compound may be free Radical polymerizability Double bond of vinyl compounds.

The active energy ray hardening resin may contain a cationic polymerization accelerator, an ion trapping agent, an antioxidant, a chain transfer agent, an adhesion imparting agent, a thermoplastic resin, a filler, a flow modifier, a plasticizer, an antifoaming agent, and an antistatic agent as necessary , Leveling agent, or solvent.

The adhesive layer 11 may contain a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, or a urethane-based pressure-sensitive adhesive. . The thickness of the adhesive layer 11 is, for example, 2 μm to 500 μm, 2 μm to 200 μm or less, or 2 μm to 50 μm.

The resin constituting the third protective film 3 may be the same as the resins listed above as the resin constituting the first protective film 5 or the second protective film 9. The thickness of the third protective film 3 is, for example, 5 μm to 200 μm.

The resin constituting the release film 13 may be the same as the resins listed above as the resin constituting the first protective film 5 or the second protective film 9. The thickness of the release film 13 is, for example, 5 μm to 200 μm.

The image display device of the present invention may be, for example, a liquid crystal display device or an organic EL display device. For example, as shown in FIG. 4, the liquid crystal display device 30A of the first embodiment includes a liquid crystal cell 10, a polarizing plate 1Aa (first polarizing plate), and another polarizing plate 1Ab (second polarizing plate). A polarizing plate) is superposed on one surface (first surface) of the liquid crystal cell 10, and the other polarizing plate 1Ab (second polarizing plate) is superposed on the other surface (second surface) of the liquid crystal cell 10. The second surface may also be referred to as an inner surface of the first surface. The polarizing plates 1Aa and 1Ab shown in FIG. 4 Except for the mold film 13 and the third protective film 3, the others are the same as those of the polarizing plate 1A shown in FIG. The polarizing plate 1Aa (first polarizing plate) is adhered to the first surface of the liquid crystal cell 10 via the adhesive layer 11. The polarizing plate 1Aa (first polarizing plate) has an adhesive layer 11 overlapping the first surface of the liquid crystal cell 10, a second protective film 9 overlapping the adhesive layer 11, a polarizing sheet 7 overlapping the second protective film 9, and First protective film 5 of the polarizer 7. The other polarizing plate 1Ab (second polarizing plate) is attached to the second surface of the liquid crystal cell 10 via the adhesive layer 11. The other polarizing plate 1Ab (second polarizing plate) has an adhesive layer 11 overlapping the second surface of the liquid crystal cell 10, a second protective film 9 overlapping the adhesive layer 11, a polarizing sheet 7 overlapping the second protective film 9, and The first protective film 5 is superposed on the polarizer 7. The liquid crystal cell 10 and the pair of polarizing plates 1Aa and 1Ab constitute a liquid crystal panel 20A. The liquid crystal panel 20A and other components such as a backlight (surface light source device) constitute a liquid crystal display device 30A. Other components of the backlight are omitted in FIG. 4.

(Second Embodiment)

The second embodiment of the present invention shown in Figs. 5 and 6 will be described below. In the second embodiment, the same mechanism as in the first embodiment is used to suppress cracks due to temperature changes in the notched portion of the polarizer. The following describes matters specific to the second embodiment (the differences between the first embodiment and the second embodiment). Among the matters not described below, the second embodiment is the same as the first embodiment.

The polarizing plate 1B of the second embodiment includes a third protective film 3, a first protective film 5, a polarizer 7, an adhesive layer 11, and a release film 13. First In the second embodiment, the first protective film 5 is closely adhered to one surface on both surfaces of the polarizer 7, and the third protective film 3 is overlapped on the first protective film 5. On the other surface of the polarizer 7, there is not the second protective film 9, but an adhesive layer 11 is directly adhered. That is, the adhesive layer 11 is sandwiched between the polarizer 7 and the release film 13. As described above, the polarizing plate 1B of the second embodiment is different from the polarizing plate 1A of the first embodiment in that it does not include the second protective film 9. In other words, only one surface of the polarizer 7 included in the polarizing plate 1B of the second embodiment is protected by the first protective film 5 (protective layer), and the other surface of the polarizer 7 is not protected by the first protective film 5 Protective layer). Generally speaking, compared with a polarizer protected by a protective film (protective layer) on both surfaces, a polarizer protected by a protective film (protective layer) on only one side is cracked by a temperature change. The notch is easily formed. However, in the second embodiment, similarly to the first embodiment, since the reference line L is not orthogonal to the absorption axis A, the formation of cracks 7cr in the notch 7C can be suppressed. In addition, in the second embodiment, as in the first embodiment, since the direction E in which the cutout portion 7C extends is not parallel to the absorption axis A, it is easy to suppress the formation of cracks 7cr in the cutout portion 7C.

As shown in FIG. 6, the liquid crystal display device 30B of the second embodiment includes a liquid crystal cell 10, a polarizing plate 1Ba (first polarizing plate), and another polarizing plate 1Bb (second polarizing plate). The polarizing plate 1Ba (first A polarizing plate) is superposed on one surface (first surface) of the liquid crystal cell 10, and the other polarizing plate 1Bb (second polarizing plate) is superposed on the other surface (second surface) of the liquid crystal cell 10. The polarizing plates 1Ba and 1Bb shown in FIG. 6 are the same as the polarizing plates shown in FIG. 5 except that the release film 13 and the third protective film 3 are not provided. 1B is the same. The polarizing plate 1Ba (first polarizing plate) is attached to the first surface of the liquid crystal cell 10 via the adhesive layer 11. The polarizing plate 1Ba (first polarizing plate) has an adhesive layer 11 overlapping the first surface of the liquid crystal cell 10, a polarizing plate 7 overlapping the adhesive layer 11, and a first protective film 5 overlapping the polarizing plate 7. The other polarizing plate 1Bb (second polarizing plate) is attached to the second surface of the liquid crystal cell 10 via the adhesive layer 11. The other polarizing plate 1Bb (second polarizing plate) has an adhesive layer 11 overlapping the second surface of the liquid crystal cell 10, a polarizing plate 7 overlapping the adhesive layer 11, and a first protective film 5 overlapping the polarizing plate 7. The liquid crystal cell 10 and the pair of polarizing plates 1Ba and 1Bb constitute a liquid crystal panel 20B. The liquid crystal panel 20B and other components such as a backlight (surface light source device) constitute a liquid crystal display device 30B. Other components of the backlight are omitted in FIG. 6.

(Other embodiments)

The first and second embodiments of the present invention have been described above, but the present invention is not limited to the above-mentioned embodiments.

For example, as long as the reference line L connecting one diagonal portion at both ends of each notch portion is not orthogonal to the absorption axis A of the polarizer, a plurality of notch portions may be formed in the polarizing plate.

The shapes of the polarizing plate and the notch can take various forms depending on the application. For example, as shown in (a) of FIG. 7, the width of the notch portion 7C in a direction parallel to the reference line L may be greater than the depth of the notch portion in a direction perpendicular to the reference line L. As shown in FIG. 7 (b), the shape of the cutout portion 7C may be a semicircle. As shown in FIG. 7 (c), the shape of the cutout portion 7C may be a triangle. The shape of the notch 7C may be a quadrangle and Polygons other than triangles. Each shape of (a) in FIG. 7, (b) in FIG. 7, and (c) in FIG. 7 can be regarded as the shape of a polarizing plate provided with each polarizer 7. In other words, the shape of the notch portion 7C of each of the polarizers 7 shown in (a) in FIG. 7, (b) in FIG. 7, and (c) in FIG. 7 can be regarded as being formed in The shape of the notch portion of the polarizing plate of the polarizer 7.

As shown in FIG. 8 (a), the outer edges (the first end portion 7 e and the second end portion 17 e) of the polarizer 7 may be circular. As shown in FIG. 8 (b), a chamfered part 7C3 and a chamfered part 7C4 may be formed in a deep part (corner part) of the cutout part 7C. The diagonal portions 7C1 and 7C2 located at one of the two ends of the notch portion 7C may form truncated corners. When the diagonal portions 7C1 and 7C2 located at one of the two ends of the notch portion 7C form a truncated angle, the reference line L may be referred to as a straight line contacting the corner portion 7C1 and the corner portion 7C1. The outer corner portion CR1, the outer corner portion CR2, the outer corner portion CR3, and the outer corner portion CR4 located on the outer edge of the polarizer 7 may also form a truncated corner. The truncated angle can be formed by, for example, cutting and grinding the notch portion and the outer edge using an end mill. Each shape of (a) in FIG. 8, (b) in FIG. 8, and (c) in FIG. 8 can be regarded as the shape of a polarizing plate provided with each of the polarizers 7. In other words, the shape of the notch portion 7C of each of the polarizers 7 shown in (a) in FIG. 8, (b) in FIG. 8, and (c) in FIG. 8 can be considered as being formed in The shape of the notch portion of the polarizing plate of the polarizer 7. As shown in FIG. 13, a truncated corner portion 7C3 may be formed in a deep portion (the deepest portion in the depth) of the triangular notch portion 7C. The shape of the notch portion 7C formed in the polarizer 7 shown in FIG. 13 can be considered as the shape of the notch portion formed in the polarizing plate provided with the polarizer 7. (B) in Figure 8 and As shown in FIG. 13, by forming a truncated angle at the deep portion of the notched portion 7C, cracks in the notched portion 7C can be easily suppressed. The chamfered portion 7C3 and the chamfered portion 7C4 shown in (b) in FIG. 8 may be referred to as a curved deep portion (corner portion) of the cutout portion. The larger the curvature radius of the curved deep portion (corner portion) of the notched portion 7C, the easier it is to suppress cracks in the notched portion 7C. For example, by setting the curvature radius of the curved deep portion (corner portion) of the cutout portion 7C to be 0.07 mm or more, cracks in the cutout portion 7C can be easily suppressed. The curvature radius of the curved deep portion (corner portion) of the notch portion 7C is, for example, 0.07 mm or more and 30 mm or less, or 0.07 mm or more and 10 mm or less, and preferably 0.09 mm or more and 30 mm or less and 0.09 mm or more and 10 mm or less.

A part of the outer edge of the polarizer may be linear, and the remaining part of the outer edge of the polarizer may be curved. A part of the first end portion of the polarizer may be linear, and the remaining portion of the first end portion of the polarizer may be curved. The first end portion of the polarizer may be composed of only one or more straight lines (one or more sides). The first end portion of the polarizer may be composed of only a curve. A part of the second end portion of the polarizer may be linear, and the remaining portion of the second end portion of the polarizer may be curved. The second end portion of the polarizer may be composed of only one or more straight lines (one or more sides). The second end portion of the polarizer may be composed of only a curve. Each shape of the polarizer and the polarizer may be a polygon other than a quadrangle. Each shape of the polarizer and the polarizer may be, for example, an oval shape. Each shape of each optical film (3, 5, 9, 13) may be substantially the same as the shape of the polarizer 7.

As shown in FIG. 9, the first end portion 7 e in which the cutout portion 7C is formed may not be parallel to the second end portion 17 e. As shown in Figure 9, when the first end When the portion 7e is not parallel to the second end portion 17e, and the deep portion 7Cd (bottom) of the notched portion 7C is linear, the "direction E in which the notched portion 7C extends" can be defined as the one connecting the pair of corner portions 7C1 and 7C2 The line segment S is divided into halves, and is parallel to a straight line that divides the straight deep portion 7Cd of the cutout portion 7C into halves. When a pair of corner portions 7C1 and 7C2 form a truncated corner, the line segment S may be a line segment that contacts both of the pair of corner portions 7C1 and 7C2. As shown in FIG. 10, when the first end portion 7e is not parallel to the second end portion 17e and the deep portion 7Cd of the notch portion 7C is curved, "the direction E in which the notch portion 7C extends" can be defined as a connection The direction in which the straight line of the deep part 7Cd (deepest part) of the notch part 7C and the midpoint Sc of the line segment S is parallel. When the deep portion 7Cd of the curved notch portion 7C is divided into a plurality, the “direction E in which the notch portion 7C extends” can be defined as each of the plurality of deep portions (deepest portions) connecting the notch portion 7C and the middle of the line segment S. Point Sc is parallel to the straight line. By making each direction E corresponding to a plurality of deep portions (deepest portions) corresponding to the notch portion 7C not parallel to the absorption axis A, cracks in each deep portion can be suppressed.

There is no particular limitation on the type, number, and order of lamination of the optical films constituting the polarizing plate. For example, a modified example of the polarizing plate of the second embodiment may include a third protective film 3, a polarizer 7, a second protective film 9, an adhesive layer 11, and a release film 13. On one of the two surfaces of the polarizer 7, a third protective film 3 is not adhered to the first protective film 5. A second protective film 9 may be adhered to the other surface of the polarizer 7, and a release film 13 may be superposed on the second protective film 9 via the adhesive layer 11. As described above, the modified example of the polarizing plate of the second embodiment is different from the polarizing plate 1B of the second embodiment in that the first protective film 5 is not provided but the second protection is provided. Film 9.

The number of optical films included in the polarizing plate may be one. For example, the modification of the polarizing plate 1A shown in FIG. 1 may not include both the first protective film 5 and the second protective film 9. For example, either or both of the polarizing plate 1Aa (the first polarizing plate) and the polarizing plate 1Ab (the second polarizing plate) shown in FIG. 4 may not include the first protective film 5 and / or the second protective film 9 .

The polarizing plate 1A may not include one or both of the third protective film 3 and the release film 13. For example, the third protective film 3 can be peeled and removed from the polarizing plate 1A during the manufacturing process of the image display device. That is, the third protective film 3 may be a temporary protective film. The release film 13 may be peeled and removed from the polarizing plate 1A during the manufacturing process of the image display device.

It is also possible to directly superimpose a thin protective layer on the polarizer to replace the first protective film 5 or the second protective film 9. For example, when a coating film containing an active energy ray-curable resin is formed on the surface of a polarizer, and the coating film is hardened by irradiation with an active energy ray, a thinner protective layer than the previous protective film can be directly formed on The surface of the polarizer. In other words, a thin protective layer can be formed from the active energy ray-curable resin itself used after the polarizer and the protective film are adhered.

The release film may be disposed on both sides of the polarizing plate through an adhesive layer.

The optical film included in the polarizing plate can be a reflective polarizing film, a film with anti-glare function, a film with anti-surface reflection function, a reflective film, a transflective reflective film, a viewing angle compensation film, an optical compensation layer, and a touch screen. Sensor layer, anti-charge layer or anti-fouling layer.

The polarizing plate may further include a hard coating layer. For example, as shown in Figure 1 In a modified example of the polarizing plate 1A, the first protective film 5 may be located between the hard coating layer and the polarizer 7, and the hard coating layer may be located between the first protective film 5 and the third protective film 3. At this time, the first protective film 5 may contain cellulose triacetate.

The hard coat layer is, for example, a layer made of an acrylic resin film having a fine uneven shape on the surface. The hard coat layer can be formed of, for example, a coating film containing organic fine particles or inorganic fine particles. A method (for example, embossing method) can be used in which this coating film is pressed against a roller having an uneven shape. After forming a coating film containing no organic fine particles or inorganic fine particles, a method of pressing the coating film against a roller having an uneven shape may be used. The inorganic fine particles can be, for example, silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate, and the like. The organic fine particles (resin particles) may be, for example, crosslinked polyacrylic particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethylmethacrylate particles, or polysiloxane Resin particles, polyimide particles, etc. The binder component for dispersing the inorganic fine particles or the organic fine particles may be selected from materials with high hardness (hard coating). The binder component may be, for example, an ultraviolet curable resin, a thermosetting resin, an electron beam curable resin, or the like. From the viewpoints of productivity and hardness, it is preferable to use an ultraviolet curable resin in terms of an adhesive component. The thickness of the hard coat layer is, for example, 2 μm or more and 30 μm or less, or 3 μm or more and 30 μm or less.

[Example]

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples.

(Example 1)

A rectangular first laminated body composed of a polarizer film (polarizer 7 before cutting), four optical films (3, 5, 9, 13) and a pressure-sensitive adhesive layer 11 was produced. The first laminated body includes a release film 13, an adhesive layer 11 overlapping the release film 13, a second protective film 9 overlapping the adhesive layer 11, a polarizer film (7) overlapping the second protective film 9, and The first protective film 5 of the polarizer film (7) and the third protective film 3 overlapping the first protective film 5. The polarizer film (7) uses a stretched and dyed film-like polyvinyl alcohol. The first protective film 5 is a cellulose triacetate (TAC) film. The second protective film 9 is a film made of a cyclic olefin polymer-based resin (COP resin). As the third protective film 3, a PET protective film is used. As the release film 13, a PET separation film is used. The release film 13 has a thickness of 38 μm. The thickness of the adhesive layer 11 is 20 μm. The thickness of the second protective film 9 is 13 μm. The thickness of the polarizer 7 is 7 μm. The thickness of the first protective film 5 is 25 μm. The thickness of the third protective film 3 is 58 μm.

The above-mentioned first laminated body was cut by a cutter to produce a second laminated body having a length of 170 mm on the lateral side and a length of 100 mm on the longitudinal side. When cutting the first laminated body, by adjusting the cutting direction of the first laminated body, the angle θ formed by the lateral edge (first end portion) of the second laminated body and the absorption axis A of the polarizer 7 is adjusted. It is the angle described in the following Table 1. The absorption axis A of the polarizer 7 is parallel to the stretching direction of the polarizer film (7).

The second laminated body is fixed by being adsorbed on a supporting platform. A CO ₂ laser is irradiated on the outer edge of the fixed second laminated body to form a concave notch portion on the lateral side (first end portion) of the second laminated body. Through the above steps, the polarizing plate of Example 1 was obtained. The output of the CO ₂ laser is set at 20W. The oscillation wavelength of CO ₂ laser is 10.4 μm.

The shape of the obtained polarizing plate is the same as that of the polarizing plate 7 shown in (c) of FIG. 8. That is, the polarizing plate 7 shown in (c) in FIG. 8 is a polarizing plate provided in the polarizing plate produced by the above steps. The shape of the notch portion 7C formed at the first end portion 7e (the lateral side of the second laminated body) of the polarizer 7 is substantially semicircular. When the reference line L is defined as a straight line connecting the corner portions 7C1 and 7C2 located at both ends of the notch portion 7C, the angle formed by the reference line L and the absorption axis A is equal to the above-mentioned angle θ. The width Wc of the notch portion 7C in the direction parallel to the reference line L is 20 mm. That is, the distance between the corner portion 7C1 and the corner portion 7C2 is 20 mm. The depth of the notch portion 7C in the direction perpendicular to the reference line L is 10 mm. The width W of the first end portion 7e of the polarizer 7 in which the cutout portion 7C is formed is 150 mm. That is, the length of the lateral side of the polarizing plate (the width W of the polarizing plate) is 150 mm. The length of the vertical side of the polarizing plate (the vertical width of the polarizing plate) was 80 mm. Wc / W is 20mm / 150mm, which is 0.13.

The release film 13 is peeled from the adhesive layer 11 of the polarizing plate, and the polarizing plate is bonded to the glass plate through the adhesive layer 11. The third protective film 3 is peeled from the polarizing plate. Through this step, a sample composed of a glass plate and a polarizing plate bonded to the glass plate is prepared. Use this sample for thermal cycling tests. In the thermal cycle test, a cycle consisting of the following step 1 and step 2 following step 1 is repeated.

Step 1: A step of heating the sample in an environment of 85 ° C for 30 minutes.

Step 2: A step of cooling the sample in an environment of -40 ° C for 30 minutes.

After repeating a predetermined number of times shown in the following Table 1, At each point in the cycle, the notch 7C formed in the polarizer 7 included in the sample is observed with an optical microscope.

(Examples 2 to 8, Comparative Example 1)

The angle θ formed by the lateral side (first end portion) of the second laminated body and the absorption axis A of the polarizer 7 was adjusted to the angle described in the following Table 1, except that it was the same as in Example 1. In this way, each of the polarizing plates of Examples 2 to 8 and Comparative Example 1 was individually produced. That is, in the production of each of the polarizing plates of Examples 2 to 8 and Comparative Example 1, the angle θ formed by the reference line L and the absorption axis A was adjusted to the angle described in the following Table 1. As in Example 1, each of the polarizing plates of Examples 2 to 8 and Comparative Example 1 was used for a thermal cycle test.

The results of the respective thermal cycle tests of Examples 1 to 8 and Comparative Example 1 are shown in Table 1 below. “A” in the table means that the notch 7C of the polarizer 7 is not cracked. “B” means that a minute crack is formed in the cutout portion 7C of the polarizer 7. “C” means that the notch 7C of the polarizer 7 has a larger crack than “B”. “B” described in the column of Comparative Example 1 means that cracks having a length of about 1 mm were formed. "B" described in the row of Example 1 means that a crack having a length of about 10 mm was formed.

(Examples 9, 10, and Comparative Example 2)

Except that the shape and angle θ of the notch portion 7C were changed, each of the polarizing plates of Examples 9 and 10 and Comparative Example 2 was individually manufactured in the same manner as in Example 1.

The shapes of the respective polarizing plates of Examples 9, 10 and Comparative Example 2 are the same as those of the polarizing plate 7 shown in FIG. 13. That is, in Examples 9, 10, and Comparative Example 2, the shape of the notch portion 7C formed at the first end portion 7e (the lateral side of the second laminated body) of the polarizer 7 is almost triangular. The shapes of the respective polarizing plates of Examples 9, 10 and Comparative Example 2 are the same as those of the polarizing plate 7 shown in FIG. 13. In Examples 9, 10 and Comparative Example 2, the angle θ is adjusted to a value described in the following Table 2.

In Examples 9, 10 and Comparative Example 2, the width Wc of the notch portion 7C in the direction parallel to the reference line L was 20 mm. That is, the distance between the corner portion 7C1 and the corner portion 7C2 is 20 mm. In Examples 9, 10 and Comparative Example 2, the length Dc (depth) of the notch portion 7C in the direction perpendicular to the reference line L was 10 mm. In Examples 9, 10 and Comparative Example 2, a chamfered portion 7C3 was formed in a deep portion (corner portion) of the notched portion 7C. The radius of curvature of the chamfered portion 7C3 of the notched portion 7C is 0.1 mm. In Examples 9, 10, and Comparative Example 2, the width W of the first end portion 7e of the polarizer 7 having the cutout portion 7C was 150 mm. That is, the length of the lateral side of the polarizing plate (the width W of the polarizing plate) is 150 mm. In Examples 9, 10 and Comparative Example 2, the length of the vertical side of the polarizing plate (the vertical width of the polarizing plate) was 80 mm. Wc / W is 20mm / 150mm, which is 0.13.

As in Example 1, each of the polarizing plates of Examples 9, 10 and Comparative Example 2 was used for a thermal cycle test. The results of the respective thermal cycle tests of Examples 9, 10 and Comparative Example 2 are shown in Table 2 below.

(Examples 11 to 17)

In the production of each of the polarizing plates of Examples 11 to 17, the angle θ was adjusted to 45 °.

The shapes of the polarizing plates of Examples 11 to 17 are the same as those of the polarizing plate 7 shown in FIG. 13. That is, in Examples 11 to 17, the shape of the notch portion 7C formed at the first end portion 7e (the lateral side of the second laminated body) of the polarizer 7 is almost triangular. The shapes of the polarizing plates of Examples 11 to 17 are the same as those of the polarizing plate 7 shown in FIG. 13.

In Examples 11 to 17, the width W of the first end portion 7e of the polarizer 7 in which the cutout portion 7C was formed was adjusted to a value shown in the following Table 3. The width W may also be referred to as the length of the lateral sides of the polarizing plate (the width of the polarizing plate).

In Examples 11 to 17, the width Wc of the notch portion 7C in the direction parallel to the reference line L was 20 mm. That is, the distance between the corner portion 7C1 and the corner portion 7C2 is 20 mm. In Examples 11 to 17, Wc / W is a value shown in Table 3 below. In Examples 11 to 17, the length Dc (depth) of the notch portion 7C in the direction perpendicular to the reference line L was 10 mm. In Examples 11 to 17, a chamfered portion 7C3 was formed in a deep portion (corner portion) of the notched portion 7C. The radius of curvature of the chamfered portion 7C3 of the notched portion 7C is 0.1 mm. In Examples 11 to 17, the length of the vertical side of the polarizing plate (the vertical width of the polarizing plate) was 70 mm.

Except for the above matters, each of the polarizing plates of Examples 11 to 17 was individually produced in the same manner as in Example 1.

As in Example 1, each of the polarizing plates of Examples 11 to 17 was used for a thermal cycle test. In each of the thermal cycle tests of Examples 11 to 17, the surface of one of the polarizers 7 was covered by a second protective film 9 (by a COP tree). The surface of the other side of the polarizer 7 is covered with a first protective film 5 (TAC film). The results of the thermal cycle tests of Examples 11 to 17 are shown in Table 3 below.

(Examples 18 to 20)

In the production of the first laminated body in Examples 18 to 20, the first protective film 5 (TAC film) was not used, but the third protective film 3 (PET protective film) was directly stacked on the polarizer 7.

In the production of each of the polarizing plates of Examples 18 to 20, the angle θ was adjusted to 45 °.

The shape of each of the polarizing plates of Examples 18 to 20 is the same as that of the polarizing plate 7 shown in FIG. 13. That is, in Examples 18 to 20, the shape of the notch portion 7C formed at the first end portion 7e (the lateral side of the second laminated body) of the polarizer 7 is almost triangular. The shape of each of the polarizing plates of Examples 18 to 20 is the same as that of the polarizing plate 7 shown in FIG. 13.

In Examples 18 to 20, the width W of the first end portion 7e of the polarizer 7 in which the cutout portion 7C was formed was adjusted to a value shown in the following Table 3. The width W may also be referred to as the length of the lateral sides of the polarizing plate (the width of the polarizing plate).

In Examples 18 to 20, the width Wc of the notch portion 7C in the direction parallel to the reference line L was 20 mm. That is, the distance between the corner portion 7C1 and the corner portion 7C2 is 20 mm. In Examples 18 to 20, Wc / W is a value shown in Table 3 below. In Examples 18 to 20, the length Dc (depth) of the notch portion 7C in the direction perpendicular to the reference line L was 10 mm. In Examples 18 to 20, a chamfered portion 7C3 was formed in a deep portion (corner portion) of the notched portion 7C. The radius of curvature of the chamfered portion 7C3 of the notched portion 7C is 0.1 mm. In Examples 18 to 20, the length of the vertical side of the polarizing plate (the vertical width of the polarizing plate) was 70 mm.

Except for the above matters, each of the polarizing plates of Examples 18 to 20 was individually produced in the same manner as in Example 1.

As in Example 1, each of the polarizing plates of Examples 18 to 20 was used for a thermal cycle test. As described above, each of the polarizing plates of Examples 18 to 20 does not include the first protective film 5 (TAC film). Therefore, in each of the thermal cycle tests of Examples 18 to 20, one surface of the polarizer 7 was covered with the second protective film 9 (a film made of a COP resin), but the other surface of the polarizer 7 was not It is covered with the first protective film 5 (TAC film), but is exposed. The results of the thermal cycle tests of Examples 18 to 20 are shown in Table 3 below.

(Examples 21 to 23, Comparative Example 3)

In the production of each of the polarizing plates of Examples 21 to 23 and Comparative Example 3, the angle θ was adjusted to 45 °.

The shapes of the polarizing plates of Examples 21 to 23 and Comparative Example 3 are the same as those of the polarizing plate 7 shown in FIG. 3 except that the width W of the entire polarizing plate 7 is longer than the vertical width D of the entire polarizing plate 7. The shape is the same.

The width W of the entire polarizer 7 may be referred to as the width of the entire polarizer 7 in a direction parallel to the reference line L. The width W of the entire polarizer 7 may also be referred to as the width of the entire polarizer 7 in a direction parallel to the first end portion 7e. In any of Examples 21 to 23 and Comparative Example 3, the width W of the entire polarizer 7 in a direction parallel to the reference line L was 170 mm. The vertical width D of the entire polarizer 7 may be referred to as the width of the entire polarizer 7 in a direction perpendicular to the reference line L. In any of Examples 21 to 23 and Comparative Example 3, the width D of the entire polarizer 7 in a direction perpendicular to the reference line L was 100 mm.

As shown in FIG. 3, in any of Examples 21 to 23 and Comparative Example 3, the shape of the notch portion 7C formed on the first end portion 7e (the lateral side of the second laminated body) of the polarizer 7 is rectangle. In Examples 21 to 23 and Comparative Example 3, the width Wc of the notch portion 7C in the direction parallel to the reference line L is a value shown in the following Table 4. In Examples 21 to 23 and Comparative Example 3, Wc / W is a value shown in Table 4 below. In each of Examples 21 to 23 and Comparative Example 3, the length Dc (depth) of the notch portion 7C in the direction perpendicular to the reference line L was 5 mm.

Except for the above matters, each of the polarizing plates of Examples 21 to 23 and Comparative Example 3 was individually produced in the same manner as in Example 1.

As in Example 1, each of the polarizing plates of Examples 21 to 23 and Comparative Example 3 was used for a thermal cycle test. In each of the thermal cycle tests of Examples 21 to 23 and Comparative Example 3, one surface of the polarizer 7 was covered with a second protective film 9 (a film made of a COP resin), and the other surface of the polarizer 7 Covered by the first protective film 5 (TAC film). The results of the thermal cycle tests of Examples 21 to 23 and Comparative Example 3 are shown in Table 4 below.

[Industrial applicability]

The polarizing plate of the present invention can be bonded to, for example, a liquid crystal cell or an organic EL device, and is suitable as an optical component constituting an image display device such as a liquid crystal television, an organic EL television, or a smart phone.

7‧‧‧ polarizer

7C‧‧‧Notch

7C1, 7C2 ‧‧‧ Corner

7e‧‧‧ end of the polarizer (first end)

17e‧‧‧Second end

A‧‧‧ Absorption axis

D‧‧‧ Length of the whole polarizer

Dc‧‧‧ Length of the notch

E‧‧‧ Direction of notch

L‧‧‧ baseline

Wc‧‧‧ width of notch

W‧‧‧ Overall width of polarizer

α‧‧‧ Angle formed by the direction E in which the notch extends and the absorption axis A of the polarizer

Claims (27)

A polarizing plate is provided with a film-shaped polarizer, and a concave notch is formed at an end of the polarizer. When the reference line L is defined as a straight line connecting a diagonal portion at both ends of the notch, the aforementioned The reference line L is not orthogonal to the absorption axis A of the polarizer, Wc is the width of the notch in the direction parallel to the reference line L, and W is the entire width of the polarizer in the direction parallel to the reference line L. Width, Wc / W is 0.05 or more and less than 1.0. The polarizing plate according to item 1 of the scope of patent application, wherein the polarizer has a first end portion and a second end portion located on an opposite side of the first end portion, and the notch portion is formed on the first end portion, The notch portion extends from the first end portion toward the second end portion, and a direction E in which the notch portion extends is not parallel to the absorption axis A of the polarizer. A polarizing plate is provided with a film-shaped polarizer. The polarizer has a first end portion and a second end portion located on an opposite side to the first end portion, and a concave notch portion is formed on the first end portion. The notch portion extends from the first end portion toward the second end portion. The direction E in which the notch portion extends is not parallel to the absorption axis A of the polarizer, Wc is the width of the notch portion in a direction parallel to the first end portion, and W is the width of the notch portion parallel to the first end portion. The width of the entire polarizer in the direction Wc / W is 0.05 or more and less than 1.0. The polarizing plate according to any one of claims 1 to 3, wherein the protective film or the protective layer is closely adhered to both surfaces of the polarizer. The polarizing plate as described in any one of claims 1 to 3, wherein, on both surfaces of the polarizer, a protective film or a protective layer is adhered to only one surface. The polarizing plate according to any one of claims 1 to 3, wherein a truncated corner portion is formed in a deep portion of the notch portion. The polarizing plate according to item 6 of the scope of patent application, wherein the radius of curvature of the truncated corner portion is 0.07 mm or more and 30 mm or less. The polarizing plate according to item 1 or 2 of the scope of patent application, wherein the angle θ formed by the reference line L and the absorption axis A of the polarizer is 0 ° or more and less than 90 °. The polarizing plate according to item 3 of the scope of patent application, wherein when the reference line L is defined as a straight line connecting a diagonal portion at both ends of the notch portion, the reference line L and the absorption axis A of the polarizer Formed The angle θ is 0 ° or more and less than 90 °. The polarizing plate according to item 1 or 2 of the scope of patent application, wherein an angle θ formed by the reference line L and the absorption axis A of the polarizer is 0 ° or more and 75 ° or less. The polarizing plate according to item 3 of the scope of patent application, wherein when the reference line L is defined as a straight line connecting a diagonal portion at both ends of the notch portion, the reference line L and the absorption axis A of the polarizer The formed angle θ is 0 ° or more and 75 ° or less. The polarizing plate according to item 1 of the scope of patent application, wherein the polarizer has a first end portion and a second end portion located on an opposite side of the first end portion, and the notch portion is formed on the first end portion, The notch portion extends from the first end portion toward the second end portion, and an angle α formed by a direction E in which the notch portion extends and an absorption axis A of the polarizer is greater than 0 ° and 90 ° or less. The polarizing plate according to item 2 or 3 of the scope of patent application, wherein an angle α formed by the direction E in which the notch portion extends and the absorption axis A of the polarizer is greater than 0 ° and 90 ° or less. The polarizing plate according to item 1 or 2 of the scope of patent application, wherein the aforementioned Wc / W is 0.10 or more and less than 1.0. The polarizing plate according to item 3 of the scope of patent application, wherein the Wc / W is 0.10 or more and less than 1.0. The polarizing plate according to item 1 or 2 of the scope of patent application, wherein the width Wc of the notch portion in a direction parallel to the reference line L is 2 mm or more and less than 600 mm in a direction parallel to the reference line L The width W of the entire polarizer is 30 mm to 600 mm, and the width Wc of the notch portion does not exceed the width W of the entire polarizer. The polarizing plate according to item 3 of the scope of patent application, wherein the width Wc of the notch portion in a direction parallel to the first end portion is 2 mm or more and less than 600 mm in a direction parallel to the first end portion The width W of the entire polarizer is 30 mm to 600 mm, and the width Wc of the notch portion does not exceed the width W of the entire polarizer. The polarizing plate according to item 1 or 2 of the scope of patent application, wherein the length Dc of the notch in a direction perpendicular to the reference line L is 1 mm or more and 30 mm or less. The polarizing plate as described in item 3 of the scope of patent application, wherein when the reference line L is defined as a straight line connecting a diagonal portion located at both ends of the notch portion, the notch in a direction perpendicular to the reference line L The length Dc of the part is 1 mm or more and 30 mm or less. The polarizing plate according to any one of claims 1 to 3, wherein the thickness of the polarizer is 1 μm or more and 10 μm or less. The polarizing plate according to item 4 of the scope of patent application, wherein at least one of the protective films or protective layers adhered to the protective films or protective layers on both surfaces of the polarizer contains cellulose triacetate. The polarizing plate according to item 4 of the scope of the patent application, wherein at least one of the protective film or the protective layer adhered to both surfaces of the polarizer includes a cyclic olefin polymer-based resin. The polarizing plate according to item 4 of the scope of patent application, wherein at least one of the protective film or the protective layer adhered to both surfaces of the polarizer includes a (meth) acrylic resin. An image display device includes the polarizing plate according to any one of claims 1 to 23 of the scope of patent application. A method for manufacturing a polarizing plate, comprising: a step of manufacturing a first laminated body including a polarizer film and at least one optical film superimposed on the polarizer film; processing the first laminated body to produce a polarized film having no polarized light; The process of forming the second laminated body of the first end portion where the absorption axis A of the sheet film is orthogonal, and the step of forming a concave notch portion at the first end portion; when the reference line L is defined as connecting the When a diagonal line at both ends is a straight line, Wc is the width of the notch in the direction parallel to the reference line L, and W is the width of the entire polarizer in the direction parallel to the reference line L. Wc / W is adjusted to 0.05 or more and less than 1.0. The method of manufacturing a polarizing plate as described in claim 25, wherein the second laminated body has a second end portion located on the opposite side of the first end portion, and the notch portion is removed from the first end portion. It extends toward the second end portion, and the direction E in which the notch portion extends is adjusted to a direction that is not parallel to the absorption axis A. A method for manufacturing a polarizing plate, comprising: a step of manufacturing a first laminated body including a polarizer film and at least one optical film superposed on the polarizer film; processing the first laminated body to produce a first end portion; A step of forming a second laminated body at a second end portion opposite to the first end portion, and a step of forming a concave notch portion at the first end portion; and removing the notch portion from the first end portion Extend toward the second end portion, and adjust the direction E in which the notch portion extends to a direction not parallel to the absorption axis A of the polarizer film, and Wc is a The width W is the width of the entire polarizer in a direction parallel to the first end portion, and Wc / W is adjusted to be 0.05 or more and less than 1.0.