TWI735579B - 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 polarizing plate, an image display device, and a manufacturing method of the polarizing plate.

The polarizing plate is one of the optical parts that constitute the image display device of LCD TVs, organic EL TVs or smart phones. The polarizing plate is provided with a film-shaped polarizer and an optical film (for example, a protective film) superimposed on the polarizer. Due to the design of the image display device, a cut-out portion is sometimes formed at the end of the polarizer. For example, in Patent Document 1 below, it is described that a notch is formed at the end of the polarizer as an injection port of the liquid crystal.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2000-155325 A

The polarizer will expand or contract with temperature changes. According to the research conducted by the inventors, it was found that the polarizer with temperature change Because of the shrinkage, cracks will be formed on the notch. Especially due to thermal shock (abrupt temperature changes), cracks are more likely to form.

The present invention was created in view of the above circumstances, and its purpose is to provide a polarizing plate that can suppress cracks caused by temperature changes on the notch of the polarizer, an image display device including the polarizing plate, and a method for manufacturing the polarizing plate .

The one-layer polarizing plate of the present invention is provided with a film-like 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 one of the opposite corners of the two ends of the notch When 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 entire width of the 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 located on the opposite side of the first end portion, the 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, the direction E in which the notch 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 extends and the absorption axis A of the polarizer may be greater than 0° and less than 90°.

One aspect of the manufacturing method of the polarizing plate of the present invention includes the steps of producing a first laminate including a polarizer film and at least one optical film superimposed on the polarizer film, and processing the first laminate to form The process of forming a second laminate having a first end that is not orthogonal to the absorption axis A of the polarizer film, and the process of forming a concave notch on the first end of the second laminate; Line L is defined as a straight line connecting one of the opposite corners of the notch, Wc is the width of the notch in the direction parallel to the reference line L, and W is the entire polarizer in the direction parallel to the reference line L Adjust the Wc/W to 0.05 or more and less than 1.0.

In one aspect of the manufacturing method of the polarizing plate of the present invention, the second laminate may have a second end located on the opposite side of the first end, and the notch may be directed from the first end to the second end Extend, and adjust the direction E in which the notch 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 extends and the absorption axis A of the polarizer film (polarizer) can be adjusted to be greater than 0° and less than 90°.

Another form of the polarizing plate of the present invention is provided with a film-shaped polarizer. The polarizer has a first end and a second end located on the opposite side of the first end. A concave notch is formed at the first end. , The notch extends from the first end to the second end, the direction E in which the notch extends is not parallel to the absorption axis A of the polarizer, Wc is the width of the notch in the direction parallel to the first end, W It is the width of the entire polarizer in the direction parallel to the first end, and Wc/W is 0.05 or more and less than 1.0. In other words, in the polarizing plate of other forms of the present invention, the angle α formed by the direction E in which the notch extends and the absorption axis A of the polarizer is greater than 0° and less than 90°.

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

In any of the above-mentioned aspects of the present invention, the protective film or the protective layer may be closely adhered to both surfaces of the polarizer.

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

The image display device in any of the above-mentioned aspects of the present invention includes the above-mentioned polarizing plate.

According to the present invention, there is provided a polarizing plate, an image display device including the polarizing plate, and a manufacturing method of the 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‧‧‧The third protective film

5‧‧‧The first protective film

7‧‧‧Polarizer

7C‧‧‧Notch

7C1, 7C2‧‧‧Located at one of the opposite corners of the notch 7C

7Cd‧‧‧The deep part of the notch part 7C

7C3, 7C4‧‧‧Cut off

7cr‧‧‧crack

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

9‧‧‧Second protective film

10‧‧‧LCD unit

11‧‧‧Adhesive layer

13‧‧‧Release film

17e‧‧‧Second end of polarizer

20A, 20B‧‧‧LCD panel

30A, 30B‧‧‧Liquid crystal display device (image display device)

A‧‧‧Absorption axis

E‧‧‧The direction in which the notch 7C extends

L‧‧‧Baseline

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

Sc‧‧‧The midpoint of the line segment S

θ‧‧‧The angle formed by the reference line L and the absorption axis A

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

Fig. 1 is a schematic perspective view of the polarizing plate of the first embodiment of the present invention.

(A) in Figure 2 is a plan view of the polarizer included in the polarizer shown in Figure 1, and (b) in Figure 2 is a modification of the polarizer shown in (a) in Figure 2 .

Fig. 3 is a plan view of the 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 the image display device (liquid crystal display device) according to the first embodiment of the present invention.

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

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

(A) in Fig. 7 is a plan view of the polarizer included in the polarizing plate of another embodiment of the present invention, and (b) in Fig. 7 is one of the polarizers included in the polarizing plate of another embodiment of the present invention In the top view, (c) in FIG. 7 is a top view of a polarizer included in a polarizing plate according to another embodiment of the present invention.

(A) in Fig. 8 is a plan view of the polarizer included in the polarizing plate of another embodiment of the present invention, and (b) in Fig. 8 is one of the polarizers included in the polarizing plate of another embodiment of the present invention The top view, (c) in FIG. 8 is a top view of the polarizer included in the polarizing plate of the embodiment of the present invention.

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

Fig. 10 is a plan view of a polarizer included 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 the polarizer included in the polarizer shown in Fig. 11.

Fig. 13 is a plan view of a polarizer included in a polarizing plate of a part of the embodiment of the present invention.

The following describes the preferred embodiments of the present invention with reference to the drawings. In the drawing, the same symbols are attached to the same components. 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 each coordinate axis are common in all figures.

(First Embodiment)

The first embodiment will be explained based on Fig. 1, Fig. 2(a), Fig. 2(b), and Fig. 3. The polarizing plate 1A of the first embodiment is provided with a film-like polarizer 7 and a plurality of optical films (3, 5, 9, 13) superimposed on the polarizer 7. The polarizer 7 and the plurality of optical films (3, 5, 9, 13) are all quadrangular. The so-called "optical film" means a film-like member (excluding the polarizer itself) that constitutes a polarizing plate. The 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 plural 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 has polarized light Sheet 7, first protective film 5, second protective film 9, third protective film 3, and release film 13. The polarizing plate 1A also has an adhesive layer 11 between the second protective film 9 and the release film 13. The first protective film 5 is stacked on one surface of the polarizer 7, and the second protective film 9 is stacked on the other surface of the polarizer 7. That is, protective films (protective layers) are closely adhered to both surfaces of the polarizer 7. The third protective film 3 overlaps 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 overlaps the second protective film 9 with the adhesive layer 11 interposed therebetween. In other words, the second protective film 9 is located between the polarizer 7 and the adhesive layer 11.

A concave cut-out portion 7C (concave cut-out portion) is formed on the end of the polarizer 7 (first end 7e). This notch 7C penetrates the polarizer 7 and the optical film (3, 5, 9, 13) in the stacking 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, on the end surface of the polarizer 1A, a concave notch common to all of the polarizer 7, the optical films (3, 5, 9, 13) and the adhesive layer 11 constituting the polarizer 1A is formed. The shape of the notch 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 of the polarizer 1A as viewed from the lamination direction. The shape of the notch portion of the polarizing plate 1A viewed from the stacking direction can also be regarded as the shape of the notch portion 7C of the polarizer 7 viewed from the stacking direction. Hereinafter, not only the notch portion 7C of the polarizer 7 but also the notch portion of the polarizing plate 1A including the notch portion 7C may also be referred to as "the notch portion 7C." The notch part 7C has a rectangular shape, for example.

The reference line L is defined as connecting the two at the gap 7C A straight line between the opposite corners 7C1 and 7C2 at one end. The reference line L may alternatively be referred to as a straight line connecting the pair of corner portions 7C1 and 7C2 in a direction perpendicular to the above-mentioned stacking 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 7C and the absorption axis A of the polarizer 7 is 0° or more and less than 90°. The so-called absorption axis A can be alternatively referred to as a straight line substantially parallel to the alignment direction of the polyvinyl alcohol (PVA) molecules in the polarizer 7, for example. The so-called absorption axis A, for example, can be alternatively referred to as a straight line substantially parallel to the alignment direction of the pigment molecules (such as polyiodine or organic dye) adsorbed on the polyvinyl alcohol on the polarizer 7. The most carbon atoms constituting a PVA molecule can be said to be bonded to each other by covalent bonds (C-C bonds) along the absorption axis A. On the other hand, in the direction substantially perpendicular to the absorption axis A, the PVA molecules are bonded to each other by cross-linking bonds between the cross-linking agent (for example, boric acid). In other words, in the direction substantially perpendicular to the absorption axis A, the hydroxyl group of each PVA molecule forms a hydrogen bond or an oxygen-boron bond (O-B bond) with the boric acid located between the PVA molecules, thereby cross-linking 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 the direction substantially perpendicular to the absorption axis A. Therefore, the mechanical strength of the polarizer 7 in the direction substantially parallel to the absorption axis A is greater, so that the mechanical strength of the polarizer 7 in the direction perpendicular to the absorption axis A is high. In other words, the thermal shrinkage of the polarizer 7 in the direction substantially parallel to the absorption axis A is less likely to cause cracks than the thermal shrinkage of the polarizer 7 in the direction substantially perpendicular to the absorption axis A.

As shown in Figs. 11 and 12, the previous polarizing plate 1C, 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 crosslink bond is formed compared with the C-C bond in the PVA molecule. Therefore, when the reference line L is orthogonal to the absorption axis A, when the deep part (depth part) of the notch part 7C shrinks in a direction substantially parallel to the reference line L, a crack 7cr is likely to occur in the deep part of the notch part 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-linking bond between PVA molecules, the stronger C-C bond in the PVA molecule can increase the mechanical strength of the polarizer 7 in the direction parallel to the reference line L. As a result, even if the deep part of the notch 7C shrinks in the direction substantially parallel to the reference line L, the crack 7cr is less likely to occur in the deep part of the notch 7C. Especially when the reference line L is parallel to the absorption axis A (when the angle θ is 0°), most of the C-C bonds in 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 the 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 is, the harder it is to form a crack 7cr in the notch 7C. The angle θ is 0° or more and 75° or less or 0° or more and 60° or less.

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

The direction E in which the notch 7C extends is not parallel to the absorption axis A of the polarizer 7. Compared with the cross-linked bonds between PVA molecules, the CC bonds in the stronger PVA molecules can increase the direction perpendicular to the direction E The mechanical strength of the polarizer 7 above. As a result, even if the deep part of the notch 7C shrinks in the direction substantially perpendicular to the direction E, the crack 7cr is less likely to occur in the deep part of the notch 7C. The larger the angle α formed by the direction E and the absorption axis A, the less likely it is to form a crack 7cr on the notch 7C. Especially when the direction E is perpendicular to the absorption axis A (when the angle α is 90°), most of the C-C bonds in 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 significantly improved, and the formation of cracks 7cr in the notch 7C is significantly suppressed.

The width Wc of the notch 7C in the direction parallel to the reference line L can 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 7C in the direction parallel to the end (first end 7e) of the polarizer 7, and the overall width W of the polarizer 7 in the 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 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 overall width of the polarizer 7 in the direction parallel to the first end 7e. The width Wc of the notch 7C may be less than the width W of the entire polarizer 7, for example. When the width Wc of the notch 7C is 5 mm or more and 30 mm or less, the overall width W of the polarizer 7 (the overall width of the polarizing plate 1A) is greater than 20 mm and 160 mm or less, preferably greater than 25 mm and 130 mm or less, particularly It is more than 30mm and less than 100mm, more preferably more than 30mm and less than 70mm (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 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 0.05 or more and 0.90 or less, 0.05 or more and 0.80 or less, 0.05 or more and 0.78 or less, or 0.05 or more and 0.45 or less. The ratio Wc/W may alternatively be referred to as the 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 in the above range, it is easy to suppress cracks in the notch 7C. The reason for this is as follows. The smaller the width Wc of the notch 7C is than the width W of the entire polarizer 7, the more likely the force of expanding the width Wc of the notch 7C is generated due to the shrinkage of the entire polarizer 7 with temperature changes, which makes the notch 7C easier. Cracking occurs. On the other hand, as Wc/W is larger (the width W of the entire polarizer 7 is smaller), the amount of shrinkage of the entire polarizer 7 with a temperature change decreases. 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 change in width W. Since the shrinkage of the entire polarizer 7 accompanying the temperature change is reduced, the force to expand the width Wc of the notch 7C is less likely to be generated, and it is easier to suppress cracks in the notch 7C.

The length Dc of the notch portion 7C in the direction perpendicular to the reference line L can be, for example, 1 mm or more and 30 mm or less. The length Dc may also be referred to as the depth of the notch portion 7C in the direction perpendicular to the reference line L. The length D of the entire polarizer 7 in the 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 polarizer 7 may be alternatively referred to as the length of the entire polarizer 1A in the 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 laminate (first laminate). The so-called long strip-shaped polarizer film is the polarizer 7 before being processed and formed. The absorption axis of the polarizer film may be the same as the absorption axis A of the polarizer 7 after forming. The so-called long strip-shaped optical film (3, 5, 9, 13) before processing and forming a plurality of optical film systems. In the subsequent processing steps, the first laminate is processed to produce a plurality of laminates (second laminates) having the desired size and shape. This second layered body, like the above-mentioned polarizer 1A, has a first end 7e that is not orthogonal to the absorption axis A of the polarizer film (polarizer 7) and a second end located on the opposite side of the first end 7e部17e. In the processing step, for example, the first laminated body may be cut in a direction not orthogonal to the absorption axis A of the polarizer film to form a first end not orthogonal to the absorption axis A. In the processing step, for example, the first laminated body can be cut by a knife edge to produce the second laminated body. In the processing step, for example, the second laminate can be produced by press processing of the first laminate. In the processing step, for example, the first laminated body can be cut by laser to produce the second laminated body. The laser is, for example, a CO ₂ laser or an excimer laser. In the processing step, for example, cutting using the above-mentioned blade, press processing, and cutting using a laser can be combined to produce the second laminate. After the first laminated body is processed by the above-mentioned processing method to adjust the size of the first laminated body to be larger than the predetermined size, the end of the first laminated body is cut and polished by a milling cutter to produce the second laminated body .

In the processing step, for example, punching or cutting with a knife or laser may be used to form the concave notch portion 7C at the first end portion 7e of the second laminate. When forming the notch 7C in the processing step, the notch 7C is extended from the first end 7e to the second end 17e, and the direction E in which the notch 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 notched portion 7C is formed, the end processing step may be performed. In the end processing step, for example, an end mill (endmill) can be used to cut and grind the end surface of the second laminated body including the notch 7C. The end mill is a type of milling cutter used for cutting. The end milling cutter cuts and grinds the end surface of the second laminated body including the notch portion 7C by, for example, a cutter located on a side surface substantially parallel to the rotation axis. As a result, the end surface of the second laminate including the notch 7C can be smoothly finished. By using this end mill, the second laminate can be molded into a polarizing plate 1A having a desired shape and size in a short time. It can also improve the polarizing plate 1A Productivity. In the processing step, a first layered body larger than the previous one is punched out to make a second layered body. In the subsequent end processing step, the end surface of the second layered body is cut and ground by an end mill. As a result, the margin of the end removed from the second laminate in the end processing step is reduced, the generation of impurities such as grinding chips in the end processing step is suppressed, and the incorporation of impurities into the product (polarized light) is suppressed. Plate 1A).

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

The direction of the absorption axis A of the polarizer 7 included in the second laminate 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 laminate is adjusted so that the angle formed by the first end 7e of the second laminate and the absorption axis A is adjusted to 0° or more and less than 90° Therefore, the angle θ formed by the reference line L and the absorption axis A can be freely controlled within the range of 0° or more and less than 90°. In addition, as described above, the notch 7C is formed in the first In the case of 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 of greater than 0° to 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 where the notch 7C is formed in the second laminate. The relative positional relationship between the direction E and the absorption axis A can be controlled by the position where the notch 7C is formed in the second laminate and the direction of the notch 7C. The direction of the absorption axis A in the polarizer film (polarizer 7) itself can be adjusted and controlled by the stretching direction and the 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 resin (PVA film) produced by processes such as stretching, dyeing, and crosslinking. The details of the polarizer 7 are as follows.

For example, first, the PVA film is stretched uniaxially or biaxially. The two-color ratio of the polarizer 7 stretched in a uniaxial direction tends to be higher. After stretching, dyeing solution is then used to dye the PVA film with iodine, dichroic dye (polyiodine) or organic dye. The dyeing solution may contain boric acid, zinc sulfate, and zinc chloride. The PVA film can be washed with water before dyeing. By washing with water, dirt and anti-blocking agent can be removed from the surface of the PVA film. In addition, the PVA film swells by washing with water, and as a result, staining spots (uneven dyeing) can be easily suppressed. For cross-linking, the dyed PVA film is treated with a solution of a cross-linking agent (for example, an aqueous solution of boric acid). After being treated with a crosslinking agent, the PVA film was washed with water and then dried. Through the above steps, the polarizer 7 can be obtained. The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. Polyvinyl acetate The ester resin may be, for example, polyvinyl acetate, which is a homopolymer of vinyl acetate, or a copolymer of vinyl acetate and other monomers (for example, ethylene-vinyl acetate copolymer). Other monomers copolymerized with vinyl acetate may be unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, or acrylamides with ammonium groups in addition to ethylene. The polyvinyl alcohol resin can be modified by aldehydes. The modified polyvinyl alcohol-based resin may be, for example, partially formalized polyvinyl alcohol, polyvinyl acetal, or polyvinyl butyral. The polyvinyl alcohol-based resin may be a polyolefin-based alignment film such as a dehydrated polyvinyl alcohol or a dehydrochloric acid-treated polyvinyl chloride. It can be dyed before stretching, or it can be 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 temperature changes, and to suppress the change in the size of the polarizer 7 itself. As a result, stress does not easily act on the polarizer 7 and it is easy to suppress cracks in the polarizer 7.

The first protective film 5 and the second protective film 9 may be optically transparent thermoplastic resins as long as they are light-transmitting thermoplastic resins. The resin constituting the first protective film 5 and the second protective film 9 may be, for example, chain polyolefin resin, cyclic olefin polymer resin (COP resin), cellulose ester resin, polyester resin, polycarbonate Ester resins, (meth)acrylic resins, polystyrene resins, or mixtures or copolymers of these. The composition of the first protective film 5 may be exactly the same as the composition of the second protective film 9. NS The composition of a protective film 5 can also be different from the composition of the second protective film 9.

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

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

The cellulose ester 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-based 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 polyvalent carboxylic acid or a derivative thereof and a polyvalent alcohol. The polycarboxylic acid or its derivative may be a dicarboxylic acid or its derivative. The polycarboxylic acid or its derivative may be, for example, terephthalic acid, isophthalic acid, dimethyl terephthalic acid, and dimethyl naphthalene dicarboxylate. The polyol may be, for example, a diol. The polyol may be, for example, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, or cyclohexanedimethanol.

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

The polycarbonate resin is a polymer in which a polymerized unit (monomer) is bonded via a carbonate group. The polycarbonate resin can be a modified polycarbonate with a modified polymer backbone, or a copolymerized polycarbonate.

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

The optical film sandwiching at least one of the pair of optical films (the first protective film 5 and the second protective film 9) of the polarizer 7 may contain triacetate cellulose (TAC). The optical film sandwiching at least one of the pair of optical films (the first protective film 5 and the second protective film 9) of the polarizer 7 may contain a cyclic olefin polymer resin (COP resin). The optical film sandwiching at least one of the pair of optical films (the first protective film 5 and the second protective film 9) of 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. Clamp one of the polarizers 7 to the optical film (the first protective film 5 and the second protective film The film of one of the films 9) may contain cellulose triacetate, and the film of the other of the optical films (the first protective film 5 and the second protective film 9) sandwiching one of the polarizers 7 may contain a ring Olefin polymer. The film sandwiching one of the pair of optical films (the first protective film 5 and the second protective film 9) of the polarizer 7 may contain cellulose triacetate, and the pair of optical films (the first protective film) The other film of the film 5 and the second protective film 9) may contain polymethyl methacrylate. The film sandwiching one of the pair of optical films (the first protective film 5 and the second protective film 9) of the polarizer 7 may contain a cyclic olefin polymer resin, and the pair of optical films ( The other film 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), since the optical film (protective film) adheres to the polarizer 7, the polarizer accompanying temperature changes can be suppressed The expansion or contraction of 7, so it is not easy to produce 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-based resin, cracks in the polarizer 7 are unlikely to occur.

The first protective film 5 or the second protective film 9 may contain at least one selected from the group consisting of lubricants, plasticizers, dispersants, heat stabilizers, ultraviolet absorbers, infrared absorbers, antistatic agents, and antioxidants. 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, 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 with optical functions such as a retardation film or a brightness enhancement film. For example, by stretching a film composed of the above-mentioned thermoplastic resin or forming a liquid crystal layer on the film, a retardation film provided with an arbitrary retardation value can be obtained.

The first protective film 5 can 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 may contain an active energy ray curable resin described later.

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

The active energy ray curable resin may be one type of resin or contain multiple types of resins. For example, the active energy ray curable resin may contain a cationically polymerizable curable compound or a radically polymerizable curable compound. The active energy ray curable resin may contain a cationic polymerization initiator or a radical polymerization initiator for starting the curing reaction of the above-mentioned curable compound.

The cationically polymerizable curable compound may be, for example, an epoxy compound (a compound having at least one epoxy group in the molecule) or an oxygen-based compound (a compound having at least one oxygen ring in the molecule). The radically polymerizable curable compound may be, for example, a (meth)acrylic compound (a compound having at least one (meth)acryloyloxy group in the molecule), and the radically polymerizable curable compound may be free Base polymerizability The double bond of the vinyl compound.

Active energy ray curable resin may optionally contain cationic polymerization accelerators, ion traps, antioxidants, chain transfer agents, adhesion imparting agents, thermoplastic resins, fillers, flow regulators, plasticizers, defoamers, and antistatic agents , Leveling agent, or solvent, etc.

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

The resin constituting the third protective film 3 may be the same as the above-mentioned resins exemplified 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 and 200 μm or less.

The resin constituting the release film 13 may be the same as the above-mentioned resins exemplified 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 and 200 μm or less.

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 overlapped on one surface (first surface) of the liquid crystal cell 10, and the other polarizing plate 1Ab (second polarizing plate) is overlapped on the other surface (second surface) of the liquid crystal cell 10. The second surface may also be referred to as the inner surface of the first surface. The polarizing plates 1Aa and 1Ab shown in Figure 4, except for the Except for the mold film 13 and the third protective film 3, the other parts are the same as the polarizing plate 1A shown in Fig. 1. The polarizing plate 1Aa (first polarizing plate) is attached 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 film 7 overlapping the second protective film 9 and The 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. Another 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 polarizer 7 overlapping the second protective film 9, and The first protective film 5 overlaps the polarizer 7. The liquid crystal cell 10 and the pair of polarizing plates 1Aa and 1Ab constitute a liquid crystal panel 20A. Other components such as the liquid crystal panel 20A and the backlight (surface light source device) constitute the liquid crystal display device 30A. Other components of the backlight are omitted in Figure 4.

(Second Embodiment)

The second embodiment of the present invention shown in Figs. 5 and 6 will be described below. The second embodiment also uses the same mechanism as the first embodiment to suppress cracks accompanying temperature changes in the notch portion of the polarizer. The following describes the inherent matters of the second embodiment (the difference between the first embodiment and the second embodiment). Among the items not explained below, the second embodiment and the first embodiment are common.

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. NS In the second embodiment, of the two surfaces of the polarizer 7, the first protective film 5 is closely adhered to one surface, and the third protective film 3 overlaps the first protective film 5. On the other surface of the polarizer 7, instead of the second protective film 9, the 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 the second protective film 9 is not provided. In other words, only one side 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 side of the polarizer 7 is not protected by the first protective film 5 ( Protective layer) is protected. Generally speaking, compared with a polarizer whose two surfaces are protected by a protective film (protective layer), in a polarizer whose only one side is protected by a protective film (protective layer), cracks caused by temperature changes The notch is easily formed. However, in the second embodiment, as in the first embodiment, since the reference line L is not orthogonal to the absorption axis A, the formation of the crack 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 notch 7C extends is not parallel to the absorption axis A, the formation of the crack 7cr in the notch 7C is easily suppressed.

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 polarizing plate) The polarizing plate) is overlapped on one surface (first surface) of the liquid crystal cell 10, and the other polarizing plate 1Bb (second polarizing plate) is overlapped 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 they do not have the release film 13 and the third protective film 3 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 overlapped on the first surface of the liquid crystal cell 10, a polarizer 7 overlapped on the adhesive layer 11, and a first protective film 5 overlapped on the polarizer 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 overlapped on the second surface of the liquid crystal cell 10, a polarizer 7 overlapped on the adhesive layer 11, and a first protective film 5 overlapped on the polarizer 7. The liquid crystal cell 10 and the pair of polarizing plates 1Ba and 1Bb constitute a liquid crystal panel 20B. Other components such as the liquid crystal panel 20B and the backlight (surface light source device) constitute the liquid crystal display device 30B. Other components of the backlight are omitted in Figure 6.

(Other embodiments)

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

For example, as long as the reference line L connecting one of the diagonals of the two ends of each notch is not orthogonal to the absorption axis A of the polarizer, a plurality of notches can be formed in the polarizer.

The respective shapes of the polarizing plate and the notch can take various forms depending on the application. For example, as shown in (a) of Figure 7, the width of the notch 7C in the direction parallel to the reference line L may be greater than the depth of the notch in the direction perpendicular to the reference line L. As shown in (b) of FIG. 7, the shape of the notch 7C may be a semicircle. As shown in (c) in FIG. 7, the shape of the notch 7C may be a triangle. The shape of the notch 7C can also be quadrangular and Polygons other than triangles. The shapes of the polarizer 7 shown in (a) in FIG. 7, (b) in FIG. 7, and (c) in FIG. In other words, the shape of the notch 7C of each polarizer 7 shown in (a) in FIG. 7, (b) in FIG. 7, and (c) in FIG. The shape of the notch of the polarizing plate of the polarizer 7.

As shown in (a) of FIG. 8, the outer edges (the first end portion 7e and the second end portion 17e) of the polarizer 7 may be circular. As shown in (b) of Fig. 8, a chamfered part 7C3 and a chamfered part 7C4 can be formed in the deep part (corner part) of the notch part 7C. One of the opposite corners 7C1 and 7C2 located at the two ends of the notch 7C may also form a truncated angle. When one of the two ends of the notch portion 7C forms a truncated angle at the corner portions 7C1 and 7C2, the reference line L can be referred to as a straight line contacting the corner portion 7C1 and the corner portion 7C1. The outer corners CR1, the outer corners CR2, the outer corners CR3, and the outer corners CR4 located on the outer edge of the polarizer 7 may also form truncated corners. The above-mentioned cut-off angle can be formed, for example, by cutting and grinding the notch and the outer edge using an end mill. The shapes of the polarizer 7 shown in (a) in FIG. 8, (b) in FIG. 8, and (c) in FIG. In other words, the shape of the notch 7C of each polarizer 7 shown in (a) in Figure 8, (b) in Figure 8, and (c) in Figure 8 can be regarded as being formed with The shape of the notch of the polarizing plate of the polarizer 7. As shown in Fig. 13, a truncated corner portion 7C3 can be formed in the deep portion (the deepest portion) of the triangular notch portion 7C. The shape of the notch portion 7C formed in the polarizer 7 shown in FIG. 13 can be regarded as the shape of the notch portion of the polarizer plate provided with the polarizer 7. As in Figure 8 (b) and As shown in FIG. 13, by forming a truncated angle at the deep portion of the notch 7C, it is possible to easily suppress cracks in the notch 7C. The truncated corner portion 7C3 and the truncated corner portion 7C4 shown in (b) in Fig. 8 may alternatively be referred to as the curved deep portion (corner portion) of the notch portion. The larger the radius of curvature of the curved deep portion (corner portion) of the notch portion 7C, the easier it is to suppress cracks in the notch portion 7C. For example, by making the curvature radius of the curved deep portion (corner portion) of the notch portion 7C to be 0.07 mm or more, cracks in the notch 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, preferably 0.09 mm or more and 30 mm or less, or 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. It may also be that a part of the first end of the polarizer is linear, and the remaining part of the first end of the polarizer is curvilinear. The first end of the polarizer may be composed of only one or more straight lines (more than one side). The first end of the polarizer can only be formed by a curved line. It is also possible that a part of the second end of the polarizer is linear, and the remaining part of the second end of the polarizer is curvilinear. The second end of the polarizer may be composed of only one or more straight lines (more than one side). The second end of the polarizer can be composed of only curved lines. 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 an ellipse, for example. The shapes of the optical films (3, 5, 9, 13) may be approximately the same as the shape of the polarizer 7.

As shown in Fig. 9, the first end 7e where the notch 7C is formed may not be parallel to the second end 17e. 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 notch 7C is linear, the "direction E in which the notch 7C extends" can be defined as connecting a pair of corners 7C1, 7C2 The line segment S is divided into two equal parts, and a direction parallel to the straight line 7Cd that divides the linear deep part of the notch part 7C into two equal parts. When the pair of corners 7C1 and 7C2 form a truncated angle, the line segment S may be a line segment contacting both of the pair of corners 7C1 and 7C2. As shown in Figure 10, when the first end 7e is not parallel to the second end 17e, and the deep portion 7Cd of the notch 7C is curved, the "direction E in which the notch 7C extends" can be defined as connecting with The direction in which the straight line between the deep part 7Cd (the deepest part) of the notch part 7C and the midpoint Sc of the line segment S is parallel. When the deep part 7Cd of the curvilinear notch 7C diverges into a plurality of divergences, the "direction E in which the notch 7C extends" can be defined as the middle of each of the plurality of deep parts (the deepest part) connecting the notch 7C and the line segment S Point Sc is the direction parallel to the straight line. By making each direction E corresponding to a plurality of deep portions (the deepest portion) of the notch portion 7C not parallel to the absorption axis A, cracks in each deep portion can be suppressed.

The type and number of optical films constituting the polarizing plate and the order of layering are not particularly limited. For example, a modification 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, not the first protective film 5, but the third protective film 3 is closely adhered. On the other surface of the polarizer 7, a second protective film 9 may be closely adhered, and on the second protective film 9, a release film 13 may be overlapped with an adhesive layer 11 interposed therebetween. As described above, the modification of the polarizing plate of the second embodiment is different from the polarizing plate 1B of the second embodiment in that it does not include the first protective film 5 but includes the second protective film. 膜9。 Film 9.

The number of optical films included in the polarizing plate can 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 (first polarizing plate) and the polarizing plate 1Ab (second polarizing plate) shown in FIG. 4 may not have 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 off 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 can also be peeled off and removed from the polarizing plate 1A during the manufacturing process of the image display device.

It is also possible to directly overlay a thinner 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 cured by the irradiation of the active energy ray, a protective layer thinner than the previous protective film can be directly formed on the surface of the polarizer. The surface of the polarizer. In other words, a thin protective layer can be formed from the active energy ray-curable resin itself used to bond the polarizer and the protective film.

The release film can be arranged on both sides of the polarizing plate through the adhesive layer.

The optical film of the polarizer can be reflective polarizing film, film with anti-glare function, film with anti-surface reflection function, reflective film, semi-transmissive reflective film, viewing angle compensation film, optical compensation layer, touch control Sensor layer, anti-charge layer or anti-fouling layer.

The polarizing plate can also have a hard coating. For example, as shown in Figure 1 In the modification of the polarizing plate 1A, the first protective film 5 may be located between the hard coat layer and the polarizer 7, and the hard coat 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 composed of an acrylic resin film provided with fine concavo-convex shapes on the surface. The hard coat layer may be formed of, for example, a coating film containing organic fine particles or inorganic fine particles. A method of pressing the coating film against a roller having a concave and convex shape (for example, an embossing method, etc.) can be used. It is also possible to use a method of pressing the coating film against a roller having a concave and convex shape after forming a coating film that does not contain organic particles or inorganic particles. The inorganic 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. In addition, the organic particles (resin particles) may be, for example, cross-linked polyacrylic acid particles, methyl methacrylate/styrene copolymer resin particles, cross-linked polystyrene particles, cross-linked polymethyl methacrylate particles, polysiloxanes Resin particles, polyimide particles, etc. The binder component used to disperse inorganic particles or organic particles can be selected from materials with high hardness (hard coating). The binder component may be, for example, ultraviolet curable resin, thermosetting resin, electron beam curable resin, or the like. From the viewpoints of productivity, hardness, etc., it is preferable to use an ultraviolet curable resin in terms of the binder 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]

The following examples illustrate the present invention in more detail, 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 laminate includes a release film 13, an adhesive layer 11 overlapped on the release film 13, a second protective film 9 overlapped on the adhesive layer 11, a polarizer film (7) overlapped on 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 stretched and dyed film-like polyvinyl alcohol. The first protective film 5 uses a triacetate cellulose (TAC) film. The second protective film 9 uses a film composed of a cyclic olefin polymer resin (COP resin). The third protective film 3 uses a PET protective film. As the release film 13, a PET separation film is used. The thickness of the release film 13 is 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 first laminated body was cut by a cutter to produce a second laminated body having a lateral side length of 170 mm and a longitudinal side length of 100 mm. When cutting the first laminate, adjust the cutting direction of the first laminate to adjust the angle θ formed by the lateral side (first end) of the second laminate and the absorption axis A of the polarizer 7 It is the angle described in Table 1 below. The absorption axis A of the polarizer 7 is parallel to the stretching direction of the polarizer film (7).

The second layered body is adsorbed on the mounting table and fixed. By _{irradiating CO 2} laser to the outer edge of the fixed second laminate, a concave notch is formed on the lateral side (first end) of the second laminate. After the above steps, the polarizing plate of Example 1 was obtained. The output of the CO ₂ laser is set at 20W. The CO ₂ laser has an oscillation wavelength of 10.4μm.

The shape of the obtained polarizer is the same as the shape of the polarizer 7 shown in (c) in FIG. 8. That is, the polarizer 7 shown in (c) in Fig. 8 is a polarizer included in the polarizer 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 laminate) of the polarizer 7 is substantially semicircular. When the reference line L is defined as a straight line connecting the corners 7C1 and 7C2 at both ends of the notch 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 7C in the direction parallel to the reference line L is 20 mm. That is, the distance between the corner 7C1 and the corner 7C2 is 20 mm. The depth of the notch 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 notch portion 7C is formed is 150 mm. That is, the length of the horizontal side of the polarizing plate (the horizontal 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) is 80mm. 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 attached to the glass plate through the adhesive layer 11. Furthermore, the third protective film 3 is peeled off from the polarizing plate. Through this step, a sample composed of a glass plate and a polarizing plate attached to the glass plate is prepared. Use this sample for thermal cycling test. In the thermal cycle test, the cycle consisting of the following step 1 and step 2 following step 1 is repeated.

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

Step 2: Cool down the sample for 30 minutes in an environment of -40°C.

Repeat the predetermined number of times shown in Table 1 below At each time point of the cycle, the notch portion 7C formed in the polarizer 7 provided in the sample was observed with an optical microscope.

(Examples 2-8, Comparative Example 1)

The angle θ formed by the lateral side (first end portion) of the second laminate 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. According to the method, the polarizing plates of Examples 2 to 8 and Comparative Example 1 were produced individually. That is, in the production 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 first table below. As in Example 1, each polarizing plate of Examples 2 to 8 and Comparative Example 1 was used to perform a thermal cycle test.

The results of each thermal cycle test of Examples 1 to 8 and Comparative Example 1 are shown in Table 1 below. "A" in the table means that no cracks have occurred in the notch 7C of the polarizer 7. "B" means that minute cracks are formed in the notch 7C of the polarizer 7. "C" means that a crack larger than "B" is formed in the notch 7C of the polarizer 7. The "B" described in the column of Comparative Example 1 means that a crack with a length of about 1 mm is formed. The "B" described in the row of Example 1 means that a crack with a length of about 10 mm is formed.

(Examples 9, 10, Comparative Example 2)

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

The shapes of the polarizing plates of Examples 9, 10 and Comparative Example 2 are the same as the shape 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 of the polarizer 7 (the lateral side of the second laminate) was almost triangular. The shapes of the polarizing plates of Examples 9, 10 and Comparative Example 2 are the same as the shape of the polarizing plate 7 shown in FIG. 13. In Examples 9, 10 and Comparative Example 2, the angle θ is adjusted to the value described in Table 2 below.

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 7C1 and the corner 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 is 10 mm. In Examples 9, 10 and Comparative Example 2, the cut-off portion 7C3 was formed in the deep portion (corner portion) of the notch portion 7C. The radius of curvature of the truncated corner portion 7C3 of the notch 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 with the notch portion 7C formed was 150 mm. That is, the length of the horizontal side of the polarizing plate (the horizontal 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 polarizing plate of Examples 9, 10 and Comparative Example 2 was used to perform a thermal cycle test. The results of each thermal cycle test of Examples 9, 10 and Comparative Example 2 are shown in Table 2 below.

(Examples 11~17)

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

The shapes of the polarizing plates in Examples 11 to 17 are the same as the shape of the polarizing plate 7 shown in FIG. 13. That is, in Examples 11 to 17, the shape of the notch 7C formed at the first end 7e of the polarizer 7 (the lateral side of the second laminate) was almost triangular. The shapes of the polarizing plates in Examples 11 to 17 are the same as the shape 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 notch portion 7C was formed was adjusted to the value shown in Table 3 below. The width W may also be referred to as the length of the horizontal side of the polarizing plate (the horizontal 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 7C1 and the corner 7C2 is 20 mm. In Examples 11 to 17, Wc/W is the 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, the truncated portion 7C3 was formed in the deep portion (corner portion) of the notch portion 7C. The radius of curvature of the truncated corner portion 7C3 of the notch 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, the polarizing plates of Examples 11 to 17 were individually produced in the same manner as in Example 1.

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

(Examples 18-20)

In the production of the first laminate of 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 superimposed on the polarizer 7.

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

The shapes of the polarizing plates in Examples 18 to 20 are the same as the shape of the polarizing plate 7 shown in FIG. 13. That is, in Examples 18 to 20, the shape of the notch 7C formed at the first end 7e of the polarizer 7 (the lateral side of the second laminate) was almost triangular. The shapes of the polarizing plates in Examples 18 to 20 are the same as the shape 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 notch portion 7C was formed was adjusted to the value shown in Table 3 below. The width W may also be referred to as the length of the horizontal side of the polarizing plate (the horizontal width of the polarizing plate).

In Examples 18 to 20, the width Wc of the notch 7C in the direction parallel to the reference line L was 20 mm. That is, the distance between the corner 7C1 and the corner 7C2 is 20 mm. In Examples 18 to 20, Wc/W is the 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, the truncated portion 7C3 was formed in the deep portion (corner portion) of the notch portion 7C. The radius of curvature of the truncated corner portion 7C3 of the notch 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, the polarizing plates of Examples 18 to 20 were individually produced by the same method as Example 1.

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

(Examples 21-23, Comparative Example 3)

In the production 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 similar to those of the polarizer 7 shown in Fig. 3 except that the horizontal width W of the entire polarizer 7 is longer than the vertical width D of the entire polarizer 7 The shape is the same.

The horizontal width W of the entire polarizer 7 may be alternatively referred to as the width of the entire polarizer 7 in the 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 7e. In any of Examples 21 to 23 and Comparative Example 3, the overall width W of the polarizer 7 in the direction parallel to the reference line L is 170 mm. The vertical width D of the entire polarizer 7 may be alternatively referred to as the width of the entire polarizer 7 in the 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 the direction perpendicular to the reference line L is 100 mm.

As shown in Figure 3, in any of Examples 21 to 23 and Comparative Example 3, the shape of the notch portion 7C formed at the first end portion 7e of the polarizer 7 (the lateral side of the second laminate) 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 the value shown in Table 4 below. In Examples 21 to 23 and Comparative Example 3, Wc/W is the value shown in Table 4 below. The length Dc (depth) of the notch portion 7C in the direction perpendicular to the reference line L in any of Examples 21 to 23 and Comparative Example 3 is 5 mm.

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

As in Example 1, each polarizing plate of Examples 21 to 23 and Comparative Example 3 was used to perform a thermal cycle test. In each thermal cycle test of Examples 21 to 23 and Comparative Example 3, the surface of one side of the polarizer 7 was covered by the second protective film 9 (film made of COP-based resin), and the surface of the other side of the polarizer 7 Covered by the first protective film 5 (TAC film). The results of each thermal cycle test 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 attached to a liquid crystal cell or an organic EL device, for example, and is suitable for use as an optical component constituting an image display device such as a liquid crystal TV, an organic EL TV, or a smartphone.

7‧‧‧Polarizer

7C‧‧‧Notch

7C1、7C2‧‧‧Corner

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

17e‧‧‧Second end

A‧‧‧Absorption axis

D‧‧‧The length of the entire polarizer

Dc‧‧‧The length of the notch

E‧‧‧The direction in which the notch extends

L‧‧‧Baseline

Wc‧‧‧Width of notch

W‧‧‧The overall width of the polarizer

α‧‧‧The angle formed by the extending direction E of the notch and the absorption axis A of the polarizer

Claims (27)

A polarizing plate is provided with a film-like polarizer. A concave notch is formed at the end of the polarizer. When the reference line L is defined as a straight line connecting one of the opposite corners of the two ends of the notch, the 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 entirety 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 claim 1, wherein the polarizer has a first end and a second end located on the opposite side of the first end, and the notch is formed at the first end, The notch extends from the first end to the second end, and the direction E in which the notch 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 and a second end located on the opposite side of the first end. A concave notch is formed at the first end. The notch extends from the first end toward the second end Extension, the direction E in which the notch extends is not parallel to the absorption axis A of the polarizer, Wc is the width of the notch in the direction parallel to the first end, and W is the width of the notch in the direction parallel to the first end. The width of the entire polarizer in the direction, Wc/W is 0.05 or more and less than 1.0. According to the polarizing plate described in any one of items 1 to 3 in the scope of the patent application, the protective film or the protective layer is closely adhered to both surfaces of the aforementioned polarizer. According to the polarizing plate described in any one of items 1 to 3 in the scope of patent application, in both surfaces of the aforementioned polarizer, the protective film or the protective layer is adhered to only one surface. The polarizing plate according to any one of items 1 to 3 in the scope of patent application, wherein a truncated portion is formed in the deep portion of the aforementioned notch. The polarizing plate described in the scope of patent application item 6, wherein the radius of curvature of the aforementioned truncated portion is 0.07 mm or more and 30 mm or less. According to the polarizing plate described in item 1 or 2 of the scope of patent application, 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 described in item 3 of the scope of patent application, wherein, when the reference line L is defined as a straight line connecting one of the opposite corners of the two ends of the notch, the reference line L and the absorption axis A of the polarizer Formed The angle θ is above 0° and less than 90°. The polarizing plate described in 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 75° or less. The polarizing plate described in item 3 of the scope of patent application, wherein, when the reference line L is defined as a straight line connecting one of the opposite corners of the two ends of the notch, 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 claim 1, wherein the polarizer has a first end and a second end located on the opposite side of the first end, and the notch is formed at the first end, The notch extends from the first end to the second end, and the angle α formed by the extending direction E of the notch and the absorption axis A of the polarizer is greater than 0° and less than 90°. The polarizing plate described in item 2 or 3 of the scope of patent application, wherein the angle α formed by the direction E in which the notch extends and the absorption axis A of the polarizer is greater than 0° and less than 90°. The polarizing plate described in 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 described in item 3 of the scope of patent application, wherein the aforementioned Wc/W is 0.10 or more and less than 1.0. The polarizing plate described in item 1 or 2 of the scope of patent application, wherein the width Wc of the notch in the direction parallel to the reference line L is 2 mm or more and less than 600 mm, and is in the direction parallel to the reference line L The width W of the entire polarizer is 30 mm or more and 600 mm or less, and the width Wc of the notch is less than the width W of the entire polarizer. The polarizing plate described in item 3 of the scope of patent application, wherein the width Wc of the notch in the direction parallel to the first end is 2 mm or more and less than 600 mm, and is in the direction parallel to the first end The width W of the entire polarizer is 30 mm or more and 600 mm or less, and the width Wc of the notch is less than the width W of the entire polarizer. The polarizing plate described in item 1 or 2 of the scope of patent application, wherein the length Dc of the notch in the direction perpendicular to the reference line L is 1 mm or more and 30 mm or less. The polarizing plate described in item 3 of the scope of patent application, wherein, when the reference line L is defined as a straight line connecting one of the opposite corners of the two ends of the notch, the notch in the 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 items 1 to 3 in the scope of patent application, wherein the thickness of the aforementioned polarizing plate is 1 μm or more and 10 μm or less. The polarizing plate according to claim 4, wherein, among the protective films or protective layers adhered to both surfaces of the polarizer, at least one of the protective films or protective layers contains cellulose triacetate. The polarizing plate according to claim 4, wherein at least one of the protective films or protective layers adhered to both surfaces of the polarizer contains a cyclic olefin polymer-based resin. The polarizing plate described in claim 4, wherein, among the protective films or protective layers adhered to both surfaces of the polarizer, at least one of the protective films or protective layers contains (meth)acrylic resin. An image display device comprising the polarizing plate as described in any one of items 1 to 23 in the scope of patent application. A method for manufacturing a polarizing plate includes the steps of producing a first laminated body including a polarizer film and at least one optical film superimposed on the polarizer film, and processing the first laminated body to produce a polarizer that is not compatible with the polarizer. The process of the second laminate at the first end where the absorption axis A of the sheet film is orthogonal, and the process of forming a concave notch at the first end; when the reference line L is defined as the connection between the notch at the In the case of a straight line at one of the opposite corners of the two ends, 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, Adjust Wc/W to 0.05 or more and less than 1.0. According to the method of manufacturing a polarizing plate described in claim 25, wherein the second laminate has a second end located on the opposite side of the first end, and the notch is removed from the first end Extend toward the second end, and adjust the extending direction E of the notch to a direction that is not parallel to the absorption axis A. A method of manufacturing a polarizing plate includes the steps of producing a first laminate including a polarizer film and at least one optical film superimposed on the polarizer film, and processing the first laminate to produce a first end portion The step of forming the second laminate at the second end opposite to the first end, and the step of forming a recessed notch on the first end; removing the notch from the first end Extend toward the second end, and adjust the extending direction E of the notch to a direction that is not parallel to the absorption axis A of the polarizer film, and Wc is parallel to the notch in the direction of the first end Width, W is the width of the entire polarizer in the direction parallel to the first end, and Wc/W is adjusted to be 0.05 or more and less than 1.0.

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