JP2018092119A - Polarization plate, image display device and polarization plate manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarization plate capable of curbing a crack due to a temperature change at a cutout section of a polarizer.SOLUTION: A polarization plate (1A) comprises a film polarizer (7). A concave cutout section (7C) is formed at a tip section (7e) of the polarizer (7). Given that a reference line L is defined as a straight line connecting a pair of corner sections (7C1 and 7C2) positioned at both edges of the cutout section (7C), the reference line L is not orthogonal to an absorption axis line A of the polarizer 7. Given that Wc represents a width of the cutout section (7C) in a direction parallel to the reference line L and W represents the width of the whole of the polarizer (7) in the direction parallel to the reference line L, Wc/W is 0.05 or more and less than 1.0.SELECTED DRAWING: Figure 3

Description

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

  The polarizing plate is one of optical components that constitute an image display device such as a liquid crystal television, an organic EL television, or a smartphone. The polarizing plate includes a film-like polarizer and an optical film (for example, a protective film) that overlaps the polarizer. For design reasons of the image display device, a cut-out portion may be formed at the end of the polarizer. For example, Patent Document 1 below describes forming a notch at the end of a polarizer as a liquid crystal injection port.

JP 2000-155325 A

  The polarizer expands or contracts as the temperature changes. As a result of studies by the present inventors, it has been found that cracks are formed in the notch due to the contraction of the polarizer accompanying the temperature change. In particular, cracks are likely to be formed due to thermal shock (rapid temperature change).

  The present invention has been made in view of the above circumstances, and a polarizing plate capable of suppressing cracks due to temperature changes in a notch portion of a polarizer, an image display device including the polarizing plate, and a polarizing plate It aims at providing the manufacturing method of.

  The polarizing plate according to one aspect of the present invention includes a film-like polarizer, the concave notch is formed at the end of the polarizer, and the reference line L is located at both ends of the notch. When defined as a straight line connecting a pair of corners, 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 width of the entire polarizer in the direction parallel to the reference line L, and 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 and a second end located on the opposite side of the first end, and the notch is in the first end. It may be formed, the notch may extend from the first end to the second end, and 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 between the direction E in which the notch extends and the absorption axis A of the polarizer may be greater than 0 ° and 90 ° or less.

  The method for producing a polarizing plate according to one aspect of the present invention includes a step of producing a first laminate including a polarizer film and at least one optical film overlapping the polarizer film, and processing the first laminate. A step of forming a second laminate 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 at the first end portion of the second laminate. , And the reference line L is defined as a straight line connecting a pair of corners located at both ends of the notch, Wc is the width of the notch in a 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, and adjusts Wc / W to 0.05 or more and less than 1.0.

  In the method for producing a polarizing plate according to one aspect of the present invention, the second laminate may have a second end located on the opposite side of the first end, and the notch from the first end. The direction E that extends toward the second end portion and the notch extends may be adjusted to a direction that is not parallel to the absorption axis A. In other words, the angle α between the direction E in which the notch extends and the absorption axis A of the polarizer film (polarizer) may 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-like polarizer, and the polarizer has a first end and a second end located on the opposite side of the first end, A concave notch is formed in the first end, the notch extends from the first end toward the second end, and the direction E in which the notch extends extends from the polarizer. Wc is the width of the notch in the direction parallel to the first end, W is the width of the entire polarizer in the direction parallel to the first end, and Wc is not parallel to the absorption axis A. / W is 0.05 or more and less than 1.0. In other words, in the polarizing plate according to another aspect of the present invention, the angle α formed by the extending direction E of the notch with the absorption axis A of the polarizer is greater than 0 ° and 90 ° or less.

  A method for producing a polarizing plate according to another aspect of the present invention includes a step of producing a first laminate including a polarizer film and at least one optical film overlapping the polarizer film, and processing the first laminate. And the process of producing the 2nd laminated body which has the 2nd end part located in the opposite side of the 1st end part and the 1st end part, and the process of forming the concave notch part in the 1st end part The notch is extended from the first end toward the second end, and the direction E in which the notch extends is adjusted to a direction not parallel to the absorption axis A, and Wc is the first The width of the notch in the direction parallel to the 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 extending direction E of the notch with the absorption axis A of the polarizer film (polarizer) is adjusted to be larger than 0 ° and not larger than 90 °.

  In any one of the above aspects of the present invention, a protective film or a protective layer may be adhered 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 in close contact with only one of the two surfaces of the polarizer. In any one of the above aspects of the present invention, the deep part of the notch may be chamfered.

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

  ADVANTAGE OF THE INVENTION According to this invention, the polarizing plate which can suppress the crack resulting from a temperature change in the notch part of a polarizer, the image display apparatus containing the said polarizing plate, and the manufacturing method of a polarizing plate are provided.

It is a typical perspective view of the polarizing plate which concerns on 1st embodiment of this invention. (A) in FIG. 2 is a top view of the polarizer included in the polarizing plate shown in FIG. 1, and (b) in FIG. 2 shows the polarizer shown in (a) in FIG. It is a modification. It is a top view of the polarizer with which the polarizing plate shown by FIG. 1 is provided, and is the enlarged view of (a) in FIG. It is a schematic diagram of the cross section of the image display apparatus (liquid crystal display device) which concerns on 1st embodiment of this invention. It is a typical perspective view of the polarizing plate which concerns on 2nd embodiment of this invention. It is a schematic diagram of the cross section of the image display apparatus (liquid crystal display device) which concerns on 2nd embodiment of this invention. (A) in FIG. 7 is a top view of a polarizer provided in a polarizing plate according to another embodiment of the present invention, and (b) in FIG. 7 is a polarizing plate according to another embodiment of the present invention. FIG. 7C is a top view of the polarizer included in the polarizing plate according to another embodiment of the present invention. (A) in FIG. 8 is a top view of a polarizer provided in a polarizing plate according to another embodiment of the present invention, and (b) in FIG. 8 is a polarizing plate according to another embodiment of the present invention. FIG. 8C is a top view of the polarizer included in the polarizing plate according to the example of the present invention. It is a top view of the polarizer with which the polarizing plate concerning other embodiments of the present invention is provided. It is a top view of the polarizer with which the polarizing plate concerning other embodiments of the present invention is provided. It is a typical perspective view of the polarizing plate which concerns on the comparative example of this invention. It is a top view of the polarizer with which the polarizing plate shown by FIG. 11 is provided. It is a top view of the polarizer with which the polarizing plate concerning some examples of the present invention is provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals. The present invention is not limited to the following embodiment. X, Y, and Z shown in each figure mean three coordinate axes orthogonal to each other. The direction indicated by each coordinate axis is common to all drawings.

(First embodiment)
1st Embodiment is described based on Fig.1, Fig.2 (a), Fig.2 (b), and Fig.3. The polarizing plate 1 </ b> A according to the first embodiment includes a film-like polarizer 7 and a plurality of optical films (3, 5, 9, 13) that overlap the polarizer 7. Both the polarizer 7 and the plurality of optical films (3, 5, 9, 13) are quadrangular. The “optical film” means a film-like member (excluding the polarizer itself) constituting the polarizing plate. The optical film may be rephrased as a layer or an optical layer. The optical film implies, 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 (separator). . That is, the polarizing plate 1 </ b> A includes the polarizer 7, the first protective film 5, the second protective film 9, the third protective film 3, and the release film 13. The polarizing plate 1 </ b> A also includes an adhesive layer 11 positioned between the second protective film 9 and the release film 13. The first protective film 5 overlaps one surface of the polarizer 7, and the second protective film 9 overlaps the other surface of the polarizer 7. That is, the protective film (protective layer) is in close contact with 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 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 cut-out portion (C) 7C (concave cut-out portion) is formed at the end portion (first end portion 7e) of the polarizer 7. This notch 7C is formed in 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. In other words, a concave notch common to all of the polarizer 7, the optical films (3, 5, 9, 13) and the adhesive layer 11 constituting the polarizing plate 1 </ b> A is formed on the end face of the polarizing plate 1 </ b> A. . The shape of the notch 7C of the polarizer 7 viewed from the stacking direction (Z-axis direction) may be the same as or similar to the shape of the notch of the polarizing plate 1A viewed from the stacking direction. The shape of the notch of the polarizing plate 1A viewed from the stacking direction may be regarded as the shape of the notch 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 be referred to as “notch portion 7C”. The notch 7C is, for example, a rectangle.

  The reference line L is defined as a straight line connecting a pair of corner portions 7C1 and 7C2 located at both ends of the notch portion 7C. The reference line L may be rephrased as a straight line connecting the pair of corner portions 7C1 and 7C2 in the direction perpendicular to the 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 absorption axis A may be rephrased as, for example, a straight line substantially parallel to the orientation direction of polyvinyl alcohol (PVA) molecules in the polarizer 7. The absorption axis A may be rephrased as, for example, a straight line substantially parallel to the orientation direction of a dye molecule (for example, polyiodine or organic dye) adsorbed on polyvinyl alcohol in the polarizer 7. It can be said that many carbon atoms constituting one PVA molecule are bonded to each other by a covalent bond (CC bond) along the absorption axis A. On the other hand, in the direction substantially perpendicular to the absorption axis A, the PVA molecules are bonded by a cross-linking bond via a cross-linking agent (for example, boric acid). In other words, in the direction substantially perpendicular to the absorption axis A, the hydroxy group of each PVA molecule forms a hydrogen bond or an oxygen-boron bond (OB bond) with boric acid located between the PVA molecules. The PVA molecules are cross-linked with each other. The CC 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 the direction substantially parallel to the absorption axis A is higher than the mechanical strength of the polarizer 7 in the direction substantially perpendicular to the absorption axis A. In other words, the thermal contraction of the polarizer 7 in the direction substantially parallel to the absorption axis A is less likely to cause cracks than the thermal contraction of the polarizer 7 in the direction substantially perpendicular to the absorption axis A.

  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, the PVA molecule A weak cross-linked bond is formed as compared with the CC bond in the inside. Therefore, when the reference line L is orthogonal to the absorption axis A, when the deep part (back part) of the notch 7C contracts in a direction substantially parallel to the reference line L, a crack 7cr is formed in the deep part of the notch 7C. easy.

  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 between the reference line L and the absorption axis A is 0 ° or more and less than 90 °. Therefore, the CC bond in the PVA molecule which is stronger than the cross-linking bond between the PVA molecules increases the mechanical strength of the polarizer 7 in the direction parallel to the reference line L. As a result, even if the deep portion of the cutout portion 7C contracts in a direction substantially parallel to the reference line L, the crack 7cr is hardly formed in the deep portion of the cutout portion 7C. In particular, when the reference line L is parallel to the absorption axis A (when the angle θ is 0 °), CC bonds in most PVA molecules constituting the polarizer 7 are formed along the absorption axis A. Has been. 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 remarkably high, and the formation of the crack 7cr in the notch 7C is remarkably suppressed. .

  As the angle θ formed by the reference line L and the absorption axis A is smaller, the crack 7cr is less likely to be formed in the notch 7C. The angle θ may be from 0 ° to 75 °, or from 0 ° to 60 °.

  The polarizer 7 has a first end 7e in which a notch 7C is formed, and a second end 17e located on the opposite side of the first end 7e. In the first embodiment, both of the first end 7e and the second end 17e are linear, and the first end 7e is parallel to the second end 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 is not 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 90 ° or less. 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 longitudinal 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.

  Since the direction E in which the notch 7C extends is not parallel to the absorption axis A of the polarizer 7, the CC bond in the PVA molecule is stronger than the cross-linking bond between the PVA molecules in the direction perpendicular to the direction E. The mechanical strength of the polarizer 7 is increased. As a result, even if the deep portion of the cutout portion 7C contracts in a direction substantially perpendicular to the direction E, the crack 7cr is hardly formed in the deep portion of the cutout portion 7C. As the angle α formed by the direction E with the absorption axis A is larger, the crack 7cr is less likely to be formed in the notch 7C. In particular, when the direction E is perpendicular to the absorption axis A (when the angle α is 90 °), CC bonds in most PVA molecules constituting the polarizer 7 are formed perpendicular to the direction E. Has been. 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 high, and the formation of the crack 7cr in the notch 7C is remarkably suppressed.

  The width Wc of the notch 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 be rephrased as the width of the cutout portion 7C in the direction parallel to the end portion (first end portion 7e) of the polarizer 7. The width W of the entire polarizer 7 in the direction parallel to the reference line L may be, for example, 30 mm or more and 600 mm or less. The width W of the entire polarizer 7 may be rephrased as the width of the entire polarizing plate 1A in the direction parallel to the reference line L. The width W may be paraphrased as the width of the entire polarizer 7 in the direction parallel to the first end portion 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 width W of the entire polarizer 7 (width of the entire polarizing plate 1A) is greater than 20 mm and 160 mm or less, preferably greater than 25 mm and 130 mm or less, more preferably It may be greater than 30 mm and not greater than 100 mm, more preferably greater than 30 mm and not greater than 70 mm (Wc <W). The ratio Wc / W between the width Wc of the notch 7C and 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. Less than 1.0, more preferably 0.20 or more and less than 1.0, or 0.22 or more and less than 1.0, still more preferably 0.30 or more and less than 1.0, 0.33 or more and less than 1.0, or 0 It may be 40 or more and less than 1.0. The ratio Wc / W may be 0.05 to 0.90, 0.05 to 0.80, 0.05 to 0.78, or 0.05 to 0.45. The ratio Wc / W may be rephrased as a ratio of the width Wc of the notch 7C and the width W of the entire polarizing plate 1A. When the ratio Wc / W is in the above range, cracks at the notch 7C are easily suppressed. The reason is as follows. As the width Wc of the notch portion 7C is smaller than the entire width W of the polarizer 7, a force for expanding the width Wc of the notch portion 7C is more likely to occur due to contraction of the entire polarizer 7 due to temperature change. Cracks are likely to occur in 7C. In other words, the smaller Wc / W, the easier it is for cracks to occur in the cutout portion 7C. On the other hand, as Wc / W is larger (the width W of the entire polarizer 7 is smaller), the contraction amount of the entire polarizer 7 due to the temperature change is reduced. That is, the absolute value of the amount of change in the overall width W of the polarizer 7 is reduced as the overall width W of the polarizer 7 is smaller. Due to the reduction in the amount of shrinkage of the entire polarizer 7 due to the temperature change, it is difficult to generate a force for expanding the width Wc of the notch 7C, and cracks in the notch 7C are easily suppressed.

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

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 long strip-shaped polarizer film is the polarizer 7 before processing and molding. The absorption axis of the polarizer film may be the same as the absorption axis A of the polarizer 7 after processing and molding. The long strip-shaped optical films are optical films (3, 5, 9, 13) before processing and molding. In the subsequent processing step, the first laminate is processed to produce a plurality of laminates (second laminates) having desired dimensions and shapes. Like the polarizing plate 1A, the second laminated body has a first end 7e that is not orthogonal to the absorption axis A of the polarizer film (polarizer 7) and a first end 7e that is located on the opposite side of the first end 7e. And two end portions 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 portion that is not orthogonal to the absorption axis A. In the processing step, for example, the second laminate may be produced by cutting the first laminate with a blade. In the processing step, for example, the second laminate may be produced by punching the first laminate. In the processing step, for example, the second laminate may be produced by cutting the first laminate with a laser. The laser may be, for example, a CO ₂ laser or an excimer laser. In the processing step, for example, the second laminate may be manufactured by combining cutting using the above-described blade, punching, and cutting using a laser. The first laminated body is processed by the above-described processing method, and after adjusting the dimension of the first laminated body to be larger than a predetermined dimension, the end of the first laminated body is cut and polished with a milling cutter. May be produced.

  In the processing step, the concave notch portion 7C may be formed in the first end portion 7e of the second laminate by, for example, punching processing or cutting using a blade or a laser. When forming the cutout portion 7C in the processing step, the cutout portion 7C extends from the first end portion 7e toward the second end portion 17e, and the direction E in which the cutout portion 7C extends is not parallel to the absorption axis A Adjust the direction. After producing the 2nd laminated body in which the notch part 7C was formed in the process step, you may perform an edge part process step. In the end portion processing step, for example, the end surface of the second laminated body including the notch portion 7C may be cut and polished using an end mill. An end mill is a kind of milling cutter. The end mill cuts and polishes the end surface of the second laminate including the notch portion 7C, for example, with a blade 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 is finished smoothly. By using this end mill, the second laminate can be formed into a polarizing plate 1A having a desired shape and dimensions in a short time. That is, the productivity of the polarizing plate 1A is improved. In the processing step, the first laminate may be punched larger than before to produce a second laminate, and in the subsequent end portion processing step, the end face of the second laminate may be cut and polished with an end mill. As a result, the margin of the edge part removed from the second laminate in the end part processing step is reduced, and the generation of foreign matters such as polishing debris in the end part processing step is suppressed. ) Is suppressed.

  The notch portion 7C may not be formed in the processing step, and the concave notch portion 7C may be formed in the first end portion 7e of the second stacked body in the end portion processing step subsequent to the processing step. Also in the case of forming the notch 7C in the end machining step, the notch 7C is extended from the first end 7e toward the second end 17e, and a direction E in which the notch 7C extends is defined as an absorption axis A. Adjust in a direction that is not parallel to In the end portion processing step, for example, the notched portion 7C may be formed in the second stacked body by irradiating the end portion of the second stacked body with the laser and cutting a part or all of the end portion. . The notch 7C may be formed in the second laminate by the end machining step using the above-described end mill. In either the above machining step or the end machining step, 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 is already known at the time of the processing step and the end processing step. Therefore, for example, as described above, by adjusting the direction of punching or cutting of the first laminate, the angle formed by the first end 7e of the second laminate with the absorption axis A is adjusted to 0 ° or more and less than 90 °. By doing so, the angle θ between 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, when forming the notch portion 7C in the first end portion 7e of the second stacked body, the angle α between the direction E and the absorption axis A is adjusted by adjusting the orientation of the notch portion 7C. , And can be freely controlled within a range of 0 ° to 90 °. As described above, the relative positional relationship between the reference line L and the absorption axis A is controlled by the punching or cutting direction of the first stacked body and the position where the cutout portion 7C is formed in the second stacked body. The relative positional relationship between the direction E and the absorption axis A is controlled by the position where the cutout portion 7C is formed and the orientation of the cutout portion 7C in the second laminate. The direction of the absorption axis A itself in the polarizer film (polarizer 7) is adjusted and controlled by the stretching direction and stretching ratio of the PVA film performed before the processing step and the edge processing step.

  The polarizer 7 may be a film-like polyvinyl alcohol resin (PVA film) produced by processes such as stretching, dyeing, and crosslinking. Details of the polarizer 7 are as follows.

  For example, first, a PVA film is stretched in a uniaxial direction or a biaxial direction. The dichroic ratio of the polarizer 7 stretched in the uniaxial direction tends to be high. Following stretching, the PVA film is dyed with iodine, a dichroic dye (polyiodine) or an organic dye using a dyeing solution. The staining liquid may contain boric acid, zinc sulfate, or zinc chloride. The PVA film may be washed with water before dyeing. By washing with water, dirt and an antiblocking agent are removed from the surface of the PVA film. In addition, as a result of swelling of the PVA film by washing with water, staining spots (non-uniform staining) are easily suppressed. The dyed PVA film is treated with a solution of a crosslinking agent (for example, an aqueous solution of boric acid) for crosslinking. After the treatment with the crosslinking agent, the PVA film is washed with water and subsequently dried. Through the above procedure, the polarizer 7 is obtained. The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate resin. The polyvinyl acetate resin is, for example, polyvinyl acetate, which is a homopolymer of vinyl acetate, or a copolymer of vinyl acetate and another monomer (for example, ethylene-vinyl acetate copolymer). Good. Other monomers that copolymerize 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-based resin may be modified with aldehydes. The modified polyvinyl alcohol resin may be, for example, partially formalized polyvinyl alcohol, polyvinyl acetal, or polyvinyl butyral. The polyvinyl alcohol resin may be a polyene oriented film such as a dehydrated polyvinyl alcohol product or a dehydrochlorinated polyvinyl chloride product. Dyeing may be performed before stretching, or stretching may be performed in a dyeing solution. The length of the stretched polarizer 7 may be, for example, 3 to 7 times the length before stretching.

  The thickness of the polarizer 7 may be, for example, 1 μm to 50 μm, 1 μm to 10 μm, 1 μm to 8 μm, 1 μm to 7 μm, or 4 μm to 30 μm. As the polarizer 7 is thinner, the contraction of the polarizer 7 itself due to the temperature change is suppressed, and the change in the dimension of the polarizer 7 itself is suppressed. As a result, stress hardly acts on the polarizer 7 and cracks in the polarizer 7 are easily suppressed.

  The 1st protective film 5 and the 2nd protective film 9 should just be a thermoplastic resin which has translucency, and may be an optically transparent thermoplastic resin. Resins constituting the first protective film 5 and the second protective film 9 are, for example, a chain polyolefin resin, a cyclic olefin polymer resin (COP resin), a cellulose ester resin, a polyester resin, a polycarbonate resin, ( It may be a (meth) acrylic resin, a polystyrene resin, or a mixture or copolymer thereof. The composition of the first protective film 5 may be exactly the same as the composition of the second protective film 9. The composition of the first protective film 5 may be different from the composition of the second protective film 9.

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

  The cyclic olefin polymer resin (cyclic polyolefin resin) may be, for example, a cyclic olefin ring-opening (co) polymer or a cyclic olefin addition polymer. The cyclic olefin polymer-based 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-based resin may be a graft polymer obtained by modifying the above polymer with an unsaturated carboxylic acid or a derivative thereof, or a hydride thereof. The cyclic olefin polymer resin may be, for example, a norbornene resin using a norbornene monomer such as norbornene or a polycyclic norbornene monomer.

  The cellulose ester resin may be, for example, cellulose triacetate (triacetyl cellulose (TAC)), cellulose diacetate, cellulose tripropionate, or cellulose dipropionate. These copolymers may be used. A cellulose ester resin in which a part of the hydroxyl group is modified with another substituent may be used.

  Polyester resins other than cellulose ester resins may be used. The polyester resin may be, for example, a polycondensate of a polyvalent carboxylic acid or derivative thereof and a polyhydric alcohol. The polyvalent carboxylic acid or derivative thereof may be a dicarboxylic acid or derivative thereof. The polyvalent carboxylic acid or derivative thereof may be, for example, terephthalic acid, isophthalic acid, dimethyl terephthalate, or dimethyl naphthalenedicarboxylate. The polyhydric alcohol may be, for example, a diol. The polyhydric alcohol may be, for example, ethylene glycol, propanediol, butanediol, neopentyl glycol, or cyclohexanedimethanol.

  The polyester resin may be, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, or polycyclohexanedimethyl naphthalate. .

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

  (Meth) acrylic resin is, for example, poly (meth) acrylic acid ester (for example, polymethyl methacrylate (PMMA)); methyl methacrylate- (meth) acrylic acid copolymer; methyl methacrylate- (meth) acrylic Acid ester copolymer; methyl methacrylate-acrylic ester- (meth) acrylic acid copolymer; (meth) methyl acrylate-styrene copolymer (for example, MS resin); methyl methacrylate and alicyclic hydrocarbon It may be a copolymer with a compound having a group (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-norbornyl copolymer (meth) acrylate).

  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 triacetyl cellulose (TAC). 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 include a cyclic olefin polymer resin (COP resin). At least one of the pair of optical films (first protective film 5 and second protective film 9) sandwiching the polarizer 7 may include polymethyl methacrylate (PMMA). Both of the pair of optical films (first protective film 5 and second protective film 9) sandwiching the polarizer 7 may include triacetyl cellulose. One film of the pair of optical films (first protective film 5 and second protective film 9) sandwiching the polarizer 7 contains triacetyl cellulose, and the other film of the pair of optical films sandwiching the polarizer 7 is A cyclic olefin polymer may be included. One film of the pair of optical films (first protective film 5 and second protective film 9) sandwiching the polarizer 7 contains triacetyl cellulose, and the other film of the pair of optical films sandwiching the polarizer 7 is Polymethyl methacrylate may also be included. One film of the pair of optical films (first protective film 5 and second protective film 9) sandwiching the polarizer 7 includes a cyclic olefin polymer resin, and the other of the pair of optical films sandwiching the polarizer 7 The film may comprise 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 in close contact with the polarizer 7 and the polarizer 7 accompanying a temperature change. Therefore, cracks in the polarizer 7 are unlikely to occur. 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 difficult to occur.

  The first protective film 5 or the second protective film 9 is 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. Additives may be included.

  The thickness of the first protective film 5 may be, for example, 5 μm to 90 μm, 5 μm to 80 μm, or 5 μm to 50 μm. The thickness of the second protective film 9 may also be, for example, 5 μm to 90 μm, 5 μm to 80 μm, or 5 μm to 50 μm.

  The first protective film 5 or the second protective film 9 may be a film having an optical function, such as a retardation film or a brightness enhancement film. For example, a retardation film to which an arbitrary retardation value is given can be obtained by stretching a film made of the thermoplastic resin or forming a liquid crystal layer or the like on the film.

  The first protective film 5 may be bonded to the polarizer 7 through an adhesive layer. The second protective film 9 may also be bonded to the polarizer 7 via an adhesive layer. The adhesive layer may contain an aqueous adhesive such as polyvinyl alcohol, and may contain an active energy ray-curable resin described later.

  The active energy ray-curable resin is a resin that cures when irradiated with active energy rays. The active energy ray may be, for example, ultraviolet light, visible light, electron beam, or X-ray. The active energy ray curable resin may be an ultraviolet curable resin.

  The active energy ray-curable resin may be a kind of resin and may include a plurality of kinds of resins. For example, the active energy ray curable resin may contain a cationic 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 for initiating a curing reaction of the 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 oxetane compound (a compound having at least one oxetane ring in the molecule). The radical polymerizable curable compound may be, for example, a (meth) acrylic compound (a compound having at least one (meth) acryloyloxy group in the molecule). The radical polymerizable curable compound may be a vinyl compound having a radical polymerizable double bond.

  The active energy ray curable resin may be a cationic polymerization accelerator, an ion trapping agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, or an antifoaming agent, if necessary. Agents, antistatic agents, leveling agents, or solvents.

  The pressure-sensitive adhesive layer 11 may include, for example, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or a urethane-based pressure-sensitive adhesive. The thickness of the adhesion layer 11 may be 2 μm or more and 500 μm or less, 2 μm or more and 200 μm or less, or 2 μm or more and 50 μm or less, for example.

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

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

  The image display device according to 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 30 </ b> A according to the first embodiment includes a liquid crystal cell 10 and a polarizing plate 1 </ b> Aa (first polarizing plate) that overlaps one surface (first surface) of the liquid crystal cell 10. And another polarizing plate 1Ab (second polarizing plate) that overlaps the other surface (second surface) of the liquid crystal cell 10. The second surface may be rephrased as the back surface of the first surface. The polarizing plates 1Aa and 1Ab shown in FIG. 4 are the same as the polarizing plate 1A shown in FIG. 1 except that the release film 13 and the third protective film 3 are not provided. The polarizing plate 1 </ b> Aa (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) includes an adhesive layer 11 that overlaps the first surface of the liquid crystal cell 10, a second protective film 9 that overlaps the adhesive layer 11, a polarizer 7 that overlaps the second protective film 9, and polarized light. And a first protective film 5 overlapping the child 7. Another polarizing plate 1 </ b> Ab (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) includes an adhesive layer 11 that overlaps the second surface of the liquid crystal cell 10, a second protective film 9 that overlaps the adhesive layer 11, and a polarizer 7 that overlaps the second protective film 9. And the first protective film 5 overlapping 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 the backlight (surface light source device) and other members constitute the liquid crystal display device 30A. The backlight and other members are omitted in FIG.

(Second embodiment)
Below, 2nd embodiment of this invention shown by FIG.5 and FIG.6 is described. Also in the second embodiment, cracks due to temperature changes can be suppressed in the notch portion of the polarizer by the same mechanism as in the first embodiment. Hereinafter, matters unique to the second embodiment (differences between the first embodiment and the second embodiment) will be described. In matters not explained below, the second embodiment is common to the first embodiment.

  A polarizing plate 1B according to 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. In the second embodiment, the first protective film 5 is in close contact with one surface of both surfaces of the polarizer 7, and the third protective film 3 overlaps the first protective film 5. Not the second protective film 9 but the adhesive layer 11 is in direct contact with the other surface of the polarizer 7. That is, the adhesive layer 11 is sandwiched between the polarizer 7 and the release film 13. As described above, the polarizing plate 1B according to the second embodiment is different from the polarizing plate 1A according to the first embodiment in that the second protective film 9 is not provided. In other words, only one surface of the polarizer 7 included in the polarizing plate 1B according to the second embodiment is protected by the first protective film 5 (protective layer), and the other surface of the polarizer 7 is protected by the protective film (protective layer). It has not been. Generally, compared to a polarizer whose both surfaces are protected by a protective form (protective layer), a polarizer whose only one surface is protected by a protective film (protective layer) has cracks caused by temperature changes. It is easy to form in the notch. 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 is suppressed. In the second embodiment, as in the first embodiment, since the extending direction E of the cutout portion 7C is not parallel to the absorption axis A, the formation of the crack 7cr in the cutout portion 7C is easily suppressed.

  As shown in FIG. 6, the liquid crystal display device 30 </ b> B according to the second embodiment includes a liquid crystal cell 10, a polarizing plate 1 </ b> Ba (first polarizing plate) that overlaps one surface (first surface) of the liquid crystal cell 10, and a liquid crystal Another polarizing plate 1Bb (second polarizing plate) overlapping the other surface (second surface) of the cell 10. The polarizing plates 1Ba and 1Bb shown in FIG. 6 are the same as the polarizing plate 1B shown in FIG. 5 except that the release film 13 and the third protective film 3 are not provided. 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) includes an adhesive layer 11 that overlaps the first surface of the liquid crystal cell 10, a polarizer 7 that overlaps the adhesive layer 11, and a first protective film 5 that overlaps the polarizer 7. Another polarizing plate 1 </ b> Bb (second polarizing plate) is attached to the second surface of the liquid crystal cell 10 via the adhesive layer 11. Another polarizing plate 1Bb (second polarizing plate) includes an adhesive layer 11 that overlaps the second surface of the liquid crystal cell 10, a polarizer 7 that overlaps the adhesive layer 11, and a first protective film 5 that overlaps the polarizer 7. Have. 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 the backlight (surface light source device) and other members constitute the liquid crystal display device 30B. The backlight and other members are omitted in FIG.

(Other embodiments)
As mentioned above, although 1st embodiment and 2nd embodiment of this invention were described, this invention is not limited to the said embodiment.

  For example, as long as the reference line L that connects a pair of corners located at both ends of each notch is not perpendicular to the absorption axis A of the polarizer, a plurality of notches may be formed in the polarizing plate.

  The shape of each of the polarizing plate and the notch may be various shapes depending on the application. For example, as shown in FIG. 7A, the width of the notch 7C in the direction parallel to the reference line L may be larger 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 cutout portion 7C may be a semicircle. As shown in (c) of FIG. 7, the shape of the cutout portion 7C may be a triangle. The shape of the cutout portion 7C may be a polygon other than a quadrangle and a triangle. The shape of each of the polarizers 7 shown in (a) in FIG. 7, (b) in FIG. 7 and (c) in FIG. 7 is regarded as the shape of a polarizing plate provided with each polarizer 7. It's okay. In other words, the shape of the notch 7C formed in each polarizer 7 shown in (a) in FIG. 7, (b) in FIG. 7 and (c) in FIG. 7 may be regarded as the shape of the notch formed in the polarizing plate having 7.

  As shown to (a) in FIG. 8, the outer edge (the 1st end part 7e and the 2nd end part 17e) of the polarizer 7 may be circular. As shown in FIG. 8B, a chamfered part 7C3 and a chamfered part 7C4 may be formed in the deep part (corner part) of the notch part 7C. The corners 7C1 and 7C2 located at both ends of the notch 7C may also be chamfered. When the corner 7C1 and the corner 7C2 located at both ends of the notch 7C are chamfered, the reference line L may be rephrased as a straight line in contact with the corner 7C1 and the corner 7C2. The outer corner CR1, the outer corner CR2, the outer corner CR3, and the outer corner CR4 located at the outer edge of the polarizer 7 may also be chamfered. The chamfering can be performed, for example, by cutting and polishing the notch and the outer edge used in the end mill. The shape of each of the polarizers 7 shown in (a) in FIG. 8, (b) in FIG. 8, and (c) in FIG. 8 is regarded as the shape of a polarizing plate provided with each polarizer 7. It's okay. In other words, the shape of the notch 7C formed in each polarizer 7 shown in (a) in FIG. 8, (b) in FIG. 8, and (c) in FIG. 7 may be regarded as the shape of the notch formed in the polarizing plate having 7. As illustrated in FIG. 13, a chamfered portion 7 </ b> C <b> 3 may be formed in the deep portion (the deepest portion) of the triangular cutout portion 7 </ b> C. The shape of the notch 7 </ b> C formed in the polarizer 7 shown in FIG. 13 may be regarded as the shape of the notch formed in the polarizing plate including the polarizer 7. As shown in FIG. 8B and FIG. 13, since the deep portion of the cutout portion 7C is chamfered, cracks in the cutout portion 7C are easily suppressed. The chamfered portion 7C3 and the chamfered portion 7C4 shown in (b) of FIG. 8 may be rephrased as a curved deep portion (corner portion) of the notch portion. The chamfered portion 7C3 shown in FIG. 13 may also be referred to as a curved deep portion (corner portion) of the notch portion. As the curvature radius of the curved deep portion (corner portion) of the cutout portion 7C is larger, cracks in the cutout portion 7C are more easily suppressed. For example, when the curvature radius of the curved deep portion (corner portion) of the cutout portion 7C is 0.07 mm or more, cracks in the cutout portion 7C are easily suppressed. The curvature radius of the curved deep part (corner part) of the notch C is, for example, 0.07 mm to 30 mm, or 0.07 mm to 10 mm, preferably 0.09 mm to 30 mm, or 0.09 mm to 10 mm. The following is sufficient.

  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 of the polarizer may be linear, and the remaining part of the first end of the polarizer may be curved. The first end of the polarizer may consist of only one or more straight lines (one or more sides). The 1st end part of a polarizing plate may consist only of a curve. A part of the second end of the polarizer may be linear, and the remaining part of the second end of the polarizer may be curved. The second end of the polarizer may consist of only one or more straight lines (one or more sides). The 2nd end part of a polarizing plate may consist only of a curve. Each shape of the polarizer and the polarizing plate may be a polygon other than a quadrangle. The respective shapes of the polarizer and the polarizing plate may be elliptical, for example. The 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 7e where the notch 7C is formed may not be parallel to the second end 17e. As shown in FIG. 9, when the first end 7e is not parallel to the second end 17e and the deep part 7Cd (bottom part) of the notch 7C is linear, “the direction in which the notch 7C extends” is shown. “E” may be defined as a direction parallel to a straight line that bisects the line segment S connecting the pair of corners 7C1 and 7C2 and bisects the linear deep part 7Cd of the notch 7C. When the pair of corner portions 7C1 and 7C2 are chamfered, the line segment S may be a line segment that contacts both 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 of the notch portion 7C extends" , A direction parallel to a straight line connecting the deep part 7Cd (deepest part) of the notch part 7C and the midpoint Sc of the line segment S may be defined. If the deep portion 7Cd of the curved cutout portion 7C is branched into a plurality of branches, the “extending direction E of the cutout portion 7C” corresponds to the plurality of deep portions (deepest portions) of the cutout portion 7C and line segments. It may be defined as a direction parallel to a straight line connecting the midpoint Sc of S. Since the direction E corresponding to each of the plurality of deep portions (the deepest portion) of the notch portion 7C is not parallel to the absorption axis A, cracks in each deep portion are suppressed.

  The kind of optical film which comprises a polarizing plate, the number, and the order of lamination | stacking are not limited. For example, the modification of the polarizing plate according to 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. That is, not the first protective film 5 but the third protective film 3 may be in close contact with one surface of both surfaces of the polarizer 7. The second protective film 9 may be in close contact with the other surface of the polarizer 7, and the release film 13 may overlap the second protective film 9 via the adhesive layer 11. As described above, the modification of the polarizing plate according to the second embodiment may be different from the polarizing plate 1B according to the second embodiment in that the first protective film 5 is not provided and the second protective film 9 is provided. .

  The number of optical films provided in the polarizing plate may be one. For example, the modified example of the polarizing plate 1 </ b> A illustrated in FIG. 1 may not include both the first protective film 5 and the second protective film 9. For example, one or both of the polarizing plate 1Aa (first polarizing plate) and the polarizing plate 1b (second polarizing plate) shown in FIG. 4 includes the first protective film 5 and / or the second protective film 9. It does not have to be.

  The polarizing plate 1 </ b> A may not include one or both of the third protective film 3 and the release film 13. For example, the third protective film 3 may be peeled off 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 also be peeled off from the polarizing plate 1A during the manufacturing process of the image display device.

  Instead of the first protective film 5 or the second protective film 9, a thinner protective layer may be directly stacked on the polarizer. 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 irradiation with active energy rays, a protective layer thinner than a conventional protective film is directly formed on the surface of the polarizer. Is done. In other words, a thin protective layer may be formed from the active energy ray curable resin itself used for bonding the polarizer and the protective film.

  The release film may be arrange | positioned on both surfaces of the polarizing plate through the adhesion layer.

  The optical film included in the polarizing plate is a reflective polarizing film, a film with an antiglare function, a film with a surface antireflection function, a reflective film, a transflective film, a viewing angle compensation film, an optical compensation layer, a touch sensor layer, an antistatic layer. Or an antifouling layer may be sufficient.

  The polarizing plate may further include a hard coat layer. For example, in the modification of the polarizing plate 1A shown in FIG. 1, the first protective film 5 may be positioned between the hard coat layer and the polarizer 7, and the hard coat layer is formed between the first protective film 5 and the first protective film 5. It may be located between the three protective films 3. In this case, the first protective film 5 may contain triacetyl cellulose.

  A hard-coat layer is a layer comprised from the acrylic resin film in which the fine uneven | corrugated shape was provided in the surface, for example. The hard coat layer may be formed from a coating film containing organic fine particles or inorganic fine particles, for example. You may use the method (for example, embossing method etc.) which presses this coating film on the roll which has uneven | corrugated shape. After forming a coating film that does not contain organic fine particles or inorganic fine particles, a method of pressing the coated film against a roll having an uneven shape may be used. The inorganic fine particles may 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 acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, polyimide particles, and the like. . The binder component for dispersing the inorganic fine particles or the organic fine particles may be selected from materials having high hardness (hard coat). 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, an ultraviolet curable resin is preferably used as the binder component. The thickness of the hard coat layer may be, for example, 2 μm to 30 μm, or 3 μm to 30 μm.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples.

Example 1
A rectangular first laminate 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 that overlaps the release film 13, a second protective film 9 that overlaps the adhesive layer 11, a polarizer film (7) that overlaps the second protective film 9, and The first protective film 5 overlapping the polarizer film (7) and the third protective film 3 overlapping the first protective film 5 were provided. As the polarizer film (7), stretched and dyed film-like polyvinyl alcohol was used. As the first protective film 5, a triacetyl cellulose (TAC) film was used. As the second protective film 9, a film composed of a cyclic olefin polymer resin (COP resin) was used. As the third protective film 3, a PET protective film was used. As the release film 13, a PET separator was used. The release film 13 had a thickness of 38 μm. The thickness of the adhesive layer 11 was 20 μm. The thickness of the second protective film 9 was 13 μm. The thickness of the polarizer 7 was 7 μm. The thickness of the first protective film 5 was 25 μm. The thickness of the third protective film 3 was 58 μm.

  Said 1st laminated body was cut | disconnected with the cutter, and the length of a horizontal side was 170 mm, and the 2nd laminated body whose length of a vertical side is 100 mm was produced. When cutting the first laminated body, by adjusting the cutting direction of the first laminated body, the angle θ between the lateral side (first end) of the second laminated body and the absorption axis A of the polarizer 7 is set. Were adjusted to the angles shown in Table 1 below. The absorption axis A of the polarizer 7 was parallel to the stretching direction of the polarizer film (7).

The second laminate was adsorbed on the stage and fixed. By irradiating the outer edge of the fixed second laminate with a CO ₂ laser, a concave notch was formed on the lateral side (first end) of the second laminate. The polarizing plate of Example 1 was obtained through the above process. The output of the CO ₂ laser was set to 20W. The oscillation wavelength of the CO ₂ laser was 10.4 μm.

  The shape of the obtained polarizing plate was the same as the shape of the polarizer 7 shown in (c) of FIG. That is, the polarizer 7 shown in FIG. 8C is a polarizer included in the polarizing plate manufactured by the above procedure. The shape of the cutout portion 7C formed in the first end portion 7e of the polarizer 7 (the lateral side of the second laminate) was almost a semicircle. When the reference line L is defined as a straight line connecting the corners 7C1 and 7C2 located at both ends of the notch 7C, the angle formed by the reference line L and the absorption axis A is equal to the angle θ described above. 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 portion 7C1 and the corner portion 7C2 was 20 mm. The depth of the notch 7C in the direction perpendicular to the reference line L was 10 mm. The width W of the first end portion 7e of the polarizer 7 formed with the notch portion 7C was 150 mm. That is, the length of the lateral side of the polarizing plate (lateral width W of the polarizing plate) was 150 mm. The length of the vertical side of the polarizing plate (vertical width of the polarizing plate) was 80 mm. Wc / W was 20 mm / 150 mm, that is, 0.13.

The release film 13 was peeled off from the adhesive layer 11 of the polarizing plate, and the polarizing plate was bonded to the glass plate via the adhesive layer 11. Furthermore, the 3rd protective film 3 was peeled from the polarizing plate. By such a procedure, a sample comprising a glass plate and a polarizing plate bonded to the glass plate was prepared. A heat cycle test was conducted using this sample. In the heat cycle test, a cycle consisting of the following step 1 and step 2 following step 1 was repeated.
Step 1: heating the sample in an atmosphere at 85 ° C. for 30 minutes.
Step 2: Cool the sample in an atmosphere of −40 ° C. for 30 minutes.

  At each time point when the above cycle was repeated a predetermined number of times shown in Table 1 below, the cutout portion 7C formed in the polarizer 7 included in the sample was observed with an optical microscope.

(Examples 2 to 8, Comparative Example 1)
In the same manner as in Example 1, except that the angle θ formed by the lateral side (first end) of the second laminate with the absorption axis A of the polarizer 7 was adjusted to the angle shown in Table 1 below. The polarizing plates of Examples 2 to 8 and Comparative Example 1 were prepared 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 shown in Table 1 below. As in the case of Example 1, heat cycle tests using the polarizing plates of Examples 2 to 8 and Comparative Example 1 were performed.

  The results of the heat cycle tests of Examples 1 to 8 and Comparative Example 1 are shown in Table 1 below. “A” in the table means that there was no crack in the notch 7 </ b> C of the polarizer 7. “B” means that a minute crack was formed in the notch 7C of the polarizer 7. “C” means that a larger crack than that in the case of “B” was formed in the notch 7C of the polarizer 7. “B” in the row of Comparative Example 1 means that a crack having a length of about 1 mm was formed. “B” in the row of Example 1 means that a crack having a length of about 10 mm was formed.

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

  Examples 9 and 10 and Comparative Example 2 The shape of each polarizer was the same as that of the polarizer 7 shown in FIG. That is, in the case of Examples 9 and 10 and Comparative Example 2, the shape of the cutout portion 7C formed in the first end portion 7e of the polarizer 7 (the lateral side of the second laminate) was substantially a triangle. . Examples 9 and 10 and Comparative Example 2 The shape of each polarizing plate was the same as that of the polarizer 7 shown in FIG. In the case of Examples 9 and 10 and Comparative Example 2, the angle θ was adjusted to the values described in Table 2 below.

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

  In the same manner as in Example 1, Examples 9 and 10 and Comparative Example 2 were subjected to a heat cycle test using the polarizing plates. Examples 9 and 10 and Comparative Example 2 The results of each heat cycle test are shown in Table 2 below.

(Examples 11 to 17)
Examples 11-17 In preparation of each polarizing plate, angle (theta) was adjusted to 45 degrees.

  Examples 11-17 The shape of each polarizer was the same as the shape of the polarizer 7 shown by FIG. That is, in the case of Examples 11 to 17, the shape of the cutout portion 7C formed in the first end portion 7e of the polarizer 7 (lateral side of the second laminate) was substantially a triangle. Examples 11-17 Each polarizing plate had the same shape as that of the polarizer 7 shown in FIG. 13.

  In the case of Examples 11 to 17, the width W of the first end 7e of the polarizer 7 in which the notch 7C was formed was adjusted to a value shown in Table 3 below. The width W is paraphrased as the length of the horizontal side of the polarizing plate (lateral width of the polarizing plate).

  In Examples 11 to 17, 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 portion 7C1 and the corner portion 7C2 was 20 mm. In Examples 11 to 17, Wc / W was a value shown in Table 3 below. In Examples 11 to 17, the length Dc (depth) of the notch 7C in the direction perpendicular to the reference line L was 10 mm. In the case of Examples 11 to 17, the chamfered portion 7C3 was formed in the deep portion (corner portion) of the notched portion 7C. The radius of curvature of the chamfered portion 7C3 of the notch 7C was 0.1 mm. In Examples 11 to 17, the length of the vertical side of the polarizing plate (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 the case of Example 1, Examples 11 to 17 were subjected to heat cycle tests using the respective polarizing plates. In each of the heat cycle tests of Examples 11 to 17, one surface of the polarizer 7 is covered with the second protective film 9 (a film made of a COP resin), and the other surface of the polarizer 7. Was covered with the first protective film 5 (TAC film). The results of each heat cycle test of Examples 11 to 17 are shown in Table 3 below.

(Examples 18 to 20)
In preparation of the 1st laminated body of Examples 18-20, the 1st protective film 5 (TAC film) was not used but the 3rd protective film 3 (PET protect film) was directly piled up on the polarizer 7. FIG.

  Examples 18-20 In preparation of each polarizing plate, angle (theta) was adjusted to 45 degrees.

  Examples 18-20 The shape of each polarizer was the same as the shape of the polarizer 7 shown by FIG. That is, in Examples 18 to 20, the shape of the cutout portion 7C formed in the first end portion 7e of the polarizer 7 (the lateral side of the second laminate) was substantially a triangle. Examples 18-20 The shape of each polarizing plate was the same as the shape of the polarizer 7 shown by FIG.

  In Examples 18 to 20, the width W of the first end 7e of the polarizer 7 in which the notch 7C was formed was adjusted to a value shown in Table 3 below. The width W is paraphrased as the length of the horizontal side of the polarizing plate (lateral 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 portion 7C1 and the corner portion 7C2 was 20 mm. In Examples 18 to 20, Wc / W was a value shown in Table 3 below. In Examples 18 to 20, the length Dc (depth) of the notch 7C in the direction perpendicular to the reference line L was 10 mm. In the case of Examples 18 to 20, the chamfered portion 7C3 was formed in the deep portion (corner portion) of the notched portion 7C. The radius of curvature of the chamfered portion 7C3 of the notch 7C was 0.1 mm. In Examples 18 to 20, the length of the vertical side of the polarizing plate (vertical width of the polarizing plate) was 70 mm.

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

  Similarly to the case of Example 1, Examples 18 to 20 were subjected to heat cycle tests using the respective polarizing plates. As above-mentioned, each Example 18-20 each polarizing plate was not equipped with the 1st protective film 5 (TAC film). Therefore, in each of the heat cycle tests of Examples 18 to 20, one surface of the polarizer 7 was covered with the second protective film 9 (a film composed of a COP resin). The surface of was exposed without being covered with the first protective film 5 (TAC film). Examples 18 to 20 The results of each heat cycle test are shown in Table 3 below.

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

  Examples 21 to 23 and Comparative Example 3 Each polarizer has the same shape as the polarizer shown in FIG. 3 except that the width W of the entire polarizer 7 is longer than the length D of the entire polarizer 7. It was the same as the shape of 7.

  The lateral width W of the entire polarizer 7 is paraphrased as the width of the entire polarizer 7 in the direction parallel to the reference line L. The lateral width W of the entire polarizer 7 may be rephrased as the width of the entire polarizer 7 in the 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 the direction parallel to the reference line L was 170 mm. The vertical width D of the entire polarizer 7 is paraphrased 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 was 100 mm.

  As shown in FIG. 3, in any of Examples 21 to 23 and Comparative Example 3, the notch portion 7 </ b> C formed in the first end portion 7 e (the lateral side of the second laminate) of the polarizer 7. The shape was rectangular. In the case of Examples 21 to 23 and Comparative Example 3, the width Wc of the notch 7C in the direction parallel to the reference line L was a value shown in Table 4 below. In Examples 21 to 23 and Comparative Example 3, Wc / W was a value shown in Table 4 below. In any of Examples 21 to 23 and Comparative Example 3, the length Dc (depth) of the notch 7C in the direction perpendicular to the reference line L was 5 mm.

  Except for the above items, 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 the case of Example 1, Examples 21 to 23 and Comparative Example 3 were subjected to heat cycle tests using the polarizing plates. Examples 21 to 23 and Comparative Example 3 In each heat cycle test, one surface of the polarizer 7 is covered with a second protective film 9 (a film composed of a COP-based resin). The other surface of was covered with the first protective film 5 (TAC film). Examples 21 to 23 and Comparative Example 3 The results of each heat cycle test are shown in Table 4 below.

  The polarizing plate according to the present invention is applied to, for example, a liquid crystal cell or an organic EL device, and is applied as an optical component constituting an image display device such as a liquid crystal television, an organic EL television, or a smartphone.

  1A, 1Aa, 1Ab, 1B, 1Ba, 1Bb, 1C ... Polarizing plate, 3 ... Third protective film, 5 ... First protective film, 7 ... Polarizer, 7C ... Notch, 7C1, 7C2 ... Notch 7C A pair of corners located at both ends of the plate, 7e... End portion of the polarizer (first end portion), 7cr... Crack, 9... Second protective film, 7Cd. ... Adhesive layer, 13 ... Release film, 17e ... Second end of polarizer, 20A, 20B ... Liquid crystal panel, 30A, 30B ... Liquid crystal display device (image display device), L ... Reference line, A ... Absorption axis, E: direction in which the cutout portion 7C extends, S: line segment connecting the pair of corner portions 7C1, 7C2, Sc ... midpoint of the line segment S, θ: angle formed by the reference line L with the absorption axis A, α: cutout An angle formed by the direction E in which the part C extends with the absorption axis A of the polarizer.

The polarizing plate according to one aspect of the present invention includes a film-like polarizer, the concave notch is formed at the end of the polarizer, and the reference line L is located at both ends of the notch. When defined as a straight line connecting a pair of corners, 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 width of the entire polarizer in the direction parallel to the reference line L, and Wc / W is 0. 10 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 °. The angle θ formed by the reference line L and the absorption axis A may be 0 ° or greater and 30 ° or less. Wc / W may be 0.10 or more and 0.80 or less, or 0.40 or more and less than 1.0.

The method for producing a polarizing plate according to one aspect of the present invention includes a step of producing a first laminate including a polarizer film and at least one optical film overlapping the polarizer film, and processing the first laminate. A step of forming a second laminate 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 at the first end portion of the second laminate. , And the reference line L is defined as a straight line connecting a pair of corners located at both ends of the notch, Wc is the width of the notch in a direction parallel to the reference line L, and W Is the width of the entire polarizer film in the direction parallel to the reference line L, and Wc / W is set to 0.1. Adjust to 10 or more and less than 1.0. You may adjust the angle which the 1st end part of a 2nd laminated body makes with the absorption axis A to 0 degree or more and 30 degrees or less. Wc / W may be adjusted to 0.10 or more and 0.80 or less, or 0.40 or more and less than 1.0.

A polarizing plate according to another aspect of the present invention includes a film-like polarizer, and the polarizer has a first end and a second end located on the opposite side of the first end, A concave notch is formed in the first end, the notch extends from the first end toward the second end, and the direction E in which the notch extends extends from the polarizer. Wc is the width of the notch in the direction parallel to the first end, W is the width of the entire polarizer in the direction parallel to the first end, and Wc is not parallel to the absorption axis A. / W is 0. 10 or more and less than 1.0. In other words, in the polarizing plate according to another aspect of the present invention, the angle α formed by the extending direction E of the notch with the absorption axis A of the polarizer is greater than 0 ° and 90 ° or less. Wc / W may be 0.10 or more and 0.80 or less, or 0.40 or more and less than 1.0.

A method for producing a polarizing plate according to another aspect of the present invention includes a step of producing a first laminate including a polarizer film and at least one optical film overlapping the polarizer film, and processing the first laminate. And the process of producing the 2nd laminated body which has the 2nd end part located in the opposite side of the 1st end part and the 1st end part, and the process of forming the concave notch part in the 1st end part The notch is extended from the first end toward the second end, and the direction E in which the notch extends is adjusted to a direction not parallel to the absorption axis A, and Wc is the first W is the width of the notch in the direction parallel to the end, W is the width of the entire polarizer film in the direction parallel to the first end, and Wc / W is 0. Adjust to 10 or more and less than 1.0. In other words, the angle α formed by the extending direction E of the notch with the absorption axis A of the polarizer film (polarizer) is adjusted to be larger than 0 ° and not larger than 90 °. You may adjust the angle which the 1st end part of a 2nd laminated body makes with the absorption axis A to 0 degree or more and 30 degrees or less. Wc / W may be adjusted to 0.10 or more and 0.80 or less, or 0.40 or more and less than 1.0.

Claims (10)

It has 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 a pair of corners located at both ends of the notch,
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 a width of the whole polarizer in a direction parallel to the reference line L,
Wc / W is 0.05 or more and less than 1.0,
Polarizer. The polarizer has a first end and a second end located on the opposite side of the first end;
The notch is formed in 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,
The polarizing plate according to claim 1. It has a film-like 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 in 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 a direction parallel to the first end,
W is the width of the entire polarizer in a direction parallel to the first end,
Wc / W is 0.05 or more and less than 1.0,
Polarizer. A protective film or a protective layer is in close contact with both surfaces of the polarizer,
The polarizing plate as described in any one of Claims 1-3. Of both surfaces of the polarizer, the protective film or the protective layer is in close contact with only one surface,
The polarizing plate as described in any one of Claims 1-3. The deep part of the notch is chamfered,
The polarizing plate as described in any one of Claims 1-5. Including the polarizing plate according to any one of claims 1 to 6,
Image display device. Producing a first laminate including a polarizer film and at least one optical film overlapping the polarizer film;
Processing the first laminate to produce a second laminate having a first end that is not orthogonal to the absorption axis A of the polarizer film;
Forming a concave notch in the first end;
With
When the reference line L is defined as a straight line connecting a pair of corners located at both ends of the notch,
Wc is the width of the notch in the direction parallel to the reference line L;
W is a width of the whole polarizer in a direction parallel to the reference line L,
Adjusting Wc / W to 0.05 or more and less than 1.0,
Manufacturing method of polarizing plate. The second laminate has a second end located on the opposite side of the first end;
Extending the notch portion from the first end portion toward the second end portion, and adjusting a direction E in which the notch portion extends to a direction not parallel to the absorption axis A;
The manufacturing method of the polarizing plate of Claim 8. Producing a first laminate including a polarizer film and at least one optical film overlapping the polarizer film;
Processing the first laminate to produce a second laminate having a first end and a second end located on the opposite side of the first end;
Forming a concave notch in the first end;
With
Extending the notch from the first end toward the second end, and adjusting the direction E in which the notch extends to a direction not parallel to the absorption axis A of the polarizer film;
Wc is the width of the notch in a direction parallel to the first end,
W is the width of the entire polarizer in a direction parallel to the first end,
Adjusting Wc / W to 0.05 or more and less than 1.0,
Manufacturing method of polarizing plate.

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