Laminated body, polarizing plate, method of manufacturing laminated body, method of manufacturing polarizing plate, and method of manufacturing display device

Abstract

A laminate having a polarizer material film and a resin layer formed directly on the polarizer material film, wherein the phase difference Re1 in the in-plane direction of the polarizer material film is greater than 50 nm and the thickness T1 of the polarizer material film is 45 μm or less. The polarizer material film is preferably a polarizer material film obtained by stretching at a specific stretching ratio of X times. A polarizing plate obtained using the laminate, a method for manufacturing the laminate, a method for manufacturing the polarizing plate, and a method for manufacturing a display device are also provided.

Description

Technology Field

[0001] The present invention relates to a laminate, a polarizing plate, a method for manufacturing a laminate, a method for manufacturing a polarizing plate, and a method for manufacturing a display device. Background Technology

[0002] For display devices such as liquid crystal displays and organic electroluminescence (EL) displays, a large display area, light weight, and thin thickness have traditionally been required. Consequently, panels constituting the display devices have also traditionally been required to be thin.

[0003] In display devices, a polarizing plate equipped with a polarizer and a protective film that protects the polarizer is generally used. In order to construct a thin display device, it is required that the polarizing plate be thinner. In particular, since polarizers may shrink in the operating environment of the display device, warping caused by such shrinkage can be a problem in thin, large-area display devices. Therefore, by employing a thin polarizer with a thickness of 10 μm or less, in addition to reducing the thickness of the display device through the reduction of the polarizer thickness itself, a reduction in the occurrence of warping as described above can also be expected.

[0004] However, when attempting to manufacture a polyvinyl alcohol polarizer with such a thin thickness using conventional manufacturing methods, melting of the polarizer occurs frequently. Several methods have been proposed to prevent such melting of the polarizer and to manufacture a polarizing plate containing a thin polarizer.

[0005] For example, Patent Document 1 proposes a method of obtaining a polyvinyl alcohol-based film by attaching an unoriented polyvinyl alcohol-based film to an unoriented high-density polyethylene substrate film to form a laminate, and then stretching the laminate and peeling off the substrate film. Prior art literature

[0006] Japanese Patent Publication No. 2016-505404 (Corresponding Publication: U.S. Patent Application Publication No. 2016 / 084990 Specification) The problem to be solved

[0007] When manufacturing a thin polarizer by the method described in Patent Document 1, a phase difference may occur in the base film after the stretching process due to stretching the laminate at a high stretching ratio. In such cases, it is difficult to use the base film as is as a polarizer protective film, so it is peeled off and discarded, resulting in wasted material.

[0008] Accordingly, we considered manufacturing a polarizing plate using a laminate in which a stretched polyvinyl alcohol resin film and an unstretched substrate film are laminated with a polyvinyl alcohol-based adhesive. However, in this method, wrinkles or voids occurred in the laminate and the polarizing plate as the polyvinyl alcohol-based adhesive permeated into the polyvinyl alcohol resin film after stretching.

[0009] Accordingly, the present invention aims to provide a laminate and a method for manufacturing the same, wherein the resin layer can be used as a protective film, the laminate can be manufactured efficiently even with a thin thickness, and the occurrence of wrinkles or voids is prevented, a polarizing plate using the laminate and a method for manufacturing the same, and a method for manufacturing a display device using the polarizing plate. means of solving the problem

[0010] As a result of conducting a review to solve the above problem, the inventors discovered that the problem can be solved by using a laminate having a polarizer material film having a predetermined phase difference and a predetermined thickness, and a resin layer formed directly on the polarizer material film, and thus completed the present invention.

[0011] Accordingly, according to the present invention, the following [1] to

[21] are provided.

[0012] [1] A laminate having a polarizer material film and a resin layer formed directly on the polarizer material film,

[0013] The in-plane phase difference Re1 of the above polarizer material film is greater than 50 nm, and

[0014] A laminate having a thickness T1 of the polarizer material film of the above-mentioned above of 45 μm or less.

[0015] [2] The above polarizer material film is a film obtained by stretching by a stretching ratio of X times, a laminate described in [1].

[0016] [3] X is a laminate as described in [2], satisfying 1.5 ≤ X ≤ 5.5.

[0017] [4] The in-plane phase difference Re2 of the stretched resin layer is 0 nm or more and 20 nm or less, and

[0018] The stretched resin layer is a stretched product of the resin layer in the stretched laminate, and the stretched laminate is a stretched product of the free end uniaxially stretched laminate at a temperature condition of 50°C to 120°C, as described in any one of [1] to [3].

[0019] [5] A laminate described in any one of [1] to [4] in which the polarizer material film is a polyvinyl alcohol resin film.

[0020] [6] The polyvinyl alcohol resin film described in [5] has a transmittance of 50% or more of light at a wavelength of 550 nm.

[0021] [7] A laminate described in any one of [1] to [6], wherein the resin layer is made of a cycloolefin resin.

[0022] [8] The above cycloolefin resin includes a cycloolefin polymer, and

[0023] The above cycloolefin-based polymer comprises a polymer block [A] having a repeating unit [I] derived from an aromatic vinyl compound as the main component, and

[0024] A laminate described in [7], which is a block copolymer hydride formed by hydrogenating a polymer block [B] composed of repeating units [I] derived from an aromatic vinyl compound and repeating units [II] derived from a chain-type conjugated diene compound, or a polymer block [C] composed of repeating units [II] derived from a chain-type conjugated diene compound.

[0025] [9] The resin layer above is a layer made of resin, and

[0026] The above resin has a melt flow rate of 1 g / 10 min or more, and also has a tensile modulus E of 50 MPa or more and 1200 MPa or less, and

[0027] The above melt flow rate is a value measured at 190°C and a load of 2.16 kg, a laminate described in any one of [1] to [8].

[0028]

[10] A laminate described in any one of [1] to [9], wherein the resin layer contains a plasticizer, a softener, or both.

[0029]

[11] The above plasticizer, softener, or both are one or more selected from ester-based plasticizers and aliphatic hydrocarbon polymers,

[10] of the laminate.

[0030]

[12] A laminate described in any one of [1] to

[11] , wherein the resin layer contains an organometallic compound.

[0031]

[13] A polarizing plate that is a uniaxially elongated laminate as described in any one of [1] ~

[12] .

[0032]

[14] A first process of obtaining a polarizer material film by stretching a fabric film containing the polarizer material, and

[0033] A second process of forming a coating layer by applying a resin to one surface of the above-mentioned polarizer material film, and

[0034] A method for manufacturing a laminate, comprising a third process of drying the coating layer in this order.

[0035]

[15] A method for manufacturing a laminate as described in

[14] , wherein the stretching ratio of the stretching in the first process is X times, and X satisfies 1.5 ≤ X ≤ 5.5.

[0036]

[16] A method for manufacturing a laminate as described in

[14] or

[15] , comprising a fourth process of activating the surface of the polarizer material film before the second process above.

[0037]

[17] As a method for manufacturing a polarizing plate,

[0038] A process of preparing a laminate as described in any one of [1] to

[12] , or manufacturing a laminate by a method of manufacturing a laminate as described in any one of

[14] to

[16] , and

[0039] A fifth process of dyeing the above laminate with a dichroic pigment, and

[0040] A method for manufacturing a polarizing plate, comprising a sixth process of uniaxially stretching the above laminate.

[0041]

[18] A method for manufacturing a polarizing plate as described in

[17] , wherein the stretching ratio in the above 6th process is Z times, and Z satisfies 1.2 ≤ Z ≤ 5.0.

[0042]

[19] A method for manufacturing a polarizer as described in

[17] or

[18] , wherein X and Z satisfy 5.1 ≤ X * Z ≤ 9.0.

[0043]

[20] A method for manufacturing a polarizing plate as described in any one of

[17] to

[19] , comprising a seventh step of laminating a protective film on one or both of the polarizer material film side side and the resin layer side side side of the laminate after the fifth step, the sixth step, or both of the above steps.

[0044]

[21] As a method of manufacturing a display device,

[0045]

[17] A process for manufacturing a polarizing plate by the method of manufacturing a polarizing plate described in any one of

[17] ~

[20] , and

[0046] It includes an 8th process of laminating the above polarizing plate onto a panel, and

[0047] A method for manufacturing a display device in which the above panel is a panel selected from a liquid crystal panel, an organic electroluminescence panel, and a micro LED panel. Effects of the invention

[0048] According to the present invention, a resin layer can be used as a protective film and can be manufactured efficiently even with a thin thickness, and also prevents the occurrence of wrinkles or voids, and provides a laminate and a method for manufacturing the same, a polarizing plate using the laminate and a method for manufacturing the same, and a method for manufacturing a display device using the polarizing plate. Brief explanation of the drawing

[0049] FIG. 1 is a cross-sectional view schematically showing a laminate according to embodiment 1. FIG. 2 is a schematic diagram showing an example of a manufacturing apparatus used in the method for manufacturing a laminate according to Embodiment 1. FIG. 3 is a schematic diagram showing an example of a manufacturing apparatus used in the method for manufacturing a polarizing plate according to Embodiment 1. FIG. 4 is a schematic cross-sectional view showing a polarizing plate manufactured using a laminate according to Embodiment 1. FIG. 5 is a cross-sectional view schematically showing a polarizing plate manufactured by the method of manufacturing a polarizing plate according to embodiment 2. FIG. 6 is a cross-sectional view schematically showing a display device manufactured by the method of manufacturing a display device according to embodiment 3. FIG. 7 is a cross-sectional view schematically showing a display device manufactured by the method of manufacturing a display device according to embodiment 4. Specific details for implementing the invention

[0050] Hereinafter, the present invention will be described in detail by presenting embodiments and examples. However, the present invention is not limited to the embodiments and examples described below, and may be implemented with arbitrary modifications within the scope of the claims of the present invention and their equivalents without departing from the scope of the claims and equivalents thereof.

[0051] In the present invention, a “long” film refers to a film having a length of at least five times its width, preferably ten times or more, and specifically refers to a film having a length such that it is wound into a roll for storage or transport. The upper limit of the ratio of length to width is not specifically limited, but, for example, can be 100,000 times or less.

[0052] In the present invention, the in-plane phase difference Re and the thickness phase difference Rth of the film are calculated according to the equations Re = (nx - ny) × d and Rth = [{(nx + ny) / 2} - nz] × d. Additionally, the Nz coefficient of the film is a value represented by [(nx - nz) / (nx - ny)], which can also be expressed as [(Rth / Re) + 0.5]. Here, nx is the refractive index in the direction of the ground axis within the film (maximum in-plane refractive index), ny is the refractive index in the in-plane direction perpendicular to the ground axis within the film, nz is the refractive index in the thickness direction of the film, and d is the thickness of the film (nm). Unless otherwise noted, the measurement wavelength is 550 nm, which is a representative wavelength in the visible light region.

[0053] [Embodiment 1: Laminate and method of manufacturing the same, polarizing plate and method of manufacturing the same]

[0054] Hereinafter, a laminate of Embodiment 1, which is an embodiment of the present invention, and a method for manufacturing the same, and a polarizing plate using the laminate and a method for manufacturing the same will be described with reference to FIGS. 1 to 4.

[0055] [1. Laminated]

[0056] The laminate of the present invention has a polarizer material film and a resin layer formed directly on the polarizer material film. In the laminate of the present invention, the phase difference Re1 in the in-plane direction of the polarizer material film is greater than 50 nm, and the thickness T1 of the polarizer material film is 45 μm or less.

[0057] As is evident from the context, in the present invention, the “resin layer” is a layer different from the polarizer material film.

[0058] In the present invention, the “resin layer directly formed on the polarizer material film” is a resin layer formed on the surface of a layer of material constituting the polarizer material film, and as a result, in a state of being in direct contact with the surface of the polarizer material film.

[0059] FIG. 1 is an example of a cross-sectional view schematically showing a laminate (10) of Embodiment 1 according to the present invention. As shown in FIG. 1, the laminate (10) of the present embodiment includes a polarizer material film (11) and a resin layer (12) formed on one side (upper side shown) of the polarizer material film (11). The laminate (10) of the present invention is a material for manufacturing a polarizer and a polarizing plate having a polarizer.

[0060] [Polarizer material film]

[0061] A polarizer material film is a film for manufacturing a polarizer (a film for a polarizer). In the present invention, the polarizer material film is a film in which the in-plane phase difference Re1 is greater than 50 nm and the thickness T1 is 45 μm or less. The polarizer material film can be obtained by stretching an unoriented film containing a polarizer material so that the in-plane phase difference Re1 is greater than 50 nm and the thickness T1 is 45 μm or less. The polarizer material film is a (stretched) film containing a polarizer material. In the present invention, a film that is not subjected to stretching treatment to achieve a predetermined phase difference and thickness (an unoriented film containing a polarizer material) as a film for obtaining a polarizer material film is called a "base film." The base film contains a polarizer material.

[0062] In the present invention, the base film is not necessarily limited to any film capable of achieving the purpose of the present invention, but a polyvinyl alcohol resin film is preferred due to its high cost performance.

[0063] In the present invention, the polyvinyl alcohol resin film (hereinafter referred to as "PVA resin film") that can be used as a base film is not necessarily limited, but it is preferable to use one manufactured by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate, due to availability, etc. The polyvinyl alcohol (hereinafter referred to as "PVA") included in the PVA resin film preferably has a degree of polymerization in the range of 500 to 8000 and a degree of saponification of 90 mol% or more, from the view that it has excellent stretchability and polarization performance of the polarizer obtained. Here, the degree of polymerization is the average degree of polymerization measured in accordance with the description in JIS K6726-1994, and the degree of saponification is the value measured in accordance with the description in JIS K6726-1994. A more preferred range for the degree of polymerization is 1000 to 6000, more preferably 1500 to 4000. A more preferred range for the degree of saponification is 95 mol% or more, more preferably 99 mol% or more. PVA may be a copolymer of vinyl acetate and other monomers copolymerizable with vinyl acetate, or a graft polymer.

[0064] In the present invention, the method of producing a PVA resin film that can be used as a base film is not particularly limited and can be produced by any known method. Examples of production methods include a flexible film-making method, a wet film-making method (extrusion into a solvent), a dry-wet film-making method, a gel film-making method (a method of obtaining a PVA resin film by first cooling and gelling an aqueous PVA solution and then extracting and removing the solvent), and a method based on a combination thereof, in which a PVA solution obtained by dissolving PVA in a solvent is used as the film-making stock solution. An additional example of a production method is a melt extrusion film-making method in which molten PVA containing a solvent is used as the film-making stock solution. Among these, the flexible film-making method and the melt extrusion film-making method are preferred in that they yield a PVA resin film with high transparency and low discoloration, and the melt extrusion film-making method is more preferred in that it can obtain a high film-making speed.

[0065] In the present invention, the PVA resin film that can be used as a raw material film preferably contains 0.01 to 30 weight% of a plasticizer, such as a polyhydric alcohol like glycerin, relative to PVA in order to improve mechanical properties or process passability during secondary processing, and also preferably contains 0.01 to 1 weight% of a surfactant, such as an anionic surfactant or a nonionic surfactant, relative to PVA in order to improve handling properties or film appearance.

[0066] A PVA resin film that can be used as a base film may additionally include, if necessary, any other components such as antioxidants, UV absorbers, lubricants, pH adjusters, inorganic fine particles, colorants, preservatives, antifungal agents, polymer compounds other than those mentioned above, and moisture. The PVA resin film may include one or more of the above optional components.

[0067] The thickness of the base film is preferably 60 μm or less, more preferably 45 μm or less, even more preferably 30 μm or less, preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. By having the thickness of the base film greater than or equal to the lower limit of the above range, a polarizing plate having a sufficiently high degree of polarization can be obtained, and by having the thickness of the base film less than or equal to the upper limit of the above range, the resistance to bending of the polarizing plate can be effectively increased.

[0068] The polarizer material film can be a film obtained by stretching. The polarizer material film can be obtained by stretching a base film. Methods of stretching treatment include dry stretching and wet stretching. Since dry stretching requires simpler equipment and processes compared to wet stretching, it is preferable to obtain the polarizer material film by dry stretching. For dry stretching, stretching methods such as tenter stretching, float stretching, and thermal roll stretching can be used. Dry stretching refers to a stretching treatment method performed under a gas atmosphere at a high temperature (e.g., 100°C or higher). Air can be used as the gas in dry stretching.

[0069] When stretching a base film to form a polarizer material film, the stretching conditions can be appropriately selected to obtain a desired polarizer material film. For example, when stretching a base film to form a polarizer material film, the stretching mode can be any mode, such as uniaxial stretching or biaxial stretching. In addition, when the base film is a long film, the stretching direction may be any of the longitudinal direction (a direction parallel to the length direction of the long film), the transverse direction (a direction parallel to the width direction of the long film), and the diagonal direction (a direction that is neither the longitudinal direction nor the transverse direction).

[0070] The polarizer material film can be a film stretched by a stretching ratio X. It is preferable that X satisfies 1.5 ≤ X ≤ 5.5. Such a polarizer material film can be obtained by stretching a base film by a stretching ratio X. In the present invention, X is preferably 1.5 or higher, more preferably 2.0 or higher, even more preferably 2.5 or higher, preferably 5.5 or lower, more preferably 4.5 or lower, and even more preferably 3.5 or lower. That is, it is preferable that the polarizer material film is a film stretched by a stretching ratio of 1.5 times or higher and 5.5 times or lower, more preferable that it is a film stretched by a stretching ratio of 2.0 times or higher and 4.5 times or lower, and even more preferable that it is a film stretched by a stretching ratio of 2.5 times or higher and 3.5 times or lower. If X is set to an upper limit value or lower than the above range, the occurrence of breakage can be prevented when stretching the base film to form a polarizer material film. In addition, if X is set above the lower limit of the above range, the stretching ratio when obtaining a polarizer by stretching the laminate can be lowered. When stretching of the base film is performed by stretching in two or more directions, such as biaxial stretching, the stretching ratio X is the product of the stretching ratios of each stretching.

[0071] When dry-stretching a base film to form a polarizer material film, the stretching temperature is preferably 100°C or higher, more preferably 110°C or higher, while preferably 150°C or lower, more preferably 140°C or lower. By keeping the dry-stretching temperature within the above range, a polarizer material film with a uniform film thickness is obtained.

[0072] The polarizer material film is preferably a PVA resin film. As for the PVA resin film that can be used as the polarizer material film, it is preferable to have a light transmittance of 50% or more for a wavelength of 550 nm (hereinafter, "light transmittance of 550 nm" is also referred to as "light transmittance"). As the PVA resin film, an uncolored film may be used. The light transmittance of such a PVA resin film is preferably 55% or more, more preferably 60% or more, preferably 99% or less, more preferably 97% or less.

[0073] The thickness T1 of the polarizer material film is preferably 45 μm or less, more preferably 35 μm or less, even more preferably 25 μm or less, preferably 5 μm or more, more preferably 7 μm or more, and even more preferably 10 μm or more. By having the thickness of the polarizer material film be less than or equal to the upper limit of the above range, the shrinkage force of the polarizer can be effectively reduced, and by having it be greater than or equal to the lower limit of the above range, a polarizer having a sufficiently high degree of polarization can be obtained.

[0074] The phase difference Re1 in the in-plane direction of the polarizer material film is preferably 50 nm or more, more preferably greater than 50 nm, even more preferably 100 nm or more, particularly preferably 150 nm or more, preferably 1500 nm or less, and more preferably 1000 nm or less. By ensuring that the phase difference Re1 in the in-plane direction of the polarizer material film is greater than or equal to the lower limit of the above range, the stretching ratio when the laminate is stretched to form a polarizer can be suppressed to a low level, thereby maintaining a low phase difference of the resin layer after the stretching process.

[0075] The shape and dimensions of the polarizer material film can be appropriately adjusted according to the desired application. For manufacturing efficiency, it is preferable for the polarizer material film to be a long film.

[0076] [Resin layer]

[0077] The resin layer is a layer composed of resin. The resin layer may be a resin layer formed by applying resin to a polarizer material film. Alternatively, the resin layer may be formed by directly heat-pressing a film-shaped resin onto a polarizer material film. "Direct heat-pressing" onto a polarizer material film means pressing the polarizer material film and the film-shaped resin forming the resin layer without interposing an adhesive or pressure-sensitive adhesive between the polarizer material film and the resin layer.

[0078] In the present invention, the resin constituting the resin layer is preferably a resin having flexibility capable of stretching at a high stretching ratio (e.g., 6.0 times) at a low temperature (e.g., 50 to 120°C). Examples of such resins include a cycloolefin resin containing a cycloolefin polymer, and a resin having a melt flow rate of 1 g / 10 min or more and a tensile modulus E of 50 MPa or more and 1200 MPa or less. The melt flow rate referred to herein is a value measured at 190°C and a load of 2.16 kg. Hereinafter, the "melt flow rate measured at 190°C and a load of 2.16 kg" is also simply referred to as "MFR".

[0079] [profit]

[0080] A cycloolefin resin is a resin containing a cycloolefin polymer. As for the cycloolefin polymer included in the cycloolefin resin, a block copolymer hydride is preferred, which is obtained by hydrogenating a block copolymer [D] composed of a polymer block [A] having a repeating unit [I] derived from an aromatic vinyl compound as the main component, a polymer block [B] having a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain-type conjugated diene compound as the main component, or a polymer block [C] having a repeating unit [II] derived from a chain-type conjugated diene compound as the main component. Examples of such block copolymer hydrides include polymers described in WO2000 / 32646, WO2001 / 081957, Japanese Patent Publication No. 2002-105151, Japanese Patent Publication No. 2006-195242, Japanese Patent Publication No. 2011-13378, WO2015 / 002020, etc. For the cycloolefin resin, it is preferable that the MFR is 1 g / 10 min or more and the tensile modulus E is 50 MPa or more and 1200 MPa or less, but the MFR, tensile modulus E, or both may be outside the above ranges.

[0081] In addition, in the present invention, the “polymer block [A] having repeating unit [I] derived from an aromatic vinyl compound as the main component” may be the “polymer block [A] containing more than 60 mass% of repeating unit derived from an aromatic vinyl compound.” The “polymer block [B] having repeating unit [I] derived from an aromatic vinyl compound and repeating unit [II] derived from a chain-type conjugated diene compound as the main component” may be the “polymer block [B] containing more than 60 mass% of the sum of repeating unit [I] derived from an aromatic vinyl compound and repeating unit [II] derived from a chain-type conjugated diene compound.” The “polymer block [C] having repeating unit [II] derived from a chain-type conjugated diene compound as the main component” may be the “polymer block [C] containing more than 60 mass% of repeating unit derived from a chain-type conjugated diene compound.”

[0082] In the present invention, the resin constituting the resin layer is preferably a resin having a melt flow rate of 1 g / 10 min or more and a tensile modulus E of 50 MPa or more and 1200 MPa or less. The resin having an MFR of 1 g / 10 min or more and a tensile modulus E of 50 MPa or more and 1200 MPa or less is preferably a cycloolefin-based resin, but may be a resin other than a cycloolefin-based resin.

[0083] The MFR of the resin is preferably 1 g / 10 min or more, more preferably 3 g / 10 min or more, even more preferably 5 g / 10 min or more, preferably 300 g / 10 min or less, and more preferably 100 g / 10 min or less. By making the MFR of the resin above a lower limit value, the phase difference can be suppressed to be small when used as a polarizer, and by making the MFR below an upper limit value, heat resistance can be increased.

[0084] The MFR of the resin can be measured based on JIS-K-7210 using a melt indexer under conditions of a temperature of 190°C and a load of 2.16 kg.

[0085] In the present invention, the tensile modulus E of the resin constituting the resin layer is preferably 50 MPa or more, more preferably 100 MPa or more, even more preferably 200 MPa or more, preferably 1200 MPa or less, more preferably 1000 MPa or less, and even more preferably 800 MPa or less. By making the tensile modulus E of the resin greater than or equal to the lower limit value, the phase difference of the resin layer is reduced when the laminate is stretched to form a polarizer, and by making it less than or equal to the upper limit value, the occurrence of fracture of the resin layer when the laminate is stretched can be prevented.

[0086] The tensile modulus can be measured based on JIS K7127 using a tensile testing machine (manufactured by Instron Japan Company Limited, product name “Electromechanical Universal Material Testing Machine (5564)”).

[0087] [Plasticizers and Softeners]

[0088] In the present invention, the resin constituting the resin layer preferably contains a plasticizer, a softener, or both. By containing a plasticizer, a softener, or both, the phase difference occurring in the resin layer can be reduced when a polarizing plate is obtained by stretching the laminate.

[0089] As plasticizers and softeners, those that can be uniformly dissolved or dispersed in the resin constituting the resin layer may be used. Specific examples of plasticizers and softeners include ester-based plasticizers composed of a polyhydric alcohol and a monohydric carboxylic acid (hereinafter referred to as "polyhydric alcohol ester-based plasticizer"), ester-based plasticizers composed of a polyhydric acid and a monohydric alcohol (hereinafter referred to as "polyhydric acid ester-based plasticizer"), phosphate ester-based plasticizers, carbohydrate ester-based plasticizers, and other polymer softeners.

[0090] Examples of polyhydric alcohols that are raw materials for ester-based plasticizers preferably used in the present invention are not particularly limited, but ethylene glycol, glycerin, and trimethylolpropane are preferred.

[0091] Examples of polyhydric alcohol ester plasticizers include ethylene glycol ester plasticizers, glycerin ester plasticizers, and other polyhydric alcohol ester plasticizers.

[0092] Examples of polycarboxylic acid ester-based plasticizers include dicarboxylic acid ester-based plasticizers and other polycarboxylic acid ester-based plasticizers.

[0093] Examples of phosphate ester-based plasticizers include, specifically, alkyl phosphate esters such as triacetyl phosphate and tributyl phosphate; cycloalkyl phosphate esters such as tricyclopentyl phosphate and cyclohexyl phosphate; and aryl phosphate esters such as triphenyl phosphate and tricresyl phosphate.

[0094] As carbohydrate ester-based plasticizers, specifically, glucose pentaacetate, glucose pentapropionate, glucose pentabutyrate, saccharose octaacetate, saccharose octabenzoate, etc. are preferably cited, and among these, saccharose octaacetate is more preferred.

[0095] Polymer softeners include, specifically, aliphatic hydrocarbon polymers, alicyclic hydrocarbon polymers, acrylic polymers such as polyethyl acrylate, polymethyl methacrylate, copolymers of methyl methacrylate and methyl methacrylate-2-hydroxyethyl methacrylate, copolymers of methyl methacrylate, methyl acrylate and methyl methacrylate-2-hydroxyethyl methacrylate; vinyl polymers such as polyvinyl isobutyl ether and poly N-vinylpyrrolidone; styrene polymers such as polystyrene and poly 4-hydroxystyrene; polyesters such as polybutylene succinate, polyethylene terephthalate, and polyethylene naphthalate; polyethers such as polyethylene oxide and polypropylene oxide; polyamides, polyurethanes, and polyureas.

[0096] Specific examples of aliphatic hydrocarbon polymers include low molecular weight polymers such as polyisobutylene, polybutene, poly-4-methylpentene, poly-1-octene, and ethylene-α-olefin copolymer, and their hydrides; low molecular weight polymers such as polyisoprene and polyisoprene-butadiene copolymer, and their hydrides. From the perspective of being easily uniformly dissolved or dispersed in a cycloolefin resin, it is preferable that the aliphatic hydrocarbon polymer has a number average molecular weight of 300 to 5,000.

[0097] These polymer softeners may be homopolymers consisting of one repeating unit or copolymers having multiple repeating structures. In addition, two or more of the above polymers may be used in combination.

[0098] In the present invention, the plasticizer, the softener, or both of these (hereinafter also referred to as "plasticizer, etc.") is preferably one or more selected from ester-based plasticizers and aliphatic hydrocarbon polymers in that they have particularly excellent compatibility with the resin constituting the resin layer.

[0099] The proportion of plasticizers, etc. in the resin layer is preferably 0.2 parts by weight or more, more preferably 0.5 parts by weight or more, and even more preferably 1.0 parts by weight or more, with respect to 100 parts by weight of the resin constituting the resin layer, while preferably 50 parts by weight or less, and more preferably 40 parts by weight or less. By keeping the proportion of plasticizers, etc. within the above range, the resin layer can be made such that the expression of phase difference is sufficiently low even after undergoing a manufacturing process of a polarizing plate including stretching treatment.

[0100] [Organometallic compounds]

[0101] In the present invention, it is preferable that the resin layer contains an organometallic compound. By including an organometallic compound, the occurrence of delamination of the resin layer can be more effectively suppressed when the laminate is stretched at a high stretching ratio (e.g., wet stretching at a stretching ratio of 6.0).

[0102] An organometallic compound is a compound comprising at least one of a chemical bond between a metal and carbon and a chemical bond between a metal and oxygen, and is a metal compound having an organic group. Examples of organometallic compounds include organosilicon compounds, organotitanium compounds, organoaluminum compounds, and organozirconium compounds. Among these, organosilicon compounds, organotitanium compounds, and organozirconium compounds are preferred due to their excellent reactivity with polyvinyl alcohol, and organosilicon compounds are more preferred. One or more organometallic compounds may be used in combination.

[0103] Examples of organometallic compounds include, for instance, organosilicon compounds represented by the following formula (1), but are not limited thereto.

[0104] R 1 a Si(OR 2 ) 4-a (1)

[0105] (In Equation (1), R 1 and R 2 Each represents a group selected independently from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an epoxy group, an amino group, a thiol group, an isocyanate group, and an organic group having 1 to 10 carbon atoms, and a represents an integer from 0 to 4.

[0106] In equation (1), R 1 Preferred examples include epoxy groups, amino groups, thiol groups, isocyanate groups, vinyl groups, acrylic groups, aryl groups, -CH2OC n H 2n+1 (n represents an integer from 1 to 4.) Examples include alkyl groups with 1 to 8 carbon atoms.

[0107] Also, in Equation (1), R 2 Preferred examples include hydrogen atoms, vinyl groups, aryl groups, acrylic groups, alkyl groups having 1 to 8 carbon atoms, -CH2OC nH 2n+1 Examples include (n represents an integer from 1 to 4).

[0108] Examples of organosilicon compounds include epoxy-based organosilicon compounds such as 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, amino-based organosilicon compounds such as 3-aminopropyltrimethoxysilane and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, isocyanurate-based organosilicon compounds such as tris-(trimethoxysilylpropyl)isocyanurate, mercapto-based organosilicon compounds such as 3-mercaptopropyltrimethoxysilane, and isocyanate-based organosilicon compounds such as 3-isocyanatepropyltriethoxysilane.

[0109] Examples of organic titanium compounds include titanium alkoxides such as tetraisopropyltitanate, titanium chelates such as titanium acetylacetonate, and titanium acylates such as titanium isostearate.

[0110] Examples of organic zirconium compounds include zirconium alkoxides such as normal propyl zirconate, zirconium chelates such as zirconium tetraacetylacetonate, and zirconium acylates such as zirconium stearate.

[0111] Examples of organoaluminum compounds include aluminum alkoxides such as aluminum secondary butoxide and aluminum chelates such as aluminum triacetylacetonate.

[0112] The proportion of the organometallic compound in the resin layer is preferably 0.005 parts by weight or more, more preferably 0.01 parts by weight or more, and even more preferably 0.03 parts by weight or more, with respect to 100 parts by weight of the resin constituting the resin layer, while preferably 1.0 parts by weight or less, and more preferably 0.5 parts by weight or less. By keeping the proportion of the organometallic compound within the above range, the occurrence of delamination of the resin layer can be more effectively suppressed when the laminate is wet-stretched at a high magnification (e.g., a stretching magnification of 6.0).

[0113] [Optional ingredient]

[0114] The resin layer may include optional components in addition to resins, plasticizers, organometallic compounds, etc. Examples of optional components include stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers; resin modifiers such as lubricants; coloring agents such as dyes or pigments; and antistatic agents. These formulation agents may be used individually or in combination of two or more, and the amount of each formulation is appropriately selected.

[0115] [Thickness of the resin layer]

[0116] The thickness of the resin layer in the laminate is preferably 3 μm or more, more preferably 5 μm or more, preferably 60 μm or less, and more preferably 20 μm or less. By having the thickness of the resin layer greater than or equal to the lower limit of the above range, the melting of the polarizer in the polarizing plate making process can be effectively prevented, and by having the thickness less than or equal to the upper limit of the above range, the phase difference generated in the resin layer can be reduced when the laminate is stretched to obtain a polarizing plate.

[0117] [Re2 of the resin layer]

[0118] It is preferable that the Re2 of the resin layer be 0 nm or more and 20 nm or less. More preferably, Re2 is 0 nm or more, more preferably 10 nm or less, and particularly preferably 5 nm or less. By having Re2 below the upper limit value, the phase difference that appears in the resin layer can be reduced when the laminate (10) is stretched to form a polarizer.

[0119] Re2 is the in-plane phase difference of the stretched resin layer when the laminate (10) is stretched uniaxially by a free end 6.0 times under a temperature condition of 50°C to 120°C to form a stretched laminate, and thereby the resin layer in the laminate is made into a stretched resin layer, that is, a stretched product of the resin layer. That is, Re2 is not the phase difference of the resin layer itself in the laminate, but the phase difference that occurs in the stretched product of the resin layer after a specific stretching treatment is applied to the laminate.

[0120] The stretching temperature for obtaining such a stretched material may be any temperature within the range of 50°C to 120°C. Accordingly, multiple operating conditions for stretching to obtain a stretched material can be considered. If, by any one of these multiple operating conditions, the stretched material exhibits a phase difference of 0 nm or more and 20 nm or less, the laminate satisfies the above requirements.

[0121] However, it is preferable that the stretched material exhibits a phase difference of 0 nm or more and 20 nm or less by all of the above-mentioned operating conditions. In that case, in the manufacture of a polarizer using the laminate for a polarizer according to the present invention, a high degree of freedom in setting stretching conditions can be obtained.

[0122] Generally, within the temperature range, a larger phase difference is exhibited when the stretching temperature is lower. Therefore, if both the phase difference of the stretched material due to stretching at 50°C and the phase difference of the stretched material due to stretching at 120°C are within the range of 0 nm or more and 20 nm or less, it can be determined that the stretched material exhibits a phase difference of 0 nm or more and 20 nm or less by all of the above multiple operating conditions.

[0123] [2. Method for manufacturing a laminate]

[0124] The method for manufacturing a laminate according to the present embodiment comprises, in this order, a first step of stretching a base film containing a polarizer material to obtain a polarizer material film, a second step of applying a resin to one surface of the polarizer material film to form a coating layer, and a third step of drying the coating layer formed in the second step.

[0125] In addition, the method for manufacturing the laminate may include a fourth process of activating the surface of the polarizer material film before the second process.

[0126] [Laminate manufacturing device]

[0127] FIG. 2 is a schematic diagram showing an example of a manufacturing apparatus (200) used in a method for manufacturing a laminate according to the present embodiment. The manufacturing apparatus (200) comprises a unwinding apparatus (201), a coating apparatus (202), a winding apparatus (203), a stretching apparatus (204), a processing apparatus (205) for performing activation treatment, and a drying apparatus (206). A1 is the conveying direction.

[0128] [Method for manufacturing a laminate]

[0129] As shown in FIG. 2, a raw material film (1) unwound from a unwinding device (201) is conveyed to a stretching device (204), and a stretching process is performed in the stretching device (204) to obtain a polarizer material film (11) (first process). The polarizer material film (11) is conveyed to a processing device (205), and an activation process (fourth process) is performed in the processing device (205). Afterward, a coating layer is formed in a coating device (202) (second process), and a drying process (third process) is performed in a drying device (206) to obtain a laminate (10). The manufactured laminate (10) can be wound by a winding device (203) to form a roll shape and provided for an additional process. Each process will be described below.

[0130] [Process 1]

[0131] The first process is a process of obtaining a polarizer material film by stretching a base film containing a polarizer material.

[0132] In the first process, the stretching treatment of the base film is preferably performed under the conditions and methods (method of stretching treatment, mode of stretching, stretching ratio, stretching temperature) described in the [Polarizer material film] section of [1. Laminate]. Specifically, in the first process, it is preferable that the stretching ratio of the base film is X times, and that X satisfies 1.5 ≤ X ≤ 5.5. A more preferred range for X is as described in the [Polarizer material film] section of [1. Laminate].

[0133] [Process 2]

[0134] The second process is a process of forming a coating layer by applying a resin to one surface of a polarizer material film (11). The method of applying the resin to the polarizer material film (11) (coating method) is not particularly limited, but is preferably one or more methods selected from, for example, solution coating, emulsion coating, or melt extrusion coating, and solution coating is more preferable in that high-speed coating is possible and a resin layer with a uniform film thickness is obtained.

[0135] When forming a coating layer by solution coating, the resin used to form the coating layer and the components added as needed are dissolved in a solvent to form a resin composition, and said resin composition is applied to a polarizer material film (11). That is, the phrase “apply resin” includes both cases: applying only resin, and applying a resin composition containing resin and other components.

[0136] [Process 3]

[0137] The third process is a process of drying the coating layer formed in the second process. By performing the third process, a resin layer (12) is formed on one side of the polarizer material film (11).

[0138] In the third process, it is preferable to dry the coating layer in a dryer at a temperature of 50°C to 120°C for 0.5 minutes to 10 minutes. The drying temperature of the coating layer is more preferably 60°C or higher, even more preferably 70°C or higher, even more preferably 100°C or lower, and even more preferably 90°C or lower. By setting the drying temperature above a lower limit, the drying time can be shortened, and by setting the drying temperature below an upper limit, crystallization of the polarizer material film can be suppressed.

[0139] [Process 4]

[0140] The fourth process is a process of activating the surface of a polarizer material film before the second process. In the present invention, the fourth process is an optional process, and the manufacturing method of the present invention may or may not include the fourth process. In the fourth process, by activating the surface of the polarizer material film, plasticizers that have bleed onto the surface of the polarizer material film are removed, and by oxidizing the surface of the polarizer material film, the adhesion of the resin layer is increased, thereby suppressing the peeling of the resin layer when forming the resin layer.

[0141] Methods of activation treatment include, for example, corona treatment, plasma treatment, saponification treatment, primer treatment, anchor coating treatment, etc.

[0142] There is no limitation on the timing of performing the fourth process as long as it is before the second process, and if the heat treatment process described later is performed, it may be performed at any time before the heat treatment process, after the heat treatment process, or simultaneously with the heat treatment process. Since there is a possibility that plasticizers, etc. contained in the polarizer material film may bleed onto the surface of the polarizer material film due to the heat treatment process, it is particularly preferable to perform the fourth process after the heat treatment process.

[0143] [Heating Process]

[0144] The heat treatment process is a process of heat-treating the polarizer material film before the second process. In the present invention, the heat treatment process is an optional process, and the manufacturing method of the present invention may or may not include the heat treatment process. By heat-treating the polarizer material film in the heat treatment process, wrinkles present in the polarizer material film can be removed, thereby improving flatness. By smoothing the polarizer material film, the precision of the film thickness of the resin layer formed in the second process can be improved. The heating temperature of the polarizer material film is preferably 50°C or higher, more preferably 60°C or higher, preferably 100°C or lower, more preferably 90°C or lower.

[0145] [Uses of Laminated Materials]

[0146] The laminate (10) of the present invention is a material for manufacturing a polarizing plate. The laminate can become a polarizing plate after undergoing treatments such as stretching and dyeing. When the laminate (10) is used as a material for a polarizing plate, the laminate wound by the winding device (203) shown in FIG. 2 may be used as is, or a separator film may be laminated onto the resin layer (12) of the laminate wound by the winding device (203), wound into a roll shape to form a laminate film roll, and then used. Below, a polarizing plate of the present embodiment using the laminate (10) of the present embodiment will be described.

[0147] [3. Polarizer]

[0148] [outline]

[0149] The polarizing plate of the present invention is obtained by uniaxially stretching the laminate of the present invention. FIG. 3 is a schematic diagram showing an example of a manufacturing apparatus for manufacturing a polarizing plate using a laminate according to the present embodiment. FIG. 4 is a cross-sectional view schematically showing a polarizing plate manufactured using a laminate according to the present embodiment.

[0150] [Polarizing plate]

[0151] The polarizing plate (100) of the present embodiment is a polarizing plate obtained by uniaxially stretching the laminate of the present embodiment. As shown in FIG. 4, in the polarizing plate (100), a resin layer (112) is laminated on one side (upper side shown) of a polarizer material film (111).

[0152] [Characteristics of each layer in a polarizer]

[0153] The thickness of the polarizer material film (111) in the polarizing plate (100) is preferably 30 μm or less, more preferably 20 μm or less, more preferably 3 μm or more, and more preferably 5 μm or more. By having the thickness below the upper limit, the thickness of the polarizing plate can be reduced, and by having the thickness above the lower limit, a polarizing plate having a sufficiently high degree of polarization can be obtained.

[0154] The phase difference in the in-plane direction of the resin layer in the polarizer is preferably 20 nm or less, more preferably 15 nm or less, even more preferably 10 nm or less, and more preferably 0 nm or more. By keeping the phase difference in the in-plane direction of the resin layer in the polarizer within the above range, black color shift can be suppressed when the polarizer is mounted on a liquid crystal display device.

[0155] [4. Method for manufacturing a polarizing plate]

[0156] [outline]

[0157] The method for manufacturing a polarizing plate according to the present invention is a method for manufacturing a polarizing plate using the laminate of the present invention or a laminate obtained by the method for manufacturing the laminate of the present invention. The method for manufacturing a polarizing plate according to the present invention includes a fifth step of dyeing the laminate with a dichroic pigment and a sixth step of uniaxially stretching the laminate. That is, the method for manufacturing a polarizing plate according to the present invention includes a process of manufacturing the laminate of the present invention by any method, or a process of manufacturing the laminate by the method for manufacturing the laminate of the present invention, a fifth step of dyeing the laminate with a dichroic pigment, and a sixth step of uniaxially stretching the laminate.

[0158] In addition, the method for manufacturing a polarizing plate according to the present invention may include a seventh step of laminating a protective film to one or both of the polarizer material film side surface and the resin layer side surface of the laminate after passing through the fifth step, the sixth step, or both thereof. The seventh step is an optional step, and in this embodiment, an example of manufacturing a polarizing plate by a manufacturing method that does not include the seventh step will be described.

[0159] [Device for manufacturing polarizing plates]

[0160] As shown in FIG. 3, a manufacturing apparatus (300) for manufacturing a polarizing plate comprises a winding apparatus (301, 307), a processing apparatus (302 to 305), a drying apparatus (306), a bonding apparatus (308), and a winding apparatus (310).

[0161] [Method for manufacturing a polarizing plate]

[0162] In this embodiment, the laminate (10) unwound from the unwinding device (301) is returned to the processing devices (302 to 305) to perform a dyeing treatment (5th process) in which the laminate (10) is dyed with a dichroic pigment and a stretching treatment (6th process) in which the laminate is uniaxially stretched. After performing these treatments, the laminate is dried in the drying device (306) to obtain a polarizing plate (100). Each process will be described in detail below.

[0163] [Process 5]

[0164] The fifth process is a process of dyeing the laminate (10) with a dichroic dye. In this embodiment, in the fifth process, the polarizer material film of the laminate is dyed. In the present invention, it is preferable that the polarizer material film included in the laminate undergoing the fifth process be undyed, but the dyeing of the polarizer material film may be performed on the polarizer material film before forming the laminate.

[0165] Examples of dichroic pigments (dichroic materials) used to dye the laminate in the fifth process include iodine and organic dyes. The dyeing method using these dichroic pigments is optional. For example, dyeing may be performed by immersing a layer of the polarizer material film in a dyeing solution containing a dichroic pigment. Furthermore, when using iodine as the dichroic pigment, the dyeing solution may contain an iodide, such as potassium iodide, to increase dyeing efficiency. Although there are no particular restrictions on the dichroic pigment, when the polarizer is used in a display device for vehicle mounting, organic dyes are preferred as the dichroic pigment.

[0166] [Process 6]

[0167] The sixth process is a process of uniaxially stretching the laminate. The method of stretching the laminate is not particularly limited, but wet stretching is preferred. The sixth process may be performed at any time before the fifth process, after the fifth process, or simultaneously with the fifth process. Additionally, the sixth process may be performed multiple times by dividing it at any time before the fifth process, after the fifth process, or simultaneously with the fifth process. The stretching process may be performed once or two or more times.

[0168] In the sixth process, the elongation ratio of the laminate is Z times, and Z can be set to 1.2 ≤ Z ≤ 5.0. Z is preferably 1.2 or higher, more preferably 1.5 or higher, preferably 5.0 or lower, and more preferably 4.0 or lower. If the elongation ratio of the laminate is set to the upper limit of the above range or lower, the expression of phase difference of the resin layer can still be kept low and the occurrence of breakage of the polarizer can be prevented even after undergoing a manufacturing process of the polarizer including stretching treatment, and if the elongation ratio is set to the lower limit of the above range or higher, a polarizer with sufficient polarization performance can be obtained. When stretching the laminate two or more times, it is preferable that the total elongation ratio, expressed as the product of the elongation ratios of each time, be within the above range.

[0169] It is preferable that the stretching ratio X of the base film in the first process and the stretching ratio Z of the laminate in the sixth process satisfy 5.1 ≤ X * Z ≤ 9.0. X * Z is the product of X and Z (the product of the stretching ratios). X * Z is preferably 5.1 or higher, more preferably 5.5 or higher, preferably 9.0 or lower, and more preferably 7.0 or lower. By keeping X * Z below the upper limit of the above range, the expression of the phase difference of the resin layer is kept low even after undergoing a manufacturing process of the polarizer including stretching treatment, thereby preventing the occurrence of breakage of the polarizer. By keeping X * Z above the lower limit of the above range, a polarizer having sufficient polarization performance can be obtained.

[0170] The stretching temperature of the laminate is not subject to any particular limitations, but is preferably 30°C or higher, more preferably 40°C or higher, particularly preferably 50°C or higher, preferably 140°C or lower, more preferably 90°C or lower, and particularly preferably 70°C or lower. Stretching can be performed smoothly by the stretching temperature being above the lower limit of the above range, and effective orientation can be achieved by stretching by being below the upper limit of the above range. The above stretching temperature range is preferably used for either dry stretching or wet stretching, but is particularly preferred in the case of wet stretching.

[0171] The stretching treatment of the laminate may be performed using any of the following: longitudinal stretching treatment, which stretches in the film length direction; transverse stretching treatment, which stretches in the film width direction; or oblique stretching treatment, which stretches in an oblique direction that is neither parallel nor perpendicular to the film width direction. For the stretching treatment of the laminate, free-end uniaxial stretching is preferred, and free-end uniaxial stretching in the longitudinal direction is more preferred.

[0172] [Drying Process]

[0173] The drying process is a process for drying the laminate that has undergone the fifth and sixth processes. In the present invention, the drying process is an optional process. In the drying process, it is preferable to dry the laminate in a dryer at a temperature of 50°C to 100°C for 0.5 minutes to 10 minutes. The drying temperature of the laminate is more preferably 60°C or higher, and more preferably 90°C or lower. By setting the drying temperature above a lower limit, the drying time can be shortened, and by setting the drying temperature below an upper limit, cracking of the polarizer material film can be prevented. The drying time of the laminate is more preferably 1 minute or higher, and more preferably 5 minutes or lower. By setting the drying time above a lower limit, the drying of the laminate is sufficient, and by setting it below an upper limit, cracking of the polarizer material film in the laminate can be prevented.

[0174] In the case of a thin film polarizer made solely of conventional PVA resin, cracks may occur after the drying process. However, since the polarizer of the present embodiment is manufactured using a laminate having a polarizer material film and a resin layer directly laminated to the polarizer material film, the occurrence of cracks in the polarizer can be suppressed even after the drying process.

[0175] [5. Function and Effects of the Present Embodiment]

[0176] In the present embodiment, a polarizing plate is manufactured by stretching a laminate having a polarizer material film having a predetermined phase difference Re1 and a small thickness T1, and a resin layer formed directly on the polarizer material film. This allows for a lower stretching ratio when manufacturing a polarizing plate by stretching the laminate. As a result, the expression of a phase difference in the resin layer after the laminate is stretched can be suppressed. Consequently, according to the present embodiment, the resin layer can be used as a protective film on one side of the polarizer material film without peeling it off, and the amount of wasted material can be reduced. Therefore, the resin layer can also be used as a protective film, and the polarizing plate can be manufactured efficiently even with a thin thickness. Thus, a laminate for a polarizing plate and a method for manufacturing the same, a polarizing plate using the said laminate and a method for manufacturing the same, and a method for manufacturing a display device using the said polarizing plate can be provided.

[0177] In addition, in the laminate (10) of the present embodiment, the resin layer (12) is formed directly on the polarizer material film (11) without interposing an adhesive or the like, so the occurrence of wrinkles and voids caused by the seepage of the adhesive or the like can be prevented. As a result, according to the present embodiment, a laminate that prevents the occurrence of wrinkles and voids and a method for manufacturing the same, a polarizing plate and a method for manufacturing the same, and a method for manufacturing a display device can be provided.

[0178] In addition, according to the present embodiment, since no other material is interposed between the resin layer (12) and the polarizer material film (11), the fracture suppression effect is excellent, and it is also possible to prevent environmental contamination by other substances in the production environment or contamination (incorporation of foreign substances) into the product.

[0179] [Embodiment 2: Polarizing plate and method of manufacturing the same]

[0180] Hereinafter, a polarizing plate (120) according to Embodiment 2 and a method for manufacturing the same will be described with reference to FIGS. 3 and FIGS. 5. The polarizing plate (120) according to this embodiment is manufactured using the polarizing plate (100) according to Embodiment 1. The same reference numerals are used for configurations and aspects identical to those in Embodiment 1, and redundant descriptions are omitted.

[0181] [Polarizing plate]

[0182] FIG. 5 is a schematic cross-sectional view of a polarizing plate (120) according to embodiment 2 of the present invention. In this polarizing plate (120), as shown in FIG. 5, a resin layer (112) is laminated on one side (upper side shown) of a polarizer material film (111), and a protective film (115) is laminated on the other side (lower side shown) of the polarizer material film (111).

[0183] [Method for manufacturing a polarizing plate]

[0184] The manufacturing method of the polarizing plate (120) of the present embodiment includes a seventh step of laminating a protective film to the side of the polarizer material film of the laminate after undergoing the fifth and sixth steps. This will be explained in detail below.

[0185] In the manufacturing method of the polarizing plate (120) of the present embodiment, a polarizing plate (100) obtained by drying in a drying device (306) after dyeing the polarizer material film (11) of the laminate (10) and stretching the laminate uniaxially (6th process) is used.

[0186] As shown in FIG. 3, the polarizing plate (120) is obtained by transferring the polarizing plate (100), obtained through dyeing treatment (process 5) and stretching treatment (process 6), to a lamination device (308), and laminating a protective film (115) unwound from a unwinding device (307) onto the side of the polarizer material film of the laminate (process 7). The obtained polarizing plate (120) can be wound by a winding device (310) to form a roll shape and provided for an additional process.

[0187] The protective film (115) used in the 7th process may be a film made of one or more resins selected from cycloolefin resin, acrylic resin, polyethylene terephthalate resin, and triacetylcellulose resin.

[0188] Lamination of the protective film (115) to the polarizing plate (100) is not subject to any special restrictions and may be performed by methods such as heat pressing (see FIG. 5). Lamination of the protective film (115) to the polarizing plate (100) may be performed by interposing an adhesive or a pressure-sensitive adhesive. In the polarizing plate after the fifth and sixth processes, since the polarizer material film is cured, the problem of wrinkles caused by the adhesive seeping in is unlikely to occur.

[0189] Examples of adhesives and pressure-sensitive adhesives used for laminating a protective film and a polarizer include, for instance, acrylic adhesives, epoxy adhesives, urethane adhesives, polyester adhesives, polyvinyl alcohol adhesives, polyolefin adhesives, modified polyolefin adhesives, polyvinylalkyl ether adhesives, rubber adhesives, vinyl chloride-vinyl acetate adhesives, SEBS (styrene-ethylene-butylene-styrene copolymer) adhesives, ethylene-styrene copolymers, ethylene-styrene copolymers, acrylic acid ester adhesives such as ethylene-(meth)acrylate copolymers and ethylene-(meth)acrylate ethyl copolymers.

[0190] The polarizing plate (120) of this embodiment is manufactured by stretching a laminate having a polarizer material film and a resin layer directly laminated on the surface of the polarizer material film, just like the polarizing plate of embodiment 1, and thus has the same functional effect as embodiment 1.

[0191] In addition, according to the present embodiment, since a protective film (115) is provided on the side where the resin layer (112) of the polarizer material film (111) is not laminated, the effect of preventing scratches or the like from forming on the surface of the polarizer material film (111) is also exhibited.

[0192] [Overview of the method for manufacturing the display device of the present invention]

[0193] A polarizing plate manufactured using the laminate of the present invention can be used as a material for display devices such as liquid crystal display devices, organic EL display devices, inorganic EL display devices, and micro LED display devices.

[0194] The method for manufacturing a display device of the present invention is a method for manufacturing a display device using a polarizing plate obtained by the method for manufacturing a polarizing plate of the present invention, and includes an eighth step of laminating the polarizing plate onto a panel. In the method for manufacturing a polarizing plate of the present invention, the panel is a panel selected from a liquid crystal panel, an organic EL panel, and a micro LED panel.

[0195] [Embodiment 3: Method for manufacturing a display device]

[0196] Hereinafter, a display device (400) according to Embodiment 3, which is equipped with a polarizing plate (100) manufactured using the laminate (10) of Embodiment 1, will be described with reference to FIGS. 4 and 6.

[0197] The method for manufacturing a display device according to the present embodiment includes a process (the 8th process) of laminating a polarizing plate (100) shown in FIG. 4 onto a panel. In the present embodiment, an example of manufacturing a liquid crystal display device using a liquid crystal panel as the panel is described.

[0198] Typically, a liquid crystal display device comprises a light source, a light source-side polarizer, a liquid crystal cell, and a viewer-side polarizer in this order. The polarizer obtained by the present invention can be used as a light source-side polarizer, a viewer-side polarizer, or both.

[0199] In this embodiment, in the eighth process, a liquid crystal display device is manufactured by laminating a polarizing plate (100) to a liquid crystal panel as a light source-side polarizing plate and a viewing-side polarizing plate, respectively.

[0200] FIG. 6 is a schematic cross-sectional view of a display device manufactured by the method of manufacturing a display device according to Embodiment 3 of the present invention. As shown in FIG. 6, the display device (400) has two substrates (410, 420), a liquid crystal layer (430) located between them, and polarizing plates (100, 100) each disposed on the outside of the two substrates (410, 420). The two polarizing plates (100) are polarizing plates (100) manufactured using the laminate (10) of Embodiment 1. As shown in FIG. 6, the two polarizing plates (100) are each laminated such that a resin layer (112) of the polarizing plate is disposed between the polarizer material film (111) of the polarizing plate and the liquid crystal layer (430).

[0201] According to the present embodiment, the resin layer can also be used as a protective film, and can be manufactured efficiently even with a thin thickness, and can also be provided with a display device equipped with a polarizing plate that prevents the occurrence of wrinkles and voids.

[0202] [Embodiment 4: Method for manufacturing a display device]

[0203] Hereinafter, a display device (500) according to Embodiment 4, which is equipped with a polarizing plate (120) manufactured in Embodiment 2, will be described with reference to FIG. 5 and FIG. 7.

[0204] The method for manufacturing a display device according to the present embodiment includes a process (the 8th process) of laminating a polarizing plate (120) shown in FIG. 5 onto a panel. In the present embodiment, an example of manufacturing an organic EL display device using an organic EL panel as the panel is described.

[0205] Typically, an organic EL display device comprises a substrate, a transparent electrode, a light-emitting layer, and a metal electrode layer in order from the light-emitting side, and a polarizing plate obtained by the manufacturing method of the present invention is disposed on the light-emitting side of the substrate.

[0206] Typically, an organic EL display device has two substrates, a light-emitting layer located between them, and a polarizing plate disposed on the outside of one of the two substrates. The organic EL display device can be manufactured by installing the polarizing plate of the present invention on an organic EL panel.

[0207] In this embodiment, in the eighth process, an organic EL display device is manufactured by laminating a polarizing plate (120) onto an organic EL panel.

[0208] FIG. 7 is a schematic cross-sectional view of a display device manufactured by the method of manufacturing a display device according to Embodiment 4 of the present invention. As shown in FIG. 7, the display device (500) has two substrates (510, 520), a light-emitting layer (530) located between them, and a polarizing plate (120) disposed on the outer side (lower side shown) of the lower substrate (510). The polarizing plate (120) is a polarizing plate (120) of Embodiment 2 manufactured using a laminate (10). As shown in FIG. 7, the polarizing plate (120) is laminated such that a resin layer (112) of the polarizing plate is disposed between the polarizer material film (111) of the polarizing plate and the light-emitting layer (530).

[0209] According to the present embodiment, the resin layer can also be used as a protective film, and can be manufactured efficiently even with a thin thickness, and can also be provided with a display device equipped with a polarizing plate that prevents the occurrence of wrinkles and voids.

[0210] [Other embodiments]

[0211] (1) In embodiment 2, an example was shown in which a protective film was laminated only on the side of the polarizer material film of the laminate, but a protective film may be laminated only on the side of the resin layer of the laminate, or a protective film may be laminated on both the side of the polarizer material film of the laminate and the side of the resin layer of the laminate.

[0212] (2) In embodiments 3 and 4, examples were shown where the panel is a liquid crystal panel and an organic EL panel, but the panel with the polarizing plate laminated thereon may be a micro LED panel.

[0213] (3) Embodiment 3 describes a method for manufacturing a liquid crystal display device in which two polarizing plates (100) described in Embodiment 1 are stacked, but is not limited thereto. Two polarizing plates (120) described in Embodiment 2 may be stacked, two types of polarizing plates may be stacked, or one polarizing plate may be stacked.

[0214] (4) In embodiment 4, a method for manufacturing an organic EL display device is shown by laminating the polarizing plate (120) of embodiment 2, but a polarizing plate (100) may be used instead of the polarizing plate (120).

[0215] Examples

[0216] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following, "parts" and "%" regarding the ratio of components represent parts by weight unless otherwise stated.

[0217] [Evaluation Method]

[0218] [Weight Average Molecular Weight (Mw) and Molecular Weight Distribution (Mw / Mn)]

[0219] The molecular weights of the block copolymer and block copolymer hydride were measured at 38°C as standard polystyrene equivalents by GPC using THF as the eluent. As the measuring device, the HLC8020GPC manufactured by Tosoh Co. was used.

[0220] [Hydrogenation Rate]

[0221] The hydrogenation rate of block copolymer hydrides is, 1 It was calculated by H-NMR spectroscopy or GPC analysis. The region with a hydrogenation rate of 99% or less is, 1 The H-NMR spectrum was measured and calculated, and the region exceeding 99% was calculated from the ratio of peak areas by the UV detector and the RI detector by GPC analysis.

[0222] [Measurement of MFR (Melt Flow Rate measured at 190℃ with a load of 2.16kg)]

[0223] The coating solution used in each example was applied to a separator film (manufactured by Mitsubishi Chemical, “MRV38”) using a die coater and dried to form a film containing polymer X with a thickness of 10 μm. The film containing polymer X was peeled off from the separator film to form a sample film. Using this sample film, the MFR was measured by the following method.

[0224] MFR was measured based on JIS K7210 using an extrusion-type plastometer (manufactured by Tateyama Kagaku Kogyo Co., Ltd., product name "Melt Indexer (L240)") as a measuring device under conditions of a temperature of 190°C and a load of 2.16 kg.

[0225] [Measurement of Tensile Modulus]

[0226] The tensile modulus was measured using a sample film prepared by the same method as the "sample film" described in the section on "Measurement of MFR".

[0227] The tensile modulus was measured according to JIS K7127 using a tensile testing machine (manufactured by Instron Japan Company Limited, product name “Electromechanical Universal Material Testing Machine (5564)”) by the following method.

[0228] A sample film was stamped into the shape of specimen type 1B as specified in JIS K7127, and the stress was measured when the specimen was deformed by pulling it in the long side direction. The stress measurement conditions were set as a temperature of 23°C, humidity of 60 ± 5%RH, a chuck distance of 115 mm, and a tensile speed of 50 mm / min. Stress measurements were performed five times. From the measured stress and the deformation data corresponding to that stress, four measurement data points were selected for every 0.2% of the deformation of the specimen within the range of 0.6% to 1.2% (i.e., measurement data when the deformation is 0.6%, 0.8%, 1.0%, and 1.2%), and the tensile modulus was calculated using the least squares method from the four measurement data points from the five measurements (a total of 20 points).

[0229] [Method for Measuring Phase Difference]

[0230] The in-plane phase difference Re1 and phase difference Re2 of the polarizer material film, and the in-plane phase difference of the resin layer in the polarizer were measured using a phase difference meter (manufactured by Opto Science Co., Ltd., Muller matrix polarimeter, trade name "Axo Scan"). During measurement, the measurement wavelength was set to 550 nm.

[0231] The measurement of the phase difference Re2 involved measuring the in-plane phase difference occurring in the resin layer obtained by uniaxially stretching the free end of the resin layer by 6.0 times at a predetermined temperature (50°C and 120°C). In this invention, if both the in-plane phase difference of the resin layer occurring when the laminate is uniaxially stretched by 6.0 times at a temperature of 50°C and the in-plane phase difference of the resin layer occurring when the laminate is uniaxially stretched by 6.0 times at a temperature of 120°C are within the range of 0 nm or more and 20 nm or less, it was determined that the in-plane phase difference Re2 of the resin layer occurring when the laminate is uniaxially stretched by 6.0 times at a temperature of 50°C to 120°C is 0 nm or more and 20 nm or less.

[0232] [Method for measuring thickness]

[0233] The thickness of each film (polarizer material film and resin layer) included in the laminate and the thickness of each film included in the polarizer were measured five times using a thickness gauge (manufactured by Mitutoyo Corporation, product name “ABS Digimatic Thickness Gauge (547-401)”) and the average value was taken as the thickness of each film.

[0234] [Evaluation of the surface condition of the polarizer]

[0235] The surface of each polarizer was observed by visual inspection, and the number of wrinkles and voids per 10 cm square was measured. Measurements were taken at five locations on the polarizer, the average value was calculated, and the evaluation was performed according to the following evaluation criteria.

[0236] A: No wrinkles or voids are observed.

[0237] B: The number of wrinkles is 1 or more and 3 or less, or the number of voids is 1 or more and less than 10.

[0238] C: The number of wrinkles is 4 or more, or the number of voids is 10 or more.

[0239] [Evaluation of Closeness]

[0240] In the process up to the second stretching treatment in the manufacture of the polarizing plate of each example, A was designated as the case where no delamination occurred between the polarizer material film and the resin layer, B was designated as the case where delamination was seen in some parts, and C was designated as the case where it was completely delaminated.

[0241] [Evaluation of Drying Processability]

[0242] In the drying process at 70°C for 5 minutes during the manufacture of the polarizing plates of each example, the one in which no cracks occurred in the polarizer was designated as A, and the one in which cracks occurred was designated as C.

[0243] [Black Color Shift]

[0244] A liquid crystal display panel was removed from a liquid crystal display device (manufactured by LG Electronics Japan, product name “IPS Panel Monitor (23MP47)”), and a polarizing plate positioned on the viewing side was peeled off. Then, the polarizing plates prepared in the examples and comparative examples were laminated so that the resin layer was on the panel side. Additionally, a polarizer unit without a protective film was laminated next to the polarizing plate prepared in the examples and comparative examples, and the liquid crystal display device was reassembled. The absorption axis of the polarizing plate prepared in the examples and comparative examples and the polarizer unit without a protective film was laminated so that it was in the same direction as the absorption axis of the polarizing plate before peeling.

[0245] When the direction of the absorption axis of the polarizer placed on the viewing side was set to an azimuth angle of 0° and the vertical direction of the panel was set to a deviation angle of 0°, the panel was set to a black display state (i.e., a state where black is displayed on the entire display screen of the panel), and visual inspection was performed at an azimuth angle of 45° and a deviation angle of 45°. It was determined that the color change was the same as in the case of a polarizer without a protective film as A, the color change was slight as B, and the change was large as C.

[0246] [Example 1]

[0247] (1-1) Preparation of polarizer material film

[0248] As a base film, an unoriented polyvinyl alcohol film (average degree of polymerization about 2400, degree of saponification 99.9 mol%, thickness 20 μm, hereinafter also referred to as “PVA20”) was used.

[0249] A raw film was dry-stretched using a longitudinal uniaxial stretcher at a stretching temperature of 130°C in the longitudinal direction at a stretching ratio of 1.5 times (X = 1.5) to obtain a polarizer material film. The thickness T1 of the polarizer material film was 16 μm, and Re1 was 320 nm.

[0250] (1-2) Fabrication of Polymer X

[0251] Referring to the manufacturing example described in Japanese Patent Publication No. 2002-105151, 25 parts of styrene monomer were polymerized in the first step, then 30 parts of styrene monomer and 25 parts of isoprene monomer were polymerized in the second step, and then 20 parts of styrene monomer were polymerized in the third step to obtain a block copolymer [D1], and then the block copolymer was hydrogenated to synthesize a block copolymer hydride [E1]. The Mw of the block copolymer hydride [E1] was 84,500, the Mw / Mn was 1.20, and the hydrogenation rate of the main chain and aromatic ring was approximately 100%.

[0252] 100 parts of block copolymer hydride [E1] and 0.1 parts of pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by Matsubara Sangyo Co., Ltd., product name "Songnox 1010") as an antioxidant were melt-kneaded and blended, then formed into pellets to obtain polymer X for molding.

[0253] (1-3) Manufacture of laminates

[0254] After dissolving the polymer X prepared in (1-2) in cyclohexane, 40 parts by weight of polyisobutene ("Nissei Polybutene HV-300" manufactured by JX Nikko Nisseki Energy, number average molecular weight 1,400) and 0.1 parts by weight of an organosilicon compound (3-aminopropyltriethoxysilane, KBM903 manufactured by Shin-Etsu Chemical Co., Ltd.) were added to 100 parts by weight of polymer X to prepare a coating solution A (resin composition A) for film formation.

[0255] The obtained coating solution A for film formation was applied and dried on one side of the polarizer material film prepared in (1-1) using a die coater. By doing so, a long laminate consisting of a polarizer material film and a resin layer (width 600 mm, thickness 10 μm) containing polymer X was obtained.

[0256] In the obtained laminate, the thickness of the resin layer, the thickness T1 of the polarizer material film, and the in-plane phase difference Re1 and phase difference Re2 (temperature conditions 50°C, 120°C) were measured. In addition, the MFR and tensile modulus of the resin constituting the resin layer were measured by the method described in the evaluation method. The results are shown in Table 1.

[0257] (1-4) Manufacturing of polarizing plates

[0258] The laminate manufactured in (1-3) was continuously conveyed in the longitudinal direction through a guide roll, and the following operations were performed.

[0259] The above laminate was subjected to a swelling treatment by immersion in water, a dyeing treatment by immersion in a dyeing solution containing iodine and potassium iodide, and a first stretching treatment by stretching the laminate after the dyeing treatment. Subsequently, the laminate after the first stretching treatment was subjected to a second stretching treatment by stretching in a bath containing boric acid and potassium iodide. The total stretching ratio, expressed as the product of the stretching ratio in the first stretching treatment and the stretching ratio in the second stretching treatment, was set to 4.0 times (Z = 4.0). The stretching temperature was set to 57°C. The laminate after the second stretching treatment was dried in a dryer at 70°C for 5 minutes (drying process) to obtain a polarizing plate.

[0260] Adhesion was evaluated during the process up to the second stretching treatment, and drying processability was evaluated during the drying process. For the obtained polarizing plate, surface condition and black color shift were evaluated. The evaluation results are shown in Table 1.

[0261] In addition, the thickness of the resin layer, the phase difference, and the thickness of the polarizer material film in the obtained polarizer were measured, and the measurement results are shown in Table 1.

[0262] [Example 2]

[0263] A laminate and a polarizer were manufactured by performing the same operations as in Example 1, except that the stretching ratio of the base film was 5.5 times (X = 5.5) and the stretching ratio of the laminate was 1.2 times (Z = 1.2), and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0264] [Example 3]

[0265] Except for setting the stretching ratio of the base film to 2.0 times (X = 2.0), adjusting the amount of coating when applying and drying the coating solution A for film formation in (1-3) of Example 1 to form a resin layer with a thickness of 5 μm (width is the same as in Example 1), and setting the stretching ratio of the laminate to 3.0 times (Z = 3.0), the same operations as in Example 1 were performed to manufacture a laminate and a polarizing plate, and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0266] [Example 4]

[0267] Except for setting the stretching ratio of the base film to 3.0 times (X = 3.0) and the stretching ratio of the laminate to 2.0 times (Z = 2.0), the same operation as in Example 1 was performed to manufacture the laminate and the polarizer, and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0268] [Example 5]

[0269] Except for setting the stretching ratio of the base film to 3.0 times (X = 3.0), using coating solution B instead of coating solution A for film formation, and setting the stretching ratio of the laminate to 2.0 times (Z = 2.0), the same operations as in Example 1 were performed to manufacture a laminate and a polarizer, and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0270] Coating solution B for film formation was prepared by the following method.

[0271] After dissolving the polymer X prepared in (1-2) of Example 1 in cyclohexane, 0.1 parts by weight of an organosilicon compound (3-aminopropyltriethoxysilane, KBM903, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by weight of polymer X to prepare a coating solution B (resin composition B) for film formation.

[0272] [Example 6]

[0273] Except for setting the stretching ratio of the base film to 3.0 times (X = 3.0), using coating solution C instead of coating solution A for film formation, and setting the stretching ratio of the laminate to 2.0 times (Z = 2.0), the same operations as in Example 1 were performed to manufacture the laminate and polarizer, and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[0274] Coating solution C for film formation was prepared by the following method.

[0275] After dissolving the polymer X prepared in (1-2) of Example 1 in cyclohexane, 40 parts by weight of polyisobutene ("Nissei Polybutene HV-300" manufactured by JX Nikko Nisseki Energy, number average molecular weight 1,400) and 0.1 parts by weight of an organic titanium compound (tetraisopropyl titanate, Orgatics TA-8, manufactured by Matsumoto Fine Chemical Co.) were added to 100 parts by weight of polymer X to produce a coating solution C (resin composition C) for film formation.

[0276] [Example 7]

[0277] Except for setting the stretching ratio of the base film to 2.0 times (X = 2.0), using coating solution D instead of coating solution A for film formation, and setting the stretching ratio of the laminate to 3.0 times (Z = 3.0), the same operations as in Example 1 were performed to manufacture the laminate and polarizer, and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[0278] Coating solution D for film formation was prepared by the following method.

[0279] After dissolving the polymer X prepared in (1-2) of Example 1 in cyclohexane, 40 parts by weight of polyisobutene ("Nissei Polybutene HV-300" manufactured by JX Nikko Nisseki Energy, number average molecular weight 1,400) and 0.1 parts by weight of an organic zirconium compound (normal propyl zirconate, Orgatics ZA-45, manufactured by Matsumoto Fine Chemical Co.) were added to 100 parts by weight of polymer X to produce a coating solution D (resin composition D) for film formation.

[0280] [Example 8]

[0281] A laminate and a polarizer were manufactured by performing the same operations as in Example 1, except that an unoriented polyvinyl alcohol film with a thickness of 45 μm (average degree of polymerization of about 2400, degree of saponification of 99.9 mol%, hereinafter also referred to as "PVA45") with a thickness of 45 μm was used as the base film instead of PVA20, the stretching ratio of the base film was set to 2.0 times (X = 2.0), and the stretching ratio of the laminate was set to 3.0 times (Z = 3.0), and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[0282] [Example 9]

[0283] A laminate and a polarizer were manufactured by performing the same operations as in Example 1, except that PVA45 was used instead of PVA20 as the base film, the stretching ratio of the base film was set to 3.0 times (X = 3.0), and the stretching ratio of the laminate was set to 2.0 times (Z = 2.0), and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[0284] [Example 10]

[0285] A laminate and a polarizer were manufactured by performing the same operations as in Example 1, except that an unoriented polyvinyl alcohol film with a thickness of 60 μm (average degree of polymerization of about 2400, degree of saponification of 99.9 mol%, hereinafter also referred to as "PVA60") was used as the base film instead of PVA20, the stretching ratio of the base film was set to 2.0 times (X = 2.0), and the stretching ratio of the laminate was set to 3.0 times (Z = 3.0), and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

[0286] [Example 11]

[0287] Except for setting the stretching ratio of the base film to 3.0 times (X = 3.0), using coating solution E instead of coating solution A for film formation, and setting the stretching ratio Z of the laminate to 2.0, the same operations as in Example 1 were performed to manufacture a laminate and a polarizer, and the same evaluation as in Example 1 was performed. The results are shown in Table 3.

[0288] The coating solution E for film formation was prepared by the following method.

[0289] After dissolving the polymer X prepared in (1-2) of Example 1 in cyclohexane, 40 parts by weight of polyisobutene ("Nissei Polybutene HV-300" manufactured by JX Nikko Nisseki Energy Co., Ltd., number average molecular weight 1,400) was added to 100 parts by weight of polymer X to produce a coating solution E (resin composition E) for film formation.

[0290] [Comparative Example 1]

[0291] In Example 1 (1-4), the same operation as in Example 1 (1-4) was performed except that PVA20 (unoriented polyvinyl alcohol resin film) was used instead of the laminate manufactured in (1-3). As a result, melting occurred frequently during the first stretching treatment and the second stretching treatment, and breaking occurred frequently during the drying process, making it impossible to evaluate the surface condition, adhesion, and black color shift.

[0292] [Comparative Example 2]

[0293] (C2-1) Preparation of polarizer material film

[0294] PVA20 was used as the base film, and a polarizer material film was obtained by dry stretching using a uniaxial stretching machine at a stretching temperature of 130°C in the longitudinal direction at a stretching ratio of 2.0 (X = 2.0). The thickness T1 of the polarizer material film was 14 μm, and Re1 was 350 nm.

[0295] (C2-2) Manufacture of laminates

[0296] By applying the coating solution A prepared in (1-3) of Example 1 to a separator film (manufactured by Mitsubishi Chemical, “MRV38”) using a die coater and drying it, a long film (resin film) containing polymer X with a width of 650 mm, a length of 500 m, and a thickness of 10 μm was obtained.

[0297] An adhesive was obtained by mixing 100 parts by weight of water, 3 parts by weight of a polyvinyl alcohol-based adhesive ("Z-200" manufactured by Nippon Synthetic Chemical Co., Ltd.), and 0.3 parts by weight of a crosslinking agent ("SPM-01" manufactured by Nippon Synthetic Chemical Co., Ltd.). This adhesive was applied to one side of the resin film, and the polarizer material film prepared in (C2-1) was laminated. In this state, the adhesive was heated and dried at 70°C for 5 minutes to obtain a laminate. A polarizing plate was obtained by performing the same operation as in (1-4) of Example 1 on the obtained laminate. The obtained laminate and polarizing plate were evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0298] In the table, “Re2(50℃)” refers to the in-plane phase difference of the resin layer that occurs when the laminate is uniaxially stretched at the free end by 6.0 times under a temperature condition of 50℃, and “Re2(120℃)” refers to the in-plane phase difference of the resin layer that occurs when the laminate is uniaxially stretched at the free end by 6.0 times under a temperature condition of 120℃.

[0299] In the table, "Re1" refers to the in-plane phase difference of the polarizer material film in the laminate.

[0300] In the table, “direct coating” indicates that the resin layer is formed by directly applying a coating solution (resin composition) for film formation to the polarizer material film, and “lamination” indicates that the resin film is laminated to the polarizer material film through an adhesive.

[0301] In the table, "polarizer" refers to a polarizer material film in a polarizer.

[0302]

[0303]

[0304]

[0305] From the results of Tables 1 to 3, it can be seen that according to the present invention, the phase difference expressed in the resin layer after the process of stretching the laminate can be reduced, and a polarizing plate with excellent adhesion, drying processability, and optical properties can be obtained. In addition, it can be seen that according to the present invention, the occurrence of wrinkles and voids can be prevented. Accordingly, it can be seen that the resin layer can be used as a protective film, and can be manufactured efficiently even with a thin thickness, and a laminate and a method for manufacturing the same that prevent the occurrence of wrinkles and voids, a polarizing plate using the said laminate and a method for manufacturing the same, and a method for manufacturing a display device can be provided. Explanation of the symbols

[0306] 1… Fabric film 10… laminate 11… Polarizer material film 12… resin layer 100, 120… polarizing plate 111… Polarizer material film 112… Suji layer 115… protective film 200… manufacturing device 201… Unwinding device 202… Coating device 203… Winding device 204… stretching device 205… Activation Processor 206… drying device 300… manufacturing device 301, 307… Unwinding device 302 ~ 305… Processing unit 306… drying device 308… Joining device 310… winding device 400… display device (liquid crystal display) 410, 420… circuit board 430… liquid crystal layer 500… display device (organic EL display device) 510, 520… circuit board 530… emissive layer

Claims

Claim 1 A laminate having a polarizer material film and a resin layer formed directly on the polarizer material film, wherein the in-plane phase difference Re1 of the polarizer material film is greater than 50 nm, the thickness T1 of the polarizer material film is 45 μm or less, the in-plane phase difference Re2 of the stretched resin layer is 0 nm or more and 20 nm or less, the stretched resin layer is a stretched product of the resin layer in the stretched laminate, and the stretched laminate is a stretched product obtained by free-end uniaxial stretching of the laminate by 6.0 times under temperature conditions of 50°C to 120°C. Claim 2 In claim 1, the laminate is a polarizer material film which is a film obtained by stretching at a stretching ratio of X times. Claim 3 In claim 2, X is a laminate satisfying 1.5 ≤ X ≤ 5.

5. Claim 4 In claim 1, the laminate in which the polarizer material film is a polyvinyl alcohol resin film. Claim 5 In claim 4, the laminate having a transmittance of 50% or more of light at a wavelength of 550 nm of the polyvinyl alcohol resin film. Claim 6 A laminate according to claim 1, wherein the resin layer is made of a cycloolefin-based resin. Claim 7 A laminate according to claim 6, wherein the cycloolefin resin comprises a cycloolefin polymer, and the cycloolefin polymer is a block copolymer hydride obtained by hydrogenating a block copolymer [D] comprising a polymer block [A] containing more than 60 mass% of repeating units [I] derived from an aromatic vinyl compound, a polymer block [B] containing more than 60 mass% of repeating units [I] derived from an aromatic vinyl compound and repeating units [II] derived from a chain-type conjugated diene compound as a sum, or a polymer block [C] containing more than 60 mass% of repeating units [II] derived from a chain-type conjugated diene compound. Claim 8 A laminate according to claim 1, wherein the resin layer is a layer made of resin, and the resin has a melt flow rate of 1 g / 10 min or more and a tensile modulus E of 50 MPa or more and 1200 MPa or less, and the melt flow rate is a value measured at 190°C and a load of 2.16 kg. Claim 9 In claim 1, the resin layer comprises a laminate containing a plasticizer, a softener, or both. Claim 10 A laminate according to claim 9, wherein the plasticizer, the softener, or both are one or more selected from ester-based plasticizers and aliphatic hydrocarbon polymers. Claim 11 In claim 1, the resin layer is a laminate containing an organometallic compound. Claim 12 A polarizing plate that is a uniaxially stretched laminate described in any one of claims 1 to 11. Claim 13 A method for manufacturing a laminate comprising, in this order, a first process of stretching a base film containing a polarizer material to obtain a polarizer material film, a second process of applying a resin to one surface of the polarizer material film to form a coating layer, and a third process of drying the coating layer to obtain a resin layer, wherein the phase difference Re2 in the in-plane direction of the stretched resin layer is 0 nm or more and 20 nm or less, the stretched resin layer is a stretched product of the resin layer in the stretched laminate, and the stretched laminate is a stretched product obtained by free-end uniaxial stretching of the laminate by 6.0 times under temperature conditions of 50°C to 120°C. Claim 14 A method for manufacturing a laminate according to claim 13, wherein in the first process above, the stretching ratio of the stretching is X times, and X satisfies 1.5 ≤ X ≤ 5.

5. Claim 15 A method for manufacturing a laminate according to claim 13, comprising a fourth process of activating the surface of the polarizer material film prior to the second process. Claim 16 A method for manufacturing a polarizing plate, comprising: a process of preparing a laminate as described in any one of claims 1 to 11 or manufacturing a laminate by a method for manufacturing a laminate as described in any one of claims 13 to 15; a fifth process of dyeing the laminate with a dichroic pigment; and a sixth process of uniaxially stretching the laminate. Claim 17 A method for manufacturing a polarizing plate according to claim 16, wherein in the 6th process above, the stretching ratio is Z times, and Z satisfies 1.2 ≤ Z ≤ 5.

0. Claim 18 A method for manufacturing a polarizing plate according to claim 16, wherein X and Z satisfy 5.1 ≤ X * Z ≤ 9.

0. Claim 19 A method for manufacturing a polarizing plate according to claim 16, comprising a seventh step of laminating a protective film to one or both of the polarizer material film side surface and the resin layer side surface of the laminate after passing through the fifth step, the sixth step, or both thereof. Claim 20 A method for manufacturing a display device comprising a process of manufacturing a polarizing plate by the method for manufacturing a polarizing plate described in claim 16, and an 8th process of laminating the polarizing plate onto a panel, wherein the panel is a panel selected from a liquid crystal panel, an organic electroluminescence panel, and a micro LED panel. Claim 21 delete

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