Laminate and method for manufacturing the same, and method for manufacturing a polarizing film

Abstract

To provide a laminate which has a base material and a resin layer, and is excellent in transferability of the resin layer.SOLUTION: A laminate includes a base material, and a resin layer which is composed of a thermoplastic resin containing a polymer and a solvent and is formed on the base material, wherein a percentage content of the solvent in the resin layer is 0.01 wt.% to 10 wt.%, the base material contains the same solvent as the solvent contained in the resin layer, and a peel force between the base material and the resin layer is larger than 0.1 N / 25 mm and smaller than 2.5 N / 25 mm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a laminate, a method for manufacturing the same, and a method for manufacturing a polarizing film. [Background technology]

[0002] Generally, a polarizing film comprises a polarizer layer and a resin layer provided on the surface of the polarizer layer (Patent Document 1). The resin layer can function as a protective layer to protect the polarizer layer. Such a protective layer may be manufactured, for example, by coating a coating liquid containing the material for the resin layer onto a substrate and drying it (Patent Document 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2019 / 087806 [Patent Document 2] Japanese Patent Publication No. 2014-130298 [Overview of the project] [Problems that the invention aims to solve]

[0004] When manufacturing a polarizing film using a resin layer formed on a substrate, the resin layer is usually transferred to the polarizer layer. Specifically, the polarizer layer and the resin layer are bonded together, and the substrate is peeled off to obtain the polarizing film. Therefore, it is necessary for the substrate and the resin layer to be easily peeled off. However, if the substrate and the resin layer are excessively easy to peel off, delamination may occur between the substrate and the resin layer at unintended times. Such unintended delamination can make it difficult to stably transfer the resin layer to the polarizer layer.

[0005] The present invention was devised in view of the above-mentioned problems, and aims to provide a laminate comprising a base material and a resin layer, having excellent transferability of the resin layer, and a method for manufacturing the same; and a method for manufacturing a polarizing film using the above-mentioned laminate. [Means for solving the problem]

[0006] The inventors diligently studied to solve the aforementioned problems. As a result, the inventors found that a laminate comprising a substrate and a resin layer formed on the substrate, wherein the substrate and the resin layer contain the same solvent, the solvent content in the resin layer is within a specific range, and the peeling force between the substrate and the resin layer is within a specific range can solve the aforementioned problems, and thus completed the present invention. In other words, the present invention includes the following:

[0007] [1] comprising a base material and a resin layer formed on the base material with a thermoplastic resin containing a polymer and a solvent, The solvent content in the resin layer is 0.01% by weight to 10% by weight. The substrate contains the same solvent as the resin layer, A laminate in which the peel force between the substrate and the resin layer is greater than 0.1 N / 25 mm and less than 2.5 N / 25 mm. [2] The laminate according to [1], wherein the content of the solvent in the substrate is 0.05% by weight or more and 1.5% by weight or less. [3] The laminate according to [1] or [2], wherein the dimensional change rate in the width direction of the laminate when heated at 120°C for 15 minutes is -0.4% or more and 1.3% or less. [4] The water vapor transmission rate per 100 μm of thickness of the thermoplastic resin is 4 g / (m²). 2 A laminate described in any one of the following three items (1) to (3), which is less than or equal to (day). [5] The in-plane retardation of the resin layer at a measurement wavelength of 550 nm is 5 nm or less. The laminate according to any one of [1] to [4], wherein the retardation in the thickness direction of the resin layer at a measurement wavelength of 550 nm is -5 nm or more and 5 nm or less. [6] The laminate according to any one of [1] to [5], wherein the polymer contains an alicyclic structure. [7] The laminate according to any one of [1] to [6], wherein the thickness of the resin layer is 9 μm or less. [8] The laminate according to any one of [1] to [7], wherein the resin layer contains 2% to 40% by weight of an ultraviolet absorber. [9] The laminate according to [8], wherein the ultraviolet absorber can be dissolved in a hydrocarbon solvent or a cyclic ether solvent at a concentration of 2% by weight or more.

[10] The substrate comprises one or more layers, Of the layers provided by the substrate, the layer closest to the resin layer contains the first resin. The laminate according to any one of [1] to [9], wherein the content of the solvent in the first resin is 0.05% by weight or more and 1.5% by weight or less.

[11] A method for manufacturing a laminate according to any one of items [1] to

[10] , The process involves coating the substrate with a resin solution containing the polymer and the solvent, A method for manufacturing a laminate, comprising the step of drying a resin liquid coated onto the substrate.

[12] The method for manufacturing a laminate according to

[11] , wherein the substrate to which the resin liquid is coated has a dimensional change rate in the width direction of -0.4% or more and 1.3% or less when heated at 120°C for 15 minutes.

[13] A step of bonding the polarizer layer to the resin layer of the laminate described in any one of [1] to

[10] , A method for manufacturing a polarizing film, comprising the step of peeling off the substrate from the laminate.

[14] The method for manufacturing a polarizing film according to

[13] , wherein the thickness of the polarizer layer is 19 μm or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a laminate comprising a base material and a resin layer, having excellent transferability of the resin layer, and a method for manufacturing the same; and a method for manufacturing a polarizing film using the laminate. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments and examples of the present invention will be described in detail. However, the present invention is not limited to the embodiments and examples shown below, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and its equivalent scope.

[0010] In the following description, "long" refers to a shape having a length that is usually at least 5 times the width, preferably 10 times or more the length, and specifically, a shape having a length such that it can be wound into a roll for storage or transportation. The upper limit of the ratio of the length to the width is not particularly limited, but can be, for example, 100,000 times or less.

[0011] In the following description, unless otherwise specified, an adhesive and a tackifier are distinguished by the shear storage modulus. Specifically, unless otherwise specified, an adhesive refers to a material having a shear storage modulus at 23°C of 1 MPa to 500 MPa after energy ray irradiation or heat treatment. Also, unless otherwise specified, a tackifier refers to a material having a shear storage modulus at 23°C of less than 1 MPa.

[0012] In the following description, unless otherwise specified, the in-plane retardation Re of a certain layer is a value represented by Re = (nx - ny) × d. Also, the retardation Rth in the thickness direction of a certain layer is a value represented by Rth = [((nx + ny) / 2) - nz] × d. Here, nx represents the refractive index in the direction perpendicular to the thickness direction (in-plane direction) of the layer and giving the maximum refractive index. ny represents the refractive index in the in-plane direction of the layer and perpendicular to the direction of nx. nz represents the refractive index in the thickness direction of the layer. d represents the thickness of the layer. Unless otherwise specified, the measurement wavelength is 550 nm.

[0013] In the following description, unless otherwise specified, (meth)acrylic resin includes acrylic resin, methacrylic resin, and combinations thereof. Also, (meth)acrylic acid includes acrylic acid, methacrylic acid, and combinations thereof.

[0014] In the following description, unless otherwise specified, "plate," "layer," and "film" may refer to rigid members, or they may refer to flexible members such as a resin film.

[0015] In the following explanation, "content rate" for items containing two or more ingredients refers to the total content rate of those ingredients unless otherwise specified.

[0016] [1. Overview of the Laminate] A laminate according to one embodiment of the present invention comprises a substrate and a resin layer formed on the substrate using a thermoplastic resin containing a polymer and a solvent. In the following description, the "substrate" and "resin layer" of the laminate according to this embodiment may be referred to as the "temporary substrate" and the "specific resin layer." In the following description, the laminate according to this embodiment, comprising the temporary substrate and the specific resin layer, may be referred to as the "transfer-type laminate."

[0017] The solvent content in the specific resin layer is within a specific range. Furthermore, the temporary substrate contains the same solvent as the specific resin layer. In other words, the temporary substrate and the specific resin layer contain a common solvent. Hereafter, the solvent contained in both the temporary substrate and the specific resin layer may be referred to as the "common solvent." The temporary substrate and the specific resin layer also possess a specific range of peeling force. Here, "peeling force" between the temporary substrate and the specific resin layer refers to the force required to separate the temporary substrate from the specific resin layer. Therefore, a greater peeling force indicates a higher adhesion between the temporary substrate and the specific resin layer.

[0018] A transfer-type laminate is typically used to provide a specific resin layer on a member (e.g., a polarizer layer) by a method that includes transferring the specific resin layer from a temporary substrate to a member. Specifically, the specific resin layer can be provided on the member by bonding the member and the specific resin layer of the transfer-type laminate together and then peeling off the temporary substrate. Here, "transferring" a layer means moving that layer from one member to another member, and includes both peeling the layer off one member and then bonding it to the other member, and bonding the layer on one member to the other member and then removing the other member. Therefore, when using a transfer-type laminate, the specific resin layer may be provided on the member by bonding the member and the specific resin layer of the transfer-type laminate together and then peeling off the temporary substrate. Alternatively, when using a transfer-type laminate, the specific resin layer may be provided on the member by peeling off the temporary substrate from the transfer-type laminate and then bonding the specific resin layer to the member. In either case, the transfer-type laminate according to this embodiment exhibits excellent transferability of the specific resin layer, enabling smooth transfer.

[0019] In detail, this transfer-type laminate has excellent handling properties because it can suppress unintended delamination between the temporary substrate and the specific resin layer, allowing for smooth bonding between the specific resin layer and the component. Furthermore, because the temporary substrate can be easily peeled off this transfer-type laminate, deformation and damage to the specific resin layer due to the peeling of the temporary substrate can be suppressed. Therefore, the transfer of the specific resin layer from the temporary substrate to another component can be performed smoothly, resulting in excellent transferability.

[0020] [2. Temporary base material] The temporary substrate is a component capable of supporting a specific resin layer, and can be, for example, a film, sheet, or plate made of an appropriate material. From the viewpoint of improving the handling properties of the transfer-type laminate, the temporary substrate is preferably a film.

[0021] The temporary substrate contains the same common solvent as the specific resin layer. This common solvent may be one type or two or more types. When the temporary substrate contains the same common solvent as the specific resin layer, the peeling force between the temporary substrate and the specific resin layer can be increased. From the viewpoint of adjusting the peeling force between the temporary substrate and the specific resin layer to an appropriate range, the content of the common solvent in the temporary substrate, relative to 100% by weight of the temporary substrate, is preferably within a specific range. This specific range of the common solvent content is preferably 0.05% by weight or more, more preferably 0.08% by weight or more, particularly preferably 0.10% by weight or more, preferably 1.5% by weight or less, more preferably 1.2% by weight or less, and particularly preferably 1.0% by weight or less.

[0022] The content of the common solvent in the temporary substrate can be measured using a gas chromatograph-mass spectrometer. The specific measurement method can be the one described in the examples.

[0023] The content of the common solvent in the temporary substrate can be adjusted, for example, by the type of common solvent, the type and amount of polymer contained in the temporary substrate, and the drying temperature and drying time of the resin liquid during the formation of a specific resin layer.

[0024] Temporary substrates are typically formed from resin. Therefore, temporary substrates usually contain resin, and preferably contain only resin. Thermoplastic resins are preferred as the resin contained in the temporary substrate. Hereinafter, in order to clarify the distinction between the resin contained in the temporary substrate and the thermoplastic resin contained in the specific resin layer, the aforementioned resin contained in the temporary substrate may be referred to as the "first resin," and the thermoplastic resin contained in the specific resin layer may be referred to as the "second resin."

[0025] The first resin contained in the temporary substrate usually contains a polymer, preferably a thermoplastic polymer. In the following description, the polymer contained in the first resin may be referred to as the "first polymer." Furthermore, since the temporary substrate contains a common solvent, the first resin contained in the temporary substrate may contain the common solvent in combination with the first polymer. The specific type of first polymer contained in the first resin is preferably selected according to its affinity for the common solvent. More specifically, it is preferable that the first polymer has a high affinity for the common solvent to such an extent that the common solvent can penetrate the temporary substrate. Since the common solvent can easily penetrate the first resin containing such a highly affinity first polymer, the temporary substrate can contain the same common solvent as the common solvent contained in a specific resin layer. The temporary substrate may, for example, consist only of a layer containing such a highly affinity first polymer. Alternatively, the temporary substrate may include, for example, a support layer formed of a material such as resin, and a layer containing the first polymer formed on this support layer.

[0026] Examples of the first polymer include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate; acrylic polymers such as polymethyl methacrylate; cellulose polymers such as triacetylcellulose; and polycarbonates, with polyolefins being preferred among them. The first polymer may be used alone or in combination of two or more types.

[0027] The content of the first polymer in the temporary substrate is preferably within a specific range relative to 100% by weight of the temporary substrate. This specific range of the first polymer content is preferably 50% by weight or more, more preferably 70% by weight or more, particularly preferably 90% by weight or more, preferably 99.95% by weight or less, and more preferably 99.90% by weight or less. Furthermore, the content of the first polymer in the first resin is preferably within the same specific range as the content of the first polymer in the temporary substrate relative to 100% by weight of the temporary substrate. When the content of the first polymer is above the lower limit, the rigidity of the temporary substrate can be increased, improving the handling properties of the transfer-type laminate. Furthermore, when the content of the first polymer is below the upper limit, the adhesion between the temporary substrate and the specific resin layer can be effectively increased, thereby effectively increasing the peeling force between the temporary substrate and the specific resin layer.

[0028] As described above, since the temporary substrate contains the same common solvent as the specific resin layer, the first resin contained in the temporary substrate may contain the common solvent in combination with the first polymer. The content of the common solvent in the first resin, relative to 100% by weight of the total amount of the first resin, is preferably within the same specific range as the content of the common solvent in the temporary substrate relative to 100% by weight of the temporary substrate as described above. The content of the common solvent in the first resin can be measured by gas chromatography-mass spectrometry.

[0029] The first resin may contain any additional components in combination with the first polymer and common solvent. Examples of optional components include stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers; resin modifiers such as lubricants and plasticizers; and antistatic agents. Any one component may be used alone, or two or more may be used in combination.

[0030] The temporary substrate may have a single-layer structure comprising only one layer having the same composition, or it may have a multi-layer structure comprising multiple layers having different compositions. If the temporary substrate has a multi-layer structure, it is preferable that the layer closest to the specific resin layer contains the first resin described above. In one example, the temporary substrate may have a single-layer structure containing only the first resin.

[0031] The temporary substrate preferably exhibits a dimensional change rate within a specific range when subjected to a heating test in which it is heated at 120°C for 15 minutes. Specifically, the dimensional change rate of the temporary substrate when subjected to the above heating test is preferably -0.4% or more, more preferably -0.3% or more, particularly preferably -0.2% or more, preferably 1.3% or less, more preferably 0.8% or less, and particularly preferably 0.5% or less. The above dimensional change rate represents the dimensional change rate in the width direction of the temporary substrate. Furthermore, a positive value of this dimensional change rate indicates that the temporary substrate expands, and a negative value indicates that the temporary substrate contracts. It is preferable that the temporary substrate has the above-mentioned dimensional change rate within a specific range before the manufacture of the transfer-type laminate, and it is more preferable that it has the above-mentioned dimensional change rate within a specific range both before and after the manufacture of the transfer-type laminate. When the temporary substrate has such a dimensional change rate within a specific range, the peeling force between the temporary substrate and the specific resin layer can be adjusted to a particularly appropriate range. In addition, it is usually possible to suppress the occurrence of deformations such as troughs and folds in the transfer-type laminate. Here, the "trough" in the transfer-type laminate refers to the wavy shape of the transfer-type laminate.

[0032] The dimensional change rate of the temporary substrate can be measured by the following method. Cut the temporary substrate into a 150mm square and draw a 100mm square in the center. Two sides of this square are drawn parallel to the width direction of the temporary substrate (corresponding to the width direction of a long temporary substrate). Using a universal projector (Nikon "PROFILE PROJECTOR V-12B"), measure the distance between the vertices of the drawn square in the width direction of the temporary substrate to obtain the spacing before the heating test. Then, perform a heating test by heating the temporary substrate at 120°C for 15 minutes. After the temporary substrate has cooled to room temperature, measure the distance between the vertices of the drawn square again in the width direction of the temporary substrate to obtain the spacing after the heating test. Subtract the spacing before the heating test from the spacing after the heating test to find the dimensional change of the temporary substrate due to the heating test. Divide this dimensional change by the spacing before the heating test to calculate the dimensional change rate due to the heating test.

[0033] The temporary base material may have a long shape or a single-leaf shape.

[0034] There are no particular restrictions on the thickness of the temporary substrate. Specifically, the thickness of the temporary substrate is preferably 25 μm or more, more preferably 30 μm or more, particularly preferably 38 μm or more, preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 70 μm or less.

[0035] The temporary substrate described above can be manufactured, for example, by a method that includes forming a first resin into a film. Examples of molding methods include melt molding and solution casting. Alternatively, the film of the first resin thus obtained may be used as the temporary substrate, or the film may be subjected to a stretching treatment. Examples of stretching treatments include uniaxial stretching, in which stretching is performed in only one direction, and biaxial stretching, in which stretching is performed in two different directions, with biaxial stretching being preferred. Furthermore, it is preferable to perform the stretching treatment slowly over a long period of time. When stretching is performed over a long period of time, a large thermal history can be given to the temporary substrate, and as a result, the dimensional change rate of the temporary substrate can be easily kept within the specific range described above. Furthermore, for example, the temporary substrate may be manufactured by a method that includes forming a layer of the first resin on a support layer.

[0036] Furthermore, the temporary base material may be a commercially available product purchased from the market. Examples of commercially available temporary base materials having the above-mentioned desirable dimensional change rate include Toray Industries' biaxially oriented polypropylene film "New Type Trefan BO40-2500" and Unitika's polyethylene terephthalate films "Unipeel TR1", "Unipeel TR5", and "Unipeel TR6".

[0037] However, the temporary substrate does not need to contain the same common solvent as the specific resin layer at the time of manufacturing the transfer-type laminate. Typically, the common solvent penetrates the temporary substrate during the process of forming the specific resin layer on it, resulting in a temporary substrate containing the common solvent.

[0038] [3. Specific resin layer] The specific resin layer is formed on a temporary substrate. Typically, the specific resin layer is formed directly on the temporary substrate. When we say that the specific resin layer is formed "directly" on the temporary substrate, it means that the temporary substrate and the specific resin layer are in contact, and there are no other layers between the temporary substrate and the specific resin layer.

[0039] The specific resin layer is formed of a second resin, which is a thermoplastic resin containing a polymer and a common solvent. Therefore, the specific resin layer contains the second resin, preferably only the second resin. Typically, because the polymer is thermoplastic, the second resin may also be thermoplastic. In the following description, the polymer contained in the second resin may be referred to as the "second polymer."

[0040] The specific resin layer formed with the second resin contains the same common solvent as the common solvent contained in the temporary substrate. This common solvent may be the residual solvent that remained after drying from the solvent contained in the resin liquid used in the process of forming the specific resin layer. As this common solvent, an organic solvent is preferred, and an organic solvent capable of dissolving the second polymer is particularly preferred. Examples of common solvents include hydrocarbon solvents such as cyclohexane, alkylcyclohexane (methylcyclohexane, ethylcyclohexane, etc.), and toluene; cyclic ether solvents such as tetrahydrofuran; and so on. The common solvent may be used alone or in combination of two or more types.

[0041] The content of the common solvent in the specific resin layer is preferably within a specific range relative to 100% by weight of the specific resin layer. This specific range of the common solvent content is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, particularly preferably 0.5% by weight or more, preferably 10% by weight or less, more preferably 9% by weight or less, and particularly preferably 8.5% by weight or less. Furthermore, the content of the common solvent in the second resin is preferably within the same specific range as the content of the common solvent in the specific resin layer relative to 100% by weight of the specific resin layer. When the content of the common solvent is within the above range, the peel force between the temporary substrate and the specific resin layer can be adjusted to an appropriate range. In addition, the mechanical strength of the specific resin layer can usually be increased, so that the fracture of the specific resin layer can be suppressed when bonding the specific resin layer to another component, and thus the transfer of the specific resin layer can be performed particularly smoothly.

[0042] The content of the common solvent in the specific resin layer can be adjusted, for example, by the type of common solvent, the thickness of the specific resin layer, and the drying temperature and drying time of the resin liquid during the formation of the specific resin layer.

[0043] The content of the common solvent in a specific resin layer can be measured using a gas chromatograph-mass spectrometer. The specific measurement method can be the one described in the examples.

[0044] Examples of secondary polymers included in the secondary resin include polyester, acrylic polymers, and polymers containing alicyclic structures. These secondary polymers may be used individually or in combination of two or more types. Among these, polymers containing alicyclic structures are preferred from the viewpoint of lowering the water vapor permeability of the specific resin layer.

[0045] Polymers containing alicyclic structures have repeating units that contain alicyclic structures. Polymers containing alicyclic structures typically have low water vapor permeability. Therefore, when a specific resin layer is formed using a secondary resin containing a polymer with an alicyclic structure, a specific resin layer with low water vapor permeability can be obtained.

[0046] Polymers containing alicyclic structures may contain alicyclic structures in the main chain, in the side chains, or in both the main chain and side chains. Among these, polymers containing alicyclic structures in at least the main chain are preferred from the viewpoint of mechanical strength and heat resistance.

[0047] Examples of alicyclic structures include saturated alicyclic hydrocarbon (cycloalkane) structures and unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structures. Among these, cycloalkane and cycloalkene structures are preferred from the viewpoint of mechanical strength and heat resistance, and cycloalkane structures are particularly preferred.

[0048] The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less per alicyclic structure. When the number of carbon atoms constituting the alicyclic structure is within this range, the mechanical strength, heat resistance, and moldability of the second resin are highly balanced.

[0049] In polymers containing alicyclic structures, the proportion of repeating units containing alicyclic structures can be appropriately selected depending on the intended use. The proportion of repeating units containing alicyclic structures in polymers containing alicyclic structures is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the proportion of repeating units containing alicyclic structures in polymers containing alicyclic structures falls within this range, the transparency and heat resistance of the secondary resin are good.

[0050] Examples of polymers containing alicyclic structures include norbornene polymers, monocyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and their hydrides. Among these, norbornene polymers and their hydrides exhibit good transparency and moldability.

[0051] Examples of norbornene polymers and their hydrides include ring-opening polymers of monomers having a norbornene structure and their hydrides; and addition polymers of monomers having a norbornene structure and their hydrides. Examples of ring-opening polymers of monomers having a norbornene structure include ring-opening homopolymers of one type of monomer having a norbornene structure, ring-opening copolymers of two or more types of monomers having a norbornene structure, and ring-opening copolymers of monomers having a norbornene structure and any monomer copolymerizable therewith. Furthermore, examples of addition polymers of monomers having a norbornene structure include addition homopolymers of one type of monomer having a norbornene structure, addition copolymers of two or more types of monomers having a norbornene structure, and addition copolymers of monomers having a norbornene structure and any monomer copolymerizable therewith. Examples of these polymers include those disclosed in Japanese Patent Application Publication No. 2002-321302, etc.

[0052] Specific examples of norbornene polymers and their hydrides include "Zeonor" manufactured by Zeon Corporation; "Arton" manufactured by JSR Corporation; and "TOPAS" manufactured by TOPAS Advanced Polymers.

[0053] The weight-average molecular weight Mw of the second polymer is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more, preferably 100,000 or less, more preferably 80,000 or less, and particularly preferably 50,000 or less. When the weight-average molecular weight is within this range, the mechanical strength and moldability of the second resin are highly balanced.

[0054] The molecular weight distribution (Mw / Mn) of the second polymer is preferably 1.2 or higher, more preferably 1.5 or higher, particularly preferably 1.8 or higher, preferably 3.5 or lower, more preferably 3.0 or lower, and particularly preferably 2.7 or lower. Here, Mn represents the number-average molecular weight. When the molecular weight distribution is above the lower limit of the above range, the productivity of the second polymer can be increased and manufacturing costs can be suppressed. Furthermore, when the molecular weight distribution is below the upper limit of the above range, the amount of low molecular weight components is reduced, which can suppress relaxation during high-temperature exposure and improve the stability of the specific resin layer.

[0055] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) mentioned above can be measured using gel permeation chromatography (GPC). Examples of solvents used in GPC include cyclohexane, toluene, and tetrahydrofuran. When using GPC, the weight-average molecular weight can be measured, for example, as the relative molecular weight in terms of polyisoprene or polystyrene.

[0056] The glass transition temperature of the second polymer is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower. When the glass transition temperature of the second polymer is within the above range, the durability of the polarizing film in high-temperature environments can be increased. The glass transition temperature can be measured using a differential scanning calorimeter (DSC) by raising the temperature at 10°C / min.

[0057] The content of the secondary polymer in the specific resin layer is preferably within a specific range relative to 100% by weight of the specific resin layer. This specific range of secondary polymer content is preferably 70% by weight or more, more preferably 80% by weight or more, even more preferably 90% by weight or more, preferably 99.99% by weight or less, even more preferably 99.9% by weight or less, even more preferably 99% by weight or less, and particularly preferably 96% by weight or less. Furthermore, the content of the secondary polymer in the second resin relative to 100% by weight of the total amount of the second resin is preferably within the same specific range as the content of the secondary polymer in the specific resin layer relative to 100% by weight of the specific resin layer. When the content of the secondary polymer is above the lower limit of the above range, the mechanical strength of the specific resin layer can be increased. Therefore, when the specific resin layer is bonded to the polarizer layer, the polarizer layer can be stably protected. Furthermore, when the content of the secondary polymer is below the upper limit of the above range, the adhesion between the temporary substrate and the specific resin layer can be effectively increased, so the peeling force between the temporary substrate and the specific resin layer can be effectively increased.

[0058] The second resin may contain an ultraviolet absorber as an optional component in combination with the second polymer and common solvent. Therefore, the specific resin layer formed from the second resin may also contain an ultraviolet absorber as an optional component. Examples of such ultraviolet absorbers include triazine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, and acrylonitrile-based ultraviolet absorbers. Examples of preferred ultraviolet absorbers include benzotriazole-based ultraviolet absorbers such as 2-(2H-benzotriazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazole-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, and 2-(2'-hydroxy-3'-t-butyl-5'-merylphenyl)-5-chlorobenzotriazole. The ultraviolet absorber may be used alone or in combination of two or more types.

[0059] In particular, UV absorbers that can be dissolved in a common solvent are preferred. By using UV absorbers that can be dissolved in a common solvent, the UV absorber can be easily distributed in a specific resin layer with high uniformity. Therefore, a specific resin layer with uniform and high UV blocking ability can be obtained.

[0060] Since a hydrocarbon solvent or a cyclic ether solvent is preferred as the common solvent, the ultraviolet absorber is particularly preferred to be one that can dissolve in the hydrocarbon solvent or cyclic ether solvent at a high concentration. Specifically, the ultraviolet absorber is preferably one that can dissolve in the hydrocarbon solvent or cyclic ether solvent at a concentration of preferably 2% by weight or more, more preferably 5% by weight or more, and particularly preferably 10% by weight or more. There is no upper limit to the concentration of the ultraviolet absorber that can dissolve in the hydrocarbon solvent or cyclic ether solvent, but it is usually 90% by weight or less. The above concentration represents the concentration when the weight of the solution obtained by dissolving the ultraviolet absorber in the hydrocarbon solvent or cyclic ether solvent is taken as 100%.

[0061] Preferably, the content of the ultraviolet absorber in the specific resin layer is within a specific range relative to 100% by weight of the specific resin layer. This specific range of ultraviolet absorber content is preferably 2% by weight or more, more preferably 5% by weight or more, particularly preferably 10% by weight or more, preferably 40% by weight or less, more preferably 35% by weight or less, and particularly preferably 30% by weight or less. Furthermore, preferably, the content of the ultraviolet absorber in the second resin is within the same specific range as the content of the ultraviolet absorber in the specific resin layer relative to 100% by weight of the specific resin layer. When the content of the ultraviolet absorber is within the above range, the specific resin layer can obtain a high ultraviolet blocking ability.

[0062] The second resin may contain any additional components in combination with the second polymer, common solvent, and ultraviolet absorber. Examples of optional components include hygroscopic agents, dispersants, organometallic compounds, stabilizers such as antioxidants and light stabilizers, resin modifiers such as lubricants and plasticizers, colorants such as dyes and pigments, and antistatic agents. Any of these components may be used individually or in combination of two or more.

[0063] The second resin preferably has a low water vapor permeability. Specifically, the water vapor permeability of the second resin per 100 μm thickness is preferably 4.0 g / (m²). 2 • day) or less, more preferably 3.0 g / (m 2 • day) or less, particularly preferably 2.0 g / (m 2 It is less than or equal to (day). The lower limit is ideally 0 g / (m 2 • day) or more, and 0.1 g / (m 2 It may be more than (day). If the second resin has a low water vapor permeability as described above, the polarizer layer can be stably protected by the specific resin layer. Therefore, deterioration of the polarizer layer due to moisture can be effectively suppressed, and thus the decrease in the polarization degree of the polarizer layer can be suppressed. Furthermore, since the bleed-out of iodine in the polarizer layer due to moisture that has penetrated the polarizer layer can be suppressed, the corrosion of metal parts such as electrodes in the display device by that iodine can be effectively suppressed.

[0064] The water vapor transmission rate per 100 μm thickness of the second resin forming the specific resin layer can be measured by the following method. The water vapor transmission rate of the specific resin layer is measured using a water vapor transmission rate measuring device ("PERMATRAN-W" manufactured by MOCON Corporation) according to JIS K 7129 B method, under conditions of a temperature of 40°C and a humidity of 90% RH. This measured water vapor transmission rate is multiplied by "100 (μm) / thickness of the specific resin layer (μm)" to convert it to a value per 100 μm thickness, thereby obtaining the water vapor transmission rate per 100 μm thickness of the second resin.

[0065] The water vapor permeability of the second resin can be adjusted, for example, by the type and amount of the second polymer contained in the second resin.

[0066] The photoelastic constant of the second resin preferably falls within a specific range. Specifically, the smaller the photoelastic constant of the second resin, the more preferable it is, preferably 10×10 -13 cm 2 / dyn or less, more preferably 5×10 -13 cm 2 / dyn or less, particularly preferably 2×10 -13 cm 2 / dyn or less. The lower limit is usually 0.0×10 -13 cm 2 / dyn or more. When the photoelastic constant of the second resin is within the above range, the change in retardation due to the stress of expansion or contraction can be reduced, so that the display uniformity of the display device can be maintained. The photoelastic constant of the second resin can be obtained by calculation from the birefringence generated when stress is applied to the second resin. A specific measurement method may adopt the method described in the examples.

[0067] The molecules of the second polymer contained in the specific resin layer preferably have a low degree of orientation, and more preferably are not oriented. When the degree of orientation of the second polymer contained in the specific resin layer is small, the degree of entanglement of the molecules of the second polymer can be increased, so that the toughness of the specific resin layer can be enhanced. Therefore, the occurrence of unintended peeling of the temporary substrate accompanied by the breakage of the specific resin layer can be suppressed, and the peelability can be effectively improved. Also, usually, when the degree of orientation of the second polymer contained in the specific resin layer is small, the change in the polarization state of polarized light passing through the specific resin layer can usually be reduced and preferably eliminated. Therefore, when the specific resin layer is laminated with the polarizer layer, the change in the polarization state due to the specific resin layer can be suppressed, so that the control of the polarization state of the polarized light passing through the polarizing film including the specific resin layer and the polarizer layer can be simplified.

[0068] The degree of orientation of the molecules of the secondary polymer contained in a specific resin layer can be expressed by the optical anisotropy of the specific resin layer. Generally, when the degree of orientation of the molecules of the secondary polymer is small, the optical anisotropy of the specific resin layer is small. Therefore, it is preferable that the specific resin layer has small optical anisotropy in both the in-plane direction and the thickness direction, and it is even more preferable that it has optical isotropy.

[0069] Therefore, it is preferable that the in-plane retardation of the specific resin layer be small. Specifically, the in-plane retardation of the specific resin layer at a measurement wavelength of 550 nm is preferably 5 nm or less, more preferably 4 nm or less, even more preferably 3 nm or less, and particularly preferably 2 nm or less. Furthermore, the retardation in the thickness direction of the specific resin layer is preferably zero or close to zero. Specifically, the retardation in the thickness direction of the specific resin layer at a measurement wavelength of 550 nm is preferably -5 nm or more, more preferably -4 nm or more, even more preferably -3 nm or more, particularly preferably -2 nm or more, preferably 5 nm or less, more preferably 4 nm or less, even more preferably 3 nm or less, and particularly preferably 2 nm or less.

[0070] A specific resin layer containing molecules of a secondary polymer with a low degree of orientation can be formed by a method for forming the specific resin layer that can reduce the stress applied to the specific resin layer, such as the coating method described later.

[0071] The specific resin layer preferably has low ultraviolet light transmittance. For example, the light transmittance of the specific resin layer at a wavelength of 380 nm is preferably 45% or less, more preferably 40% or less, and particularly preferably 30% or less, with a lower limit of 0%. While it is possible to reduce transmittance by increasing the thickness of the specific resin layer, it is preferable from the viewpoint of thin film formation to satisfy these values ​​with a thickness of 9 μm or less. A specific resin layer with low ultraviolet light transmittance can effectively protect the polarizer layer from ultraviolet light. The light transmittance of the specific resin layer at a wavelength of 380 nm can be measured using a spectrophotometer (for example, "V-7200" manufactured by JASCO Corporation). Specific measurement conditions can be those described in the examples.

[0072] The specific resin layer is preferably transparent from the viewpoint of functioning as a protective film layer for polarizing plates as an optical film. Therefore, it is preferable that the total light transmittance of the specific resin layer is high. The specific total light transmittance of the specific resin layer is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. The total light transmittance can be measured using an ultraviolet-visible spectrometer in the wavelength range of 400 nm to 700 nm.

[0073] The haze of the specific resin layer is preferably 5% or less, more preferably 3% or less, particularly preferably 1% or less, and ideally 0%. The haze can be measured using a haze meter in accordance with JIS K7361-1997.

[0074] The specific resin layer is preferably thin. The specific thickness of the specific resin layer is usually greater than 0 μm, preferably 1 μm or more, more preferably 1.5 μm or more, preferably 9 μm or less, more preferably 6 μm or less, and particularly preferably 5 μm or less. Even if the specific resin layer is this thin, it can effectively protect the polarizer layer, so a thin polarizing film can be obtained.

[0075] [4. Any layer] The transfer-type laminate may further include any additional layer in combination with the temporary substrate and the specific resin layer. For example, any additional layer may be provided on the side of the temporary substrate opposite to the specific resin layer. However, it is preferable that the transfer-type laminate does not include any additional layer and consists only of the temporary substrate and the specific resin layer.

[0076] [5. Peeling force between the temporary substrate and the specific resin layer] The temporary substrate and the specific resin layer have a peel force within a specific range. Specifically, the peel force is usually greater than 0.1 N / 25 mm, preferably greater than 0.12 N / 25 mm, particularly preferably greater than 0.15 N / 25 mm, and usually less than 2.5 N / 25 mm, preferably less than 2.0 N / 25 mm, particularly preferably less than 1.5 N / 25 mm.

[0077] When the peeling force between the temporary substrate and the specific resin layer is within the aforementioned range, excellent transferability of the specific resin layer can be obtained. More specifically, when the peeling force is greater than the lower limit of the aforementioned range, unintended peeling between the temporary substrate and the specific resin layer can be suppressed, thus enabling smooth handling during the manufacturing, storage, transportation, and bonding of the transfer-type laminate. Therefore, when transferring the specific resin layer of a transfer-type laminate from a temporary substrate to a certain component (e.g., a polarizer layer), stable bonding between the specific resin layer and the component can be achieved. Furthermore, when the peeling force is less than the upper limit of the aforementioned range, the temporary substrate can be easily peeled off. Therefore, damage to the specific resin layer due to the peeling of the temporary substrate can be suppressed.

[0078] The inventors surmise the mechanism by which the excellent transferability described above is obtained as follows. However, the technical scope of the present invention is not limited by the mechanism described below. When a temporary substrate and a specific resin layer contain the same common solvent, a portion can be formed at the interface between the temporary substrate and the specific resin layer where the materials of the temporary substrate, the specific resin layer, and the common solvent are mixed. This portion may be referred to as the "intermediate portion" below. Because the materials of the temporary substrate and the specific resin layer are mixed in this intermediate portion, it can have an appropriate range of affinity to both the temporary substrate and the specific resin layer. Therefore, the affinity of the intermediate portion can increase the adhesion between the temporary substrate and the specific resin layer via the intermediate portion. On the other hand, the thickness of the intermediate portion is generally small. Furthermore, because the materials of the temporary substrate and the specific resin layer are mixed in the intermediate portion, it may contain minute-level phase interfaces that can become the starting point for stress-induced fracture. Therefore, since the intermediate portion can be easily fractured when peel stress is applied, the adhesion between the temporary substrate and the specific resin layer via the intermediate portion does not become excessively high. Thus, the peeling force between the temporary substrate and the specific resin layer can remain within the appropriate range, enabling excellent transferability.

[0079] The ease of formation, thickness, and mechanical strength of the intermediate layer are generally influenced by the content of the common solvent in the specific resin layer. Furthermore, the ease of formation, thickness, and mechanical strength of the intermediate layer may also be influenced by the content of the common solvent in the temporary substrate. Therefore, excellent transferability is obtained when the content of the common solvent in the specific resin layer is within a specific range, and particularly excellent transferability is obtained when both the content of the common solvent in the specific resin layer and the content of the common solvent in the temporary substrate are within a specific range.

[0080] Furthermore, the thickness of the intermediate portion may be affected by the deformability of the temporary substrate when it is heated. The intermediate portion is usually formed in the process of coating the temporary substrate with a resin liquid and drying it to form a specific resin layer. Also, the temporary substrate may be heated during the drying process. For example, if the heated temporary substrate shrinks significantly as described above, stress in the thickness direction is generated within the temporary substrate, promoting the penetration of the temporary substrate material into the intermediate portion, which may increase the thickness of the intermediate portion and thus increase the peel force. Conversely, if the heated temporary substrate expands significantly as described above, stress in the in-plane direction perpendicular to the thickness direction is generated within the temporary substrate, suppressing the penetration of the temporary substrate material into the intermediate portion, which may decrease the thickness of the intermediate portion and thus decrease the peel force. Therefore, in order to suppress the deformability of the temporary substrate when it is heated, if the dimensional change rate when a heating test is performed is within a specific range, it is easier to keep the peel force within an appropriate range, and particularly excellent transferability can be obtained.

[0081] The peel force between the temporary substrate and the specific resin layer can be measured by the following method: The specific resin layer of the transfer-type laminate is bonded to a rigid flat plate (e.g., a soda glass plate) and fixed in place. A portion of the temporary substrate is peeled off. The peeled portion is pulled at a speed of 300 mm / min in a 90-degree direction (i.e., the direction normal to the main surface of the resin layer), and the peel force when the temporary substrate is peeled off can be measured using a peel force measuring instrument (e.g., IMADA "MX-500N-L550-E").

[0082] The peeling force between the temporary substrate and the specific resin layer can usually be adjusted by controlling the content of the common solvent in the specific resin layer. Furthermore, the peeling force can be adjusted even more effectively by controlling the content of the common solvent in the temporary substrate and the dimensional change rate of the temporary substrate when heated at 120°C for 15 minutes.

[0083] [6. Flatness of transfer-type laminates] The transfer-type laminate preferably has high flatness. Specifically, the transfer-type laminate preferably has minimal deformation such as troughs and folds, and preferably has a flat shape without such deformation. The specific resin layer in such a highly flat transfer-type laminate can have high flatness. Therefore, when the specific resin layer is bonded to the polarizer layer as a polarizer protective film layer, it is possible to suppress unintended light reflection and refraction in the polarizing film containing the specific resin layer, thereby obtaining a high-quality polarizing film.

[0084] A transfer-type laminate with high flatness can be obtained, for example, by using a temporary substrate in which the dimensional change rate when subjected to a heating test is within a specific range.

[0085] [7. Dimensional change rate of transfer-type laminates] Since the temporary substrate of the transfer-type laminate preferably has a dimensional change rate within a specific range when subjected to a heating test, it is preferable that the dimensional change rate of the transfer-type laminate when subjected to a heating test is within the same specific range as that of the temporary substrate. Specifically, the dimensional change rate of the transfer-type laminate when subjected to a heating test of heating at 120°C for 15 minutes is preferably -0.4% or more, more preferably -0.3% or more, particularly preferably -0.2% or more, preferably 1.3% or less, more preferably 0.8% or less, and particularly preferably 0.5% or less. The above dimensional change rate represents the dimensional change rate in the width direction of the transfer-type laminate. Furthermore, a positive value of this dimensional change rate indicates that the transfer-type laminate expands, and a negative value indicates that the transfer-type laminate contracts.

[0086] The dimensional change rate of the transfer-type laminate can be measured using the same method as the dimensional change rate of the temporary substrate. Specifically, it can be measured using the following method. A transfer-type laminate is cut into a 150mm square, and a 100mm square is drawn in the center. Two sides of this square are drawn parallel to the width direction of the transfer-type laminate (corresponding to the width direction of a long transfer-type laminate). Using a universal projector (Nikon "PROFILE PROJECTOR V-12B"), the distance between the vertices of the drawn square is measured in the width direction of the transfer-type laminate to obtain the spacing before the heating test. Then, a heating test is performed by heating the transfer-type laminate at 120°C for 15 minutes. After the transfer-type laminate has cooled to room temperature, the distance between the vertices of the drawn square is measured again in the width direction of the transfer-type laminate to obtain the spacing after the heating test. The dimensional change of the transfer-type laminate due to the heating test is obtained by subtracting the spacing before the heating test from the spacing after the heating test. The dimensional change rate due to the heating test can be calculated by dividing this dimensional change by the spacing before the heating test.

[0087] [8. Method for manufacturing transfer-type laminates] A transfer-type laminate can be manufactured by a manufacturing method comprising: (i) coating a temporary substrate with a resin solution containing a second polymer and a common solvent; and (ii) drying the resin solution coated on the temporary substrate. This manufacturing method may be carried out using a single-sheet temporary substrate, but it is preferable to use a long temporary substrate. When a long temporary substrate is used, a long transfer-type laminate can be manufactured continuously. This manufacturing method will be described in detail below.

[0088] [8.1. Process of applying resin liquid to the temporary substrate (i)] In the method for manufacturing the transfer-type laminate described above, step (i) is performed to coat a temporary substrate with resin liquid. The temporary substrate can be one of those described above. It is preferable that the temporary substrate to which the resin liquid is coated in this manner has a dimensional change rate within the specific range described above when subjected to a heating test in which it is heated at 120°C for 15 minutes.

[0089] Since the resin liquid is a liquid material for forming a specific resin layer, it typically contains the components that may be included in the specific resin layer. Specifically, the resin liquid may contain a solvent, a second polymer, and any components that may be included in the specific resin layer as needed. The solvent of the resin liquid includes a common solvent, and preferably contains only the common solvent. Some or all of the non-volatile components, such as the second polymer and any other components, contained in the resin liquid may be dissolved in the solvent. Also, some or all of the non-volatile components may be dispersed in the solvent.

[0090] The solvent for the resin liquid may be a combination of the common solvent and any other solvent, but it is preferable to include only the common solvent. The types of common solvent are as described above. The common solvent may be used alone or in combination of two or more types. Similarly, any other solvent may be used alone or in combination of two or more types.

[0091] The concentration of non-volatile components in the resin liquid can be arbitrarily set within a range where the resin liquid has a viscosity suitable for coating. The specific concentration range is preferably 5% by weight or more, more preferably 10% by weight or more, particularly preferably 13% by weight or more, preferably 35% by weight or less, more preferably 30% by weight or less, and particularly preferably 25% by weight or less.

[0092] Methods for coating a temporary substrate with resin liquid include, for example, curtain coating, extrusion coating, roll coating, spin coating, dip coating, bar coating, spray coating, slide coating, printing coating, gravure coating, die coating, gap coating, and dipping.

[0093] In step (i), a layer of resin liquid is formed on the temporary substrate by coating it with the resin liquid. In addition, some of the common solvent contained in the resin liquid penetrates into the temporary substrate.

[0094] [8.2. Process of drying the resin liquid applied to the temporary substrate (ii)] As described above, by coating the temporary substrate with the resin liquid in step (i), a layer of resin liquid is formed on the temporary substrate. Therefore, after coating the temporary substrate with the resin liquid, step (ii) is performed to dry the resin liquid on the temporary substrate. During drying in step (ii), most of the volatile components such as the solvent are removed from the layer of resin liquid, but at least a portion of the common solvent remains. Therefore, during drying in step (ii), a specific resin layer containing the second polymer and the common solvent is formed on the temporary substrate. In addition, during drying in step (ii), some of the common solvent that has penetrated the temporary substrate may be removed, but at least a portion of that common solvent may remain in the temporary substrate. Therefore, a temporary substrate containing the common solvent is obtained.

[0095] The drying conditions for the resin liquid are set so that the content of the common solvent in the specific resin layer obtained after drying falls within the specified range described above. For example, by appropriately setting drying conditions such as drying temperature and drying time, the content of the common solvent in the specific resin layer can be adjusted to a specific range.

[0096] The specific drying temperature may vary depending on the type and amount of the second polymer and common solvent, but generally, it is preferably 90°C or higher, more preferably 100°C or higher, particularly preferably 110°C or higher, preferably 140°C or lower, more preferably 135°C or lower, and particularly preferably 130°C or lower.

[0097] The specific drying time may vary depending on the type and amount of polymer, reverse plasticizer, and solvent, but generally it is preferably 30 seconds or more, more preferably 60 seconds or more, particularly preferably 90 seconds or more, preferably 5 minutes or less, more preferably 4 minutes or less, and particularly preferably 3 minutes or less.

[0098] [8.3. Optional Steps] The method for manufacturing the transfer-type laminate may include any additional steps in combination with steps (i) and (ii) described above. For example, the method for manufacturing the transfer-type laminate may include any additional steps such as trimming the manufactured transfer-type laminate or winding the manufactured transfer-type laminate into a roll.

[0099] [9. Method for manufacturing polarizing film] The above-described transfer-type laminate can be applied to a method for manufacturing a polarizing film having a specific resin layer. For example, the transfer-type laminate is Step (I) involves bonding the polarizer layer to a specific resin layer of the transfer-type laminate, Step (II) of peeling off the temporary substrate of the transfer-type laminate, This method can be applied to a method for manufacturing polarizing films containing [specific material]. The method for manufacturing this polarizing film will be described in detail below.

[0100] [9.1. Process of bonding the polarizer layer and the specific resin layer (I)] A method for manufacturing a polarizing film includes a step (I) of bonding a polarizer layer to a specific resin layer of a transfer-type laminate. As the polarizer layer, a film can be used that transmits one of two linearly polarized rays whose vibration directions intersect at right angles, and absorbs or reflects the other. Here, the vibration direction of linearly polarized rays refers to the vibration direction of the electric field of the linearly polarized rays. Such a film usually has a polarization transmission axis and can transmit linearly polarized rays having a vibration direction parallel to the polarization transmission axis, and can absorb or reflect linearly polarized rays having a vibration direction perpendicular to the polarization transmission axis.

[0101] The polarizer layer may be obtained by subjecting a polyvinyl alcohol resin film, which contains a vinyl alcohol-based polymer such as polyvinyl alcohol or partially formalized polyvinyl alcohol, to appropriate treatments such as dyeing with a dichroic substance such as iodine, stretching, and crosslinking in an appropriate order and manner. It is preferable that the polarizer layer contains polyvinyl alcohol resin.

[0102] The thickness of the polarizer layer is preferably greater than 1 μm, more preferably 2 μm or more, particularly preferably 3 μm or more, preferably 19 μm or less, and more preferably 18 μm or less. When the thickness of the polarizer layer is greater than the lower limit, the optical performance of the polarizing film can be sufficiently improved. Furthermore, when the thickness of the polarizer layer is less than or equal to the upper limit, the warping of the display body equipped with the polarizing film can be reduced, and the bending recovery of the polarizing film can be effectively improved.

[0103] The bonding of the specific resin layer and the polarizer layer may be carried out via an adhesive, if necessary. Examples of adhesives include acrylic adhesives, epoxy adhesives, urethane adhesives, polyester adhesives, polyvinyl alcohol adhesives, modified polyvinyl alcohol adhesives, polyolefin adhesives, modified polyolefin adhesives, polyvinyl alkyl ether adhesives, rubber adhesives, vinyl chloride-vinyl acetate adhesives, SEBS (styrene-ethylene-butylene-styrene copolymer) adhesives, ethylene-styrene copolymers and other ethylene-based adhesives, acrylic acid ester adhesives such as ethylene-(meth)acrylate methyl copolymer and ethylene-(meth)acrylate ethyl copolymer. From the viewpoint of enabling rapid curing of the adhesive, UV-curing adhesives are preferred, but from the viewpoint of making the adhesive layer thinner, water-based adhesives of polyvinyl alcohol or modified polyvinyl alcohol may also be used.

[0104] When a specific resin layer and a polarizer layer are bonded together using an adhesive, an adhesive layer is usually formed between the specific resin layer and the polarizer layer. The thickness of the UV-curable adhesive layer is usually greater than 0 μm, preferably 0.1 μm or more, more preferably 1 μm or more, preferably 5 μm or less, and more preferably 3 μm or less. The thickness of the water-based adhesive is usually greater than 0 μm, preferably 0.02 μm or more, more preferably 0.04 μm or more, preferably 0.1 μm or less, and more preferably 0.08 μm or less. When the thickness of each adhesive layer is within the above range, a good appearance can be obtained, and the specific resin layer and the polarizer layer can be strongly bonded.

[0105] There are no particular restrictions on the specific method of bonding the polarizer layer and the specific resin layer. For example, a long specific resin layer and a long polarizer layer may be bonded together using an adhesive, if necessary, and a bonding tool such as a pinch roller.

[0106] Although the specific resin layer contains a common solvent, the content of the common solvent is within the specific range described above, so the specific resin layer can have sufficient mechanical strength to prevent it from easily breaking. Therefore, even if stress for bonding is applied to the specific resin layer during the bonding of the specific resin layer and the polarizer layer in process (I), the breaking of the specific resin layer can be suppressed. Thus, the bonding of the specific resin layer and the polarizer layer can be carried out while suppressing the breaking of the specific resin layer.

[0107] [9.2. Step of removing the temporary substrate (II)] The method for manufacturing a polarizing film includes a step (II) of peeling off a temporary substrate. This step (II) may be performed before step (I) or simultaneously with step (I), but it is preferable to perform it after step (I) in order to ensure particularly smooth transfer of the specific resin layer from the temporary substrate to the polarizer layer. Since the peeling force between the temporary substrate and the specific resin layer is within the specific range described above, the peeling of the temporary substrate in step (II) can be performed smoothly. Therefore, deformation and damage of the specific resin layer due to the peeling of the temporary substrate can be suppressed.

[0108] Normally, the temporary substrate is peeled off continuously. In this case, the peeling speed of the temporary substrate is preferably 70 m / min or less, more preferably 60 m / min or less, and particularly preferably 50 m / min or less, from the viewpoint of effectively suppressing the rupture of the specific resin layer. There is no particular lower limit, but from the viewpoint of rapidly proceeding with the production of the polarizing film, it is preferably 10 m / min or more, more preferably 15 m / min or more, and particularly preferably 20 m / min or more.

[0109] In one example, steps (I) and (II) described above may be carried out as follows: A specific resin layer of the transfer-type laminate is bonded to both sides of the polarizer layer to obtain a film having the transfer-type laminate / polarizer layer / transfer-type laminate in this order (step (I)). Then, the temporary substrate of the transfer-type laminate on both sides of the polarizer layer is peeled off (step (II)). According to the method in this example, a polarizing film having the specific resin layer / polarizer layer / specific resin layer in this order can be obtained.

[0110] Alternatively, the polarizing film may be manufactured as a film comprising a transfer-type laminate / polarizer layer / transfer-type laminate in the order described above, and stored and transported as such a film. Since this film comprises a temporary substrate / specific resin layer / polarizer layer / specific resin layer / temporary substrate in the order described above, the specific resin layer and polarizer layer can be protected by the temporary substrate. In this case, the temporary substrate can be peeled off immediately before use to obtain a multilayer film, which can then be used for applications such as attachment to a display device.

[0111] [9.3. Step of applying an optional protective layer] In the method for manufacturing a polarizing film, by combining steps (I) and (II) described above, the specific resin layer may be provided on only one side of the polarizer layer, or on both sides of the polarizer layer. When the specific resin layer is provided on only one side of the polarizer layer, an arbitrary protective layer may be provided on the other side of the polarizer layer. Therefore, the method for manufacturing a polarizing film may optionally include a step of providing an arbitrary protective layer on the side of the polarizer layer opposite to the specific resin layer.

[0112] Any protective layer can be formed from any thermoplastic resin other than the second resin, for example. Examples of any thermoplastic resin that have excellent transparency, mechanical strength, thermal stability, and moisture barrier properties include acetate resins such as triacetylcellulose, polyester resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, cyclic olefin resins, and (meth)acrylic resins. Among these, (meth)acrylic resins and cyclic olefin resins are preferred because they provide a protective layer with high hardness and low water vapor permeability, and cyclic olefin resins are even more preferred because they have an even lower water vapor permeability. Any protective layer may be, for example, a flexible, ultrathin glass film.

[0113] There are no restrictions on the thickness of any protective layer. For example, the thickness of any thermoplastic resin layer or a protective layer such as ultrathin glass can range from 13 μm to 100 μm.

[0114] Any protective layer can be formed, for example, by a method that includes bonding any protective layer, formed from any thermoplastic resin or ultrathin glass, to the polarizer layer via an adhesive as needed. The adhesive used to bond the polarizer layer to the protective layer may be the same adhesive that can be used to bond a specific resin layer to the polarizer layer. When an adhesive is used, an adhesive layer may be formed between the polarizer layer and the protective layer, and the thickness range of this adhesive layer may be the same as the thickness range of the adhesive layer formed between the specific resin layer and the polarizer layer.

[0115] Any protective layer may be provided on the polarizer layer before the specific resin layer. Alternatively, any protective layer may be provided on the polarizer layer after the specific resin layer. Furthermore, any protective layer may be provided on the polarizer layer simultaneously with the specific resin layer.

[0116] When specific resin layers are provided on both sides of the polarizer layer, it is not necessary to peel off the temporary substrate from one of the specific resin layers. In this case, a transfer-type laminate including the specific resin layer and the temporary substrate can be used as a protective layer. For example, a polarizing film can be obtained that comprises a specific resin layer / polarizer layer / transfer-type laminate in this order.

[0117] [9.4. Step of providing an optional adhesive layer] A method for manufacturing a polarizing film may optionally include a step of providing an adhesive layer. The adhesive layer is usually provided as the outermost layer of the polarizing film. For example, the adhesive layer may be provided such that the polarizer layer, a specific resin layer, and the adhesive layer are arranged in this order in the thickness direction. Since the adhesive layer is formed by an adhesive, it can exert adhesive force. Therefore, the polarizing film can be bonded to other components by the adhesive force of the adhesive layer. For example, when incorporating a polarizing film into a display device equipped with a display element such as a liquid crystal panel or an organic electroluminescent panel (hereinafter, as may be referred to as an "organic EL panel"), the polarizing film can be provided on the display element by bonding the adhesive layer to the display element.

[0118] Examples of adhesives include rubber-based adhesives, acrylic-based adhesives, polyvinyl ether-based adhesives, urethane-based adhesives, silicone-based adhesives, and polyolefin-based adhesives. Among these, acrylic-based adhesives and polyolefin-based adhesives are preferred from the viewpoint of heat resistance and productivity, and acrylic-based adhesives are particularly preferred. Furthermore, one type of adhesive may be used alone, or two or more types may be used in combination.

[0119] The thickness of the adhesive layer is preferably 2.0 μm or more, more preferably 5.0 μm or more, preferably 30.0 μm or less, more preferably 25.0 μm or less, and particularly preferably 20.0 μm or less. When the thickness of the adhesive layer is greater than or equal to the lower limit, the adhesive strength of the adhesive layer can be increased, and the inclusion of air bubbles during bonding can be suppressed. Furthermore, when the thickness of the adhesive layer is less than or equal to the upper limit, the expansion and contraction behavior of the polarizing film can be suppressed, making bezel-free possible.

[0120] The adhesive layer may be formed, for example, by coating with an adhesive. Alternatively, the adhesive layer may be formed, for example, by laminating pre-prepared adhesive layers. There are no restrictions on the timing of forming the adhesive layer. For example, when manufacturing a polarizing film comprising a polarizer layer, a specific resin layer, and an adhesive layer in this order, the adhesive layer can usually be formed after the specific resin layer is formed on the polarizer layer.

[0121] [9.5. Step of providing an arbitrary λ / 4 layer] The method for manufacturing a polarizing film may optionally include a step of providing a λ / 4 layer. For example, when the polarizing film is used as an anti-reflective film for an organic EL panel, the λ / 4 layer may be provided between the polarizer layer and the organic EL panel. In this case, the polarizer layer, the specific resin layer, and the λ / 4 layer may be arranged in the order of (polarizer layer) / (specific resin layer) / (λ / 4 layer), or in the order of (specific resin layer) / (polarizer layer) / (λ / 4 layer). Adhesives and adhesive layers can be used in the method for manufacturing a polarizing film.

[0122] For example, when providing a λ / 4 layer for sunglass readability of an organic EL display or a liquid crystal panel, the λ / 4 can be provided between the polarizer layer and the viewer. At this time, the polarizer layer, the specific resin layer, and the λ / 4 layer may be provided in the order of viewer / (λ / 4 layer) / (polarizer layer) / (specific resin layer), or may be provided in the order of viewer / (λ / 4 layer) / (specific resin layer) / (polarizer layer). In the method for manufacturing a polarizing film, an adhesive and an adhesive layer can be used similarly.

[0123] The λ / 4 layer has an in-plane retardation within a specific range at a wavelength of 550 nm. Specifically, the in-plane retardation of the λ / 4 layer at a wavelength of 550 nm is preferably 110 nm or more, more preferably 120 nm or more, particularly preferably 125 nm or more, and preferably 165 nm or less, more preferably 155 nm or less, particularly preferably 150 nm or less.

[0124] The slow axis of the λ / 4 layer preferably forms an angle of 40° to 50°, more preferably 42° to 48°, particularly preferably 44° to 46° with respect to the polarization transmission axis of the polarizer layer. In this case, a circular polarizing plate can be obtained by the combination of the polarizer layer and the λ / 4 layer. Therefore, the polarizing film provided with the λ / 4 layer can function as a reflection suppression film when provided in a display device.

[0125] The λ / 4 layer preferably has inverse wavelength dispersion characteristics. The inverse wavelength dispersion characteristics refer to the property that the in-plane retardations Re(450) and Re(550) at the measurement wavelengths of 450 nm and 550 nm satisfy Re(450) < Re(550). The λ / 4 layer having inverse wavelength dispersion characteristics can exhibit its optical function in a wide wavelength range.

[0126] The λ / 4 layer may be manufactured, for example, as a stretched film obtained by stretching a pre-stretched film formed of a suitable resin. Further, the λ / 4 layer may be manufactured, for example, as a liquid crystal cured layer in which a layer of a liquid crystal composition containing a suitable liquid crystal compound is formed, the molecules of the liquid crystal compound are aligned, and then the liquid crystal composition is cured. Among these, from the viewpoint of obtaining a thin and flexible polarizing film, the λ / 4 layer is preferably a liquid crystal cured layer. Such a λ / 4 layer as a liquid crystal cured layer can be manufactured, for example, by the method described in International Publication No. 2016 / 121602.

[0127] The λ / 4 layer may be formed, for example, by laminating previously prepared λ / 4 layers. For this lamination, an adhesive may be used as necessary. As the adhesive used for laminating the λ / 4 layers, the same adhesive that can be used for laminating the specific resin layer and the polarizer layer can be used.

[0128] In order to expand the viewing angle, the refractive index of the λ / 4 layer may be controlled to nx>nz>ny, or a positive C plate (nx = ny < nz) or a negative C plate (nx = ny > nz), called a viewing angle compensation layer, may be laminated on the λ / 4 layer.

[0129] [9.6. Other Optional Processes] The method for manufacturing the polarizing film may further include an arbitrary process as necessary. For example, the method for manufacturing the polarizing film may include a process of providing an arbitrary layer such as a clear hard coat layer, an antiglare hard coat layer, an antireflection layer, an antistatic layer, an antifouling layer, a conductive layer, etc. on the polarizing film. The number of arbitrary layers may be 1 layer or 2 or more layers. Further, the position of the arbitrary layer is not limited as long as the effects of the present invention are not significantly impaired.

[0130] Furthermore, the method for manufacturing the polarizing film may include, for example, a step of curing the adhesive. Typically, the step of curing the adhesive is performed after the layers have been bonded together using the aforementioned adhesive. The method of curing the adhesive can be an appropriate method depending on the type of adhesive. For example, when using an ultraviolet-curing adhesive, the adhesive can be cured by irradiation with ultraviolet light.

[0131] Furthermore, the method for manufacturing a polarizing film may include a step of trimming the polarizing film. For example, a long polarizing film may be manufactured using a long polarizer layer and a long transfer-type laminate, and then the polarizing film may be trimmed to a desired size.

[0132] [9.7. Polarizing films manufactured] According to the above manufacturing method, the bonding of the polarizer layer and the specific resin layer, and the peeling off of the temporary substrate can be performed while suppressing deformation and damage of the specific resin layer. Therefore, the transfer of the specific resin layer from the temporary substrate to the polarizer layer can be performed smoothly, and a polarizing film comprising the polarizer layer and the specific resin layer can be manufactured smoothly.

[0133] The polarizing film produced may include any layers as needed, such as an adhesive layer, a protective layer, a tack layer, and a λ / 4 layer. For example, the polarizing film may include a protective layer, an adhesive layer, a polarizer layer, an adhesive layer, a specific resin layer, a λ / 4 layer, and a tack layer in that order.

[0134] Even if the specific resin layer is thin, the polarizer layer can be effectively protected, so it is usually possible to make the entire polarizing film thin. The thickness of the polarizing film is preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 70 μm or less. There is no particular lower limit to the thickness of the polarizing film; for example, in applications where the display is bent or folded, thinner is preferable.

[0135] [10.Display device] The polarizing film described above may be provided, for example, in a display device. A display device equipped with a polarizing film usually includes a display element in combination with the polarizing film. In this case, the polarizing film may be provided with a specific resin layer and a polarizer layer in that order from the display element side. This display device can be manufactured, for example, by a manufacturing method that includes laminating the display element and the polarizing film. However, the manufacturing method of the display device is not limited to this.

[0136] Examples of display elements include liquid crystal panels used as display elements for liquid crystal display devices, and organic EL panels used as display elements for organic electroluminescent display devices (hereinafter sometimes referred to as "organic EL display devices"). Typically, a polarizing film is provided on the viewing side of these display elements.

[0137] A liquid crystal panel typically comprises a liquid crystal cell, which includes liquid crystal and electrodes to which a voltage can be applied. The liquid crystal cell can be of any mode, such as in-plane switching (IPS) mode, vertical alignment (VA) mode, multi-domain vertical alignment (MVA) mode, continuous spinwheel alignment (CPA) mode, hybrid alignment nematic (HAN) mode, twisted nematic (TN) mode, super-twisted nematic (STN) mode, or optically compensated bend (OCB) mode.

[0138] An organic EL panel typically comprises an organic EL element having a transparent electrode layer, an emissive layer, and an electrode layer in that order. In this organic EL element, the emissive layer can emit light when a voltage is applied from the transparent electrode layer and the electrode layer. Examples of materials constituting the organic emissive layer include poly(p-phenylenevinylene), polyfluorene, and polyvinylcarbazole materials. The emissive layer may also have a laminate of multiple layers with different emission colors, or a mixed layer in which a layer of one dye is doped with a different dye. Furthermore, the organic EL element may include functional layers such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, an equipotential surface forming layer, and a charge generation layer. [Examples]

[0139] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples shown below, and can be modified and implemented as appropriate without departing from the scope of the claims and equivalents of the present invention.

[0140] In the following explanation, "%" and "parts" refer to weight unless otherwise specified. Furthermore, the operations described below were performed in ambient air at normal temperature and pressure (23°C, 1 atm) unless otherwise specified.

[0141] [Method for measuring solvent content] The transfer-type laminate was separated into a resin layer and a temporary substrate. The resin layer and temporary substrate were each cut to 40 mm x 200 mm, weighed, and placed in vials. The resin layer and temporary substrate were heated at 150°C for 30 minutes to vaporize the solvent in each, and the amount of vaporized solvent was measured using a gas chromatograph-mass spectrometer (Shimadzu GC-2010 Plus / Trubomatrix 40; column: Agilent Technologies DB-5ms). The specific amount of solvent was determined based on a pre-prepared calibration curve. The solvent content was calculated from the determined amount of solvent.

[0142] Furthermore, in Examples 4 and 5 in particular, the solvent content in the resin (release agent) contained in the release layer was measured by the following method. The transfer-type laminate was separated into a resin layer and a temporary substrate. After weighing 0.1 g of the temporary substrate, only the release agent was dissolved in toluene solution, filtered, and recovered to obtain the sample solution. The amount of solvent was measured using a gas chromatograph-mass spectrometer (Shimadzu Corporation "GCMS-QP2020" (column: Agilent Technologies "DB-1")). The specific amount of solvent was determined based on a pre-prepared calibration curve. From the determined amount of solvent, the solvent content was calculated, and the solvent content in the resin (release agent) contained in the release layer was measured.

[0143] [Method for measuring water vapor transmission rate] The resin layer was peeled off from the transfer-type laminate. The water vapor transmission rate of this resin layer was measured using a water vapor transmission rate measuring device (MOCON "PERMATRAN-W") in accordance with JIS K 7129 B method, under conditions of 40°C and 90% RH. The measured values ​​of water vapor transmission rate obtained in this way were converted to values ​​per 100 μm thickness to obtain the water vapor transmission rate per 100 μm thickness of the resin contained in the resin layer. Specifically, the measured value was multiplied by "100 (μm) / thickness of the specific resin layer (μm)" to obtain the water vapor transmission rate per 100 μm thickness.

[0144] [Measurement of photoelastic constant] The resin layer was peeled from the transfer-type laminate. This resin layer was cut to prepare several 1 cm wide film pieces. Weights of 50 g, 100 g, 150 g, and 200 g were suspended from these film pieces, and in-plane retardation was measured at a measurement wavelength of 550 nm. In-plane retardation was measured using a phase difference meter (AXOMETRICS "Axo Scan"). The measured in-plane retardation was divided by the thickness of the resin layer to obtain the birefringence. The obtained birefringence and the magnitude of the force per unit cross-sectional area applied to the resin layer by the weight corresponding to that birefringence were plotted on a coordinate system with the magnitude of the force on the horizontal axis and birefringence on the vertical axis. An approximate straight line was obtained from the obtained plot using the least squares method. The photoelastic constant of the resin layer was determined as the slope of this approximate straight line.

[0145] [Method for measuring retardation] The resin layer was peeled off from the transfer-type laminate. For this resin layer, the in-plane retardation Re and the thickness-direction retardation Rth were measured at a measurement wavelength of 550 nm using a phase difference meter (AXOMETRICS "Axo Scan").

[0146] [Method for measuring transmittance at 380nm] A glass substrate (Corning Eagle XG; 0.5 mm thick) was prepared. A resin layer of a transfer-type laminate was bonded to this glass substrate via an optical adhesive sheet (Nitto Denko LUCIACS CS9861US) using a hand roll. After that, the temporary substrate was peeled off to obtain a sample with a layer structure of glass substrate / optical adhesive sheet / resin layer. Since neither the glass substrate nor the optical adhesive sheet absorbs light at a wavelength of 380 nm, the light transmittance of the sample matches the light transmittance of the resin layer. Therefore, the light transmittance at a wavelength of 380 nm was measured using a spectrophotometer (JASCO V-7200).

[0147] [Method for measuring dimensional change rate] The dimensional change rates of film samples, such as temporary substrates and transfer-type laminates, were measured using the following method. A film sample (i.e., a temporary substrate or transfer-type laminate) was cut into a 150 mm square, and a 100 mm square was drawn in the center. Two sides of this square were drawn parallel to the width direction of the film sample (corresponding to the width direction of a long film sample). Using a universal projector (Nikon "PROFILE PROJECTOR V-12B"), the distance between the vertices of the square drawn on the film sample was measured in the width direction of the film sample to obtain the spacing before the heating test. Subsequently, a heating test was performed by heating the film sample at 120°C for 15 minutes. After the film sample was allowed to cool to room temperature, the distance between the vertices of the square drawn on the film sample was measured again in the width direction of the film sample to obtain the spacing after the heating test. The dimensional change of the film sample due to the heating test was obtained by subtracting the spacing before the heating test from the spacing after the heating test. The dimensional change rate of the film sample due to the heating test was calculated by dividing this dimensional change by the spacing before the heating test.

[0148] [Method for measuring peeling force] An optical adhesive sheet (Nitto Denko "LUCIACS CS9861US") was prepared, with a light release liner laminated to one side and a heavy release liner laminated to the other side. The light release liner was peeled off to expose one side of the optical adhesive sheet, and this exposed surface was laminated to a 2 mm thick soda glass plate. The heavy release liner was also peeled off to expose the other side of the optical adhesive sheet, and a resin layer of a transfer-type laminate was laminated to this exposed surface using a hand roll. A portion of the temporary substrate was peeled off using tape, and the peeling force when the peeled portion was pulled off at a speed of 300 mm / min in the 90-degree direction (i.e., the direction normal to the main surface of the resin layer) was measured using a peeling force meter (IMADA "MX-500N-L550-E").

[0149] [Method for evaluating transcriptional properties] As a long roll of raw film, an unstretched polyvinyl alcohol film (vinylon film, average degree of polymerization approximately 2400, degree of saponification 99.9 mol%) with a thickness of 20 μm was prepared. While continuously conveying this film longitudinally via guide rolls, the film was subjected to a treatment in which it was immersed in pure water at 30°C for 1 minute and stretched to twice its original size. Subsequently, the film was subjected to a dyeing treatment in which it was immersed in a dyeing solution (a dyeing solution containing iodine and potassium iodide in a weight ratio of 1:23, dyeing concentration 1.2 mmol / L) at 32°C for 2 minutes to adsorb iodine onto the film. After that, the film was immersed in a 3 wt% boric acid aqueous solution at 35°C for 30 seconds to crosslink and wash it. Then, at 57°C, the film was stretched to 3.0 times its original size in an aqueous solution containing 3 wt% boric acid and 5 wt% potassium iodide. Subsequently, the film was subjected to a complementary color treatment at 35°C in an aqueous solution containing 5% potassium iodide and 1.0% boric acid. The film was then dried at 70°C for 2 minutes to obtain a long polarizer layer with a thickness of 8 μm. The polarization degree of this polarizer layer was measured using a UV-Vis spectrophotometer (JASCO Corporation "V-7200") and was found to be 99.996%, indicating sufficient polarization ability.

[0150] The surface of the resin layer of the transfer-type laminate was subjected to corona treatment. Subsequently, an ultraviolet-curing adhesive (ADEKA's "Arkles KRX-7007") was applied to the corona-treated surface of the resin layer to form an adhesive layer. The resin layer and the polarizer layer were bonded together via this adhesive layer. Immediately after bonding, an ultraviolet irradiation device was used to apply 750 mJ / cm² from the temporary substrate side. 2 The adhesive was cured by UV irradiation. After that, the temporary substrate was peeled off, and the resin layer was transferred from the temporary substrate to the polarizer layer.

[0151] Based on the transfer characteristics of the resin layer and the peeling force of the temporary substrate from the resin layer, the transferability of the resin layer was evaluated according to the following criteria. "A": The peeling force is 0.1 / 25mm or more and 2.5N / 25mm or less, enabling stable web hand-dragging. "B": The peeling force is outside the range of 0.1 / 25mm to 2.5N / 25mm, and transfer defects may occasionally occur. "C": The peeling force is very low, making web hand-drying impossible. The resin layer peels off unintentionally and breaks.

[0152] [Method for evaluating film flatness] The transfer-type laminate was observed, and its film flatness was evaluated according to the following criteria. "A": No troughs are present in the transfer-type laminate. "B": Troughs are present in the transfer-type laminate. "C": Folds occur at the edges of the transfer-type laminate.

[0153] [Example 1] A norbornene polymer (ZEONOR, manufactured by Nippon Zeon Co., Ltd.; glass transition temperature 138°C) and cyclohexane were mixed as a solvent to obtain a resin solution with a concentration of 15% by weight of the norbornene polymer.

[0154] A long polypropylene film (Toray Industries' "New Type Trefan BO40-2500") was prepared as a temporary substrate. When the temporary substrate "New Type Trefan BO40-2500" was heated at 120°C for 15 minutes, the dimensional change rate in the width direction was 0.32%. The aforementioned resin solution was applied to the smooth surface of this temporary substrate to form a layer of resin solution. Subsequently, the layer of resin solution was dried at 120°C for 2 minutes to form a resin layer with a thickness of 9 μm on the temporary substrate. Through the above operations, a transfer-type laminate comprising a temporary substrate and a resin layer formed on this temporary substrate was obtained.

[0155] Using the obtained transfer-type laminate, the solvent content, water vapor transmission rate, photoelastic constant, in-plane retardation, thickness-direction retardation, and transferability of the resin layer; the solvent content, peeling force, and transferability of the temporary substrate; and the film flatness and dimensional change rate of the transfer-type laminate were evaluated using the method described above.

[0156] [Example 2] The transfer-type laminate was manufactured and evaluated using the same method as in Example 1, except that the amount of resin solution coated onto the temporary substrate was changed so that the thickness of the resin layer formed after drying was 5 μm.

[0157] [Example 3] The transfer-type laminate was manufactured and evaluated using the same method as in Example 1, except that the amount of resin solution coated onto the temporary substrate was changed so that the thickness of the resin layer formed after drying was 2 μm.

[0158] [Example 4] Instead of cyclohexane, a mixed solvent of cyclohexane and ethylcyclohexane (cyclohexane:ethylcyclohexane = 1:2) was used as the solvent for the resin solution. The type of temporary substrate was also changed to a long polyethylene terephthalate film (Unitika's "Unipeel TR1") with one side treated with a polyolefin-based release agent. This temporary substrate "Unipeel TR1" comprised a layer formed of polyethylene terephthalate and a release layer containing a polyolefin-based release agent formed on this layer. The dimensional change in the width direction when the temporary substrate "Unipeel TR1" was heated at 120°C for 15 minutes was -0.13%. The resin solution was applied to the side of the temporary substrate treated with the release agent (the release-coated side). Furthermore, instead of measuring the solvent content of the temporary substrate, the solvent content of the polyolefin-based release agent in the release layer was measured. Except for the above, the transfer-type laminate was manufactured and evaluated using the same method as in Example 3.

[0159] [Example 5] The type of temporary substrate was changed to a long polyethylene terephthalate film (Unitika's "Unipeel TR5") with one side treated with an olefin-based release agent. This temporary substrate "Unipeel TR5" consisted of a layer formed of polyethylene terephthalate and a release layer containing a polyolefin-based release agent formed on this layer. Furthermore, the dimensional change rate in the width direction when the temporary substrate "Unipeel TR5" was heated at 120°C for 15 minutes was -0.13%. Except for the above, the transfer-type laminate was manufactured and evaluated using the same method as in Example 4. [Example 6] A norbornene polymer (ZEONOR, manufactured by Zeon Corporation; glass transition temperature 138°C), an ultraviolet absorber (2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol; Tinuvin® 329, manufactured by BASF), and cyclohexane as a solvent were mixed to obtain a resin solution with a concentration of 11.7% by weight of norbornene polymer and 3.3% by weight of ultraviolet absorber. The ultraviolet absorber was soluble in cyclohexane, the solvent, up to a concentration of 16% by weight. Furthermore, the obtained resin solution contained 78% by weight of norbornene polymer and 22% by weight of ultraviolet absorber, based on 100% by weight of solids.

[0160] A long polypropylene film (Toray Industries' "New Type Trefan BO40-2500") was prepared as a temporary substrate. The aforementioned resin solution was applied to this temporary substrate to form a layer of resin solution. Subsequently, the layer of resin solution was dried at 120°C for 2 minutes to form a 5 μm thick resin layer on the temporary substrate. Through the above operations, a transfer-type laminate comprising a temporary substrate and a resin layer formed on this temporary substrate was obtained.

[0161] Using the obtained transfer-type laminate, the solvent content, water vapor transmittance, photoelastic constant, in-plane retardation, thickness-direction retardation, transferability, and light transmittance of the resin layer; the solvent content, peel strength, and transferability of the temporary substrate; and the film flatness and dimensional change rate of the transfer-type laminate were evaluated using the method described above.

[0162] [Comparative Example 1] The type of long temporary substrate was changed to a long polypropylene film (Toray Industries' "Trefan BO40-2500"). When the temporary substrate "Trefan BO40-2500" was heated at 120°C for 15 minutes, the dimensional change rate in the width direction was -0.95%. In addition, the amount of resin solution coated onto the smooth surface of the temporary substrate was changed so that the thickness of the resin layer formed after drying was 2 μm. Except for the above, the transfer-type laminate was manufactured and evaluated using the same method as in Example 1.

[0163] [Comparative Example 2] The type of long temporary substrate was changed to a long polyethylene terephthalate film (Toyobo Co., Ltd.'s "Cosmoshine A4160"). When the long polyethylene terephthalate film (Toyobo Co., Ltd.'s "Cosmoshine A4160") was heated at 120°C for 15 minutes, the dimensional change rate in the width direction was -0.15%. The resin solution was applied to the uneven surface of the temporary substrate after corona treatment. The amount of resin solution applied to the temporary substrate was also changed so that the thickness of the resin layer formed after drying was 2 μm. Except for the above, the transfer-type laminate was manufactured and evaluated using the same method as in Example 1.

[0164] [Comparative Example 3] The type of long temporary substrate was changed to a long polyethylene terephthalate film (Cosmoshine A4160, manufactured by Toyobo Co., Ltd.). The resin solution was applied to the smooth surface of the temporary substrate after corona treatment. Furthermore, the amount of resin solution applied to the temporary substrate was changed so that the thickness of the resin layer formed after drying was 2 μm. Except for the above, the transfer-type laminate was manufactured and evaluated using the same method as in Example 1.

[0165] [result] The results of the examples and comparative examples are shown in the table below. In the table below, the meanings of the abbreviations are as follows. COP: A polymer having an alicyclic structure. UVA: UV absorber. Re: In-plane lettering. Rth: Regression in the thickness direction. OPP1: Toray's polypropylene film "New Type Trefan BO40-2500". Release PET1: "Unipeel TR1," a polyethylene terephthalate film manufactured by Unitika Corporation, which has a release surface on one side. The resin solution was applied to the release surface. Release PET2: "Unipeel TR5," a polyethylene terephthalate film manufactured by Unitika Corporation, which has a release surface on one side. The resin solution was applied to the release surface. OPP2: Toray's polypropylene film "Trefan BO40-2500". Easy-to-bond PET: "Cosmoshine A4160," a polyethylene terephthalate film manufactured by Toyobo Co., Ltd., which has both a textured and a smooth surface. The resin solution was applied to the textured surface. PET: Toyobo's polyethylene terephthalate film "Cosmoshine A4160" has both a textured and a smooth surface. The resin solution was applied to the smooth surface.

[0166] [Table 1]

Claims

1. The device comprises a base material and a resin layer formed on the base material using a thermoplastic resin containing a polymer and a solvent. The aforementioned substrate comprises a first resin containing polyolefin or polyester, The polymer in the resin layer contains an alicyclic structure, The solvent comprises one or more selected from the group consisting of hydrocarbon solvents and cyclic ether solvents. The content of the solvent in the resin layer is 0.01% by weight to 10% by weight. The substrate contains the same solvent as the resin layer, A laminate in which the peel force between the substrate and the resin layer is greater than 0.1 N / 25 mm and less than 2.5 N / 25 mm.

2. The laminate according to claim 1, wherein the content of the solvent in the substrate is 0.05% by weight or more and 1.5% by weight or less.

3. The laminate according to claim 1 or 2, wherein the dimensional change rate in the width direction of the laminate when heated at 120°C for 15 minutes is -0.4% or more and 1.3% or less.

4. The water vapor transmission rate per 100 μm of thickness of the aforementioned thermoplastic resin is 4 g / (m²). ２ - The laminate according to any one of claims 1 to 3, wherein the number of days is less than or equal to the number of days.

5. The in-plane retardation of the resin layer at a measurement wavelength of 550 nm is 5 nm or less. The laminate according to any one of claims 1 to 4, wherein the retardation in the thickness direction of the resin layer at a measurement wavelength of 550 nm is -5 nm or more and 5 nm or less.

6. The laminate according to any one of claims 1 to 5, wherein the thickness of the resin layer is 9 μm or less.

7. The laminate according to any one of claims 1 to 6, wherein the resin layer contains 2% to 40% by weight of an ultraviolet absorber.

8. The laminate according to claim 7, wherein the ultraviolet absorber can be dissolved in a hydrocarbon solvent or a cyclic ether solvent at a concentration of 2% by weight or more.

9. The substrate comprises one or more layers, Of the layers provided by the substrate, the layer closest to the resin layer contains the first resin. The laminate according to any one of claims 1 to 8, wherein the content of the solvent in the first resin is 0.05% by weight or more and 1.5% by weight or less.

10. A method for manufacturing a laminate according to any one of claims 1 to 9, The process involves coating the substrate with a resin solution containing the polymer and the solvent, A method for manufacturing a laminate, comprising the step of drying a resin liquid coated onto the substrate.

11. The method for manufacturing a laminate according to claim 10, wherein the substrate to which the resin liquid is coated has a dimensional change rate in the width direction of -0.4% or more and 1.3% or less when heated at 120°C for 15 minutes.

12. A step of bonding a polarizer layer to the resin layer of the laminate according to any one of claims 1 to 9, A method for manufacturing a polarizing film, comprising the step of peeling off the substrate from the laminate.

13. The method for manufacturing a polarizing film according to claim 12, wherein the thickness of the polarizer layer is 19 μm or less.

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