WO2020004323A1 - Polarizing film and method for manufacturing same - Google Patents

Abstract

A polarizing film provided with a polarizer layer and a first resin layer in direct contact with the polarizer layer, the first resin layer being formed from a first resin having a storage modulus of 10 MPa to 1000 MPa measured with the resin in the form of a film having a thickness of 1 mm.

Description

Polarizing film and manufacturing method thereof

The present invention relates to a polarizing film and a method for producing the same.

表示 A display device such as a liquid crystal display device and an organic electroluminescence (EL) display device is often provided with a polarizing film. This polarizing film generally includes a polarizer layer and a protective film layer for protecting the polarizer layer.

Conventionally, protective film layers were usually provided on both sides of the polarizer layer. On the other hand, in order to reduce the thickness of the polarizing film, a technique has been proposed in which one protective film layer is omitted and a protective film layer is provided only on one side of the polarizer layer.

However, when a protective film layer is provided only on one side of the polarizer layer, there is a problem in durability of the polarizing film under a heating environment. Thus, Patent Document 1 proposes a technique in which a protective film layer is provided on one side of a polarizer layer, and a resin layer such as a polyvinyl alcohol resin and an acrylic resin is provided on the other side of the polarizer layer by a coating method. .

Japanese Patent No. 6078132 (corresponding publication: US Patent Application Publication No. 2017/299919)

However, the conventional polarizing film as disclosed in Patent Document 1 has low humidification reliability. Specifically, when a conventional polarizing film is stored in a high-humidity environment, the degree of polarization tends to greatly decrease.

In addition, the conventional polarizing film had low bending restorability. Specifically, when the conventional polarizing film is opened after being bent, it is difficult for the bent portion to return to the planar shape before bending. It is difficult to apply such a polarizing film to a flexible display device.

The present invention has been made in view of the above problems, and has as its object to provide a polarizing film excellent in both humidification reliability and bending restorability, and a method for manufacturing the same.

The present inventor has made intensive studies to solve the above-mentioned problems. As a result, the present inventor obtains a polarizing film excellent in both humidification reliability and flexural resilience by providing a resin layer having a predetermined storage modulus so as to be in direct contact with the polarizer layer. That is, they have completed the present invention.
That is, the present invention includes the following.

[1] a polarizer layer, comprising: a first resin layer directly in contact with the polarizer layer;
A polarizing film, wherein the first resin layer is formed of a first resin having a storage elastic modulus of 10 MPa or more and 1000 MPa or less measured as a film having a thickness of 1 mm.
[2] The polarizing film according to [1], wherein the thickness of the first resin layer is greater than 0 μm and 13 μm or less.
[3] The polarizing film according to [1] or [2], wherein the thickness of the polarizer layer is greater than 1 μm and 12 μm or less.
[4] The polarizer layer, the first resin layer, and the adhesive layer, in this order,
The polarizing film according to any one of [1] to [3], wherein the thickness of the adhesive layer is 2 μm or more and 25 μm or less.
[5] Any of [1] to [4], wherein the first resin has a water vapor transmission rate at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm of 4 g / (m ² · day) or less. 2. The polarizing film according to claim 1.
[6] The polarizing film according to any one of [1] to [5], wherein the first resin contains a polymer having an alicyclic structure.
[7] The polymer having the alicyclic structure,
A polymer block [A] having a repeating unit [I] derived from an aromatic vinyl compound as a main component,
A polymer block [B] containing a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a repeating unit [II] derived from a chain conjugated diene compound A polymer block [C] containing, as a main component,
The polarizing film according to [6], wherein the block copolymer [D] is a hydrogenated block copolymer.
[8] The polarizing film according to any one of [1] to [7], wherein the first resin contains a plasticizer and / or a softener.
[9] The polarizing film according to [8], wherein the plasticizer and / or softener is at least one selected from the group consisting of an ester plasticizer and an aliphatic hydrocarbon polymer.
[10]
The polarizing film according to any one of [1] to [9], wherein the first resin contains a moisture absorbent.
[11] The polarizing film according to any one of [1] to [10], wherein the first resin contains an organometallic compound.
[12] The first resin layer, the polarizer layer, and a second resin layer directly in contact with the polarizer layer, in this order,
The polarized light according to any one of [1] to [11], wherein the second resin layer is formed of a second resin having a storage elastic modulus of 10 MPa or more and 1000 MPa or less measured as a film having a thickness of 1 mm. the film.
[13] The method for producing a polarizing film according to any one of [1] to [12],
Preparing a first resin liquid containing the first resin,
Applying the first resin liquid to the polarizer layer.

According to the present invention, it is possible to provide a polarizing film excellent in both humidification reliability and bending resilience, and a method for producing the same.

FIG. 1 is a schematic sectional view of a polarizing film as a first example of the present invention. FIG. 2 is a schematic sectional view of a polarizing film as a second example of the present invention.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and equivalents thereof.

In the following description, a “long” film refers to a film having a length of 5 times or more with respect to the width of the film, preferably having a length of 10 times or more. Refers to those having a length that can be wound up in a roll and stored or transported. The upper limit of the ratio of the length to the width of the film is not particularly limited, but may be, for example, 100,000 times or less.

に お い て In the following description, the adhesive and the pressure-sensitive adhesive are distinguished by the shear storage modulus unless otherwise specified. Specifically, unless otherwise specified, the adhesive refers to a material having a shear storage modulus at 23 ° C. of 1 MPa to 500 MPa after irradiation with energy rays or heat treatment. Unless otherwise specified, the term “adhesive” refers to a material having a shear storage modulus at 23 ° C. of less than 1 MPa.

In the following description, “plate”, “layer” and “film” may be rigid members unless otherwise specified, for example, a member having flexibility such as a resin film. Is also good.

に お い て In the following description, the in-plane retardation Re of a certain layer is a value represented by Re = (nx−ny) × d unless otherwise specified. Here, nx represents the refractive index in the direction (in-plane direction) perpendicular to the thickness direction of the layer and in the direction giving the maximum refractive index. ny represents the refractive index in the in-plane direction of the layer and in a direction 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. The measurement wavelength is 550 nm unless otherwise specified.

[1. Overview of polarizing film]
A polarizing film according to an embodiment of the present invention includes a polarizer layer and a first resin layer directly in contact with the polarizer layer. “Direct contact” between the polarizer layer and the first resin layer indicates that there is no other layer between the polarizer layer and the first resin layer.

に お い て In the above-mentioned polarizing film, the first resin layer is formed of a first resin having a predetermined storage modulus. Thereby, the polarizing film can have excellent humidification reliability and bending resilience.

It is preferable that the polarizing film further includes a second resin layer directly in contact with the polarizer layer in combination with the polarizer layer and the first resin layer. In this case, the polarizing film includes a first resin layer, a polarizer layer, and a second resin layer in this order. “Directly” contact between the polarizer layer and the second resin layer indicates that there is no other layer between the polarizer layer and the second resin layer.

The second resin layer is formed of a second resin having a predetermined storage modulus. Thereby, the humidification reliability and the bending resilience of the polarizing film can be further enhanced.

[2. Polarizer layer]
As the polarizer layer, a film capable of transmitting one of two linearly polarized lights whose vibration directions intersect at right angles and absorbing or reflecting the other can be used. Here, the oscillation direction of the linearly polarized light indicates the oscillation direction of the electric field of the linearly polarized light. Such a film usually has a polarization transmission axis, can transmit linearly polarized light having a vibration direction parallel to the polarization transmission axis, and can absorb or reflect linearly polarized light having a vibration direction perpendicular to the polarization transmission axis.

Specific examples of the polarizer layer include a polyvinyl alcohol, a vinyl alcohol-based polymer such as a partially formalized polyvinyl alcohol, and a polyvinyl alcohol resin film, a dyeing treatment with a dichroic substance such as iodine and a dichroic dye. , Stretching treatment, cross-linking treatment and the like in an appropriate order and manner. The polarizer layer preferably contains a polyvinyl alcohol resin.

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 12 μm or less, more preferably 10 μm or less, and particularly preferably 7 μm or less. When the thickness of the polarizer layer is larger than the lower limit of the above range, the optical performance of the polarizing film can be sufficiently improved. When the thickness of the polarizer layer is equal to or less than the upper limit of the above range, the bending resilience of the polarizing film can be effectively improved.

[3. First resin layer]
The first resin layer is a layer formed of the first resin. The first resin has a storage elastic modulus measured as a film having a thickness of 1 mm within a predetermined range. Specifically, the storage elastic modulus of the first resin is usually 10 MPa or more, preferably 50 MPa or more, more preferably 150 MPa or more, and still more preferably 170 MPa or more, and usually 1000 MPa or less, preferably 900 MPa or less, more preferably Is 850 MPa or less. The above storage modulus of the first resin represents the storage modulus at 23 ° C., unless otherwise specified. By forming the first resin layer with the first resin having the storage elastic modulus in the above range, the humidification reliability and the bending resilience of the polarizing film can be improved.

The storage modulus of the first resin can be measured by the following measurement method.
The first resin is molded to prepare a measurement film having a thickness of 1 mm. As a molding method, a hot-melt pressing method can be used. Thereafter, the storage elastic modulus of the prepared measurement film is measured using a dynamic viscoelasticity measurement device. This measurement is performed in a temperature range of −100 ° C. to + 250 ° C., at a temperature rising rate of 5 ° C./min. From the measured results, the storage modulus at 23 ° C. can be read.

The first resin preferably has a water vapor permeability at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm in a predetermined range. Specifically, the water vapor transmission rate of the first resin is preferably 4.0 g / (m ² · day) or less, more preferably 3.0 g / (m ² · day) or less, and particularly preferably 2. 0 g / (m ² · day) or less. The lower limit is ideally not less than 0 g / (m ² · day), and may be not less than 0.1 g / (m ² · day). By forming the first resin layer with the first resin having the water vapor transmittance in the above range, the humidification reliability of the polarizing film can be particularly improved. Specifically, since the moisture permeability of the first resin layer can be sufficiently reduced, it is possible to suppress the water vapor from reaching the polarizer layer and effectively suppress the decrease in the degree of polarization due to the water vapor.

The water vapor transmission rate of the first resin can be measured by the following measurement method.
The first resin is molded to prepare a measurement film having a thickness of 100 μm. As a molding method, a hot-melt press method can be used. Thereafter, the prepared measurement film is measured for water vapor transmission rate under the conditions of a temperature of 40 ° C. and a humidity of 90% RH. This measurement is performed according to JIS K 7129B using a water vapor permeability measuring device.

The first resin usually contains a polymer. Examples of the polymer contained in the first resin include a polyester, an acrylic polymer, and a polymer having an alicyclic structure. One of these polymers may be used alone, or two or more thereof may be used in combination at an arbitrary ratio. Among them, a polymer having an alicyclic structure is preferable from the viewpoint of reducing the water vapor transmission rate of the first resin.

重合 A polymer having an alicyclic structure is a polymer in which the repeating unit of the polymer has an alicyclic structure. A polymer having an alicyclic structure usually has a low water vapor transmission rate. Therefore, by forming the first resin layer with the first resin containing the polymer having the alicyclic structure, it is possible to suppress the water vapor from reaching the polarizer layer and effectively improve the humidification reliability of the polarizing film. Can be improved.

The polymer having an alicyclic structure may have an alicyclic structure in the main chain, may have an alicyclic structure in the side chain, and may have an alicyclic structure in both the main chain and the side chain. It may have a formula structure. Above all, from the viewpoint of mechanical strength and heat resistance, a polymer having an alicyclic structure in at least the main chain is preferable.

Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure. Among them, from the viewpoint of mechanical strength and heat resistance, a cycloalkane structure and a cycloalkene structure are preferable, and a cycloalkane structure is particularly preferable.

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, particularly preferably, per one alicyclic structure. Is in the range of 15 or less. When the number of carbon atoms constituting the alicyclic structure is in this range, the mechanical strength, heat resistance and moldability of the resin containing the polymer having the alicyclic structure are highly balanced.

に お い て In the polymer having an alicyclic structure, the proportion of the repeating unit having an alicyclic structure can be appropriately selected depending on the purpose of use. The proportion of the repeating unit having an alicyclic structure in the polymer having an alicyclic structure 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 the repeating unit having the alicyclic structure in the polymer having the alicyclic structure is within this range, the transparency and heat resistance of the resin containing the polymer having the alicyclic structure are improved.

Examples of the polymer having an alicyclic structure include, for example, a norbornene-based polymer, a monocyclic cyclic olefin-based polymer, a cyclic conjugated diene-based polymer, a vinyl alicyclic hydrocarbon polymer, and a hydride thereof; And hydrides of vinyl aromatic hydrocarbon polymers. Among these, a hydride of a vinyl aromatic hydrocarbon polymer is preferable because it has good transparency and moldability, and further easily has a storage elastic modulus within a predetermined range.

The vinyl aromatic hydrocarbon polymer means a polymer containing a repeating unit [I] derived from an aromatic vinyl compound. Therefore, the hydride of a vinyl aromatic hydrocarbon polymer means a hydride of a polymer containing the repeating unit [I] derived from an aromatic vinyl compound. The repeating unit derived from a certain compound refers to a repeating unit having a structure obtained by polymerization of the compound. Further, a hydride of a polymer refers to a substance having a structure obtained by hydrogenation of the polymer. However, the repeating unit and the hydride are not limited by the production method.

Examples of the aromatic vinyl compound corresponding to the repeating unit [I] include styrene; α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4- Styrene having an alkyl group having 1 to 6 carbon atoms as a substituent, such as diisopropylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene; 4-chlorostyrene, dichlorostyrene, 4-mono Styrenes having a halogen atom as a substituent, such as fluorostyrene; styrenes having an alkoxy group having 1 to 6 carbon atoms as a substituent, such as 4-methoxystyrene; aryl groups as a substituent, such as 4-phenylstyrene Having styrene; vinyl naphthalenes such as 1-vinyl naphthalene and 2-vinyl naphthalene; etc. And the like. One of these may be used alone, or two or more may be used in combination at an arbitrary ratio. Among these, aromatic vinyl compounds not containing a polar group, such as styrene and styrenes having an alkyl group having 1 to 6 carbon atoms as substituents, are preferred because they can effectively reduce the hygroscopicity. Styrene is particularly preferred because of its ease of operation.

Among the hydrides of the polymer containing a repeating unit [I] derived from an aromatic vinyl compound, a polymer block [A] containing a repeating unit [I] derived from an aromatic vinyl compound as a main component and an aromatic vinyl compound A polymer block [B] containing a repeating unit [I] derived from a chain conjugated diene compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component. A block copolymer [D] composed of a polymer block [C] and a hydrogenated block copolymer [E] is preferable.
Among them, a polymer block [A] mainly composed of a repeating unit [I] derived from an aromatic vinyl compound and a polymer block [C] mainly composed of a repeating unit [II] derived from a chain conjugated diene compound. And a hydrogenated block copolymer [E] obtained by hydrogenating a block copolymer [D] consisting of
Here, the “main component” refers to a component that is usually 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, and particularly preferably 90% by weight or more in the polymer block.
By using the first resin containing the hydride [E] of the block copolymer, both the humidification reliability and the bending resilience of the polarizing film can be significantly improved.

In the block copolymer hydride [E], the ratio (wA / wB) of the weight fraction wA of the polymer block [A] to the weight fraction wB of the polymer block [B] is within a predetermined range. It is preferable to be within. In the hydride block copolymer [E], the ratio (wA / wC) of the weight fraction wA of the polymer block [A] to the weight fraction wC of the polymer block [C] is predetermined. Is preferably within the range. Specifically, the ratio (wA / wB) and the ratio (wA / wC) are preferably 30/70 or more, more preferably 40/60 or more, respectively, and preferably 70/30 or less, more preferably Is 60/40 or less. When the ratio (wA / wB) and the ratio (wA / wC) are equal to or larger than the lower limit of the above range, the hardness and heat resistance of the first resin layer can be improved, and birefringence can be reduced. When the ratio (wA / wB) and the ratio (wA / wC) are equal to or less than the upper limit of the above range, the flexibility of the first resin layer can be improved.

{Examples of the chain conjugated diene compound corresponding to the repeating unit [II] include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene and the like. One of these may be used alone, or two or more may be used in combination at an arbitrary ratio.

水 素 Hydride of a vinyl aromatic hydrocarbon polymer is a substance obtained by hydrogenating unsaturated bonds of a vinyl aromatic hydrocarbon polymer. Here, the unsaturated bonds of the vinyl aromatic hydrocarbon polymer to be hydrogenated include carbon-carbon unsaturated bonds in the main chain and side chains of the polymer, and carbon-carbon unsaturated bonds in the aromatic ring. Includes both. The hydrogenation rate is preferably at least 90%.

The hydrides of the vinyl aromatic hydrocarbon polymer are described in, for example, WO2000 / 32646, WO2001 / 081957, JP-A-2002-105151, JP-A-2006-195242, and JP-A-2006-195242. It can be produced by the method described in 2011-13378, International Publication WO2015 / 002020, and the like.

The weight average molecular weight Mw of the polymer contained in the first resin 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 It is 80,000 or less, particularly preferably 50,000 or less. When the weight average molecular weight is in such a range, the mechanical strength and moldability of the first resin layer are highly balanced.

The molecular weight distribution (Mw / Mn) of the polymer contained in the first resin is preferably 1.2 or more, more preferably 1.5 or more, particularly preferably 1.8 or more, and preferably 3.5 or less. It is more preferably at most 3.0, particularly preferably at most 2.7. Here, Mn represents a number average molecular weight. When the molecular weight distribution is at least the lower limit of the above range, the productivity of the polymer can be increased and the production cost can be suppressed. Further, when the molecular weight distribution is equal to or less than the upper limit of the above range, the amount of the low molecular component becomes small, so that the relaxation at the time of high temperature exposure can be suppressed, and the stability of the first resin layer can be increased.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) can be measured by using gel permeation chromatography (GPC). Examples of the solvent used in GPC include cyclohexane, toluene, and tetrahydrofuran. When GPC is used, the weight average molecular weight is measured, for example, as a relative molecular weight in terms of polyisoprene or polystyrene.

The first resin preferably further contains a plasticizer and / or a softener in combination with the polymer. The first resin may include only a plasticizer, may include only a softening agent, and may include both a plasticizer and a softening agent. When the first resin contains a plasticizer and / or a softening agent, the retardation of the first resin layer can be reduced.

As the plasticizer and the softener, those which can be uniformly dissolved or dispersed in the first resin can be used. Specific examples of the plasticizer and the softener include an ester plasticizer such as a polyhydric alcohol ester plasticizer and a polycarboxylic acid ester plasticizer; a phosphate ester plasticizer; a carbohydrate ester plasticizer; and other polymers. Softeners may be mentioned. The polyhydric alcohol ester plasticizer refers to an ester plasticizer composed of a polyhydric alcohol and a monovalent carboxylic acid. The polycarboxylic acid ester plasticizer refers to an ester plasticizer composed of a polycarboxylic acid and a monohydric alcohol.

Examples of the polyhydric alcohol which is a raw material of the ester-based plasticizer are not particularly limited, but ethylene glycol, glycerin, and trimethylolpropane are preferable.

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

例 Examples of the polycarboxylic acid ester plasticizer include dicarboxylic acid ester plasticizers and other polycarboxylic acid ester plasticizers.

Examples of the phosphoric acid ester plasticizer include alkyl phosphates such as triacetyl phosphate and tributyl phosphate; cycloalkyl phosphates such as tricyclobentyl phosphate and cyclohexyl phosphate; aryl phosphate esters such as triphenyl phosphate and tricresyl phosphate. Is mentioned.

As examples of the carbohydrate ester plasticizer, glucose pentaacetate, glucose pentapropionate, glucose pentabutyrate, saccharose octaacetate, saccharose octabenzoate and the like can be preferably mentioned, and among them, saccharose octaacetate is more preferable.

Examples of the polymer softener include an aliphatic hydrocarbon polymer, an alicyclic hydrocarbon polymer, polyethyl acrylate, polymethyl methacrylate, a copolymer of methyl methacrylate and 2-hydroxyethyl methacrylate, and methacryl. Acrylic polymers such as copolymers of methyl acrylate, methyl acrylate and 2-hydroxyethyl methacrylate; vinyl polymers such as polyvinyl isobutyl ether and poly N-vinylpyrrolidone; polystyrene and poly-4-hydroxystyrene Styrene-based polymers; polyesters such as polybutylene succinate, polyethylene terephthalate, and polyethylene naphthalate; polyethers such as polyethylene oxide and polypropylene oxide; polyamides, polyurethanes, and polyureas.

Specific examples of the aliphatic hydrocarbon polymer include low molecular weight substances such as polyisobutylene, polybutene, poly-4-methylpentene, poly-1-octene, and ethylene / α-olefin copolymer, and hydrogenated products thereof; polyisoprene; Examples include low molecular weight products such as polyisoprene-butadiene copolymer and hydrides thereof. The aliphatic hydrocarbon polymer preferably has a number average molecular weight of 300 to 5,000 from the viewpoint of easily dissolving or dispersing uniformly in the cycloolefin resin.

These polymer softeners may be a homopolymer composed of one kind of repeating unit or a copolymer having a plurality of repeating structures. In addition, one kind of the polymer softener may be used alone, or two or more kinds may be used in combination at an arbitrary ratio.

As the plasticizer and the softener, at least one selected from the group consisting of an ester-based plasticizer and an aliphatic hydrocarbon polymer is particularly preferable because it is particularly excellent in compatibility with the components contained in the first resin.

With respect to 100 parts by weight of the polymer contained in the first resin, the total amount of the plasticizer and the softener is preferably at least 5 parts by weight, more preferably at least 10 parts by weight, further preferably at least 20 parts by weight, It is preferably at most 100 parts by weight, more preferably at most 70 parts by weight, further preferably at most 50 parts by weight. When the total ratio of the plasticizer and the softener in the first resin is within the above range, the retardation of the first resin layer can be effectively reduced.

The first resin preferably further contains a moisture absorbent in combination with the polymer. When the first resin contains the moisture absorbent, the water vapor transmission rate can be reduced without impairing the transparency of the first resin. In particular, when the first resin layer is thin, the first resin preferably contains a moisture absorbent. For example, when the thickness of the first resin layer is 2 μm or less, it is particularly preferable that the first resin contains a moisture absorbent. As the hygroscopic agent, for example, zeolite, hydrotalcite and the like described in WO2018 / 155311, are preferable. One type of hygroscopic agent may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The amount of the hygroscopic agent is preferably at least 5 parts by weight, more preferably at least 10 parts by weight, particularly preferably at least 15 parts by weight, and preferably at least 40 parts by weight, based on 100 parts by weight of the polymer contained in the first resin. Parts by weight, more preferably 30 parts by weight or less, particularly preferably 25 parts by weight or less.

第一 From the viewpoint of uniformly dispersing the adsorbent in the resin, the first resin containing the desiccant preferably further contains a dispersant. As the dispersant, a compound having a skeleton capable of adsorbing to adsorbed particles such as a hygroscopic agent and a skeleton capable of interacting with a matrix such as a polymer and a solvent to improve the compatibility of the adsorbed particles can be used. The specific type of the adsorbent is not particularly limited. One type of dispersant may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The amount of the dispersant is preferably 20 parts by weight or more, more preferably 30 parts by weight or more, particularly preferably 40 parts by weight or more, and preferably 80 parts by weight or less, based on 100 parts by weight of the moisture absorbent. It is preferably at most 70 parts by weight, particularly preferably at most 60 parts by weight.

The first resin preferably further contains an organometallic compound in combination with the polymer. By containing the organometallic compound, the adhesion between the first resin layer and the polarizer layer can be increased.

The organometallic compound is a compound containing at least one of a chemical bond between metal and carbon and a chemical bond between metal and oxygen, and is a metal compound having an organic group. Examples of the organic metal compound include an organic silicon compound, an organic titanium compound, an organic aluminum compound, an organic zirconium compound, and the like. Of these, organosilicon compounds, organotitanium compounds and organozirconium compounds are preferred, and organosilicon compounds are more preferred because of their excellent reactivity with components such as polyvinyl alcohol contained in the polarizer layer. One type of organometallic compound may be used alone, or two or more types may be used in combination at an arbitrary ratio.

Examples of the organometallic compound include an organosilicon compound represented by the following formula (1).
R ¹ _a Si (OR ² ) _3-a (1)
(In the formula (1), R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an epoxy group, an amino group, a thiol group, an isocyanate group, Represents a group selected from the group consisting of organic groups having 1 to 10 atoms, and a represents an integer of 0 to 3.)

In the formula (1), preferred examples of R ¹ include an epoxy group, an amino group, a thiol group, an isocyanate group, a vinyl group, an acryl group, and an alkyl group having 1 to 8 carbon atoms.
In the formula (1), preferred examples of R ² include a hydrogen atom, a vinyl group, an aryl group, an acryl group, an alkyl group having 1 to 8 carbon atoms, —CH ₂ OC _n H _{2n + 1} (n is 1 Represents an integer of to 4).

Examples of the organosilicon compound include epoxy-based organosilicon compounds such as 3-glycidoxypropyltrimethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3-aminopropyltrimethoxysilane, N- Amino-based organosilicon compounds such as 2- (aminoethyl) -3-aminopropyltrimethoxysilane; isocyanurate-based organosilicon compounds such as tris- (trimethoxysilylpropyl) isocyanurate; 3-mercaptopropyltrimethoxysilane and the like Mercapto-based organosilicon compounds; isocyanate-based organosilicon compounds such as 3-isocyanatopropyltriethoxysilane;

Examples of the organic titanium compound include titanium alkoxide such as tetraisopropyl titanate, titanium chelate such as titanium acetylacetonate, and titanium acylate such as titanium isostearate.

Examples of the organic zirconium compound include zirconium alkoxides such as normal propyl zirconate, zirconium chelates such as zirconium tetraacetylacetonate, and zirconium acylates such as zirconium stearate.

Examples of the organoaluminum compound include aluminum alkoxides such as aluminum secondary butoxide and aluminum chelates such as aluminum trisacetylacetonate.

The amount of the organometallic compound is preferably at least 0.005 parts by weight, more preferably at least 0.01 parts by weight, particularly preferably at least 0.03 parts by weight, based on 100 parts by weight of the polymer contained in the first resin. And preferably 1.0 part by weight or less, more preferably 0.5 part by weight or less. When the ratio of the organometallic compound is in the above range, the adhesion between the first resin layer and the polarizer layer can be increased.

The first resin may further contain an arbitrary component in combination with the above-mentioned components. Examples of optional components include stabilizers such as antioxidants, ultraviolet absorbers, and light stabilizers; resin modifiers such as lubricants; coloring agents such as dyes and pigments; antistatic agents; One of these components may be used alone, or two or more thereof may be used in combination at an arbitrary ratio.

The glass transition temperature Tg of the first resin is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, particularly preferably 70 ° C. or higher, preferably 140 ° C. or lower, more preferably 120 ° C. or lower, particularly preferably 100 ° C. or lower. It is as follows. When the first resin has a plurality of glass transition temperatures, it is preferable that the highest glass transition temperature falls within the above range. When the glass transition temperature Tg of the first resin is in the above range, the balance between the adhesion between the first resin layer and the polarizer layer and the heat resistance of the polarizing film can be improved. The glass transition temperature Tg of the resin can be determined as the peak top value of tan δ in the viscoelastic spectrum.

The first resin is preferably transparent. Here, the transparent resin refers to a resin having a total light transmittance of usually 70% or more, preferably 80% or more, more preferably 90% or more, when the resin is measured as a test piece having a thickness of 1 mm. The total light transmittance can be measured in a wavelength range of 400 nm to 700 nm using an ultraviolet / visible spectrometer.

It is preferable that the first resin layer has excellent adhesion to the polarizer layer. Specifically, the adhesion of the first resin layer to the polarizer layer is preferably 0.5 N / 10 mm or more, more preferably 0.8 N / 10 mm or more, and particularly preferably 1.0 N / 10 mm or more. Thereby, the peeling between the polarizer layer and the first resin layer can be effectively suppressed, so that the humidification reliability and the bending resilience of the polarizing film can be effectively improved. The upper limit of the adhesion is not particularly limited, and it is most preferable that a measured value cannot be obtained due to material destruction.
The adhesion can be measured by using a peel tester and pulling the first resin layer in the direction of 180 ° with respect to the surface of the polarizer layer at a speed of 300 mm / min.

The first resin layer preferably has optical isotropic properties. The optically isotropic layer means a layer having an in-plane retardation Re of preferably 0 nm or more and 5 nm or less, more preferably 0 nm or more and 2 nm or less.

表面 The surface of the first resin layer opposite to the polarizer layer may be subjected to a surface treatment such as a corona treatment. When the surface treatment is performed, the adhesion between the first resin layer and an arbitrary layer such as an adhesive layer can be improved.

The thickness of the first resin layer is usually larger than 0 μm, preferably 1 μm or more, more preferably 2 μm or more, still more preferably 3 μm or more, preferably 13 μm or less, more preferably 10 μm or less, and still more preferably 7 μm or less. . When the thickness of the first resin layer is not less than the lower limit of the above range, the humidification reliability of the polarizing film can be effectively increased. In addition, when the thickness of the first resin layer is equal to or less than the upper limit of the above range, the bending resilience can be effectively exhibited.

The first resin layer can be formed by a forming method including, for example, a step of preparing a first resin liquid containing the first resin and a step of applying the first resin liquid to the polarizer layer.

The first resin liquid is a liquid material containing the first resin. This first resin liquid usually contains a first resin and a solvent. In the first resin liquid, some or all components of the first resin may be dissolved in a solvent. In the first resin liquid, a part or all of the components of the first resin may be dispersed in a solvent. Further, the first resin liquid may be in a heat-melted state containing no solvent.

As the solvent, an organic solvent is preferable, and an organic solvent that can dissolve the polymer contained in the first resin is particularly preferable. Examples of the solvent include a hydrocarbon solvent such as cyclohexane and toluene; a cyclic ether solvent such as tetrahydrofuran; One type of solvent may be used alone, or two or more types may be used in combination at an arbitrary ratio.

濃度 The concentration of the first resin in the first resin liquid may be arbitrarily set as long as the first resin liquid has a viscosity suitable for coating. A specific concentration range is preferably 15% by weight or more, more preferably 18% by weight or more, particularly preferably 20% by weight or more, preferably 35% by weight or less, more preferably 30% by weight or less, and particularly preferably. It is 28% by weight or less.

第一 By coating the first resin liquid on the surface of the polarizer layer, the first resin layer directly in contact with the polarizer layer can be obtained. Examples of coating methods include curtain coating, extrusion coating, roll coating, spin coating, dip coating, bar coating, spray coating, slide coating, print coating, gravure coating, and die coating. Method, gap coating method, dipping method and the like.

形成 The method of forming the first resin layer may further include an optional step in combination with the above steps. For example, the method of forming the first resin layer may include a step of drying the first resin liquid applied to the surface of the polarizer layer. Since the volatile components such as the solvent are removed by drying, the first resin layer can be formed by the first resin as the nonvolatile component of the first resin liquid.

[4. Second resin layer]
The polarizing film preferably includes, as an optional layer, a second resin layer directly in contact with the polarizer layer. The second resin layer is a layer formed of the second resin. The second resin has a storage modulus measured as a 1 mm thick film in the same predetermined range as the first resin. The above storage modulus of the second resin represents the storage modulus at 23 ° C., unless otherwise specified. By forming the second resin layer with the second resin having the storage elastic modulus in the above range, the humidification reliability and the bending resilience of the polarizing film can be particularly improved. The storage modulus measured as a 1 mm thick film of the first resin and the storage modulus measured as a 1 mm thick film of the second resin may be the same value or different.
The storage modulus of the second resin can be measured by the same method as that for the first resin.

The second resin preferably has a water vapor permeability at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm in the same predetermined range as the first resin. By forming the second resin layer with the second resin having the water vapor transmittance in the above range, the humidification reliability of the polarizing film can be particularly improved. The water vapor transmission rate at 40 ° C. and 90% RH when the first resin is measured as a 100 μm thick film is the same as the water vapor transmission rate at 40 ° C. and 90% RH when the second resin is measured as a 100 μm thick film. It may be a value or it may be different.
The water vapor transmission rate of the second resin can be measured by the same method as that for the first resin.

樹脂 As the second resin, any resin within the range described as the first resin can be used. Therefore, the composition (type and amount) of the component contained in the second resin can be arbitrarily adopted from the range described as the composition of the component contained in the first resin. Further, the physical properties such as the glass transition temperature and the transparency of the second resin are preferably within the ranges described as the physical properties of the first resin. Thereby, the advantages described in the description of the first resin layer can be obtained also in the second resin layer. The composition and the physical properties of the first resin and the composition and the physical properties of the second resin may be the same or different.

The second resin layer preferably has excellent adhesion to the polarizer layer. Specifically, the adhesion of the second resin layer to the polarizer layer is preferably in the same range as that described for the adhesion of the first resin layer to the polarizer layer. Thereby, the peeling of the polarizer layer and the second resin layer can be effectively suppressed, so that the humidification reliability and the bending resilience of the polarizing film can be effectively improved.
The adhesion of the second resin layer to the polarizer layer can be measured by the same method as the adhesion of the first resin layer to the polarizer layer.

The second resin layer preferably has optical isotropic properties.

(4) The surface of the second resin layer opposite to the polarizer layer may be subjected to a surface treatment such as a corona treatment. When the surface treatment is performed, the adhesion between the second resin layer and an arbitrary layer such as an adhesive layer can be improved.

厚 み The thickness of the second resin layer can be arbitrarily adopted from the range described as the thickness of the first resin layer. Thereby, the advantages described in the description of the first resin layer can be obtained also in the second resin layer. The thickness of the first resin layer and the thickness of the second resin layer may be the same or different.

The second resin layer can be formed by the same forming method as the first resin layer. Therefore, the second resin layer can be formed by a forming method including, for example, a step of preparing a second resin liquid containing the second resin and a step of applying the second resin liquid to the polarizer layer. The second resin liquid may include a solvent as in the first resin liquid. The method for forming the second resin layer may include an optional step. For example, the method of forming the second resin layer may include a step of drying the second resin liquid applied to the surface of the polarizer layer.

[5. Adhesive layer]
The polarizing film may further include an adhesive layer as an optional layer. In this case, the polarizing film preferably includes a polarizer layer, a first resin layer, and an adhesive layer in this order. By utilizing the adhesive strength of the adhesive layer, the polarizing film can be bonded to another optical member. For example, when a polarizing film is incorporated in a display device having a display element such as a liquid crystal cell and an organic EL element, an adhesive layer of the polarizing film is attached to the display element.

粘着 Examples of the pressure-sensitive adhesive as a material of the pressure-sensitive adhesive layer include pressure-sensitive adhesives such as a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a polyvinyl ether-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, and a polyolefin-based pressure-sensitive adhesive. Above all, acrylic pressure-sensitive adhesives and polyolefin-based pressure-sensitive adhesives are preferable from the viewpoint of heat resistance and productivity, and acrylic pressure-sensitive adhesives are particularly preferable. Further, one kind of the adhesive may be used alone, or two or more kinds may be used in combination at an arbitrary ratio.

厚 み The thickness of the adhesive layer is preferably 2.0 µm or more, more preferably 5.0 µm or more, preferably 25.0 µm or less, more preferably 20.0 µm or less, and particularly preferably 15.0 µm or less. When the thickness of the adhesive layer is equal to or more than the lower limit of the above range, the adhesive strength of the adhesive layer can be increased, and the entrapment of air bubbles during bonding can be suppressed. When the thickness of the pressure-sensitive adhesive layer is equal to or less than the upper limit of the above range, the expansion and contraction behavior of the polarizing film can be suppressed, and the bezel can be made free.

[6. Protective film layer]
The polarizing film may further include a protective film layer as an optional layer. In this case, the polarizing film preferably includes a first resin layer, a polarizer layer, and a protective film layer in this order. Thereby, not only the first resin layer but also the protective film layer can protect the polarizer layer. It is also useful to provide the protective film layer, the second resin layer, the polarizer layer, and the first resin layer in this order. In this case, in addition to the humidification reliability of the polarizing film, pencil hardness and scratch resistance Can be increased. A clear hard coat layer, an anti-glare hard coat layer, an antireflection layer, an antistatic layer, and an antifouling layer may be added to the protective film layer alone, or a plurality of them may be added in combination.

樹脂 A resin film formed of a transparent resin is usually used as the protective film layer. Examples of the resin contained in the protective film layer include, as examples having excellent transparency, mechanical strength, heat stability and moisture shielding properties, acetate resins such as triacetyl cellulose, polyester resins, polyether sulfone resins, polycarbonate resins, and polyamide resins. , A polyimide resin, a polyolefin resin, a cyclic olefin resin, a (meth) acrylic resin, and the like. Among them, an acetate resin, a cyclic olefin resin, and a (meth) acrylic resin are preferable in terms of low birefringence, and a cyclic olefin resin is particularly preferable from the viewpoints of transparency, low moisture absorption, dimensional stability, light weight, and the like.

厚 み The thickness of the protective film layer is not particularly limited, and may be, for example, 20 μm to 100 μm.

[7. Adhesive layer]
The polarizing film may further include an adhesive layer as an optional layer. The layers included in the polarizing film can be bonded to each other by the adhesive layer. For example, the polarizer layer and the protective film layer can be bonded by an adhesive layer.

Examples of the adhesive as a material of the adhesive layer include, for example, an acrylic adhesive, an epoxy adhesive, a urethane adhesive, a polyester adhesive, a polyvinyl alcohol adhesive, a polyolefin adhesive, a modified polyolefin adhesive, Ethylene adhesives such as polyvinyl alkyl ether adhesives, rubber adhesives, vinyl chloride-vinyl acetate adhesives, SEBS (styrene-ethylene-butylene-styrene copolymer) adhesives, and ethylene-styrene copolymers And acrylate-based adhesives such as ethylene-methyl (meth) acrylate copolymer and ethylene-ethyl (meth) acrylate copolymer.

(4) The thickness of the adhesive layer is usually larger than 0 μm, preferably 0.1 μm or more, more preferably 1 μm or more, preferably 5 μm or less, more preferably 3 μm or less. When the thickness of the adhesive layer is in the above range, a good appearance can be obtained, and the layers included in the polarizing film can be strongly bonded to each other.

[8. Other layers]
The polarizing film may have an optically anisotropic layer as an optional layer. For example, a polarizing film to be applied to a liquid crystal display device has an optically anisotropic film for compensating the viewing angle dependence of the liquid crystal contained in the liquid crystal cell and for compensating the axis shift of the polarizer layer. It may be provided as a layer. Further, for example, a polarizing film applied to a liquid crystal display device may include a λ / 4 layer as an optically anisotropic layer in combination with an optical compensation film layer in order to realize a reflection suppressing function. The organic EL display device does not usually require a polarizing film for emitting light of RGB and displaying an image. However, by applying a polarizing film having a λ / 4 layer as an optically anisotropic layer, a black display characteristic can be obtained. Quality can be improved.

Λ / 4 layer refers to a layer having a predetermined range of in-plane retardation 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, preferably 165 nm or less, more preferably 155 nm or less, particularly Preferably it is 150 nm or less.

From the viewpoint of viewing angle characteristics, it is preferable that the three-dimensional refractive index of the λ / 4 layer exhibit uniaxiality such that nx> ny = nz. Further, the three-dimensional refractive index of the λ / 4 layer may preferably satisfy nx> nz> ny, and ideally, the relationship of (nx−nz) / (nx−ny) = 0.5 is satisfied.

The slow axis of the λ / 4 layer is preferably 45 ° ± 5 ° (ie, 40 ° to 50 °), more preferably 45 ° ± 3 ° (ie, 42 ° to 50 °) with respect to the polarization transmission axis of the polarizer layer. 48 °), and particularly preferably an angle of 45 ° ± 1 ° (ie, 44 ° to 46 °). Thereby, a circularly polarizing plate can be obtained as a combination of the polarizer layer and the λ / 4 layer.

The λ / 4 layer preferably has reverse wavelength dispersion characteristics. The inverse wavelength dispersion property refers to a property in which in-plane retardation Re (450) and Re (550) at measurement wavelengths 450 nm and 550 nm satisfy Re (450) <Re (550). The λ / 4 layer having the inverse wavelength dispersion characteristic can exert its optical function in a wide wavelength range.

The λ / 4 layer may be manufactured, for example, as a stretched film obtained by stretching a film before stretching formed of a suitable resin. The λ / 4 layer is, for example, a liquid crystal composition layer containing an appropriate liquid crystal compound, and after the molecules of the liquid crystal compound are aligned, the liquid crystal composition is cured to form a liquid crystal cured layer. It may be manufactured. Above all, from the viewpoint of obtaining a thin and flexible polarizing film, the λ / 4 layer is preferably a liquid crystal cured layer. The λ / 4 layer as such a liquid crystal cured layer can be manufactured by, for example, a method described in International Publication WO2016 / 121602.

The polarizing film may further include a λ / 2 layer as an optional layer. The λ / 2 layer refers to a layer having a predetermined range of in-plane retardation at a wavelength of 550 nm. Specifically, the in-plane retardation of the λ / 2 layer at a wavelength of 550 nm is preferably 240 nm or more, more preferably 250 nm or more, preferably 300 nm or less, more preferably 280 nm or less, and particularly preferably 265 nm or less. .

From the viewpoint of viewing angle characteristics, it is preferable that the three-dimensional refractive index of the λ / 2 layer exhibit uniaxiality such that nx> ny = nz. Further, the three-dimensional refractive index of the λ / 2 layer is preferably nx> nz> ny, and ideally, the relationship of (nx−nz) / (nx−ny) = 0.5 is satisfied.

The slow axis of the λ / 2 layer may be arbitrarily set according to the optical function desired to be exhibited by the polarizing film. For example, when the polarizing film includes a combination of a λ / 2 layer and a λ / 4 layer, the angle θ (λ / 4) formed by the slow axis of the λ / 4 layer with respect to a certain reference direction, On the other hand, when the angle θ (λ / 2) formed by the λ / 2 layer satisfies the formula (X): “θ (λ / 4) = 2θ (λ / 2) + 45 °”, the λ / 2 layer and λ The combination of / 4 layers is such that a wide band λ / which can give in-plane retardation of approximately ４ wavelength of the light to the light in the front direction passing through the λ / 2 layer and the λ / 4 layer in a wide wavelength range. It can function as four plates (see JP-A-2007-004120). Therefore, when trying to obtain a polarizing film that can function as a circularly polarizing plate in a wide wavelength range, the slow axes of the λ / 2 layer and the λ / 4 layer are set so as to satisfy the relationship close to the above-described formula (X). Is preferred. For example, it is preferable that the slow axes of the λ / 2 layer and the λ / 4 layer satisfy any of the following relationships (X1) to (X3).

(X1) The angle formed by the slow axis of one of the λ / 4 layer and the λ / 2 layer with respect to the polarization transmission axis of the polarizer layer is preferably 75 ° ± 5 ° (ie, 70 ° to 80 °), It is preferably 75 ° ± 3 ° (ie, 72 ° to 78 °), particularly preferably 75 ° ± 1 ° (ie, 74 ° to 76 °), and the other delay of the λ / 4 layer and the λ / 2 layer. The angle between the phase axis and the polarization transmission axis of the polarizer layer is preferably 15 ° ± 5 ° (ie, 10 ° to 20 °), more preferably 15 ° ± 3 ° (ie, 12 ° to 18 °); Particularly preferably, it is 15 ° ± 1 ° (that is, 14 ° to 16 °).

(X2) The angle formed by the slow axis of one of the λ / 4 layer and the λ / 2 layer with respect to the polarization transmission axis of the polarizer layer is preferably 15 ° ± 5 ° (ie, 10 ° to 20 °), and It is preferably 15 ° ± 3 ° (ie, 12 ° to 18 °), particularly preferably 15 ° ± 1 ° (ie, 14 ° to 16 °), and the other delay of the λ / 4 layer and the λ / 2 layer. The angle between the phase axis and the polarization transmission axis of the polarizer layer is preferably 75 ° ± 5 ° (ie, 70 ° to 80 °), more preferably 75 ° ± 3 ° (ie, 72 ° to 78 °); Particularly preferably, it is 75 ° ± 1 ° (that is, 74 ° to 76 °).

(X3) The angle formed by the slow axis of one of the λ / 4 layer and the λ / 2 layer with respect to the polarization transmission axis of the polarizer layer is preferably 22.5 ° ± 5 ° (that is, 17.5 ° to 27 °). 0.5 °), more preferably 22.5 ° ± 3 ° (ie, 19.5 ° to 25.5 °), and particularly preferably 22.5 ° ± 1 ° (ie, 21.5 ° to 23.5 °). And the angle formed by the other slow axis of the λ / 4 layer and the λ / 2 layer with respect to the polarization transmission axis of the polarizer layer is preferably 90 ° ± 5 ° (that is, 85 ° to 95 °). More preferably 90 ° ± 3 ° (ie, 87 ° -93 °), and particularly preferably 90 ° ± 1 ° (ie, 89 ° -91 °).

Here, the direction in which the slow axis of one of the λ / 4 layer and the λ / 2 layer forms the above angle with the polarization transmission axis of the polarizer layer is usually the other of the λ / 4 layer and the λ / 2 layer. Is the same as the direction in which the slow axis forms the above-mentioned angle with respect to the polarization transmission axis of the polarizer layer.

The λ / 2 layer preferably has reverse wavelength dispersion characteristics. The λ / 2 layer having the inverse wavelength dispersion characteristic can exhibit its optical function in a wide wavelength range.

The λ / 2 layer may be manufactured, for example, as a stretched film. The λ / 2 layer may be manufactured as a liquid crystal cured layer, for example. Among them, from the viewpoint of obtaining a thin and flexible polarizing film, the λ / 2 layer is preferably a liquid crystal cured layer. Such a λ / 2 layer as a liquid crystal cured layer can be produced, for example, by the method described in International Publication WO2016 / 121602.

The polarizing film may further include a positive C plate layer as an optional layer. In particular, when the polarizing film does not include a λ / 4 layer or a λ / 2 layer having a three-dimensional refractive index satisfying the relationship of (nx−nz) / (nx−ny) = 0.5, the polarizing film becomes positive. It is preferable to provide a C plate layer. The positive C plate layer is a layer that functions as a positive C plate. Even if the polarizing film does not include a λ / 4 layer or a λ / 2 layer having a three-dimensional refractive index satisfying the relationship of (nx−nz) / (nx−ny) = 0.5, there is a positive C plate layer. Thereby, the refractive index in the thickness direction can be appropriately adjusted, and the viewing angle characteristics can be improved. Further, a plurality of positive C plate layers may be used in combination with the above-described optically anisotropic layers such as the λ / 2 layer and the λ / 4 layer.

The positive C plate layer may be manufactured, for example, as a stretched film. Further, the positive C plate layer may be manufactured, for example, as a liquid crystal cured layer. Above all, from the viewpoint of obtaining a thin and flexible polarizing film, the positive C plate layer is preferably a liquid crystal cured layer. Such a positive C-plate layer as a liquid crystal cured layer can be manufactured by a method described in, for example, JP-A-2015-14712, JP-A-2015-57646, and the like. Further, as the liquid crystal compound for producing the positive C plate layer, a compound having reverse wavelength dispersion characteristics may be used.

任意 The above-mentioned arbitrary layers may be used alone or in combination of two or more. Further, the number of the above-mentioned layers may be one, or two or more. Furthermore, the positions of the above-mentioned layers are arbitrary as long as the effects of the present invention are not significantly impaired.

[9. Method for producing polarizing film]
The polarizing film can be manufactured by a manufacturing method including a step of forming a first resin layer on a polarizer layer. Therefore, the polarizing film can be manufactured by, for example, a manufacturing method including a step of preparing a first resin liquid containing the first resin and a step of applying the first resin liquid to the polarizer layer. Further, the polarizing film including the second resin layer, for example, a step of preparing a first resin liquid containing a first resin, a step of applying a first resin liquid to the polarizer layer, a second resin containing a second resin It can be manufactured by a manufacturing method including a step of preparing two resin liquids and a step of applying a second resin liquid to the polarizer layer. At this time, either the first resin layer or the second resin layer may be formed first, or both may be formed simultaneously. Further, the method for producing a polarizing film may further include an optional step.

[10. Example of Layer Structure of Polarizing Film]
Hereinafter, preferred layer configurations of the polarizing film will be described with reference to the drawings.

FIG. 1 is a schematic sectional view of a polarizing film 100 as a first example of the present invention. As shown in FIG. 1, the polarizing film 100 according to this example includes an adhesive layer 110, a first resin layer 120, a polarizer layer 130, an adhesive layer 140, and a protective film layer 150 in this order. When this polarizing film 100 is provided in a display device (not shown), usually, the adhesive layer 110 is provided on the display element side, and the protective film layer 150 is provided on the viewing side.

FIG. 2 is a schematic sectional view of a polarizing film 200 as a second example of the present invention. As shown in FIG. 2, the polarizing film 200 according to this example includes an adhesive layer 110, a first resin layer 120, a polarizer layer 130, and a second resin layer 260 in this order. When this polarizing film 200 is provided in a display device (not shown), usually, the adhesive layer 110 is provided on the display element side, and the second resin layer 260 is provided on the viewing side.

In the polarizing films 100 and 200 according to any of the above-described examples, the polarizer layer 130 is effectively protected from water vapor, so that a decrease in the degree of polarization due to water vapor can be suppressed, and thus excellent humidification reliability can be obtained. Can be. Further, since the first resin layer 120 and the second resin layer 260 have high flexibility, excellent bending restorability can be obtained.

Hereinafter, the present invention will be described specifically with reference to examples. However, the present invention is not limited to the embodiments described below, and may be arbitrarily modified and implemented without departing from the scope of the claims of the present invention and equivalents thereof.

に お い て In the following description, “%” and “parts” indicating amounts are based on weight unless otherwise specified. The operations described below were performed in a normal temperature and normal pressure atmosphere unless otherwise specified.

In the following description, a repeating unit derived from styrene may be represented by an abbreviation “St”, and a polymer block formed by a repeating unit derived from styrene may be represented by an “St block”.
In the following description, a repeating unit derived from isoprene may be represented by an abbreviation “IP”, and a polymer block formed by a repeating unit derived from isoprene may be represented by an “IP block”.
In the following description, a random polymerization block formed of a repeating unit derived from styrene and a repeating unit derived from isoprene may be represented by “St-IP block”.

[Evaluation method]
[Method of measuring weight average molecular weight Mw and number average molecular weight Mn of polymer]
The weight average molecular weight Mw and the number average molecular weight Mn of the polymer were measured as a polystyrene equivalent or a polyisoprene equivalent using a gel permeation chromatography (GPC) system (“HLC8020GPC” manufactured by Tosoh Corporation). When polystyrene was used as the standard substance, tetrahydrofuran was used as the solvent. When polyisoprene was used as a standard substance, cyclohexane was used as a solvent. The temperature during the measurement was 38 ° C.

(Method of measuring hydrogenation rate of polymer)
The hydrogenation rate of the polymer was measured by ¹ H-NMR measurement.

[Thickness measurement method]
The thickness of the film was measured with a snap gauge.

(Measurement method of storage modulus)
The storage elastic modulus is measured by a dynamic viscoelasticity measuring device (“ARES” manufactured by TA Instruments Japan) at a temperature rising rate of 5 ° C./min in a temperature range of −100 ° C. to + 250 ° C. did. From the measured result, the storage modulus at 23 ° C. was read.

(Method of measuring water vapor transmission rate)
The water vapor transmission rate was measured using a water vapor transmission rate measuring device (“PERMATRAN-W” manufactured by MOCON) under the conditions of a temperature of 40 ° C. and a humidity of 90% RH according to JIS K 7129 B method.

[Evaluation method of humidification reliability of polarizing film]
The evaluation sample was obtained by bonding the adhesive layer of the polarizing film to a glass plate. The evaluation sample was subjected to a humidification test in which the sample was allowed to stand for 500 hours in an environment at a temperature of 60 ° C. and a humidity of 90% RH. Using the evaluation sample after the test, the degree of polarization of the polarizing film was measured. As a measuring device, an ultraviolet-visible spectrophotometer (“V7100” manufactured by JASCO Corporation) was used.
From the obtained degree of polarization, the humidification reliability of the polarizing film was evaluated based on the following criteria.
Judgment criteria AA: degree of polarization of 99.95% or more.
A: The degree of polarization is 99.90% or more and less than 99.95%.
B: The degree of polarization is 99.00% or more and less than 99.90%.
C: The degree of polarization is less than 99.00%.

(Evaluation method of bending resilience of polarizing film)
The polarizing film was bent with a mandrel having a diameter of 2 mm in accordance with JIS K5600-5-1 (flexible cylindrical mandrel method). At this time, the polarizing film was bent such that the surface on the side opposite to the adhesive layer (that is, the surface on the side of the protective film or the side of the second resin layer) was inside the mandrel. This folded state was maintained for 24 hours. Thereafter, the polarizing film was removed from the mandrel and spread on a horizontal table. The bent portion bent by the mandrel was visually observed. The distortion of the bent portion was evaluated from the observed reflected light at the bent portion. Then, based on the distortion of the bent portion, the bending resilience of the polarizing film was evaluated based on the following criteria.
Criterion AA: The bent portion has no distortion and is completely restored.
A: The bent portion is slightly restored without any distortion.
B: The distortion of the bent portion is remarkable, and it has not been restored.

[Production Example 1. Production and evaluation of resin X1]
(Synthesis of block copolymer)
After the stainless steel reactor equipped with a stirrer was sufficiently dried, the reactor was replaced with nitrogen.
To this reactor, 320 parts of dehydrated cyclohexane, 25.0 parts of styrene monomer, and 0.38 part of dibutyl ether were charged to obtain a reaction solution. While stirring the reaction solution at 60 ° C., 0.36 parts of an n-butyllithium solution (a 15% hexane solution) was added to initiate the first-stage polymerization reaction.
After performing the polymerization reaction for 1 hour, 50.0 parts of a mixed monomer composed of 25.0 parts of a styrene monomer and 25.0 parts of an isoprene monomer are added to the reaction solution, and the polymerization reaction in the second stage is further performed for 1 hour. went.
Thereafter, 25.0 parts of a styrene monomer was added to the reaction solution, and the third-stage polymerization reaction was further performed for 1 hour.
Thereafter, 0.2 parts of isopropyl alcohol was added to the reaction solution to stop the reaction. Thus, a block copolymer having a structure of styrene block / styrene-isoprene random copolymer block / styrene block was obtained in the reaction solution.

(Hydrogenation of block copolymer)
Next, the reaction solution was transferred to a pressure-resistant reactor equipped with a stirrer. To this pressure-resistant reactor, 10 parts of a silica-alumina-supported nickel catalyst (“E22U” manufactured by JGC Corporation, nickel supported amount 60%) as a hydrogenation catalyst was added and mixed. Further, the inside of the reactor was replaced with hydrogen gas. Thereafter, hydrogen was supplied to the reactor while stirring the reaction solution, and a hydrogenation reaction was performed at a temperature of 160 ° C. and a pressure of 4.5 MPa for 8 hours.
After the completion of the hydrogenation reaction, the reaction solution was filtered to remove the hydrogenation catalyst. Thereafter, the reaction solution was diluted by adding 800 parts of cyclohexane. The diluted reaction solution was poured into 3500 parts of isopropanol to precipitate a hydride of the block copolymer. As the above-mentioned isopropanol, what was filtered with a filter having a pore size of 1 μm in a class 1000 clean room was used.
The hydride of the precipitated block copolymer was separated and collected by filtration, and dried under reduced pressure at 80 ° C. for 48 hours.

The obtained hydride of the block copolymer is a hydride of a ternary block copolymer composed of St block, St-IP block and St block, and the molar ratio of each block is St block / St- IP block / St block = 25/50 (St: IP = 25: 25) / 25. This hydride had a weight average molecular weight Mw of 85,000, a molecular weight distribution Mw / Mn of 1.44, and a hydrogenation rate of the main chain and the aromatic ring of almost 100%.

(Preparation of resin X1)
Pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] ("Songnox 1010 manufactured by Matsubara Sangyo Co., Ltd.) was added to 100 parts of the hydride of the above block copolymer as an antioxidant. ") 0.1 part was melt-kneaded to obtain resin X1. This resin X1 was formed into a pellet and collected.

(Measurement of storage modulus)
The resin X1 was hot-melted using a hot-melt pressing machine under the conditions of a clearance of 1 mm, a temperature of 250 ° C., and a pressure of 30 MPa to form a 1-mm-thick measurement film. Using this measurement film, the storage elastic modulus of the resin X1 was measured by the above-described measurement method. The storage elastic modulus of the resin X1 measured at a thickness of 1 mm was 520 MPa.

(Method of measuring water vapor transmission rate)
The resin X1 was hot-melted using a hot-melt pressing machine under the conditions of a clearance of 100 μm, a temperature of 250 ° C., and a pressure of 30 MPa to form a measurement film having a thickness of 100 μm. Using this film for measurement, the water vapor transmission rate of the resin X1 was measured by the above-described measurement method. The water vapor transmission rate of the resin X1 measured at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm was 2.0 g / (m ² · day).

[Production Example 2. Production and evaluation of resin X2]
The charged amount of the styrene monomer in the first stage polymerization reaction was changed to 30.0 parts.
The charged amounts of the styrene monomer and the isoprene monomer in the second stage polymerization reaction were changed to 20.0 parts and 20.0 parts.
The amount of the styrene monomer charged in the third stage polymerization reaction was changed to 30.0 parts.
Except for the above, the production and evaluation of the resin X2 were performed by the same operation as in Production Example 1.

The hydride of the block copolymer contained in the resin X2 is a hydride of a ternary block copolymer composed of St block, St-IP block, and St block, and the molar ratio of each block is St block / St-IP block / St block = 30/40 (St: IP = 20: 20) / 30. This hydride had a weight average molecular weight Mw of 80,000, a molecular weight distribution Mw / Mn of 1.47, and a hydrogenation ratio of the main chain and the aromatic ring of almost 100%.
In addition, the storage elastic modulus of the resin X2 measured as a film having a thickness of 1 mm was 780 MPa.
Further, the water vapor transmission rate of the resin X2 at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm was 2.0 g / (m ² · day).

[Production Example 3. Production and evaluation of resin X3]
100 parts of resin X1 produced in Production Example 1 and 30 parts of polyisobutene (“Nisseki Polybutene HV-300” manufactured by JX Nippon Oil & Energy Co., number average molecular weight 1,400) as a softening agent were melt-kneaded, Resin X3 was obtained.

For the resin X3, the storage elastic modulus and the water vapor transmission rate were evaluated by the same method as the evaluation method of the resin X1 in Production Example 1.
The storage elastic modulus of the resin X3 measured as a film having a thickness of 1 mm was 430 MPa.
The water vapor transmission rate of the resin X3 measured at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm was 3.0 g / (m ² · day).

[Production Example 4. Production and Evaluation of Resin X4]
In the second stage polymerization reaction, 50 parts of isoprene monomer was charged instead of 25.0 parts of styrene monomer and 25.0 parts of isoprene monomer.
Except for the above, the production and evaluation of Resin X4 were performed by the same operations as in Production Example 1.

The hydride of the block copolymer contained in the resin X4 is a hydride of a ternary block copolymer composed of an St block, an IP block, and an St block, and the molar ratio of each block is St block / IP block. / St block = 25/50/25. This hydride had a weight average molecular weight Mw of 68,000, a molecular weight distribution Mw / Mn of 1.21, and a hydrogenation rate of the main chain and the aromatic ring of almost 100%.
The storage elastic modulus of the resin X4 measured as a 1-mm thick film was 210 MPa.
Furthermore, the water vapor transmission rate of the resin X4 at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm was 4.0 g / (m ² · day).

[Production Example 5. Production and evaluation of resin X5]
100 parts of cyclohexane, 5 parts of zeolite particles (primary particle diameter 50 nm, refractive index 1.5) as a hygroscopic agent, and 2 parts of a dispersant ("DISPERBYK-109" manufactured by BYK) were stirred using a bead mill. After mixing, a zeolite dispersion was obtained.
This zeolite dispersion, the resin X4 produced in Production Example 4, and cyclohexane were mixed to obtain a resin solution containing the resin X4 at a concentration of 25% by weight. The amount of the zeolite dispersion was adjusted so that the amount of zeolite particles was 19% by weight based on 100% by weight of the resin X4.

Cyclohexane as a solvent was removed from the resin solution by drying to obtain a resin X4, a resin X5 as a composition containing zeolite particles and a dispersant. For this resin X5, the storage elastic modulus and the water vapor transmission rate were evaluated by the same method as the evaluation method of the resin X1 in Production Example 1.
The storage elastic modulus of the resin X5 measured as a film having a thickness of 1 mm was 220 MPa.
The water vapor transmission rate of the resin X5 at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm was 0.8 g / (m ² · day).

[Example 1]
(1-1. Production of Polarizer Layer)
An unstretched polyvinyl alcohol film having a thickness of 20 μm (vinylon film, average degree of polymerization of about 2400, degree of saponification of 99.9 mol%) was prepared as a long raw film. While continuously transporting the film in the longitudinal direction via a guide roll, the film is subjected to a swelling treatment in which the film is immersed in pure water at 30 ° C. for 1 minute, and a dyeing solution (iodine and potassium iodide in a molar ratio of 1:23). (Dye solution containing 1.2 mmol / L of dye solution) at 32 ° C. for 2 minutes to perform a dyeing treatment to adsorb iodine on the film. Thereafter, the film was washed with a 3% aqueous solution of boric acid at 35 ° C. for 30 seconds. Thereafter, the film was stretched 6.0 times at 57 ° C. in an aqueous solution containing 3% of boric acid and 5% of potassium iodide. Thereafter, the film was subjected to a complementary color treatment at 35 ° C. in an aqueous solution containing 5% of potassium iodide and 1.0% of boric acid. Thereafter, the film was dried at 60 ° C. for 2 minutes to obtain a polarizer layer having a thickness of 7 μm. The degree of polarization of this polarizer layer was measured with an ultraviolet-visible spectrophotometer (“V-7100”, manufactured by JASCO Corporation) and found to be 99.996%.

(1-2. Lamination of protective film layer to polarizer layer)
Acrylic resin (“SUMIPEX HT55X” manufactured by Sumitomo Chemical Co., Ltd.) was supplied to a hot melt extruded film forming machine equipped with a T die. The acrylic resin was extruded from the T-die, and the acrylic resin was formed into a film. Thus, a long protective film layer formed of an acrylic resin and having a thickness of 40 μm was obtained.

One surface of the obtained protective film layer was subjected to a corona treatment. Thereafter, an ultraviolet-curing adhesive ("Arcles KRX-7007" manufactured by ADEKA) was applied to the surface of the protective film layer subjected to the corona treatment to form an adhesive layer. The polarizer layer and the protective film layer were bonded via the adhesive layer using a pinch roll. Immediately thereafter, the adhesive layer was irradiated with ultraviolet light of 750 mJ / cm ² by a UV irradiation device to cure the adhesive layer. Thus, an intermediate film having a layer structure of polarizer layer / adhesive layer (thickness: 2 μm) / protective film layer was obtained.

(1-3. Formation of resin layer)
The resin X1 produced in Production Example 1 was mixed with cyclohexane as a solvent to obtain a resin solution as a first resin liquid containing the resin X1 at a concentration of 25% by weight. This resin solution was applied to the surface of the polarizer layer of the intermediate film, and then dried at 70 ° C. for 2 minutes to obtain a 4 μm-thick first resin layer formed of the resin X1. As a result, a multilayer film having a layer structure of first resin layer / polarizer layer / adhesive layer (2 μm thickness) / protective film layer was obtained.

(1-4. Formation of adhesive layer)
69 parts by weight of n-butyl acrylate, 30 parts by weight of phenoxydiethylene glycol acrylate, 1 part by weight of 4-hydroxybutyl acrylate, 120 parts by weight of ethyl acetate and 0.1 part by weight of azobisisobutyronitrile were placed in a reaction vessel. The air in the reaction vessel was replaced with nitrogen gas. Thereafter, the reaction solution was heated to 66 ° C. in a nitrogen atmosphere under stirring and reacted for 10 hours. After completion of the reaction, the reaction solution was diluted with ethyl acetate to obtain an acrylic copolymer solution having a solid content of 20% by weight. When the obtained acrylic copolymer was analyzed by GPC, its weight average molecular weight (Mw) was 1.1 million.

Based on 500 parts by weight of the acrylic copolymer solution (100 parts by weight of solid content), 0.1 part by weight of an isocyanate-based crosslinking agent (“Coronate L” manufactured by Nippon Polyurethane Co.) and a silane coupling agent (“KBM” manufactured by Shin-Etsu Polymer Co., Ltd.) -402 ") was added and thoroughly mixed to obtain a pressure-sensitive adhesive composition.

(4) A PET film (polyethylene terephthalate film; “MRV38” manufactured by Mitsubishi Chemical Corporation) whose surface was subjected to a release treatment with silicone was prepared. The above-mentioned pressure-sensitive adhesive composition was applied to this PET film using a die coater. Thereafter, by drying at 90 ° C. for 3 minutes, the solvent component was volatilized from the adhesive composition to obtain an adhesive film having an adhesive layer having a thickness of 25 μm and a PET film.

The adhesive layer of this adhesive film was bonded to the first resin layer of the multilayer film. Then, it was aged by storing it for 5 days at a temperature of 23 ° C. and a humidity of 55%. Thereafter, the PET film was removed to obtain a polarizing film (see FIG. 1) having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.
The humidification reliability and the bending resilience of the obtained polarizing film were evaluated by the evaluation method described above.

[Example 2]
In the step (1-3), the thickness of the first resin layer was changed to 2 μm by adjusting the coating thickness of the resin solution.
Except for the above, the same operation as in Example 1 was carried out to produce and evaluate a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.

[Example 3]
In the step (1-1), the long raw film is changed to a 15 μm-thick unstretched polyvinyl alcohol film (vinylon film, average degree of polymerization of about 2400, saponification degree of 99.9 mol%), The thickness of the polarizer layer was changed to 5 μm. The degree of polarization of the polarizer layer manufactured in Example 3 was 99.995%.
In the step (1-3), the thickness of the first resin layer was changed to 2 μm by adjusting the coating thickness of the resin solution.
Except for the above, the same operation as in Example 1 was carried out to produce and evaluate a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.

[Example 4]
In the step (1-3), the resin X2 produced in Production Example 2 was used instead of the resin X1.
Except for the above, the same operation as in Example 1 was carried out to produce and evaluate a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.

[Example 5]
In the step (1-3), the resin X3 produced in Production Example 3 was used instead of the resin X1.
Except for the above, the same operation as in Example 1 was carried out to produce and evaluate a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.

[Example 6]
In the step (1-3), the resin X4 produced in Production Example 4 was used instead of the resin X1.
Except for the above, the same operation as in Example 1 was carried out to produce and evaluate a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.

[Example 7]
In the step (1-3), a resin solution containing the resin X5 prepared in Production Example 5 was used as a first resin solution. In the step (1-3), the thickness of the first resin layer to be formed was changed to 2 μm.
Except for the above, the same operation as in Example 1 was carried out to produce and evaluate a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / first resin layer / adhesive layer.

Example 8
By the same operation as in step (1-1) of Example 1, a polarizer layer was obtained. After applying the resin solution prepared in the step (1-3) of Example 1 to both surfaces of the polarizer layer, the resin solution was dried at 70 ° C. for 2 minutes to form a 4 μm thick first resin formed of the resin X1. A layer and a second resin layer were obtained. Thus, a multilayer film having a layer structure of first resin layer / polarizer layer / second resin layer was obtained.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film produced in step (1-4) of Practical Example 1 was bonded to the first resin layer of the multilayer film. Then, it was aged by storing it for 5 days at a temperature of 23 ° C. and a humidity of 55%. Thereafter, the PET film of the adhesive film was removed to obtain a polarizing film (see FIG. 2) having a layer structure of second resin layer / polarizer layer / first resin layer / adhesive layer.
The humidification reliability and the bending resilience of the obtained polarizing film were evaluated by the evaluation method described above.

[Example 9]
The resin X4 produced in Production Example 4 was mixed with cyclohexane as a solvent to obtain a resin solution as a first resin liquid and a resin solution containing the resin X4 at a concentration of 25% by weight. The resin solution containing the resin X4 was used instead of the resin solution containing the resin X1.
Except for the above, the same operation as in Example 8 was carried out to produce and evaluate a polarizing film having a layer structure of second resin layer / polarizer layer / first resin layer / adhesive layer.

[Comparative Example 1]
In the step (1-3), an acrylic resin layer was formed instead of the first resin layer containing the resin X1. Specifically, a mixture of 45 parts of N-hydroxyethylacrylamide (HEAA), 55 parts of acrylylmorpholine (ACMO), and 3 parts of a photopolymerization initiator (“IRGACURE907” manufactured by BASF) is used as an ultraviolet curable acrylic resin. Prepared. Then, instead of the resin solution containing the resin X1, the above-mentioned ultraviolet-curable acrylic resin was applied to the surface of the polarizer layer of the intermediate film obtained in the step (1-2) of Example 1, and then 750 mJ / cm ² was applied. An acrylic resin layer having a thickness of 2 μm was obtained by curing by irradiating ultraviolet rays.
Except for the above, the same operation as in Example 1 was performed to produce and evaluate a polarizing film having a layer structure of a protective film layer / adhesive layer / polarizer layer / acrylic resin layer / adhesive layer.

In Comparative Example 1, the storage elastic modulus and the water vapor transmission rate were measured for the cured acrylic resin as a component corresponding to the resin contained in the first resin layer. The measurement of the storage elastic modulus and the water vapor transmission rate was performed using a measurement film having a thickness of 1 mm and 100 μm produced by applying an acrylic resin to an appropriate surface and irradiating it with ultraviolet rays.

[Comparative Example 2]
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive film produced in step (1-4) of Example 1 was bonded to the surface of the polarizer layer of the intermediate film obtained in step (1-2) of Example 1. Then, it was aged by storing it for 5 days at a temperature of 23 ° C. and a humidity of 55%. Thereafter, the PET film of the adhesive film was removed to obtain a polarizing film having a layer structure of protective film layer / adhesive layer / polarizer layer / adhesive layer.
The humidification reliability and the bending resilience of the obtained polarizing film were evaluated by the evaluation method described above.

比較 In Comparative Example 2, the storage elastic modulus and the water vapor transmission rate were measured for the adhesive contained in the adhesive layer as a component corresponding to the resin contained in the first resin layer. The measurement of the storage elastic modulus and the water vapor transmission rate of the pressure-sensitive adhesive was performed using a 1-mm-thick and 100-μm-thick measurement film produced by the pressure-sensitive adhesive. The film for measurement was prepared by applying the pressure-sensitive adhesive composition on an appropriate surface, drying the solvent, and then aging by storing at 23 ° C. and 55% humidity for 5 days.

[result]
The results of the above-described Examples and Comparative Examples are shown in Table 1 below. In Table 1 below, the meanings of the abbreviations are as follows.
AC1: acrylic resin.
AC2: UV-cured acrylic resin.
PSA: adhesive.

100, 200 Polarizing film 110 Adhesive layer 120 First resin layer 130 Polarizer layer 140 Adhesive layer 150 Protective film layer 260 Second resin layer

Claims (13)

1. A polarizer layer, comprising a first resin layer directly in contact with the polarizer layer,
   A polarizing film, wherein the first resin layer is formed of a first resin having a storage elastic modulus of 10 MPa or more and 1000 MPa or less measured as a film having a thickness of 1 mm.
2. The polarizing film according to claim 1, wherein the thickness of the first resin layer is greater than 0 µm and 13 µm or less.
3. 偏光 The polarizing film according to claim 1, wherein the thickness of the polarizer layer is greater than 1 μm and 12 μm or less.
4. The polarizer layer, the first resin layer, and an adhesive layer, in this order,
   4. The polarizing film according to claim 1, wherein the thickness of the adhesive layer is 2 μm or more and 25 μm or less.
5. 5. The first resin according to claim 1, wherein the first resin has a water vapor transmission rate at 40 ° C. and 90% RH measured as a film having a thickness of 100 μm of 4 g / (m ² · day) or less. Polarizing film.
6. The polarizing film according to any one of claims 1 to 5, wherein the first resin contains a polymer having an alicyclic structure.
7. The polymer having the alicyclic structure,
   A polymer block [A] having a repeating unit [I] derived from an aromatic vinyl compound as a main component,
   A polymer block [B] containing a repeating unit [I] derived from an aromatic vinyl compound and a repeating unit [II] derived from a chain conjugated diene compound as a main component, or a repeating unit [II] derived from a chain conjugated diene compound A polymer block [C] containing, as a main component,
   The polarizing film according to claim 6, wherein the block copolymer [D] is a hydrogenated block copolymer.
8. (8) The polarizing film according to any one of (1) to (7), wherein the first resin contains a plasticizer and / or a softener.
9. The polarizing film according to claim 8, wherein the plasticizer and / or softener is at least one selected from the group consisting of an ester plasticizer and an aliphatic hydrocarbon polymer.
10. (10) The polarizing film according to any one of (1) to (9), wherein the first resin contains a moisture absorbent.
11. The polarizing film according to any one of claims 1 to 10, wherein the first resin contains an organometallic compound.
12. The first resin layer, the polarizer layer, and a second resin layer directly in contact with the polarizer layer, in this order,
    The polarizing film according to any one of claims 1 to 11, wherein the second resin layer is formed of a second resin having a storage elastic modulus measured as a film having a thickness of 1 mm of 10 MPa or more and 1000 MPa or less.
13. The method for producing a polarizing film according to any one of claims 1 to 12,
    Preparing a first resin liquid containing the first resin,
    Applying the first resin liquid to the polarizer layer.

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