TW202019710A - Polarizing plate with front plate - Google Patents

Abstract

The purpose of the present invention is to provide a polarizing plate with a front plate, which has a small decrease in optical performance over time and has excellent flexibility. The polarizing plate with a front plate comprises: a polarization plate having a diffusion prevention layer A, a polarizer, and a diffusion prevention layer B in this order; and a front surface plate disposed on an opposite side to the polarizer side in the diffusion prevention layer A or the diffusion prevention layer B, wherein the front surface plate is laminated on the polarization plate with an adhesive layer therebetween, the thickness of the diffusion prevention layer A and the diffusion prevention layer B is 20 [mu]m or less, the thickness of the polarizer is 10 [mu]m or less, and an adhesive forming the adhesive layer has a storage elastic modulus of 0.7 MPa or less at 25 DEG C.

Description

Polarizer with front panel

The invention relates to a polarizing plate with a front panel.

A polarizing plate equipped with a polarizing element is incorporated in a display device such as a liquid crystal display device or an organic EL (Electroluminescence) display device. As the polarizing element, in addition to a polarizing element in which a dichroic dye such as iodine is adsorbed on a polyvinyl alcohol-based resin film, a polarizing element manufactured by applying a composition containing a polymerizable liquid crystal to a substrate is also known . [Prior Technical Literature] [Patent Literature]

[Patent Literature 1] International Publication 2017/154907

[Problems to be solved by the invention]

In response to consumer expectations for thinning mobile devices, expecting a thin display device does not necessarily require a coated polarizer with the protective film necessary for the previous polarizer, which is easier to thin, so it is a very useful technology . However, such a coating-type polarizing element has a case where optical performance such as polarizing performance under a high-temperature environment deteriorates over time. It is also clear that the coated polarizing element is superior to the polarizing element in which a dichroic dye such as iodine is adsorbed on a polyvinyl alcohol-based resin film, in that the bending direction is not limited, but according to the type or arrangement of the front panel For the type of adhesive layer between the front panel and the polarizing plate, there is room for improvement in the flexibility.

Therefore, an object of the present invention is to provide a polarizing plate with a front panel that has less deterioration in optical performance over time in a high-temperature environment and is excellent in flexibility. [Technical means to solve the problem]

The present invention provides the following preferred aspects [1] to [11]. [1] A polarizing plate with a front panel, comprising: a polarizing plate having an anti-diffusion layer A, a polarizing element, and an anti-diffusion layer B in sequence, and A front panel is arranged on the side opposite to the polarizing element side of the anti-diffusion layer A or the anti-diffusion layer B, and The front panel is laminated on the polarizing plate via an adhesive, The thickness of the anti-diffusion layer A and the anti-diffusion layer B is 20 μm or less, The thickness of the polarizing element is 10 μm or less, The storage modulus of the adhesive forming the above adhesive layer at 25°C is 0.6 MPa or less. [2] The polarizing plate with a front panel according to [1], wherein the front panel includes a resin film containing a polyimide-based polymer or a polyamide-based polymer, and at least one main surface of the resin film Laminated film of the functional layer provided on the side. [3] The polarizing plate with a front panel as described in [2], wherein the above functional layer is a layer having at least one function selected from the group consisting of ultraviolet absorption, surface hardness, hue adjustment, and refractive index adjustment. [4] The polarizing plate with front panel as described in [2] or [3], wherein the tensile elastic modulus of the above resin film is 4.0 GPa or more, In the bending test in which the operation of bending the resin film into a U shape until the distance between the resin films becomes 3 mm and recovering is repeated, the number of bending times until the resin film is broken More than 100,000 times, The yellowness is 5 or less. [5] The polarizing plate with a front panel according to any one of [1] to [4], wherein the polarizing plate is provided with a retardation film on the opposite side of the polarizing element from the front panel side. [6] The polarizing plate with a front panel as described in [5], wherein the retardation film is laminated on the diffusion prevention layer A or the diffusion prevention layer B via an adhesive layer. [7] The polarizing plate with a front panel according to [5] or [6], wherein the retardation film includes a λ/4 retardation plate. [8] The polarizing plate with a front panel as described in any one of [1] to [7], which has a touch sensor. [9] An organic EL display device including a polarizing plate with a front panel as described in any one of [1] to [8]. [10] A flexible image display device including a polarizing plate with a front panel as described in any one of [1] to [8]. [Effect of invention]

The present invention can provide a polarizing plate with a front panel that has less deterioration in optical performance over time and has excellent flexibility.

<Polarizer with front panel> The polarizing plate with a front panel of the present invention includes: a polarizing plate having an anti-diffusion layer A, a polarizing element, and an anti-diffusion layer B in this order. The polarizing plate with a front panel of the present invention is further provided with a front panel disposed on the side opposite to the polarizing element side of the anti-diffusion layer A or the anti-diffusion layer B. The front panel is laminated on the polarizing plate via an adhesive. The thickness of the anti-diffusion layer A and the anti-diffusion layer B are both 20 μm or less, and the thickness of the polarizing element is 10 μm or less.

Hereinafter, embodiments of the present invention will be described in detail. In addition, the scope of the present invention is not limited to the embodiments described herein, and various changes can be made within a range that does not damage the gist of the present invention.

The configuration of the polarizing plate included in the polarizing plate with a front panel of the present invention will be described based on FIG. 1. The polarizing plate (10) with front panel of the present invention has an anti-diffusion layer A (2) on one area layer of the polarizing element (1), and an anti-diffusion layer B (3) on the other area layer of the polarizing element (1) ) Of the polarizer (20). By having the polarizing plate, for the polarizing plate with a front panel of the present invention, the movement of the dichroic pigment contained in the polarizing element to the outside of the film can be suppressed, so that the optical performance of the polarizing plate can be suppressed from decreasing with time. In addition, an alignment film (not shown) may be laminated between the polarizing element (1) and the diffusion prevention layer.

The polarizing plate with a front panel of the present invention has a front panel. This embodiment will be described based on FIG. 1. The polarizing plate (10) with a front panel of the present invention includes a front panel (4) disposed on the side opposite to the polarizing element (1) side of the diffusion prevention layer A (2). As shown in FIG. 1(a), the front panel (4) can be laminated on the polarizing plate (20) via an adhesive layer (7), for example. As shown in FIG. 1(b), the front panel (4) can be laminated on the polarizing plate (20) via the anti-diffusion layer A (2), for example.

In one embodiment of the present invention, the polarizing plate with front panel of the present invention may be provided with a retardation film (5). The polarizing plate may be provided with a retardation film on the side opposite to the front panel side of the polarizing element. In this case, the retardation film (5) can be disposed on the opposite side of the anti-diffusion layer B from the polarizing element side. The retardation film may be laminated on the anti-diffusion layer B via an adhesive layer or an adhesive layer, for example. The retardation film can be laminated on the polarizing plate via the anti-diffusion layer B. The present invention is not limited to the above configuration, and the embodiment in which the diffusion prevention layer A(2) in the above description is replaced with the diffusion prevention layer B(3) is also included in the invention. Hereinafter, each component of the polarizing plate with a front panel of the present invention will be described in detail.

<Polarizing element> The thickness of the polarizing element of the present invention is 10 μm or less, preferably 5 μm or less. In the case where the thickness exceeds 10 μm, there is a possibility that cracks or other defects may occur during bending. The polarizing element may be a film-type polarizing element manufactured by dyeing and stretching a polyvinyl alcohol (PVA)-based film. The dichroic dye such as iodine is absorbed in the PVA film aligned by stretching, or is stretched in a state of being adsorbed in PVA, whereby the dichroic dye is aligned to exert polarizing performance. In the manufacture of the above-mentioned film-type polarizing element, it may additionally have steps of swelling, cross-linking by boric acid, washing by an aqueous solution, and drying. The stretching or dyeing step can be performed on the PVA-based film alone or in a state of being laminated with other films such as polyethylene terephthalate. The PVA-based film used is preferably 10 to 100 μm, and the stretching magnification is 2 to 10 times.

The polarizing element is preferably a polymer containing a polymerizable liquid crystal and a dichroic dye, and more preferably a film in which a dichromatic dye is dispersed and aligned in a film containing a polymer of a polymerizable liquid crystal. Moreover, the polarizing element may be a film containing a dichroic dye and a polymer compound. The polarizing element of the present invention is preferably a film in which the polymerizable liquid crystal is aligned in a horizontal direction with respect to the plane of the diffusion prevention layer. The horizontal alignment refers to the alignment of the long axis of the polymerizable liquid crystal with alignment in the parallel direction with respect to the plane of the diffusion prevention layer. The so-called "parallel" refers to an angle of 0°±20° relative to the plane of the anti-diffusion layer.

When the polarizing element contains polymerizable liquid crystal, the thickness is preferably 0.5 μm to 3 μm, and more preferably 1 μm to 3 μm from the viewpoint of the alignment of the polymerizable liquid crystal. If the thickness of the polarizing element is more than the above lower limit, the polymerizable liquid crystal will not be easily aligned in the vertical alignment direction, so there is a tendency for the alignment order to increase. In addition, if the thickness of the polarizing element is equal to or less than the above upper limit value, the polymerizable liquid crystal is less likely to be randomly aligned, and therefore the alignment order tends to increase. The thickness of the polarizing element can be measured by an interference film thickness meter, a laser microscope, or a stylus film thickness meter.

The polarizing element is usually formed by coating a composition containing a polymerizable liquid crystal and a dichroic dye on the surface of a substrate, an anti-diffusion layer, or an alignment film (hereinafter, also referred to as "a composition for forming a polarizing element"), and making the polymerizable Obtained by liquid crystal polymerization. Here, it is preferable to polymerize the polymerizable liquid crystal in a state aligned in the horizontal direction with respect to the anti-diffusion layer. As a composition for forming a polarizing element and a method for manufacturing a polarizing element using the composition, those described in Japanese Patent Laid-Open No. 2017-83843 can be exemplified. In addition, the polarizing element can be manufactured from a dichroic dye and a polymer compound. As a polarizing element containing a dichroic dye and a polymer compound, those described in WO2017/154907 can be exemplified.

[Polymeric liquid crystal] The polymerizable liquid crystal refers to a compound having a polymerizable group and showing liquid crystallinity. The polymerizable group refers to a group participating in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in the polymerization reaction by active radicals or acids generated from the following photopolymerization initiator. Examples of the polymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, ethylene oxide, Oxetanyl, etc. Among them, preferred are propenyl oxy, methacryl oxy, ethyleneoxy, oxirane and oxetanyl, and more preferred is propylene oxy. The liquid crystal may be a thermotropic liquid crystal or a lyotropic liquid crystal.

The polymerizable liquid crystal may be a thermotropic liquid crystal compound showing a nematic liquid crystal phase, or a thermotropic liquid crystal compound showing a smectic liquid crystal phase. In the present invention, as a polymerizable liquid crystal, from the viewpoint of obtaining higher polarizing characteristics, a thermotropic liquid crystal compound showing a smectic liquid crystal phase is preferable, and a high order smectic liquid crystal phase is more preferable Thermotropic liquid crystal compound. Among them, it is more preferable to display smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase The thermotropic liquid crystal compound of the smectic L phase is more preferably a thermotropic liquid crystal compound showing the smectic B phase, smectic F phase or smectic I phase. If the liquid crystal phase formed by the polymerizable liquid crystal is the high-order smectic phase, a polarizing element with higher polarization performance can be manufactured. In addition, such a polarizing element with high polarizing performance obtains a Bragg wave peak derived from a hexagonal phase or a crystal higher order structure in X-ray diffraction measurement. The Bragg wave peak is derived from the peak of the periodic structure of molecular alignment, and a film with a period interval of 3 to 6 Å can be obtained. From the viewpoint of obtaining higher polarizing characteristics, it is preferable that the polarizing element contains a polymer of a polymerizable liquid crystal in which the polymerizable liquid crystal is polymerized in a smectic phase.

Specific examples of such compounds include compounds represented by the following formula (A) (hereinafter, sometimes referred to as compound (A)). The polymerizable liquid crystal may be used alone or in combination of two or more.

U ¹ -V ¹ -W ¹ -X ¹ -Y ¹ -X ² -Y ² -X ³ -W ² -V ² -U ² (A) [In formula (A), X ¹ , X ² and X ³ Independent of each other means a 1,4-phenylene group which may have a substituent or a cyclohexane-1,4-diyl group which may have a substituent; wherein at least one of X ¹ , X ² and X ³ may have a substituent Of 1,4-phenylene; -CH ₂ -that constitutes cyclohexane-1,4-diyl can be substituted with -O-, -S- or -NR-; R represents a C1-C6 alkane Group or phenyl group; Y ¹ and Y ² independently represent -CH ₂ CH ₂ -, -CH ₂ O-, -COO-, -OCOO-, single bond, -N=N-, -CR ^a =CR ^b- , -C≡C- or -CR ^a = N-; R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms of; the ^U-1 represents a hydrogen atom or a polymerizable group; U ² represents a polymerizable group ; W ¹ and W ² independently represent a single bond, -O-, -S-, -COO- or -OCOO-; V ¹ and V ² independently represent a C 1-20 alkanediyl group which may have a substituent , -CH ₂ -constituting the alkanediyl group may be substituted with -O-, -S- or -NH-]

In the compound (A), it is preferred that at least one of X ¹ , X ² and X ³ is 1,4-phenylene which may have a substituent. Here, the "may have a substituent" in this specification means the same as "unsubstituted or has a substituent". The 1,4-phenylene group which may have a substituent is preferably unsubstituted. The cyclohexane-1,4-diyl group which may have a substituent is preferably a trans-cyclohexane-1,4-diyl group which may have a substituent, and a trans-cyclohexane-1 which may have a substituent ,4-Diyl is preferably unsubstituted.

The 1,4-benzyl group which may have a substituent or the cyclohexane-1,4-diyl group which may have a substituent optionally has substituents such as methyl, ethyl, and butyl. ~4 alkyl, cyano and halogen atoms.

Y ^{1 is} preferably -CH ₂ CH ₂ -, -COO- or a single bond, and Y ^{2 is} preferably -CH ₂ CH ₂ -or -CH ₂ O-.

U ² is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, preferably a polymerizable group. U ¹ and U ^{2 are} preferably both polymerizable groups, and more preferably are both photopolymerizable groups. The polymerizable liquid crystal having a photopolymerizable group is advantageous in that it can be polymerized under lower temperature conditions.

The polymerizable groups represented by U ¹ and U ² may be different from each other, but are preferably the same. Examples of the polymerizable group include vinyl, vinyloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloyloxy, methacryloyloxy, ethylene oxide, Oxetanyl, etc. Among them, preferred are propenyl oxy, methacryl oxy, ethyleneoxy, oxirane and oxetanyl, and more preferred is propylene oxy.

Examples of the alkanediyl groups represented by V ¹ and V ² include methylene, ethylidene, propane-1,3-diyl, butane-1,3-diyl, and butane-1,4- Diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, decane-1,10- Diyl, tetradecane-1,14-diyl and eicosane-1,20-diyl etc. V ¹ and V ^{2 are} preferably C 2-12 alkanediyl groups, more preferably C6-12 alkanediyl groups. Examples of the optional substituents of the C 1-20 alkanediyl which may have a substituent include a cyano group and a halogen atom, but the alkanediyl group is preferably unsubstituted, more preferably unsubstituted and straight Chain dialkyl diyl.

W ¹ and W ² are independent of each other, preferably a single bond or -O-.

Specific examples of the compound (A) include compounds represented by formula (1-1) to formula (1-23), and the like. In the case where the compound (A) has cyclohexane-1,4-diyl, the cyclohexane-1,4-diyl is preferably a trans isomer.

In the exemplified compound (A), the polymerizable liquid crystal is preferably selected from the group consisting of formula (1-2), formula (1-3), formula (1-4), formula (-6), formula (1-7), At least one of the group consisting of the compounds represented by formula (1-8), formula (1-13), formula (1-14) and formula (1-15) respectively.

The exemplified compound (A) can be used alone or in combination in the polarizing element. Moreover, when combining two or more types of polymerizable liquid crystals, it is preferable that at least one kind is a compound (A), and it is more preferable that two or more kinds are a compound (A). By combining two or more polymerizable liquid crystals, there is a case where the liquid crystallinity can be temporarily maintained even at a temperature below the liquid crystal-crystal phase transition temperature. The mixing ratio when combining two polymerizable liquid crystals (liquid crystals other than compound (A): compound (A)) is usually 1:99 to 50:50, preferably 5:95 to 50:50, and more It is preferably 10:90 to 50:50 (mass ratio). When combining a polymerizable liquid crystal having one polymerizable group with a polymerizable liquid crystal having two polymerizable groups, the mixing ratio (polymerizable liquid crystal having one polymerizable group: polymerization having two polymerizable groups Liquid crystal) is usually 1:99-50:50, preferably 5:95-50:50, more preferably 10:90-50:50 (mass ratio).

The compound (A) can be produced by a known method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156, for example.

The content ratio of the polymerizable liquid crystal in the composition for forming a polarizing element is usually 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass relative to 100 parts by mass of the solid content of the composition for forming a polarizing element It is preferably 80 to 94 parts by mass, and more preferably 80 to 90 parts by mass. If the content ratio of the polymerizable liquid crystal is within the above range, the alignment tends to be high. Here, the solid content component means the total amount of components after removing the solvent from the composition for forming a polarizing element.

The composition for forming a polarizing element may contain a solvent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a leveling agent, and a reactive additive as components other than the polymerizable liquid crystal and the dichroic dye.

[Dichroic pigment] The dichroic dye contained in the composition for forming a polarizing element refers to a dye having a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction.

The dichroic dye is preferably one having an absorption maximum wavelength (λMAX) in the range of 300 to 700 nm. Examples of such dichroic dyes include acridine dyes, cyanine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes, among which azo dyes are preferred. Examples of azo dyes include monoazo dyes, disazo dyes, triazo dyes, tetraazo dyes, and stilbene dyes, and preferred are diazo dyes and triazo dyes. The dichroic pigments may be used alone or in combination of two or more, preferably three or more. It is particularly preferable to combine two or more azo compounds. A part of the dichroic pigment may have a reactive group and may have liquid crystallinity.

Examples of the azo dye include compounds represented by formula (B) (hereinafter, sometimes referred to as "compound (B)"). A ¹ (-N=NA ² ) _p -N=NA ³ (B) [In formula (B), A ¹ and A ^{3 are} independently of each other means a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a A monovalent heterocyclic group having a substituent; A ² represents a 1,4-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocycle which may have a substituent Ring group; p represents an integer of 1 to 4; when p is an integer of 2 or more, plural A ² may be the same or different from each other]

Examples of the monovalent heterocyclic group include a group obtained by removing one hydrogen atom from a heterocyclic compound such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. . Examples of the divalent heterocyclic group include a group obtained by removing two hydrogen atoms from the heterocyclic compound.

As phenyl, naphthyl and monovalent heterocyclic groups for A ¹ and A ³ , and p-phenylene, naphthalene-1,4-diyl and divalent heterocyclic groups for A ² optionally have substituents, Examples include: alkyl groups having 1 to 4 carbon atoms; alkoxy groups having 1 to 4 carbon atoms such as methoxy, ethoxy, and butoxy groups; fluorinated alkyl groups having 1 to 4 carbon atoms such as trifluoromethyl; Cyano group; nitro group; halogen atom; substituted or unsubstituted amine group such as amine group, diethylamino group and pyrrolidinyl group (so-called substituted amine group means having 1 or 2 carbon numbers 1 to 6) The amine group of the alkyl group, or two substituted alkyl groups are bonded to each other to form an amine group having 2 to 8 carbon atoms; the unsubstituted amine group refers to -NH ₂ ). Furthermore, specific examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, butyl, and hexyl.

In the compound (B), the azo dye is preferably a compound represented by the following formula (2-1) to formula (2-6), respectively.

[In formulas (2-1) to (2-6), B ¹ to B ²⁰ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, and a nitro group , Substituted or unsubstituted amine group (the definition of substituted or unsubstituted amine group is as described above), chlorine atom or trifluoromethyl group; n1 to n4 independently represent integers of 0 to 3; where n1 is In the case of 2 or more, the plurality of B ² may be the same or different from each other. In the case where n2 is 2 or more, the plurality of B ⁶ may be the same or different from each other. In the case of n3 is 2 or more, the plurality of B ⁹ They may be the same or different from each other. In the case where n4 is 2 or more, the plurality of B ¹⁴ may be the same or different from each other]

As the anthraquinone pigment, a compound represented by formula (2-7) is preferred.

[In formula (2-7), R ¹ to R ⁸ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x or a halogen atom; R ^x represents the carbon number 1 ～4 alkyl group or C 6-12 aryl group]

As the aforementioned pigment, the compound represented by formula (2-8) is preferred.

[In formula (2-8), R ⁹ to R ¹⁵ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom; R ^x represents the carbon number 1 ～4 alkyl group or C 6-12 aryl group]

As the acridine dye, a compound represented by formula (2-9) is preferred.

[In formula (2-9), R ¹⁶ to R ²³ independently represent a hydrogen atom, -R ^x , -NH ₂ , -NHR ^x , -NR ^x ₂ , -SR ^x, or a halogen atom; R ^x represents the carbon number 1 ～4 alkyl group or C 6-12 aryl group]

Examples of the alkyl group having 1 to 4 carbon atoms represented by R ^x in formula (2-7), formula (2-8) and formula (2-9) include methyl, ethyl, propyl and butyl Examples of the aryl group having 6 to 12 carbon groups, pentyl group and hexyl group include phenyl group, tolyl group, xylyl group and naphthyl group.

As the cyanine pigment, compounds represented by formula (2-10) and compounds represented by formula (2-11) are preferred.

n5表示1～3之整數][In formula (2-10), D ¹ and D ² independently represent the base represented by any one of formula (2-10a) to formula (2-10d);

n5 represents an integer from 1 to 3]

n6表示1～3之整數][In formula (2-11), D ³ and D ⁴ independently represent the base represented by any one of formula (2-11a) to formula (2-11h);

n6 represents an integer from 1 to 3]

The content of the dichroic dye in the composition for forming a polarizing element is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and still more preferably 0.1 to 10 parts by mass relative to the content of the polymerizable liquid crystal. Quality parts. If the content of the dichroic pigment is within the above range, the polymerizable liquid crystal can be polymerized without disturbing the alignment. If the content of the dichroic dye is too large, there is a possibility that the alignment of the polymerizable liquid crystal may be hindered. Therefore, the content of the dichroic pigment can also be determined within the range where the polymerizable liquid crystal can maintain the liquid crystal state.

[Solvent] The composition for forming a polarizing element may contain a solvent. As the solvent, those that can completely dissolve the polymerizable liquid crystal are preferred, and solvents that are inert to the polymerization reaction of the polymerizable liquid crystal are preferred.

Examples of the solvent include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and ethylene glycol Alcohol methyl ether acetate, γ-butyrolactone or propylene glycol methyl ether acetate and ethyl lactate and other ester solvents; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl Ketone solvents such as isobutanone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chloroform and Chlorinated solvents such as chlorobenzene. These solvents can be used alone or in combination of two or more.

The content of the solvent is preferably 50 to 98% by mass relative to the total amount of the polarizing element forming composition. In other words, the content of the solid content in the composition for forming a polarizing element is preferably 2 to 50% by mass. If the content of the solid component is 50% by mass or less, the viscosity of the composition for forming a polarizing element becomes low, so that the thickness of the polarizing element becomes substantially uniform, and thus there is a tendency for unevenness in the polarizing element to hardly occur. In addition, the content of the solid component can be determined in consideration of the thickness of the polarizing element to be manufactured.

[Polymerization initiator] The composition for forming a polarizing element may contain a polymerization initiator. The polymerization initiator is a compound that can start a polymerization reaction of a polymerizable liquid crystal or the like. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferred.

Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkyl benzophenone compounds, acyl phosphine oxide compounds, triammonium compounds, iodonium salts, and monium salts.

Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the benzophenone compound include benzophenone, methyl o-benzoyl benzoate, 4-phenyl benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide Ether, 3,3',4,4'-tetra (third butylcarbonyl peroxide) benzophenone and 2,4,6-trimethyl benzophenone, etc.

Examples of the alkyl benzophenone compounds include diethoxyacetophenone, 2-methyl-2-𠰌olinyl-1-(4-methylthienyl)propane-1-one, 2-benzyl -2-Dimethylamino-1-(4-𠰌olinylphenyl)butane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1,2-di Phenyl-2,2-dimethoxyethane-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propane-1-one, 1 -Oligomers of hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propane-1-one, etc.

Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzyl)phenylphosphine oxide. .

Examples of tris compounds include: 2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-tris, 2,4-bis(trichloro Methyl)-6-(4-methoxynaphthyl)-1,3,5-tris, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)- 1,3,5-tris, 2,4-bis(trichloromethyl)-6-[2-(5-methylfuran-2-yl)vinyl]-1,3,5-tris, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)vinyl]-1,3,5-tris, 2,4-bis(trichloromethyl)-6 -[2-(4-Diethylamino-2-methylphenyl)vinyl]-1,3,5-tris and 2,4-bis(trichloromethyl)-6-[2-( 3,4-dimethoxyphenyl)vinyl]-1,3,5-tris, etc.

As the polymerization initiator, commercially available ones can be used. Examples of commercially available polymerization initiators include Irgacure (registered trademark) 907, 184, 651, 819, 250, and 369 (manufactured by Ciba Specialty Chemicals Co., Ltd.); Seikuol (registered trademark) BZ, Z, and BEE (Seiko Chemical Co., Ltd.); kayacure (registered trademark) BP100 and UVI-6992 (Dow Chemical Co., Ltd.); Adeka Optomer SP-152 and SP-170 (ADEKA Co., Ltd.); TAZ-A and TAZ-PP (Manufactured by Nihon SiberHegner Co., Ltd.); and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.), etc.

The content of the polymerization initiator in the composition for forming a polarizing element can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal, and it is usually 0.1 to 30 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal, preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass. If the content of the polymerization initiator is within the above range, the polymerization can be carried out without disturbing the alignment of the polymerizable liquid crystal.

等𠮿酮化合物(例如2,4-二乙基-9-氧硫𠮿

、2-異丙基-9-氧硫𠮿

等)；蒽及含烷氧基之蒽(例如二丁氧基蒽等)等蒽化合物；啡噻𠯤及紅螢烯等。[Sensitizer] The composition for forming a polarizing element may contain a sensitizer. As the sensitizer, a photosensitizer is preferred. As the sensitizer, for example, 𠮿one and 9-oxosulfur 𠮿

And other ketone compounds (e.g. 2,4-diethyl-9-oxythio) 𠮿

、2-isopropyl-9-oxysulfur 𠮿

Etc.); anthracene and alkoxy-containing anthracene (such as dibutoxyanthracene, etc.) and other anthracene compounds;

When the composition for forming a polarizing element contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal contained in the composition for forming a polarizing element can be further promoted. The use amount of the sensitizer is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass relative to 100 parts by mass of the content of the polymerizable liquid crystal.

[Polymerization inhibitor] From the viewpoint of stably proceeding the polymerization reaction, the composition for forming a polarizing element may contain a polymerization inhibitor. The polymerization inhibitor can control the degree of polymerization of the polymerizable liquid crystal.

Examples of the polymerization inhibitor include hydroquinone, alkoxy-containing hydroquinone, alkoxy-containing catechol (such as butyl catechol, etc.), pyrogallol, 2,2,6,6-Tetramethyl-1-piperidineoxy radical and other free radical scavengers; thiophenols; β-naphthylamines and β-naphthols, etc.

When the composition for forming a polarizing element contains a polymerization inhibitor, the content of the polymerization inhibitor relative to the content of the polymerizable liquid crystal is 100 parts by mass, preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and It is preferably 0.5 to 8 parts by mass. If the content of the polymerization inhibitor is within the above range, polymerization can be performed without disturbing the alignment of the polymerizable liquid crystal.

[Leveling agent] The composition for forming a polarizing element may contain a leveling agent. The leveling agent refers to a function of adjusting the fluidity of the composition for forming a polarizing film to flatten the film obtained by coating the composition for forming a polarizing element, and examples include surfactants. Preferred leveling agents include leveling agents mainly composed of polyacrylate compounds such as "BYK-361N" (manufactured by BYK Chemie), and Surflon (registered trademark) "S-381" (AGC SEIMI CHEMICAL A leveling agent containing a compound containing fluorine atoms as the main component.

When the composition for forming a polarizing element contains a leveling agent, it is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 5 parts by mass, and still more preferably 0.5 to 100 parts by mass of the polymerizable liquid crystal. 3 parts by mass. If the content of the leveling agent is within the above range, there is a tendency that the polymerizable liquid crystal is easily aligned horizontally, and the obtained polarizing element tends to be smoother. If the content of the leveling agent with respect to the polymerizable liquid crystal exceeds the above range, the obtained polarizing element tends to be uneven. Furthermore, the composition for forming a polarizing element may contain two or more leveling agents.

[Reactive additive] The composition for forming a polarizing element may contain a reactive additive. As the reactive additive, those having a carbon-carbon unsaturated bond and an active hydrogen reactive group in the molecule are preferred. In addition, the "active hydrogen reactive group" herein refers to a group reactive with a group having active hydrogen such as a carboxyl group (-COOH), a hydroxyl group (-OH), an amine group (-NH ₂ ), etc. It is a glycidyl group, oxazoline group, carbodiimide group, aziridine group, imidate group, isocyanate group, thioisocyanate group, maleic anhydride group, etc. The number of carbon-carbon unsaturated bonds and active hydrogen reactive groups possessed by the reactive additive is usually 1 to 20, preferably 1 to 10, respectively.

Preferably, at least two active hydrogen reactive groups are present in the reactive additive. In this case, the presence of plural active hydrogen reactive groups may be the same or different.

The carbon-carbon unsaturated bond possessed by the reactive additive means a carbon-carbon double bond or a carbon-carbon triple bond or a combination of these, preferably a carbon-carbon double bond. Among them, the reactive additive preferably contains a carbon-carbon unsaturated bond in the form of a vinyl group and/or (meth)acryloyl group. Furthermore, it is preferable that the active hydrogen reactive group is at least one reactive additive selected from the group consisting of epoxy groups, glycidyl groups, and isocyanate groups, and it is more preferable to have an acryloyl group and an isocyanate group. Of reactive additives.

Specific examples of reactive additives include compounds having a (meth)acryloyl group and an epoxy group such as methacryloyloxyglycidyl ether or acryloxyglycidyl ether; oxetane acrylic acid Compounds such as esters or oxetane methacrylates with (meth)acryloyl and oxetanyl groups; lactone acrylates or lactone methacrylates with (meth)acryloyl groups Compounds with lactone groups; compounds with vinyl and oxazoline groups such as vinyl oxazoline or isopropenyl oxazoline; isocyanatomethyl acrylate, isocyanatomethyl methacrylate, acrylic acid 2 -Oligomers of compounds having (meth)acryloyl and isocyanate groups such as ethyl isocyanate and 2-isocyanate ethyl methacrylate. In addition, a compound having a vinyl group or a vinylidene group and an acid anhydride, such as methacrylic anhydride, acrylic anhydride, maleic anhydride, and vinyl maleic anhydride, may be mentioned. Among them, methacryloxyglycidyl ether, acryloxyglycidyl ether, isocyanatomethyl acrylate, isocyanatomethyl methacrylate, vinyl oxazoline, acrylic acid 2- Ethyl isocyanate, 2-isocyanatoethyl methacrylate and the above oligomers, particularly preferably isocyanatomethyl acrylate, 2-isocyanatoethyl acrylate and the above oligomers Thing.

Specifically, the compound represented by the following formula (Y) is preferable.

[In the formula (Y), n represents an integer of 1 up to 10, R ^{1 'represents} 2 to 20 carbon atoms of a divalent aliphatic or alicyclic hydrocarbon group having 5 to 20 carbon atoms or the divalent aromatic hydrocarbon group; each repeating Of the two R ^2's in the unit, one is -NH- and the other is a group represented by >NC(=O)-R ^3' ; R ^3'represents a hydroxyl group or a group having a carbon-carbon unsaturated bond ; In R ^3′ in formula (Y), at least one R ^3′ is a group having a carbon-carbon unsaturated bond]

Among the reactive additives represented by the above formula (Y), the compound represented by the following formula (YY) (hereinafter sometimes referred to as the compound (YY)) is particularly preferred (n is the same as the above).

The compound (YY) can be used as it is as a commercially available product or purified as necessary. Examples of commercially available products include Laromer (registered trademark) LR-9000 (manufactured by BASF).

When the composition for forming a polarizing element contains a reactive additive, the content of the reactive additive is usually 0.01 to 10 parts by mass, preferably 0.1 to 5 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal.

<Alignment film> In the present invention, the alignment film is a film containing a polymer compound, and has an alignment restricting force that aligns the polymerizable liquid crystal in a desired direction.

The alignment film makes the liquid crystal alignment of the polymerizable liquid crystal easy. The state of liquid crystal alignment such as horizontal alignment, vertical alignment, mixed alignment, and inclined alignment varies depending on the properties of the alignment film and the polymerizable liquid crystal, and the combination can be arbitrarily selected. For example, if the alignment film exhibits horizontal alignment as a material for alignment limitation, the polymerizable liquid crystal may form horizontal alignment or mixed alignment, and if the alignment film is a material that exhibits vertical alignment, the polymerizable liquid crystal may form vertical alignment or oblique alignment. The expressions such as horizontal and vertical indicate the direction of the long axis of the aligned polymer liquid crystal when the plane of the polarizing element is used as a reference. The horizontal alignment refers to the long axis of the polymerizable liquid crystal having alignment in the parallel direction with respect to the plane of the polarizing element. "Parallel" here refers to an angle of 0°±20° relative to the plane of the polarizing element. The vertical alignment refers to the long axis of the polymerizable liquid crystal having alignment in the vertical direction with respect to the plane of the polarizing element. The vertical here refers to 90°±20° relative to the plane of the polarizing element.

As the alignment limiting force, when the alignment film is formed of an alignment polymer, it can be arbitrarily adjusted by the surface state or friction conditions, and when it is formed of a photo-alignment polymer, it can be illuminated by polarized light, etc. And adjust arbitrarily. Also, the liquid crystal alignment can be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal.

As the alignment film formed between the anti-diffusion layer and the polarizing element, it is preferably insoluble in the solvent used when forming the polarizing element on the alignment film, and has heat resistance in heat treatment for removing the solvent or aligning the liquid crystal By. Examples of the alignment film include an alignment film containing an alignment polymer, a light alignment film, a groove alignment film, and the like, and a light alignment film is preferred.

The thickness of the alignment film is usually in the range of 10 nm to 500 nm, preferably in the range of 10 nm to 200 nm, and more preferably in the range of 30 to 100 nm.

Examples of the alignment polymer include polyamidoamines or gelatins having an amide bond in the molecule, polyimides having an amide imide bond in the molecule, and polyamic acid, polyvinyl alcohol, and hydrolyzate thereof. Alkyl modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethylenimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid and polyacrylates, etc. Among them, polyvinyl alcohol is preferred. These alignment polymers may be used alone or in combination of two or more.

An alignment film containing an alignment polymer can generally be obtained by applying a composition in which the alignment polymer is dissolved in a solvent (hereinafter also referred to as "alignment polymer composition") to the diffusion prevention layer, The solvent is removed, or the alignment polymer composition is applied to the anti-diffusion layer, the solvent is removed, and rubbing is performed (friction method).

Examples of the solvent include water; alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, and ethylene glycol Alcohol methyl ether acetate, γ-butyrolactone, propylene glycol methyl ether acetate and ethyl lactate and other ester solvents; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methylpentanone and methyl Ketone solvents such as isobutanone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chloroform and Chlorine-substituted hydrocarbon solvents such as chlorobenzene. These solvents can be used alone or in combination of two or more.

The concentration of the alignment polymer in the alignment polymer composition may be within a range where the alignment polymer can be completely dissolved in the solvent, and is preferably 0.1 to 20% by mass relative to the solution in terms of solid content. It is preferably 0.1 to 10% by mass.

As the alignment polymer composition, commercially available alignment film materials can be used directly. Examples of commercially available alignment film materials include Sunever (registered trademark) (manufactured by Nissan Chemical Industry Co., Ltd.) and Opterer (registered trademark) (manufactured by JSR Corporation).

Examples of the method for applying the alignment polymer composition to the diffusion prevention layer include spin coating, extrusion coating, gravure coating, die coating, bar coating, and dressing. Known methods such as coating methods and printing methods such as flexographic methods. In the case of manufacturing a polarizing plate by a roll-to-roll (Continuous Roll-to-Roll) manufacturing method, the coating method generally uses a printing method such as a gravure coating method, a die coating method, or a flexographic method.

By removing the solvent contained in the alignment polymer composition, a dry coating of the alignment polymer is formed. Examples of the method for removing the solvent include a natural drying method, an air drying method, a heating drying method, and a reduced pressure drying method.

As a rubbing method, the following method may be mentioned: a film of the oriented polymer formed on the surface of the diffusion prevention layer by applying the orientation polymer composition to the diffusion prevention layer and annealing, and rotation with the friction cloth wound Friction roller contact.

The photo-alignment film can generally be coated with a composition containing a polymer or monomer having a photoreactive group and a solvent (hereinafter also referred to as a "composition for forming an photo-alignment film") on the diffusion prevention layer, and irradiated with polarized light (Preferably polarized UV (ultraviolet, ultraviolet)). From the aspect that the direction of the alignment restricting force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light, the light alignment film is better.

The so-called photoreactive group refers to a group that generates liquid crystal alignment ability by irradiating light. Specifically, a photoreactor that becomes the origin of liquid crystal alignment ability, such as alignment induction or isomerization reaction, dimerization reaction, photocrosslinking reaction, or photolysis reaction, which is generated by irradiation of light, occurs. Among the photoreactive groups, in terms of excellent alignment, those that cause a dimerization reaction or a photocrosslinking reaction are preferred. As the photoreactive group capable of generating the reaction as described above, it is preferable to have an unsaturated bond, especially to have a double bond, and it is more preferable to have a carbon-carbon double bond (C=C bond) or a carbon-nitrogen double bond. (C=N bond), nitrogen-nitrogen double bond (N=N bond) and carbon-oxygen double bond (C=O bond) group of at least one group.

Examples of the photoreactive group having a C=C bond include a vinyl group, a polyalkenyl group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamyl group. Examples of the photoreactive group having a C=N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of the photoreactive group having an N=N bond include azophenyl group, azonaphthyl group, aromatic heterocyclic azo group, disazo group and mesityl group, etc. or based on azobenzene oxide Constructor. Examples of the photoreactive group having a C=O bond include benzophenone group, coumarin group, anthraquinone group, maleimide group, and the like. Such groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

The solvent for the composition for forming an optical alignment film is preferably one that dissolves a polymer and monomer having a photoreactive group. Examples of the solvent include the solvents listed as the solvents for the above-mentioned alignment polymer composition. .

The content of the polymer or monomer having a photoreactive group with respect to the composition for forming an optical alignment film may be appropriate according to the type of the polymer or monomer having a photoreactive group or the thickness of the optical alignment film to be manufactured The adjustment is preferably 0.2% by mass or more, and more preferably 0.3 to 10% by mass. In addition, it can contain polymer materials such as polyvinyl alcohol or polyimide or photosensitizers within a range that does not significantly impair the characteristics of the optical alignment film.

As a method of applying the composition for forming an optical alignment film to the diffusion prevention layer, the same method as the method of applying the alignment polymer composition to the diffusion prevention layer described above may be mentioned. Examples of the method for removing the solvent from the composition for forming a photo-alignment film for coating include the same method as the method for removing the solvent from the alignment polymer composition.

The polarized light irradiation may be a form in which polarized light is directly irradiated to the person obtained by removing the solvent from the composition for forming an optical alignment film coated on the anti-diffusion layer or the like, or may be irradiated with polarized light from the anti-diffusion layer side to transmit the polarized light form. Furthermore, the polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably a wavelength region in which the light-reactive group of the polymer or monomer having a light-reactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength of 250 to 400 nm is particularly preferred. Examples of the light source used in the polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, KrF, ArF and other ultraviolet lasers, and more preferably high-pressure mercury lamps, ultra-high pressure mercury lamps, or metal halides Object lights. These lamps are preferred because of the high intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by irradiating light from a light source through an appropriate polarizing element. As the polarizing element, a polarizing filter or a polarizing element such as Glan-Thompson and Glan-Taylor or a wire grid type polarizing element can be used.

Furthermore, when rubbing or polarized light irradiation, if shielding is performed, a plurality of regions (patterns) with different liquid crystal alignment directions can also be formed.

A groove alignment film is a film having a concave-convex pattern or a plurality of grooves (grooves) on the surface of the film. When liquid crystal molecules are placed on a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction of their grooves.

As a method of obtaining a groove alignment film, a method of forming a concave-convex pattern after exposing the surface of the photosensitive polyimide film through an exposure mask having slits having a pattern shape, then performing development and rinsing treatment ; A method of forming a UV-curable resin layer before curing on a plate-shaped master with grooves on the surface, and moving the resin layer to the anti-diffusion layer for curing; and pressing the roller-shaped master with multiple grooves against A method of forming irregularities on the UV-curable resin film formed on the anti-diffusion layer before curing, followed by curing. Specific examples include the methods described in Japanese Patent Laid-Open No. 6-34976 and Japanese Patent Laid-Open No. 2011-242743.

In order to obtain alignment with less alignment disorder, the width of the convex portion of the groove alignment film is preferably 0.05 μm to 5 μm, the width of the concave portion is preferably 0.1 μm to 5 μm, and the depth of the step difference of the concave and convex is preferably 2 μm Below, it is preferably 0.01 μm to 1 μm or less.

<Anti-diffusion layer A and B> The polarizing plates each have an anti-diffusion layer (anti-diffusion layer A) on one side of the polarizing element, and another anti-diffusion layer (anti-diffusion layer B) on the other side. In the polarizing plate, the anti-diffusion layer A or B is preferably in contact with the polarizing element, and more preferably both the anti-diffusion layers A and B are in contact with the polarizing element. In this case, there is no hindrance to the existence of the alignment film between the polarizing element and the anti-diffusion layer A or B. The anti-diffusion layers A and B are layers capable of suppressing the movement of the dichroic pigment from the polarizing element. As a result, it is possible to suppress the degradation of the polarizing performance of the polarizing element with time. In addition, since both the anti-diffusion layers A and B have a thickness of 20 μm or less, the thickness of the polarizing plate can be reduced. By providing the polarizing plate with anti-diffusion layers A and B, when the polarizing plate is laminated on another member (adhered body), even if the other member has a step (concavo-convex) in shape, the polarizing element can be reduced Variation in film thickness can achieve uniform polarization performance within the film. In this specification, the adhered system refers to a member to be transferred when the polarizing plate is transferred from the base material, and a member to be stacked when the polarizing plate is not transferred and stacked. Examples of such members include members applying polarizing plates such as front panels and retardation films. Furthermore, the diffusion prevention layers A and B preferably help prevent shrinkage and expansion of the polarizing element, and prevent deterioration of the polarizing element due to temperature, humidity, ultraviolet rays, and the like.

As materials constituting the anti-diffusion layers A and B, those having excellent solvent resistance, transparency, mechanical strength, thermal stability, shielding properties, isotropy, etc. are preferred. It should have at least the transparency that can withstand the use as a polarizing plate and the anti-diffusion ability to suppress the movement of the dichroic pigment.

The anti-diffusion layers A and B, which have the function of preventing the movement (diffusion) of the dichroic pigment, preferably include materials having low compatibility with the dichroic pigment. Examples of such materials include photocurable resins and water-soluble polymers. The photocurable resin is highly polymerized, so that the diffusion of dichroic pigments can be prevented. The polarities of the water-soluble polymer and the dichroic pigments are very different, so the diffusion of dichroic pigments can be prevented.

Preferably, at least one selected from the group consisting of anti-diffusion layers A and B specifically contains: polypropylene amide polymer; polyvinyl alcohol and ethylene-vinyl alcohol copolymer, (meth)acrylic acid or Its anhydride-vinyl alcohol copolymer and other vinyl alcohol-based polymers; carboxyvinyl polymer; polyvinylpyrrolidone; starch; sodium alginate; or polyethylene oxide-based polymer and other water-soluble polymers. Moreover, it is preferable that at least one selected from the group consisting of the diffusion prevention layers A and B contains: acrylic, urethane, acrylic urethane, epoxy, or polysiloxane Is photo-curable resin. Among them, from the viewpoint that the function of shielding the dichroic pigment in the polarizing element is more excellent, it is preferable that at least one selected from the group consisting of the diffusion prevention layers A and B contains a water-soluble polymer, preferably One of the anti-diffusion layers contains a water-soluble polymer, and the other anti-diffusion layer contains a photocurable resin. The material constituting the anti-diffusion layer A and the material constituting the anti-diffusion layer B may be the same or different. In addition, the diffusion prevention layer A and the diffusion prevention layer B may be the same or different. In this specification, it is sometimes abbreviated as "anti-diffusion layer", which means that the anti-diffusion layer may be any of the anti-diffusion layer A and the anti-diffusion layer B.

The content of the polymer in the diffusion prevention layers A and B is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 99% by mass or more. In addition, the anti-diffusion layers A and B may contain the above polymers alone, or may contain two or more kinds in combination.

The glass transition temperature of the anti-diffusion layers A and B is preferably more than 25°C (room temperature), preferably 40°C or more. In addition, the glass transition temperature of the polymer constituting the anti-diffusion layer A or B is preferably 25°C (room temperature) or higher, and preferably 40°C or higher. That is, the diffusion prevention layers A and B are preferably layers that are cured at room temperature. With such a layer, the diffusion of the dichroic dye to the diffusion prevention layers A and B can be prevented, and the optical performance of the polarizing plate can be further reduced over time.

In addition, the content of the low-molecular-weight molecules of 1000 or less in the diffusion prevention layers A and B is preferably 1% by mass or less, and more preferably 0.1% by mass or less. With such a layer, the diffusion of the dichroic dye to the diffusion prevention layers A and B can be prevented, and the optical performance of the polarizing plate can be further reduced over time.

It is preferable that the anti-diffusion layers A and B show good adhesion to the adherend, respectively, and the polarizing plate can be adhered to a desired area and used for the lamination layer of the polarizing plate. With such anti-diffusion layers A and B, the polarizing plate can be directly laminated on the adherend, so that the resulting laminated body can be made thinner. Examples of the polymer constituting the anti-diffusion layer showing adhesion to the adherend include vinyl alcohol-based polymers and those selected from the group consisting of epoxy-based cross-linking agents, amide-based cross-linking agents, and acrylic-based cross-linking agents. A mixed composition of at least one crosslinking agent in the group.

The thicknesses of the anti-diffusion layers A and B are each 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, and further preferably 5 μm or less. In addition, the thicknesses of the anti-diffusion layers A and B are preferably 0.05 μm or more. The thickness of at least one of the anti-diffusion layers A and B, especially the thickness of the anti-diffusion layers A and B, are preferably in the above-mentioned ranges, further preferably in the range of 0.05 μm to 5 μm, more preferably 0.05 μm to 3 μm, and It is preferably 0.5 μm to 3 μm. Especially in the case where the surface of the anti-diffusion layer A or B opposite to the polarizing element has an adhesive layer, the thickness of at least one of the anti-diffusion layers A or B, especially the thicknesses of A and B of the anti-diffusion layer are It is preferably 0.5 μm to 20 μm, more preferably 0.5 to 10 μm, still more preferably 0.5 to 5 μm, and particularly preferably 0.5 μm to 3 μm. In this case, by making the anti-diffusion layer have a thickness of 0.5 μm or more, the movement of the dichroic pigment to the adhesive layer can be sufficiently suppressed. In the case where the adhesive layer is not formed on the surface of the anti-diffusion layer opposite to the polarizing element, by making the anti-diffusion layer have a thickness of 0.05 μm to 3 μm, the movement of the dichroic pigment to the adhesive layer can be sufficiently suppressed . The thickness of the anti-diffusion layer A and the thickness of the anti-diffusion layer B may be the same or different. Furthermore, the anti-diffusion layers A and B may be a single layer, or may include multiple layers.

The diffusion prevention layers A and B may have a surface treatment layer on the surface opposite to the polarizing element. Examples of the surface treatment layer include optical layers such as hard coat layers, anti-reflection layers, anti-sticking layers, anti-glare layers, and diffusion layers.

The hard coat layer is for the purpose of preventing damage to the surface of the polarizing plate. For example, by adding an ultraviolet curing resin such as acrylic or polysiloxane to the surface of the anti-diffusion layer, it is excellent in hardness and sliding characteristics. The method of hardening the film is formed. The anti-reflection layer is intended to prevent the reflection of light outside the surface of the polarizer, and can be achieved by the formation of a previous anti-reflection film or the like. In addition, the anti-sticking layer is intended to prevent the adhesion of the layer to which it is connected.

The anti-glare layer is intended to prevent the reflection of external light on the surface of the polarizing plate and prevent the polarizing plate from seeing through the light. For example, it can be formed by the following method: using a rough surface by sandblasting or embossing The micro-concavo-convex structure is given to the surface of the anti-diffusion layer by means of chemical conversion method or method of blending transparent fine particles. Examples of fine particles contained for forming the above-mentioned fine uneven structure on the surface include silicon dioxide, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, indium oxide, cadmium oxide, and the like having an average particle diameter of 0.5 to 50 μm. Transparent fine particles such as antimony oxide and other organic fine particles that can have conductivity, and organic fine particles including cross-linked or uncross-linked polymers. In the case of forming a fine surface uneven structure, the content of fine particles is usually 2-50 parts by mass, preferably 5-25 parts by mass relative to 100 parts by mass of the transparent resin forming the surface fine uneven structure. The anti-glare layer also serves as a diffusion layer (different viewing angle expansion function, etc.) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

Furthermore, the anti-reflection layer, the anti-sticking layer, the diffusion layer, the anti-glare layer, etc. may be provided on the anti-diffusion layer and integrated, and may also be provided as an additional optical layer by being separated from the anti-diffusion layer into a separate body. .

The anti-diffusion layers A and B are usually suitable by applying a solution of the material constituting each anti-diffusion layer (hereinafter also referred to as "anti-diffusion layer composition") to a substrate, an alignment film, a polarizing element, a front panel, etc. It is obtained by hardening the component. When the anti-diffusion layer composition is a composition obtained by dissolving the material constituting the anti-diffusion layer in a solvent, the material constituting the anti-diffusion layer may be hardened by removing the solvent, or the solvent may be removed It is then hardened by chemical reaction. The anti-diffusion layer composition may be applied to the above-mentioned member to harden it, or after being applied to the above-mentioned member, it may be further layered on another member to harden it.

The solvent may be any one that dissolves the material constituting the anti-diffusion layer, and examples thereof include the solvents listed as the solvents of the above-mentioned alignment polymer composition.

The concentration of the material constituting the anti-diffusion layer in the anti-diffusion layer composition in terms of solid content is preferably 0.1 to 20% by mass, and more preferably 0.1 to 10% by mass.

Examples of the method for applying the anti-diffusion layer composition to the substrate and the method for removing (drying) the solvent include the same methods as described in the above-mentioned alignment polymer composition.

The anti-diffusion layer may be provided on the polarizing element by appropriately selecting from the materials listed above to prevent the migration of the dichroic pigment, and may also be used for any layer containing an active energy ray-curable resin. The anti-diffusion layer may be formed on at least one side of the retardation layer containing the liquid crystal polymerizable compound, for example. In this case, the anti-diffusion layer can realize the function of resisting impact or preventing cracks caused by bending.

<Manufacturing method of polarizing plate> The polarizing plate can be manufactured by the method described in Japanese Patent Laid-Open No. 2017-83843, for example. The polarizing plate can be manufactured by laminating monolithic members cut into a specific shape to each other, or by laminating elongated members to each other.

<Adhesive layer> The polarizing plate may have an adhesive layer on the opposite side of the anti-diffusion layer from the polarizing element side. The adhesive layer is formed from the adhesive. With the adhesive layer, the adhesion of the polarizing plate to the adherend becomes good, and the polarizing function derived from the polarizing element can be easily given to the desired area.

The adhesive usually contains a polymer, and may further contain a solvent. Examples of the above-mentioned polymers include acrylic polymers, polysiloxane polymers, polyesters, polyurethanes, and polyethers. Among them, acrylic adhesives containing acrylic polymers have excellent optical transparency, moderate wettability and cohesive force, excellent adhesion, and further good weather resistance and heat resistance. Under conditions, it is not easy to produce bumps and peeling.

As the above-mentioned acrylic polymer, it is preferable that the (meth)acrylate of the alkyl group of the ester portion is an alkyl group having a carbon number of 20 or less such as methyl, ethyl, or butyl (hereinafter, acrylate, methyl Acrylic acid esters are collectively referred to as (meth)acrylic acid esters. Acrylic acid and methacrylic acid are collectively referred to as (meth)acrylic acid) and (meth)acrylic acid or hydroxyethyl (meth)acrylic acid and other functional groups (meth)acrylic acid It is a monomeric polymer.

The adhesive containing such a copolymer has excellent adhesion, and after being attached to a display device, no paste residue will be generated on the display device during removal, and can be easily removed. The glass transition temperature of the acrylic polymer is preferably 25°C or lower, and more preferably 0°C or lower. The weight average molecular weight of this acrylic polymer is preferably 100,000 or more.

As said solvent, the solvent etc. mentioned as the solvent of the said alignment polymer composition are mentioned, for example.

The storage modulus of the above adhesive at 25°C is preferably 1×10 ⁶ Pa (1 MPa) or less, more preferably 5×10 ⁵ Pa (0.5 MPa) or less, and further preferably 3×10 ⁵ Pa (0.3 MPa) or less. If the storage modulus is 1×10 ⁶ Pa (1 MPa) or less, bubbles are not easily generated due to bending, and display unevenness is not likely to occur, which is preferable. The storage modulus is preferably 1×10 ⁴ Pa (0.01 MPa) or more, more preferably 2×10 ⁴ Pa (0.02 MPa) or more, and still more preferably 3×10 ⁴ Pa (0.03 MPa) or more. If the storage modulus is 1×10 ⁴ Pa (0.01 MPa) or more, there is a tendency that the adhesive is not easily attached to other parts during the manufacturing operation, which is preferable. The storage modulus of the adhesive at 80°C is preferably 5×10 ⁵ Pa (0.5 MPa) or less, more preferably 3×10 ⁵ Pa (0.3 MPa) or less, and further preferably 1×10 ⁵ Pa( 0.1 MPa) or less, particularly preferably 5×10 ⁴ Pa (0.05 MPa) or less, and particularly preferably 3×10 ⁴ Pa (0.03 MPa) or less. If the storage modulus at 80° C. is 5×10 ⁵ Pa (0.5 MPa) or less, the fluidity during the heating operation is good, so the generation of bubbles and the like tend to be suppressed, which is preferable.

In the adhesive layer formed on the side opposite to the polarizing element side of the anti-diffusion layer, the storage modulus at 25°C of the adhesive forming the adhesive layer disposed between the front panel and the polarizing plate is 0.6 MPa or less. The storage modulus is preferably 0.5 MPa or less, more preferably 0.1 MPa or less, and preferably 0.01 MPa or more. By laminating the front panel and the polarizing plate with an adhesive showing the above storage modulus, the stress generated in the anti-diffusion layer or the retardation film can be relieved when the polarizing plate with the front panel is bent. It is easy to improve the bendability of the polarizing plate with front panel. Furthermore, the storage modulus of the adhesive at 25°C was measured by the method described in the following examples.

In addition, the adhesive may contain a light diffusing agent. The light diffusing agent is used to impart light diffusibility to the adhesive, as long as it is a microparticle having a refractive index different from that of the polymer contained in the adhesive. Examples of the light diffusing agent include microparticles containing inorganic compounds and Microparticles containing organic compounds (polymers). Including the above-mentioned acrylic polymer, most of the polymers contained in the adhesive as an active ingredient have a refractive index of about 1.4, so it is suitable as a light diffusing agent from light diffusing agents whose refractive index is about 1-2 Just choose. The difference in refractive index between the polymer contained in the adhesive as an active ingredient and the light diffusing agent is usually 0.01 or more, and from the viewpoint of the brightness and displayability of the display device, it is preferably 0.01 or more and 0.5 or less. The fine particles used as the light diffusing agent are preferably spherical and close to monodisperse. For example, fine particles with an average particle diameter in the range of about 2 to 6 μm can be preferably used.

The refractive index is measured by the usual minimum declination method or Abbe refractometer.

Examples of fine particles containing an inorganic compound include aluminum oxide (refractive index 1.76) and silicon oxide (refractive index 1.45).

Examples of fine particles containing organic compounds (polymers) include melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), and methyl methacrylate/styrene copolymer resin beads. Particles (refractive index 1.50 to 1.59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46) ) And polysiloxane beads (refractive index 1.46), etc.

The formulation amount of the light diffusing agent is appropriately determined in consideration of the haze value required for the adhesive layer formed from the adhesive, or the brightness of the display device to which it is applied, and is usually 3 to 100 parts by mass relative to the content of the polymer 30 parts by mass.

As the haze value of the adhesive layer formed from the adhesive in which the light diffusing agent is dispersed, from the viewpoint of ensuring the brightness of the display device using a polarizing plate and not easily causing blooming or blurring of the displayed image, it is preferably Set to a range of 20 to 80%. The haze value is a value expressed by (diffused transmittance/total light transmittance) × 100 (%), and is measured in accordance with JIS K 7105.

The thickness of the adhesive layer formed by the self-adhesive is determined according to its adhesion, etc., and is not particularly limited, but is usually 1 to 40 μm. From the aspects of workability and durability, the thickness is preferably 5 to 25 μm, and more preferably 5 to 15 μm. By setting the thickness of the adhesive layer formed from the adhesive to about 5 to 15 μm, the adherend and the polarizing element can be sufficiently adhered, and the overall thickness of the display can be reduced.

<front panel> The polarizing plate includes a front panel disposed on the side opposite to the polarizing element side of the diffusion prevention layer. The front panel can be laminated on the polarizing plate through an adhesive layer or an anti-diffusion layer.

The front panel is responsible for suppressing warpage of an image display element such as a liquid crystal cell or protecting the image display element, and is, for example, a transparent (preferably optically transparent) plate-shaped body. The front panel can be a single-layer structure or a multi-layer structure.

The front panel is arranged on the outermost surface in the final product, so it is required to display sufficient durability when used outdoors or semi-outdoor. Furthermore, the front panel also requires durability against bending. From such a viewpoint, the front panel preferably includes a polymer film having a tensile elastic modulus of 2 GPa or more. When the front panel is used for a flexible display, it preferably contains a resin film, and the resin film particularly preferably contains a polycarbonate resin (tensile elastic modulus of 2 to 3 GPa) and an acrylic resin (tensile elastic modulus of 3 to 4 GPa) ), Polyimide resin (Tensile modulus of elasticity 3 to 5 GPa), Polyamide resin (Tensile modulus of elasticity 3 to 8 GPa), Polyamide imide resin (Tensile modulus of elasticity 3 to 3) 13 GPa), polyether resin (tensile modulus of elasticity 2 to 3 GPa). From the viewpoint of thinning, lightening, and softening of the display, acrylic resins and laminate films that impart scratch resistance to the resin, or containing polyimide, polyamide, or polyamide amide imide and A composite material of organic materials and inorganic materials such as a hybrid film of silicon dioxide. In particular, as a display member or a front panel of a flexible device, from the viewpoint of flexibility and visibility, a mixed film containing a polyimide-based polymer or a polyamide-based polymer and silicon dioxide is more preferable.

The integration of the front panel and the polarizing plate can be achieved by attaching these through the adhesive layer as necessary. The adhesive layer can be used as described above. When the polarizer contains an adhesive layer, in order to eliminate reflection or light scattering at the interface between the front panel and the polarizer, and improve visibility, it is preferable that the refractive index of the adhesive is close to or the same as the refractive index of the front panel. Furthermore, it is preferably optically transparent. In addition, the adhesive layer can also be suitably adjusted for viscoelasticity, such as 25°C storage modulus, tan δ, stress relaxation rate, etc.

The polarizing plate with a front panel of the present invention can suppress warping of image display elements such as liquid crystal cells, and can prevent damage to the image display elements. Furthermore, when the front panel is in a flexible form (polymer film), it can be continuously manufactured by roll-to-roll, and in this respect, the polarizing plate with front panel of the present invention is also better .

As one embodiment of the front panel, it will be described in detail using FIG. 4. As one preferred embodiment of the front panel, it is a laminated film of a resin film containing a polyimide-based polymer or a polyamide-based polymer and a functional layer provided on at least one side of the resin film.

(Resin film) The resin contained in the resin film 40 may be a polyimide-based polymer or a polyamide-based polymer. The polyimide-based polymer is, for example, a condensation-type polyimide obtained by polycondensation using diamines and tetracarboxylic dianhydride as starting materials. As the polyimide, a solvent soluble in a resin film can be selected. For example, those described in Japanese Patent Laid-Open No. 2016-93992 can be cited. In addition, polyamidide or polyamidimide can also be preferably used. Examples of the polyamide include those described in Japanese Patent Laid-Open No. 2011-12255. Examples of the polyimide amide imine include those described in WO2018/135431 or Japanese Patent Publication No. 2014-528490.

The resin film 40 may further contain inorganic materials such as inorganic particles. The inorganic material is preferably a silicon material containing silicon atoms. By making the resin film 40 contain an inorganic material such as a silicon material, the tensile elastic modulus of the resin film 40 can be easily made 4.0 GPa or more. However, the method of controlling the tensile modulus of the resin film 40 is not limited to the formulation of inorganic materials.

Examples of the silicon material containing silicon atoms include silicon compounds such as silicon dioxide particles, tetraethylorthosilicate (TEOS) and other quaternary alkoxysilanes, and silsesquioxane derivatives. Among these silicon materials, from the viewpoint of the transparency and flexibility of the resin film 40, silicon dioxide particles are preferred.

The average primary particle size of silica particles is usually below 100 nm. If the average primary particle size of the silica particles is 100 nm or less, the transparency tends to increase.

The average primary particle diameter of the silica particles in the resin film can be obtained by observation through a transmission electron microscope (TEM). The primary particle size of the silicon dioxide particles can be set to a fixed diameter obtained by transmission electron microscopy (TEM). The average primary particle diameter is measured by TEM observation to measure the primary particle diameter at 10 points, and is obtained as the average value of these. The particle size distribution of the silica particles before forming the resin film can be obtained by a commercially available laser diffraction particle size distribution meter.

In the resin film 40, as the compounding ratio of the polyimide-based polymer or the polyamide-based polymer and the inorganic material, the total of the two is set to 10, and the mass ratio is preferably 1:9 to 10: 0, more preferably 3:7 to 10:0, still more preferably 3:7 to 8:2, still more preferably 3:7 to 7:3. The ratio of the inorganic material relative to the total mass of the polyimide-based polymer or the polyamide-based polymer and the inorganic material is usually 20% by mass or more, preferably 30% by mass or more, and usually 90% by mass or less, preferably 70% by mass or less. If the blending ratio of the polyimide-based polymer or the polyamide-based polymer and the inorganic material (silicon material) is within the above range, there is a tendency for the transparency and mechanical strength of the resin film to increase. In addition, the tensile modulus of elasticity of the resin film 40 can be easily made 4.0 GPa or more.

The resin film 40 may further contain components other than the polyimide-based polymer or the polyamide-based polymer and the inorganic material within a range that does not significantly impair transparency and flexibility. Examples of components other than polyimide-based polymers, polyamide-based polymers, and inorganic materials include colorants such as antioxidants, mold release agents, stabilizers, and blueing agents, flame retardants, lubricants, Tackifier and leveling agent. The ratio of the components other than the polyimide-based polymer or the polyamide-based polymer and the inorganic material to the mass of the resin film 40 is preferably more than 0% and 20% by mass or less, and more preferably more than 0% and 10% by mass or less.

When the resin film 40 contains a polyimide-based polymer or a polyamide-based polymer and a silicon material, the Si/N ratio of the atomic ratio of silicon atoms to nitrogen atoms on at least one main surface 40a is preferably 8 or more. The atomic ratio Si/N is calculated by X-ray photoelectron spectroscopy (XPS) to evaluate the composition of the main surface 10a, and is calculated from the amount of silicon atoms and the amount of nitrogen atoms obtained from this value.

By setting the Si/N of the main surface 40a of the resin film 40 to 8 or more, sufficient adhesion with the functional layer 50 described below can be obtained. From the viewpoint of adhesion, Si/N is more preferably 9 or more, and further preferably 10 or more, preferably 50 or less, and more preferably 40 or less.

The thickness of the resin film 40 is suitably adjusted according to the soft device applying the front panel (4), and is usually 10 to 500 μm, preferably 15 to 200 μm, more preferably 20 to 100 μm, and still more preferably 30 to 100 μm. The thickness of the resin film 40 is particularly preferably 40 to 100 μm, most preferably 40 to 90 μm, and 30 to 70 μm. The resin film 40 having such a structure has particularly excellent flexibility and practically sufficient strength.

Next, an example of a method of manufacturing the resin film 40 of this embodiment will be described. The polyimide-based polymer varnish used in the manufacture of the resin film is a solvent-soluble polyimide-based polymer polymerized by a known synthesis method of the polyimide-based polymer is dissolved in the solvent While preparing. The solvent may be any solvent that dissolves the polyimide-based polymer, and examples include N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), and dimethyl Kiya (DMSO), γ-butyrolactone (GBL) and mixed solvents of these.

In the case of manufacturing a resin film containing an inorganic material, an inorganic material is added to a polyimide-based polymer varnish, and stirring and mixing are performed by a known stirring method to prepare a dispersion liquid in which the silicon material is uniformly dispersed. In the case of formulating an ultraviolet absorber, an ultraviolet absorber can be added to the dispersion.

The polyimide-based polymer varnish or dispersion liquid may contain metal alkoxides such as alkoxysilanes that facilitate the bonding of inorganic particles (silica particles, etc.) to each other. By using a dispersion liquid containing such a compound, optical properties such as transparency of the resin film can be maintained, and the mixing ratio of inorganic particles can be increased. The compound is preferably an alkoxysilane having an amine group. This combination of compound and inorganic particles can achieve a higher modulus of elasticity, and also helps to increase the number of bending times until the resin film breaks during the bending test.

The polyimide-based polymer varnish or dispersion liquid may further contain water. The content of water is usually 0.1 to 10% by mass relative to the mass of the polyimide-based polymer varnish or dispersion. The use of water can also achieve a higher modulus of elasticity and increase the number of bending times until the resin film breaks in the bending test.

The polyimide-based polymer or dispersion may further contain additives. Examples of additives include colorants such as antioxidants, mold release agents, stabilizers, and blueing agents, flame retardants, lubricants, thickeners, and leveling agents.

The resin film can be produced by a suitable well-known method. As an example of the manufacturing method, the following method may be mentioned. The above-mentioned polyimide-based polymer varnish or dispersion liquid is applied to a substrate by, for example, a known roll-to-roll or batch method to form a coating film. The coating film is dried to form a film. Thereafter, the film is peeled from the substrate, thereby obtaining the resin film 10. Examples of the substrate include polyethylene terephthalate (PET) substrate, stainless steel (SUS) tape, and glass substrate.

In order to dry and/or bake the coating film, the coating film is heated. The heating temperature of the coating film is usually 50 to 350°C. The heating of the coating film can be carried out under an inert environment or under reduced pressure. By heating the coating film, the solvent can be evaporated and removed. The resin film can be formed by a method including a step of drying the coating film at 50 to 150°C and a step of baking the dried coating film at 180 to 350°C.

At least one main surface of the resin film may be subjected to surface treatment. The surface treatment is preferably UV ozone treatment. By UV ozone treatment, Si/N can be easily made 8 or more. However, the method of making Si/N 8 or more is not limited to UV ozone treatment. In order to improve the adhesion with the following functional layer, the main surface 10a and/or 10b of the resin film 10 may be subjected to surface treatment such as plasma treatment or corona discharge treatment.

The UV ozone treatment can be performed using a well-known ultraviolet light source including a wavelength of 200 nm or less. Examples of ultraviolet light sources include low-pressure mercury lamps. As the ultraviolet light source, various commercially available devices equipped with an ultraviolet light source can be used. As a commercially available device, for example, an ultraviolet (UV) ozone cleaning device UV-208 manufactured by TECHNOVISION Corporation can be cited.

The tensile elastic modulus of the resin film 40 at 25° C. is, for example, 4.0 GPa or more, preferably 5 GPs or more, more preferably more than 5 GPa, and more preferably 10 GPa or less, more preferably 8 GPa or less. By making the tensile modulus of elasticity within these numerical ranges, in addition to improving the surface hardness, excellent effects can also be obtained in terms of bending recovery.

In the bending test in which the operation of bending the resin film 40 into a U shape until the distance between the opposing resin films becomes 3 mm (radius 1.5 R) and recovering is repeated, the resin film 10 is bent until the resin film 40 breaks The number of bending times so far is preferably more than 100,000 times. In the bending test, the so-called "resin film breakage" refers to the partial or whole breakage of the resin film, that is, the portion where breakage occurs in the entire thickness direction. When the resin film is not broken when the number of bending times reaches 100,000 times, it is considered that the number of bending times until the resin film breaks exceeds 100,000 times. According to the findings of the present inventors and others, based on the bending test up to 100,000 bending times, the effect of the resin film on the improvement of the surface hardness can be evaluated. The details of the bending test are described in the following examples.

The yellowness (YI value) of the resin film 40 is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less from the viewpoint of visibility of the flexible device. The yellowness of the resin film 40 is usually 0.5 or more, and may be 1 or more. (Functional layer) The front panel (4) may include a resin film 40 and a functional layer 50 laminated on at least one main surface 40a of the resin film 40.

The functional layer 50 is preferably a layer having at least one function selected from the group consisting of ultraviolet light absorption, a function to make the surface express high hardness, hue adjustment, and refractive index adjustment.

The layer having an ultraviolet absorbing function (ultraviolet absorbing layer) as the functional layer 50 includes, for example, a main material selected from the group consisting of ultraviolet curing type transparent resin, electron beam curing type transparent resin, and thermosetting type transparent resin, and dispersed in UV absorber in the main material. By providing an ultraviolet absorbing layer as the functional layer 50, the change in yellowness due to light irradiation can be easily suppressed.

The ultraviolet curing type, electron beam curing type or thermosetting type transparent resin as the main material of the ultraviolet absorption layer is not particularly limited, and examples thereof include poly(meth)acrylate and the like.

The ultraviolet absorption layer may be a layer that absorbs more than 95% of light with a wavelength of 400 nm or less (for example, light with a wavelength of 313 nm). In other words, the ultraviolet absorbing layer may be a layer having a transmittance of less than 5% for light with a wavelength below 400 nm (for example, light with a wavelength of 313 nm). The ultraviolet absorbing layer may contain an ultraviolet absorbing agent at a concentration that can achieve such transmittance. From the viewpoint of suppressing the increase in yellowness of the front panel due to light irradiation, the ratio of the content of the ultraviolet absorber in the ultraviolet absorption layer (functional layer 50) is generally 1% by mass or more based on the mass of the ultraviolet absorption layer It is preferably 3% by mass or more, usually 10% by mass or less, and preferably 8% by mass or less.

As the functional layer 50, a functional layer (hard coat layer) that exhibits high hardness on the surface is, for example, a layer that provides a surface having a pencil hardness higher than that of the resin film surface to the laminate. The hard coat layer is not particularly limited, and includes an active energy ray hardening type or thermosetting type radical hardening composition or cationic hardening composition represented by poly(meth)acrylates. The hard coat layer may contain a photopolymerization initiator and an organic solvent. As the radical hardening composition, poly(meth)acrylates are preferred, for example, selected from poly(meth)acrylate urethane, epoxy (meth)acrylate and other multifunctional poly(meth)acrylates. Poly(meth)acrylates formed from one or more (meth)acrylates of acrylates. The cationic hardening composition includes a compound having a cationic polymerizable group such as an epoxy group, an oxetanyl group, and a vinyl ether group. It is preferably a polyfunctional compound having two or more cationic polymerizable groups in the molecule. In addition to the above components, the hard coat layer may also contain inorganic oxides such as silica, alumina, polyorganosiloxane, and the like. The pencil hardness of the functional layer (hard coat layer) that makes the surface express high hardness is preferably 2 H or more, and more preferably 3 H or more.

The layer having a hue adjustment function (hue adjustment layer) as the functional layer 50 can adjust the front panel (4) to the target hue. The hue adjustment layer may be, for example, a layer containing resin and coloring agent. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, red lead, oxytitanium-based calcined pigments, ultramarine blue, cobalt aluminate, and carbon black; azo-based compounds, quinacridone-based compounds, and anthraquinone-based compounds Organic pigments such as compounds, perylene-based compounds, isoindolinone-based compounds, phthalocyanine-based compounds, quinophthalone-based compounds, threne compounds, and pyrrolopyrrole-dione-based compounds; constitutions such as barium sulfate and calcium carbonate Pigments; dyes such as basic dyes, acid dyes and mordant dyes.

The layer having a refractive index adjustment function (refractive index adjustment layer) as the functional layer 50 is a layer having a refractive index different from that of the resin film 40 and can impart a specific refractive index to the laminate. The refractive index adjustment layer may be, for example, a resin layer containing a suitably selected resin, and optionally a pigment, or a metal thin film.

Examples of the pigments for adjusting the refractive index include silicon oxide, aluminum oxide, antimony oxide, tin oxide, titanium oxide, zirconium oxide, and tantalum oxide. The average particle diameter of the pigment is preferably 0.1 μm or less. By setting the average particle diameter of the pigment to 0.1 μm or less, it is possible to prevent the diffuse reflection of the light passing through the refractive index adjustment layer and prevent the decrease in transparency.

Examples of the metal used in the refractive index adjustment layer include titanium oxide, tantalum oxide, zirconium oxide, zinc oxide, tin oxide, silicon oxide, indium oxide, titanium oxynitride, titanium nitride, silicon oxynitride, and nitride Metal oxides or metal nitrides such as silicon.

The functional layer 50 preferably has the above-mentioned functions according to the purpose of the front panel (4). The functional layer 50 may be a single layer or a plurality of layers. Each layer can have one function or more than two functions.

The functional layer 50 preferably has a function to make the surface express high hardness and an ultraviolet absorption function. In this case, the functional layer 50 preferably includes a "single layer having a function of giving high hardness to the surface and an ultraviolet absorbing function", and a "multilayer comprising a layer having a function of making the surface have high hardness and a layer having an ultraviolet absorbing function" "Or "multilayers consisting of a single layer with a function to make the surface express high hardness and an ultraviolet absorption function and a layer with high hardness".

The thickness of the functional layer 50 is appropriately adjusted according to the soft device of the front panel (4), preferably 1 μm-100 μm, more preferably 1 μm-80 μm. Furthermore, it is preferably 1 μm to 30 μm, and more preferably 1 μm to 20 μm. The functional layer 50 is typically thinner than the resin film 40.

The front panel (4) can be obtained by forming the functional layer 50 on the main surface 40a of the resin film 40. The functional layer 50 can be formed by a well-known roll-to-roll or batch method.

The ultraviolet absorbing layer as the functional layer 50 can be formed, for example, by coating the main surface 40a of the resin film 10 with a dispersion liquid containing a main material such as an ultraviolet absorber and a resin that disperses the ultraviolet absorber to form a coating film. The coating film is dried and hardened.

The hard coat layer as the functional layer 50 can be formed by, for example, a method in which a solution containing a resin for forming a hard coat layer is applied to the main surface 40a of the resin film 40 to form a coating film, and the coating film is dried and cured.

The hue adjustment layer as the functional layer 50 can be formed, for example, by coating the main surface 40a of the resin film 40 with a dispersion liquid containing a pigment and other main materials for forming the hue adjustment layer and dispersing the pigment and the like to form a coating Film to dry and harden the coating.

The refractive index adjustment layer as the functional layer 50 can be formed, for example, by coating the main surface 40a of the resin film 40 with the dispersion of the main material such as the inorganic particles forming the refractive index adjustment layer and the resin dispersing the inorganic particles, etc. Liquid to form a coating film, and the coating film is dried and hardened.

As the functional layer 50, a single layer having a function of exhibiting high hardness on the surface and an ultraviolet absorption function can be formed by coating the main surface 40a of the resin film 40 with a resin containing an ultraviolet absorber, a resin that disperses the ultraviolet absorber, etc. The dispersion of the material and the resin forming the hard coat layer forms a coating film, and the coating film is dried and hardened. The resin used as the main material and the resin forming the hard coat layer may be the same.

A multi-layer functional layer including a layer having a function to make the surface exhibit high hardness and a layer having an ultraviolet absorption function can be formed by the following method. The main film 40 a of the resin film 40 is coated with a dispersion liquid containing a main material such as an ultraviolet absorber and a resin that disperses the ultraviolet absorber to form a coating film, and the coating film is dried and hardened to form an ultraviolet absorption layer. Then, a solution containing a resin forming a hard coat layer is coated on the ultraviolet absorbing layer to form a coating film, and the coating film is dried and hardened, whereby a hard coat layer can be formed. By this method, a multi-layer functional layer including a layer having a function of making the surface express high hardness and a layer having an ultraviolet absorption function is formed.

The functional layer including a single layer having a function of making the surface express high hardness and an ultraviolet absorbing function and a multilayer of the layer showing high hardness can be formed by the following method. The main surface 40a of the resin film 40 is coated with a dispersion liquid of a main material containing an ultraviolet absorber, a resin that disperses the ultraviolet absorber, and a resin forming a hard coat layer to form a coating film, and the coating film is dried and cured to form A single layer that exhibits a function of high hardness and ultraviolet absorption on the surface, and further, a solution containing a resin forming a hard coat layer is coated on the single layer to form a coating film, and the coating film is dried and hardened, thereby forming Hard coating. By this method, a multi-layer functional layer including a layer having a function of giving high hardness to the surface and an ultraviolet absorbing function and a layer having a function of making the surface show high hardness is formed.

The front panel (4) of this embodiment thus obtained is excellent in flexibility, and can have such functionalities as transparency, ultraviolet resistance, and the function of making the surface have high hardness required when applied to the front panel. As the front panel (4), when the Si/N in the main surface 40a of the resin film 40 is 8 or more, the adhesion between the resin film 40 and the functional layer 50 is also excellent. Furthermore, in the case where the functional layer 50 is a layer (hard coat layer) having a function of making the surface exhibit high hardness, the functional layer 50 can have a high surface hardness.

Fig. 5 is also a cross-sectional view showing an embodiment of the front panel. The front panel (4) shown in FIG. 5 has an undercoat layer 45 provided between the resin film 40 and the functional layer 40 in addition to the same resin film 40 and functional layer 50 as the front panel of FIG. 4. The undercoat layer 45 is deposited on one main surface 40 a of the resin film 40. The functional layer 50 is laminated on the main surface 45a of the primer layer 45 on the side opposite to the main surface of the contact resin film 40.

The undercoat layer 45 is a layer formed of an undercoating agent, and preferably contains a material that can improve the adhesion with the resin film 40 and the functional layer 50. The compound contained in the undercoat layer 45 can chemically bond with the polyimide-based polymer or silicon material contained in the resin film 40 at the interface.

Examples of the primer include an ultraviolet curing type, thermosetting type or two-component curing type epoxy type compound primer. The primer may be polyamide. These primers can be preferably used to improve the adhesion with the resin film 40 and the functional layer 50.

The primer may contain a silane coupling agent. The silane coupling agent can chemically bond with the silicon material contained in the resin film 40 through a condensation reaction. The silane coupling agent can be preferably used in the case where the silicon material contained in the resin film 40 has a high compounding ratio.

Examples of the silane coupling agent include compounds having an alkoxysilyl group having a silicon atom and 1 to 3 alkoxy groups covalently bonded to the silicon atom. A compound containing a structure in which two or more alkoxy groups are covalently bonded to a silicon atom is preferable, and a compound containing a structure in which three alkoxy groups are covalently bonded to a silicon atom is more preferable. Examples of the alkoxy group include methoxy, ethoxy, isopropoxy, n-butoxy, and third butoxy groups. Among them, methoxy and ethoxy can improve the reactivity with silicon materials, so it is preferred.

The silane coupling agent preferably has a substituent having a high affinity with the resin film 40 and the functional layer 50. From the viewpoint of affinity with the polyimide-based polymer contained in the resin film 40, the substituent of the silane coupling agent is preferably an epoxy group, an amine group, a urea group, or an isocyanate group. In the case where the functional layer 50 contains (meth)acrylates, if the silane coupling agent used in the undercoat layer 45 has an epoxy group, a methacrylic group, an acrylic group, an amine group or a styrene group, the affinity Sex is improved, so it is better. Among these, the silane coupling agent having a substituent selected from a methacrylic group, an acrylic group, and an amine group tends to show excellent affinity with the resin film 40 and the functional layer 50, and is therefore preferable.

The thickness of the undercoat layer 45 is appropriately adjusted according to the functional layer 50, and is preferably 0.01 nm to 20 μm. When an epoxy-based compound primer is used, the thickness of the primer layer 45 is preferably 0.01 μm to 20 μm, and more preferably 0.1 μm to 10 μm. In the case of using a silane coupling agent, the thickness of the primer layer 45 is preferably 0.1 nm to 1 μm, and more preferably 0.5 nm to 0.1 μm.

The front panel (4) of FIG. 5 can be manufactured by, for example, a method including the following: applying a solution in which a primer is dissolved to the main surface 40a of the resin film 40 to form a coating film, and drying and hardening the formed coating film Form a primer layer. The forming method of other components is the same as the front panel (4) of FIG. 4. The undercoat layer 45 may be hardened at the same time as the functional layer 50, or may be hardened separately before the functional layer 50 is formed.

The front panel has high transparency and maintains excellent visibility when bent. In addition, the front panel can also have excellent flexibility. In addition, when an undercoat layer is provided between the resin film and the functional layer, the adhesion between the resin film and the functional layer becomes high. The front panel may have functionalities such as transparency, ultraviolet resistance, and surface hardness required in the case of an optical member or a display member substrate of a flexible device or a front panel.

The composition of the front panel can be changed appropriately. For example, as shown in the front panel (4) of FIG. 6, functional layers may be provided on both sides of the resin film. In this case, an undercoat layer may be provided between each functional layer and the resin film.

<Phase difference film> The polarizing plate may be provided with a retardation film on the side opposite to the front panel side of the polarizing element. As shown in FIG. 2, the polarizing plate may be provided with a retardation film (5) on the side opposite to the polarizing element side of the diffusion prevention layer (B). In addition, when the polarizing plate is provided with an adhesive layer, the polarizing plate may be provided with a retardation film on the opposite side of the adhesive layer from the anti-diffusion layer side. The polarizing plate may have both a front panel and a retardation film. The above-mentioned polarizing plate with a front panel may be provided with a retardation film on the opposite side of the anti-diffusion layer from the polarizing element side.

The retardation film preferably includes a birefringence Δn (λ) that exhibits the retardation expressed by the following formulas (1-1) and (2-1) and the following formula (3) for light with a wavelength of λ nm λ/4 phase difference plate. Δn(450)/Δn(550)≦1.00 (1-1) 1.00≦Δn(650)/Δn(550) (2-1) 120 nm≦Re(550)≦180 nm (3)

Δn(450), Δn(550), Δn(650) represent the birefringence at wavelengths 450 nm, 550 nm, and 650 nm, respectively.

The birefringence Δn(λ) can be obtained by measuring the in-plane retardation and dividing by the thickness of the retardation film. The specific measurement method is shown in the examples. In this case, the characteristics of the substantial retardation film can be measured by measuring the film formed on the substrate without delay such as the glass substrate itself. That is, the retardation film is preferably a retardation film exhibiting retardation expressed by the following formulas (1) and (2) and the above formula (3). Re(450)/Re(550)≦1.00 (1) 1.00≦Re(650)/Re(550) (2)

Re(450), Re(550), Re(650) represent in-plane retardation at wavelengths 450 nm, 550 nm, and 650 nm, respectively. The retardation film may be a single layer or a multilayer film. When the retardation film is a multilayer film, each film can be bonded using the above-mentioned adhesive or the following adhesive. Moreover, each film can also be directly formed by a method such as coating the composition for forming each film.

[Adhesive] As the adhesive, water-based adhesives, organic solvent-based, solvent-free adhesives, solid adhesives, solvent-evaporable adhesives, moisture-curing adhesives, heat-curing adhesives, anaerobic curing-type, active Energy ray-curable adhesives, hardener-mixed adhesives, hot-melt adhesives, pressure-sensitive adhesives (adhesives), rewet adhesives, etc. are commonly used by users. Among them, water-based solvent evaporative adhesives, active energy ray hardening adhesives, and adhesives are more commonly used. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive force, etc., and is 0.01 μm to 500 μm, preferably 0.1 μm to 300 μm, and there are a plurality of adhesive layers in the laminate for the flexible image display device The thickness of each type can be the same or different.

As the above-mentioned water-based solvent evaporative adhesive, water-soluble polymers such as polyvinyl alcohol-based polymers, starch and other water-soluble polymers, ethylene-vinyl acetate-based emulsions, and styrene-butadiene-based emulsions can be used as main components Agent polymer. In addition to water and the above-mentioned main polymer, crosslinking agents, silane compounds, ionic compounds, crosslinking catalysts, antioxidants, dyes, pigments, inorganic fillers, organic solvents, etc. can also be formulated. In the case of adhesion by the above-mentioned water-based solvent evaporative adhesive, the above-mentioned water-based solvent evaporative adhesive is injected into the layer to be adhered, and after the layer to be adhered is dried, the adhesiveness can be imparted. In the case of using the above-mentioned water-based solvent scattering adhesive, the thickness of the adhesive layer may be 0.01 to 10 μm, preferably 0.1 to 1 μm. In the case of using a plurality of layers of the above-mentioned aqueous solvent-scattering adhesive, the thickness of each layer may be the same or different.

The active energy ray hardening type adhesive can be formed by hardening an active energy ray hardening composition containing a reactive material that forms an adhesive layer by irradiation with active energy rays. The active energy ray hardening composition may contain at least one polymer of the same radical polymerizable compound and cationic polymerizable compound as the hard coating composition. The radical polymerizable compound is the same as the hard coating composition, and the same kind as the hard coating composition can be used. As the radical polymerizable compound used for the adhesive layer, a compound having an acryloyl group is preferred. In order to reduce the viscosity of the adhesive composition, it is also preferable to contain a monofunctional compound.

The cationic polymerizable compound is the same as the hard coating composition, and the same kind as the hard coating composition can be used. As the cationic polymerizable compound used in the active energy ray hardening composition, an epoxy compound is particularly preferred. In order to reduce the viscosity of the adhesive composition, it is also preferable to contain a monofunctional compound as a reactive diluent.

The active energy ray composition may further contain a polymerization initiator. As the polymerization initiator, there are a radical polymerization initiator, a cationic polymerization initiator, a radical and a cationic polymerization initiator, etc., which can be appropriately selected and used. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate free radicals or cations to perform free radical polymerization and cation polymerization. An initiator that can initiate at least any one of radical polymerization or cationic polymerization by active energy ray irradiation in the description of the hard coating composition can be used.

The active energy ray hardening composition may further contain an ion scavenger, an antioxidant, a chain transfer agent, an adhesion-imparting agent, a thermoplastic resin, a filler, a fluid viscosity adjuster, a plasticizer, a defoamer solvent, an additive, and a solvent. In the case of bonding by the above-mentioned active energy ray-curable adhesive, the above-mentioned active energy ray-curable composition is applied to any one or both of the adhered layers, and then pasted through either adhered layer or both The adhered layer is irradiated with active energy rays to harden it, whereby it can be adhered. In the case of using the above active energy ray-curable adhesive, the thickness of the adhesive layer may be 0.01-20 μm, preferably 0.1-10 μm. In the case of using a plurality of layers of the above-mentioned active energy ray-curable adhesive, the thickness of each layer may be the same or different.

The above-mentioned adhesives are classified into acrylic adhesives, urethane adhesives, rubber adhesives, polysiloxane adhesives, etc. according to the main polymer, and any of them can be used. In addition to the main agent polymer, crosslinking agents, silane-based compounds, ionic compounds, crosslinking catalysts, antioxidants, adhesion-imparting agents, plasticizers, dyes, pigments, inorganic fillers, etc. can also be formulated in the adhesive. Each component constituting the above-mentioned adhesive is dissolved and dispersed in a solvent to obtain an adhesive composition, and the adhesive composition is coated on a substrate and then dried, thereby forming an adhesive layer adhesive layer. The adhesive layer can be formed directly, or it can be transferred to those formed on the substrate. In order to cover the adhesive surface before bonding, the case where a release film is used is also preferable. In the case of using the above-mentioned active energy ray-curable adhesive, the thickness of the adhesive layer may be 0.1 to 500 μm, preferably 1 to 300 μm. In the case of using multiple layers of the above-mentioned adhesive, the thickness of each layer may be the same or different.

Furthermore, the retardation film preferably includes the aforementioned λ/4 retardation plate. The aforementioned λ/4 retardation plate is a film that imparts λ/4 retardation in a direction orthogonal to the traveling direction of incident light (in-plane direction of the film). The polarizing plate is preferably such that the polarizing element and the retardation film are arranged such that the angle formed by the absorption axis of the polarizing element and the slow phase axis of the λ/4 retardation plate becomes 45°±10°. By setting such an axis angle, the polarizing plate can function as a circular polarizing plate.

The λ/4 retardation plate may be an extended retardation plate manufactured by stretching a polymer film such as a cellulose-based film, an olefin-based film, and a polycarbonate-based film. May contain phase difference adjuster, plasticizer, ultraviolet absorber, infrared absorber, coloring agent such as pigment or dye, fluorescent whitening agent, dispersant, heat stabilizer, light stabilizer, antistatic agent, Antioxidants, lubricants, solvents, etc. The thickness of the extended retardation plate may be 200 μm or less, preferably 1 μm to 100 μm. If the thickness exceeds 200 μm, the flexibility may decrease.

Furthermore, as another example of the aforementioned λ/4 retardation plate, a liquid crystal coating type retardation plate formed by coating a liquid crystal composition may be used. The liquid crystal composition contains a liquid crystal compound having a property of showing a liquid crystal state such as nematic, cholesteric, and smectic. Any compound in the liquid crystal composition containing a liquid crystal compound has a polymerizable functional group. The liquid crystal coating type retardation film may further contain an initiator, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. The above-mentioned liquid crystal coating type retardation plate can be manufactured in the same manner as described in the above-mentioned liquid crystal polarizing layer: a liquid crystal composition is coated on the alignment film and cured to form a liquid crystal retardation layer. The liquid crystal coating type retardation plate can be formed with a thinner thickness than the extended type retardation plate. The thickness of the liquid crystal coating type retardation plate may be 0.5 to 10 μm, preferably 1 to 5 μm. The liquid crystal coating type retardation plate may be peeled off from the substrate and transferred to be laminated, or the substrate may be directly laminated. The above substrate is also preferably used as a protective film, a phase difference plate, or a transparent substrate of the front panel.

Generally speaking, the shorter the wavelength, the greater the birefringence, and the longer the wavelength, the smaller the birefringence. In this case, the λ/4 phase difference cannot be achieved in the entire visible light region. Therefore, in the vicinity of 560 nm, where the visual sensitivity is high, the in-plane phase difference of λ/4 becomes 100-180 nm, preferably There are many situations in the way of designing from 130 to 150 nm. In the case of using an inverse dispersion λ/4 retardation plate using a material having a birefringence wavelength dispersion characteristic opposite to that of usual, the visibility is improved, which is preferable. As such a material, in the case of an extended phase difference plate, the one described in Japanese Patent Laid-Open No. 2007-232873, etc. is used, and in the case of a liquid crystal coating type phase difference plate, the Japanese Patent Laid-Open No. 2010-30979 is used The situation described in the bulletin is also preferable.

As another method, a technique of obtaining a wide-band λ/4 phase difference plate by combining a λ/2 phase difference plate is also known (Japanese Patent Laid-Open No. 10-90521). The λ/2 phase difference plate is also manufactured by the same material method as the λ/4 phase difference plate. The combination of the extended type retardation plate and the liquid crystal coating type retardation plate is arbitrary, and when both use the liquid crystal coating type retardation plate, the thickness can be made thinner, which is preferable.

A method of stacking a positive C plate on a polarizing plate to improve visibility in an oblique direction is also known (Japanese Patent Laid-Open No. 2014-224837). The positive C plate may also be a liquid crystal coating type retardation plate or an extension type retardation plate. The phase difference in the thickness direction is -200 to -20 nm, preferably -140 to -40 nm.

[Touch Sensor] The touch sensor may be disposed between the front panel and the polarizing plate, or on the opposite side of the phase difference film from the polarizing plate, etc., which is suitable for maintaining optical characteristics or functions of the touch panel. From the viewpoint of suppressing the reflected light from the touch sensor electrode, the touch sensor is preferably arranged on the opposite side of the phase difference film from the polarizing plate side, but it is not limited thereto. As shown in FIG. 3, the polarizing plate with a front panel can be provided with a touch sensor (6) on the opposite side of the phase difference film (5) from the polarizing plate. Moreover, the phase difference film and the touch sensor can be laminated through an adhesive layer.

The touch sensor is used as an input mechanism. As the touch sensor, various types such as a resistive film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and an electrostatic capacitance method are proposed, and any method can be used. Among them, the electrostatic capacitance method is preferred. The electrostatic capacitance type touch sensor is divided into an active area and an inactive area located outside the outline of the active area. The active area is the area corresponding to the area (display section) of the display screen in the display panel, and is the area that senses the user's touch, and the inactive area is the area corresponding to the area (non-display section) of the display device where the screen is not displayed. The touch sensor may include: a substrate having soft characteristics; a sensing pattern formed in the active area of the substrate; an inactive area formed on the substrate and used to separate the sensing pattern and the pad portion from the outside Each sensing line connected to the driving circuit. As the substrate having soft characteristics, the same material as the resin film of the above-mentioned front panel can be used. As the substrate of the touch sensor, in terms of crack suppression of the touch sensor, the toughness is preferably 2,000 MPa% or more. More preferably, the toughness may be 2,000 to 30,000 MPa%.

The sensing pattern may include a first pattern formed in the first direction and a second pattern formed in the second direction. The first pattern and the second pattern are arranged in mutually different directions. The first pattern and the second pattern are formed on the same layer. In order to perceive the touch location, each pattern must be electrically connected. The first pattern is a form in which each unit pattern is connected to each other via a joint, and the second pattern is a structure in which each unit pattern is separated from each other into an island shape. Therefore, in order to electrically connect the second pattern, a separate bridge electrode is required. As the sensing pattern, a well-known transparent electrode material can be applied. For example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), PEDOT (poly(3,4 -ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)), carbon nanotubes (CNT), graphene, metal wires, etc. These can be used alone or in combination of two or more. Preferably, ITO can be used. The metal used in the metal wire is not particularly limited, and examples thereof include silver, gold, aluminum, copper, iron, nickel, titanium, selenium, and chromium. These can be used alone or in combination of two or more.

The bridge electrode may be formed on the insulating layer above the sensing pattern via the insulating edge layer, and the bridge electrode may be formed on the substrate on which the insulating layer and the sensing pattern are formed. The above-mentioned bridge electrode can be formed by the same material as the sensing pattern, or by metals such as molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or two or more of these alloys While forming. The first pattern and the second pattern must be electrically insulated, so an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer may be formed only between the joint of the first pattern and the bridge electrode, or may be formed as a layer covering the sensing pattern. In the latter case, the bridge electrode may be connected to the second pattern via the contact hole formed in the insulating layer. The above-mentioned touch sensor may further include an optical adjustment layer between the substrate and the electrode as a means for appropriately compensating for the difference in transmittance between the patterned patterned area and the unpatterned non-patterned area, specifically because of these The mechanism of the difference in light transmittance induced by the difference in refractive index in the region, the optical adjustment layer may contain an inorganic insulating substance or an organic insulating substance. The optical adjustment layer can be formed by coating a photo-curable composition containing a photo-curable organic binder and a solvent on a substrate. The photocurable composition may further contain inorganic particles. The above-mentioned inorganic particles can increase the refractive index of the optical adjustment layer. The photocurable organic binder may contain, for example, a copolymer of monomers such as acrylate monomers, styrene monomers, and carboxylic acid monomers. The photocurable organic binder may be, for example, a copolymer containing repeating units different from each other, such as an epoxy-containing repeating unit, an acrylate repeating unit, and a carboxylic acid repeating unit. The inorganic particles may contain, for example, zirconia particles, titania particles, alumina particles, and the like. The photocurable composition may further contain various additives such as a photopolymerization initiator, a polymerizable monomer, and a curing aid.

The polarizing plate with front panel can be used for various display devices. The so-called display device refers to a device having a display element, including a light-emitting element or a light-emitting device as a light-emitting source. Examples of display devices include liquid crystal display devices, organic electroluminescence (EL) display devices, inorganic electroluminescence (EL) display devices, touch panel display devices, and electron emission display devices (such as field emission display devices (FED)) , Surface field emission display device (SED)), electronic paper (display device using electronic ink or electrophoretic elements), plasma display device, projection display device (such as grid light valve imaging system (GLV) display device, with Digital micromirror device (DMD) display device) and piezoelectric ceramic displays. The liquid crystal display device also includes any one of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, and a projection liquid crystal display device. The display devices may be display devices that display two-dimensional images, or stereo display devices that display three-dimensional images. In particular, the polarizing plate and elliptical polarizing plate with a front panel can be effectively used in liquid crystal display devices and organic electroluminescence (EL) display devices.

[Soft image display device] In addition, the polarizing plate with a front panel has excellent flexibility, and therefore can be preferably used as a laminate for flexible image display devices. Examples of the flexible image display device include a laminate for a flexible image display device and an organic EL display panel. In the case of an organic EL display device, a layered body for a flexible image display device is arranged on the viewing side with respect to the organic EL display panel, and is configured to be bendable. In addition, the laminate for a flexible image display device may include a light-shielding pattern formed on at least one surface of any layer of the front panel, the polarizing plate, and the touch sensor.

(Shading pattern) The light-shielding pattern may be used as at least a part of a frame or a casing of the flexible image display device. The wiring arranged at the edge of the flexible image display device is hidden by the light-shielding pattern so that it is not easily recognized, thereby improving the visibility of the image. The light-shielding pattern may be in the form of a single layer or a plurality of layers. The color of the shading pattern is not particularly limited, and can have various colors such as black, white, and metallic colors. The light-shielding pattern can be formed by a pigment, an acrylic resin, an ester resin, an epoxy resin, a polyurethane, a polysiloxane, or other polymers for color development. These can be used alone or in the form of a mixture of two or more. The above-mentioned light-shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light-shielding pattern may be 1 μm to 100 μm, preferably 2 μm to 50 μm. In addition, it is also preferable to give a shape such as an inclination to the thickness direction of the light shielding pattern. [Example]

Hereinafter, the present invention will be further described in detail by examples, but the present invention is not limited by these examples. In the examples, "parts" means "parts by mass" unless otherwise specified. The evaluation method is as follows. (1) Flexibility test A polyethylene terephthalate (PET) film was laminated on the polarizing plate with front panel obtained in each of Examples and Comparative Examples via an adhesive layer 1 to obtain a polarizing plate/adhesive layer 1 including a front panel /PET film laminate. The thickness of PET film is analog display element, its thickness is 100 μm.

7 is a diagram schematically showing the method of the bendability test. A bending device (manufactured by Science Town, STS-VRT-500) equipped with two platforms 501 and 502 is prepared, and the laminate 100 is placed on the platforms 501 and 502 (FIG. 7a). The distance (clearance) C between the two platforms 501 and 502 is set to 3 mm (1.5 R). The platforms 501 and 502 can swing between two platforms (gap) C as a center. In the initial stage, the two platforms 501 and 502 constitute the same plane. Using position P1 and position P2 as the center of the rotation axis, rotate the two platforms 501, 502 upward by 90 degrees, close the two platforms 501, 502 (Figure 7b), open the platforms 501, 502 again, and define the above action as 1. Times bent. This operation was repeated, and the number of bends until the crack first occurred in the laminate 100 was counted.

The evaluation criteria are as follows. ◎(Excellent): 200,000 times or more 〇 (better): more than 100,000 times and less than 200,000 times △ (available): more than 50,000 times and less than 100,000 times × (Poor): more than 10,000 times and less than 50,000 times ××(poor): less than 10,000 times

The bendability test of the resin film constituting the front panel was performed by setting the distance (gap) C between the two platforms 501 and 502 in FIG. 7 to 3 mm (1.5 R). It is evaluated whether the number of bending times until the resin film is bent exceeds 100,000 times.

(2) Tensile elastic modulus The tensile elastic modulus is measured in accordance with JIS K7161 using UTM (Universal Testing Machine, Autograph AG-X, Shimadzu Corporation). The extension conditions were set to a speed of 1.5 mm/min, a width of 40 mm, and a gauge length of 50 mm at normal temperature (temperature 23°C).

(3) Heat resistance test The polarizing plates produced in the examples and comparative examples were bonded to the glass via the adhesive layer 2 to obtain a laminate including polarizing plate/adhesive layer 2/glass. Using a spectrophotometer (V7100, manufactured by Nippon Spectroscopy Co., Ltd.), the visual acuity correction polarization degree of the laminate was measured in the visible light region, and set as the visual acuity correction polarization degree [%] before the heat resistance test. Next, after the laminate was placed in an oven at a temperature of 85° C. for 500 hours, the visual acuity correction polarization degree was measured in the same manner, and it was set as the visual acuity correction polarization degree [%] after the heat resistance test. Based on the obtained correction degree of visual acuity, the absolute value of the amount of change in the correction degree of the visual acuity before and after the heat resistance test (|ΔP|) [%] is calculated.

The evaluation criteria are as follows. ◎(Excellent): Less than 3% 〇 (better): more than 3% and less than 5% △ (available): more than 5% and less than 7% × (Poor): more than 7% and less than 10% ××(Poor): 10% or more

(4) Yellowness The yellowness of the resin film is measured according to JIS K7373: 2006 by UV-Vis Near-Infrared Spectrophotometer V-670 manufactured by Japan Spectroscopy Co., Ltd. After background measurement without a resin film, the resin film is placed in the sample holder, and the transmittance of light with a wavelength of 300 to 800 nm is measured to obtain tristimulus values (X, Y, Z) . YI is calculated based on the following formula. YI＝100×(1.2769X－1.0592Z)/Y

(5) Storage modulus The storage modulus at a temperature of 25°C was measured using a viscoelasticity measuring device (MCR-301, Anton Paar). The same adhesive sheet as that used in the examples and comparative examples was made into a width of 30 mm × a length of 30 mm, and the peeling film was peeled off, and a plurality of sheets were stacked in such a way that the thickness became 150 μm. The wafer is measured in the temperature range of -20°C to 100°C under the conditions of frequency 1.0 Hz, deformation amount 1%, and heating rate 5°C/min. Confirm the measured value of the storage modulus at 25°C .

Prepare the following materials. (1) Front panel (1-1) Front panel 1: It includes a resin film containing a polyimide-based polymer, and a hard coat film formed on one main surface thereof. The thickness of the resin film is 50 μm, and the thickness of the hard coat layer is 10 μm. The number of bending times until the resin film breaks exceeds 100,000 times. The yellowness of the resin film is 1.2.

(1-2) Front panel 2: It includes a resin film containing polyethylene terephthalate and a hard coat film formed on one main surface thereof. The thickness of the resin film is 40 μm, and the thickness of the hard coat layer is 10 μm. The number of bending times until the resin film breaks exceeds 100,000 times. The yellowness of the resin film is 1.6.

(1-3) Front panel 3: It includes a resin film containing triethyl cellulose and a hard coat film formed on one main surface. The thickness of the resin film is 60 μm, and the thickness of the hard coat layer is 10 μm. The number of bends until the resin film broke did not reach 100,000. The yellowness of the resin film is 0.6.

將使該聚合物以濃度5重量%溶解於環戊酮中所得之溶液作為配向膜形成用組合物。(2) Composition for forming alignment film A polymer having a photoreactive group containing the following structural units is prepared.

A solution obtained by dissolving the polymer in cyclopentanone at a concentration of 5% by weight was used as a composition for forming an alignment film.

(3) Composition for forming polarizing element As the polymerizable liquid crystal compound, the compound (1-1) and the compound (1-2) represented by the following structures were used. Compound (1-1) and Compound (1-2) were synthesized by the method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996).

Compound (1-1)

Compound (1-2)

The compound (2-1a), compound (2-1b), and compound (2-3a) represented by the following structures were used as dichroic dyes.

(2-1a)Compound (2-1a)

(2-1a)

(2-1b)Compound (2-1b)

(2-1b)

(2-3a)Compound (2-3a)

(2-3a)

The composition for forming a polarizing element is prepared by: 75 parts by weight of compound (1-1), 25 parts by weight of compound (1-2), and the above formula (2-1a), (2 -1b), 2.5 parts by weight of each azo pigment represented by (2-3a), 2-dimethylamino-2-benzyl-1-(4-𠰌olinylphenyl) butyl as polymerization initiator 6 parts by weight of alkane-1-one (Irgacure369, BASF company), 1.2 parts by weight of polyacrylate compound (BYK-361N, BYK company) as a leveling agent were mixed with 400 parts by weight of toluene in the solvent, and the resulting mixture was mixed in Stir at 80°C for 1 hour.

(4) λ/4 phase difference plate The components shown below are mixed, and the resulting mixture is stirred at 80° C. for 1 hour, thereby obtaining a composition for forming a λ/4 retardation plate.

The compound represented by the following formula: 80 parts by weight

The compound represented by the following formula: 20 parts by weight

Polymerization initiator (Irgacure369, BASF company): 6 parts by weight Leveling agent (BYK-361N, polyacrylate compound, BYK company): 0.1 parts by weight Solvent (cyclopentanone): 400 parts by weight

Prepare a PET film with a thickness of 100 μm as the base material. The composition for forming an alignment film was coated on a PET film by a bar coating method, and heated and dried in a drying oven at 80° C. for 1 minute. The obtained coating film was subjected to polarized UV irradiation treatment to form an alignment film (AL2). The polarized UV treatment was performed using a UV irradiation device (SPOT CURE SP-7, manufactured by Niuwei Electric Co., Ltd.) under the condition that the cumulative light amount measured at a wavelength of 365 nm became 100 mJ/cm ² . In addition, the polarization direction of the polarized UV is 45° with respect to the absorption axis of the polarizing element.

The composition for forming a λ/4 retardation plate was coated on the alignment film (AL2) by a bar coating method, heated and dried in a drying oven at 120° C. for 1 minute, and then cooled to room temperature. Using the above-mentioned UV irradiation device, the obtained film was irradiated with ultraviolet rays with a cumulative light amount of 1000 mJ/cm ² (365 nm reference), thereby forming a λ/4 retardation plate. The thickness of the obtained λ/4 retardation plate was 2.0 μm.

(5) Positive C plate The components shown below are mixed, and the resulting mixture is stirred at 80° C. for 1 hour, thereby obtaining a composition for forming a positive C plate.

Compound represented by the following formula (LC242, manufactured by BASF): 100 parts by weight

Polymerization initiator (Irgacure907, 2-methyl-4'-(methylthio)-2-𠰌linyl phenylacetone, BASF): 2.6 parts by weight Leveling agent (BYK-361N, polyacrylate compound, BYK company): 0.5 parts by weight Additive (LR9000, BASF company): 5.7 parts by weight Solvent (propylene glycol 1-monomethyl ether 2-acetate): 412 parts by weight

Prepare a PET film with a thickness of 100 μm as the substrate. The alignment film forming composition was coated on the PET film by a bar coating method, and heated and dried in a drying oven at 90° C. for 1 minute to obtain an alignment film (AL3).

The composition for forming a positive C plate was coated on the alignment film (AL3) by a bar coating method, and heated and dried in a drying oven at 90° C. for 1 minute. Using the above-mentioned UV irradiation device, the resulting film was irradiated with ultraviolet light with a cumulative light amount of 1000 mJ/cm ² (365 nm reference) under a nitrogen atmosphere, thereby forming a positive C plate. The thickness of the resulting positive C plate was 3.0 μm.

(6) Anti-diffusion layer composition (6-1) Composition of anti-diffusion layer 1 The composition of the anti-diffusion layer 1 is 2.8 parts by mass of a dendrimer acrylate having 18 functional acrylic groups (Miramer SP1106, Miwon Corporation), and an acrylic urethane having 6 functional acrylic groups (Miramer PU-620D , Miwon) 6.6 parts by mass, photopolymerization initiator (Irgacure-184, BASF) 0.5 parts by mass, leveling agent (BYK-3530, BYK company) 0.1 parts by mass, and methyl ethyl ketone (MEK) 90 Prepare by mixing parts by mass.

(6-2) Composition of anti-diffusion layer 2 The composition of the anti-diffusion layer 2 is composed of 100 parts by weight of water, 3 parts by weight of polyvinyl alcohol resin powder (manufactured by Kuraray Co., Ltd., average degree of polymerization 18,000, trade name: KL-318), and polyamide epoxy resin (crosslinked The agent, manufactured by Sumika Chemtex Co., Ltd., trade name: SR650 (30)), is prepared by mixing 1.5 parts by weight.

(7) Adhesive layer (Aggregation example 1) Add a mixed solution of 81.8 parts of acetone, 98.4 parts of butyl acrylate, 0.6 parts of acrylic acid, and 1.0 part of 2-hydroxyethyl acrylate to the reactor equipped with a condenser, a nitrogen introduction tube, a thermometer, and a stirrer, while replacing the device with nitrogen The air makes it free of oxygen, while raising the internal temperature to 55°C. Thereafter, a total amount of a solution obtained by dissolving 0.14 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of acetone was added. One hour after the addition of the polymerization initiator, acetone was continuously added to the reactor at an addition rate of 17.3 parts/hour in such a way that the concentration of the acrylic resin other than the monomer became 35%, while the internal temperature was 54-56°C Incubate for 12 hours, then add ethyl acetate to adjust the concentration of acrylic resin to 20%. In this way, an acrylic resin solution was obtained.

(Aggregation example 2) An acrylic resin solution was obtained in the same manner as in Polymerization Example 1, except that the composition of the monomer was changed to 98.6 parts of butyl acrylate, 0.4 parts of acrylic acid, and 1.0 parts of 2-hydroxyethyl acrylate.

(Aggregation example 3) An acrylic resin solution was obtained in the same manner as in Polymerization Example 1, except that the composition of the monomer was changed to 78.0 parts of butyl acrylate, 20 parts of methyl methacrylate, 1.0 parts of acrylic acid, and 1.0 part of 2-hydroxyethyl acrylate.

(Aggregation example 4) An acrylic resin solution was obtained in the same manner as in Polymerization Example 1, except that the composition of the monomer was changed to 68.0 parts of butyl acrylate, 30 parts of methyl methacrylate, 1.0 parts of acrylic acid, and 1.0 part of 2-hydroxyethyl acrylate.

Next, using the acrylic resin solution described above, an adhesive and an adhesive sheet are manufactured. In the following production examples, the following are used as isocyanate-based compounds and silane-based compounds. Isocyanate-based compound: Coronate L, ethyl acetate solution of trimethylolpropane adduct of toluene diisocyanate (solid content concentration 75%), manufactured by Tosoh Co., Ltd. Silane compound: KBM-403, 3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Industry Co., Ltd.

(7-1) Adhesive layer 1 Acrylic resin obtained in mixing polymerization example 1: 100 parts (amount of non-volatile content), Coronate L: 0.5 servings, KBM-403: 0.5 copies. Ethyl acetate was added so that the solid content concentration became 10% to obtain an adhesive composition.

Using an applicator, the resulting adhesive composition was applied to the release treatment surface of the polyethylene terephthalate film (thickness 38 μm) subjected to release treatment so that the thickness after drying became 25 μm. The coating layer was dried at 100° C. for 1 minute to obtain a film with an adhesive layer 1. After that, another polyethylene terephthalate film (thickness 38 μm) that has undergone release treatment is pasted on the adhesive layer. Thereafter, it was aged for 7 days under the conditions of a temperature of 23° C. and a relative humidity of 50% RH.

(7-2) Adhesive layer 2 Acrylic resin obtained by mixing polymerization example 2: 100 parts (amount of non-volatile content), Coronate L: 0.4 copies, KBM-403: 0.5 copies. Ethyl acetate was added so that the solid content concentration became 10% to obtain an adhesive composition. In the same manner as the preparation of the adhesive layer 1, an adhesive layer 2 with a thickness of 25 μm was prepared from the obtained adhesive composition.

(7-3) Adhesive layer 3 Acrylic resin obtained by mixing polymerization example 3: 100 parts (amount of non-volatile content), Coronate L: 3.0 copies, KBM-403: 0.5 copies. Ethyl acetate was added so that the solid content concentration became 10% to obtain an adhesive composition. In the same manner as the preparation of the adhesive layer 1, an adhesive layer 3 with a thickness of 25 μm was prepared from the obtained adhesive composition.

(7-4) Adhesive layer 4 The adhesive layer 4 was produced in the same manner as the production of the adhesive layer 3, except that the thickness after drying became 5 μm.

(7-5) Adhesive layer 5 Acrylic resin obtained by mixing polymerization example 4: 100 parts (amount of non-volatile content), Coronate L: 3.0 copies, KBM-403: 0.5 copies. Ethyl acetate was added so that the solid content concentration became 10% to obtain an adhesive composition. In the same manner as the preparation of the adhesive layer 1, an adhesive layer 5 with a thickness of 25 μm was prepared from the obtained adhesive composition.

(Example 1) A PET film with a thickness of 100 μm was prepared as a base material. The composition of the anti-diffusion layer 1 was coated on the PET film by a bar coating method, and heated and dried in a drying oven at 80° C. for 3 minutes. Using a UV irradiation device (SPOT CURE SP-7, manufactured by Niuwei Electric Co., Ltd.), the obtained film was irradiated with UV light having a dew amount of 500 mJ/cm ² (based on 365 nm) to form an anti-diffusion layer 1. The thickness of the anti-diffusion layer 1 was measured by a laser microscope (OLS3000 manufactured by Olympus Co., Ltd.), and the result was 2.0 μm. In this way, a laminate including the anti-diffusion layer 1/base material (PET) is obtained.

(Preparation of polarizing element) The anti-diffusion layer 1 including the laminate of the anti-diffusion layer 1/base material (PET) was subjected to corona treatment. The conditions for corona treatment are 0.3 kW output and 3 m/min processing speed. Thereafter, the composition for forming the alignment film was coated on the anti-diffusion layer 1 by a bar coating method, and heated and dried in a drying oven at 80° C. for 1 minute. The obtained coating film was subjected to polarized UV irradiation treatment to form an alignment film (AL1). Polarized UV treatment is to pass the light irradiated from the UV irradiation device (SPOT CURE SP-7; manufactured by Niuwei Electric Co., Ltd.) through a wire grid (UIS-27132##, manufactured by Niuwei Electric Co., Ltd.), and measured at a wavelength of 365 nm The cumulative light amount is 100 mJ/cm ² . The thickness of the alignment film (AL1) is 100 nm.

The composition for forming a polarizing element was coated on the formed alignment film (AL1) by a bar coating method, heated and dried in a drying oven at 120° C. for 1 minute, and then cooled to room temperature. Using the above-mentioned UV irradiation device, the coating film was irradiated with ultraviolet rays so that the cumulative light amount became 1200 mJ/cm ² (365 nm reference), thereby forming a polarizing element. The thickness of the obtained polarizing element was 1.8 μm.

The anti-diffusion layer 2 composition was coated on the formed polarizing element by a bar coating method so that the thickness after drying became 1.0 μm, and dried at a temperature of 80° C. for 3 minutes. In this way, a polarizing plate including PET/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2 was obtained.

An adhesive layer 4 is laminated on the anti-diffusion layer 2 of the polarizing plate. Through the adhesive layer 4, a λ/4 retardation plate and a polarizing plate are laminated. Peel the PET film as the base material from the λ/4 retardation plate, and layer the adhesive layer 4 on the exposed area. Through the adhesive layer, a λ/4 retardation plate and a positive C plate are laminated. Peel the PET film as the substrate from the positive C plate.

An adhesive layer 1 is laminated on the front panel 1. The PET film on the anti-diffusion layer 1 is peeled from the polarizing plate, and the polarizing plate and the front panel 1 are laminated via the adhesive layer 1. When bonding each layer, corona treatment is applied to the bonding surface. In this way, an attachment including front panel 1/adhesive layer 1/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive C plate is produced The polarizer on the front panel.

(Example 2) In the same manner as in Example 1, a polarizing plate was produced.

An adhesive layer 1 is laminated on the front panel 1. Via the adhesive layer 1, the anti-diffusion layer 2 and the front panel 1 of the polarizing plate are laminated. Peel the PET film on the anti-diffusion layer 1 and layer the adhesive layer 4 on the exposed area. Through the adhesive layer 4, a λ/4 retardation plate and a polarizing plate are laminated. Peel the PET film as the base material from the λ/4 retardation plate, and layer the adhesive layer 4 on the exposed area. Through the adhesive layer, a λ/4 retardation plate and a positive C plate are laminated. Peel the PET film as the substrate from the positive C plate. In this way, the attachment including the front panel 1/adhesive layer 1/anti-diffusion layer 2/polarizing element/AL1/anti-diffusion layer 1/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive C plate is produced The polarizer on the front panel.

(Example 3) A polarizing plate with a front panel was produced in the same manner as in Example 1, except that the thickness of the anti-diffusion layer 1 was 15 μm. The polarizer with front panel has a front panel 1/adhesive layer 1/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive The composition of the C board.

(Example 4) A polarizing plate with a front panel was produced in the same manner as in Example 1, except that the front panel 1 was changed to the front panel 2. The polarizer with front panel has front panel 2/adhesive layer 1/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive The composition of the C board.

(Example 5) A polarizing plate with a front panel was produced in the same manner as in Example 1 except that the front panel 1 was changed to the front panel 3. The polarizer with front panel has front panel 3/adhesive layer 1/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive The composition of the C board.

(Example 6) A polarizing plate with a front panel was produced in the same manner as in Example 1 except that the adhesive layer 1 was changed to the adhesive layer 2. The polarizer with a front panel has a front panel 1/adhesive layer 2/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive The composition of the C board.

(Example 7) A polarizing plate with a front panel was produced in the same manner as in Example 1 except that the adhesive layer 1 was changed to the adhesive layer 3. The polarizer with front panel has front panel 1/adhesive layer 3/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive The composition of the C board.

(Comparative example 1) A polarizing plate with a front panel was produced in the same manner as in Example 1, except that the anti-diffusion layer 2 was not formed. The polarizing plate with front panel has a configuration of front panel 1/adhesive layer 1/anti-diffusion layer 1/AL1/polarizing element/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive C plate.

(Comparative example 2) A polarizing plate with a front panel was produced in the same manner as in Example 2 except that the anti-diffusion layer 2 was not formed. The polarizing plate with front panel has a composition of front panel 1/adhesive layer 1/polarizing element/AL1/anti-diffusion layer 1/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive C plate.

(Comparative example 3) A polarizing plate with a front panel was produced in the same manner as in Example 1 except that the adhesive layer 1 was changed to the adhesive layer 5. The polarizer with front panel has a front panel 1/adhesive layer 5/anti-diffusion layer 1/AL1/polarizing element/anti-diffusion layer 2/adhesive layer 4/λ/4 retardation plate/adhesive layer 4/positive The composition of the C board.

The above-mentioned evaluation was performed on the polarizing plate with a front panel produced in each example and comparative example. The results are shown in the table below.

[Table 1]

[Table 2]

1: Polarizing element 2: Anti-diffusion layer A 3: Anti-diffusion layer B 4: Front panel 5: retardation film 6: Touch sensor 7: Adhesive layer 10～13: Polarizing plate with front panel 20: polarizer 40: resin film 40a: Main surface 45: Undercoat 45a: Main surface 50: function layer 100: laminate 501: Platform 502: Platform

1(a) and (b) are cross-sectional views showing an example of the configuration of a polarizing plate with a front panel. 2 is a cross-sectional view showing an example of the structure of a polarizing plate with a front panel. 3 is a cross-sectional view showing an example of the structure of a polarizing plate with a front panel. 4 is a cross-sectional view showing an example of the configuration of the front panel. 5 is a cross-sectional view showing an example of the configuration of the front panel. 6 is a cross-sectional view showing an example of the configuration of the front panel. 7(a) and (b) show the method of the bendability test.

1: Polarizing element

2: Anti-diffusion layer A

3: Anti-diffusion layer B

4: Front panel

7: Adhesive layer

10: Polarizer with front panel

11: Polarizer with front panel

20: polarizer

Claims (10)

A polarizing plate with a front panel, comprising: a polarizing plate having an anti-diffusion layer A, a polarizing element, and an anti-diffusion layer B in sequence, and A front panel is arranged on the side opposite to the polarizing element side of the anti-diffusion layer A or the anti-diffusion layer B, and The front panel is laminated on the polarizing plate via an adhesive, The thickness of the anti-diffusion layer A and the anti-diffusion layer B is 20 μm or less, The thickness of the polarizing element is 10 μm or less, The storage modulus of the adhesive forming the above adhesive layer at 25°C is 0.6 MPa or less. The polarizing plate with a front panel according to claim 1, wherein the front panel is provided with a resin film containing a polyimide-based polymer or a polyamide-based polymer, and provided on at least one main surface side of the resin film Laminated film of functional layer. The polarizing plate with a front panel according to claim 2, wherein the above functional layer is a layer having at least one function selected from the group consisting of ultraviolet absorption, surface hardness, hue adjustment, and refractive index adjustment. For the polarizing plate with front panel as claimed in claim 2 or 3, wherein the above-mentioned resin film has a tensile elastic modulus of 4.0 GPa or more, In the bending test in which the operation of bending the resin film into a U shape until the distance between the resin films becomes 3 mm and recovering is repeated, the number of bending times until the resin film is broken More than 100,000 times, The yellowness is 5 or less. The polarizing plate with a front panel according to any one of claims 1 to 4, wherein the polarizing plate is provided with a retardation film on the opposite side of the polarizing element from the front panel side. The polarizing plate with a front panel according to claim 5, wherein the retardation film is laminated on the anti-diffusion layer A or the anti-diffusion layer B via an adhesive layer. The polarizing plate with a front panel as claimed in claim 5 or 6, wherein the retardation film includes a λ/4 retardation plate. The polarizing plate with a front panel according to any one of claims 1 to 7, which has a touch sensor. An organic EL display device provided with a polarizing plate with a front panel according to any one of claims 1 to 8. A flexible image display device including a polarizing plate with a front panel according to any one of claims 1 to 8.

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