JP7133354B2 - Polarizing plate with anti-glare layer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polarizing plate with an anti-glare layer.

Image display devices (for example, liquid crystal display devices, organic EL display devices, and quantum dot display devices) often have a polarizing plate disposed on at least one side of the display cell due to the image forming method thereof. there is The polarizing plate arranged on the viewing side of the image display device is provided with an antireflection layer (antireflection treatment) on the viewing side in order to prevent reflection of external light on the display screen; and/or it is widely known that an anti-glare layer is provided. The anti-glare layer typically includes a resin or adhesive matrix and fine particles dispersed in the matrix. In recent years, along with the demand for thinner image display devices, there is also a strong demand for thinner polarizing plates, and along with this, there is also a demand for thinner anti-reflection layers. As a result, an anti-glare layer, which is an orientation-fixed layer of a liquid crystal compound, has been investigated. However, such a glare-preventing layer has a problem that it is easily peeled off in a high-temperature and high-humidity environment, and wrinkles are likely to occur.

JP 2011-191428 A

The present invention was made to solve the above problems, and its main object is to provide a polarizing plate with an anti-reflection layer in which peeling and wrinkling of the anti-reflection layer are suppressed even in a high-temperature and high-humidity environment. That's what it is.

The anti-glare layer-attached polarizing plate of the present invention comprises a polarizing plate having a polarizer and a protective layer provided on one side of the polarizer, and an alignment and solidification layer of a liquid crystal compound bonded to the protective layer. It comprises an anti-reflection layer, a substrate for the anti-reflection layer, and an adhesive layer provided between the polarizing plate and the anti-reflection layer. In the anti-glare layer-attached polarizing plate of the present invention, the pressure-sensitive adhesive layer has a creep value of 40 μm/h or more.
In one embodiment, an alignment film is further provided between the anti-reflection layer and the substrate for the anti-reflection layer. This alignment film contains a polyvinyl alcohol-based resin.
In one embodiment, the pressure-sensitive adhesive layer has a thickness of 10 μm to 40 μm.
In one embodiment, the antireflection layer-attached polarizing plate of the present invention comprises an antireflection layer and an antireflection layer base material further laminated on the antireflection layer base material.

According to the present invention, in the anti-reflection layer-attached polarizing plate, the pressure-sensitive adhesive layer provided between the polarizing plate and the anti-reflection layer has a creep value of 40 μm/h or more, thereby enabling Also, a polarizing plate with an antireflection layer in which peeling and wrinkling of the antireflection layer are suppressed can be realized.

1 is a schematic cross-sectional view of a polarizing plate with an anti-glare layer according to one embodiment of the present invention; FIG.

Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

A. Overall Configuration of Polarizing Plate with Anti-Reflection Layer FIG. 1 is a schematic cross-sectional view of a polarizing plate with an anti-reflection layer according to one embodiment of the present invention. A polarizing plate 100 with an anti-glare layer includes a polarizing plate 10 having a polarizer 11 and a protective layer 12 provided on one side of the polarizer 11, an anti-glare layer 20, and a substrate 30 for anti-glare layer. and in this order. The protective layer 12 of the polarizing plate 10 and the anti-reflection layer 20 are bonded together with an adhesive layer 40 interposed therebetween. The anti-glare layer 20 is an alignment and solidification layer of a liquid crystal compound. In the anti-glare layer-attached polarizing plate of the present invention, the pressure-sensitive adhesive layer 40 has a creep value of 40 μm/h or more. By bonding the polarizing plate 10 and the anti-reflection layer 20 via such an adhesive layer, it is possible to prevent the anti-reflection layer from peeling off and wrinkling even in a high-temperature, high-humidity environment. As used herein, the term "fixed alignment layer" refers to a layer in which a liquid crystal compound is aligned in a predetermined direction and the alignment state is fixed. In addition, the "alignment fixed layer" is a concept including an alignment cured layer obtained by curing a liquid crystal monomer. The anti-glare layer 20 is typically formed by coating a composition containing a liquid crystal compound on the surface of an alignment film (not shown) formed on the anti-glare layer substrate 30, and solidifying and solidifying the coating layer. / or by curing

In another embodiment of the present invention, the antiglare layer-attached polarizing plate further comprises an antireflection layer and a base material for the antireflection layer (not shown). In this embodiment, the antireflection layer base material is laminated on the side of the antireflection layer base material 30 not in contact with the reflection prevention layer 20, and the antireflection layer can be laminated on the antireflection layer base material. . The antireflection layer can be formed directly on the antireflection layer substrate. As used herein, "directly" means that there is no intervening adhesive layer. In one embodiment, the antireflection layer substrate may have a hard coat layer and/or an adhesion layer (both not shown) on the antireflection layer side surface. This configuration is also included in the form in which "the antireflection layer is directly formed on the substrate." An antifouling layer (not shown) may be further provided on the surface of the antireflection layer, if necessary.

In the illustrated example, the protective layer 12 is provided only on one side of the polarizer 11, but another protective layer may be provided on the side opposite to the protective layer 12 of the polarizer 11 depending on the purpose. In this case, protective layers may be provided on both sides of the polarizer, or the protective layer 12 may be omitted and only another protective layer may be provided. When only another protective layer is provided, the anti-glare layer substrate 30 can function as the viewer-side protective layer. Furthermore, any appropriate functional layer may be provided depending on the purpose. Representative examples of functional layers include a retardation layer and a conductive layer. The type, number, combination, placement position, and properties (for example, refractive index properties, in-plane retardation, thickness direction retardation, and optical properties such as Nz coefficient) of the functional layers can be appropriately set according to the purpose. In one embodiment, a first retardation layer (not shown) having refractive index characteristics of nx>ny>nz may be provided on the opposite side of the polarizer 11 from the protective layer 12 . In this case, preferably, a second retardation layer having refractive index characteristics of nz>nx>ny may be further provided on the opposite side of the first retardation layer from the polarizer. The first retardation layer may also serve as a protective layer on the side opposite to the viewing side of the polarizer. Furthermore, a conductive layer may be provided on the opposite side of the polarizer 11 from the protective layer 12 . By providing the conductive layer at such a position, the polarizing plate with anti-glare layer can be suitably used for an inner touch panel type input display device. In this case, the retardation layer may or may not exist. Each component will be described below.

B. Polarizing Plate The polarizing plate 10 includes a polarizer 11 and a protective layer 12 provided on one surface thereof. The moisture content of the polarizing plate 10 is, for example, 0.5% by weight or more, preferably 0.6% by weight or more, more preferably 0.8% by weight or more, and still more preferably 1.0% by weight. That's it. The moisture content of the polarizing plate is, for example, 2.0% by weight or less. When the polarizing plate has such a high moisture content, the hygroscopic expansion of the polarizing plate can be remarkably suppressed. As a result, dimensional change of the polarizing plate (particularly, dimensional change in the direction of the absorption axis of the polarizer) in a high-temperature and high-humidity environment can be significantly suppressed. When the polarizing plate with anti-glare layer is further provided with an anti-reflection layer, adjusting the moisture content of the anti-reflection layer produces a synergistic effect. Peeling and wrinkling of the anti-immersion layer (orientation-fixing layer of the liquid crystal compound) can be further suppressed. Furthermore, since the polarizing plate has such a high moisture content, even if the polarizing plate with an anti-glare layer according to the embodiment of the present invention curls in a high-temperature and high-humidity environment, the direction of the curl is In the opposite direction to normal. As a result, even if the anti-glare layer-attached polarizing plate according to the embodiment of the present invention curls, the adverse effect on the image display device can be reduced. As described above, due to the synergistic effect of suppressing dimensional change due to the high moisture content of the polarizing plate and the direction of curling, the polarizing plate with the anti-glare layer, when applied to an image display device, It can remarkably suppress warping, peeling, and/or degradation of display characteristics in a high-temperature and high-humidity environment.

B-1. Polarizer The polarizer 11 is typically composed of a resin film containing a dichroic substance.

Any appropriate resin film that can be used as a polarizer can be adopted as the resin film. The resin film is typically a polyvinyl alcohol-based resin (hereinafter referred to as "PVA-based resin") film.

Any appropriate resin may be used as the PVA-based resin forming the PVA-based resin film. Examples thereof include polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. An ethylene-vinyl alcohol copolymer is obtained by saponifying an ethylene-vinyl acetate copolymer. The degree of saponification of the PVA-based resin is usually 85 mol% to 100 mol%, preferably 95.0 mol% to 99.95 mol%, more preferably 99.0 mol% to 99.93 mol%. . The degree of saponification can be determined according to JIS K 6726-1994. By using a PVA-based resin having such a degree of saponification, a polarizer with excellent durability can be obtained. If the degree of saponification is too high, gelation may occur.

The average degree of polymerization of the PVA-based resin can be appropriately selected depending on the purpose. The average degree of polymerization is usually 1,000 to 10,000, preferably 1,200 to 4,500, more preferably 1,500 to 4,300. The average degree of polymerization can be determined according to JIS K 6726-1994.

Dichroic substances contained in the resin film include, for example, iodine and organic dyes. These may be used alone or in combination of two or more. Iodine is preferably used.

The resin film may be a single-layer resin film or a laminate of two or more layers.

A specific example of a polarizer composed of a single-layer resin film is a PVA-based resin film that has been dyed with iodine and stretched (typically, uniaxially stretched). The dyeing with iodine is performed by, for example, immersing the PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial drawing is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment, or may be performed while dyeing. Moreover, you may dye after extending|stretching. If necessary, the PVA-based resin film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, and the like. For example, by immersing the PVA-based resin film in water and washing it with water before dyeing, it is possible not only to wash away stains and anti-blocking agents on the surface of the PVA-based film, but also to swell the PVA-based resin film to prevent uneven dyeing. etc. can be prevented.

Specific examples of the polarizer obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and the resin A polarizer obtained by using a laminate with a PVA-based resin layer formed by coating on a substrate can be mentioned. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer formed by coating on the resin base material is obtained, for example, by applying a PVA-based resin solution to the resin base material and drying the resin base material. forming a PVA-based resin layer thereon to obtain a laminate of a resin substrate and a PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer; obtain. In this embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, stretching may further include stretching the laminate in air at a high temperature (eg, 95° C. or higher) before stretching in an aqueous boric acid solution, if necessary. The obtained resin substrate/polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate/polarizer laminate. Then, any appropriate protective layer may be laminated on the release surface according to the purpose. Details of a method for manufacturing such a polarizer are described, for example, in Japanese Patent Application Laid-Open No. 2012-73580. The publication is incorporated herein by reference in its entirety.

The thickness of the polarizer is preferably 15 μm or less, more preferably 1 μm to 12 μm, even more preferably 3 μm to 10 μm, particularly preferably 3 μm to 8 μm. If the thickness of the polarizer is within such a range, it is possible to satisfactorily suppress curling during heating, and obtain excellent durability in appearance during heating. Furthermore, if the thickness of the polarizer is within such a range, it can contribute to the reduction in thickness of the polarizing plate with the anti-glare layer (as a result, the image display device).

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is preferably 43.0% to 46.0%, more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, still more preferably 99.9% or higher.

B-2. Protective Layer Any appropriate resin film is used as the protective layer 12 . Materials for forming the resin film include, for example, (meth)acrylic resins, cellulose resins such as diacetyl cellulose and triacetyl cellulose, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, and polyethylene terephthalate resins. ester-based resins, polyamide-based resins, polycarbonate-based resins, copolymer resins thereof, and the like. In addition, "(meth)acrylic resin" refers to acrylic resin and/or methacrylic resin.

In one embodiment, a (meth)acrylic resin having a glutarimide structure is used as the (meth)acrylic resin. (Meth)acrylic resins having a glutarimide structure (hereinafter also referred to as glutarimide resins) are disclosed, for example, in JP-A-2006-309033, JP-A-2006-317560, JP-A-2006-328329, JP-A-2006-328329, and JP-A-2006-328329. 2006-328334, JP 2006-337491, JP 2006-337492, JP 2006-337493, JP 2006-337569, JP 2007-009182, JP 2009- No. 161744 and Japanese Patent Application Laid-Open No. 2010-284840. These descriptions are incorporated herein by reference.

The moisture permeability of the protective layer 12 is preferably 1.0 g/m ² /24 hr or less, more preferably 0.8 g/m ² /24 hr or less, and still more preferably 0.6 g/m ² /24 hr or less. and particularly preferably 0.4 g/m ² /24 hr or less. If the moisture permeability of the protective layer is within this range, it is possible to further suppress dimensional changes in a high-temperature and high-humidity environment, and as a result, it is possible to further suppress peeling and wrinkling of the anti-glare layer.

The thickness of the protective layer is typically 10 μm to 100 μm, preferably 20 μm to 40 μm. A protective layer is typically laminated on a polarizer via an adhesive layer (specifically, an adhesive layer, a pressure-sensitive adhesive layer). The adhesive layer is typically formed of a PVA-based adhesive or an activated energy ray-curable adhesive. The adhesive layer is typically formed with an acrylic adhesive. This acrylic pressure-sensitive adhesive may be the same as or different from the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 40 described later.

C. Anti-Reflection Layer The anti-reflection layer is provided to prevent reflection of the user's face of the image display device, the keyboard of the image display device, external light (for example, fluorescent lamp), and the like. In the embodiment of the present invention, the glare-preventing layer 20 is a fixed alignment layer of a liquid crystal compound. As used herein, the term "fixed alignment layer" refers to a layer in which a liquid crystal compound is aligned in a predetermined direction and the alignment state is fixed. In addition, the "alignment fixed layer" is a concept including an alignment cured layer obtained by curing a liquid crystal monomer. The liquid crystal compound may be a rod-like liquid crystal compound, a discotic (disk-like) liquid crystal compound, or a combination thereof.

In one embodiment, the anti-glare layer comprises a discotic liquid crystal compound. More specifically, the anti-glare layer is a layer in which a discotic liquid crystal compound is fixed while oriented in a predetermined direction. Discotic liquid crystal compounds generally have a cyclic mother nucleus such as benzene, 1,3,5-triazine, or calixarene at the center of the molecule, and a linear alkyl group, alkoxy group, or substituted benzoyl A liquid crystal compound having a discotic molecular structure in which oxy groups and the like are radially substituted as side chains. Representative examples of discotic liquid crystals include C.I. Destrade et al., Mol. Cryst. Liq. Cryst. 71, 111 (1981), benzene derivatives, triphenylene derivatives, truxene derivatives and phthalocyanine derivatives; Kohne et al., Angew. Chem. 96, 70 (1984) and cyclohexane derivatives described in J. Am. M. In the report of Lehn et al., J. Am. Chem. Soc. Chem. Commun. , 1794 (1985); In the report of Zhang et al., J. Am. Am. Chem. Soc. 116, 2655 (1994), azacrown-based and phenylacetylene-based macrocycles. Further specific examples of discotic liquid crystal compounds include compounds described in JP-A-2006-133652, JP-A-2007-108732, JP-A-2010-244038, and JP-A-2014-214177. The descriptions in the above documents and publications are incorporated herein by reference. An anti-glare layer containing a discotic liquid crystal compound can typically be a so-called negative A-plate having a refractive index characteristic of nx=nz>ny.

In another embodiment, the anti-glare layer comprises a rod-shaped liquid crystal compound. More specifically, in the anti-glare layer, the rod-like liquid crystal compounds are aligned in a predetermined direction (typically, the slow axis direction) (homogeneous alignment). Examples of rod-like liquid crystal compounds include liquid crystal compounds whose liquid crystal phase is a nematic phase (nematic liquid crystal). As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. Either lyotropic or thermotropic mechanism may be used to develop the liquid crystallinity of the liquid crystal compound. The liquid crystal polymer and liquid crystal monomer may be used alone or in combination. Any suitable liquid crystal monomer can be employed as the liquid crystal monomer. For example, polymerizable mesogenic compounds described in JP-T-2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, and GB2280445 can be used. Specific examples of such polymerizable mesogenic compounds include LC242 (trade name) available from BASF, E7 (trade name) available from Merck, and LC-Sillicon-CC3767 (trade name) available from Wacker-Chem. As the liquid crystal monomer, for example, a nematic liquid crystal monomer is preferable. Specific examples of liquid crystal compounds are described in, for example, JP-A-2006-163343. The description of the publication is incorporated herein by reference. An anti-glare layer containing a rod-shaped liquid crystal compound can typically be a so-called positive A plate having a refractive index characteristic of nx>ny=nz.

The anti-glare layer can typically function as a λ/2 plate. When the anti-reflection layer functions as a λ/2 plate, the reflection can be effectively prevented by controlling the orientation angle (or slow axis direction). The in-plane retardation Re(550) of such an anti-glare layer is 220 nm to 320 nm, preferably 240 nm to 300 nm, still more preferably 250 nm to 280 nm. Here, Re(550) is the in-plane retardation measured with light having a wavelength of 550 nm at 23°C. Re(550) is determined by Re(550)=(nx−ny)×d, where d (nm) is the thickness of the layer (film). nx is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow axis direction), and ny is the refractive index in the in-plane direction perpendicular to the slow axis (that is, the fast axis direction). be.

The angle formed by the slow axis of the anti-glare layer 20 and the absorption axis of the polarizer 11 is preferably 35° to 55°, more preferably 40° to 50°, still more preferably about 45°. be. By arranging the anti-reflection layer functioning as a λ/2 plate at such an axial angle, the reflection can be effectively prevented.

The thickness of the anti-glare layer is preferably 1 μm to 5 μm, more preferably 1 μm to 3 μm. According to the embodiment of the present invention, even such a thin anti-reflection layer can satisfactorily suppress peeling and wrinkling in a high-temperature, high-humidity environment.

When an alignment film is used for aligning the liquid crystal compound, the anti-glare layer-equipped polarizing plate further includes an alignment film between the anti-glare layer 20 and the substrate 30 for anti-glare layer. The alignment film generally contains a polymer material as a main component. Representative examples of polymeric materials include polyvinyl alcohol, polyimide, and derivatives thereof. Modified or unmodified polyvinyl alcohol is preferred in embodiments of the present invention. As the alignment film, for example, modified polyvinyl alcohol described in WO01/88574A1 and Japanese Patent No. 3907735 can be used. The alignment film is typically subjected to an alignment treatment. Typical examples of alignment treatment include rubbing treatment and photo-alignment treatment. Since the rubbing process is well known in the industry, detailed description is omitted. As the photo-aligned alignment film (photo-alignment film), for example, those described in WO2005/096041, trade name LPP-JP265CP manufactured by Rolic technologies, etc. can be used. The thickness of the alignment film is, for example, 0.01 μm to 10 μm, preferably 0.01 μm to 1 μm, more preferably 0.01 μm to 0.5 μm.

The anti-glare layer can be formed, for example, by the following procedure. First, a coating solution for forming an alignment film is applied onto a substrate for anti-glare layer and dried to form a coating film. The coating film is rubbed in a predetermined direction to form an alignment film on the anti-glare layer base material. The predetermined direction can correspond to the slow axis direction of the resulting anti-glare layer. Next, a coating solution for forming an anti-glare layer (for example, a solution containing a liquid crystal compound and optionally a cross-linkable monomer) is applied onto the formed alignment film and heated. Heating removes the solvent of the coating liquid and advances the orientation of the liquid crystal compound. Heating may be carried out in one step, or may be carried out in multiple steps by changing the temperature. Next, the crosslinkable (or polymerizable) monomer is crosslinked (or polymerized) by UV irradiation to fix the orientation of the liquid crystal compound. In this way, the anti-reflection layer is formed on the anti-reflection layer substrate (substantially, on the alignment film). A method for orienting a discotic liquid crystal compound is described, for example, in JP-A-2014-214177, and a method for orienting a rod-like liquid crystal compound is described, for example, in JP-A-2006-163343. The descriptions of these publications are incorporated herein by reference. The alignment film may be omitted depending on the desired alignment state, the type of liquid crystal compound, and the like.

D. Anti-Reflection Layer Substrate The anti-reflection layer substrate 30 is used to form the anti-reflection layer 20 . Any appropriate resin film is used as the substrate for the anti-glare layer. Examples of resin film-forming materials include polyester resins such as polyethylene terephthalate (PET), cycloolefin resins such as norbornene resins, addition of cycloolefins (e.g., norbornene) and α-olefins (e.g., ethylene). Resins obtained by polymerization (COC), cellulosic resins such as triacetyl cellulose (TAC), acrylic resins, and the like can be mentioned.

The thickness of the anti-glare layer substrate can be appropriately set according to the purpose. The thickness of the anti-glare layer substrate is typically 20 μm to 200 μm, preferably 25 μm to 100 μm.

E. Adhesive Layer The adhesive layer 40 is provided between the polarizing plate 10 and the anti-glare layer 20 . In the illustrated example, the polarizing plate 10 and the anti-reflection layer 20 are laminated with the protective layer 12 and the anti-reflection layer 20 via the adhesive layer 40. When only another protective layer is provided, the polarizer 10 and the anti-reflection layer 20 may be laminated via the adhesive layer 40 .

In the anti-glare layer-attached polarizing plate of the present invention, the pressure-sensitive adhesive layer 40 has a creep value of 40 μm/h or more. By bonding the polarizing plate 10 and the anti-reflection layer 20 via such an adhesive layer, it is possible to prevent the anti-reflection layer from peeling off and wrinkling even in a high-temperature, high-humidity environment. The creep value of the adhesive layer 40 is preferably 50 μm/h or more, more preferably 60 μm/h or more. When the creep value of the pressure-sensitive adhesive layer is less than 40 μm/h, it may not be possible to sufficiently suppress the peeling of the anti-glare layer and the generation of wrinkles. Moreover, the creep value of the pressure-sensitive adhesive layer is, for example, 200 μm/h or less.

The creep value of the pressure-sensitive adhesive layer can be measured as follows. A pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive composition to a protective layer of a polarizing plate including a protective layer and a polarizer to prepare a pressure-sensitive adhesive layer-attached polarizing plate. The prepared polarizing plate is cut into 10 mm width×50 mm length. Of the cut polarizing plate with an adhesive layer, a portion of width 10 mm × length 10 mm was attached to a stainless steel plate via the adhesive layer, and then treated in an autoclave (50 ° C., 5 atm) for 15 minutes. Leave at room temperature for 1 hour. After standing, a load of 500 g (tensile load) was applied at 23 ° C. for 1 hour to the end of the adhesive layer-attached polarizing plate that was not attached to the stainless steel plate, and the adhesive after applying the load. The creep value of the pressure-sensitive adhesive layer can be measured by measuring the displacement amount (deformation amount) of the layer using a laser creep tester.

The creep value of the adhesive layer can be adjusted by any suitable method. For example, it can be adjusted by adjusting the molecular weight of the base polymer in the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer, the addition amount of the cross-linking agent in the pressure-sensitive adhesive, and the like. More specifically, the creep value of the pressure-sensitive adhesive layer can be reduced by using a polymer with a high molecular weight as the base polymer and/or increasing the amount of the cross-linking agent added. In addition, the creep value of the pressure-sensitive adhesive layer can be increased by using a polymer with a low molecular weight as the base polymer and/or by reducing the amount of the cross-linking agent added.

The thickness of the adhesive layer is preferably 1 μm to 50 μm, more preferably 10 μm to 40 μm.

Any appropriate adhesive can be used as the adhesive that forms the adhesive layer. Examples of adhesives include acrylic adhesives, acrylic urethane adhesives, urethane adhesives, silicone adhesives, organic-inorganic hybrid adhesives, and the like. Acrylic pressure-sensitive adhesives are preferable from the viewpoint of transparency and durability.

The acrylic pressure-sensitive adhesive is, for example, an acrylic polymer using one or more of (meth)acrylic acid alkyl esters as a monomer component, that is, a polymer having structural units derived from (meth)acrylic acid alkyl esters. (homopolymer or copolymer) as a base polymer. Specific examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) ) isobutyl acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate , 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, (meth)acrylic acid Undecyl, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate , C1-C20 alkyl (meth)acrylates such as nonadecyl (meth)acrylate and eicosyl (meth)acrylate. Among them, (meth)acrylic acid alkyl esters having a linear or branched alkyl group with 4 to 18 carbon atoms are preferably used. The content of structural units derived from (meth)acrylic acid alkyl ester is preferably 60 parts by weight or more, more preferably 80 parts by weight or more, relative to 100 parts by weight of the base polymer.

For the purpose of modifying cohesive strength, heat resistance, crosslinkability, etc., the acrylic polymer may be composed of other monomer components copolymerizable with the (meth)acrylic acid alkyl ester, if necessary. May contain units. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; maleic anhydride and icotanic anhydride; Acid anhydride monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalene Examples thereof include sulfonic acid group-containing monomers such as sulfonic acid.

In one embodiment, a hydroxyl group-containing monomer is used as the monomer component. Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, ( 8-Hydroxyoctyl meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)-methyl acrylate and the like can be mentioned. When an isocyanate-based cross-linking agent is used as the cross-linking agent, 4-hydroxybutyl acrylate is preferred among these from the viewpoint of efficiently securing a cross-linking point with an isocyanate group. The content of structural units derived from a hydroxyl group-containing monomer is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 2 parts by weight, relative to 100 parts by weight of the base polymer. .

Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, peroxide-based cross-linking agents, melamine-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, metal chelate-based cross-linking agents, and metal salt-based cross-linking agents. cross-linking agent, carbodiimide-based cross-linking agent, oxazoline-based cross-linking agent, aziridine-based cross-linking agent, amine-based cross-linking agent, and the like. Among them, isocyanate-based cross-linking agents, epoxy-based cross-linking agents and/or peroxide-based cross-linking agents are preferably used. The cross-linking agents may be used alone or in combination of two or more.

Any appropriate cross-linking agent can be used as the isocyanate-based cross-linking agent. Examples of isocyanate-based cross-linking agents include isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and hydrogenated diphenylmethane diisocyanate; and isocyanate compounds obtained by adding polyols such as.

Any appropriate cross-linking agent can be used as the epoxy-based cross-linking agent. As the epoxy-based cross-linking agent, for example, an epoxy-based resin having two or more epoxy groups in the molecule is used. Specifically, diglycidylaniline and 1,3-bis(N,N-glycidylaminomethyl)cyclohexane are used. , N,N,N',N'-tetraglycidyl-m-xylenediamine, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and the like. be done.

Any appropriate cross-linking agent can be used as the peroxide-based cross-linking agent. Examples of peroxide-based cross-linking agents include dibenzoyl peroxide, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, and di-sec-butylperoxydicarbonate. , t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate and the like.

The amount of the cross-linking agent added is preferably 0.01 to 5 parts by weight, more preferably 0.02 to 3 parts by weight, and still more preferably 0 parts by weight with respect to 100 parts by weight of the base polymer. .1 to 2.5 parts by weight, particularly preferably 0.4 to 1 part by weight. Within such a range, a pressure-sensitive adhesive layer having an appropriate creep value can be formed.

In one embodiment, the adhesive forming the adhesive layer may further contain a silane coupling agent. Silane coupling agents include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl). Epoxy group-containing silane coupling agents such as ethyltrimethoxysilane; 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1, 3-dimethylbutylidene)propylamine, amino group-containing silane coupling agents such as N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents; isocyanate group-containing silane coupling agents; mentioned.

The amount of the silane coupling agent added is preferably 0.01 to 1 part by weight, more preferably 0.05 to 0.5 part by weight, per 100 parts by weight of the base polymer.

The pressure-sensitive adhesive may further contain any appropriate additive as necessary. The additives include, for example, tackifiers, plasticizers, pigments, dyes, fillers, antioxidants, conductive materials, ultraviolet absorbers, light stabilizers, release modifiers, softeners, surfactants, flame retardants. etc.

F. Base material for antireflection layer F-1. Antireflection Layer Substrate Body The antireflection layer substrate is used to form the antireflection layer. As will be described later, an antireflection layer is formed on a base material for an antireflection layer, and a laminate of the base material for an antireflection layer/antireflection layer is adhered to a polarizing plate, whereby the polarizing plate is subjected to an antireflection layer forming process ( Typically, the need for sputtering) is eliminated.

The forming material and thickness of the base material for the antireflection layer are the same as those for the antireflection layer base material.

In one embodiment, the moisture content of the antireflection layer substrate is, for example, 2.0% by weight or more, preferably 2.4% by weight or more, and more preferably 2.7% by weight or more. more preferably 3.0% by weight or more, and particularly preferably 3.5% by weight or more. The moisture content of the antireflection layer substrate is, for example, 5.0% by weight or less. When the base material for an antireflection layer has such a high moisture content, peeling and wrinkling of the anti-glare layer (orientation and solidification layer of the liquid crystal compound) in a high-temperature and high-humidity environment can be suppressed. In the present specification, the term "moisture content of the antireflection layer base material" refers to the moisture content of the antireflection layer base material when the antireflection laminate is laminated in the manufacturing method described later in Section J.

F-2. Hard Coat Layer A hard coat layer may be formed on the antireflection layer side surface of the antireflection layer substrate. By forming a hard coat layer, there is an advantage of improving the pencil hardness. Furthermore, the reflectance can be further reduced by appropriately adjusting the refractive index difference between the hard coat layer and the antireflection layer.

The hard coat layer preferably has sufficient surface hardness, excellent mechanical strength, and excellent optical transparency. The hard coat layer can be formed from any suitable resin as long as it has such desired properties. Specific examples of resins include thermosetting resins, thermoplastic resins, ultraviolet curing resins, electron beam curing resins, and two-liquid mixed resins. A UV curable resin is preferred. This is because the hard coat layer can be formed with simple operation and high efficiency.

Specific examples of UV curable resins include polyester, acrylic, urethane, amide, silicone and epoxy UV curable resins. UV-curable resins include UV-curable monomers, oligomers, and polymers. Preferred UV-curable resins include resin compositions containing acrylic monomer or oligomer components having preferably 2 or more, more preferably 3 to 6, UV-polymerizable functional groups. Typically, the UV curable resin contains a photopolymerization initiator.

A hard coat layer may be formed by any appropriate method. For example, the hard coat layer can be formed by coating a resin composition for forming a hard coat layer on a base material for an antireflection layer, drying it, and curing the dried coating film by irradiating it with ultraviolet rays.

The thickness of the hard coat layer is, for example, 0.5 μm to 20 μm, preferably 1 μm to 15 μm.

Details of the hard coat layer and the adhesion structure between the hard coat layer and the antireflection layer are described in, for example, JP-A-2016-224443. The description of the publication is incorporated herein by reference.

G. Antireflection Layer Any appropriate configuration can be adopted as the configuration of the antireflection layer. A typical structure of the antireflection layer includes (1) a single layer of a low refractive index layer having an optical thickness of 120 nm to 140 nm and a refractive index of about 1.35 to 1.55; Laminates having medium refractive index layers, high refractive index layers and low refractive index layers in order from the substrate side; (3) alternating multilayer laminates of high refractive index layers and low refractive index layers;

Materials that can form the low refractive index layer include, for example, silicon oxide (SiO ₂ ) and magnesium fluoride (MgF ₂ ). The refractive index of the low refractive index layer is typically about 1.35 to 1.55. Materials capable of forming the high refractive index layer include, for example, titanium oxide (TiO ₂ ), niobium oxide (Nb ₂ O ₃ or Nb ₂ O ₅ ), tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), ZrO ₂ —TiO ₂ can be mentioned. The refractive index of the high refractive index layer is typically about 1.60 to 2.20. Materials capable of forming the medium refractive index layer include, for example, titanium oxide (TiO ₂ ), a mixture of a material capable of forming a low refractive index layer and a material capable of forming a high refractive index layer (for example, titanium oxide and oxide mixtures with silicon). The refractive index of the medium refractive index layer is typically about 1.50 to 1.85. The thicknesses of the low refractive index layer, the medium refractive index layer, and the high refractive index layer can be set so as to realize an appropriate optical film thickness according to the layer structure of the antireflection layer, desired antireflection performance, and the like.

An antireflection layer is typically formed by a dry process. Specific examples of the dry process include a PVD (Physical Vapor Deposition) method and a CVD (Chemical Vapor Deposition) method. PVD methods include a vacuum deposition method, a reactive deposition method, an ion beam assist method, a sputtering method, and an ion plating method. As the CVD method, there is a plasma CVD method. Sputtering is preferred.

The thickness of the antireflection layer is, for example, about 20 nm to 300 nm.

In the antireflection layer, the difference between the maximum reflectance and the minimum reflectance in the wavelength range of 400 nm to 700 nm is preferably 2.0% or less, more preferably 1.9% or less, and still more preferably 1.8%. % or less. If the difference between the maximum reflectance and the minimum reflectance is in such a range, it is possible to satisfactorily prevent the coloring of the reflected light.

If necessary, an antifouling layer may be provided on the surface of the antireflection layer. The antifouling layer contains, for example, a fluorine group-containing silane compound (for example, an alkoxysilane compound having a perfluoropolyether group) or a fluorine group-containing organic compound. The antifouling layer preferably exhibits water repellency with a water contact angle of 110 degrees or more.

H. First Retardation Layer The first retardation layer may be composed of a retardation film having any appropriate optical properties and/or mechanical properties depending on the purpose. In one embodiment, the first retardation layer can function as a λ/2 plate. By the first retardation layer functioning as a λ / 2 plate, the wavelength dispersion characteristics after lamination with the second retardation layer functioning as a λ / 4 plate (in particular, the wavelength where the phase difference is outside λ / 4 range), the phase difference can be adjusted appropriately. The in-plane retardation Re(550) of such a first retardation layer is preferably 220 nm to 320 nm, more preferably 240 nm to 300 nm, still more preferably 250 nm to 280 nm.

The thickness of the first retardation layer can be set so as to function most appropriately as a λ/2 plate. In other words, the thickness can be set to obtain the desired in-plane retardation. Specifically, the thickness is preferably 10 μm to 60 μm, more preferably 30 μm to 50 μm.

The first retardation layer preferably exhibits a refractive index characteristic of nx>ny>nz. The Nz coefficient of the first retardation layer is preferably 1.1-3.0, more preferably 1.3-2.7. The Nz coefficient is obtained by Nz=Rth/Re. Rth is the retardation in the thickness direction. For example, Rth(550) is the retardation in the thickness direction measured at 23° C. with light having a wavelength of 550 nm. Rth(550) is obtained by Rth=(nx−nz)×d. nz is the refractive index in the thickness direction.

The first retardation layer is arranged such that its slow axis forms an angle of preferably 10° to 20°, more preferably 12° to 18°, and more preferably about 15° with the absorption axis of the polarizer. can be It should be noted that references herein to angles include both clockwise and counterclockwise.

The absolute value of the photoelastic coefficient of the first retardation layer is preferably 2×10 ⁻¹¹ m ² /N or less, more preferably 2.0×10 ⁻¹³ m ² /N to 1.5×10 ⁻¹¹ m ² /N, more preferably 1.0×10 ⁻¹² m ² /N to 1.2×10 ⁻¹¹ m ² /N of resin. If the absolute value of the photoelastic coefficient is within such a range, the phase difference is less likely to change when shrinkage stress occurs during heating. Therefore, by forming the first retardation layer using a resin having such an absolute value of the photoelastic coefficient, when the polarizing plate with the anti-glare layer is applied to an image display device, the heat unevenness is improved. can be prevented.

The first retardation layer may exhibit a reverse wavelength dispersion characteristic in which the retardation value increases according to the wavelength of the measurement light, or has a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light. It may also show a flat wavelength dispersion characteristic in which the phase difference value hardly changes even with the wavelength of the measurement light. It preferably exhibits a flat wavelength dispersion characteristic. Specifically, Re(450)/Re(550) of the first retardation layer is preferably 0.99 to 1.03, and Re(650)/Re(550) is preferably 0.98 to 1.02. By arranging a λ / 2 plate (first retardation layer) and a λ / 4 plate (second retardation layer) having flat wavelength dispersion characteristics at a predetermined axis angle, ideal reverse wavelength dispersion It is possible to obtain characteristics close to the characteristics, and as a result, very excellent antireflection characteristics can be realized.

The first retardation layer may be composed of any appropriate resin film that can satisfy the properties as described above. Representative examples of such resins include cyclic olefin-based resins, polycarbonate-based resins, cellulose-based resins, polyester-based resins, polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polystyrene-based resins, and acrylic resins. system resin. Among them, cyclic olefin resins can be preferably used. The first retardation layer is obtained, for example, by stretching a film formed from the above resin. Details of the cyclic olefin resin and the stretching method of the resin film (method of forming the retardation film) are described in, for example, JP-A-2015-210459 and JP-A-2016-105166. The description of this publication is incorporated herein by reference.

I. Second Retardation Layer The second retardation layer may be composed of a retardation film having any appropriate optical properties and/or mechanical properties depending on the purpose. When the first retardation layer functions as a λ/2 plate, the second retardation layer can typically function as a λ/4 plate. By correcting the wavelength dispersion characteristics of the second retardation layer that functions as a λ / 4 plate by the optical characteristics of the first retardation layer that functions as the λ / 2 plate, a circularly polarized light function in a wide wavelength range can be demonstrated. The in-plane retardation Re(550) of such a second retardation layer is preferably 100 nm to 180 nm, more preferably 110 nm to 170 nm, still more preferably 120 nm to 160 nm.

The thickness of the second retardation layer can be set so as to function most appropriately as a λ/4 plate. In other words, the thickness can be set to obtain the desired in-plane retardation. Specifically, the thickness is preferably 10 μm to 50 μm, more preferably 20 μm to 40 μm.

The second retardation layer preferably exhibits a refractive index characteristic of nz>nx>ny. The Nz coefficient of the second retardation layer is preferably -10 to -0.1, more preferably -5 to -1.

The second retardation layer is arranged such that its slow axis forms an angle of preferably 70° to 80°, more preferably 72° to 78°, more preferably about 75° with the absorption axis of the polarizer. can be

The second retardation layer may be composed of any appropriate resin film that can satisfy the properties as described above. Such resins can typically be polymers with negative intrinsic birefringence. A polymer having negative intrinsic birefringence refers to a polymer whose refractive index in the orientation direction is relatively small when the polymer is oriented by stretching or the like. Examples of polymers having negative intrinsic birefringence include those in which chemical bonds or functional groups with large polarization anisotropy such as aromatic groups and carbonyl groups are introduced into the side chains of the polymer. Specific examples include modified polyolefin-based resins (eg, modified polyethylene-based resins), acrylic resins, styrene-based resins, maleimide-based resins, fumarate-based resins, and the like. The second retardation layer can be obtained, for example, by appropriately stretching a film formed from the above resin.

J. Method for producing a polarizing plate with an anti-glare layer A method for producing a polarizing plate with an anti-glare layer according to one embodiment of the present invention comprises producing a polarizer laminate (polarizing plate) including a polarizer and a protective layer, The method includes forming an anti-reflection layer on a substrate for an anti-reflection layer to prepare an anti-reflection laminate, and bonding the polarizer laminate and the anti-reflection laminate together. When the antireflection layer-attached polarizing plate further includes an antireflection layer and an antireflection layer base material, the method for producing the reflection prevention layer-attached polarizing plate includes forming the antireflection layer on the antireflection layer base material, The method further includes the steps of forming an antireflection laminate, and bonding the polarizer laminate and the antireflection laminate to the antireflection laminate.

A polarizer laminate can be made by any suitable method. When a polarizer composed of a single-layer resin film is used, the polarizer and the resin film that constitutes the protective layer may be laminated via any suitable adhesive layer (adhesive layer or adhesive layer). good. When using a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, the laminate is dyed and stretched to convert the PVA-based resin layer into a polarizer. , and this laminate may be used as it is as a polarizer laminate. Alternatively, a resin film constituting a protective layer may be adhered to the surface of the polarizer of this laminate. In this case, the resin substrate may or may not be peeled off. When using a polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate, as described in the above section B-1 (for example, 2012-73580), and this laminate may be used as it is as the polarizer laminate. Alternatively, a resin film constituting a protective layer may be adhered to the surface of the polarizer of this laminate. In this case, the resin substrate may or may not be peeled off.

The anti-reflection laminate is produced by forming an anti-reflection layer on a substrate for an anti-reflection layer. The procedure for forming the anti-glare layer is as described in section C above.

The antireflection laminate is produced by forming an antireflection layer on a substrate for an antireflection layer. When forming the antireflection layer, if necessary, the base material for the antireflection layer may be surface-treated in advance. Surface treatments include, for example, low-pressure plasma treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment. Alternatively, an adhesion layer made of, for example, SiOx may be formed on the surface of the antireflection layer substrate. The antireflection layer is typically formed by a dry process (eg, sputtering), as described above. For example, when the antireflection layer is an alternating multilayer laminate of high refractive index layers and low refractive index layers, for example, Nb ₂ O ₅ film (high refractive index layer), SiO ₂ An antireflection layer can be formed by sequentially depositing a film (low refractive index layer), a Nb ₂ O ₅ film (high refractive index layer), and a SiO ₂ film (low refractive index layer).

Finally, a polarizing plate with an anti-glare layer can be obtained by laminating a polarizer laminate, an anti-glare laminate, and, if necessary, an anti-reflection laminate. When the anti-glare layer-attached polarizing plate further includes an anti-reflection layer and a base material for an anti-reflection layer, the anti-reflection laminate may be laminated to the anti-glare laminate/polarizer laminate. A laminate of anti-glare laminate/anti-glare laminate may be attached to the polarizer laminate. The anti-reflection layer-attached polarizing plate can be obtained, for example, by bonding the anti-reflection layer of the anti-reflection laminate to the surface of the protective layer of the polarizer laminate via the pressure-sensitive adhesive layer. In the case where the polarizing plate with an anti-glare layer further comprises an anti-reflection layer, after the polarizer laminate and the anti-glare layer laminate are bonded together, an optional can be obtained by laminating the substrate for the antireflection layer of the antireflection laminate via an appropriate adhesive layer (for example, an adhesive layer, a pressure-sensitive adhesive layer) of the antireflection laminate.

K. Image Display Device The polarizing plate with anti-glare layer according to the embodiment of the present invention can be applied to an image display device. Typically, it can be arranged on the viewing side of the image display device so that the anti-glare layer is on the viewing side. When the polarizing plate with an antireflection layer further includes an antireflection layer, the polarizing plate with an antireflection layer can be arranged on the viewer side of the image display device so that the antireflection layer is on the viewer side. Typical examples of image display devices include liquid crystal display devices, organic electroluminescence (EL) display devices, and quantum dot display devices.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. In addition, the measuring method of each characteristic is as follows.

(1) Creep value of adhesive layer The edge of the measurement sample (width 10 mm x length 10 mm) cut into 10 mm width x 50 mm length was attached to a stainless steel plate via the adhesive layer. After autoclave treatment at atmospheric pressure for 15 minutes, leave at room temperature for 1 hour, then load 500 g (tensile load) at 23 ° C. for 1 hour on the end opposite to the end attached to the stainless steel plate. The displacement (deformation amount) of the pressure-sensitive adhesive layer was measured at this time, and this was taken as the creep value of the pressure-sensitive adhesive layer (laser type creep tester).

(2) Peeling and wrinkles The polarizing plates with anti-reflection layers obtained in Examples and Comparative Examples were cut into pieces of 300 mm × 180 mm so that the absorption axis direction of the polarizer is the short side, and the measurement was performed by attaching them to a glass plate. It was used as a sample. This measurement sample was placed under humidified conditions (an oven at 65° C. and 90% RH) for 72 hours, and the presence or absence of peeling and wrinkling at the four corners of each sample was visually confirmed. When peeling and wrinkling occurred, the distance (R) from the apex of each corner to the peeling and wrinkling was measured with a ruler. The average value of the distances (R) measured at the four corners was taken as the distance (R) of the polarizing plate. When the distance (R) is 5 mm or less, it can withstand practical use.

<Synthesis Example 1> Synthesis of Adhesive 1 100 parts of butyl acrylate, 5 parts of acrylic acid, and 0.075 parts of 2-hydroxyethyl acrylate were added to a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirring device. and 0.3 parts of 2,2'-azobisisobutyronitrile were added together with ethyl acetate to prepare a solution. Next, this solution was stirred while blowing nitrogen gas, and reacted at 60° C. for 4 hours to obtain a solution containing an acrylic polymer having a weight-average molecular weight of 2,200,000. Further, an acrylic polymer solution (A1) was obtained by adding ethyl acetate to the solution containing the acrylic polymer to adjust the solid content concentration to 30%.
Per 100 parts of the solid content of the obtained acrylic polymer solution (A1), 0.6 parts of a crosslinking agent mainly composed of a compound having an isocyanate group (manufactured by Nippon Polyurethane Co., Ltd., trade name "Coronate L") and 0.075 parts of γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KMB-403") as a silane coupling agent were blended in this order. Thus, an adhesive 1 was prepared.

<Synthesis Example 2> Synthesis of Adhesive 2 99 parts of butyl acrylate, 1.0 part of 4-hydroxybutyl acrylate and 2,2' were added to a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirring device. -Azobisisobutyronitrile (0.3 part) was added together with ethyl acetate and reacted at 60°C for 4 hours under a nitrogen gas stream. Next, ethyl acetate was added to the reaction solution to obtain a solution (solid concentration: 30%) containing an acrylic polymer with a weight average molecular weight of 1,650,000.
0.15 parts of dibenzoyl peroxide (manufactured by NOF Corporation, trade name: Nyper BO-Y) per 100 parts of the solid content of the obtained acrylic polymer solution, 0.08 parts of trimethylolpropane xylene diisocyanate (manufactured by Mitsui Takeda Chemicals Co., Ltd., trade name: Takenate D110N) and 0.2 parts of a silane coupling agent (manufactured by Soken Chemical Co., Ltd., trade name: A-100, an acetoacetyl group-containing silane coupling agent) to acrylic Adhesive 2 was prepared by adding to the system polymer solution.

<Synthesis Example 3> Synthesis of Adhesive 3 0.15 parts of dibenzoyl peroxide (manufactured by NOF Corporation, trade name: Nyper BO-Y) per 100 parts of the solid content of the acrylic polymer solution, 0.02 parts of trimethylolpropane xylene diisocyanate (manufactured by Mitsui Takeda Chemicals Co., Ltd., trade name: Takenate D110N) and 0.2 parts of a silane coupling agent (manufactured by Soken Chemical Co., Ltd., trade name: A-100, an acetoacetyl group-containing silane Coupling agent) was added to the acrylic polymer solution in the same manner as in Synthesis Example 2 to prepare Adhesive 3.

<Synthesis Example 4> Synthesis of Adhesive Composition 4 Into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirring device, 81.9 parts of butyl acrylate, 13 parts of benzyl acrylate, 5 parts of acrylic acid, 4- 0.1 part of hydroxybutyl acrylate and 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator were charged together with 100 parts of ethyl acetate, and nitrogen gas was introduced while gently stirring to replace nitrogen gas. Subsequently, the liquid temperature in the flask was maintained at around 55° C., and the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution.
Based on 100 parts of the solid content of the obtained acrylic polymer solution, 0.45 parts of an isocyanate cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L, an adduct of tolylene diisocyanate of trimethylolpropane), 0 .1 part of benzoyl peroxide (manufactured by NOF Corporation, trade name: Nyper BMT) and 0.1 part of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM403) are added to an acrylic polymer. Adhesive 4 was prepared by adding to the solution.

[Example 1]
1. Preparation of polarizing plate (polarizer laminate) As a resin substrate, a long, amorphous isophthalic acid-copolymerized polyethylene terephthalate (IPA-copolymerized PET) film with a Tg of 75°C and a water absorption of 0.75% (thickness: 100 μm) was used. One side of the substrate was subjected to corona treatment, and the corona-treated side was coated with polyvinyl alcohol (degree of polymerization: 4,200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (degree of polymerization: 1,200, degree of acetoacetyl modification: 4.6). %, degree of saponification 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOSEFIMER Z200") at a ratio of 9:1. A PVA-based resin layer was formed to produce a laminate.
The resulting laminate was uniaxially stretched 2.0 times at the free end in the machine direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 120° C. (in-air auxiliary stretching).
Next, the laminate was immersed in an insolubilizing bath (an aqueous boric acid solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 30° C. for 30 seconds (insolubilizing treatment).
Then, it was immersed in a dyeing bath at a liquid temperature of 30° C. while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance. In this example, 0.2 parts by weight of iodine was added to 100 parts by weight of water, and 1.5 parts by weight of potassium iodide was added to the resulting iodine aqueous solution for 60 seconds (dyeing treatment). .
Next, it was immersed for 30 seconds in a cross-linking bath at a liquid temperature of 30°C (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water). (crosslinking treatment).
After that, the laminate is immersed in an aqueous solution of boric acid having a liquid temperature of 70° C. (an aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water). Meanwhile, the film was uniaxially stretched in the machine direction (longitudinal direction) between rolls with different circumferential speeds so that the total draw ratio was 5.5 (underwater stretching).
After that, the laminate was immersed in a cleaning bath having a liquid temperature of 30° C. (aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
Subsequently, on the surface of the PVA-based resin layer (polarizer) of the laminate, a PVA-based resin aqueous solution (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOSEFIMER (registered trademark) Z-200", resin concentration: 3% by weight ) was applied, a methacrylic resin film (thickness: 25 μm, having a glutarimide structure) constituting a protective layer was adhered, and this was heated in an oven maintained at 60° C. for 5 minutes. After that, the resin substrate was peeled off from the PVA-based resin layer. Subsequently, a PVA-based resin aqueous solution (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOSEFIMER (registered trademark) Z-200", resin concentration: 3% by weight) was applied, and a methacrylic resin film (thickness: 40 μm, having a glutarimide structure) constituting the protective layer was adhered and heated in an oven maintained at 60° C. for 5 minutes. Thus, a polarizer laminate (a polarizing plate having a structure of protective layer/polarizer/protective layer) was obtained. The polarizer had a thickness of 5 μm and a single transmittance of 42.3%.

2. Anti-reflection laminate On one side of a TAC film (product name: KC4UY, thickness: 40 μm) manufactured by Konica Minolta Co., Ltd. as a base material for the anti-reflection layer, a layer of <Example 1> of Japanese Patent Application Laid-Open No. 2014-214177 is applied. An alignment film and an oriented fixed layer of a liquid crystal compound (anti-glare layer) were formed according to the method described above to prepare an anti-glare laminate. The anti-glare layer had an in-plane retardation Re(550) of 270 nm, and was formed so that its slow axis formed an angle of 45° with respect to the absorption axis of the polarizer.

3. Preparation of antireflection laminate HC- (HC- A TAC film (thickness: 32 μm) was obtained. This HC-TAC film was used as a substrate for an antireflection layer. An adhesion layer made of SiOx (thickness: 10 nm) was formed by sputtering on the surface of the HC layer of the substrate for the antireflection layer, and a Nb ₂ O ₅ film (high refractive index layer) and an SiO ₂ film were formed on the adhesion layer. (low refractive index layer), Nb ₂ O ₅ film (high refractive index layer), and SiO ₂ film (low refractive index layer) are sequentially formed to form an antireflection layer (thickness or optical film thickness: 200 nm). formed. Furthermore, an antifouling layer (thickness: 10 nm) made of an alkoxysilane compound having a perfluoropolyether group was formed on the antireflection layer to prepare an antireflection laminate.

4. Preparation of polarizing plate with anti-reflection layer On the 40 μm protective layer surface of the polarizer laminate (polarizing plate), the adhesive 1 obtained in Synthesis Example 1 was applied so that the thickness after drying was 20 μm, and the anti-reflection lamination was performed. A body reflection prevention layer was pasted together. Adhesive 1 was applied to the surface of the anti-reflection layer base material of the obtained laminate so that the thickness after drying was 20 μm, and the HC-TAC film of the anti-reflection laminate was laminated to obtain an anti-reflection layer. A polarizing plate with an anti-glare layer further containing The obtained anti-glare layer-attached polarizing plate was subjected to the above evaluations (1) and (2). Table 1 shows the results.

[Example 2]
A polarizing plate with an anti-glare layer was produced in the same manner as in Example 1, except that the adhesive 2 obtained in Synthesis Example 2 was used to bond the anti-glare layer laminate and the polarizer laminate together. The obtained polarizing plate was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 3]
A polarizing plate with an anti-glare layer was produced in the same manner as in Example 1, except that the adhesive 3 obtained in Synthesis Example 3 was used to bond the anti-glare layer laminate and the polarizer laminate together. The obtained polarizing plate was subjected to the same evaluation as in Example 1. Table 1 shows the results.

[Example 4]
A polarizing plate with an anti-reflection layer was produced in the same manner as in Example 1, except that an acrylic resin film (thickness: 40 μm) was used instead of the TAC film as the anti-reflection base material.

[Example 5]
A polarizing plate with an anti-reflection layer was produced in the same manner as in Example 1, except that a cycloolefin resin film (thickness: 40 μm) was used as the anti-reflection base material instead of the TAC film.

(Comparative example 1)
A polarizing plate with an anti-reflection layer was produced in the same manner as in Example 1, except that the adhesive 4 obtained in Synthesis Example 4 was used for bonding the anti-reflection layer laminate and the polarizer laminate. The obtained polarizing plate was subjected to the same evaluation as in Example 1. Table 1 shows the results.

As is clear from Table 1, the reflection-preventing layer-attached polarizing plates of the examples of the present invention had lower rates of occurrence of peeling of the reflection-preventing layer and wrinkles in a high-temperature, high-humidity environment, as well as an average length, compared to the comparative examples. was markedly suppressed.

The anti-glare layer-attached polarizing plate of the present invention is suitably used for image display devices such as liquid crystal display devices, organic EL display devices and quantum dot display devices.

REFERENCE SIGNS LIST 10 polarizing plate 11 polarizer 12 protective layer 20 anti-reflection layer 30 substrate for anti-reflection layer 40 adhesive layer 100 polarizing plate with anti-reflection layer

Claims (3)

a polarizing plate having a polarizer and a protective layer provided on one side of the polarizer;
a glare-preventing layer, which is an orientation-fixed layer of a liquid crystal compound attached to the protective layer;
a substrate for anti-reflection layer;
A polarizing plate with an anti-reflection layer, comprising an adhesive layer provided between the polarizing plate and the anti-reflection layer,
The pressure-sensitive adhesive layer has a creep value of 40 μm/h or more ,
An antireflection layer, wherein an antireflection layer and a base material for an antireflection layer are further laminated on the base material for the antireflection layer, and the moisture content of the base material for the antireflection layer is 2.0% by weight or more. With polarizer. 2. The polarizing plate with a reflection-preventing layer according to claim 1, further comprising an alignment film between said reflection-prevention layer and said reflection-prevention layer substrate, said alignment film containing a polyvinyl alcohol-based resin. 3. The anti-glare layer-attached polarizing plate according to claim 1, wherein the pressure-sensitive adhesive layer has a thickness of 10 μm to 40 μm.

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