TWI708071B - Polarizing plate and liquid crystal display device - Google Patents

Abstract

If the adhesion force between a protection film and a double-sided tape in a polarizing plate is weak, it would cause a problem that the polarizing plate a separated from a backlight unit due to the impact concentrated on the protection film which is a connection part between the polarizing plate and the backlight unit while the impact is exerted due to moving or dropping in the process. Therefore, a polarizing plate which is capable of preventing peeling of the double-sided tape due to the impact of the moving or dropping in the process after the protection film - ingrated polarizing plate being connected with the backlight unit, and a liquid crystal display device using the same.

Provided is a polarizing plate containing a polarizer, a protection film (A) and a coating layer in this order, wherein the surface of the coating layer far from the polarizer has an average distance of uneven, Sm, of 10 μm or less.

Description

Polarizing plate and liquid crystal display device

The invention relates to a polarizing plate and a liquid crystal display device.

In recent years, mobile terminal devices such as smart phones have gradually become narrower frames in terms of design and portability. In order to cope with the narrower frame of the screen, a method of bonding the back polarizing plate and the backlight plate through a double-sided tape with a width of several mm is adopted. Moreover, usually, the liquid crystal cell and the polarizing plate are bonded through an adhesive before bonding using such a double-sided tape.

In addition, on the backlight side of the rear polarizing plate, a protective film (brightness enhancing film) is laminated. In short, the protective film is bonded to the backlight unit through a double-sided tape. As such a polarizing plate, a protective film-integrated polarizing plate formed by bonding a polarizing plate and a protective film is used.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2002-365430 A

However, as mentioned above, in order to join the protective film integrated polarizer attached to the liquid crystal cell to the backlight unit, when the double-sided tape is directly attached to the protective film on the backlight side of the polarizer, if the protective film and the double-sided tape The adhesion between them is weak, and when they are impacted during transportation or dropping during the manufacturing process, the impact is concentrated on the protective film at the junction of the polarizing plate and the backlight unit, causing the problem of the polarizing plate falling off the backlight unit.

The object of the present invention is to provide a polarizing plate capable of preventing peeling off of the double-sided tape when the protective film integrated polarizing plate and the backlight unit are subjected to impacts such as transportation, dropping, etc., and a liquid crystal using the polarizing plate Display device.

The present invention provides a polarizing plate for the following display and a liquid crystal display device using the polarizing plate.

[1] A polarizing plate comprising a polarizing plate, a protective film (A), and a coating layer in the following order, and the average interval Sm of concavities and convexities on the surface of the coating layer farther from the polarizer is 10 μm or less .

[2] The polarizing plate according to [1], wherein the coating layer contains silicon oxide particles.

[3] The polarizing plate according to [2], wherein the silicon oxide particles are particles whose surfaces have been modified with an organic compound having a polymerizable unsaturated group.

[4] The polarizing plate according to [2] or [3], wherein the weight of the silicon oxide particles The average particle size is 1 to 20 nm.

[5] The polarizing plate according to any one of [1] to [4], wherein the coating layer is a hard coat layer.

[6] The polarizing plate according to any one of [1] to [5], wherein the pencil hardness of the coating layer is HB or more.

[7] The polarizing plate according to any one of [1] to [6], wherein the visual sensitivity correction transmittance of the coating layer is 80% or more.

[8] The polarizing plate according to any one of [1] to [7], wherein the thickness of the polarizer is 30 μm or less.

[9] The polarizing plate according to any one of [1] to [8], wherein the protective film (A) includes a brightness enhancement film.

[10] The polarizing plate according to any one of [1] to [9], wherein the protective film (A) contains a cellulose resin, a (meth)acrylic resin, and a cyclic polyolefin At least one resin in the group consisting of a series resin, a polyester series resin, and a polycarbonate series resin.

[11] The polarizing plate according to any one of [1] to [10], wherein the protective film (A) has an in-plane retardation.

[12] The polarizing plate according to any one of [1] to [11], wherein the polarizer has a protective film (B) on the surface of the polarizer on the far side from the coating layer.

[13] A liquid crystal display device having the polarizing plate described in any one of [1] to [12].

According to the present invention, by providing the protective film at the junction between the liquid crystal cell and the backlight unit, the average interval Sm of the unevenness is less than 10μm. The coating layer can provide a polarizing plate that can effectively prevent the protective film and the double-sided tape from peeling off due to impacts such as transportation and falling during the manufacturing process, and a liquid crystal display device containing the polarizing plate.

10, 50, 60, 70‧‧‧ Polarizing plate

13,53,63,73‧‧‧Polarizer

14, 15, 55, 65, 68, 74‧‧‧Protective film

16, 58, 69, 77‧‧‧Coating layer

17, 56, 57, 66, 67, 72, 76‧‧‧Adhesive layer

20‧‧‧Image display components

30‧‧‧LCD device

40‧‧‧Backlight unit

41‧‧‧Double-sided tape

42‧‧‧Light guide plate

43‧‧‧稜鏡 array sheet

54, 64, 75‧‧‧Brightness enhancement film

Fig. 1 is a schematic cross-sectional view showing an example of the polarizing plate of the present invention and a liquid crystal display device including the polarizing plate.

Fig. 2 is a schematic cross-sectional view showing an example of the polarizing plate of the present invention and a liquid crystal display device including the polarizing plate.

Fig. 3 is a schematic cross-sectional view showing an example of the polarizing plate of the present invention and a liquid crystal display device including the polarizing plate.

Fig. 4 is a schematic cross-sectional view showing an example of the polarizing plate of the present invention and a liquid crystal display device including the polarizing plate.

Fig. 5 is a schematic cross-sectional view showing an example of the polarizing plate of the present invention and a liquid crystal display device including the polarizing plate.

The polarizing plate of the present invention includes a polarizer, a protective film (A), and a coating layer in order. Hereinafter, each member constituting the polarizing plate will be described.

[Polarizer]

The polarizer is preferably an optical film that absorbs linearly polarized light with a vibrating surface parallel to the optical axis, and has the property of transmitting linearly polarized light with a vibrating surface orthogonal to the optical axis. Specifically, Examples include the adsorption and alignment of dichroic pigments (iodine or dichroic organic dyes) on polyvinyl alcohol A polarizer made of resin film.

The polyvinyl alcohol-based resin forming the polyvinyl alcohol-based resin film can be obtained by saponifying a polyvinyl acetate-based resin. Examples of polyvinyl acetate resins include polyvinyl acetate which is a homopolymer of vinyl acetate, and a copolymer of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having ammonium groups, and the like.

The degree of saponification of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be further modified, and polyvinyl methyl acetal and polyvinyl acetal modified with aldehydes can also be used.

The degree of polymerization of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000. As specific polyvinyl alcohol-based resins and dichroic dyes, compounds exemplified in JP 2012-159778 A and the like can be cited.

The film formed by forming the above-mentioned polyvinyl alcohol-based resin into a film can be used as a blank film of a polarizer. The method of forming a polyvinyl alcohol-based resin into a film is not particularly limited, and a known method can be used to form a film. The thickness of the green film made of polyvinyl alcohol-based resin is not particularly limited, and is usually 1 to 150 μm. Considering the ease of extension, the thickness is preferably 3 μm or more.

Polarizers can be manufactured through the following steps: a step of uniaxially stretching a polyvinyl alcohol resin film; using dichroic pigments to polymerize The step of dyeing the vinyl alcohol resin film and making it absorb the dichroic pigment; the step of treating the polyvinyl alcohol resin film after adsorbing the dichroic pigment with the boric acid aqueous solution; the step of washing with water after the treatment with the boric acid aqueous solution; And the drying step. The thickness of the polarizer is usually 2 to 40 μm, preferably 5 to 30 μm.

The polarizer can also be manufactured by the method described in JP 2012-159778 A, etc. The method described in this document does not use a green film composed of the above-mentioned polyvinyl alcohol-based resin, but forms a polyvinyl alcohol-based resin layer by coating a polyvinyl alcohol-based resin on a substrate film and then Stretched and dyed to obtain a polarizer.

[Protective Film (A)]

The protective film (A) is preferably laminated on the polarizer. The protective film (A) preferably contains a transparent thermoplastic resin, and more preferably contains a thermoplastic resin with good mechanical strength and thermal stability. Examples of thermoplastic resins include polyolefin resins such as chain polyolefin resins (polyethylene resins, polypropylene resins, etc.), cyclic polyolefin resins (norbornene resins, etc.); such as fibers Cellulose resins of plain ester resins (cellulose triacetate, cellulose diacetate); such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate Ester resins; (meth)acrylic resins of copolymers of (meth)acrylic resins and (meth)acrylate resins; polystyrene resins; polycarbonate resins; polysulfite resins; polyethers Tungsten resin; polyimide resin, etc. The protective film contains at least one selected from the group consisting of cellulose resin, (meth)acrylic resin, cyclic polyolefin resin, polyester resin, and polycarbonate resin Kind of resin is better.

The protective film (A) may also be a protective film having both optical functions such as a retardation film (optical compensation film) and a brightness enhancement film. As the retardation film, a film formed by uniaxially or biaxially stretching a cyclic polyolefin resin film, etc.; and a film formed by coating a liquid crystal compound on a cellulose resin film, etc. and aligning it film. In addition, the protective film (A) may be a birefringent film. Furthermore, the protective film (A) may be a laminated film of plural protective films.

The in-plane retardation value R _{0 of the} retardation film and the thickness direction retardation value R _th are given by the following formula: R ₀ =(n _x -n _y )×d R _th =[{(n _x +n _y )/ 2}-n _z ]×d definition. The in-plane retardation value R ₀ and the thickness direction retardation value R _th of the retardation film can be adjusted appropriately according to the type of image display element used in the liquid crystal display device. In the above formula, n _x is the refractive index in the in-plane slow axis direction, n _y is the refractive index in the in-plane advance axis direction (the direction orthogonal to the in-plane slow axis direction), and n _z is the refraction in the thickness direction Rate, d is the thickness of the film. When the image display element is an organic EL display element, the retardation film system includes, for example, a 1/4λ plate.

The purpose of the brightness enhancement film is to enhance the brightness of liquid crystal display devices. As the brightness enhancement film, a reflective polarizing separator formed by laminating a plurality of films with different refractive index anisotropies designed to generate anisotropy in reflectance; and supporting on a film substrate Circularly polarized light splitting formed by the alignment film of cholesteric liquid crystal polymer and its alignment liquid crystal layer Off the film and so on. In addition, as the brightness enhancement film, commercial products such as Advanced Polarized Film manufactured by 3M, Version 3 and the like can also be applied.

The thickness of the protective film (A) is usually 5 to 200 μm, preferably 10 to 80 μm, and preferably 10 to 40 μm.

[Protective Film (B)]

The polarizing plate of the present invention includes a polarizer, a protective film (A), and a coating layer in order; it is better to further have a protective film (B) on the side of the polarizer farther from the coating layer. At this time, the polarizing plate has a protective film (B), a polarizer, a protective film (A), and a coating layer in this order. Moreover, the protective film (B) is preferably laminated on the polarizer. As the protective film (B), the same protective film as the protective film (A) described above can be selected.

[Coating layer]

The polarizing plate of the present invention includes a polarizer, a protective film (A), and a coating layer in this order, but the coating layer is preferably provided by joining the protective film (A). The coating layer refers to a layer obtained by applying a coating solution containing resin. The coating layer is preferably formed of (meth)acrylic resin, and may have a single-layer structure or a multilayer structure. Examples of the coating layer include an anti-glare layer, a hard coat layer, a low refractive index layer, an anti-reflection layer, an antistatic layer, an antifouling layer, or a layer having two or more of these functions (characteristics). Especially hard coating is preferred. The surface of the coating layer of the polarizing plate of the present invention on the far side from the polarizing plate satisfies the surface characteristics represented by the following formula (1). Sm is preferably 5 μm or less, and more preferably 4 μm or less. Usually on the side of the coating layer on the far side from the polarizer, the side where the double-sided tape is attached is used for bonding with the backlight unit. (1)Sm≦10

In the formula (1), Sm represents the average interval of unevenness on the surface of the coating layer on the light source side. The unit is μm.

Since the surface of the coating layer on the far side of the polarizer satisfies the above formula (1), the surface of the coating layer has fine surface irregularities. Therefore, after the polarizing plate and the backlight unit are joined, it is possible to prevent handling and transportation during the manufacturing process. Impact such as dropping causes peeling between the coating layer and the double-sided tape and other members.

The average interval Sm of concavities and convexities is defined in accordance with the parameter specified in JIS B 0601: 1994 "Average of valley-period intervals obtained from the intersection of roughness curve and average line" and defined by the following formula.

The Sm system can be measured using a commercially available three-dimensional shape measuring device, roughness meter, etc.

In order to further improve the effect of preventing peeling between the coating layer and the double-sided tape due to impacts such as transportation, dropping, etc., after the polarizing plate and the backlight unit are joined, the coating layer is farther from the polarizer For the surface, the arithmetic average roughness Ra is better than 50nm. The arithmetic average roughness Ra is a parameter specified in 4.2.1 of JIS B 0601:2013, which means the average value of the absolute value of the height Z(x) in the reference length.

The Sm value is well-known in the field of anti-glare films that can be used in anti-glare films that prevent external light from reflecting and shining through surface irregularities. The method to adjust the coating layer can include a method of forming a coating layer from a coating liquid containing particles; and pressing a mold (embossing mold) provided with surface irregularities to contact the coating layer of a light-transmitting resin to form the surface irregularities Transfer method, etc.

As the coating layer of the adjusted Sm value of the polarizing plate of the present invention, a coating layer containing particles is preferred. As a method of forming a coating layer containing particles, a method of applying a coating liquid containing a translucent resin and particles can be mentioned. The coating method of the coating liquid includes a gravure coating method, a micro-gravure coating method, a bar coating method, a knife coating method, an air knife coating method, a roll coating method, a die coating method, and the like.

The particles contained in the coating liquid are preferably light-transmitting particles, and examples include (meth)acrylic resins, melamine resins, polyethylene resins, polystyrene resins, silicone resins, (former Base) organic particles composed of acrylate-styrene copolymer; inorganic particles composed of calcium carbonate, silica, alumina, barium carbonate, barium sulfate, titanium oxide, glass, etc.; balloons of organic polymers; glass Hollow beads. Particles may be used alone or in combination of two or more. In addition, in this specification, the term "(meth)acrylic acid" means at least one selected from the group consisting of acrylic acid and methacrylic acid. The description of "(meth)acrylate" etc. also has the same meaning. Examples of the particle shape include spherical, flat, plate, needle, and indeterminate shapes.

As the particles, silicon oxide particles are preferred. In particular, in terms of forming a strong bond with the light-transmitting resin described later, it is particularly preferable to use silica particles surface-modified with an organic compound having a polymerizable unsaturated group capable of reacting with the light-transmitting resin. Has a polymerizable unsaturated group Silicon oxide particles modified on the surface of an organic compound can be obtained by reacting an organic compound containing a polymerizable unsaturated group with a silanol group on the surface of the silica particle. The organic compound containing a polymerizable unsaturated group is A (meth)acrylic group having a functional group capable of reacting with a silanol group. In addition, in the present invention, the organic compound having a polymerizable unsaturated group modified on the surface of silicon oxide particles may also conform to the light-transmitting resin described later, but the compound modified on the surface of silicon oxide particles is composed of silicon oxide particles. The element is included in the form, and it can be distinguished from the translucent resin described later.

(式中，R¹係表示氫原子或甲基，R²係表示鹵素原子或下述式表示之基)。 Examples of the polymerizable unsaturated group-containing organic compound having a functional group capable of reacting with the aforementioned silanol group include a compound represented by the following formula (I),

(In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents a halogen atom or a group represented by the following formula).

As the compound represented by formula (I), (meth)acrylic acid, chlorinated (meth)acrylic acid, 2-isocyanate ethyl (meth)acrylate, glycidyl (meth)acrylate, ( (Meth) 2,3-iminopropyl acrylate, 2-hydroxyethyl (meth)acrylate, (meth)acryloxypropyl trimethoxysilane And other (meth)acrylic acid derivatives. The organic compound having a polymerizable unsaturated group that modifies the surface of the silicon oxide particles may be used alone or in combination of two or more kinds.

The content of the particles is usually 3 to 60 parts by weight, preferably 3 to 50 parts by weight with respect to 100 parts by weight of the translucent resin described later. When the content of the particles exceeds 60 parts by weight, the transparency of the coating layer obtained is impaired. In addition, when the polarizing plate is applied to the image display device, because the light scattering intensity is too strong, such as black display, the light leaking obliquely to the front direction of the image display device is strongly scattered in the front direction due to the coating layer And there are situations where the contrast is low. In addition, the weight average particle diameter of the particles is preferably 1 nm to 1 μm, preferably 1 to 50 nm, and more preferably 1 to 20 nm. The weight average particle size can be measured with a scanning tunneling microscope.

Examples of the translucent resin contained in the coating liquid include active energy ray curable resins such as ultraviolet curable resins and electron beam curable resins, thermosetting resins, thermoplastic resins, and metal alkoxides. In terms of being able to impart higher hardness and scratch resistance, active energy ray curable resin is preferred.

As an active energy ray curable resin, it is a polyfunctional (meth)acrylate containing (meth)acrylate such as polyol; by reacting hydroxyalkyl (meth)acrylic acid with diisocyanate and polyol The obtained terminal isocyanate group urethane prepolymer reacts to obtain a multifunctional urethane (meth)acrylate. In addition, polyether resins, polyester resins, epoxy resins, alkyd resins, etc. having (meth)acrylate functional groups Spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. can also become active energy ray curable resins.

Examples of thermosetting resins include thermosetting urethane resins composed of acrylic polyols and isocyanate prepolymers, as well as phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, and silicones. Resin etc.

Examples of thermoplastic resins include cellulose derivatives such as cellulose acetate, nitrocellulose, acetyl butyl cellulose, ethyl cellulose, and methyl cellulose; such as homopolymers or copolymers of vinyl acetate. Polyvinyl chloride homopolymer or copolymer, vinylidene chloride homopolymer or copolymer vinyl resin; such as polyvinyl methyl acetal, polyvinyl butyral acetal resin; such as ( (Meth)acrylic resins, (meth)acrylic copolymers (meth)acrylic resins; polystyrene resins; polyamide resins; polyester resins; polycarbonate resins, etc.

As the metal alkoxide, an alkoxysilane-based material can be used, and the metal alkoxide can form a silicon oxide-based matrix by hydrolysis and dehydration condensation. Examples include tetramethoxysilane and tetraethoxysilane.

Among the above-mentioned translucent resins, the active energy ray-curable resin and the thermosetting resin (both of which are the product before curing) are in a liquid state, and the metal alkoxide system is mostly in a liquid state. The resin system in a liquid state can be used as a coating liquid for directly forming a coating layer, but it can also be used as a coating liquid in a state diluted with a solvent or the like as necessary. On the other hand, resins prepared with solid thermoplastic resins are usually The state of being dissolved in an appropriate solvent is preferable as a coating liquid. The coating liquid containing active energy ray curable resin, thermosetting resin, metal alkoxide or thermoplastic resin may also contain appropriate additives such as leveling agents and dispersing agents.

When the coating liquid contains active energy ray-curable resin, the coating liquid contains a photopolymerization initiator.

As the photopolymerization initiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, phenyl ethyl Ketone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2- Methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholine-propane-1- Ketone, 4-(2-hydroxyethoxy)phenyl-2(hydroxy-2-propyl)ketone, diphenylketone, p-phenylbenzophenone, 4,4'-diethylamino diphenyl Ketone, dichlorodiphenyl ketone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary butylanthraquinone, 2-aminoanthraquinone, 2-methyl 9-thioxanthone, 2-ethyl 9-thioxanthone, 2-chloro 9-thioxanthone, 2,4-dimethyl 9-thioxanthone, 2,4-diethyl 9-thioxanthone, benzyl dimethyl acetal Ketones, acetophenone dimethyl ketal, p-dimethylamino benzoate, etc. In addition, these photopolymerization initiators may be used alone or in combination of two or more kinds.

系紫外線吸收劑等。紫外線吸收劑可單獨使用，亦可組合2種以上而使用。以在分子 內具有自由基聚合性雙鍵之自由基聚合性紫外線吸收劑為佳。 When the coating liquid contains an active energy ray-curable resin, the coating liquid may contain an ultraviolet absorber. Examples of ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, hindered amine-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, three

Department of ultraviolet absorbers, etc. The ultraviolet absorber may be used alone or in combination of two or more kinds. It is preferably a radical polymerizable ultraviolet absorber having a radical polymerizable double bond in the molecule.

When the coating liquid contains active energy ray-curable resin, the coating liquid may also contain a light stabilizer. Examples of the light stabilizer include hindered amine-based light stabilizers, benzophenone-based light stabilizers, and benzotriazole-based light stabilizers. The light stabilizer system may be used alone or in combination of two or more kinds.

When the coating layer is provided by joining the protective film (A), the purpose is to improve the coating properties of the coating liquid or the adhesion of the obtained coating layer and the protective film (A), and various surface treatments can also be applied to the coated surface , Used to coat the protective film to form a coating layer. The surface treatment includes corona discharge treatment, glow discharge treatment, acid surface treatment, alkali surface treatment, ultraviolet irradiation treatment, and the like.

In addition, the transmittance of the coating layer is preferably 80% or more, and more preferably 95% or more. Here, the so-called transmittance refers to the transmittance of light with a wavelength of 380 to 780 nm and the transmittance corrected by visual sensitivity. According to the present invention, it is possible to have both the light transmittance of the coating layer and the adhesion to the double-sided tape.

The pencil hardness of the coating layer is preferably B or higher, preferably F or higher, more preferably 2H or higher, and usually 9H or lower. Pencil hardness can be measured in accordance with the pencil hardness test specified in JIS K5600-5-4: 1999 "General Test Methods for Paints-Part 5: Mechanical Properties of Coating Films-Section 4: Scratch Hardness (Pencil Method)" . In a liquid crystal display device, the backlight unit and the polarizing plate with the coating layer are arranged very closely. When the pencil hardness of the coating layer is set to B or higher, the backlight unit can be in contact with the coating layer. Enough to prevent damage to the surface of the polarizer.

[Polarizer]

An example of the configuration of the polarizing plate of the present invention will be described with reference to FIGS. 1 and 3 to 5.

In Figure 1, the polarizer 10 has a polarizer 13 and a coating layer 16. Between the polarizer 13 and the coating layer 16, there is a protective film (A) 14 on the side of the polarizer on the far side of the coating layer. With protective film (B)15. In addition, in order to attach the image display element 20 to the polarizing plate, the polarizing plate 10 is a polarizing plate in which the adhesive layer 17 is laminated on the surface of the protective film 15 farther from the coating layer.

In order to bond the protective film (A) or the protective film (B) to the polarizer, a method of bonding the protective film and the polarizer through an adhesive layer not shown in FIG. 1 can be mentioned.

Examples of the adhesive include water-based adhesives containing polyvinyl alcohol-based resins and urethane resins as main components; and light-curing resins containing light-curing resins such as ultraviolet curable resins (epoxy resins, etc.) Hardening adhesive. Examples of adhesives include adhesives using acrylic polymers, silicone polymers, polyesters, polyurethanes, polyethers, and the like as matrix polymers. The adhesive may also contain particles showing light scattering properties, such as glass fibers, glass beads, resin beads, metal powder and other inorganic powder fillers, pigments, colorants, antioxidants, ultraviolet absorbers, etc. It is also possible to perform easy bonding treatments such as saponification treatment, corona treatment, primer treatment, anchor coating treatment, etc., on the bonding surface of the polarizer and/or the protective film before bonding.

The polarizing plate 50 in Fig. 3 shows the polarization of the brightness enhancement film 54 as the protective film (A) 14 of the polarizing plate shown in Fig. 1 Light board.

In Figure 4, the polarizing plate 60 has a polarizer 63 and a coating layer 69. Between the polarizer 63 and the coating layer 69, from the side close to the polarizer, there is a protective film 68 and a brightness enhancement film 64 and they are combined A protective film (A) is formed. Furthermore, a protective film (B) 65 is provided on the surface of the polarizer on the far side from the coating layer. The protective film 68 and the brightness enhancement film 64 are bonded through the adhesive layer 66. In addition, in order to bond the image display element 20 to the polarizing plate, the polarizing plate 60 is a polarizing plate in which an adhesive layer 67 is laminated on the surface of the protective film (B) 65 on the far side from the coating layer. . In addition, the adhesive layer for bonding the polarizer and the protective films (A) and (B) is not shown.

The polarizer 70 in Figure 5 has a polarizer 73 and a coating layer 77. Between the polarizer 73 and the coating layer 77, from the side close to the polarizer, there is a protective film 74 and a brightness enhancement film 75. And a protective film (A) is formed. The protective film 74 and the brightness enhancement film 75 are bonded through the adhesive layer 76. In addition, in order to bond the image display element 20 to the polarizing plate, the polarizing plate 70 is a polarizing plate in which an adhesive layer 72 is laminated on the surface of the polarizer 73 on the far side from the coating layer. In addition, the adhesive layer for bonding the polarizer and the protective film (A) is not shown.

[Liquid crystal display device]

The polarizing plate of the present invention can be suitably used in various devices such as liquid crystal display devices, and can be particularly suitably used in transmissive and semi-transmissive liquid crystal display devices. Examples of image display elements forming liquid crystal display devices include VA mode, IPS mode, TN mode, FFS mode, AFFS mode, OCB mode, and liquid crystal drive modes using blue phase liquid crystals. Like display components.

Furthermore, in the liquid crystal display device, in addition to the image display element and the polarized light of the present invention, well-known components used in the liquid crystal display device, such as a lens array sheet, a lens array sheet, a light diffusion plate, and a backlight, can also be provided.

When the polarizing plate of the present invention is used in a liquid crystal display device, the polarizing plate of the present invention is preferably arranged on the side of the backlight plate of the image display element, and the coating layer in the polarizing plate is arranged so that the layer closest to the backlight plate For better. Furthermore, the polarizing plate of the present invention can also be arranged on both sides of the image display element.

An example of the configuration of a liquid crystal display device having the polarizing plate of the present invention will be described with reference to FIG. 2. On the backlight side of the image display element 20, the polarizing plate 10 with an adhesive is attached through the adhesive layer 17. In addition, the coating layer 16 of the polarizing plate 10 with the adhesive and the backlight unit 40 can also be bonded by the double-sided tape 41. The backlight plate is provided with a light source (not shown), a light guide plate 42, and an array sheet 43.

[Example]

Hereinafter, examples are shown to explain the present invention more specifically, but the present invention is not limited to these examples. The examples indicate the content or the amount used in% and parts, and they are based on weight unless otherwise stated.

[Manufacturing Example 1]

A cellulose triacetate film with a thickness of 40 μm [trade name "KC4UY" manufactured by Konica Minolta (Co., Ltd.)] was used. On one side of the cellulose triacetate film, silicon oxide particles (weight average particle diameter of 1 to 20 nm) modified with the surface of an organic compound having a polymerizable unsaturated group described in JP-A-9-100111 will be used, and from Shin Nakamura Chemical A mixture of 2 types of acrylic hard-coated resins (product name; A-DCP, UA-1100H) obtained by Kogyo Co., Ltd. was applied using a bar coater and dried in a thermostat at 80°C for 1 minute. With the UV irradiation system made by Fusion UV Systems and the dedicated D valve, the line speed is set to 9.6, the valve height is 45mm, and the UV output is 65%. Then, the UV is irradiated from the coating surface at an exposure rate of 350mJ/cm ² to coat. The hard coat layer is formed by layer, and a cellulose triacetate film with a hard coat layer is obtained. It is F when measuring the pencil hardness of the hard coat layer.

[Manufacturing Example 2]

The brightness enhancement film (Advanced Polarized Film, Version 3 manufactured by 3M) is used. On the polycarbonate surface of the aforementioned brightness enhancement film, a hard coat layer was formed as a coating layer by the same method as in Production Example 1 to obtain a brightness enhancement film having a hard coat layer. It is F when measuring the pencil hardness of the hard coat layer.

[Manufacturing Example 3]

The brightness enhancement film (Advanced Polarized Film, Version 3 manufactured by 3M) is used. On the polycarbonate surface of the aforementioned brightness enhancement film, except for changing the conditions described in Manufacturing Example 1 to 60% UV output and 290 mJ/cm ^{2 of} irradiation, a hard coat layer was formed by the same method as a coating layer. The brightness enhancement film with hard coating is obtained. It is HB when measuring the pencil hardness of the hard coat.

[Manufacturing Example 4]

The brightness enhancement film (Advanced Polarized Film, Version 3 manufactured by 3M) is used. On the polycarbonate surface of the aforementioned brightness enhancement film, except for changing the conditions described in Manufacturing Example 1 to 55% UV output and 230mJ/cm ^{2 of} irradiation, the hard coat layer was formed by the same method as a coating layer. The brightness enhancement film with hard coating is obtained. It is B when measuring the pencil hardness of the hard coat layer.

[Example 1]

A 30μm thick polyvinyl alcohol film (average degree of polymerization of about 2400, saponification degree of 99.9 mol% or more) is uniaxially stretched about 5 times by dry stretching, and then immersed in pure water at 60°C while maintaining tension. After 1 minute, an aqueous solution containing 0.05 part of iodine and 5 parts of potassium iodide was immersed at 28°C for 60 seconds with respect to 100 parts of water. The aqueous solution containing 8.5 parts of potassium iodide and 8.5 parts of boric acid was immersed at 72°C for 300 seconds with respect to 100 parts of water. Next, after washing with pure water at 26°C for 20 seconds, it was dried at 65°C to obtain a polarizer with a thickness of 11 μm in which iodine was adsorbed and aligned on a polyvinyl alcohol film.

Next, 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) is dissolved relative to 100 parts of water, and 1.5 parts of water-soluble epoxy resin is added to the aqueous solution. A water-based epoxy-based adhesive made up of an amide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, an unstretched film made of cycloolefin resin with a thickness of 23μm (trade name "ZEONOR" manufactured by Japan ZEON (Co., Ltd.)) was laminated as a protective film (B). The other side of the polarizer is coated with an adhesive (LINTEC (Stock Co., Ltd.) The brand name "#KZ", acrylic adhesive) manufactured by the company) to form an adhesive layer with a thickness of 20μm. The cellulose triacetate film with a hard coat layer obtained in Production Example 1 and a polarizer were bonded together so that the hard coat layer became the outermost surface of the polarizing plate through the aforementioned adhesive layer to obtain a polarizing plate.

[Example 2]

It carried out similarly to Example 1, and obtained the polarizer.

Next, 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) is dissolved relative to 100 parts of water, and 1.5 parts of water-soluble epoxy resin is added to the aqueous solution. A water-based epoxy-based adhesive made up of an amide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, an unstretched film made of cycloolefin resin with a thickness of 23μm (trade name "ZEONOR" manufactured by ZEON (Co., Ltd.) in Japan) was laminated as a protective film (B). On the other side of the polarizer, an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC Co., Ltd.) was applied to form an adhesive layer with a thickness of 20 μm. The brightness enhancement film with the hard coat layer obtained in Production Example 2 and the polarizer were bonded together so that the hard coat layer became the outermost surface of the polarizing plate through the aforementioned adhesive layer to obtain a polarizing plate.

[Example 3]

It carried out similarly to Example 1, and obtained the polarizer.

Next, dissolve 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) relative to 100 parts of water, and add 1.5 parts of water-soluble epoxy resin to the aqueous solution. Amine epoxy A water-based epoxy-based adhesive composed of an additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., and an aqueous solution with a solid content of 30%), which is coated on one side of the obtained polarizer Moreover, an unstretched film (trade name "ZEONOR" manufactured by ZEON (Co., Ltd.), Japan) with a thickness of 23 μm made of cycloolefin resin was laminated as a protective film (B). On the other side of the polarizer, an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC Co., Ltd.) was applied to form an adhesive layer with a thickness of 20 μm. Through the aforementioned adhesive layer, a cellulose triacetate film (trade name "KC4UY" manufactured by Konica Minolta Co., Ltd.) as a protective film with a thickness of 40 μm was bonded to the polarizer. An adhesive (trade name "#L2", acrylic adhesive manufactured by LINTEC (Co., Ltd.)) was applied to the cellulose triacetate film to form an adhesive layer with a thickness of 5 μm. The brightness enhancement film with the hard coat layer obtained in Production Example 2 was bonded to obtain the polarizing plate by using the hard coat layer as the outermost surface of the polarizing plate through the aforementioned adhesive layer. At this time, the protective film (A) is a laminated film of a cellulose triacetate film and a brightness enhancement film.

[Example 4]

It carried out similarly to Example 1, and obtained the polarizer.

Next, 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) is dissolved relative to 100 parts of water, and 1.5 parts of water-soluble epoxy resin is added to the aqueous solution. A water-based epoxy-based adhesive made up of an amide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, and fit thick A cellulose triacetate film (trade name "KC4UY" manufactured by Konica Minolta Co., Ltd.) with a degree of 40 μm was used as a protective film. An adhesive (trade name "#L2", acrylic adhesive manufactured by LINTEC (Co., Ltd.)) was applied to the cellulose triacetate film to form an adhesive layer with a thickness of 5 μm. The brightness enhancement film with the hard coat layer obtained in Manufacturing Example 2 was bonded by the hard coat layer as the outermost surface of the polarizing plate through the aforementioned adhesive layer, and the other side of the polarizer was coated with an adhesive (LINTEC (Co., Ltd. product name "#KZ", acrylic adhesive) to form an adhesive layer with a thickness of 20 μm to obtain a polarizing plate. At this time, the protective film (A) is a laminated film of a cellulose triacetate film and a brightness enhancement film.

[Example 5]

It carried out similarly to Example 1, and obtained the polarizer.

Next, 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) is dissolved relative to 100 parts of water, and 1.5 parts of water-soluble epoxy resin is added to the aqueous solution. A water-based epoxy-based adhesive made up of an amide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, an unstretched film made of cycloolefin resin with a thickness of 23 μm (trade name "ZEONOR" manufactured by ZEON (Co., Ltd.) in Japan) was laminated as a protective film (B). Moreover, the other side of the polarizer was coated with an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC (Co., Ltd.)) to form an adhesive layer with a thickness of 20 μm. The brightness of the hard coat layer obtained in Manufacturing Example 3 was obtained by using the hard coat layer as the outermost surface of the polarizing plate through the aforementioned adhesive layer The lifting film is bonded to the polarizer to obtain a polarizing plate.

[Example 6]

It carried out similarly to Example 1, and obtained the polarizer.

Next, 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) is dissolved relative to 100 parts of water, and 1.5 parts of water-soluble epoxy resin is added to the aqueous solution. A water-based epoxy-based adhesive made up of an amide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, an unstretched film made of cycloolefin resin with a thickness of 23 μm (trade name "ZEONOR" manufactured by ZEON (Co., Ltd.) in Japan) was laminated as a protective film (B). Moreover, the other side of the polarizer was coated with an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC (Co., Ltd.)) to form an adhesive layer with a thickness of 20 μm. The brightness enhancement film with the hard coat layer obtained in Manufacturing Example 4 and the polarizer were bonded together so that the hard coat layer became the outermost surface of the polarizing plate through the aforementioned adhesive layer to obtain a polarizing plate.

[Manufacturing Example 5]

A cellulose triacetate film with a thickness of 40 μm [trade name "KC4UY" manufactured by Konica Minolta (Co., Ltd.)] was used. On one side of the cellulose triacetate film, two types of acrylic hard-coated resin (product name; A-DCP, UA-1100H) obtained from Shinnakamura Chemical Industry Co., Ltd., which do not contain silica particles, are mixed, It was applied using a bar coater and dried in a thermostat at 80°C for 1 minute. With the UV irradiation system made by Fusion UV Systems and the dedicated D valve, the line speed is set to 9.6, the valve height is 45mm, and the UV output is 65%. Then, the UV is irradiated from the coating surface at an exposure rate of 350mJ/cm ² to coat. The hard coat layer is formed by layer to obtain a cellulose triacetate film with a hard coat layer. When measuring the pencil hardness of the hard coat layer, it was HB or less.

[Manufacturing Example 6]

The brightness enhancement film (Advanced Polarized Film, Version 3 manufactured by 3M) is used. A hard coat layer was formed as a coating layer on the polycarbonate surface of the aforementioned brightness enhancement film by the same method as in Production Example 5 to obtain a brightness enhancement film having a hard coat layer. When measuring the pencil hardness of the hard coat layer, it was HB or less.

[Comparative Example 1]

It carried out similarly to Example 1, and obtained the polarizer.

Next, 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) is dissolved relative to 100 parts of water, and 1.5 parts of water-soluble epoxy resin is added to the aqueous solution. A water-based epoxy-based adhesive made up of an amide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, an unstretched film made of cycloolefin resin with a thickness of 23 μm (trade name "ZEONOR" manufactured by ZEON (Co., Ltd.) in Japan) was laminated as a protective film (B). Moreover, the other side of the polarizer was coated with an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC (Co., Ltd.)) to form an adhesive layer with a thickness of 20 μm. The hard-coating layer obtained in Production Example 5 was obtained by using the hard-coating layer as the outermost surface of the polarizing plate through the aforementioned adhesive layer. The acid cellulose film and the polarizer were bonded together to obtain a polarizing plate.

[Comparative Example 2]

It carried out similarly to Example 1, and obtained the polarizer.

Secondly, 3 parts of modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) dissolved in 100 parts of water and 1.5 parts of water-soluble epoxy resin are added to the aqueous solution. A water-based epoxy-based adhesive composed of a polyamide epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., an aqueous solution with a solid content of 30%) is applied to the On one side of the obtained polarizer, an unstretched film made of cycloolefin resin with a thickness of 23 μm (trade name "ZEONOR" manufactured by Japan ZEON Co., Ltd.) was laminated as a protective film (B). Moreover, the other side of the polarizer was coated with an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC (Co., Ltd.)) to form an adhesive layer with a thickness of 20 μm. The brightness enhancement film with the hard coat layer obtained in Production Example 6 and the polarizer were bonded together so that the hard coat layer became the outermost surface of the polarizing plate through the aforementioned adhesive layer to obtain a polarizing plate.

[Comparative Example 3]

It carried out similarly to Example 1, and obtained the polarizer.

Next, dissolve 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) relative to 100 parts of water, and add 1.5 parts of water-soluble epoxy resin to the aqueous solution. A water-based epoxy-based adhesive composed of an amine epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., and an aqueous solution with a solid content of 30%) is applied to the obtained One side of the polarizer, and a thick fit An unstretched film (trade name "ZEONOR" manufactured by ZEON Co., Ltd.) made of cycloolefin resin with a degree of 23 μm was used as the protective film (B). The other side of the polarizer was coated with an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC Co., Ltd.) to form an adhesive layer with a thickness of 20 μm. A 40 μm-thick cellulose triacetate film (trade name "KC4UY" manufactured by Konica Minolta Co., Ltd.) as a protective film was bonded to the polarizer through the aforementioned adhesive layer. An adhesive (trade name "#L2", acrylic adhesive manufactured by LINTEC Co., Ltd.) was applied to the cellulose triacetate film to form an adhesive layer with a thickness of 5 μm. The brightness enhancement film with the hard coat layer obtained in Production Example 6 was bonded through the aforementioned adhesive layer so that the hard coat layer became the outermost surface of the polarizing plate to obtain a polarizing plate. At this time, the protective film (A) is a laminated film of a cellulose triacetate film and a brightness enhancement film.

[Comparative Example 4]

It carried out similarly to Example 1, and obtained the polarizer.

Next, dissolve 3 parts of carboxyl modified polyvinyl alcohol (trade name "KL-318" obtained from KURARAY (Co., Ltd.)) relative to 100 parts of water, and add 1.5 parts of water-soluble epoxy resin to the aqueous solution. A water-based epoxy-based adhesive composed of an amine epoxy-based additive (trade name "Sumirez Resin 650(30)" manufactured by Taoka Chemical Industry Co., Ltd., and an aqueous solution with a solid content of 30%) is applied to the obtained On one side of the polarizer, a cellulose triacetate film (trade name "KC4UY" manufactured by Konica Minolta Co., Ltd.) with a thickness of 40 μm was laminated as a protective film. Furthermore, an adhesive (manufactured by Lintec Co., Ltd.) was applied to the cellulose triacetate film. Product name "#L2", acrylic adhesive) to form an adhesive layer with a thickness of 5 μm. The brightness enhancement film with a hard coat layer obtained in Production Example 6 was bonded through the aforementioned adhesive layer so that the hard coat layer became the outermost surface of the polarizing plate. And on the other side of the polarizer, an adhesive (trade name "#KZ", acrylic adhesive manufactured by LINTEC Co., Ltd.) was applied to form an adhesive layer with a thickness of 20 μm to obtain a polarizer. At this time, the protective film (A) is a laminated film of a cellulose triacetate film and a brightness enhancement film.

[Determination of surface characteristics]

Using the polarizing plates obtained in Examples 1 to 6 and Comparative Examples 1 to 4, using a three-dimensional microscope "PLμ 2300" manufactured by SENSOFAR, the objective lens was set to 50 times magnification and in confocal mode, and the surface of the coating layer was determined Characteristics (average interval between bumps; Sm). The measurement area is set to 255 μm×185 μm. In addition, in order to prevent warpage of the sample, an optically transparent adhesive was used to measure the state in which the polarizing plate was bonded to the glass substrate (the uneven surface of the coating layer becomes the surface). The results are shown in Table 1.

[Backlight board tape peeling test]

The surface of the polarizing plates obtained in Examples 1 to 6 and Comparative Examples 1 to 4, which is far from the coating layer, was applied with an adhesive on the side of the soda lime glass of 120mm×200mm, and the polarizing plates and the soda lime glass Glass fit. Next, the backlight tape No. 5603BN manufactured by Nitto Denko (Co., Ltd.) was cut into a width of 25 mm and a length of 100 mm, and the adhesive surface of the backlight tape was attached to the coating layer of the polarizer. At this time, make the backlight panel tape extend 30 to 40 mm from the glass. The laminated body with the obtained backlight tape, polarizing plate, and soda lime glass according to the following order, make it at 23℃/50% Maturation in the environment for 24hr.

In the chuck of the AUTOGRAPH (automatic recorder) AGS-50NX type tensile testing machine of Shimadzu Corporation (Co., Ltd.), clamp the backlight plate tape that is 30 to 40 mm beyond the glass in the above laminate in advance. In an environment of 23°C/50%, measure the adhesive strength of the backlight tape when peeling 180 degrees at a tensile speed of 300 mm/min. The results are shown in Table 1.

[Impact test]

The polarizing plates obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were attached to the liquid crystal cell. In addition, the liquid crystal module formed by bonding the coating layer of the polarizing plate and the backlight unit through the backlight plate tape No. 5603BN made by Nitto Denko (Co., Ltd.), the plane of the marble table and the surface of the liquid crystal module (total 6 Faces) overlap each other so that they fall from a height of 150cm. A total of 6 drops on each surface of the liquid crystal module were used to test the adhesion between the back light panel tape and the coating layer interface. When the end of the backlight tape peels off from the coating layer, it is considered that the interface has changed. When the peeling cannot be observed, it is considered that there is no change in the interface. Show the results in Table 1

[Transmittance]

Measure the transmittance (A) of the protective film with the coating layer obtained in Manufacturing Examples 1 and 2, and Manufacturing Examples 5 and 6, and the protective film (brightness enhancement film and triacetate fiber) before applying the coating solution to form the coating layer Plain film) transmittance (B). The transmittance (A) is the relative value when the transmittance (B) is set to 100%. It is measured using a spectrophotometer with integrating sphere (manufactured by JASCO Corporation, V7100). In the wavelength range of 380 to 780nm, the MD transmittance and TD transmittance are calculated, and the single transmittance at each wavelength is calculated based on the formula (1), and the viewing is performed in accordance with the 2 degree field of view (C light source) of JIS Z 8701 The sensitivity is corrected and the visual sensitivity is corrected by calculating the single transmittance (Ty). The results are shown in Table 2.

In the above, the so-called "MD transmittance" refers to the transmittance when the direction of the polarized light emitted from Glan-Thomson is parallel to the transmission axis of the polarizing plate, in the formula (1) system Expressed as "MD". In addition, the so-called "TD transmittance" means the transmittance when the direction of the polarized light emitted from Glan-Thomson (Glan-Thomson) and the transmission axis of the polarizing plate are orthogonal to each other, in the formula (1) system Expressed as "TD".

Monomer transmittance (%)=(MD+TD)/2 formula (1)

Industrial possibilities

According to the present invention, it is possible to provide a polarizing plate that can prevent the double-sided tape from peeling off due to impacts such as transportation, dropping, etc., after joining the protective film integrated polarizing plate attached to the liquid crystal cell to the backlight unit, and using the polarizing plate Polarized liquid crystal display device.

10‧‧‧Polarizer

13‧‧‧Polarizer

14,15‧‧‧Protective film

16‧‧‧Coating layer

17‧‧‧Adhesive layer

20‧‧‧Image display components

30‧‧‧LCD device

Claims (12)

A polarizing plate having a polarizer, a protective film (A), and a coating layer in order. The average interval Sm of unevenness on the surface of the coating layer farther from the polarizer is 10μm or less, and the arithmetic average roughness Ra is 50nm As described above, the coating layer contains light-transmitting particles having a weight average particle diameter of 1 to 20 nm. The polarizing plate according to the first item of the patent application, wherein the light-transmitting particles contain silicon oxide particles. The polarizing plate according to the second item of the scope of patent application, wherein the silica particles are surface-modified particles with an organic compound having a polymerizable unsaturated group. The polarizing plate according to any one of items 1 to 3 in the scope of patent application, wherein the aforementioned coating layer is a hard coat layer. The polarizing plate according to any one of items 1 to 3 in the scope of patent application, wherein the pencil hardness of the coating layer is HB or higher. The polarizing plate according to any one of items 1 to 3 in the scope of patent application, wherein the visual sensitivity correction transmittance of the coating layer is more than 80%. The polarizing plate according to any one of items 1 to 3 in the scope of patent application, wherein the thickness of the aforementioned polarizing plate is 30 μm or less. The polarizing plate according to any one of items 1 to 3 in the scope of patent application, wherein the protective film (A) includes a brightness enhancement film. Such as the polarizing plate described in any one of items 1 to 3 in the scope of patent application, Wherein the aforementioned protective film (A) contains at least one resin selected from the group consisting of cellulose resin, (meth)acrylic resin, cyclic polyolefin resin, polyester resin, and polycarbonate resin . The polarizing plate according to any one of items 1 to 3 in the scope of the patent application, wherein the protective film (A) has an in-plane phase difference. The polarizing plate according to any one of items 1 to 3 in the scope of the patent application, wherein the protective film (B) is provided on the surface of the polarizer on the far side from the coating layer. A liquid crystal display device having a polarizing plate as described in any one of items 1 to 11 in the scope of the patent application.

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