JP2010262094A - Polarizing plate, liquid crystal panel using the same, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate which is arranged between a liquid crystal cell and backlight, the polarizing plate including a polarizing film to which a protection film is bonded with sufficient adhesive strength without causing any problem such as a poor external appearance even if a moisture permeability-lowered resin film is used as the protection film; and to provide a liquid crystal display panel using the polarizing plate and a liquid crystal display device. <P>SOLUTION: The polarizing plate includes; a polarizing film including a uniaxially stretched polyvinyl alcohol-based resin film in which iodine or dichromatic dye is adsorbed and aligned; and a sheet member which is laminated on the polarizing film via an active energy ray curable resin adhesive layer, which includes an epoxy resin, and includes a prism-shaped or lens-shaped surface. The liquid crystal display panel and the liquid crystal display device using the polarizing plate are also provided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polarizing plate, and a liquid crystal panel and a liquid crystal display device using the polarizing plate.

  Applications of liquid crystal display devices are rapidly expanding as thin display devices such as liquid crystal televisions, liquid crystal monitors, and personal computers. In particular, the market for liquid crystal televisions is remarkably expanding, and the demand for cost reduction is very high.

  A normal liquid crystal display device includes a backlight composed of a cold cathode tube or LED, a light diffusion plate, one or a plurality of diffusion sheets, a condensing sheet, and a liquid crystal panel on which a polarizing plate is bonded. In the use of large-screen liquid crystal televisions, the needs for wall-mounted televisions have become apparent due to thinning. In this case, it is necessary to reduce the number of members and the number of members used in response to the thinning of liquid crystal televisions.

  In response to such a request, a method of directly bonding a prism sheet having light condensing properties to one side of a polarizing plate (rear side polarizing plate) disposed between a liquid crystal cell and a backlight (for example, JP-A-11-295714) Gazette (Patent Document 1), International Publication No. 2007/129609 (Patent Document 2), Japanese Patent Application Laid-Open No. 2002-107545 (Patent Document 3), etc.), a protective film for a polarizing film on the backlight side in a liquid crystal display device As a method using a prism sheet having a light collecting property (see, for example, JP-A-2005-17355 (Patent Document 4), JP-A-2008-262133 (Patent Document 5), etc.), See, for example, a method of integrally forming a prism-shaped or lens-shaped light diffusion layer (for example, JP-A-6-34961 (Patent Document 6)). ), The exception of one or more members, techniques to reduce the number of parts is disclosed. Japanese Patent No. 4210053 (Patent Document 7) also discloses a light source device using a prism sheet, although the polarizing plate is not described.

  In the above method, for example, in the method described in Patent Document 4, the polarizing plate is formed on a polarizing film made of a polyvinyl alcohol resin on which a dichroic dye is adsorbed and oriented, for example, with a water-based adhesive layer, for example, triacetyl cellulose. It is the structure which laminated | stacked the hydrophilic condensing film represented by (2) as a protective film of a polarizing film. However, polarizing plates using a triacetyl cellulose film as a protective film are often inferior in heat and moisture resistance and thermal shock resistance, causing deterioration of polarization performance in high temperature and high humidity and high and low temperature repeated environments, and damage to the polarizing film. There was a case.

  The reason why polarizing plates are often inferior in heat and moisture resistance is that the triacetyl cellulose film, which is a constituent element, has high moisture permeability and water absorption, and in order to bond a polarizing film and a protective film that are hydrophilic, Examples of the adhesive generally include water-based adhesives such as polyvinyl alcohol-based adhesives and urethane-based adhesives. Thus, for example, Japanese Patent Application Laid-Open No. 7-77608 (Patent Document 8) discloses means for using a cyclic olefin resin film having a lower moisture permeability and a lower water absorption rate in place of the triacetyl cellulose film.

  However, when a resin film with low moisture permeability is used as the protective film, there are problems such as insufficient adhesive strength being obtained with an aqueous adhesive and poor appearance. This is because a film having a low moisture permeability is generally more hydrophobic than a triacetyl cellulose film, and because the moisture permeability is low, water as a solvent cannot be sufficiently dried.

JP-A-11-295714 International Publication No. 2007/129609 JP 2002-107545 A JP 2005-17355 A JP 2008-262133 A JP-A-6-34961 Patent No. 4210053 JP-A-7-77608

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to achieve a poor appearance with sufficient adhesive strength even when a resin film having low moisture permeability is used as a protective film. To provide a polarizing plate to be disposed between a liquid crystal cell and a backlight, and a liquid crystal panel and a liquid crystal display device using the same, in which a protective film is bonded to a polarizing film without causing problems such as It is in.

  The polarizing plate of the present invention is a polarizing film composed of a uniaxially stretched polyvinyl alcohol-based resin film in which iodine or a dichroic dye is adsorbed and oriented, and an active energy ray-curable resin adhesive layer containing an epoxy resin. And a sheet member having a prism-like or lens-like surface shape laminated on a polarizing film.

  In the polarizing plate of the present invention, the material of the sheet member is polyolefin resin, acrylic resin, polycarbonate resin, polyester resin, polystyrene resin, methyl methacrylate-styrene copolymer, acrylonitrile-butadiene-styrene copolymer. A thermoplastic resin selected from the group consisting of a polymer and an acrylonitrile-styrene copolymer is preferable.

  In the polarizing plate of the present invention, it is preferable that an optical compensation film or a protective film is laminated on the side opposite to the side on which the sheet member of the polarizing film is laminated.

  The polarizing plate of the present invention is preferably used as a back side polarizing plate disposed between a liquid crystal cell and a backlight in a liquid crystal display device.

  The present invention also includes a liquid crystal cell and the polarizing plate of the present invention laminated on the liquid crystal cell, and the polarizing plate has a liquid crystal cell on the opposite side of the polarizing film from the side on which the sheet member is laminated. A liquid crystal panel which is arranged so as to face each other is also provided.

  The present invention further provides a liquid crystal display device including the backlight and the above-described liquid crystal panel of the present invention in this order, and the liquid crystal panel is a liquid crystal in which the sheet member is disposed to face the backlight. A display device is also provided.

  The polarizing plate of the present invention can achieve thinning of the applied liquid crystal panel, and can be thinned by combining this liquid crystal panel and a backlight system. The liquid crystal display device of the present invention using such a polarizing plate of the present invention can be suitably applied to a liquid crystal display device for a large-screen liquid crystal television, particularly a liquid crystal display device for a liquid crystal television that can be wall-mounted.

It is sectional drawing which shows typically the polarizing plate 1 of a preferable example of this invention. It is a figure which shows typically an example in case the surface shape of the sheet | seat member in this invention is prism shape. It is a figure which shows typically the 1st example in case the surface shape of the sheet | seat member in this invention is lens shape. It is a figure which shows typically the 2nd example in case the surface shape of the sheet | seat member in this invention is lens shape. It is a figure which shows typically the 3rd example in case the surface shape of the sheet | seat member in this invention is lens shape. It is a figure which shows typically the 4th example in case the surface shape of the sheet | seat member in this invention is lens shape. It is sectional drawing which shows typically the liquid crystal display device 11 of a preferable example of this invention.

  FIG. 1 is a cross-sectional view schematically showing a polarizing plate 1 as a preferred example of the present invention. As shown in FIG. 1, the polarizing plate 1 of the present invention includes a polarizing film 2 made of a uniaxially stretched polyvinyl alcohol resin film in which iodine or a dichroic dye is adsorbed and oriented, and an active energy ray-curable material containing an epoxy resin. And a sheet member 3 having a prism-like or lens-like surface shape laminated on the polarizing film via a resin adhesive layer 4. Hereinafter, each structure of the polarizing plate of this invention is demonstrated in detail.

(Polarizing film)
Specifically, the polarizing film 2 used in the polarizing plate 1 of the present invention is obtained by adsorbing and orienting a dichroic dye on a uniaxially stretched polyvinyl alcohol resin film. The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate resin. Polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymers. Etc. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. These polyvinyl alcohol resins may be modified. For example, polyvinyl formal, polyvinyl acetal, polyvinyl butyral and the like modified with aldehydes may be used. Moreover, the polymerization degree of polyvinyl alcohol-type resin is in the range of 1000-10000 normally, Preferably it exists in the range of 1500-5000.

  A film obtained by forming such a polyvinyl alcohol resin is used as a raw film of a polarizing film. The method for forming the polyvinyl alcohol-based resin is not particularly limited, and can be formed by a conventionally known appropriate method. Although the film thickness of the raw film which consists of polyvinyl alcohol-type resin is not specifically limited, For example, it is about 10-150 micrometers.

  A polarizing film usually includes a process of dyeing a polyvinyl alcohol resin film with a dichroic dye and adsorbing the dichroic dye (dyeing process), and a polyvinyl alcohol resin film on which the dichroic dye is adsorbed. It is manufactured through a step of treating with an acid aqueous solution (boric acid treatment step) and a step of washing with water after the treatment with the boric acid aqueous solution (water washing treatment step).

  In the production of the polarizing film, the polyvinyl alcohol-based resin film is usually uniaxially stretched, but this uniaxial stretching may be performed before the dyeing treatment step or during the dyeing treatment step, It may be performed after the dyeing process. When uniaxial stretching is performed after the dyeing treatment step, the uniaxial stretching may be performed before the boric acid treatment step or during the boric acid treatment step. Of course, uniaxial stretching can be performed in these plural stages. Uniaxial stretching may be performed uniaxially between rolls having different peripheral speeds, or may be performed uniaxially using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 3 to 8 times.

  Dyeing of the polyvinyl alcohol resin film with the dichroic dye in the dyeing process is performed, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye. As the dichroic dye, for example, iodine, a dichroic dye or the like is used. Examples of dichroic dyes include C.I. I. Dichroic direct dyes composed of disazo compounds such as DIRECT RED 39 and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo are included. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

  When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye, the temperature of the aqueous solution used for dyeing is usually 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 20 to 1800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution, usually, 1 × 10 ^-4 to 10 parts by weight per 100 parts by weight of water, preferably 1 × 10 ^-3 to 1 parts by weight, particularly preferably 1 × 10 ^{- 3} to 1 × 10 ⁻² parts by weight. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. When using a dichroic dye as the dichroic dye, the temperature of the aqueous dye solution used for dyeing is usually 20 to 80 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 10 to 1800 seconds. is there.

  The boric acid treatment step is performed by immersing a polyvinyl alcohol-based resin film dyed with a dichroic dye in a boric acid-containing aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye in the dyeing process described above, the boric acid-containing aqueous solution used in this boric acid treatment process preferably contains potassium iodide. In this case, the amount of potassium iodide in the boric acid-containing aqueous solution is usually 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

  In the subsequent washing process, the polyvinyl alcohol-based resin film after the boric acid treatment described above is washed with water, for example, by immersing it in water. The water temperature in the water washing treatment is usually 5 to 40 ° C., and the immersion time is usually 1 to 120 seconds. After the water washing treatment, a drying treatment is usually performed to obtain a polarizing film. The drying process is preferably performed using, for example, a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually 30 to 100 ° C, preferably 50 to 80 ° C. The time for the drying treatment is usually 60 to 600 seconds, preferably 120 to 600 seconds.

  In this way, the polyvinyl alcohol resin film is uniaxially stretched, dyed with a dichroic dye, treated with boric acid and washed with water to obtain a polarizing film. The thickness of this polarizing film is usually in the range of 5 to 40 μm.

(Sheet material)
The sheet member 3 used in the polarizing plate 1 of the present invention has a prism-like or lens-like surface shape. Thus, by making the surface shape of the sheet member 3 into a prism shape or a lens shape, a function of intentionally changing (deflecting) the direction of light can be given to the surface or the inside thereof. The sheet member 3 serves as a protective film.

  Here, the “prism shape” mainly refers to a shape in which a plane or a curved surface indicated by a locus obtained by translating a shape made of a triangular straight line (which may include a curve) is arranged in one direction. As an example of such a prism shape, for example, a shape in which planes indicated by a locus obtained by translating an isosceles triangle are arranged in one direction as shown in FIG. Also, the triangular cross section in the prism shape may include a curve as described above. For example, the shape of a saw blade or a shape in which the apex of the triangular cross section is rounded is included in the prism shape. Is done. Furthermore, the “prism shape” referred to in the present invention is not strictly included in the above definition, but includes a wave shape such as a sine wave in its cross section.

  When the surface shape of the sheet member 3 is prismatic, the apex angles of the adjacent triangular cross-sections are preferably within a range of 30 to 100 ° in order to collect light incident on the prism. More preferably, it is in the range of ˜75 °. In addition, when the surface shape of the sheet member 3 is a prism shape, the height of the adjacent triangular cross sections (the linear distance along the vertical direction between the bottom surface and the apex) is easy to handle the sheet member 3. Therefore, it is preferable to be within the range of 10 to 200 μm. In addition, the pitch of the cross-sectional triangles adjacent to each other (the linear distance along the direction parallel to the bottom surface between the vertices) is preferably in the range of 5 to 300 μm in order to satisfy the apex angle and height. .

  In addition, when the surface shape of the sheet member 3 is a prism shape, the above-described apex angle, pitch, and height may be different from each other between the adjacent triangular cross-sections as long as they are within the above-described ranges. . Further, in the present invention, when the surface shape of the sheet member 3 is a prism shape, the grooves between the adjacent triangular cross sections may be straight lines as shown in FIG. The part may be a curve.

  In addition, the “lens shape” in the present invention refers to a shape in which curved surfaces or planes indicated by a locus obtained by translating a shape made of an arcuate curve (which may include a straight line) are arranged in one direction, or A dome-shaped curved surface having a bottom surface such as a circular shape (which may be a perfect circle or an ellipse), a rectangular shape (which may be a square shape or a rectangular shape), a triangular shape, or a hexagonal shape. Mainly refers to a shape in which are arranged vertically and horizontally. As an example of such a lens shape, for example, a shape in which curved surfaces indicated by trajectories obtained by translating arc shapes as shown in FIG. 3 are arranged in one direction (specifically, using a lenticular lens sheet or the like). 4. A shape in which dome-shaped curved surfaces having a circular bottom surface as shown in FIG. 4 are arranged vertically and horizontally (specifically, using a two-dimensional lens array sheet), and a rectangular bottom surface as shown in FIG. And the like (specifically, using a two-dimensional lens array sheet). In addition, the lens shape referred to in the present invention is not strictly included in the above definition, but a polyhedral shape in which planes having various angles as shown in FIG. 6 are combined (in the example shown in FIG. A structure in which many pyramidal pyramid structures are arranged) and a so-called Fresnel lens or a deformed shape thereof are also included.

  When the surface shape of the sheet member 3 is a lens shape, the pitches of the cross-sectional arc shapes adjacent to each other (the linear distance along the direction parallel to the bottom surface between the vertices) are in the range of 10 to 200 μm, and It is preferable that the height of the adjacent arc-shaped cross sections (the linear distance along the vertical direction between the bottom surface and the apex) is in the range of 5 to 100 μm.

  In addition, when the surface shape of the sheet | seat member 3 is a lens shape, as long as it is in the range mentioned above, the pitch and height mentioned above may mutually differ between each cross-sectional arc shape adjacent to each other. Furthermore, in the present invention, when the surface shape of the sheet member 3 is a so-called lenticular lens shape, the grooves between the adjacent arcs of the cross sections may be straight lines as shown in FIG. At least a part may be a curve.

  Various known materials can be used as the material of the sheet member. For example, polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate resin and polyethylene naphthalate resin, polyvinyl chloride resins, polycarbonate resins, norbornene resins, polyurethane resins, acrylic resins, polymethyl methacrylate resins , Synthetic polymers such as polystyrene resin, methyl methacrylate-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, natural diacetate resin, cellulose triacetate resin, etc. Polymers can be used. Among them, from the viewpoint of transparency, moisture permeability and productivity, polyolefin resin, polyacrylic resin, polycarbonate resin, polyester resin, polystyrene resin, methyl methacrylate-styrene copolymer, acrylonitrile-butadiene-styrene Any one of a thermoplastic copolymer and an acrylonitrile-styrene copolymer is suitable. These polymer materials can contain additives such as ultraviolet absorbers, antioxidants, and plasticizers as necessary.

  The sheet member 3 is made of such a transparent polymer material as a base material, such as a photopolymer process method, a profile extrusion method, a press molding method, an injection molding method, a roll transfer method, a laser ablation method, a mechanical cutting method, a mechanical grinding method, etc. It can manufacture by a well-known method, These methods can be used individually, respectively, or can be used combining 2 or more types of methods.

  The thickness of the sheet member 3 is not particularly limited, but is preferably in the range of 20 to 200 μm, and more preferably in the range of 30 to 100 μm.

  The sheet member 3 and the polarizing film 2 are laminated via an active energy ray-curable resin adhesive layer 4 containing an epoxy resin. The sheet member 3 may be laminated with the prism-like or lens-like surface shape side facing the polarizing film 2 side, or the prism-like or lens-like surface shape side is opposite to the polarizing film 2. You may laminate | stack so that it may arrange | position. In order to make the adhesiveness between the sheet member 3 and the polarizing film 2 stronger, it is preferable to dispose the adhesive layer 4 on the flat surface of the sheet member 3. It is preferable to laminate so that the side having the surface shape is disposed on the side opposite to the polarizing film 2.

  Known active energy ray-curable resin adhesives containing epoxy resins are used. In the present invention, a polarizing plate exhibiting sufficient adhesive strength and excellent reliability can be obtained by using an active energy ray-curable resin adhesive containing an epoxy resin. The epoxy resin refers to a compound or polymer having an average of two or more epoxy groups in a molecule and cured by reaction. In accordance with common practice in this field, in the present specification, any monomer having two or more curable epoxy groups in its molecule is referred to as an epoxy resin.

  As the epoxy resin, an epoxy resin that does not contain an aromatic ring in the molecule is suitably used from the viewpoints of weather resistance, refractive index, cationic polymerizability, and the like. Examples of such epoxy resins include hydrogenated epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins.

  As for the hydrogenated epoxy resin, this can be obtained by selectively hydrogenating an aromatic epoxy resin in the presence of a catalyst under pressure. Examples of aromatic epoxy resins include bisphenol type epoxy resins such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S; phenol novolac epoxy resins, cresol novolac epoxy resins, hydroxybenzaldehyde Examples include novolak-type epoxy resins such as phenol novolac epoxy resins; glycidyl ethers of tetrahydroxyphenylmethane, glycidyl ethers of tetrahydroxybenzophenone, and epoxidized polyvinylphenol. Although the hydrogenated epoxy resin of these aromatic epoxy resins becomes a hydrogenated epoxy resin, it is preferable to use hydrogenated bisphenol A glycidyl ether.

An alicyclic epoxy compound means an epoxy compound having at least one epoxy group bonded to an alicyclic ring. The “epoxy group bonded to the alicyclic ring” has a structure in which one or more hydrogen atoms in (CH ₂ ) _m are removed from the following formula. In formula, m is an integer of 2-5.

  -Epoxycyclohexylmethyl epoxycyclohexanecarboxylates corresponding to the following formula (I):

(In the above formula (I), R ₁ and R ₂ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.)
-Epoxycyclohexanecarboxylates of alkanediol corresponding to the following (II):

(In the above formula (II), R ₃ and R ₄ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and n represents an integer of 2 to 20)
-Epoxycyclohexyl methyl esters of dicarboxylic acids corresponding to the following formula (III):

(In the above formula (III), R ₅ and R ₆ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and p represents an integer of 2 to 20).
-Epoxycyclohexyl methyl ethers of polyethylene glycol corresponding to the following formula (IV):

(In the above formula (IV), R ₇ and R ₈ independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and q represents an integer of 2 to 10).
-Epoxycyclohexyl methyl ethers of alkanediols corresponding to the following formula (V):

(In the above formula (V), R ₉ and R ₁₀ independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms, and r represents an integer of 2 to 20).
A diepoxy trispiro compound corresponding to the following formula (VI):

(In the formula (VI), R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.)
A diepoxy monospiro compound corresponding to the following formula (VII):

(In the formula (VII), R ₁₃ and R ₁₄ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.)
-Vinylcyclohexene diepoxides corresponding to the following formula (VIII):

(In the above formula (VIII), R ₁₅ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.)
-Epoxycyclopentyl ethers corresponding to the following formula (IX):

(In the formula (IX), R ₁₆ and R ₁₇ each independently represent a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.)
-Diepoxy tricyclodecanes corresponding to the following formula (X):

(In the above formula (X), R ₁₈ represents a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms.)
Among these, preferred examples of the alicyclic epoxy compound include 7-oxabicyclo [4.1.0] heptane-3-carboxylic acid and (7-oxabicyclo [4.1.0] hept. 3-yl) in ester of methanol (the above formula (I), the compounds of _{R 1 = R 2 = H)} , 4- methyl-7-oxabicyclo [4.1.0] heptane-3-carboxylic acid And (4-methyl-7-oxabicyclo [4.1.0] hept-3-yl) methanol (in the above formula (I), R ₁ = 4-CH ₃ , R ₂ = 4-CH ₃ compounds), the 7-oxabicyclo [4.1.0] heptane-3-carboxylic acid and 1,2-ethanediol and the ester (the formula _{(II), R 3 = R} 4 = H, n = 2 compound), (7-oxabicyclo [4.1. ] Hept-3-yl) in ester of methanol and adipic acid (the formula _{(III), R 5 = R} 6 = H, compounds of p = 4), (4-methyl-7-oxabicyclo [4. 1.0] hept-3-yl) esterified product of methanol and adipic acid (in the above formula (III), R ₅ = 4-CH ₃ , R ₆ = 4-CH ₃ , p = 4 compound), ( 7-oxabicyclo [4.1.0] hept-3-yl) methanol and 1,2-ethanediol ether compound [in the above formula (V), R ₉ = R ₁₀ = H, r = 2 compound ) And the like.

  Examples of the aliphatic epoxy compounds include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof. Specifically, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol Polyether polyol obtained by adding one or more alkylene oxides (ethylene oxide, propylene oxide, etc.) to an aliphatic polyhydric alcohol such as diglycidyl ether, ethylene glycol, propylene glycol or glycerin Examples thereof include glycidyl ether.

  The epoxy compounds exemplified here may be used alone, or a plurality of epoxy compounds may be mixed and used.

  The epoxy equivalent of the epoxy compound used in the present invention is usually 30 to 3000 g / equivalent, preferably 50 to 1500 g / equivalent. When the epoxy equivalent is less than 30 g / equivalent, the flexibility of the protective film after curing may be lowered, or the adhesive strength may be reduced. On the other hand, when it exceeds 3000 g / equivalent, compatibility with other components may be lowered.

  In the present invention, cationic polymerization is preferably used as the curing reaction of the epoxy resin from the viewpoint of reactivity. For that purpose, it is preferable to mix a cationic polymerization initiator. The cationic polymerization initiator generates a cationic species or a Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and starts an epoxy group polymerization reaction. Regardless of the type of cationic polymerization initiator, it is preferable from the viewpoint of workability that latency is imparted.

  By using a cationic photopolymerization initiator, it becomes possible to form a sheet member and a protective film at room temperature (25 ° C.), and the necessity of considering the distortion due to heat resistance or expansion of the polarizing film is reduced. There is an advantage that can be bonded well. In addition, since the photocationic polymerization initiator acts catalytically by light, it is excellent in storage stability and workability even when mixed with an epoxy compound. Examples of compounds that generate cation species and Lewis acids upon irradiation with active energy rays include onium salts such as aromatic diazonium salts, aromatic iodonium salts and aromatic sulfonium salts, and iron-allene complexes. It is not limited to.

  Examples of the aromatic diazonium salt include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

  Examples of the aromatic iodonium salt include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di (4-nonylphenyl) iodonium hexafluorophosphate.

  Examples of the aromatic sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, 4,4′-bis [diphenylsulfonio] diphenyl sulfide bis. Hexafluorophosphate, 4,4′-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide Bishexafluoroantimonate, 4,4′-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenyl sulfide Bishexafluorophosphate, 7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone hexafluoroantimonate, 7- [di (p-to Yl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate, 4-phenylcarbonyl-4'-diphenylsulfonio-diphenyl sulfide hexafluorophosphate, 4- (p-tert-butylphenylcarbonyl) -4'- Examples include diphenylsulfonio-diphenylsulfide hexafluoroantimonate, 4- (p-tert-butylphenylcarbonyl) -4′-di (p-toluyl) sulfonio-diphenylsulfide tetrakis (pentafluorophenyl) borate.

  Examples of iron-allene complexes include xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, xylene-cyclopentadienyl iron (II) -tris ( (Trifluoromethylsulfonyl) methanide and the like.

  These cationic photopolymerization initiators may be used alone or in combination of two or more. Among these, aromatic sulfonium salts are particularly preferably used because they have ultraviolet absorption characteristics even in a wavelength region of 300 nm or more, and therefore can provide a cured product having excellent curability and good mechanical strength and adhesive strength. It is done.

  These photocationic polymerization initiators can be easily obtained as commercial products. Specifically, Kayrad PCI-220 (manufactured by Nippon Kayaku Co., Ltd.), Kayarad PCI-620 (manufactured by Nippon Kayaku Co., Ltd.), UVI -6990 (manufactured by Union Carbide), Adeka optomer SP-150 (manufactured by ADEKA), Adeka optomer SP-170 (manufactured by ADEKA), CI-5102 (manufactured by Nippon Soda Co., Ltd.), CIT -1370 (manufactured by Nippon Soda Co., Ltd.), CIT-1682 (manufactured by Nippon Soda Co., Ltd.), CIP-1866S (manufactured by Nippon Soda Co., Ltd.), CIP-2048S (manufactured by Nippon Soda Co., Ltd.), CIP-2064S (Nippon Soda Co., Ltd.), DPI-101 (Midori Chemical Co., Ltd.), DPI-102 (Midori Chemical Co., Ltd.), DPI-103 (Midori Chemical Co., Ltd.), DPI-1 5 (Midori Chemical Co., Ltd.), MPI-103 (Midori Chemical Co., Ltd.), MPI-105 (Midori Chemical Co., Ltd.), BBI-101 (Midori Chemical Co., Ltd.), BBI-102 ( Midori Kagaku), BBI-103 (Midori Kagaku), BBI-105 (Midori Kagaku), TPS-101 (Midori Kagaku), TPS-102 (Midori Kagaku) ), TPS-103 (manufactured by Midori Chemical Co., Ltd.), TPS-105 (manufactured by Midori Chemical Co., Ltd.), MDS-103 (manufactured by Midori Chemical Co., Ltd.), MDS-105 (manufactured by Midori Chemical Co., Ltd.) )), DTS-102 (manufactured by Midori Chemical Co., Ltd.), DTS-103 (manufactured by Midori Chemical Co., Ltd.), PI-2074 (manufactured by Rhodia), and the like. Among these, CI-5102 (manufactured by Nippon Soda Co., Ltd.) is one preferred initiator.

  The compounding quantity of a photocationic polymerization initiator is 0.5-20 weight part normally with respect to 100 weight part of epoxy resins, Preferably it is 1 weight part or more, Preferably it is 15 weight part or less. When the amount is less than 0.5 parts by weight per 100 parts by weight of the epoxy resin, curing becomes insufficient, and mechanical strength and adhesive strength are lowered. In addition, when the amount exceeds 20 parts by weight per 100 parts by weight of the epoxy resin, the ionic substance in the cured product is increased, so that the hygroscopic property of the cured product is increased, and the durability performance may be reduced. It is not preferable.

  Furthermore, a photosensitizer can be used in combination as necessary. By using a photosensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the cured product can be improved. Examples of the photosensitizer include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreductive dyes. Specific photosensitizers include, for example, benzoin derivatives such as benzoin methyl ether, benzoin isopropyl ether, α, α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4-dichlorobenzophenone, o-benzoylbenzoic acid. Benzophenone derivatives such as methyl, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone; 2-chloroanthraquinone, Anthraquinone derivatives such as 2-methylanthraquinone; acridone derivatives such as N-methylacridone and N-butylacridone; other, α, α-diethoxyacetophenone, benzyl, fluorenone, quinone Sandton, uranyl compounds, halogen compounds and the like can be mentioned, but are not limited thereto. These may be used alone or in combination. The photosensitizer is preferably contained in the range of 0.1 to 20 parts by weight when the active energy ray-curable resin adhesive containing an epoxy resin is 100 parts by weight.

  The active energy ray-curable resin adhesive containing an epoxy resin in the present invention may further contain a compound that promotes cationic polymerization, such as oxetanes and polyols.

  Oxetanes are compounds having at least one oxetane ring (four-membered ether) in the molecule, such as 3-ethyl-3-hydroxymethyloxetane, 1,4-bis [(3-ethyl-3- Oxetanyl) methoxymethyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, di [(3-ethyl-3-oxetanyl) methyl] ether, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, Phenol novolac oxetane etc. are mentioned. These oxetanes can be easily obtained as commercial products. Specifically, Aron oxetane OXT-101 (manufactured by Toagosei Co., Ltd.), Aron oxetane OXT-121 (manufactured by Toagosei Co., Ltd.) Aron Oxetane OXT-211 (manufactured by Toagosei Co., Ltd.), Aron Oxetane OXT-221 (manufactured by Toagosei Co., Ltd.), Aron Oxetane OXT-212 (manufactured by Toagosei Co., Ltd.), and the like. Moreover, these oxetanes are used normally in the ratio of 5-95 weight% in the active energy ray-curable resin adhesive containing an epoxy resin, Preferably it is 30-70 weight%.

  As the polyols, those having no acidic groups other than phenolic hydroxyl groups are preferable. For example, polyol compounds having no functional groups other than hydroxyl groups, polyester polyol compounds, polycaprolactone polyol compounds, polyol compounds having phenolic hydroxyl groups, polycarbonates A polyol etc. can be mentioned. The molecular weight of these polyols is usually 48 or more, preferably 62 or more, more preferably 100 or more, and preferably 1000 or less. The blending amount of these polyols is usually 50% by weight or less, preferably 30% by weight or less in the active energy ray-curable resin adhesive containing an epoxy resin.

  Furthermore, other additives such as an ion trap agent, an antioxidant, a chain transfer agent, a sensitizer, and an adhesive are used for the active energy ray-curable resin adhesive containing an epoxy resin unless the effects of the present invention are impaired. An imparting agent, a thermoplastic resin, a filler, a flow regulator, a plasticizer, an antifoaming agent, and the like can be blended. Examples of the ion trapping agent include powdery bismuth-based, antimony-based, magnesium-based, aluminum-based, calcium-based, titanium-based and mixed compounds thereof, and examples of the antioxidant include hinders. Dophenol-based antioxidants and the like are included.

  As in the example shown in FIG. 1, the polarizing plate 1 of the present invention has an adhesive layer or a pressure-sensitive adhesive layer (adhesive in the example shown in FIG. 1) on the side opposite to the side on which the sheet member 3 of the polarizing film 2 is laminated. It is preferable that an optical compensation film or a protective film (protective film 5 in the example shown in FIG. 1) is laminated via an agent layer 6). Moreover, an optical compensation film or a protective film may be laminated on the surface of the polarizing film opposite to the surface on which the sheet member is bonded, and an adhesive or pressure-sensitive adhesive layer may be formed thereon. Furthermore, an optical functional film described later can be laminated on the protective film, and an adhesive or pressure-sensitive adhesive layer can be formed on the optical functional film.

  Examples of the optical compensation film and the protective film include cellulose films such as a triacetyl cellulose film (TAC film), olefin films, acrylic resin films, and polyester films such as polyethylene terephthalate.

  The cellulose-based resin film used in the polarizing plate of the present invention is a cellulose partially or completely esterified film, for example, a film made of cellulose acetate, propionate, butyrate, mixed ester thereof, or the like. Can be mentioned. More specifically, a triacetyl cellulose film, a diacetyl cellulose film, a cellulose acetate propionate film, a cellulose acetate butyrate film, and the like can be given. As such a cellulose ester film, suitable commercially available products such as Fujitac TD80 (manufactured by Fuji Film Co., Ltd.), Fujitac TD80UF (manufactured by Fuji Film Co., Ltd.), Fujitac TD80UZ (manufactured by Fuji Film Co., Ltd.), KC8UX2M (Manufactured by Konica Minolta Opto), KC8UY (manufactured by Konica Minolta Opto), and the like.

  Moreover, as an optical compensation film comprising a cellulose resin film, for example, a film containing a cellulose film containing a compound having a retardation adjusting function, a film obtained by applying a compound having a retardation adjusting function to the surface of a cellulose film, Examples thereof include a film obtained by uniaxially stretching or biaxially stretching a cellulose film. Examples of commercially available cellulose-based optical compensation films include WV film WVBZ438 (manufactured by FUJIFILM Corporation), WV film wide view EA (manufactured by FUJIFILM Corporation), and KC4FR-1 (manufactured by Konica Minolta Opto Corporation). , KC4HR-1 (manufactured by Konica Minolta Opto Co., Ltd.) and the like.

  When such a cellulose resin is formed into a film, a known method such as a solvent casting method or a melt extrusion method is appropriately used.

  The thickness of the optical compensation film comprising the cellulose resin film used in the present invention is not particularly limited, but is preferably in the range of 20 to 90 μm, and more preferably in the range of 30 to 90 μm. When the thickness of the film is less than 20 μm, it is difficult to handle the film. On the other hand, when the thickness of the film exceeds 90 μm, the workability is inferior and the weight of the obtained polarizing plate increases. There is a possibility that.

  Furthermore, a cycloolefin resin film may be uniaxially stretched or biaxially stretched to form an optical compensation film. When the polarizing plate of the present invention is used for a liquid crystal panel for a large-sized liquid crystal television, particularly a liquid crystal panel having a vertical alignment (VA) mode liquid crystal cell, the above-mentioned optical compensation film is a stretched product of a cycloolefin resin film, It is also suitable from the viewpoint of optical characteristics and durability. Here, the cycloolefin resin film is a film made of a thermoplastic resin having a unit of a monomer made of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene monomer. The cycloolefin-based film may be a hydrogenated product of a ring-opening polymer using a single cycloolefin or a ring-opening copolymer using two or more kinds of cycloolefins. It may also be an addition copolymer with an aromatic compound having a vinyl group. Further, those having a polar group introduced into the main chain or side chain are also effective.

Cycloolefin-based resins may be commercial products such as Topas (manufactured by Ticona), Arton (manufactured by JSR Corporation), ZEONOR (manufactured by Nippon Zeon Co., Ltd.), ZEONEX (manufactured by Nippon Zeon Corporation). ) And Apel (Mitsui Chemicals) can be preferably used. When forming such a cycloolefin-based resin into a film, a known method such as a solvent casting method or a melt extrusion method is appropriately used. In addition, for example, escina (manufactured by Sekisui Chemical Co., Ltd.), SCA40 (manufactured by Sekisui Chemical Co., Ltd.), ZEONOR film (manufactured by Nippon Zeon Co., Ltd.), arton film (manufactured by JSR Corporation), etc. Commercially available cycloolefin resin film may be used as a transparent protective film. If the thickness of the stretched cycloolefin resin film is too thick, the processability will be inferior and the transparency will decrease. Or a problem that the weight of the polarizing plate increases. Therefore, the thickness of the stretched cycloolefin resin film is preferably about 20 to 80 μm.

  An optical functional film may be attached to the side opposite to the sheet member side of the polarizing plate. As an optical functional film, for example, a liquid crystal compound is coated on the surface of a base material, an optical compensation film that is oriented, a reflective type that transmits polarized light of some kind and reflects polarized light that shows the opposite property. Polarizing film, retardation film made of polycarbonate-based resin, retardation film made of cyclic polyolefin-based resin, film with an anti-glare function having a concavo-convex shape on the surface, film with a surface anti-reflection function, reflecting film having a reflecting function on the surface, Examples thereof include a transflective film having both a reflection function and a transmission function. Commercially available products corresponding to the optical compensation film in which a liquid crystal compound is coated on the substrate surface and oriented include WV film (manufactured by FUJIFILM Corporation), NH film (manufactured by Nippon Oil Corporation), NR Examples include films (manufactured by Nippon Oil Corporation). For example, DBEF (manufactured by 3M, available from Sumitomo 3M Co., Ltd. in Japan) is a commercially available product corresponding to a reflective polarizing film that transmits certain types of polarized light and reflects polarized light that exhibits the opposite properties. , APF (manufactured by 3M, available from Sumitomo 3M Co., Ltd. in Japan) and the like. Moreover, as a commercial item equivalent to the phase difference film which consists of cyclic polyolefin resin, for example, Arton Film (made by JSR Corporation), Essina (made by Sekisui Chemical Co., Ltd.), Zeonore Film (made by Nippon Zeon Corporation) ) And the like.

  The active energy ray-curable resin adhesive containing the epoxy resin described above can also be suitably used for bonding the polarizing film and the protective film or the optical compensation film. In this case, there is no particular limitation on the method of applying the adhesive to at least one of the polarizing film, the sheet member, the protective film, and the optical compensation film. For example, a doctor blade, a wire bar, a die coater, a comma coater, a gravure coater, etc. Various coating methods can be used. In addition, since each coating method has an optimum viscosity range, it is also a useful technique to adjust the viscosity using a solvent. As the solvent for this purpose, a solvent that can satisfactorily dissolve the active energy ray-curable resin adhesive containing the epoxy resin described above without decreasing the optical performance of the polarizing film is used. There is no limitation. For example, organic solvents such as hydrocarbons typified by toluene and esters typified by ethyl acetate can be used. The thickness of the adhesive layer is usually 50 μm or less, preferably 20 μm or less, more preferably 10 μm or less.

  The sheet member, the protective film, and the optical compensation film may be subjected to easy adhesion treatment such as corona treatment, primer treatment, and anchor coating treatment on the bonding surface prior to bonding to the polarizing film. Moreover, you may have various process layers, such as a hard-coat layer, an antireflection layer, and a glare-proof layer, in the surface on the opposite side to the bonding surface to the polarizing film of a protective film and an optical compensation film. The thickness of the protective film and the optical compensation film is usually in the range of about 5 to 200 μm, preferably 10 to 120 μm, and more preferably 10 to 85 μm.

  As described above, the polarizing film to which the sheet member, the protective film, and the optical compensation film are bonded via the active energy ray-curable resin adhesive containing the uncured epoxy resin is then irradiated with the active energy ray. Thus, the active energy ray-curable resin adhesive layer is cured, and the sheet member, the protective film, and the optical compensation film are fixed on the polarizing film.

The light source used for polymerization curing by irradiation with active energy rays is not particularly limited, but has a light emission distribution at a wavelength of 400 nm or less, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, a black light A lamp, a microwave excitation mercury lamp, a metal halide lamp, or the like can be used. The light irradiation intensity to the active energy ray-curable resin adhesive containing the epoxy resin is determined for each target composition and is not particularly limited, but is a wavelength effective for activation of the initiator. The irradiation intensity of the region is preferably 0.1 to 100 mW / cm ² . When the light irradiation intensity to the active energy ray-curable resin adhesive containing an epoxy resin is less than 0.1 mW / cm ² , the reaction time becomes too long, and when it exceeds 100 mW / cm ² , the lamp emits radiation. Heat and heat generated during polymerization of the composition may cause yellowing of the active energy ray-curable resin adhesive containing the epoxy resin and deterioration of the polarizing film. The light irradiation time to the active energy ray-curable resin adhesive containing an epoxy resin is controlled for each adhesive to be cured and is not particularly limited, but is expressed as a product of irradiation intensity and irradiation time. that the integrated light quantity is preferably set such that the 10~5000mJ / cm ^2. When the integrated light quantity to the active energy ray-curable resin adhesive containing the epoxy resin is less than 10 mJ / cm ² , the generation of active species derived from the initiator may not be sufficient, and curing may be insufficient. There, whereas the integrated quantity of light is more than 5000 mJ / cm ^2, the irradiation time is very long, and what disadvantageous for productivity improvement.

  The irradiation with active energy rays is preferably cured within a range in which various functions of the polarizing plate such as the degree of polarization, transmittance and hue of the polarizing film, and transparency of the protective film do not deteriorate.

  In addition, when an adhesive is used for bonding between the polarizing film and the protective film or the optical compensation film, as the adhesive, a conventionally known appropriate adhesive can be used without particular limitation, for example, an acrylic adhesive, Examples include urethane adhesives and silicone adhesives. Among these, an acrylic pressure-sensitive adhesive is preferably used from the viewpoints of transparency, adhesive strength, reliability, reworkability, and the like. The pressure-sensitive adhesive layer can be provided by a method in which such a pressure-sensitive adhesive is used, for example, in the form of an organic solvent solution, which is applied to a base film with a die coater or a gravure coater, and dried. Can be provided also by a method of transferring a sheet-like pressure-sensitive adhesive formed on a plastic film (referred to as a separate film) to the base film. Although there is no restriction | limiting in particular also about the thickness of an adhesive layer, Generally it is preferable to exist in the range of 2-40 micrometers.

  Such a polarizing plate of the present invention is preferably used as a back-side polarizing plate disposed between a liquid crystal cell and a backlight in a liquid crystal display device.

(Liquid crystal panel, liquid crystal display device)
The present invention is also a liquid crystal panel comprising a liquid crystal cell and the polarizing plate of the present invention laminated on the liquid crystal cell, wherein the polarizing plate is opposite to the side of the polarizing film on which the sheet member is laminated. The present invention also provides a liquid crystal panel that is arranged so that the side faces the liquid crystal cell. Further, the present invention is a liquid crystal display device including the backlight and the above-described liquid crystal panel of the present invention in this order, and the liquid crystal panel is a liquid crystal in which the sheet member is disposed so as to face the backlight. A display device is also provided. Here, FIG. 7 is a cross-sectional view schematically showing a liquid crystal display device 11 of a preferred example of the present invention. In the example shown in FIG. 7, the polarizing plate 1 of the present invention shown in FIG. 1 is disposed between the liquid crystal cell 13 and the backlight 12, and an adhesive layer 16 is provided on the opposite side of the liquid crystal cell 13 from the polarizing plate 1. In this example, the polarizing film 14 is fixed through the adhesive film 17 and the protective film 15 is fixed to the polarizing film 15 through the adhesive layer 17.

  Such a liquid crystal display device 11 of the present invention includes a liquid crystal panel in which the polarizing plate 1 of the present invention is bonded to the back surface of the liquid crystal cell 13, so that it has sufficient mechanical strength while corresponding to thinning. Furthermore, by arranging the sheet member 3 side having the prism-like or lens-like surface shape of the polarizing plate 1 of the present invention on the back side of the liquid crystal panel, adhesion between the liquid crystal panel and the backlight 12 can be prevented, Furthermore, a highly visible liquid crystal display device is provided.

  In the liquid crystal display device 11 of the present invention, for the portions other than the above-described features, an appropriate configuration of a conventionally known liquid crystal display device can be adopted, and the configuration requirements (light diffusion) that the liquid crystal display device normally includes other than the liquid crystal panel The plate, the light guide plate, etc.) are not particularly limited, but a light guide plate type backlight system including a sidelight is preferably used. Moreover, although a liquid crystal panel usually provides a polarizing plate also on the front side of the liquid crystal cell, the polarizing plate provided on the front side of the liquid crystal cell is not particularly limited, and any conventionally known appropriate polarizing plate can be used. Examples thereof include a polarizing plate subjected to an antiglare treatment, a hard coat treatment, and an antireflection treatment. Moreover, the polarizing plate by which the polyethylene terephthalate film, the acrylic film, and the polypropylene film were laminated | stacked on the single side | surface of the polarizing film may be sufficient. The “rear side” of the liquid crystal cell and liquid crystal panel described above means the backlight side when the liquid crystal panel is mounted on the liquid crystal display device, and the “front side” of the liquid crystal cell and liquid crystal panel means that the liquid crystal panel is liquid crystal It means the viewing side when mounted on a display device.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified.

(Production Example 1: Production of polarizing film)
A polyvinyl alcohol film having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% or more and a thickness of 75 μm was immersed in pure water at 30 ° C., and then the weight ratio of iodine / potassium iodide / water was 0.02 / 02. / 100 aqueous solution at 30 ° C. Then, it was immersed at 56.5 ° C. in an aqueous solution having a potassium iodide / boric acid / water weight ratio of 12/5/100. Subsequently, the film was washed with pure water at 8 ° C. and then dried at 65 ° C. to obtain a polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.

(Production Example 2: Production of UV-curable adhesive)
Hydrogenated epoxy resin (Epicoat YX8000, manufactured by Japan Epoxy Resins Co., Ltd .: diglycidyl ether of hydrogenated bisphenol A having an epoxy equivalent of about 205 g / equivalent) 10.0 g, photocationic polymerization initiator ( CI5102, Nippon Soda Co., Ltd.) 4.0 g and photosensitizer (CS7001, Nippon Soda Co., Ltd.) 1.0 g are weighed into a 100 ml disposable cup, mixed and defoamed, did.

(Production Example 3: Production of sheet member)
The following mixture as an ultraviolet curable resin composition was applied to a mold that was designed in advance so that the pitch of the prism-shaped surface shape after molding was 50 μm and the apex angle was 65 °, and the surface was smoothed. Thereafter, a polyethylene terephthalate film having a thickness of 188 μm was overlaid. Subsequently, 1000 mJ / cm < ² > of ultraviolet rays were irradiated with the integrated ultraviolet irradiation amount of 320-390 nm, and the ultraviolet curable resin composition was hardened. Then, it peeled from the metal mold | die and the sheet | seat member which has a triangular prism in the surface shape was obtained. All the sheet members had a shape as designed.

・ Fancryl FA-321M (manufactured by Hitachi Chemical Co., Ltd .: ethylene oxide modified bisphenol A methacrylate): 45 parts by weight
NK ester A-BPE-4 (manufactured by Shin-Nakamura Chemical Co., Ltd .: ethylene oxide modified bisphenol A diacrylate): 25 parts by weight
Sartomer 285 (Sartomer, Inc .: tetrahydrofurfuryl acrylate): 30 parts by weight Darocur 1173 (Merck Japan, 2-hydroxy-2-methyl-1-phenylpropan-1-one): 3 parts by weight
<Example 1>
(Preparation of polarizing plate)
On one surface of the polarizing film obtained in Production Example 1, a sheet member having the triangular prism obtained in Production Example 3 in a surface shape is provided, and on the other surface is a triacetyl cellulose film (80 μm, manufactured by Konica Minolta Opto). Bonding was performed via the ultraviolet curable adhesive obtained in Production Example 2. Next, it is passed once at a line speed of 1.0 m / min through an ultraviolet irradiation device (manufactured by Nippon Batteries Co., Ltd .: UV lamp uses HAL400NL at 80 W and the irradiation distance is 50 cm) and has a good appearance. A polarizing plate was obtained. The curability of the epoxy resin composition as an adhesive was good. Moreover, when the adhesiveness to a sheet | seat member was evaluated by the cross cut method described in JISK5400, the non-peeling cross cut number with respect to the number of the formed cross cuts was 100/100, and the favorable adhesiveness was shown. An acrylic pressure-sensitive adhesive layer having a thickness of 25 μm was provided on the outer surface of the triacetyl cellulose film of the polarizing plate. A polarizing plate is placed on the back of the liquid crystal cell via an adhesive layer, and a commercially available polarizing plate is placed on the front of the liquid crystal cell to assemble a liquid crystal panel. This is a commercially available light diffusion plate and light guide plate type backlight. In combination, a liquid crystal display device was produced. When the display of the liquid crystal display device was visually observed, a bright image was obtained when viewed from the front, and the visibility was good.

<Comparative Example 1>
A polarizing plate was prepared in the same manner as in Example 1 except that a water-based urethane adhesive was used instead of the epoxy resin adhesive. As a result, a large gap was generated between the polarizing film and the sheet member, and a polarizing plate having a good appearance could not be produced. Moreover, in the obtained laminated product, the sheet member could be easily peeled by hand and was not adhered to the polarizing film at all.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Polarizing plate, 2 Polarizing film, 3 Sheet member, 4 Active energy ray-curable resin adhesive layer, 5 Protective film, 6 Adhesive layer, 11 Liquid crystal display device, 12 Backlight, 13 Liquid crystal cell, 14 Polarizing film, 15 Protective film, 16 adhesive layer, 17 adhesive layer.

Claims (6)

A polarizing film comprising a uniaxially stretched polyvinyl alcohol-based resin film in which iodine or a dichroic dye is adsorbed and oriented;
A polarizing plate comprising: a sheet member having a prismatic or lens-like surface shape laminated on the polarizing film via an active energy ray-curable resin adhesive layer containing an epoxy resin.   The material of the sheet member is polyolefin resin, acrylic resin, polycarbonate resin, polyester resin, polystyrene resin, methyl methacrylate-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, and acrylonitrile-styrene. The polarizing plate according to claim 1, wherein the polarizing plate is a thermoplastic resin selected from the group consisting of a copolymer.   The polarizing plate according to claim 1 or 2, wherein an optical compensation film or a protective film is laminated on the side opposite to the side on which the sheet member of the polarizing film is laminated.   The polarizing plate according to claim 1, which is used as a back side polarizing plate disposed between a liquid crystal cell and a backlight in a liquid crystal display device. A liquid crystal panel comprising a liquid crystal cell and the polarizing plate according to any one of claims 1 to 4 laminated on the liquid crystal cell,
The said polarizing plate is a liquid crystal panel arrange | positioned so that the opposite side to the side by which the said sheet | seat member was laminated | stacked in a polarizing film may oppose a liquid crystal cell.   A liquid crystal display device comprising the backlight and the liquid crystal panel according to claim 5 in this order, wherein the liquid crystal panel is disposed so that the sheet member faces the backlight.

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