JP2014006447A - Deflection plate integrated optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deflection plate integrated optical laminate capable of being a thin film, at the same time, having a display screen of the image display device be flat, preventing occurrence of a curl by suppressing a dimension change due to temperature change and suppressing a change in hue, even when viewed with a pair of sunglasses having a deflection property.SOLUTION: A deflection plate integrated optical laminate 10 is arranged on a display screen side of an image display panel and the optical laminate is laminated on a deflection element film 11. In this case, the optical laminate includes a photo-transmissive base material 12 having birefringence in a screen and a bar code layer 14 provided on a shield layer 13. The phot-transmissive base material 12 has retardation of 3000nm or more and the photo-transmissive base material 12 on the optical laminate is provided on the deflection element film 11.

Description

The present invention relates to a polarizing plate integrated optical laminate in which a polarizing plate and an optical laminate are integrated.

In a liquid crystal display device (LCD), a pair of polarizing plates are usually arranged on the front and back of a liquid crystal cell. In an organic electroluminescence (EL) display device, a polarizing plate, particularly an elliptical or circular polarizing plate, is provided on the viewing side of the organic EL element. Is often installed to provide an anti-reflection function. These polarizing plates are provided with an optical laminate having functions such as antireflection and hard coat on the outermost surface.

In general, the image display panel is provided with a driver IC or the like for driving the image display panel on an outer peripheral portion that is off the display screen. In the image display device, a frame-like member called a bezel (metal cover) is provided on the outermost surface so as to surround the periphery of the display screen, and the driver IC is hidden from the display screen by the bezel (for example, (See Patent Documents 1 and 2).
By the way, in recent years, the flattening of the display screen has been promoted along with the thinning of the image display device. However, in the image display device having a configuration including such a bezel, the bezel protrudes from the display screen and is flat. Could not display screen.

Therefore, for example, a polarizing plate integrated optical laminate in which a frame for concealing a driver IC for driving the image display panel is formed by printing between the optical laminate and the polarizing element film is used as the display screen of the image display panel. A method of arranging the image display device on the side and flattening the display screen of the image display device has been considered.
Since the polarizing plate integrated optical laminate having such a configuration does not require a bezel for concealing the driver IC on the outermost surface, the display screen can be flattened.
However, in order to reduce the thickness of the image display device, it is essential to reduce the thickness of the polarizing plate-integrated optical laminate. The polarizing plate-integrated optical laminate having such a configuration includes a conventional polarizing film and an optical stack. During this period, it is necessary to form a layer including a frame for concealing the driver IC, so that the demand for thinning cannot be sufficiently met.

Conventionally, an optical laminate has a structure in which a hard coat layer is laminated on a light-transmitting substrate, and the light-transmitting substrate is made of a cellulose ester typified by triacetyl cellulose. A film has been used (for example, see Patent Document 3). This is because cellulose ester is excellent in transparency and optical isotropy, and has almost no phase difference in the plane (almost no birefringence in the plane), so that the vibration direction of incident linearly polarized light can be changed. Since there is little impact on the display quality of the image display device and it has moderate water permeability, moisture remaining in the polarizer when the optical laminate integrated polarizing plate is produced is passed through the optical laminate. This is based on the advantage that it can be dried.
However, the cellulose ester film is a disadvantageous material in terms of cost, and has insufficient moisture resistance and heat resistance. When the optical laminate is used as a polarizing plate protective film in a hot and humid environment, the cellulose ester film As the image display device is an LCD, for example, when the image display device is an LCD, the entire liquid crystal cell is curled and the display quality is lowered. An example of curling the entire liquid crystal cell and lowering the display quality is, for example, that the liquid crystal cell curls and adheres to the backlight member, thereby causing partial moire or unevenness. Such a problem is that the glass plate of a liquid crystal cell has conventionally been 0.5 to 1 mm thick in the thinning of LCDs for notebook personal computers, LCDs for mobile terminals, LCDs for mobile phones, etc. This is because the adoption of glass plates with a thickness of less than 0.5 mm is progressing.
In addition, when the image display device is an organic EL display device, the circularly polarizing plate installed for the purpose of preventing reflection of external light is installed only on the viewing side of the organic EL element, so this curl problem is more remarkable. It becomes.

For such problems, for example, it is known that a dimensional change with respect to humidity can be reduced by using a cyclic olefin polymer (COP) film having excellent moisture resistance and heat resistance as a protective layer of a polarizer. Yes. In addition, by using a λ / 4 retardation film using a cycloolefin polymer as a protective layer on the observer side of the polarizer, the polarized light on the output side becomes circularly polarized light. There has been proposed a technique capable of solving the problem that the image becomes invisible (see, for example, Patent Document 4).
However, when a circularly polarizing plate using such a COP film as a protective layer for a polarizer is used in an image display device, the image display device is viewed in the outer peripheral direction of the display screen while being viewed with sunglasses having polarization characteristics. In the case of rotating the image, the display image has a problem that a color change occurs.

JP 2005-215185 A JP 2010-271629 A JP 2003-149438 A JP 2011-1113018 A

In view of the above-mentioned present situation, the present invention can be made thin, and the display screen of the image display device can be made flat. An object of the present invention is to provide a polarizing plate-integrated optical laminate in which a change in tint is suppressed even when viewed with sunglasses having polarization characteristics.

The present invention is a polarizing plate-integrated optical laminate that is disposed on the display screen side of an image display panel and in which an optical laminate is laminated on a polarizing element film, and the optical laminate has an in-plane birefringence index. A light-transmitting substrate, a shielding layer formed along the outer periphery of the light-transmitting substrate on the side opposite to the polarizing element film, and the light-transmitting substrate and the shielding layer. A polarizing plate characterized in that the light-transmitting substrate has a retardation of 3000 nm or more, and the light-transmitting substrate of the optical laminate is provided on the polarizing element film. This is a plate-integrated optical laminate.

In the polarizing plate-integrated optical laminate of the present invention, the light-transmitting substrate having a birefringence in the plane is a slow axis direction that is the direction in which the refractive index is the largest in the plane of the light-transmitting substrate. And the angle between the polarizing element film and the absorption axis direction is preferably laminated so as to be in the range of 45 ° ± 15 °.
The shielding layer is preferably formed in a region that hides the driver IC that drives the image display panel when observed from the display screen side.
The shielding layer preferably has a thickness of 2.0 to 5.0 μm and a transmission density of 3.0 to 5.6.
The present invention is also an image display device comprising the polarizing plate integrated optical laminate of the present invention.
The present invention is described in detail below.
In the present invention, unless otherwise specified, curable resin precursors such as monomers, oligomers, and prepolymers are referred to as “resins”.

As a result of intensive studies on the conventional polarizing plate-integrated optical laminate, the present inventors have found that a shielding layer for concealing the driver IC for controlling the image display panel from the display screen is included in the optical laminate, specifically, light transmission. By providing between the conductive substrate and the hard coat layer provided on the light transmissive substrate, it can be hidden from the display screen of the driver IC without increasing the film thickness of the optical laminate, As a result, it has been found that thinning and flattening of the display screen can be suitably achieved, and the present invention has been completed.

FIG. 1 is a cross-sectional view schematically showing an example of a polarizing plate integrated optical laminate of the present invention.
As shown in FIG. 1, in the polarizing plate integrated optical laminate 10 of the present invention, an optical laminate having a light-transmitting substrate 12 and a hard coat layer 14 is laminated on a polarizing element film 11.
The optical layered body is formed with a shielding layer 13 formed along the outer periphery on the side surface opposite to the polarizing element film 11 of the light transmissive substrate 12, and the hard coat layer 14 includes the light transmissive substrate 12 and It is provided on the shielding layer 13.

Here, the conventional polarizing element film has a configuration in which a protective substrate such as a triacetyl cellulose substrate is attached on the polarizing element. In the conventional polarizing plate-integrated optical laminate, the polarizing element film is protected. An optical laminate was disposed on the substrate. On the other hand, in the polarizing plate integrated optical laminate of the present invention, the optical laminate is disposed directly on the polarizing element. That is, in the polarizing plate-integrated optical laminate of the present invention, the light transmissive substrate of the optical laminate also serves as a protective film for the polarizing element of the polarizing element film. With such a configuration, the polarizing plate-integrated optical laminate of the present invention can be reduced in thickness by omitting the protective film for the polarizing element film in the conventional polarizing plate-integrated optical laminate.

Examples of the polarizing element film include a polyvinyl alcohol polarizing element.
The polyvinyl alcohol polarizing element is a polarizing element in which iodine or a dichroic dye is adsorbed on a polyvinyl alcohol film.
The polyvinyl alcohol film is not particularly limited, and a commonly used polyvinyl alcohol film can be used. For example, what extended | stretched uniaxially the polyvinyl alcohol film, the polyvinyl formal film, the polyvinyl acetal film, the poly (ethylene-vinyl acetate) copolymer film, etc. are mentioned.
The thickness of the polyvinyl alcohol film is also not particularly limited, and for example, a thickness of about 5 to 150 μm is used.
In the polarizing plate-integrated optical laminate of the present invention, an optical laminate described later is directly attached to the polarizing element film.

In the polarizing plate-integrated optical laminate of the present invention, the shielding layer is formed along the outer periphery on the side surface opposite to the polarizing element film of the light transmissive substrate. Shape.
Such a shielding layer is a member that serves to conceal the driver IC of the image display panel from the display screen, and is formed in a region that conceals the driver IC that drives the image display panel when observed from the display screen side. It is preferable.
The width of the shielding layer from the outer peripheral portion of the polarizing plate-integrated optical laminate (lateral width in the shielding layer 13 shown in FIG. 1) is appropriately determined depending on the size of the driver IC to be shielded. It is preferable that it is 0-5.0 micrometers. If it is less than 2.0 μm, a black density sufficient to sufficiently shield the driver IC may not be obtained. If it exceeds 5.0 μm, the step difference from the light-transmitting substrate becomes large, and the hard coat layer Air bubble biting is likely to occur between the two. Further, it is not preferable because of the demand for thinning. The minimum with more preferable thickness of the said shielding layer is 3.0 micrometers, and a more preferable upper limit is 4.5 micrometers.

The shielding layer preferably has a transmission density of 3.0 to 5.6. If it is less than 3.0, the driver IC may not be sufficiently shielded, and if it exceeds 5.6, the shielding layer thickness needs to be excessively increased, which is not preferable. A more preferable lower limit of the transmission density is 3.3, and a more preferable upper limit is 5.5. In addition, the said transmission density means the optical density measured as a ratio of the transmitted light with respect to the incident light intended for the film etc. based on ISO5-2 (2009).

The shielding layer can be formed using a shielding layer composition in which a light-shielding pigment is dispersed in a binder resin component.
The light-shielding pigment is not particularly limited, but organic black pigments such as carbon black, aniline black, and perylene black, inorganic black pigments containing copper, iron, chromium, manganese, cobalt, titanium, etc., aluminum and mica Examples thereof include black dyes mixed with a scaly shielding material such as carbon black, and among these, carbon black is preferably used.

The content of the light-shielding pigment is appropriately determined according to the transmission density of the target shielding layer, but is preferably 10 to 70 with respect to 100 parts by mass of the solid content of the shielding layer composition. Part by mass. When the amount is less than 10 parts by mass, a shielding layer having a sufficient transmission density may not be formed. When the amount exceeds 70 parts by mass, the strength of the shielding layer to be formed may be insufficient. A more preferred lower limit is 20 parts by mass, and a more preferred upper limit is 50 parts by mass.

The binder resin is not particularly limited as long as it can carry the light-shielding pigment. For example, cellulose-based celluloses such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and butyric acid cellulose Resins; Vinyl resins such as polyvinyl chloride, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal, and polyvinylpyrrolidone; Acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide; Polyurethane resins; Polyamide resins Resins; Polyester resins and the like, and copolymer resins and modified resins thereof can be used.
The binder resin may be a solvent drying resin, a two-component reaction resin, or an energy beam curable resin.

The shielding layer composition is obtained by dissolving or dispersing a light-shielding pigment such as carbon black and a binder resin in a suitable organic solvent or water together with conventionally known additives to be added as necessary. be able to.
Examples of the organic solvent include toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethanol, isopropyl alcohol, cyclohexanone, dimethylformamide, and the like.

As a method of forming the shielding layer using the shielding layer composition, for example, the shielding layer is formed on the light-transmitting substrate by a known method such as a gravure printing method, a screen printing method, or a gravure offset printing method. It can be formed by applying the composition and performing drying, heating, energy ray irradiation, or the like.

The hard coat layer is provided on the light transmissive substrate and the shielding layer.
The hard coat layer is formed using a hard coat layer forming composition containing a binder resin and a solvent.
In the hard coat layer composition, examples of the binder resin include an ionizing radiation curable resin, an ionizing radiation curable resin, and a solvent-drying resin (a solid content at the time of coating) that is a resin curable by ultraviolet rays or electron beams. A resin or a thermosetting resin can be used, for example, by simply drying the solvent added for adjustment. Among these, it is preferable to contain an ionizing radiation curable resin.

Examples of the ionizing radiation curable resin include compounds having one or more unsaturated bonds such as a compound having an acrylate functional group. Examples of the compound having one unsaturated bond include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone and the like. Examples of the compound having two or more unsaturated bonds include polymethylolpropane tri (meth) acrylate, hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and pentaerythritol tris. (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, isocyanuric acid modified tri (meta ) A polyfunctional compound such as acrylate and a reaction product such as (meth) acrylate (for example, poly (meth) acrylate ester of polyhydric alcohol).
In the present specification, (meth) acrylate means acrylate or methacrylate.

In addition to the above compounds, the above-mentioned ionizing radiation curing is also applicable to relatively low molecular weight polyester resins having unsaturated double bonds, polyether resins, acrylic resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. It can be used as a mold resin.

When using an ionizing radiation curable resin as an ultraviolet curable resin, it is preferable to use a photopolymerization initiator. Specific examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amino oxime esters, thioxanthones, propiophenones, benzyls, benzoins, and acylphosphine oxides. Further, it is preferable to use a mixture of photosensitizers, and specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine and the like.

As the photopolymerization initiator, in the case of a resin system having a radical polymerizable unsaturated group, it is preferable to use acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether or the like alone or in combination. In the case of a resin system having a cationic polymerizable functional group, an aromatic diazonium salt, an aromatic sulfonium salt, an aromatic iodonium salt, a metallocene compound, a benzoin sulfonic acid ester or the like is used alone or as a mixture as a photopolymerization initiator. It is preferable. The addition amount of the photopolymerization initiator is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the ionizing radiation curable composition.

The solvent-drying resin used by mixing with the ionizing radiation curable resin mainly includes a thermoplastic resin.
As the thermoplastic resin, those generally exemplified are used. By adding the solvent-drying resin, coating film defects on the coated surface can be effectively prevented. As a specific example of a preferable thermoplastic resin, as the thermoplastic resin, those generally exemplified are used.
By adding the solvent-drying resin, coating film defects on the coated surface can be effectively prevented.
Specific examples of preferable thermoplastic resins include, for example, styrene resins, (meth) acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, and polyester resins. , Polyamide resins, cellulose derivatives, silicone resins, rubbers or elastomers.
As the thermoplastic resin, it is usually preferable to use a resin that is non-crystalline and soluble in an organic solvent (particularly a common solvent capable of dissolving a plurality of polymers and curable compounds). In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferred.

Examples of the thermosetting resin that can be used as the resin include phenol resin, urea resin, diallyl phthalate resin, melanin resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, aminoalkyd resin, melamine-urea cocondensation resin, Examples thereof include silicon resins and polysiloxane resins. When a thermosetting resin is used, a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, and the like can be used in combination as necessary.

As the binder resin, urethane (meth) acrylate is also preferably used. Specific examples of the urethane (meth) acrylate include a purple light series manufactured by Nippon Synthetic Chemical Industry, such as UV1700B, UV6300B, UV7605B, UV7640B, UV7600B, etc .; an art resin series manufactured by Negami Kogyo, for example, art resin UN9000H, Art Resin UN3320HA, Art Resin UN3320HB, Art Resin UN3320HC, Art Resin UN3320HS, Art Resin UN901M, Art Resin UN902MS, Art Resin UN903, Art Resin UN904, etc .; UA100H, H4H15 made by Shin-Nakamura Chemical Co., Ltd. U4HA, U6HA, UA32P, U6LPA, U324A, U9HAMI, etc .; Ebecryl series manufactured by Daicel-Cytec, for example Ebecryl 1290, 5129, 254, 264, 265, 1259, 1264, 4866, 9260, 8210, 204, 205, 6602, 220, 4450 and the like; Beam set 577 made by Arakawa Chemical Industries, Ltd .; DPHA 40H made by Nippon Kayaku Co., Ltd. UX5000, UX5001T; CN9006, CN968 manufactured by Thermar Company, etc. Among these, UV1700B, UV7600B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), DPHA40H (manufactured by Nippon Kayaku Co., Ltd.), Art Resin UN904, Art Resin UN3320HS (manufactured by Negami Kogyo Co., Ltd.), Beam Set 577 (manufactured by Arakawa Chemical Industries, Ltd.) U15HA (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like.

The composition for forming a hard coat layer is obtained by dissolving or dispersing the above-described binder resin and, if necessary, a photopolymerization initiator, a low refractive index agent described below and known additives in a solvent. Can do. The said hard-coat layer can be obtained by forming the coating film by the said composition for hard-coat layer formation on the said transparent base material and the said shielding layer, and hardening the said coating film.

The solvent can be selected and used according to the type and solubility of the binder resin, and at least solids (a plurality of polymers and curable resin precursors, reaction initiators, other additives) can be uniformly dissolved. Any solvent may be used. Examples of such solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons ( Cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (ethanol, isopropanol, butanol, Cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethylsulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc., and mixtures thereof It may be a medium.

The hard coat layer composition preferably contains hollow silica fine particles as a low refractive index agent. By containing the low refractive index agent, the refractive index of the hard coat layer formed can be made lower than the layer provided immediately below, and light reflection can be prevented.
When the low refractive index agent is contained, the refractive index is less than the refractive index of the layer immediately below, but the refractive index difference with the layer immediately below is preferably 0.02 to 0.3, more Preferably it is 0.05-0.2.
Further, the refractive index itself of the hard coat layer at this time is preferably 1.45 or less in view of obtaining sufficient antireflection properties, more preferably 1.40 or less, and further preferably 1.38 or less.

The hollow silica fine particles are, for example, silica fine particles having an outer shell and porous or hollow inside, and are disclosed in JP-A-6-330606, JP-A-7-013137, It can be obtained by various production methods described in JP-A No. 7-133105 and JP-A No. 2001-233611.
It does not specifically limit as content of the said hollow silica particle, It adjusts suitably so that the refractive index of the hard-coat layer to form may become the said range.

Although it does not specifically limit as a content rate (solid content) of the raw material in the said composition for hard-coat layer formation, Usually, it is preferable to set it as 5-70 mass%, especially 25-60 mass%.
The hard coat layer-forming composition includes a resin, a dispersant, an interface depending on purposes such as increasing the hardness of the hard coat layer, suppressing cure shrinkage, controlling the refractive index, and imparting antiglare properties. Activators, known antistatic agents, silane coupling agents, thickeners, anti-coloring agents, coloring agents (pigments, dyes), antifoaming agents, leveling agents, flame retardants, UV absorbers, adhesion-imparting agents, polymerization prohibition Additives such as agents, antioxidants, surface modifiers, and lubricants may be added.

The method for preparing the composition for forming a hard coat layer is not particularly limited as long as each component can be uniformly mixed. For example, the composition can be performed using a known apparatus such as a paint shaker, a bead mill, a kneader, or a mixer.

Specifically, in the step of forming the hard coat layer, the hard coat layer-forming composition is applied onto a light-transmitting substrate and a shielding layer to form a coat, and the resulting coat is cured. Is done by doing.
The coating method is not particularly limited. For example, spin coating method, dip method, spray method, die coating method, bar coating method, roll coater method, meniscus coater method, flexographic printing method, screen printing method, pea coater method, etc. Can be mentioned.

Although it does not specifically limit as hardening of the said coating film, It is preferable to form by drying as needed and making it harden | cure by heating, active energy ray irradiation, etc.

Examples of the active energy ray irradiation include irradiation with ultraviolet rays or electron beams. Specific examples of the ultraviolet light source include light sources such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light fluorescent lamp, and a metal halide lamp. Moreover, as a wavelength of an ultraviolet-ray, the wavelength range of 190-380 nm can be used. Specific examples of the electron beam source include various electron beam accelerators such as a cockcroft-wald type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type.

In the optical layered body of the present invention, the hard coat layer preferably has a film thickness (at the time of curing) of 3.0 to 20 μm. When it is less than 3.0 μm, the pencil hardness becomes less than H, and the hard coat property may be insufficient. When it exceeds 20 μm, the flexibility of the film is insufficient, and cracks are likely to occur during the process. The more preferable lower limit of the film thickness (at the time of curing) of the hard coat layer is 5 μm, and the more preferable upper limit is 15 μm.
The film thickness of the hard coat layer is a value measured by observing a cross section of the hard coat layer formed on the light-transmitting substrate with an electron microscope (SEM, TEM, STEM).

In the optical layered body of the present invention, a protective layer may be provided between the above-described shielding layer and hard coat layer.
The said protective layer is a layer which plays the role which protects the said shielding layer from the solvent used for the said composition for hard-coat layer formation, and should just be formed so that the whole surface of the said shielding layer may be covered.
The resin constituting such a protective layer is preferably made of a material that suppresses penetration of a solvent used in the hard coat layer composition, particularly a penetrating solvent described later into the shielding layer. Examples of such a resin include two-component reactive inks such as urethane and epoxy.

The optical layered body of the present invention has a light-transmitting substrate having a birefringence in the plane.
The light-transmitting substrate having a birefringence in the plane is not particularly limited as long as it satisfies the dimensional change with respect to the humidity. For example, a substrate made of polycarbonate, cycloolefin polymer, acrylic, polyester, or the like is used. Can be mentioned. Among them, a polyester base material that is advantageous in cost and mechanical strength is preferable. In the following description, a light-transmitting substrate having a birefringence in the plane will be described as a polyester substrate.

The polyester base material has a retardation of 3000 nm or more. When it is less than 3000 nm, the display image of the image display device using the polarizing plate-integrated optical laminate of the present invention is viewed while wearing sunglasses having polarization characteristics, and the image display device is displayed on the outer periphery of the display screen. When rotated in the direction, a color difference occurs in the display image. On the other hand, the upper limit of the retardation of the polyester base material is not particularly limited, but is preferably about 30,000 nm. If it exceeds 30,000 nm, the film thickness becomes considerably large, which is not preferable.
It is preferable that the retardation of the said polyester base material is 5000-25000 nm from a viewpoint of thin film formation. A more preferable range is 7000 to 20,000 nm.

The retardation is the refractive index (nx) in the direction having the highest refractive index (slow axis direction) in the plane of the polyester substrate, and the refraction in the direction orthogonal to the slow axis direction (fast axis direction). It is represented by the following formula by the rate (ny) and the thickness (d) of the polyester base material.
Retardation (Re) = (nx−ny) × d
The retardation can be measured, for example, by KOBRA-WR manufactured by Oji Scientific Instruments (measurement angle 0 °, measurement wavelength 589.3 nm).
Further, using two polarizing plates, the orientation axis direction (principal axis direction) of the polyester substrate is obtained, and the refractive indexes (nx, ny) of two axes orthogonal to the orientation axis direction are Abbe's refractive indices. It calculates | requires by the total (NAGO-4T by the Atago company). Here, an axis showing a larger refractive index is defined as a slow axis. The thickness d (nm) of the polyester substrate is measured using an electric micrometer (manufactured by Anritsu), and the unit is converted to nm. Retardation can also be calculated from the product of the refractive index difference (nx−ny) and the thickness d (nm) of the film.
In addition, a refractive index can also be measured using an Abbe refractometer and an ellipsometer, and the said shielding layer on the said polyester base material using a spectrophotometer (Shimadzu Corporation UV-3100PC). When an optical laminate is provided by providing a hard coat layer, the average reflectance (R) at a wavelength of 380 to 780 nm of the hard coat layer is measured, and the following formula is used from the obtained average reflectance (R): The value of the refractive index (n) may be obtained.
The average reflectance (R) of the hard coat layer was obtained by coating each raw material composition on 50 μm PET without easy adhesion treatment to obtain a cured film having a thickness of 1 to 3 μm, and the surface on which PET was not applied (back surface) In order to prevent back surface reflection, the average reflectance of each cured film was measured after applying a black vinyl tape (for example, Yamato vinyl tape No 200-38-21 38 mm width) having a width larger than the measurement spot area. The refractive index of the polyester base material was measured after black vinyl tape was similarly applied to the surface opposite to the measurement surface.
R (%) = (1-n) ² / (1 + n) ²
Further, as a method for measuring the refractive index of the hard coat layer after becoming an optical layered product, the hard coat film is scraped off with a cutter or the like to prepare a powder sample, and JIS K7142 (2008) B method (powder or The Becke method (for a granular transparent material) (using a Cargill reagent with a known refractive index, the powder sample is placed on a glass slide, the reagent is dropped on the sample, and the sample is immersed in the reagent. Observe the state by microscopic observation, and use the bright line generated in the sample outline due to the difference in the refractive index of the sample and the reagent; the method using the refractive index of the reagent that makes the Becke line invisible visually observable. Can do.
In the case of a polyester base material, the refractive index varies depending on the direction. Therefore, the average reflectance can be measured and determined by applying the black vinyl tape to the treated surface of the hard coat layer instead of the Becke method.

In the present invention, the nx-ny (hereinafter also referred to as Δn) is preferably 0.05 or more. If Δn is less than 0.05, the film thickness necessary for obtaining the retardation value described above may be increased. On the other hand, the Δn is preferably 0.25 or less. If it exceeds 0.25, it becomes necessary to stretch the polyester base material excessively, so that the polyester base material is likely to be torn and torn, and the practicality as an industrial material may be significantly reduced.
From the above viewpoint, the more preferable lower limit of Δn is 0.07, and the more preferable upper limit is 0.15. In addition, when said (DELTA) n exceeds 0.15, the durability of the polyester base material in a heat-and-moisture resistance test may be inferior. Since the durability in the heat and humidity resistance test is excellent, the more preferable upper limit of Δn is 0.12.
In addition, as said (nx), it is preferable that it is 1.66-1.78, a more preferable minimum is 1.68, and a more preferable upper limit is 1.73. Moreover, as said (ny), it is preferable that it is 1.55-1.65, a more preferable minimum is 1.57 and a more preferable upper limit is 1.62.
When nx and ny are in the above-described range and satisfy the above-described relationship of Δn, it is possible to improve suitable antireflection performance and bright place contrast.

The material constituting the polyester base material is not particularly limited as long as it satisfies the retardation described above, but is synthesized from an aromatic dibasic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof. Examples include linear saturated polyester. Specific examples of such polyester include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), and polyethylene-2,6-naphthalate.
The polyester used for the polyester substrate may be a copolymer of these polyesters. The polyester is mainly used (for example, a component of 80 mol% or more), and a small proportion (for example, 20 mol% or less). It may be blended with these types of resins. Polyethylene terephthalate or polyethylene-2,6-naphthalate is particularly preferable as the polyester because it has a good balance between mechanical properties and optical properties. In particular, it is preferably made of polyethylene terephthalate (PET). This is because polyethylene terephthalate is highly versatile and easily available. In the present invention, a polarizing plate integrated optical laminate capable of producing an image display device with high display quality can be obtained even with a highly versatile film such as PET. Furthermore, PET is excellent in transparency, heat or mechanical properties, can control the retardation by stretching, has a large intrinsic birefringence, and can obtain a large retardation relatively easily even when the film thickness is small.

The method for obtaining the polyester base material is not particularly limited as long as the above-described retardation is satisfied. For example, the polyester, such as PET, as a material is melted and extruded into a sheet to form glass. The method of heat-processing after transverse stretching using a tenter etc. at the temperature more than transition temperature is mentioned.
The transverse stretching temperature is preferably 80 to 130 ° C, more preferably 90 to 120 ° C. Further, the transverse draw ratio is preferably 2.5 to 6.0 times, more preferably 3.0 to 5.5 times. When the transverse draw ratio exceeds 6.0 times, the transparency of the resulting polyester base material tends to be lowered, and when the transverse draw ratio is less than 2.5 times, the draw tension becomes small. In some cases, the birefringence of the substrate becomes small, and the retardation cannot be increased to 3000 nm or more.
In the present invention, the unstretched polyester is subjected to transverse stretching under the above conditions using a biaxial stretching test apparatus, and then stretched in the flow direction with respect to the transverse stretching (hereinafter also referred to as longitudinal stretching). Also good. In this case, the longitudinal stretching preferably has a stretching ratio of 2 times or less. When the draw ratio of the above-mentioned longitudinal stretching exceeds twice, the value of Δn may not be within the preferred range described above.
The treatment temperature during the heat treatment is preferably 100 to 250 ° C, more preferably 180 to 245 ° C.

Examples of the method for controlling the retardation of the polyester substrate produced by the above-described method to 3000 nm or more include a method of appropriately setting the draw ratio, the drawing temperature, and the film thickness of the produced polyester substrate. Specifically, for example, the higher the stretching ratio, the lower the stretching temperature, and the thicker the film, the easier it is to obtain high retardation. The lower the stretching ratio, the higher the stretching temperature, and the film thickness. The thinner, the easier it is to obtain low retardation.

The thickness of the polyester substrate is preferably in the range of 10 to 400 μm. When the thickness is less than 10 μm, the retardation of the polyester base material cannot be increased to 3000 nm or more, the anisotropy of mechanical properties becomes remarkable, and tearing, tearing, and the like are likely to occur, and the practicality as an industrial material is significantly reduced. Sometimes. On the other hand, if it exceeds 400 μm, the polyester base material is very rigid, the flexibility specific to the polymer film is lowered, and the practicality as an industrial material is also lowered, which is not preferable. The minimum with more preferable thickness of the said polyester base material is 50 micrometers, a more preferable upper limit is 300 micrometers, and a still more preferable upper limit is 200 micrometers.

The polyester base material preferably has a transmittance in the visible light region of 80% or more, more preferably 84% or more. In addition, the said transmittance | permeability can be measured by JISK7361-1 (The test method of the total light transmittance of a plastic-transparent material).

In the present invention, the polyester substrate may be subjected to surface treatment such as saponification treatment, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, and flame treatment without departing from the spirit of the present invention. Good.

なお、上記式において、「３０℃９０％ＲＨ環境下での寸法」及び「３０℃０％ＲＨ環境下での寸法」とは、上記ポリエステル基材を、それぞれ３０℃９０％ＲＨ環境下及び３０℃０％ＲＨ環境下で保持したときの、遅相軸方向と該遅相軸方向に直交する方向との所定の２点間の長さの平均値である。 The polyester base material preferably has a dimensional change rate with respect to humidity of 0.6% or less. If it exceeds 0.6%, when the polarizing plate-integrated optical laminate of the present invention is used in an image display device, the dimensional change of the polyester substrate due to a change in humidity increases, curling occurs, and the display quality is lowered. Sometimes. A more preferable upper limit of the dimensional change rate is 0.3%, and a more preferable upper limit is 0.1%.
In the present specification, the dimensional change rate is the dimensional change rate when the polyester base material is held at 30 ° C. and 0% RH and then changed to 30 ° C. and 90% RH. And is calculated by the following equation.

In the above formula, “dimension under 30 ° C. and 90% RH environment” and “dimension under 30 ° C. and 0% RH environment” mean that the polyester base material is 30 ° C. and 90% RH environment and 30 respectively. It is the average value of the length between two predetermined points in the slow axis direction and the direction perpendicular to the slow axis direction when held in a 0% RH environment.

In the polarizing plate-integrated optical laminate of the present invention, the polyester base is formed by a slow axis direction that is the direction having the largest refractive index in the plane of the polyester base and the absorption axis of the polarizing element film. The layers are laminated so that the angle is preferably in the range of 45 ° ± 15 °, more preferably in the range of 45 ° ± 5 °. The angle formed between the slow axis direction of the polyester substrate and the absorption axis of the polarizing element film is the same as that when the polarizing plate-integrated optical laminate of the present invention is observed from the display screen side. The angle formed by the phase axis and the absorption axis.
Since the polyester base material is laminated so that the slow axis direction and the absorption axis direction are within the above range, the polarizing plate-integrated optical laminate of the present invention is used even when wearing sunglasses. This is because the visibility of the display screen of an image display device such as an LCD can be improved. The reason is that when the slow axis of the polyester base material is set at an angle θ with respect to the absorption axes of the two polarizing plates placed in a crossed Nicol state, the light transmittance (I / I ₀ ) Is represented by the following formula, because the transmittance is sufficiently increased within the above range.
I / I ₀ = sin ² 2θ · sin ² (πRe / λ)
In the above formula, I indicates the intensity of light transmitted through the two polarizing plates placed in the crossed Nicols state, and I ₀ is the light incident on the two polarizing plates placed in the crossed Nicols state. , Re represents retardation of the polyester substrate, and λ represents wavelength.

The optical layered body may also include other layers (an antistatic layer, an antiglare layer, a low refractive index layer, an antifouling layer, an adhesive layer, etc. 1 layer or two or more layers can be appropriately formed. Among these, it is preferable to have at least one of an antistatic layer, an antiglare layer, a low refractive index layer, and an antifouling layer. As these layers, the same layers as known optical laminates can be adopted.

The optical layered body preferably has a total light transmittance of 90% or more. If it is less than 90%, the color reproducibility and visibility may be impaired when the polarizing plate-integrated optical laminate of the present invention is mounted on the surface of the image display device. The total light transmittance is more preferably 95% or more, and still more preferably 98% or more.

The optical layered body preferably has a haze of less than 1%, more preferably less than 0.5%. Moreover, when anti-glare property is imparted to the optical laminate as in the case where a known anti-glare layer is formed, the haze is preferably less than 80%. The antiglare layer may be composed of a haze due to internal diffusion and a haze due to an uneven shape on the outermost surface, and the haze due to internal diffusion is preferably 3.0% or more and less than 79%, preferably 10% or more and less than 50%. It is more preferable that The haze on the outermost surface is preferably 1% or more and less than 35%, more preferably 1% or more and less than 20%, still more preferably 1% or more and less than 10%.

The optical layered body is preferably 2H or more, more preferably 3H or more, in a pencil hardness test (load 4.9 N) according to JIS K5600-5-4 (1999). Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

The polarizing plate-integrated optical laminate of the present invention comprising the optical laminate having the above-described structure is formed by forming the above-described shielding layer on the light-transmitting substrate, and further on the light-transmitting substrate and the shielding layer. After the hard coat layer is formed, the light transmissive substrate of the optical laminate and the polarizing element film can be attached by using a known water glue or the like. The manufacturing method of each member which comprises the said optical laminated body is as having mentioned above.

Since the polarizing plate-integrated optical laminate of the present invention is provided with a shielding layer at a predetermined position for concealing the driver IC of the image display panel from the display screen side, it can be reduced in thickness suitably. Since it is not necessary to provide a bezel as in the conventional image display device, the image display surface can be flattened.
The driver IC of the image display panel is not particularly limited, and examples include those used in conventionally known image display panels.

The polarizing plate integrated optical laminate of the present invention is disposed on the surface of an image display device.
As said image display apparatus, image display apparatuses, such as LCD, PDP, FED, ELD (organic EL, inorganic EL), CRT, tablet PC, a touch panel, electronic paper, etc., may be sufficient, for example.
An image display device comprising such a polarizing plate integrated optical laminate of the present invention is also one aspect of the present invention.

The LCD, which is a typical example, includes a transmissive image display panel and a light source device that irradiates the transmissive image display panel from the back. When the image display device is an LCD, the polarizing plate-integrated optical laminate of the present invention is formed on the surface of the transmissive image display panel.

When the present invention is a liquid crystal display device having the polarizing plate-integrated optical laminate, the light source of the light source device is irradiated from the lower side of the polarizing plate-integrated optical laminate. In the liquid crystal display device, a retardation plate may be inserted between the liquid crystal display element and the polarizing plate. An adhesive layer may be provided between the layers of the liquid crystal display device as necessary.

The PDP includes a front glass substrate (electrodes are formed on the surface) and a rear glass substrate disposed with a discharge gas sealed between and facing the front glass substrate. Examples of the back glass substrate include a glass substrate in which electrodes and minute grooves are formed on the surface, and red, green, and blue phosphor layers are formed in the grooves. When the image display device of the present invention is a PDP, the above-mentioned polarizing plate-integrated optical laminate is also provided on the surface of the surface glass substrate or on the front plate (glass substrate or film substrate). In the PDP, reflection of external light can be prevented by laminating a λ / 4 plate on the polarizing element surface opposite to the optical laminated body of the polarizing plate integrated optical laminated body.

The image display device is an ELD device that displays a light by providing a light emitter such as zinc sulfide or a diamine substance on a glass substrate or the like that emits light when a voltage is applied, or an electric signal to light. It may be an image display device such as a CRT that converts and generates an image visible to the human eye. In this case, the polarizing plate integrated optical laminate is provided on the outermost surface of each display device as described above or the surface of the front plate. In ELD, reflection of external light can be prevented by laminating a λ / 4 plate on the surface of the polarizing element opposite to the optical laminated body of the polarizing plate integrated optical laminated body.

In any case, the image display device of the present invention can be used for display display of a television, a computer, electronic paper, a touch panel, a tablet PC, or the like. In particular, it can be suitably used for the surface of high-definition image displays such as CRT, liquid crystal panel, PDP, ELD, FED, touch panel and the like.

Since the present invention has the above-described configuration, it can be thinned and the display screen of the image display device can be flat, and the occurrence of curling can be suppressed by suppressing the dimensional change with respect to the humidity change. Even when it is visually recognized with sunglasses having polarization characteristics, the color change is suppressed.
Therefore, the polarizing plate integrated optical laminate of the present invention includes a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED), an electronic It can be suitably applied to paper or the like.

It is sectional drawing which shows typically an example of the polarizing plate integrated optical laminated body of this invention.

The contents of the present invention will be described with reference to the following examples, but the contents of the present invention should not be construed as being limited to these embodiments. Unless otherwise specified, “part” and “%” are based on mass.

得られた光透過性基材の一方の面に、ウレタン樹脂にカーボンブラック顔料、溶剤、添加剤等を混練してなる遮蔽層用組成物（黒色インキ）（製品名：ＳＳ８０５墨、大日精化工業社製）を用い、グラビア印刷法により幅１２ｍｍの枠状の遮蔽層を光透過性基材の外周に沿って設けた。なお、黒色インキには、光透過性基材との密着性強化のため、イソシアネート系硬化剤（製品名：ラミックＢハードナー、大日精化工業社製）を５部添加した。また、遮蔽層は、蛍光灯が透過して見えないように同じ版で黒色インキを３度重ね印刷して充分隠蔽性のある遮蔽層（厚み３．５μｍ）とした。
遮蔽層の厚みは、デジマチックインジケーターＩＤ−Ｈ０５３０（Ｍｉｔｕｔｏｙｏ社製）を用いて、遮蔽層印刷層上を縦横方向にそれぞれ１００ｍｍ間隔で３点測定し、その平均値を印刷厚みとした。
また、遮蔽層について透過濃度を測定した。透過濃度は、透過濃度計３６１Ｔ（Ｘ−Ｒｉｔｅ社製）を用い、上記同様に１００ｍｍ間隔で３点測定し、その平均値を透過濃度とした。透過濃度は、５．０であった。
次いで、電離放射線硬化性樹脂である、Ｍ９０５０（東亞合成社製）、ＵＶ１７００Ｂ（日本合成社製）及び光重合開始剤であるイルガキュア１８４（ＢＡＳＦ社製）を組み合わせたものを、ハードコート層形成用組成物として、光透過性基材及び遮蔽層上に塗布し、紫外線照射で樹脂を半硬化させて、厚み１０μｍのハードコート被膜を形成した。
次に、形成したハードコート被膜の上に、中空状シリカ粒子、ＰＥＴ−３０（日本化薬社製）、Ｘ−２１−１６４Ｅ（信越化学工業社製）及び光重合開始剤であるイルガキュア１２７（ＢＡＳＦ社製）を組み合わせたものを、低屈折率層用組成物として塗布し、紫外線照射で含有する樹脂を硬化させて、厚み１００ｎｍの低屈折率層を形成するとともに、ハードコート被膜も完全に硬化させてハードコート層とし、反射防止性能を備えた光学積層体を作製した。作製した光学積層体については、ハードコート層側から遮蔽層の透過濃度を測定した。透過濃度は、透過濃度計３６１Ｔ（Ｘ−Ｒｉｔｅ社製）を用い、１００ｍｍ間隔で３点測定し、その平均値を透過濃度とした。その結果、遮蔽層の透過濃度は、５．０であった。
本実施例で作製した光学積層体は、遮蔽層が充分な厚み及び透過濃度を有しており、ドライバＩＣ等を問題なく遮蔽することができた。 Example 1
The polyethylene terephthalate material was melted at 290 ° C., extruded through a film-forming die, into a sheet form, closely adhered onto a water-cooled and cooled rotating quenching drum, and cooled to produce an unstretched film. This unstretched film was stretched at a stretching ratio of 4.5 times at a temperature of 120 ° C. with a biaxial stretching apparatus, and then stretched at a stretching ratio of 1.5 times in the direction of 90 degrees. A light-transmitting substrate having retardation = 8000 nm, film thickness = 80 μm, (nx−ny) = 0.10, and dimensional change rate 0.07% was obtained. The dimensional change rate of the light-transmitting substrate was measured using a thermomechanical analyzer (TMA / SS6000 manufactured by SII) and a circulation tank for humidity generation (PHOENIX II C25P manufactured by THERMO). More specifically, a 5 mm × 20 mm sample was cut out from the obtained light-transmitting substrate, and the sample was held for 300 min in a 30 ° C. 0% RH environment under a load condition of 150 mN / mm ² . Then, the dimension when held for 300 min in an environment of 30 ° C. and 90% RH was measured, and the dimensional change rate was calculated from these values by the following formula. The measurement direction is a slow axis direction and a direction orthogonal to the slow axis direction, and the average value thereof.

A composition for a shielding layer (black ink) obtained by kneading a carbon black pigment, a solvent, an additive and the like with urethane resin on one surface of the obtained light-transmitting substrate (product name: SS805 ink, Dainichi Seika) Kogyo Co., Ltd.) was used, and a frame-shaped shielding layer having a width of 12 mm was provided along the outer periphery of the light-transmitting substrate by gravure printing. To the black ink, 5 parts of an isocyanate curing agent (product name: Lamic B Hardener, manufactured by Dainichi Seika Kogyo Co., Ltd.) was added in order to enhance adhesion with the light transmissive substrate. The shielding layer was a three-layer black ink layer printed on the same plate so that it could not be seen through the fluorescent lamp. Thus, the shielding layer was sufficiently concealed (thickness 3.5 μm).
The thickness of the shielding layer was measured at three points on the shielding layer printing layer at 100 mm intervals in the vertical and horizontal directions using Digimatic Indicator ID-H0530 (manufactured by Mitutoyo), and the average value was defined as the printing thickness.
Further, the transmission density of the shielding layer was measured. The transmission density was measured using a transmission densitometer 361T (manufactured by X-Rite) at three points at 100 mm intervals as described above, and the average value was taken as the transmission density. The transmission density was 5.0.
Next, a combination of ionizing radiation curable resin, M9050 (manufactured by Toagosei Co., Ltd.), UV1700B (manufactured by Nippon Gosei Co., Ltd.) and Irgacure 184 (manufactured by BASF Corp.), a photopolymerization initiator, is used for forming a hard coat layer. The composition was applied onto a light transmissive substrate and a shielding layer, and the resin was semi-cured by ultraviolet irradiation to form a hard coat film having a thickness of 10 μm.
Next, on the formed hard coat film, hollow silica particles, PET-30 (manufactured by Nippon Kayaku Co., Ltd.), X-21-164E (manufactured by Shin-Etsu Chemical Co., Ltd.) and Irgacure 127 (photopolymerization initiator) A combination of BASF) is applied as a composition for a low refractive index layer, and the resin contained by UV irradiation is cured to form a low refractive index layer with a thickness of 100 nm, and the hard coat film is also completely An optical laminate having antireflection performance was prepared by curing to form a hard coat layer. About the produced optical laminated body, the transmission density of the shielding layer was measured from the hard-coat layer side. The transmission density was measured at three points at 100 mm intervals using a transmission densitometer 361T (manufactured by X-Rite), and the average value was taken as the transmission density. As a result, the transmission density of the shielding layer was 5.0.
In the optical laminate produced in this example, the shielding layer had a sufficient thickness and transmission density, and the driver IC and the like could be shielded without problems.

The obtained optical laminate was bonded in the order of a polarizer and a polarizer protective sheet to produce a polarizing plate integrated optical laminate. The optical laminated body polarizing plate-integrated optical laminated body includes a step of uniaxially stretching a PVA film, a step of dyeing the PVA film with a dichroic dye, and adsorbing the dichroic dye, The process of treating the adsorbed PVA film with an aqueous boric acid solution, the process of washing with water after the treatment with the boric acid aqueous solution, and polarizing the uniaxially stretched PVA film on which the dichroic dye is adsorbed and oriented by applying these processes The optical layered body thus obtained was manufactured through a process of attaching a polarizer protective sheet to one surface of the polarizer and the other surface.
At this time, the angle formed between the absorption axis of the polarizer and the slow axis of the light-transmitting substrate is 45 °. The polarizer protective sheet has a film thickness of 80 μm and a dimensional change rate of 0.76. % Triacetyl cellulose substrate (TD80ULM manufactured by Fuji Film Co., Ltd.) was used.

(Reference Example 1)
A shielding layer (thickness: 1.5 μm) was formed on one surface of the light-transmitting substrate in the same manner as in Example 1 except that the number of times of printing the black ink was set to 1.
Thereafter, in the same manner as in Example 1, a hard coat layer and a low refractive index layer were provided to produce an optical laminate having antireflection performance.
When the transmission density of the shielding layer was measured in the same manner as in Example 1 for the optical laminate produced in Reference Example 1, the transmission density was only 1.8, and the driver IC and the like could not be sufficiently shielded.

(Example 2)
By adjusting the draw ratio of the unstretched film obtained in the same manner as in Example 1, retardation = 4000 nm, film thickness = 80 μm, (nx−ny) = 0.05, dimensional change rate 0.07% light transmission A conductive substrate was obtained. A polarizing plate-integrated optical laminate was produced in the same manner as in Example 1 except that the obtained light-transmitting substrate was used.

(Comparative Example 1)
By adjusting the draw ratio of the unstretched film obtained in the same manner as in Example 1, retardation = 2800 nm, film thickness = 80 μm, (nx−ny) = 0.035, dimensional change rate 0.06% light transmission A conductive substrate was obtained.
A polarizing plate-integrated optical laminate was produced in the same manner as in Example 1 except that the obtained light-transmitting substrate was used.

(Comparative Example 2)
Retardation = 140 nm, film thickness 50 μm, dimension change rate: 0.001% ZEONOR (manufactured by Nippon Zeon Co., Ltd.) was used as a light-transmitting substrate in the same manner as in Example 1, but integrated with a polarizing plate. The body was manufactured.

(Comparative Example 3)
Unless you want to use a triacetyl cellulose base material (TD80ULM manufactured by Fujifilm) with an in-plane retardation of 5.6 nm, a film thickness of 80 μm, (nx−ny) = 0.00007, and a dimensional change rate of 0.76%, A polarizing plate integrated optical laminate was produced in the same manner as in Example 1.

A liquid crystal display device using the polarizing plate-integrated optical laminate obtained in Examples and Comparative Examples was produced.
The manufactured liquid crystal display device was compared with a commercially available image display device (BRAVIA KDL-32EX720 (manufactured by SONY), REGZA 46ZX9000 (manufactured by Toshiba)) having no bezel and having a bezel.
As a result, it was confirmed that the liquid crystal display device using the polarizing plate-integrated optical laminate obtained in Examples and Comparative Examples was superior to a commercially available image display device equipped with a bezel in flatness and thinness. did it.

(Nijimura evaluation)
Polarizer protection of the polarizing plate-integrated optical laminate produced in the examples and comparative examples instead of peeling off the polarizing plate installed on the observer side of the liquid crystal monitor (FLATRON IPS 226V (manufactured by LG Electronics Japan)) The sheet and the liquid crystal cell were installed via a pressure-sensitive adhesive (P-3132, manufactured by Lintec Corporation) to produce a liquid crystal display device.
In the dark and bright places (illuminance around the LCD monitor 400 lux), the display image is observed visually and through polarized sunglasses from the front and diagonal directions (about 50 degrees), and the presence or absence of nidimra is evaluated according to the following criteria. did. Observation through polarized sunglasses is a much stricter evaluation method than visual observation. The observation is performed by 10 people, and the largest number of evaluations are the observation results. The results are shown in Table 1.
◎: Nizimura is not observed ○: Nizimura is observed, but there is no problem in practical use △: Nizimura is observed thinly ×: Nizimura is observed strongly

(Evaluation of color change)
Polarizer protection of the polarizing plate-integrated optical laminate produced in the examples and comparative examples instead of peeling off the polarizing plate installed on the observer side of the liquid crystal monitor (FLATRON IPS 226V (manufactured by LG Electronics Japan)) The sheet and the liquid crystal cell were installed via a pressure sensitive adhesive (P-3132, manufactured by Lintec Corporation) to produce a liquid crystal display device. When the liquid crystal monitor is displayed in white and the angle between the polarizing sunglasses absorption axis and the absorption axis of the polarizing plate on the observer side of the liquid crystal monitor is 0 degrees (parallel Nicols), and 90 degrees (crossed Nicols) The front color was measured with a luminance meter BM-5 (manufactured by Topcon Corporation), and the color difference Δu′v ′ was calculated. At the same time, observation was performed by 10 people, and evaluation (sensory evaluation) was performed according to the following criteria. The most numerous evaluations are the observation results. The results are shown in Table 1.
A: There is no color difference between parallel and crossed Nicols.
○: There is a slight color difference between parallel Nicol and cross Nicol, but there is no problem in actual use.
X: There is a color difference between parallel Nicol and cross Nicol.

(Curl evaluation)
Polarizer protection of the polarizing plate-integrated optical laminate produced in the examples and comparative examples instead of peeling off the polarizing plate installed on the observer side of the liquid crystal monitor (FLATRON IPS 226V (manufactured by LG Electronics Japan)) The sheet and the liquid crystal cell were installed via a pressure-sensitive adhesive (P-3132, manufactured by Lintec Corporation) to prepare a liquid crystal cell having a polarizing plate integrated optical laminate. The liquid crystal cell having the polarizing plate integrated optical laminate was allowed to stand for 1 week at 30 ° C. and 60% RH, and then the curl amount was measured. The curl was measured by placing the convex surface of the curl on a horizontal table and measuring the height from the table to the end surface with the largest curl. The curl is indicated by a value C / S obtained by dividing the curl value by the inch size of the liquid crystal monitor.
In the same manner, a liquid crystal monitor having a polarizing plate-integrated optical laminate was prepared, and left for one week under conditions of 30 ° C. and 60% RH. According to the standard, the usability was evaluated (sensory evaluation). The most numerous evaluations are the observation results.
○: Since the curl of the liquid crystal cell is small, there is no close contact with the backlight, and no display quality deterioration such as moire or luminance unevenness is observed.
X: Moire or luminance unevenness has occurred, and the display quality has deteriorated.

From Table 1, the liquid crystal display device using the polarizing plate integrated optical laminate according to the example gave good results in all evaluations.
On the other hand, the liquid crystal display device using the polarizing plate-integrated optical laminate according to Comparative Example 1 had a small retardation of the light-transmitting substrate, and was inferior in evaluation of nitrile and color change. The liquid crystal display device using the polarizing plate integrated optical laminate according to Comparative Example 2 was inferior in color change. In addition, the liquid crystal display device using the polarizing plate-integrated optical laminate according to Comparative Example 3 is excellent in Nizimura evaluation, but is not visible when observed through polarized sunglasses, and the humidity of the light-transmitting substrate. The dimensional change rate with respect to the change was large, and the curl evaluation was inferior.

The polarizing plate integrated optical laminate of the present invention includes a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a field emission display (FED), a touch panel, and electronic paper. It can be suitably applied to tablet PCs and the like.

DESCRIPTION OF SYMBOLS 10 Polarizing plate integrated optical laminated body 11 Polarizing element film 12 Light transmissive base material 13 Shielding layer 14 Hard coat layer

Claims (6)

A polarizing plate-integrated optical laminate that is disposed on the display screen side of the image display panel and the optical laminate is laminated on the polarizing element film,
The optical laminate includes a light-transmitting substrate having a birefringence index in a plane, a shielding layer formed along an outer periphery of the light-transmitting substrate on the side surface opposite to the polarizing element film, and the light. Having a hard coat layer provided on the transparent substrate and the shielding layer;
The light-transmitting substrate has a retardation of 3000 nm or more,
A polarizing plate-integrated optical laminate, wherein a light transmissive substrate of the optical laminate is provided on the polarizing element film. The light-transmitting substrate having a birefringence in the plane is an angle formed by the slow axis direction, which is the direction having the largest refractive index in the plane of the light-transmitting substrate, and the absorption axis direction of the polarizing element film. 2. The polarizing plate-integrated optical laminate according to claim 1, which is laminated so as to be in a range of 45 ° ± 15 °. The polarizing plate-integrated optical laminate according to claim 1 or 2, wherein the shielding layer is formed in a region that conceals a driver IC that drives the image display panel when observed from the display screen side. The polarizing plate-integrated optical laminate according to claim 1, wherein the shielding layer has a thickness of 2.0 to 5.0 μm. The polarizing plate-integrated optical laminate according to claim 1, wherein the shielding layer has a transmission density of 3.0 to 5.6. An image display device comprising the polarizing plate-integrated optical laminate according to claim 1, 2, 3, 4 or 5.

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