KR20080002685A - Manufacturing method of adhesive optical film, adhesive optical film and image display apparatus - Google Patents

Abstract

A method for manufacturing an adhesive optical film, the adhesive optical film and an image display apparatus are provided to reduce a polymerizable unsaturated group remaining in a discotic liquid crystal layer by radiating UV or visible rays on the discotic liquid crystal layer before forming an adhesive layer on the discotic liquid crystal layer, thereby restraining the stain of a window frame caused by an increase of a front phase difference value. An adhesive optical film has a discotic liquid crystal layer(3) on a side of a transparent film(1). A method for manufacturing the adhesive optical film comprises the following steps of: radiating UV(Ultra Violet) rays or visible rays on the surface of the discotic liquid crystal layer; forming an undercoating layer(4); and forming an adhesive layer(5). The undercoating layer forming process is replaced with a process of forming the adhesive layer on the discotic liquid crystal layer without forming the undercoating layer.

Description

A manufacturing method of an adhesive optical film, an adhesive optical film, and an image display apparatus {MANUFACTURING METHOD OF ADHESIVE OPTICAL FILM, ADHESIVE OPTICAL FILM AND IMAGE DISPLAY APPARATUS}

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the flow of the manufacturing method of the adhesive optical film which concerns on this invention.

The figure which shows the flow of the manufacturing method of the adhesive optical film which concerns on this invention.

The figure which shows the flow of the manufacturing method of the adhesive optical film which concerns on this invention.

* Description of the symbols for the main parts of the drawings

1: transparent base film

2: alignment film

3: discotic liquid crystal layer

4: sub-floor

5: adhesive layer

6: polarizer

7: transparent protective film

Patent Document 1: Japanese Patent Application Laid-Open No. 8-95032

Patent Document 2: Japanese Patent No. 2767382

The present invention relates to a method for producing a pressure-sensitive optical film. Moreover, this invention relates to the image display apparatuses, such as the liquid crystal display device, organic electroluminescence display, CRT, PDP which used the adhesive optical film obtained by the said manufacturing method, and also the said adhesive optical film.

The pressure-sensitive adhesive optical film of the present invention has a discotic liquid crystal layer in which a discotic liquid crystal compound is oriented, and is useful as an optical compensation film for improving visual characteristics of display contrast and display color, and in particular, laminating polarizers. One is useful as an elliptical polarizer with optical compensation.

Liquid crystal displays are rapidly expanding in markets such as watches, mobile phones, PDAs, notebook computers, PC monitors, DVD players, and TVs. The liquid crystal display device visualizes the change in the polarization state due to the switching of the liquid crystal, and a polarizer is used from the display principle. In particular, applications such as TVs are increasingly required to display high contrast and high contrast, and brighter (high transmittance) and higher contrast (higher polarization) light polarizers have been developed and introduced.

At present, the mainstream system of a general liquid crystal display device is a TFT-LCD using a TN liquid crystal. This method has advantages such as fast response speed and high contrast. However, when the display of the panel using the TN liquid crystal is viewed at an angle inclined from its normal direction, the contrast is considerably lowered, and gray scale inversion such that the gray scale display is reversed occurs. It is narrow. On the other hand, in the use of a large PC monitor, a television, etc., the change of the display color by high contrast, a wide viewing angle, and a viewing angle is calculated | required. Therefore, when using the TFT-LCD of TN mode for such a use, the retardation film for compensating a viewing angle is indispensable.

As this retardation film, the stretched birefringent polymer film has been used conventionally. In recent years, it has been proposed to use an optical compensation film having an optically anisotropic layer formed of liquid crystalline molecules on a transparent support instead of the optical compensation film made of a stretched birefringent film. Since the liquid crystal molecules have various alignment forms, the use of liquid crystal molecules makes it possible to realize optical properties that cannot be obtained in conventional stretched birefringent polymer films.

As the retardation film for viewing angle compensation as described above, for example, a wide view film manufactured by Fuji Photo Film Co., Ltd. using discotic liquid crystals having negative refractive index anisotropy has been proposed (Patent Document 1, Patent Document 2). Reference). In this retardation film, the optical axis has the discotic liquid crystal layer in which the optical axis was diagonally aligned on one side of the transparent base film. In this retardation film, the objective is mainly to improve the viewing angle characteristic in the voltage application state of a black display. That is, in the voltage application state, the liquid crystal molecules in a liquid crystal cell show positive refractive index anisotropy which has the optical axis inclined from the glass substrate. In order to compensate the phase difference by this refractive index anisotropy, the optical axis is inclined from the film normal direction and becomes the phase difference film using the liquid crystalline molecule which has negative refractive index anisotropy.

In the retardation film for viewing angle compensation, a polarizer is laminated on the transparent base film and used as an elliptically polarizing plate, while an adhesive layer is laminated on the discotic liquid crystal layer. A pressure-sensitive adhesive optical film such as a phase difference film or an elliptically polarizing plate in which the pressure-sensitive adhesive layer is laminated is attached to a liquid crystal cell or the like through the pressure-sensitive adhesive layer and used. However, when the liquid crystal display device etc. which attached the above-mentioned retardation film for viewing angle compensation or an elliptical polarizing plate attached to the liquid crystal cell etc. through the adhesive layer are combined with a backlight (lighting state), it will be uneven in the frame vicinity of a liquid crystal display device (hereinafter, This is called a window frame stain.) There was a problem of lowering visibility. In particular, when the temperature is increased or the size of the liquid crystal display device is increased, the window frame unevenness becomes remarkable.

The present invention is a pressure-sensitive adhesive optical film having a discotic liquid crystal layer in which a discotic liquid crystal compound is oriented on one side of a transparent base film, and an adhesive layer is laminated on the discotic liquid crystal layer, in a state where the backlight is turned on. An object of the present invention is to provide a method for producing a pressure-sensitive adhesive optical film that can suppress window frame staining.

Moreover, an object of this invention is to provide the adhesive optical film obtained by the said manufacturing method, and also to provide the image display apparatus using the said adhesive optical film.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, the present inventors discovered that the said objective can be achieved by the manufacturing method of the following adhesive optical film, and came to complete this invention.

That is, this invention is the process of forming an adhesive layer in the said discotic liquid crystal layer of the optical film which has the discotic liquid crystal layer formed by the orientation and hardening of the discotic liquid crystal compound which has a polymerizable unsaturated group on the single side | surface of a transparent base film. In the method for producing a pressure-sensitive adhesive optical film, before the step of forming the pressure-sensitive adhesive layer, ultraviolet light and / or visible light is irradiated to the discotic liquid crystal layer, and the method for manufacturing the pressure-sensitive adhesive optical film. will be.

In the manufacturing method of the said adhesive optical film, it can have the process of forming an undercoat layer after irradiating an ultraviolet light and / or visible light, and before performing the process of forming an adhesive layer.

In the manufacturing method of the said adhesive optical film, it is preferable that irradiation light contains an ultraviolet light and the accumulated light amount in wavelength 350nm is 10-10000mJ / cm <2>.

In the manufacturing method of the said adhesive optical film, it is preferable that the single side | surface of the transparent base film in which a discotic liquid crystal layer is formed is a rubbing process, or the orientation film is formed.

In the manufacturing method of the said adhesive optical film, what has a polarizer laminated on the single side | surface of the transparent base film of the side in which the discotic liquid crystal layer is not formed can be used as an optical film.

In the manufacturing method of the said adhesive optical film, after performing the process of forming an adhesive layer, you may have a process of laminating | stacking a polarizer on the single side | surface of the transparent base film of the side in which the discotic liquid crystal layer is not formed.

Moreover, this invention relates to the adhesive optical film obtained by the said manufacturing method.

Moreover, this invention relates to the image display apparatus which used at least one said adhesive optical film. The pressure-sensitive adhesive optical film of the present invention is used in combination of one or a plurality of films according to various usage aspects of an image display device such as a liquid crystal display device.

Implement the invention  Best form for

Hereinafter, the present invention will be described with reference to the drawings. As shown in FIG. 1, the optical film of this invention has the discotic liquid crystal layer 3 on the single side | surface of the transparent base film 1. As shown in FIG. The discotic liquid crystal layer 3 is formed by the orientation and curing of a discotic liquid crystal compound having a polymerizable unsaturated group. In FIG. 1, although the case where the alignment film 2 is formed between the transparent base film 1 and the discotic liquid crystal layer 3 is illustrated, instead of the alignment film 2, the single side | surface of the transparent base film 1 is rubbed. The treatment can be used.

In FIG. 1 (1), ultraviolet light and / or visible light are irradiated to the surface of the discotic liquid crystal layer 3. Thereby, while reducing the polymerizable unsaturated group remaining in the discotic liquid crystal layer 3, hardness is raised. Moreover, although irradiation light is irradiated from the discotic liquid crystal layer 3 side in FIG. 1 (1), irradiation can also be performed from the transparent base film side.

Subsequently, as shown in FIG. 1 (2), after forming the undercoating layer 4, as shown in FIG. 1 (3), the adhesive layer 5 is formed and the adhesive optical film of this invention is produced. In addition, the process of forming the undercoating layer 4 shown in FIG. 1 (2) is arbitrary, as shown in FIG. 1 (3 '), without forming the undercoating layer 4, on the discotic liquid crystal layer 3 The adhesive layer 5 can be formed in.

FIG. 2 is an optical film, on one side of the transparent base film 1, having a discotic liquid crystal layer 3 via an alignment film 2, and on the side where the discotic liquid crystal layer 3 is not formed ( It is a case where the polarizer 6 and the transparent protective film 7 are laminated | stacked on the single side | surface of 1). In FIG. 2, the transparent base film 1 also serves as a transparent protective film of the polarizer 6. As shown in FIG. 2, the process similar to FIG. 1 can also be performed also about the optical film which has a polarizing plate, while reducing the polymerizable unsaturated group which remains in the discotic liquid crystal layer 3, hardness can be raised.

FIG. 3 is a polarizer 6, then transparent protection, on one side of the transparent base film 1 on the side where the discotic liquid crystal layer 3 is not formed in the pressure-sensitive adhesive optical film obtained in FIG. 1 (3). The case where the optical film which has the polarizing plate which laminated | stacked the film 7 is manufactured is shown. In FIG. 3, the transparent base film 1 also serves as a transparent protective film of the polarizer 6.

In this invention, the optical film which has the discotic liquid crystal layer 3 on the single side | surface of the transparent base film 1 is used.

In the transparent base film, various transparent materials can be used. For example, polyester polymers, such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers, such as diacetyl cellulose and triacetyl cellulose, acrylic polymers, such as polymethyl methacrylate, a polystyrene, an acrylonitrile styrene copolymer Styrene-type polymers, such as (AS resin), a polycarbonate polymer, etc. are mentioned. Further, polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, polyolefin-based polymers such as ethylene-propylene copolymers, amide-based polymers such as vinyl chloride-based polymers, nylon and aromatic polyamides, imide-based polymers, and sulfides Phone polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer, Epoxy-based polymers, blends of the polymers, and the like are also exemplified as examples of the polymer forming the transparent base film.

Furthermore, the polymer film described in JP 2001-343529 A (WO01 / 37007), for example, a thermoplastic resin having a substituted and / or unsubstituted imide group in the (A) side chain, and a (B) side chain, And / or a resin composition containing a thermoplastic resin having unsubstituted phenyl and nitrile groups. As a specific example, the film of the resin composition containing the alternating copolymer which consists of isobutylene and N-methyl maleimide, and an acrylonitrile styrene copolymer is mentioned. As a film, the film which consists of a mixed extrusion product of a resin composition, etc. can be used.

Although the thickness of a transparent base film can be suitably determined, it is generally about 1-500 micrometers from a viewpoint of workability, thin-film property, etc., such as strength and handleability. In particular, 5-200 micrometers is preferable.

Moreover, it is preferable that a transparent base film does not become color as much as possible. Therefore, the phase difference in the film thickness direction represented by Rth = (nx-nz) .d (where nx is the refractive index in the slow axis direction in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness) is -90. The transparent base film which is nm-+75 nm can be used preferably. By using what is the phase difference value (Rth) of -90 nm-+75 nm in such thickness direction, coloring (optical coloring) of the polarizing plate resulting from a transparent base film can be almost eliminated. The thickness direction retardation Rth is more preferably -80 nm to +60 nm, particularly -70 nm to +45 nm.

As a transparent base film, cellulose polymers, such as triacetyl cellulose, and norbornene-type polymer are preferable from a viewpoint of polarization characteristic, durability, etc. In particular, cellulose polymers, such as triacetyl cellulose, are preferable.

The discotic liquid crystal layer is formed by the orientation and curing of a discotic liquid crystal compound having a polymerizable unsaturated group. The discotic liquid crystal layer is useful as an optical compensation layer, and can improve viewing angle, contrast, brightness, and the like. The discotic liquid crystal compound has a polymerizable unsaturated group, and the discotic liquid crystal layer is formed by aligning and curing the compound. It is preferable that the discotic liquid crystal layer has the discotic liquid crystal compound oriented diagonally. The thickness of a discotic liquid crystal layer is about 0.5-10 micrometers normally.

A discotic liquid crystal compound has negative refractive index anisotropy (uniaxiality), for example, the research report of C. Destrade, Mol. Cryst. A study of the benzene derivatives described in Vol. 71, p. 111 (1981), or by B. Kohne, Angew. Chem. A study of the cyclohexane derivatives described in Volume 96, page 70 (1984) and J. M. Lehn, J. Chem. Commun., Page 1794 (1985), J. Zhang's report, J. Am. Chem. Soc. Azacrown-based or phenylacetylene-based macrocycles as described in Volume 116, page 2655 (1994). In general, these are used as mother-based nuclei, and linear alkyl groups, alkoxy groups, substituted benzoyloxy groups, etc. The linear chain is a structure substituted radially, exhibits liquid crystallinity, and generally includes a discotic liquid crystal. However, as long as the molecule itself has negative uniaxiality and can provide a constant orientation, it is not limited to the above description. In the present invention, the discotic liquid crystal compound may be a polymerizable unsaturated group which is cured by heat, light, or the like (eg, acryloyl group, methacryloyl group, vinyl group, allyl group, etc.). To have. Moreover, the discotic liquid crystal layer does not need to be the said compound finally, The thing which superposed | polymerized or bridge | crosslinked by reaction of a polymerizable unsaturated group, became high molecular weight, and includes the thing which lost liquid crystallinity.

In addition, the discotic liquid crystal compound is optically negatively monoaxial, such as a reaction product of a discotic liquid crystal compound which is no longer exhibiting liquid crystal by reaction with various discotic liquid crystal compounds and other low molecular weight compounds or polymers. It means the whole compound which has.

In the orientation treatment of the discotic liquid crystal, the surface of the transparent substrate film is subjected to a rubbing treatment or an alignment film is used. Examples of the alignment film include an inorganic film deposited film or an alignment film obtained by rubbing a specific organic polymer film. There is also a thin film in which isomerization occurs by light, such as an LB film made of an azobenzene derivative, and molecules are arranged in a uniform direction. As an organic alignment film, the organic polymer film which forms hydrophobic surfaces, such as a polyimide film, alkyl chain modified system foaming, polyvinyl butyral, and polymethyl methacrylate, is mentioned. In addition, an SiO film deposited film is mentioned as an inorganic film deposited film.

The discotic liquid crystal compound is obliquely oriented. As the means, for example, an alignment film is formed on a transparent base film, and then a discotic liquid crystal compound (polymerizable liquid crystal compound) is applied to be in an oblique alignment state. It is possible to use a method such as fixation by light irradiation or heat such as ultraviolet light. In addition, it is also possible to form the discotic liquid crystal by tilting the alignment on another alignment substrate, and then to form the transfer by using an optically clear adhesive or a pressure-sensitive adhesive on a transparent support.

As such a discotic liquid crystal layer, the thing of patent document 1, 2 is used preferably. As a diagonal alignment layer of such discotic liquid crystal is formed on a cellulose-based polymer film, there is a wide view film manufactured by Fuji Photo Film.

In the present invention, the discotic liquid crystal layer is irradiated with ultraviolet light and / or visible light. Irradiation of ultraviolet light and / or visible light reduces the remaining polymerizable unsaturated group. In addition, the surface hardness of the discotic liquid crystal layer is increased. By the said irradiation, it is preferable to irradiate so that the hardness of a discotic liquid crystal layer may become about 0.02-0.12 GPa. Moreover, although the hardness of a discotic liquid crystal layer changes with the material used for formation of a discotic liquid crystal layer, it is preferable that the hardness of the discotic liquid crystal layer before the said irradiation is about 0.11-0.16 GPa normally, The discotic liquid crystal after the said irradiation It is preferable that the hardness of a layer is about 0.17-0.24 GPa normally.

For the polymerizable unsaturated groups to remain, IR spectrum of the ^1510cm-1 (aromatic-derived) and 811cm ^-1 - absorbance of the (carbon-carbon double bond derived) ratio (811cm ^-1 / 1510cm ^-1) is identified by being reduced have. By the said irradiation, it is preferable to irradiate so that the absorbance ratio of a discotic liquid crystal layer may be reduced about 0.04-0.18. Moreover, it is preferable that the absorbance ratio of the discotic liquid crystal layer before the said irradiation is about 0.23-0.30 normally, and it is preferable that the absorbance ratio of the discotic liquid crystal layer after the said irradiation is about 0.12-0.19 normally.

Ultraviolet light and / or visible light are used for the said irradiation light. It is preferable that the accumulated light amount of irradiation light is 10-10000mJ / cm <2> normally. By the accumulated light amount in this range, the surface treatment of the discotic liquid crystal layer can be effectively performed.

As irradiation light, it is preferable that ultraviolet light is included and the accumulated light quantity in wavelength 350nm is the said range. In the case of containing ultraviolet light, it is preferable in that the irradiation time can be shortened and efficiency can be achieved.

The pressure-sensitive adhesive layer is formed on the discotic liquid crystal layer irradiated with the ultraviolet light and / or the visible light, and the undercoat layer may be formed before the process of forming the pressure-sensitive adhesive layer.

Examples of the material for forming the undercoat layer include urethane (polyisocyanate), polyester, acrylic, polyamide, melamine, olefin, polystyrene, epoxy, phenol, isocyanurate, Materials, such as a polyvinyl acetate type and a silane coupling agent, are mentioned. The undercoat layer can improve the adhesiveness with an adhesive layer. Another function can also be provided to the said formation material by adding functional additives, such as a crosslinking agent and an antistatic agent for crosslinking hardening.

As a lamination method of the undercoat layer, various lamination methods can be suitably selected according to the kind of undercoat layer forming material. For example, methods, such as extrusion lamination and dry lamination by film forming, the method of drying and solidifying after coating, etc. can be employ | adopted. The thickness of the undercoat layer is usually 1 µm or less, preferably 10 to 500 nm.

The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer is not particularly limited, and various pressure-sensitive adhesives such as rubber pressure-sensitive adhesives, acrylic pressure-sensitive adhesives and silicone pressure-sensitive adhesives can be used. Acrylic pressure-sensitive adhesives having colorless transparency and good adhesion to liquid crystal cells and the like are generally used.

The acrylic pressure sensitive adhesive has an acrylic polymer having a monomer unit of alkyl (meth) acrylate as a main skeleton as a base polymer. In addition, (meth) acrylate means an acrylate and / or methacrylate, and is the same meaning as the (meth) of this invention. The average carbon number of the alkyl group of the alkyl (meth) acrylate which comprises the main skeleton of an acryl-type polymer is about 1-12, and methyl (meth) acrylate and ethyl (meth) are mentioned as a specific example of alkyl (meth) acrylate. Acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, etc. can be illustrated. These may be used alone or in combination. Among these, alkyl (meth) acrylates having 1 to 9 carbon atoms of the alkyl group are preferable.

In the said acryl-type polymer, one or more types of various monomers are introduce | transduced by copolymerization in order to improve adhesiveness and heat resistance. As a specific example of such a copolymerization monomer, it is (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid 4-hydroxybutyl, (meth) acrylic acid 6, for example. -Hydroxyhexyl, (meth) acrylic acid 8-hydroxyoctyl, (meth) acrylic acid 10-hydroxydecyl, (meth) acrylic acid 12-hydroxylauryl, (4-hydroxymethylcyclohexyl) -methylacrylate, etc. Hydroxyl group-containing monomers; Carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid; Acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; Caprolactone adducts of acrylic acid; Containing sulfonic acid groups such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, and (meth) acryloyloxynaphthalene sulfonic acid Monomers; Phosphoric acid group containing monomers, such as 2-hydroxyethyl acryloyl phosphate, etc. are mentioned.

Moreover, a nitrogen containing vinyl monomer is mentioned. For example, maleimide, N-cyclohexylmaleimide, N-phenylmaleimide; N-acryloyl morpholine; (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methyl (meth) acrylamide, N-butyl (N-substituted) amide monomers such as (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-methylolpropane (meth) acrylamide; Amino ethyl (meth) acrylate, aminopropyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, 3- (3-pyridyl) propyl (meth) acrylate (Meth) acrylic-acid alkylaminoalkyl type monomers, such as these; Alkoxy alkyl (meth) acrylate monomers, such as (meth) acrylic-acid methoxyethyl and (meth) acrylate ethoxyethyl; N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, N Succinimide type monomers, such as acryloyl morpholine, etc. are mentioned as a monomer example for the purpose of modification.

In addition, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole Vinyl monomers such as vinyl morpholine, N-vinyl carboxylic acid amides, styrene, α-methylstyrene, and N-vinyl caprolactam; Cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; Epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; Glycol-based acrylic ester monomers such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, and methoxypolypropylene glycol (meth) acrylate; Acrylic acid ester type monomers, such as (meth) acrylic acid tetrahydrofurfuryl, fluorine (meth) acrylate, silicone (meth) acrylate, and 2-methoxyethyl acrylate, can also be used.

Among these, carboxyl group-containing monomers, such as acrylic acid, are used preferably from a viewpoint of adhesiveness with respect to a liquid crystal cell, and adhesive durability.

Although the ratio of the said copolymerization monomer in an acrylic polymer is not specifically limited, It is preferable that it is about 0.1 to 10% in a weight ratio.

The average molecular weight of the acrylic polymer is not particularly limited, but the weight average molecular weight is preferably about 300,000 to 2.5 million. The acrylic polymer can be produced by various known methods, and for example, a radical polymerization method such as a bulk polymerization method, a solution polymerization method or a suspension polymerization method can be appropriately selected. As a radical polymerization initiator, various well-known thing of azo type and a peroxide type can be used. Reaction temperature is about 50-80 degreeC normally, and reaction time is 1 to 8 hours. Moreover, the solution polymerization method is preferable among the said manufacturing methods, and ethyl acetate, toluene, etc. are generally used as a solvent of an acryl-type polymer. The solution concentration is usually about 20 to 80% by weight.

As the base polymer of the rubber-based adhesive, for example, natural rubber, isoprene-based rubber, styrene-butadiene-based rubber, recycled rubber, polyisobutylene-based rubber, and styrene-isoprene-styrene-based rubber, styrene-butadiene-styrene Type rubber etc. are mentioned. As a base polymer of a silicone type adhesive, dimethyl polysiloxane, diphenyl polysiloxane, etc. are mentioned, for example, The base polymer can also use what introduce | transduced functional groups, such as a carboxyl group.

Moreover, it is preferable to set it as the adhesive composition containing a crosslinking agent. As a polyfunctional compound which can be mix | blended with an adhesive, an organic type crosslinking agent and a polyfunctional metal chelate are mentioned. As an organic type crosslinking agent, an epoxy type crosslinking agent, an isocyanate type crosslinking agent, an imine type crosslinking agent, etc. are mentioned. As an organic type crosslinking agent, an isocyanate type crosslinking agent is preferable. A polyfunctional metal chelate is a thing in which a polyvalent metal is covalently bonded or coordinated with an organic compound. Examples of the polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. have. As an atom in the organic compound covalently bonded or coordinated, an oxygen atom etc. are mentioned, As an organic compound, an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, a ketone compound, etc. are mentioned.

Although the compounding ratio of a base polymer, such as an acrylic polymer, and a crosslinking agent is not specifically limited, Usually, about 0.01-6 weight part of crosslinking agents (solid content) is preferable with respect to 100 weight part of base polymers (solid content), and about 0.1-3 weight part is More preferred.

In the pressure-sensitive adhesive, a tackifier, plasticizer, glass fiber, glass beads, metal powder, other inorganic powder, or the like, a filler, a pigment, a colorant, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent, etc. may be used as necessary. Moreover, various additives can also be used suitably in the range which does not deviate from the objective of this invention. Moreover, it is good also as an adhesive layer etc. which contain microparticles | fine-particles and show light diffusivity.

Formation of an adhesive layer is performed by laminating | stacking on the said discotic liquid crystal layer or the undercoat layer. It does not restrict | limit especially as a formation method, The method of apply | coating and drying an adhesive (solution), the method of transferring by the release sheet which provided the adhesive layer, etc. are mentioned. As the coating method, a roll coating method such as reverse coating or gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dipping method, a spray method, or the like can be adopted. Although the thickness (dry film thickness) of an adhesive layer is not specifically limited, It is preferable to set it as about 10-40 micrometers.

In the pressure-sensitive adhesive optical film of the present invention, window frame stains are likely to occur when the pressure-sensitive adhesive layer is thin. Therefore, the adhesive optical film of this invention is especially preferable when the thickness of an adhesive layer is 5-40 micrometers, and also thinner like 5-25 micrometers. Moreover, in the pressure-sensitive adhesive optical film of the present invention, window frame stains are likely to occur when the pressure-sensitive adhesive layer is hard.

As a constituent material of the release sheet, a suitable thin body such as a synthetic resin film such as paper, polyethylene, polypropylene, polyethylene terephthalate, rubber sheet, paper, cloth, nonwoven fabric, net, foam sheet, metal foil, laminate thereof, or the like ( And the like. In order to improve the peelability from an adhesive layer, the peeling process, such as a silicone treatment, a long chain alkyl treatment, a fluorine treatment, may be performed on the surface of the release sheet 4 as needed.

As a constituent material of a release sheet, suitable thin films, such as synthetic resin films, such as paper, polyethylene, a polypropylene, and a polyethylene terephthalate, a rubber sheet, paper, cloth, a nonwoven fabric, a net, a foam sheet, a metal foil, those laminates, etc. Can be mentioned. In order to improve the peelability from an adhesive layer, the surface of a release sheet may be given low adhesive peeling processes, such as a silicone process, a long chain alkyl process, and a fluorine process, as needed.

As for the optical film of this invention, as shown in FIG. 2, the polarizer 6 and then the transparent protective film 7 are laminated | stacked on the single side | surface of the transparent base film 1 of the side in which the discotic liquid crystal layer 3 is not formed. It can be used. In addition, as shown in FIG. 3, the polarizer 6 and then the transparent protective film 7 are attached to the single side | surface of the transparent base film 1 of the side where the discotic liquid crystal layer 3 is not formed as an adhesive optical film. The optical film which has a laminated polarizing plate can be manufactured.

The polarizer 6 is attached to the transparent base film 1 using an adhesive agent. In addition, in FIG.2 and FIG.3, although the transparent base film 1 serves as the transparent protective film of the polarizer 6, the transparent base film 1 is laminated | stacked the polarizing plate which has a transparent protective film on the single side | surface or both surfaces of a polarizer. You may.

A polarizer is not specifically limited, Various things can be used. As a polarizer, for example, a dichroic substance such as iodine or a dichroic dye is adsorbed onto hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymerized partial saponified films. And polyene-based alignment films such as monoaxially stretched, dehydrated polyvinyl alcohol and dehydrochloric acid treated polyvinyl chloride. Especially, the polarizer which consists of dichroic substances, such as a polyvinyl alcohol-type film and iodine, is preferable. Although the thickness in particular of these polarizers is not restrict | limited, Usually, it is about 5-80 micrometers.

The polarizer which uniaxially stretched the polyvinyl alcohol-type film by iodine, for example, can be produced by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it by 3 to 7 times its original length. As needed, it can also be immersed in aqueous solution, such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride, etc. If necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. In addition to washing the polyvinyl alcohol-based film with water, the contamination of the polyvinyl alcohol-based film with the antiblocking agent can be washed, and the polyvinyl alcohol-based film is swollen to prevent nonuniformity such as staining. Stretching may be performed after dyeing with iodine, or may be performed while dyeing, or may be dyed with iodine after stretching. It can extend | stretch also in aqueous solution, such as boric acid and potassium iodide, and a water bath.

As a material which forms the transparent protective film formed on the single side | surface or both surfaces of the said polarizer, it is preferable that it is excellent in transparency, mechanical strength, heat stability, moisture shielding property, isotropy, etc. The material similar to a transparent base film can be used for a transparent protective film. The same applies to the thickness.

Moreover, the same polymer material may be used for a transparent base film and a transparent protective film, and a different polymer material etc. may be used.

The polarizer, the transparent base film and the transparent protective film are usually in close contact with each other through an aqueous adhesive or the like. As an aqueous adhesive agent, an isocyanate adhesive, a polyvinyl alcohol adhesive, a gelatin adhesive, a vinyl latex type, an aqueous polyurethane, an aqueous polyester, etc. can be illustrated. Moreover, when attaching a polarizer, a transparent base film, and a transparent protective film, an activation process can be given to a transparent base film and a transparent protective film. Various methods can be adopted for the activation treatment, and for example, saponification treatment, corona treatment, low pressure UV treatment, plasma treatment and the like can be adopted. The activation treatment is effective when the transparent base film is particularly triacetyl cellulose, norbornene-based resin, polycarbonate, polyolefin resin or the like.

The surface which did not adhere the polarizer of the said transparent protective film may be the thing which performed the process for the purpose of a hard-coat layer, an anti-reflective process, sticking prevention, and diffused or anti-glare.

The hard coat treatment is carried out for the purpose of preventing scratches on the surface of the polarizing plate, and for example, a method of adding a cured film having excellent hardness and sliding properties by suitable ultraviolet curable resins such as acrylic and silicone to the surface of the transparent protective film. And the like can be formed. The antireflection treatment is performed for the purpose of preventing reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. In addition, the sticking prevention process is performed for the purpose of preventing adhesion with the adjacent layer of another member.

In addition, antiglare treatment is carried out for the purpose of preventing external light from being reflected on the surface of the polarizing plate and impairing the visibility of the transmitted light of the polarizing plate, for example, a roughening method or a transparent method using a sandblasting method or an embossing method. It can form by providing a fine concavo-convex structure to the surface of a transparent protective film by a suitable method, such as a compounding method of microparticles | fine-particles. As microparticles | fine-particles contained in formation of the said surface fine uneven | corrugated structure, it has electroconductivity which consists of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide etc. which have an average particle diameter of 0.5-50 micrometers, for example. In some cases, transparent fine particles such as organic fine particles (including beads) made of inorganic fine particles, crosslinked or uncrosslinked polymers, and the like can be used. When forming a surface fine uneven structure, the usage-amount of microparticles | fine-particles is about 2-50 weight part generally with respect to 100 weight part of transparent resin which forms a surface fine uneven structure, and 5-25 weight part is preferable. The antiglare layer may also serve as a diffusion layer (visual magnification function or the like) for diffusing the polarizing plate transmitted light to enlarge the time and the like.

In addition, the antireflection layer, the sticking prevention layer, the diffusion layer, the antiglare layer, and the like can be formed not only on the transparent protective film itself but also as a separate optical layer, and can be formed separately from the transparent protective film.

Moreover, in addition to the optical film which laminated | stacked the said polarizing plate, as an optical film used for the adhesive optical film of this invention, the optical layer used for formation of image display apparatuses, such as a liquid crystal display device, can be laminated | stacked. For example, an optical layer that may be used to form a liquid crystal display device such as a reflector plate, a semi-transmissive plate, a retardation plate (including a wave plate such as 1/2 or 1/4), and a brightness enhancement film Can be. Not only can these be used as an optical film independently, they can be laminated | stacked on the said polarizing plate at the time of practical use, and can be used 1 layer or 2 or more layers.

In particular, a reflection type polarizing plate or a semi-transmissive polarizing plate in which a reflecting plate or a semi-transmissive reflecting plate is laminated on the polarizing plate, an elliptical polarizing plate or circular polarizing plate in which a retardation plate is further laminated on the polarizing plate, or a brightness enhancing film is further laminated Polarizing plates are preferred.

The reflective polarizer is formed by forming a reflective layer on the polarizer, and is used to form a liquid crystal display device of a type that reflects and displays incident light from the viewing side (display side). This is advantageous in that the display device can be thinner. Formation of a reflective polarizing plate can be performed by a suitable method, such as the method of laying a reflective layer which consists of metal etc. on the single side | surface of a polarizing plate through a transparent protective layer as needed.

As a specific example of a reflective polarizing plate, what provided the reflective layer by laying the foil and vapor deposition film which consist of reflective metals, such as aluminum, on the single side | surface of the transparent protective film which carried out the mat process as needed. Moreover, what contains microparticles | fine-particles in the said transparent protective film to make surface fine concavo-convex structure, and has a reflective layer of a fine concavo-convex structure on it, etc. are mentioned. The above-described reflective layer of the fine concavo-convex structure has an advantage of preventing incident light from being diffused by diffused reflection to prevent directivity and glare (glare) and to suppress light and light unevenness. Moreover, the protective film containing microparticles | fine-particles also has the advantage of being able to spread | diffuse when incident light and the reflected light transmit it, and to suppress a light and shade nonuniformity further. Formation of the reflective layer of the finely uneven structure reflecting the surface finely uneven structure of the transparent protective film, for example, by applying a metal to the surface of the transparent protective layer in a suitable manner such as vacuum deposition method, ion plating method, sputtering method or plating method It can carry out by the method of laying directly.

Instead of the method of directly applying to the transparent protective film of the polarizing plate, the reflecting plate may be used as a reflecting sheet or the like formed by forming a reflecting layer on a suitable film according to the transparent film. In addition, since the reflective layer is usually made of a metal, the use form in the state where the reflective surface is covered with a transparent protective film, a polarizing plate, or the like can prevent the reduction of the reflectance by oxidation, and furthermore, the viewpoint of long-term sustaining of the initial reflectance or the protective layer. It is more preferable from a viewpoint that separate laying can be avoided.

In addition, a semi-transmissive polarizing plate can be obtained by making it into the semi-transmissive reflective layer, such as the half mirror which reflects light and permeate | transmits in a reflection layer in the above. The semi-transmissive polarizing plate is usually formed on the back side of the liquid crystal cell, and when using a liquid crystal display device or the like in a relatively bright atmosphere, reflects incident light from the viewing side (display side) to display an image. A liquid crystal display of the type which displays an image, etc. can be formed using built-in light sources, such as a backlight built in the backside of a polarizing plate. That is, the transflective polarizing plate can save energy used by light sources such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of the type that can be used using a built-in light source even in a relatively dark atmosphere.

An elliptical polarizing plate or circular polarizing plate in which a retardation plate is further laminated on the polarizing plate will be described. A retardation plate or the like is used to change linearly polarized light into elliptical polarization or circularly polarized light, to change elliptical polarization or circularly polarized light into linearly polarized light, or to change the polarization direction of linearly polarized light. In particular, a so-called quarter wave plate (also referred to as λ / 4 plate) is used as the phase difference plate which changes linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light. A half wave plate (also called a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

The elliptical polarizing plate is effectively used for compensating (preventing) the coloration (blue or yellow color) caused by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device and for displaying in black and white without coloration. In addition, controlling the three-dimensional refractive index is preferable because it can compensate (prevent) the coloration generated when the screen of the liquid crystal display device is viewed in the oblique direction. The circular polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflection type liquid crystal display device in which an image becomes color display, and also has a function of antireflection.

As a retardation plate, the birefringent film formed by carrying out uniaxial or biaxial stretching process of a polymeric material, the orientation film of a liquid crystal polymer, the thing which supported the orientation layer of a liquid crystal polymer with a film, etc. are mentioned. Although the thickness of a retardation plate is not specifically limited, either, About 20-150 micrometers is common.

Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethylvinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyallylate, poly Sulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyphenylene sulfide, polyphenylene oxide, polyallyl sulfone, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, norbornene-based resin, or These binary and ternary various copolymers, graft copolymers, blends, etc. are mentioned. These polymeric raw materials become an orientation substance (stretched film) by extending | stretching etc.

Examples of the liquid crystal polymer include various main chain and side chains in which a conjugated linear atomic group (mesogen) for imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. Specific examples of the main chain type liquid crystal polymer include, for example, a nematic oriented polyester liquid crystal polymer, a discotic polymer, a cholesteric polymer, or the like having a structure in which a mesogenic group is bonded by a spacer portion to impart flexibility. Can be. As a specific example of a side chain type liquid crystal polymer, the para substituted cyclic type of a nematic orientation imparting property is provided through the spacer part which consists of polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain frame | skeleton, and consists of a conjugated atomic group as a side chain. The thing which has the mesogenic part which consists of a compound unit, etc. are mentioned. These liquid crystal polymers are, for example, a solution of a liquid crystalline polymer on an alignment treatment surface such as rubbing a surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or depositing silicon oxide on all sides. It is carried out by expanding the heat treatment.

The retardation plate may have a suitable retardation according to the purpose of use, for example, for the purpose of compensating coloring or vision due to birefringence of various wavelength plates and liquid crystal layers, or by laminating two or more kinds of retardation plates. The thing which controlled optical characteristics, such as these, may be sufficient.

In addition, said elliptical polarizing plate and reflective elliptic polarizing plate laminate | stack a polarizing plate or a reflective polarizing plate, and a phase difference plate by a suitable combination. Such elliptical polarizing plates and the like can also be formed by sequentially laminating them separately in the manufacturing process of the liquid crystal display device so as to be a combination of the (reflective) polarizing plate and the retardation plate. It is excellent in the stability of quality, lamination | stacking workability, etc., and there exists an advantage which can improve manufacturing efficiency, such as a liquid crystal display device.

The polarizing plate which affixed the polarizing plate and a brightness improving film is normally formed in the back side of a liquid crystal cell, and is used. The brightness enhancement film exhibits a property of reflecting linearly polarized light on a predetermined polarization axis or circularly polarized light in a predetermined direction when natural light is incident due to a back light or reflection from a backside of a liquid crystal display device or the like, and transmitting other light. The polarizing plate laminated | stacked with a polarizing plate is made to inject light from light sources, such as a backlight, and acquire the transmitted light of a predetermined polarization state, and is reflected, without transmitting the light other than the said predetermined polarization state. The light reflected from the surface of the brightness enhancing film is inverted again through a reflective layer or the like formed on the rear surface side thereof, and reentered into the brightness enhancing film, and part or all of the light is transmitted as light in a predetermined polarization state, The brightness can be improved by increasing the amount of light and increasing the amount of light that can be used for liquid crystal display image display by supplying polarized light that is hardly absorbed by the polarizer. That is, when light enters through a polarizer from the back side of a liquid crystal cell by a backlight etc. without using a brightness improving film, the light which has a polarization direction which does not correspond to the polarization axis of a polarizer is mostly absorbed by a polarizer, and a polarizer Does not penetrate. That is, although it depends also on the characteristic of the polarizer used, about 50% of light is absorbed by a polarizer, and the quantity of light which can be used for a liquid crystal image display etc. decreases by that amount, and an image becomes dark. The brightness enhancement film repeatedly reflects the light having the polarization direction absorbed by the polarizer in the brightness enhancement film without incident to the polarizer, inverts it through a reflective layer formed on the back side thereof, and reenters the brightness enhancement film. Since only the polarization of the polarization direction in which the polarization direction of the light reflected and inverted between the two passes through the polarizer is transmitted by the brightness enhancement film, the light is transmitted to the polarizer so that light such as a backlight can be efficiently displayed on the image of the liquid crystal display device. It can be used to lighten the screen.

A diffuser plate may be provided between the brightness enhancing film and the reflective layer. The light in the polarization state reflected by the brightness enhancing film is directed toward the reflective layer or the like, but the diffuser plate provided uniformly diffuses the light passing therethrough and at the same time resolves the polarization state to become a non-polarization state. In other words, the light in the natural light state is directed toward the reflective layer or the like, is repeatedly passed through the diffuser plate and reincident to the brightness enhancing film. Thus, by providing a diffuser plate for returning the polarized light to the original natural light between the brightness enhancement film and the reflective layer, the brightness of the display screen can be maintained while the brightness unevenness of the display screen can be reduced to provide a uniform and bright screen. Can be. By providing such a diffuser plate, it is considered that the first incident light can increase the number of times of reflection repetition moderately and can be combined with the diffuser function of the diffuser plate to provide a uniform and bright display screen.

As the brightness enhancement film, for example, a cholesteric liquid crystal having a characteristic of transmitting a linear polarization of a predetermined polarization axis and reflecting other light, such as a multilayer laminate of a dielectric or a multilayer laminate of a thin film of different refractive index anisotropy. Suitable ones, such as those exhibiting characteristics of reflecting either circularly polarized light and transmitting other light, such as left linearity or preferential rotation, such as supporting the alignment film of the polymer or the alignment liquid crystal layer on the film substrate, can be used. .

Therefore, in the luminance improvement film of the type which permeate | transmits linearly polarized light of the said predetermined polarization axis, it can transmit efficiently, restraining the absorption loss by a polarizing plate by making the transmitted light into a polarizing plate uniformly and injecting it as it is. On the other hand, in the luminance-enhancing film of the type which transmits circularly polarized light like a cholesteric liquid crystal layer, it can be made to enter a polarizer as it is, but in order to suppress absorption loss, the circularly polarized light linearly polarizes through a phase difference plate, and enters into a polarizing plate. It is preferable to make it. In addition, by using a quarter wave plate as the retardation plate, circularly polarized light can be converted into linearly polarized light.

A retardation plate which functions as a quarter wave plate at a wide wavelength such as visible light is, for example, a phase difference layer exhibiting retardation characteristics different from that of a retardation plate functioning as a quarter wave plate with respect to pale light having a wavelength of 550 nm, for example. For example, it can obtain by the method of superimposing the retardation layer which functions as a 1/2 wave plate. Therefore, the phase difference plate arrange | positioned between a polarizing plate and a brightness improving film should just consist of one layer or two or more phase difference layers.

In addition, also in the cholesteric liquid crystal layer, by using a combination of different reflection wavelengths, a layered structure in which two or three or more layers are overlapped can reflect circularly polarized light in a wide wavelength range such as visible light. Based on this, transmission circularly polarized light in a wide wavelength range can be obtained.

In addition, the polarizing plate may laminate | stack a polarizing plate and two or three or more optical layers like the said polarization split type polarizing plate. Therefore, it may be a reflective elliptically polarizing plate, a semi-transmissive elliptically polarizing plate, etc. which combined the said reflective polarizing plate, a transflective polarizing plate, and a phase difference plate.

Although the optical film which laminated | stacked the said optical layer on the polarizing plate can also be formed by the method of separately laminating | stacking sequentially in manufacturing processes, such as a liquid crystal display device, what laminated | stacked previously was made into the optical film, such as stability of quality, assembly workability, etc. It is excellent in this and there exists an advantage which can improve manufacturing processes, such as a liquid crystal display device. Suitable lamination means, such as an adhesion layer, can be used for lamination. At the time of adhering the polarizing plate and the other optical layer, these optical axes can be set to an appropriate placement angle in accordance with a desired phase difference characteristic or the like.

Moreover, in each layer, such as an optical film and an adhesive layer of the adhesive optical film of this invention, a salicylic acid ester type compound, a benzophenol type compound, a benzotriazole type compound, a cyanoacrylate type compound, and a nickel complex salt type system are mentioned, for example. The thing which provided the ultraviolet absorbing power by methods, such as a process with a ultraviolet absorber, such as a compound, may be sufficient.

The adhesive optical film of this invention can be used suitably for formation of various image display apparatuses, such as a liquid crystal display device. Formation of a liquid crystal display device can be performed according to the prior art. That is, a liquid crystal display device is generally formed by appropriately assembling a component part, such as a liquid crystal cell, an adhesive optical film, and an illumination system as needed, and attaching a drive circuit, etc. In this invention, adhesion by this invention is carried out. There is no limitation in particular except the point which uses a type | mold optical film, and it can follow conventionally. Also about a liquid crystal cell, arbitrary types, such as a TN type, STN type, (pi) type, can be used, for example.

Suitable liquid crystal display devices, such as the liquid crystal display device which arrange | positioned the adhesive optical film on the one side or both sides of a liquid crystal cell, and the thing which used the backlight or the reflecting plate for the illumination system, can be formed. In that case, the optical film by this invention can be provided in the one side or both sides of a liquid crystal cell. When providing an optical film in both sides, they may be the same or may differ. At the time of formation of the liquid crystal display device, for example, a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, a backlight, or the like and a suitable component at a suitable position may be one layer or two. It can be arranged in layers or more.

Next, an organic electroluminescent device (organic EL display device) will be described. The optical film (polarizing plate etc.) of this invention can be applied also in an organic electroluminescence display. In general, an organic EL display device forms a light emitting body (organic electroluminescent light emitting body) by sequentially stacking a transparent electrode, an organic light emitting layer, and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various organic thin films, for example, a hole injection layer made of a triphenylamine derivative or the like and a laminate of a light emitting layer made of a fluorescent organic solid such as anthracene, or such a light emitting layer and a perylene derivative. The structure which has various combinations, such as the laminated body of the electron injection layer which consists of these, or such a hole injection layer, a light emitting layer, and an electron injection layer, is known.

In the organic EL display device, holes and electrons are injected into the organic emission layer by applying a voltage to the transparent electrode and the metal electrode, and energy generated by the recombination of the holes and the electrons excites the fluorescent material, and the excited fluorescent material is in a ground state. It emits light by the principle of emitting light when returning to. The mechanism of intermediate recombination is the same as that of a general diode, and as can be expected from this point, the current and the emission intensity exhibit strong nonlinearity with commutation with respect to the applied voltage.

In the organic EL display device, at least one electrode must be transparent in order to extract light emitted from the organic light emitting layer, and a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is usually used as an anode. On the other hand, in order to easily inject electrons and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and metal electrodes such as Mg-Ag and Al-Li are usually used.

In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer also transmits light almost completely like the transparent electrode. As a result, the light incident on the surface of the transparent substrate at the time of non-luminescence, and transmitted through the transparent electrode and the organic light emitting layer and reflected by the metal electrode again goes out to the surface side of the transparent substrate, so that the display of the organic EL display device when viewed from the outside The surface looks like a mirror.

An organic EL display device comprising an organic electroluminescent light-emitting body comprising a transparent electrode on the front side of an organic light emitting layer that emits light by application of a voltage and a metal electrode on the back side of the organic light emitting layer, wherein the organic EL display device is transparent. While providing a polarizing plate on the surface side of an electrode, a phase difference plate can be provided between these transparent electrodes and a polarizing plate.

Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action. In particular, when the phase difference plate is constituted by a quarter wave plate, and the angle between the polarization direction of the polarizing plate and the phase difference plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded.

That is, only the linearly polarized light component transmits external light incident on the organic EL display device by the polarizing plate. This linearly polarized light is generally elliptically polarized by the retardation plate. Particularly, the linearly polarized light becomes circularly polarized light when the retardation plate is a quarter wave plate and the angle between the polarization direction of the polarizing plate and the retardation plate is? / 4.

The circularly polarized light is transmitted through the transparent substrate, the transparent electrode, and the organic thin film, and is reflected by the metal electrode, and then again passes through the organic thin film, the transparent electrode, and the transparent substrate, and becomes linearly polarized again in the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot pass through a polarizing plate. As a result, the mirror surface of a metal electrode can be shielded completely.

Example

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples. In addition, all the parts and% in each case are a basis of weight.

<Optical film>

A wide view (WV) film manufactured by Fuji Photo Film Co., Ltd. was used. The WV film had the discotic liquid crystal layer in which the discotic liquid crystal molecule was diagonally aligned on the cellulose polymer film which is a transparent base film.

Moreover, the WV film was isolate | separated from the diagonal alignment layer of the discotic liquid crystal molecule, and the characteristic in (lambda) = 590 nm was measured by KOBRA-21ADH by the Oji measurement instrument company. The refractive index of the direction orthogonal to the direction which has the largest refractive index of nx and in-plane maximum refractive index in surface was made into ny and the refractive index of the thickness direction was set to nz. The thickness was d. The transparent support was (DELTA) nd = (nx-ny) xd = 12nm, Rth = (nx-nz) xd = 100nm. On the other hand, the inclination alignment layer was Δnd = 30 nm, Rth = 150 nm, and the average inclination angle θ = 17 ° as a result of measuring the phase difference by changing the incident angle from -50 ° to 50 ° in the direction in which the optical axis was inclined.

After the saponification process of the transparent base film side of the said WV film, the saponification process surface and the polyvinyl alcohol-type polarizer (Nitto Electric Co., Ltd. product, SEG-5424WL) were attached with the polyvinyl alcohol-type adhesive agent. On the other hand, on the other side of a polarizer, a transparent protective film (triacetylcellulose film, thickness 80micrometer) is affixed with the same polyvinyl alcohol-type adhesive agent, and the optical film which has a polarizing plate (polarizing plate with a viewing angle expansion film) is manufactured. It was.

<Sublayer>

The undercoat agent which adjusted acrylic acid ester (the Nippon Catalyst Co., Ltd. product, polyimide NK380) to toluene so that solid content might be 2% was used.

<Adhesive layer>

As a base polymer, the solution (solid content 30%) containing the weight average molecular weight 2 million acrylic polymer which consists of a copolymer of butylacrylate: acrylic acid: 2-hydroxyethyl acrylate = 100: 5: 0.1 (weight ratio) was used. . In the acrylic polymer solution, 4 parts of Nippon Polyurethane Colonate L, an isocyanate-based polyfunctional compound, based on 100 parts of polymer solids, and 0.5 part of additive (Shin-Etsu Silicone, KBM403), solvent for viscosity adjustment (ethyl acetate ) Was added to prepare a pressure-sensitive adhesive solution (solid content 12%). The pressure-sensitive adhesive solution was applied onto a release sheet (polyethylene terephthalate substrate: diamond foil MRF38, manufactured by Mitsubishi Chemical Polyester) so that the thickness after drying was 25 μm, and then dried by a hot air circulation oven to form an adhesive layer. It was.

Example 1

(Investigation processing)

Ultraviolet light was irradiated to the discotic liquid crystal layer of the optical film which has the said polarizing plate using the ultraviolet irradiation device (UVUN-made by CSUN, UVC-321AM) (roughness 40mW / cm <2>, accumulated light quantity 300mJ / cm <2>). This ultraviolet irradiation was performed 10 times (3000mJ / cm <2> of accumulated light quantity). The accumulated light amount is the accumulated light amount at a wavelength of 350 nm.

(Production of Adhesive Optical Film)

After applying a primer to the surface of the discotic liquid crystal layer subjected to the irradiation treatment to form a primer layer (thickness 20 nm), a release sheet having an adhesive layer was adhered to prepare an adhesive optical film. It was.

Comparative Example 1

In Example 1, the adhesive optical film was manufactured in the same manner as in Example 1 except that the irradiation treatment was not performed.

About the discotic liquid crystal layer before and behind the said irradiation process, the following evaluation was performed about the obtained adhesive optical film. The results are shown in Table 1.

<Hardness>

The surface hardness of the discotic liquid crystal layer was measured by the following apparatus.

Analytical device: Nano Indenter (manufactured by MTS, SA2)

Indenter: Triangular diamond indenter

The diamond indenter is pushed from the discotic liquid crystal layer side, and the hardness is measured from the stress applied to the indenter at that time. The hardness at the indentation depth of 100 nm is measured. The measurement was performed 10 times and these average values are described.

<Polymerizable unsaturated group: absorbance ratio>

The polymerizable unsaturated group remaining in the discotic liquid crystal layer was measured by the following apparatus.

Analytical device: FT-IR (manufactured by Thermo Nicolet, Magna750)

Measurement method: ATR method

IR decision: ZnSe

Incident angle: 45 °

Measurement Wavelength: 4000 ~ 650cm ^-1

Cumulative recovery: 128 times

Detector: DTGS

IR spectrum obtained of the ^1510cm-1 (aromatic-derived) and 811cm ^-1 - absorbance ratio (811cm ^-1 / 1510cm ^-1) of the (carbon-carbon double bond derived) was calculated.

<Stain>

It arrange | positioned on the backlight so that the adhesive layer side of the obtained adhesive optical film (size: 300 mm x 220 mm) may become an upper side. The backlight was turned on in the atmosphere of 80 degreeC, and the following reference | standard evaluated whether the window frame unevenness generate | occur | produced in the periphery part (within 10 mm from an edge) of an optical film. The lighting time was confirmed about 100 hours, 170 hours, and 340 hours.

○: no stain on the periphery

×: stain on the periphery

The present inventors think that the discotic liquid crystal layer functioning as an optical compensation layer is formed by the orientation and curing of a discotic liquid crystal compound having a polymerizable unsaturated group, but the polymerizable unsaturated group remains in the discotic liquid crystal layer. By the influence of the said residual polymerizable unsaturated group, when the lighting state of a backlight became prolonged, it was thought that the front retardation value might become larger than the center part in a window frame part, and this may be a cause of window frame unevenness.

Therefore, in the manufacturing method of the adhesive optical film of this invention, before forming an adhesive layer in the discotic liquid crystal layer formed in the single side | surface of a transparent base film, discotic light is irradiated to a discotic liquid crystal layer by ultraviolet-ray and / or visible light. The polymerizable unsaturated group remaining in the liquid crystal layer was reduced. Thereby, by suppressing the influence by the polymerizable unsaturated group which remain | survives in a discotic liquid crystal layer, window frame unevenness resulting from large front phase difference value in a window frame part can be suppressed. Moreover, it is thought that the hardness of the surface of a discotic liquid crystal layer becomes high by irradiating an ultraviolet light and / or visible light to a discotic liquid crystal layer, and there exists an effect which suppresses window frame unevenness by such an improvement of surface hardness.

Since window frame unevenness is easy to generate | occur | produce when a liquid crystal display device is large, the manufacturing method of the adhesive optical film of this invention is especially effective at the time of manufacturing the adhesive optical film with large size. Moreover, since window frame unevenness is easy to generate | occur | produce when environmental temperature is high, the manufacturing method of the adhesive optical film of this invention is especially effective when manufacturing the adhesive optical film used in high temperature environment.

Claims (8)

Adhesive type optical which has the process of forming an adhesive layer in the said discotic liquid crystal layer of the optical film which has the discotic liquid crystal layer formed by the orientation and hardening of the discotic liquid crystal compound which has a polymerizable unsaturated group on the single side | surface of a transparent base film. As a manufacturing method of a film, Ultraviolet light and / or visible light are irradiated to a discotic liquid crystal layer before the process of forming an adhesive layer, The manufacturing method of the adhesive optical film characterized by the above-mentioned. The method of claim 1, A method for producing a pressure-sensitive adhesive optical film, comprising a step of forming an undercoat layer after irradiating ultraviolet light and / or visible light and before performing a step of forming an adhesive layer. The method of claim 1, Irradiation light contains ultraviolet light and the accumulated light amount in wavelength 350nm is 10-10000mJ / cm <2>, The manufacturing method of the adhesive optical film characterized by the above-mentioned. The method of claim 1, The single side | surface of the transparent base film in which a discotic liquid crystal layer is formed is a rubbing process, or the orientation film is formed, The manufacturing method of the adhesive optical film characterized by the above-mentioned. The method of claim 1, The optical film has the polarizer laminated on the single side | surface of the transparent base film of the side in which the discotic liquid crystal layer is not formed, The manufacturing method of the adhesive optical film characterized by the above-mentioned. The method of claim 1, After performing the process of forming an adhesive layer, it has a process of laminating | stacking a polarizer on the single side | surface of the transparent base film of the side in which the discotic liquid crystal layer is not formed, The manufacturing method of the adhesive optical film characterized by the above-mentioned. The adhesive optical film obtained by the manufacturing method in any one of Claims 1-6. An image display device using at least one adhesive optical film according to claim 7.

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