JP2011232546A - Optical laminate, polarizing plate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical laminate having superior manufacturing stability, which is superior in anti-glare and black tone in a bright room and equipped with an antidazzling function with good balance, and also to provide a polarizing plate and a display device.SOLUTION: The optical laminate is formed by laminating optical functional layers 15, 16 on a translucent base body 20. On at least one surface of the optical functional layer, irregular shapes are formed, and the arithmetic mean height (Ra) on the optical functional surfaces having the irregular shapes is 0.040 or more and less than 0.200. The distribution ratio of an inclination angle of 0.2 degrees or less occupied in the distribution of the inclination angles of the optical functional surfaces having the irregular shapes is 30% or more and 95% or less.

Description

The present invention relates to an optical laminate, a polarizing plate, and a display device.
The optical laminate of the present invention is provided on the surface of a display such as a liquid crystal display (LCD), a plasma display (PDP), or an organic electroluminescence (OLED), used as a component of a display, or an organic EL that constitutes an OLED. In order to improve the efficiency of extracting the light generated in the layer out of the organic EL, it can be preferably used on the observation surface side. In particular, the present invention relates to an optical laminate that can be suitably used for, for example, a television display, which places importance on visibility such as antiglare properties, blackness in a bright room, and dark room contrast.

Display devices such as liquid crystal displays (LCDs) and plasma displays (PDPs) are capable of visually recognizing images by reflecting indoor lighting such as fluorescent lamps, sunlight from windows, and operator shadows on the display surface. Sex is disturbed. Therefore, on these display surfaces, in order to improve the visibility of the image, the surface reflected light can be diffused, regular reflection of external light can be suppressed, and reflection of the external environment can be prevented (has antiglare properties). ) A functional film such as an optical laminate having a fine relief structure is provided on the outermost surface.

These functional films include an optical functional layer in which a fine concavo-convex structure is formed on a translucent substrate such as polyethylene terephthalate (hereinafter referred to as “PET”) or triacetyl cellulose (hereinafter referred to as “TAC”). Those provided and those obtained by laminating a low refractive index layer on a light diffusing layer are generally produced and sold, and development of a functional film that provides a desired function by a combination of layer configurations is in progress.

When the optical layered body is used on the outermost surface of the display, there is a problem in that when used in a bright room, a black display image becomes whitish due to light diffusion and the contrast is lowered. For this reason, there is a demand for an optical laminate that can achieve high contrast even when antiglare properties are reduced (high contrast AG). As a method for improving the contrast of the optical layered body, for example, the surface irregularity shape is optimized.
As a method for forming a concavo-convex shape on the surface of the optical functional layer, the optical functional layer forming material is coated with a coating material for forming an optical functional layer to which fine particles are added, and then the optical functional layer forming material is irradiated with ultraviolet rays. In general, an optical functional layer is formed (see, for example, Patent Document 1).
There is also a method for achieving both antiglare properties and contrast by optimizing the particle size and surface irregularity shape (tilt angle) of the fine particles contained in the optical functional layer (see, for example, Patent Document 2).
Also, by using a plurality of resin components, surface irregularities are formed without containing fine particles, and a string-like structure is formed by using the phase separation characteristics of the resin components to achieve both antiglare properties and contrast. (For example, refer to Patent Document 3).

JP 2002-196117 A JP 2008-158536 A JP 2008-225195 A

As in Patent Document 1, when an optical functional layer containing fine particles is used, an antiglare property and an antiglare effect are exhibited. However, there is a problem that it is difficult to achieve high contrast because light scattering occurs at the interface between the fine particles contained in the optical functional layer and the surface irregularities of the optical functional layer based on the shape of the fine particles.
As in Patent Document 2, even when the particle diameter of the fine particles and the inclination angle of the surface irregularities are optimized, there is a problem that the contrast is insufficient.
As in Patent Document 3, there is a problem in manufacturing stability with respect to a method of forming a string-like convex portion on the surface using phase separation of a plurality of resin components.

Accordingly, an object of the present invention is to provide an optical laminate, a polarizing plate, and a display device that have excellent anti-glare properties, darkness in a bright room, and well-balanced anti-glare functions, and excellent manufacturing stability. To do.
In addition to the above-described antiglare property, blackness in a bright room, and glare prevention function, it is a subordinate issue to provide an optical laminate that can achieve higher darkroom contrast.
In addition, it is a subordinate subject to provide an optical laminated body that is economically excellent by achieving these functions even in a configuration in which one optical functional layer is laminated on a translucent substrate.

In the present invention, the light-transmitting organic fine particles contained in the optical functional layer are unevenly distributed, so that the smooth portion occupying the surface unevenness, that is, the convex portion having an appropriate height while including more uneven portions having a low inclination angle than in the past It has been found that there is a region where all the functions of antiglare property, darkness of bright room, and glare prevention are optimized.

The present invention has solved the above problems by the following technical configuration.

(1) An optical laminate in which an optical functional layer is laminated on a translucent substrate, wherein an uneven shape is formed on at least one surface of the optical functional layer, and the optical functional layer surface having the uneven shape The arithmetic average height (Ra) is 0.040 or more and less than 0.200, and the proportion of the inclination angle distribution of 0.2 degrees or less in the inclination angle distribution of the optical functional layer surface having the concavo-convex shape is 30% or more and 95. % Or less of an optical laminate.
(2) The optical layered body according to (1), wherein the optical functional layer is composed of one or more optical functional layers mainly composed of a radiation curable resin composition.
(3) The optical layered body according to (1), wherein the optical functional layer contains at least a radiation curable resin composition and translucent fine particles.
(4) The optical layered body according to (3), wherein the translucent fine particles have an average particle size of 0.3 to 7.0 μm.
(5) The optical layered body according to (1), wherein the thickness of the optical functional layer is larger than the average particle diameter of the translucent fine particles.
(6) A polarizing plate comprising a polarizing substrate laminated on a translucent substrate constituting the optical laminate according to any one of (1) to (5).
(7) A display device comprising the optical laminate according to any one of (1) to (5).

ADVANTAGE OF THE INVENTION According to this invention, it can provide the optical laminated body, polarizing plate, and display apparatus which are excellent in anti-glare property and the blackness in a bright room, are provided with the function of glare prevention in a well-balanced, and are excellent in manufacturing stability.
In addition to the antiglare property, the blackness in a bright room, and the function of preventing glare, it is possible to provide an optical laminate that can achieve higher dark room contrast.
In addition, even in a configuration in which one optical functional layer is laminated on a light-transmitting substrate, by achieving these functions, an economically excellent optical laminated body can be provided.
The optical laminate, polarizing plate and display device of the present invention can be preferably used for large TV applications.

It is the schematic diagram showing the structure of an optical functional layer, Comprising: (a) Plan view of sea-island structure, (b) Plan view of random aggregation structure, (c) Cross-sectional side view of sea-island structure, (d) Random aggregation structure It is a cross-sectional side view. It is the SEM photograph image | photographed, after carbon-depositing the structure of the optical function layer surface in Example 5. FIG. It is the SEM photograph image | photographed, after carbon-depositing the cross section of the optical laminated body in Example 5. FIG. It is the photograph which mapped the structure of the surface of the optical function layer in Example 5 by the inorganic component (Si) by EDS. It is the SEM photograph image | photographed, after carbon-depositing the structure of the optical function layer surface in the comparative example 3. FIG. It is the photograph which mapped the structure of the surface of the optical function layer in the comparative example 3 by the inorganic component (Si) by EDS. It is the SEM photograph image | photographed, after carbon-depositing the sea island structure of the optical function layer surface in the comparative example 5. FIG.

The present invention will be described below.
The optical layered body of the present invention is formed by laminating an optical functional layer on a translucent substrate, and an uneven shape is formed on at least one surface of the optical functional layer so that a predetermined inclination angle is distributed. It is characterized by. The uneven shape may be formed on one side of the optical function layer or may be formed on both sides. The uneven shape is preferably formed on the side opposite to the translucent substrate (hereinafter sometimes simply referred to as “surface” or “surface side”).
The basic structure of the optical layered body according to the present embodiment is that at least one surface of the optical functional layer has a concavo-convex shape in which a predetermined inclination angle is distributed.

The optical functional layer constituting the present invention preferably has a random aggregation structure. By having a random aggregation structure, it becomes easy to form an uneven shape with a predetermined inclination angle distributed on at least one surface of the optical functional layer. FIG. 1 is a diagram schematically showing the structure of the optical functional layer. (A) And (b) is the top view which showed the surface structure of the optical function layer, (c) And (d) is the sectional side view which showed the side sectional structure of the optical laminated body. (A) and (c) are optical functional layers having a conventional sea-island structure, and (b) and (d) are optical functional layers having a random aggregation structure.
Since the optical functional layer having a random aggregation structure may have at least a first phase and a second phase, the optical functional layer may have a third phase or a fourth phase. The number of phases constituting the optical functional layer is not limited. For example, the optical functional layer may have a lamellar structure. Specifically, a structure in which another phase (for example, a third phase) is formed on the unevenness of the optical function layer 16 in FIG.

As shown in FIGS. 1B and 1D, the optical functional layer having a random aggregation structure contains the first phase 1 containing a relatively large amount of the resin component and a relatively small amount of the resin component ( And at least a second phase 2 containing a relatively large amount of inorganic components. The second phase 2 exists in various sizes and shapes. The first phase and the second phase constituting the optical functional layer exist in a three-dimensionally complicated manner.
Further, fine particles 3 are present in the optical functional layer 16 having a random aggregation structure. Around the fine particles 3, the first phase 1 constituting the optical functional layer 16 hardly exists, and the second phase 2 exists. That is, the second phase 2 is unevenly distributed around the fine particles 3 constituting the optical function layer 16. The uneven distribution of the second phase 2 around the fine particles 3 can be confirmed by using a laser microscope, SEM (scanning electron microscope), EDS (energy dispersive X-ray spectrometer) or the like.

In the present invention, whether “the second phase is unevenly distributed around the fine particles” is determined based on the SEM result viewed from the optical functional layer surface of the optical laminate. First, arbitrary 10 fine particles are selected from the SEM result. Next, from the center of each fine particle, the proportion of the second phase in the first phase and the second phase existing in a concentric circle having a size 10 times the major axis of the fine particle is determined. Subsequently, the average value of the proportion of the second phase in any 10 concentric circles is calculated. If the average value is relatively high compared to the comparative control, it corresponds to “the second phase is unevenly distributed around the fine particles”, and if the average value is relatively low compared to the comparative control, This does not correspond to “the second phase is unevenly distributed around the fine particles”.
The comparison control is obtained from the SEM result. The comparative control is made to correspond to a concentric circle having a size 10 times as large as the major axis of each of the fine particles, centered on a point having ten points existing in the first phase. However, all the 10 points are provided in locations that do not contain fine particles in the concentric circles. In this way, the average value of the proportion of the second phase in the concentric circles of the 10 points is calculated.

In the present invention, in the optical functional layer, the first phase and the second phase are three-dimensionally intermingled with each other, and a unique structure in which the second phase is unevenly distributed around the fine particles is randomly aggregated structure. That's it.
Conventionally, as shown in FIG. 1C, the optical functional layer 15 has surface irregularities formed on the translucent substrate 20 using the shape of the fine particles 30 and 31. That is, the resin 40 present on the fine particles 30 and 31 rises based on the shape of the fine particles, and the resin 40 does not rise in the portions where the fine particles 30 and 31 do not exist, so that convex portions and concave portions are alternately formed. Therefore, the surface unevenness of the optical function layer 15 has a large inclination. In FIGS. 1A and 1C, even when a plurality of fine particles gather to form surface irregularities, the surface irregularities have a large inclination.
On the other hand, since the second phase 2 is unevenly distributed around the fine particles 3 in the optical functional layer 16 having a random aggregation structure, the optical functional layer 16 is finer than the conventional optical functional layer shown in FIGS. Unevenness can be reduced, and high antiglare properties and darkness in a bright room can be improved. This is because the optical functional layer having a random aggregation structure forms a relatively flat surface on the first phase, so that the blackness under the bright room is improved and the high darkroom contrast in the first phase. This is because the convex portion is formed by the fine particles taken into the second phase and the antiglare action is exerted by the fine particles taken into the second phase. That is, it becomes easy to form an uneven shape with a predetermined inclination angle distributed on at least one surface of the optical functional layer.
In addition, when the second phase is not unevenly distributed around the fine particles and the fine particles are present in the first phase and the second phase, irregularities are formed in various portions of the optical functional layer (the number of irregularities is large). Therefore, the optical functional layer becomes whitish, which is not preferable. In addition, an optical functional layer that does not contain fine particles is not preferable because it is difficult to control the number and height of surface irregularities, making it difficult to manufacture.
The optical functional layer constituting the present invention is preferable as long as it has a random aggregation structure as a main structure, but for example, another structure (for example, a sea-island structure) may partially exist.

When gold is deposited on the random aggregated structure and then observed with an electron microscope, it can be seen that the fine particles contained in the optical functional layer form convex portions having surface irregularities.
Moreover, after performing carbon vapor deposition on a random aggregated structure, the state of element distribution on the carbon vapor deposition surface can be roughly confirmed by observing with an electron microscope. This means that there are multiple elements on the carbon deposition surface. For example, the element with a large atomic number is displayed in white, and the element with a small atomic number is displayed in black. It depends on what you can do.
Furthermore, by performing mapping by EDS on the optical functional layer having a random aggregation structure, it is possible to confirm the elements present on the surface of the coating film (optical functional layer) and the cross section of the coating film (optical functional layer). it can. This mapping by EDS can color-display a place where a lot of specific elements (for example, carbon atoms, oxygen atoms, silicon atoms, etc.) are distributed.
By using the above-mentioned electron microscope observation and mapping by EDS, it is possible to confirm the uneven structure of the random aggregate structure and the distribution of the specific element. Thereby, for example, it can be confirmed that many specific elements are distributed in the convex portions of the surface irregularities.

A more specific description will be given with reference to FIGS. 2 and 4 are diagrams in which the surface state of the optical functional layer prepared in Example 1 described later is photographed in the same field of view, and the optical functional layer is composed of a resin component and an inorganic component.
FIG. 2 is an SEM photograph in which carbon is deposited on the surface of the optical functional layer. The image displayed in the backscattered electron detector represents the backscattered electrons resulting from the components contained on the optical functional layer surface as an image.
The backscattered electrons depend on the atomic number, and can be displayed in different colors, for example, displaying a large atomic number in white and a small atomic weight in black. As shown in FIG. 2, each element in the optical functional layer does not exist uniformly in the horizontal direction of the surface, but a portion having a relatively large content of an element having a large atomic number and a portion having a relatively small content It is made up of.
FIG. 4 shows the mapping result of the inorganic component (Si) by EDS on the surface of the optical functional layer, and the amount of the Si component contained is shown by color shading. As shown in FIG. 4, the Si component also consists of a portion with a relatively high content and a portion with a relatively low content. In FIG. 4, the mapping result of silica (Si) is shown for specific illustration, but the mapping result of other inorganic component elements and resin (organic substance) components can also be shown. In the mapping result shown in FIG. 4, although it depends on detection conditions, it can be detected if the concentration of inorganic components such as silica is 0.2% by mass. That is, in the optical functional layer composed of two phases, the first phase and the second phase, the first phase is composed of 90% by mass or more of a resin component and an inorganic component, and the second phase is 99.8. It comprises a resin component of less than mass% and an inorganic component of 0.2 mass% or more. The resin component contained in the first phase is preferably 95% by mass or more, and more preferably 99% by mass or more. The inorganic component contained in the second phase is preferably 1% or more, more preferably 5% or more, and particularly preferably 10% or more. The resin component contained in the second phase is preferably less than 99%, more preferably less than 95%, and particularly preferably less than 90%. The amount of the inorganic component contained in the optical functional layer is greater in the second phase than in the first phase.
In the portion where the content of the resin component is relatively large (the portion where the color in FIG. 2 is dark), the content of components other than the resin component is relatively small (first phase).
On the other hand, in the portion where the content of the resin component is relatively small (the light-colored portion in FIG. 2), the content of components other than the resin component is relatively large (second phase).
That is, the optical functional layer having a random aggregation structure has a first phase and a second phase intricately present, and has a complementary relationship such that when one component decreases, the other component increases. Is.
2 and 4 show the content of each component in the horizontal direction of the surface of the optical functional layer, but show the content of each component in the vertical direction (thickness direction) of the optical functional layer. Even in the case of the case, a result showing a complementary relationship is obtained (FIG. 3).

<Method for forming a random aggregated structure>
The random aggregate structure can be produced by utilizing a phenomenon in which aggregates of inorganic components are randomly distributed around the fine particles due to convection during solvent volatilization. Specifically, a solution containing a resin component, an inorganic component, fine particles, and a solvent (first solvent and second solvent) is applied onto a light-transmitting substrate, and the solvent (first solvent and second solvent) is added. It can be manufactured through a drying process for generating convection with volatilization and a curing process for curing the dried coating film to form an optical functional layer. More specifically, it can be usually performed by coating the light-transmitting substrate with the solution and evaporating the solvent from the coating layer.
Although the detailed mechanism in the combined use of aggregation and convection has not been elucidated, it can be estimated as follows.
(1) Due to aggregation due to convection during solvent volatilization, first, a convection domain is generated in the coating layer after coating.
(2) Next, aggregation of the inorganic material occurs in each convection domain, and the aggregate becomes larger with time, but the growth of aggregation stops at the domain wall of the convection. With the occurrence of aggregation and time, inorganic components aggregate with the fine particles as nuclei.
(3) As a result, the size of the aggregate is appropriately maintained, and a random aggregate structure is formed by interspersing these in the optical functional layer.
According to the surface asperity associated with the random aggregation structure, it is possible to achieve both antiglare properties, bright room contrast and dark room contrast, which were difficult with the conventional surface asperity due to the sea-island structure.
Hereinafter, materials that can be preferably used for each layer constituting the present invention will be described.

<Translucent substrate>
The translucent substrate according to this embodiment is not particularly limited as long as it is translucent, and glass such as quartz glass and soda glass can also be used. PET, TAC, polyethylene naphthalate (PEN), polymethyl Methacrylate (PMMA), polycarbonate (PC), polyimide (PI), polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), cycloolefin copolymer (COC), norbornene-containing resin, acrylic Various resin films such as resin, polyethersulfone, cellophane, and aromatic polyamide can be suitably used. In addition, when using for PDP and LCD, it is more preferable to use 1 type chosen from a PET film, a TAC film, and a norbornene-containing resin film.

The higher the transparency of these translucent substrates, the better. However, the total light transmittance (JIS K7105) is 80% or more, more preferably 90% or more. Further, the thickness of the translucent substrate is preferably thin from the viewpoint of weight reduction, but considering the productivity and handling properties, the thickness of the translucent substrate is in the range of 1 to 700 μm, preferably 25 to 250 μm. Is preferred.

The surface of the translucent substrate is treated with alkali treatment, corona treatment, plasma treatment, sputtering treatment and other primer treatments, primer coatings such as surfactants and silane coupling agents, and thin film dry coatings such as Si deposition. The adhesion between the optical substrate and the optical functional layer can be improved, and the physical strength and chemical resistance of the optical functional layer can be improved. Also, when another layer is provided between the translucent substrate and the optical functional layer, it is possible to improve the adhesion of each layer interface by the same method as described above, and to improve the physical strength and chemical resistance of the optical functional layer. Can be improved.

<Optical function layer>
The optical functional layer contains a resin component and an inorganic component, and is formed by curing the resin component. The optical functional layer contains fine particles (inorganic fine particles and organic fine particles).

(Resin component)
As the resin component constituting the optical functional layer, a resin having sufficient strength as a cured film and having transparency can be used without particular limitation. Examples of the resin component include a thermosetting resin, a thermoplastic resin, an ionizing radiation curable resin, and a two-component mixed resin. Among these, simple curing can be performed by electron beam or ultraviolet irradiation. An ionizing radiation curable resin that can be efficiently cured by a processing operation is preferable.

Examples of the ionizing radiation curable resin include monomers and oligomers having radical polymerizable functional groups such as acryloyl group, methacryloyl group, acryloyloxy group, and methacryloyloxy group, and cationic polymerizable functional groups such as epoxy group, vinyl ether group, and oxetane group. , Prepolymers, and compositions obtained by mixing polymers alone or as appropriate are used. Examples of monomers include methyl acrylate, methyl methacrylate, methoxy polyethylene methacrylate, cyclohexyl methacrylate, phenoxyethyl methacrylate, ethylene glycol dimethacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, and the like. it can. As oligomers and prepolymers, polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyether acrylate, acrylate compounds such as alkit acrylate, melamine acrylate, silicone acrylate, unsaturated polyester, tetramethylene glycol diglycidyl ether, Epoxy compounds such as propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, bisphenol A diglycidyl ether and various alicyclic epoxies, 3-ethyl-3-hydroxymethyloxetane, 1,4-bis {[((3- Oxeta such as ethyl-3-oxetanyl) methoxy] methyl} benzene, di [1-ethyl (3-oxetanyl)] methyl ether Mention may be made of the compound. Examples of the polymer include polyacrylate, polyurethane acrylate, and polyester acrylate. These can be used alone or in combination.
Among these ionizing radiation curable resins, a polyfunctional monomer having 3 or more functional groups can increase the curing speed and improve the hardness of the cured product. Moreover, the hardness of a hardened | cured material, a softness | flexibility, etc. can be provided by using polyfunctional urethane acrylate.

An ionizing radiation curable fluorinated acrylate can be used as the ionizing radiation curable resin. Ionizing radiation curable fluorinated acrylates are ionizing radiation curable compared to other fluorinated acrylates, resulting in excellent chemical resistance due to cross-linking between molecules and sufficient antifouling even after saponification treatment. The effect of expressing sex is achieved. Examples of the ionizing radiation curable fluorinated acrylate include 2- (perfluorodecyl) ethyl methacrylate, 2- (perfluoro-7-methyloctyl) ethyl methacrylate, 3- (perfluoro-7-methyloctyl) -2- Hydroxypropyl methacrylate, 2- (perfluoro-9-methyldecyl) ethyl methacrylate, 3- (perfluoro-8-methyldecyl) -2-hydroxypropyl methacrylate, 3-perfluorooctyl-2-hydroxylpropyl acrylate, 2- (per Fluorodecyl) ethyl acrylate, 2- (perfluoro-9-methyldecyl) ethyl acrylate, pentadecafluorooctyl (meth) acrylate, unadecafluorohexyl (meth) acrylate, nonafluoropentyl (meth) ) Acrylate, heptafluorobutyl (meth) acrylate, octafluoropentyl (meth) acrylate, pentafluoropropyl (meth) acrylate, trifluoro (meth) acrylate, triisofluoroisopropyl (meth) acrylate, trifluoroethyl (meth) acrylate The following compounds (i) to (xxx) can be used. The following compounds all show the case of acrylate, and any acryloyl group in the formula can be changed to a methacryloyl group.

  These can be used alone or in combination. Of the fluorinated acrylates, a fluorinated alkyl group-containing urethane acrylate having a urethane bond is preferred from the viewpoint of wear resistance, elongation and flexibility of the cured product. Of the fluorinated acrylates, polyfunctional fluorinated acrylates are preferred. Here, the polyfunctional fluorinated acrylate means one having 2 or more (preferably 3 or more, more preferably 4 or more) (meth) acryloyloxy groups.

The ionizing radiation curable resin can be cured by irradiation with an electron beam as it is, but in the case of curing by ultraviolet irradiation, it is necessary to add a photopolymerization initiator. In addition, as a radiation used, any of an ultraviolet-ray, visible light, infrared rays, and an electron beam may be sufficient. Further, these radiations may be polarized or non-polarized.
Photopolymerization initiators include radical polymerization initiators such as acetophenone, benzophenone, thioxanthone, benzoin, and benzoin methyl ether, and cationic polymerization starts such as aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, and metallocene compounds. The agents can be used alone or in appropriate combination.

Moreover, additives, such as a leveling agent and an antistatic agent, can be contained in ionizing radiation curable resin. The leveling agent works to make the tension on the surface of the coating uniform and to repair defects before forming the coating.

  Examples of the leveling agent include silicone leveling agents, fluorine leveling agents, and acrylic leveling agents. The said leveling agent may be used independently and may use 2 or more types together. Among the above leveling agents, from the viewpoint of forming a concavo-convex structure in the optical functional layer, silicone leveling agents and fluorine leveling agents are preferable, and silicone leveling agents are particularly preferable.

Examples of the silicone leveling agent include polyether-modified silicone, polyester-modified silicone, perfluoro-modified silicone, reactive silicone, polydimethylsiloxane, and polymethylalkylsiloxane.
Such silicone leveling agents include “SILWET series”, “SUPERSILWET series”, “ABNSILWET series” manufactured by Nippon Unicar Co., Ltd., “KF series”, “X-22 series” manufactured by Shin-Etsu Chemical Co., Ltd., Big Chemie Japan “BYK-300 series” manufactured by Kyoeisha Chemical Co., Ltd. “Granol series” manufactured by Kyoeisha Chemical Co., Ltd. “SH series”, “ST series”, “FZ series” manufactured by Toray Dow Corning Co., Ltd. “FM Series” manufactured by GE Corporation, “TSF Series” manufactured by GE Toshiba Silicone Co., Ltd. (named above) are commercially available.

As the fluorine leveling agent, a compound having a fluoroalkyl group is preferred. Such a fluoroalkyl group may be a linear or branched structure having 1 to 20 carbon atoms, an alicyclic structure (preferably a 5-membered ring or 6-membered ring), and may have an ether bond. The fluorine-based leveling agent may be a polymer or an oligomer.
Moreover, as a fluorine-type leveling agent, the leveling agent in which a hydrophobic group has a perfluorocarbon chain is mentioned. Specifically, fluoroalkylcarboxylic acid, N-perfluorooctanesulfonyl glutamate disodium, sodium 3- (fluoroalkyloxy) -1-alkylsulfonate, 3- (ω-fluoroalkanoyl-N-ethylamino) -1 -Sodium propanesulfonate, N- (3-perfluorooctanesulfonamido) propyl-N, N-dimethyl-N-carboxymethyleneammonium betaine, perfluoroalkylcarboxylic acid, perfluorooctanesulfonic acid diethanolamide, perfluoroalkylsulfone Acid salt, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, perfluoroalkylsulfonamidopropyltrimethylammonium salt, perfluoroalkyl-N-ethyls Honirugurishin salts, phosphoric acid bis (N- perfluorooctylsulfonyl -N- ethylamino ethyl) and the like.
Examples of such fluorine leveling agents include “Polyflow 600” manufactured by Kyoeisha Chemical Co., Ltd., “R-2020, M-2020, R-3833, M-3833” manufactured by Daikin Chemical Industries, Ltd., Dainippon Examples thereof include “Megafac F-171, F-172D, F-179A, F-470, F-475, R-08, Defender MCF-300” (trade name) manufactured by Ink Corporation.
As the fluorine leveling agent, the materials shown in the above chemical formulas 1 to 5 can also be used.

Examples of acrylic leveling agents include “ARUFON-UP1000 series”, “UH2000 series”, “UC3000 series” manufactured by Toa Gosei Chemical Co., Ltd., “Polyflow 77” (trade name) manufactured by Kyoeisha Chemical Co., Ltd. It is commercially available.

  When there is too little content of the leveling agent in an optical function layer, it will become difficult to obtain the leveling effect of a coating film. When there is too much content of a leveling agent, it will become difficult to produce the aggregate of an inorganic component.

  From the above viewpoint, the content of the leveling agent in the optical functional layer is preferably in the range of 0.05 to 3% by mass with respect to 100% by mass of all components (excluding the organic solvent) of the optical functional layer. The range of ˜2 mass% is more preferable, and the range of 0.2 to 1 mass% is particularly preferable.

The compounding amount of the resin component such as ionizing radiation curable resin is 50% by mass or more, and preferably 60% by mass or more with respect to the total mass of the solid component in the resin composition constituting the optical functional layer. Although an upper limit is not specifically limited, For example, it is 99.8 mass%. If it is less than 50% by mass, there is a problem that sufficient hardness cannot be obtained.
The solid content of the resin component such as ionizing radiation curable resin includes all solid content other than the inorganic component and fine particles described later, and the solid content of the resin component such as ionizing radiation curable resin. As well as solid contents of other optional components.

(Inorganic component)
The inorganic component used in the present invention is not particularly limited as long as it is contained in the optical functional layer and aggregates during film formation to form the second phase and a random aggregated structure. As the inorganic component, inorganic nanoparticles can be used. Inorganic nanoparticles include metal oxides and metals such as silica, tin oxide, indium oxide, antimony oxide, alumina, titania and zirconia, metal oxide sols such as silica sol, zirconia sol, titania sol and alumina sol, aerosil, swelling Clay and layered organic clay. One kind of the inorganic nanoparticles may be used, or a plurality of kinds may be used.
The fine particles and the inorganic component (inorganic nano fine particles) are separate and can be distinguished by the particle size.

Among these inorganic nanoparticles, layered organoclay is preferable because it can stably form a random aggregated structure. The reason why the layered organic clay can stably form a random aggregated structure is that the layered organic clay has high compatibility with the resin component (organic component) and also has cohesiveness. It is easy to form a structure in which these phases are complicated, and it is easy to form a random aggregated structure during film formation. In the present invention, the layered organic clay refers to an organic onium ion introduced between the layers of the swellable clay. Layered organic clay has low dispersibility with respect to a specific solvent, and when a layered organic clay and a solvent having specific properties are used as a coating for forming an optical functional layer, a random aggregated structure is formed by selecting the solvent. An optical functional layer having surface irregularities is formed.

Swellable clay Swellable clay has only a cation exchange ability and can swell by taking water between the layers of the swellable clay. ). Moreover, the mixture of a natural product and a synthetic product may be sufficient.
Examples of the swellable clay include mica, synthetic mica, vermiculite, montmorillonite, iron montmorillonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, isallite, kanemite, layered titanic acid, smectite, and synthetic smectite. Etc. These swellable clays may be used alone or in combination.

Organic Onium Ion The organic onium ion is not limited as long as it can be organized using the cation exchange property of the swellable clay.
Examples of onium ions include quaternary ammonium salts such as dimethyl distearyl ammonium salt and trimethyl stearyl ammonium salt, ammonium salts having a benzyl group or a polyoxyethylene group, phosphonium salts, pyridinium salts, and imidazolium salts. Ions consisting of can be used. Examples of the salt include salts with anions such as Cl ⁻ , Br ⁻ , NO ₃ ⁻ , OH ⁻ , and CH ₃ COO ⁻ . As the salt, a quaternary ammonium salt is preferably used.
The functional group of the organic onium ion is not limited, but it is preferable to use a material containing any one of an alkyl group, a benzyl group, a polyoxypropylene group, and a phenyl group because antiglare properties are easily exhibited.

The preferred range of the alkyl group is 1 to 30 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, octadecyl, etc. Is mentioned.

The preferable range of n in the polyoxypropylene group [(CH ₂ CH (CH ₃ ) O) _n H or (CH ₂ CH ₂ CH ₂ O) _n H] is 1 to 50, more preferably 5 to 50. The more the number of moles added, the better the dispersibility in the organic solvent, but if it is too much, the product will become sticky, so if the emphasis is placed on the dispersibility in the solvent, the number of n is 20-50 are more preferable. Moreover, when the number of n is 5-20, a product is non-adhesive and the grindability is excellent. Further, from the viewpoint of dispersibility and handling, the total number of n in the quaternary ammonium is preferably 5-50.

Specific examples of the quaternary ammonium salt include tetraalkylammonium chloride, tetraalkylammonium bromide, polyoxypropylene / trialkylammonium chloride, polyoxypropylene / trialkylammonium bromide, di (polyoxypropylene) / dialkylammonium. Examples thereof include chloride, di (polyoxypropylene) · dialkylammonium bromide, tri (polyoxypropylene) · alkylammonium chloride, tri (polyoxypropylene) · alkylammonium bromide and the like.

In the quaternary ammonium ion of the general formula (I), R ¹ is preferably a methyl group or a benzyl group. R ² is preferably an alkyl group having 1 to 12 carbon atoms, and particularly preferably an alkyl group having 1 to 4 carbon atoms. R ³ is preferably an alkyl group having 1 to 25 carbon atoms. R ⁴ is preferably an alkyl group having 1 to 25 carbon atoms, a (CH ₂ CH (CH ₃ ) O) _n H group or a (CH ₂ CH ₂ CH ₂ O) _n H group. n is preferably 5 to 50.

In addition, it is preferable to use alumina sol as the inorganic nanoparticles because the surface hardness of the optical functional layer is improved and the scratch resistance is also improved.

The inorganic nanoparticles may be modified. A silane coupling agent can be used for the modification of the inorganic nanoparticles. Examples of the silane coupling agent include vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ -Acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, γ-acryloyloxypropyltriethoxysilane and the like are used. The silane coupling agent may have a functional group copolymerizable with the polymerizable double bond of the radiation curable resin constituting the resin component.

The average particle size of the inorganic nanoparticles is preferably 100 nm or less, more preferably 50 nm or less, and most preferably 20 nm or less. As long as the inorganic nanoparticle has cohesiveness, the lower limit of the average particle diameter is not limited, but is 1 nm, for example. When the average particle size of the inorganic nanoparticles exceeds 100 nm, the haze value of the optical laminate tends to increase, and a phenomenon such as whitening is easily observed and the contrast is lowered.

0.1-10 mass% contains the compounding quantity of an inorganic component with respect to the total mass of the solid component in a resin composition, and 0.2-5 mass% is especially suitable. When the blending amount of the inorganic component is 0.1% by mass, there is a problem that a sufficient number of surface irregularities are not formed and the antiglare property is insufficient. When the compounding amount of the inorganic component exceeds 10% by mass, the number of surface irregularities increases, and there is a problem that visibility is impaired.

(solvent)
As a solvent for forming surface irregularities for obtaining antiglare properties, it is preferable to contain a first solvent and a second solvent.
By adding the first solvent and the second solvent to the resin composition of the present invention, the coating composition for forming an optical functional layer of the present invention can be obtained. Since the coating material for forming an optical functional layer of the present invention contains the first solvent and the second solvent described above, fine particles that have been considered to be essential for creating the uneven surface shape of the optical functional layer are added. Even if it does not, the surface uneven | corrugated shape of an optical function layer can be created.

A 1st solvent means what can be disperse | distributed in the state with transparency, without producing turbidity substantially in an inorganic component. “Substantially no turbidity” includes not turbidity at all, but also includes those that can be regarded as not turbid. Specifically, the first solvent refers to a solvent having a haze value of 10% or less with respect to 100 parts by mass of the inorganic component by adding and mixing 1000 parts by mass of the first solvent. The haze value of the mixed solution obtained by adding and mixing the first solvent is preferably 8% or less, and more preferably 6% or less. In addition, the lower limit value of the haze value of the liquid mixture is not particularly limited, but is, for example, 0.1%. As the first solvent, for example, a so-called small-polar solvent (nonpolar solvent) can be used.

A 2nd solvent means what can be disperse | distributed in the state which produced the turbidity in the inorganic component. Specifically, the second solvent is one having a haze value of 30% or more of a mixed solution obtained by adding 1000 parts by mass of the second solvent to 100 parts by mass of the inorganic component. The haze value of the mixed solution obtained by adding the second solvent and mixing is preferably 40% or more, and more preferably 50% or more. In addition, although the upper limit of the haze value of a liquid mixture is not specifically limited, For example, it is 99%.
As the second solvent, for example, a so-called polar solvent can be used.
In addition, the haze value calculated | required when determining a 1st solvent and a 2nd solvent was measured according to JISK7105.

The first solvent and the second solvent that can be used vary depending on the type of the inorganic component. Solvents that can be used as the first solvent and the second solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, butanol, isopropyl alcohol (IPA), and isobutanol; acetone, methyl ethyl ketone (MEK), Ketones such as cyclohexanone and methyl isobutyl ketone (MIBK); ketone alcohols such as diacetone alcohol; aromatic hydrocarbons such as benzene, toluene and xylene; glycols such as ethylene glycol, propylene glycol and hexylene glycol; ethyl Glycol ethers such as cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, diethyl cellosolve, diethyl carbitol, propylene glycol monomethyl ether; N-methyl Pyrrolidone, dimethyl formamide, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, esters such as amyl acetate; dimethyl ether, and diethyl ether, it is possible to use water or the like. One of these solvents may be used as the first solvent or the second solvent, or a plurality of these solvents may be mixed to form the first solvent or the second solvent.

Here, it is preferable to use a mixture of the first solvent and the second solvent because surface irregularities for obtaining antiglare properties can be easily formed. The mixing ratio of the first solvent and the second solvent is preferably a mass ratio in the range of 10:90 to 90:10 because surface irregularities for obtaining antiglare properties can be easily formed. The mixing ratio of the first solvent and the second solvent is preferably in the range of 15:85 to 85:15, and more preferably in the range of 20:80 to 80:20, by mass ratio. If the first solvent is less than 10 parts by mass, there is a problem that appearance defects due to undispersed matter occur. If the first solvent exceeds 90 parts by mass, there is a problem that surface irregularities for obtaining sufficient antiglare property cannot be obtained.

Moreover, the compounding quantity of a resin composition and a solvent (what combined the 1st solvent and the 2nd solvent) should just be the range of 70: 30-30: 70 by mass ratio.
When the resin composition is less than 30 parts by mass, there are problems that drying unevenness occurs and the appearance is deteriorated, the number of surface irregularities is increased, and visibility is impaired.
If the resin composition exceeds 70 parts by mass, the solubility (dispersibility) of the solid content tends to be impaired, and there is a problem that the film cannot be formed.

(Fine particles)
The resin composition contains translucent fine particles. The optical functional layer-forming coating material obtained by adding a solvent to the resin composition can be applied on a light-transmitting substrate, and then the optical functional layer-forming coating material can be cured to form an optical functional layer. By adding translucent fine particles to the resin composition, it becomes easy to adjust the shape and number of surface irregularities of the optical functional layer.

As the translucent fine particles, an organic translucent resin made of acrylic resin, polystyrene resin, styrene-acrylic copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, polyfluoroethylene resin, etc. Fine inorganic particles such as fine particles, silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, and antimony oxide can be used. The refractive index of the light-transmitting fine particles is preferably 1.40 to 1.75. When the refractive index is less than 1.40 or greater than 1.75, the difference in refractive index from the light-transmitting substrate or the resin matrix is large. As a result, the total light transmittance decreases. Further, the difference in refractive index between the translucent fine particles and the resin is preferably 0.2 or less. The average particle diameter of the translucent fine particles is preferably in the range of 0.3 to 7.0 μm, more preferably 1.0 to 7.0 μm, and further preferably 2.0 to 6.0 μm.
When the particle size is smaller than 0.3 μm, the antiglare property is lowered, and when it is larger than 7.0 μm, glare is generated and the surface unevenness becomes too large and the surface becomes whitish. Absent. In addition, the ratio of the light-transmitting fine particles contained in the resin is not particularly limited, but it is 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin composition. It is preferable for satisfaction, and it is easy to control the fine uneven shape and haze value on the surface of the optical functional layer. Here, “refractive index” refers to a measured value according to JIS K-7142. Further, “average particle diameter” refers to an average value of the diameters of 100 particles actually measured with an electron microscope.

The blending amount of the fine particles is 0.1% by mass or more, and preferably 1.0% by mass or more with respect to the total mass of the solid components in the resin composition constituting the optical functional layer. Although an upper limit is not specifically limited, For example, it is 5.0 mass%. If it is less than 0.1% by mass, there is a problem that sufficient antiglare property cannot be obtained.

Antistatic agent (conductive agent)
The optical functional layer of the present invention may contain an antistatic agent (conductive agent). Addition of the conductive agent can effectively prevent dust adhesion on the surface of the optical laminate. Specific examples of the antistatic agent (conductive agent) include quaternary ammonium salts, pyridinium salts, various cationic compounds having a cationic group such as first to third amino groups, sulfonate groups, sulfate ester bases, Anionic compounds having an anionic group such as phosphate ester base and phosphonate base, amphoteric compounds such as amino acid series and amino sulfate ester series, nonionic compounds such as amino alcohol series, glycerin series and polyethylene glycol series, tin and titanium And metal chelate compounds such as acetylacetonate salts thereof, and compounds obtained by increasing the molecular weight of the compounds listed above. In addition, a monomer or oligomer having a tertiary amino group, a quaternary ammonium group, or a metal chelate portion and polymerizable by ionizing radiation, or an organometallic compound such as a coupling agent having a functional group, etc. Polymerizable compounds can also be used as antistatic agents.

Examples of the antistatic agent include conductive fine particles. Specific examples of the conductive fine particles include those made of a metal oxide. Examples of such metal oxides include ZnO, CeO ₂ , Sb ₂ O ₂ , SnO ₂ , indium tin oxide often abbreviated as ITO, In ₂ O ₃ , Al ₂ O ₃ , antimony-doped tin oxide (abbreviation) ATO), aluminum-doped zinc oxide (abbreviation: AZO), and the like. The conductive fine particles are those having a so-called submicron size of 1 micron or less, and preferably have an average particle size of 0.1 nm to 0.1 μm.

Another specific example of the antistatic agent (conductive agent) is a conductive polymer. The material is not particularly limited. For example, aliphatic conjugated polyacetylene, polyacene, polyazulene, aromatic conjugated polyphenylene, heterocyclic conjugated polypyrrole, polythiophene, polyisothianaphthene, heteroatom-containing conjugated system. Polyaniline, polythienylene vinylene, mixed conjugated poly (phenylene vinylene), double-chain conjugated system having a plurality of conjugated chains in the molecule, derivatives of these conductive polymers, and conjugates thereof Examples thereof include at least one selected from the group consisting of conductive composites that are polymers obtained by grafting or block-copolymerizing polymer chains to saturated polymers. Among these, it is more preferable to use an organic antistatic agent such as polythiophene, polyaniline, polypyrrole. By using the above-mentioned organic antistatic agent, it is possible to exhibit excellent antistatic performance and at the same time increase the total light transmittance of the optical laminate and reduce the haze value. An anion such as an organic sulfonic acid or iron chloride can be added as a dopant (electron donor) for the purpose of improving conductivity and improving antistatic performance. In view of the effect of dopant addition, polythiophene is particularly preferable because of its high transparency and antistatic properties. As the polythiophene, oligothiophene can also be preferably used. The derivative is not particularly limited, and examples thereof include polyphenylacetylene, polydiacetylene alkyl group-substituted products, and the like.

<Optical laminate>
After coating the optical functional layer forming paint containing the above components on the light-transmitting substrate, heat or ionizing radiation (for example, electron beam or ultraviolet irradiation) is applied to cure the optical functional layer forming paint. By doing so, an optical functional layer can be formed, and the optical layered body of the present invention can be obtained.
The optical functional layer may be formed on one side or both sides of the translucent substrate.

Moreover, you may have another layer on the opposite surface of an optical function layer between an optical function layer and a translucent base | substrate, and you may have another layer on an optical function layer. Examples of the other layers include a polarizing layer, a light diffusion layer, a low reflection layer, an antifouling layer, an antistatic layer, an ultraviolet / near infrared (NIR) absorption layer, a neon cut layer, and an electromagnetic wave shielding layer. Can do.

The thickness of the optical functional layer is preferably in the range of 1.0 to 12.0 μm, more preferably in the range of 2.0 to 11.0 μm, and still more preferably in the range of 3.0 to 10.0 μm. is there. When the optical functional layer is thinner than 1.0 μm, curing failure due to oxygen inhibition occurs at the time of ultraviolet curing, and the wear resistance of the optical functional layer tends to deteriorate. When the optical functional layer is thicker than 12.0 μm, curling due to curing shrinkage of the optical functional layer, generation of microcracks, decrease in adhesion to the translucent substrate, and further decrease in light transmission may occur. End up. And it becomes a cause of the cost increase by the increase in the amount of required coating materials accompanying the increase in film thickness.

In the optical laminate of the present invention, the image clarity is preferably in the range of 5.0 to 85.0 (value measured using a 0.5 mm optical comb in accordance with JIS K7105), and more preferably 20.0 to 75.0. . If the image clarity is less than 5.0, the contrast deteriorates, and if it exceeds 85.0, the antiglare property deteriorates, so that it is not suitable for the optical laminate used for the display surface.

Next, the uneven | corrugated shape of the optical function layer which comprises the optical laminated body of this invention is explained in full detail.
The uneven shape of the optical functional layer is determined according to ASME / 1995 (ASME: American Society of Mechanical Engineers). On the surface of the optical functional layer having a concavo-convex shape, the proportion of the inclination angle distribution of 0.2 degrees or less in the inclination angle distribution of the measured total length of the concavo-convex shape is within the range of 30% or more and 95% or less. It is possible to obtain an optical laminated body having a balanced balance of glare, darkness in a bright room, dark room contrast, and glare prevention.
The ratio of the tilt angle distribution of 0.2 degrees or less to the tilt angle distribution of the measured total length in which the concavo-convex shape is measured is preferably 35% or more and 75% or less, and more preferably 38% or more and 58% or less. .

In the distribution of the inclination angle of the concavo-convex shape defined in the present invention, first, the concavo-convex shape of the optical functional layer is measured according to ASME / 1995. Next, the height (Y) of the unevenness for each measurement length (X) of 0.5 μm is calculated in the total measurement length in which the uneven shape was measured, and the local inclination (ΔZ _i ) is calculated from the following equation.

Here, ΔZ _i refers to a local inclination at an arbitrary measurement position dX _i . Subsequently, the inclination angle (θ) is calculated from the following equation.

  After obtaining the inclination angle (θ) over the entire measurement length by the above formula, a frequency distribution with the inclination angle (θ) in increments of 0.1 ° is created, and the ratio (%) having the predetermined inclination angle defined in the present invention )

In the optical layered body of the present invention, the arithmetic average height Ra is preferably 0.040 or more and less than 0.200 μm, preferably 0.040 to less than 0.150 μm, as a fine uneven shape of the optical functional layer. More preferably, it is particularly preferably 0.040 to less than 0.100 μm. When the arithmetic average height Ra is less than 0.040 μm, the antiglare property of the optical laminate is insufficient. When the arithmetic average height Ra is 0.200 μm or more, the blackness of the optical laminate is deteriorated.

Average length (RSm) exists in the range of 30-300 micrometers, More preferably, it is 50-250 micrometers, More preferably, it is 100-250 micrometers. If it is less than 30 μm, there is a demerit that the blackness of the optical laminate deteriorates due to the increased surface scattering. If it exceeds 300 μm, there is a disadvantage that the antiglare property deteriorates.

The maximum height (Rz) is in the range of 0.300 to 1.200 μm, more preferably 0.400 to 1.000 μm, and still more preferably 0.500 to 0.900 μm. If it is less than 0.300 μm, there is a disadvantage that the antiglare property deteriorates. 1. If it exceeds 200 μm, there is a demerit that the blackness of the optical laminate deteriorates.

<Polarizing substrate>
In the present invention, a polarizing substrate may be laminated on a light transmitting substrate opposite to the optical functional layer. Here, as the polarizing substrate, a light absorbing polarizing substrate that transmits only specific polarized light and absorbs other light, or a light reflecting polarizing substrate that transmits only specific polarized light and reflects other light is used. I can do it. As the light-absorbing polarizing substrate, a film obtained by stretching polyvinyl alcohol, polyvinylene or the like can be used. For example, it can be obtained by uniaxially stretching polyvinyl alcohol adsorbed with iodine or a dye as a dichroic element. Polyvinyl alcohol (PVA) film. As a light-reflective polarizing substrate, for example, two kinds of polyester resins (PEN and PEN copolymer) having different refractive indexes in the stretching direction when stretched are alternately laminated and stretched by several hundreds of extrusion techniques. "DBEF" manufactured by 3M, or a cholesteric liquid crystal polymer layer and a quarter-wave plate are laminated, and light incident from the cholesteric liquid crystal polymer layer side is separated into two circularly polarized light beams that are opposite to each other. Nitto Denko's “Nipox” and Merck's “Transmax”, which are configured to convert circularly polarized light that is transmitted through the cholesteric liquid crystal polymer layer and converted into linearly polarized light by a quarter-wave plate, and the like. .
By laminating the polarizing substrate and the optical laminate directly or via an adhesive layer, it can be used as a polarizing plate.

<Display device>
The optical laminate of the present invention is applied to display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), electroluminescence displays (ELD), cathode ray tube display devices (CRT), and surface electric field displays (SED). can do. It is particularly preferably used for a liquid crystal display (LCD). Since the optical layered body of the present invention has a translucent substrate, the translucent substrate side is used by adhering to the image display surface of the image display device.

When the optical layered body of the present invention is used as one side of the surface protective film of the polarizing plate, twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically It can be preferably used for a transmissive, reflective, or transflective liquid crystal display device in a mode such as a compensated bend cell (OCB).

<Method for producing optical laminate>
As a method for applying the coating material for forming an optical functional layer on the translucent substrate, a normal coating method or printing method is applied. Specifically, air doctor coating, bar coating, blade coating, knife coating, reverse coating, transfer roll coating, gravure roll coating, kiss coating, cast coating, spray coating, slot orifice coating, calendar coating, dam coating, dip coating Coating such as die coating, intaglio printing such as gravure printing, printing such as stencil printing such as screen printing, and the like can be used.

EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not restrict | limited to these.

[Example 1]
A coating for forming an optical functional layer obtained by stirring the predetermined mixture shown in Table 1 for 30 minutes with a disper was used as a transparent substrate TAC (made by Fuji Film Co., Ltd.) having a film thickness of 60 μm and a total light transmittance of 92%. Applied to one side of TD60UL by roll coating method (line speed: 20 m / min), pre-dried at 30-50 ° C. for 20 seconds, dried at 100 ° C. for 1 minute, and nitrogen atmosphere (replaced with nitrogen gas) ) Was irradiated with ultraviolet rays (lamp; condensing high-pressure mercury lamp, lamp output: 120 W / cm, number of lamps: 4 lamps, irradiation distance: 20 cm) to cure the coating film. Thus, the optical laminated body of Example 1 which has a 4.1 micrometer-thick optical function layer was obtained.

[Example 2]
An optical laminated body of Example 2 having an optical functional layer with a thickness of 5.5 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . From the SEM and EDS results, it was confirmed that the optical functional layer constituting the obtained laminate had at least a first phase and a second phase and formed a random aggregated structure.

[Example 3]
An optical laminated body of Example 3 having an optical functional layer with a thickness of 5.5 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . From the SEM and EDS results, it was confirmed that the optical functional layer constituting the obtained laminate had at least a first phase and a second phase and formed a random aggregated structure.

[Example 4]
An optical laminated body of Example 4 having an optical functional layer having a thickness of 5.0 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . From the SEM and EDS results, it was confirmed that the optical functional layer constituting the obtained laminate had at least a first phase and a second phase and formed a random aggregated structure.

[Example 5]
An optical layered body of Example 5 having an optical functional layer with a thickness of 5.9 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . From the SEM and EDS results, it was confirmed that the optical functional layer constituting the obtained laminate had at least a first phase and a second phase and formed a random aggregated structure. Here, the SEM result seen from the optical functional layer surface of the obtained optical laminate is shown in FIG. 2, the SEM result of the sectional view of the optical laminate is shown in FIG. 3, and the EDS result seen from the optical functional layer surface of the optical laminate is shown. This is shown in FIG. From these results, it was confirmed that the optical functional layer constituting the obtained optical laminate had at least a first phase and a second phase and formed a random aggregated structure.

[Example 6]
An optical laminated body of Example 5 having an optical functional layer with a thickness of 5.4 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . From the SEM and EDS results, it was confirmed that the optical functional layer constituting the obtained laminate had at least a first phase and a second phase and formed a random aggregated structure.

[Comparative Example 1]
An optical layered body of Comparative Example 1 having an optical functional layer having a thickness of 4.3 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . Here, from the SEM and EDS results of the obtained laminate, the optical functional layer constituting the obtained optical laminate does not form a random aggregate structure but forms a sea-island structure composed of aggregates of translucent organic fine particles. It was confirmed that

[Comparative Example 2]
An optical layered body of Comparative Example 2 having an optical functional layer having a thickness of 5.8 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . Here, from the SEM and EDS results of the obtained laminate, the optical functional layer constituting the obtained optical laminate does not form a random aggregate structure, and the first phase and the second phase are the entire film surface. It was confirmed that a sea-island structure was formed.

[Comparative Example 3]
An optical layered body of Comparative Example 3 having an optical functional layer with a thickness of 6.6 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . Here, the SEM result seen from the optical functional layer surface of the obtained optical laminate is shown in FIG. 5, and the EDS result seen from the optical functional layer surface of the optical laminate is shown in FIG. The optical functional layer constituting the obtained optical laminate is phase-separated into a first phase and a second phase, but no random aggregate structure is formed because the optical functional layer does not contain fine particles. It was confirmed.

[Comparative Example 4]
An optical laminate of Comparative Example 4 having an optical functional layer having a thickness of 5.5 μm was obtained in the same manner as in Example 1 except that the optical functional layer-forming coating material was changed to the predetermined mixed solution shown in Table 1. . Here, from the SEM and EDS results of the obtained optical laminate, the optical functional layer constituting the obtained optical laminate does not form a random aggregate structure, but has a sea-island structure composed of aggregates of translucent organic fine particles. The formation was confirmed.

[Comparative Example 5]
An optical layered body of Comparative Example 4 having an optical functional layer having a thickness of 4.8 μm was obtained in the same manner as in Example 1 except that the coating material for forming the optical functional layer was changed to the predetermined mixed liquid shown in Table 1. . Here, FIG. 7 shows the SEM results from the optical functional layer surface of the optical laminate of the obtained optical laminate. It was confirmed that the optical functional layer constituting the obtained optical layered product did not form a random aggregated structure but formed a sea-island structure composed of aggregated translucent organic fine particles.

[Comparative Example 6]
An optical laminated body of Comparative Example 4 having an optical functional layer having a thickness of 4.0 μm was obtained in the same manner as in Example 1 except that the optical functional layer-forming coating material was changed to the predetermined mixed liquid described in Table 1. . Here, from the SEM and EDS results of the obtained optical laminate, the optical functional layer constituting the obtained optical laminate does not form a random aggregated structure, but forms a sea-island structure composed of amorphous silica aggregates. It was confirmed that

The materials used in the above examples are summarized in Table 1, and the materials used in the comparative examples are summarized in Table 2.

SEM and EDS were photographed under the following conditions.
SEM
The state of the coating layer surface of the laminates obtained in Examples and Comparative Examples, and information on contained elements were observed by SEM. Observation was performed after depositing gold or carbon on the surface of the coating layer. The conditions for SEM observation are shown below.
Analytical instrument: JSM-6460LV (manufactured by JEOL Ltd.)
Pretreatment device: C (carbon) coating: 45 nm SC-701C (manufactured by Sanyu Electronics Co., Ltd.)
・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Au (gold) coating: 10nm SC-701AT modified (manufactured by Sanyu Electronics Co., Ltd.)
SEM condition: Acceleration voltage: 20KV or 15KV
Irradiation current: 0.15 nA
Degree of vacuum: High vacuum
Image detector: backscattered electron detector
Sample tilt: 0 degree

EDS
Information on the elements contained in the laminates obtained in Examples and Comparative Examples was observed by EDS. Observation was performed after carbon deposition on the coating layer surface. The conditions for EDS observation are shown below.
Analytical instrument: JSM-6460LV (manufactured by JEOL Ltd.)
Pretreatment device: C (carbon) coating: 45 nm SC-701C (manufactured by Sanyu Electronics Co., Ltd.)
EDS condition: Acceleration voltage: 20KV
Irradiation current: 0.15 nA
Degree of vacuum: High vacuum
Image detector: backscattered electron detector
MAP resolution: 128 x 96 pixels
Image resolution: 1024 x 768 pixels

(Evaluation methods)
Next, the following items were evaluated for the optical laminates of Examples and Comparative Examples.

(Film thickness)
The film thickness was determined by observing the cross section of the optical laminate that had been frozen and broken in liquid nitrogen using the SEM.

(Haze value)
The haze value (all Hz) was measured using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku Co., Ltd.) according to JIS K7105.

(Surface roughness)
The arithmetic average height Ra, the maximum height Rz, and the average length RSm were measured using a surface roughness measuring instrument (trade name: Surfcorder SE1700α, manufactured by Kosaka Laboratory Co., Ltd.) in accordance with JIS B0601-2001.

The distribution of inclination angles was calculated according to the following procedure.
First, in accordance with ASME / 1995, a surface roughness measuring device (trade name: Surfcorder SE1700α, manufactured by Kosaka Laboratory Co., Ltd.) was used to form an optical functional layer (a surface not equipped with a translucent substrate). The uneven shape was measured. The measurement is performed by setting each optical laminate in the example and the comparative example at a predetermined position of the surfcoder SE1700α, selecting “ASME95”, and further selecting “Δa” as a parameter. be able to.
The measurement conditions are as follows.
・ Measurement length: 4.0 mm
・ Filter: GAUSS
.Lambda.c (roughness cutoff value): 0.8
・ Λf (swell cutoff value): 10λc
・ Vertical magnification: 20,000 times ・ Horizontal magnification: 500 times

  Next, the height (Y) of the unevenness for each measurement length (X) of 0.5 μm was calculated in the total measurement length in which the uneven shape was measured, and the local inclination (ΔZi) was calculated from the following equation.

Here, ΔZi refers to a local inclination at an arbitrary measurement position dXi.

  Subsequently, the inclination angle (θ) was calculated from the following equation.

After calculating the inclination angle (θ) over the entire measurement length by the above equation, a frequency distribution with the inclination angle (θ) in increments of 0.1 ° is created, and the ratio of those having the predetermined inclination angle defined in the present invention is obtained. It was.

(Image clarity)
According to JIS K7105, a measuring device (trade name: ICM-1DP, manufactured by Suga Test Instruments Co., Ltd.) was used, and the measuring device was set to a transmission mode, and measurement was performed at an optical comb width of 0.5 mm.

(Anti-glare)
The antiglare property was numerically determined by two methods, quantitative evaluation and qualitative evaluation. When the sum of the judgment values of both evaluations was 5 points or more, ◎ when 4 points, ◯ when 3 points or less.

(Quantitative evaluation of anti-glare properties)
When the image sharpness value was 5 or more and less than 40, 3 points were given, when 40 or more and less than 80, 2 points, and when 80 or more, 1 point was given.

(Qualitative evaluation of anti-glare property)
Attached to the black acrylic board (Mitsubishi Rayon Acrylite L502) through a colorless and transparent adhesive on the opposite side of the optical laminate formation surface, and two fluorescent lamps are exposed in 400 lux environmental illumination Using a fluorescent lamp arranged in parallel as a light source, light was reflected at an angle of 45 to 60 degrees, and the reflected image was visually observed from the regular reflection direction to determine the degree of reflection of the fluorescent lamp. Three points when the reflected image of two fluorescent lamps is blurred so that one image is blurred, two points can be recognized, but when the outline of the fluorescent lamp is blurred, two points, the outline of the two fluorescent lamps is not blurred 1 point when clearly visible.

(Black)
The darkness in the dark room was numerically determined by two methods, quantitative evaluation and qualitative evaluation. When the sum of the judgment values of both evaluations is 6 points, ◎ when 5 points, ◯ when 4 points or less.

(Quantitative evaluation of black taste)
The front surface of the liquid crystal display screen is bonded to the surface of the liquid crystal display (trade name: LC-37GX1W, manufactured by Sharp Corporation) via a colorless and transparent adhesive layer on the surface opposite to the optical laminate forming surface of the examples and comparative examples. The brightness of the liquid crystal display surface is set to 200 lux with a fluorescent lamp (trade name: HH4125GL, manufactured by National Corporation) from a direction of 60 ° above, and the brightness when the liquid crystal display is displayed in white and black is colored. luminance meter (trade name: BM-5A, manufactured by Topcon Corporation) was measured by the resulting black state of luminance (cd / ^{m 2)} and the white display of the luminance (cd / ^{m 2)} in the following equation The reduction rate was calculated by the following formula, assuming that the contrast of the plain polarizing plate was 100%. When the rate of decrease was less than 5%, 3 points, 5% or more and less than 10%, 2 points, and 10% or more, 1 point.
Contrast = Brightness of white display / Brightness of black display Decrease rate = Contrast (optical laminate) / Contrast (plain polarizing plate)
In the present invention, the plain polarizing plate is a laminate in which a TAC film is bonded to both sides of a polyvinyl alcohol (PVA) film obtained by uniaxially stretching polyvinyl alcohol adsorbed with iodine or a dye as a dichroic element. Say.

(Qualitative evaluation of blackness)
Attached to the black acrylic board (Mitsubishi Rayon Acrylite L502) through a colorless and transparent adhesive on the opposite side of the optical laminate formation surface, and two fluorescent lamps are exposed in 400 lux environmental illumination In Example 1, a fluorescent lamp arranged in parallel with the light source is used to reflect light at an angle of 45 to 60 degrees, and the blackness of the portion other than the reflected image of the light source is visually observed from the regular reflection direction. Compared to the film shown, 3 points were given when the blackness was excellent, 2 points when the blackness was comparable, and 1 point when the blackness was inferior.

(Dark room contrast)
The dark room contrast was bonded to the surface of the liquid crystal display (trade name: LC-37GX1W, manufactured by Sharp Corporation) on the surface opposite to the optical laminate formation surface of Examples and Comparative Examples via a colorless and transparent adhesive layer. The luminance when the liquid crystal display was set to white display and black display under the conditions was measured with a color luminance meter (trade name: BM-5A, manufactured by Topcon Corporation), and the resulting luminance during black display (cd / m ^2). ) And brightness at the time of white display (cd / m ² ) were calculated by the following formula, and the reduction rate was calculated by the following formula with the contrast of the plain polarizing plate as 100%. When the reduction rate was less than 3%, ◎ when it was 3% or more and less than 7%, and x when it was 7% or more.
Contrast = Brightness of white display / Brightness of black display Decrease rate = Contrast (optical laminate) / Contrast (plain polarizing plate)

(Glitter)
Glitter is a liquid crystal display (trade name: LL-T1620-B, manufactured by Sharp Corporation) with a resolution of 100 ppi through a colorless and transparent adhesive layer on the surface opposite to the optical laminate forming surface of each example and each comparative example. Bonded to the screen of a liquid crystal display (product name: nw8240-PM780, manufactured by Hewlett-Packard Japan) with a resolution of 150 ppi and a liquid crystal display (product name: PC-CV50FW, manufactured by Sharp) with a resolution of 200 ppi, respectively, in a dark room After the liquid crystal display is displayed in green, the resolution value when no luminance variation is confirmed in an image taken with a CCD camera (CV-200C, manufactured by Keyence Corporation) with a resolution of 200 ppi from the normal direction of each liquid crystal TV is , X for 100 ppi, ◯ for 150 ppi, ◎ for 200 ppi .

The obtained results are shown in Table 3.

As described above, according to the present invention, the optical system has excellent anti-glare properties, excellent darkness and glare prevention performance in a bright room, high dark room contrast, and excellent manufacturing stability. A laminate and a method for producing the optical laminate can be provided. In addition, a polarizing plate and a display device each including the optical layered body can be provided.

DESCRIPTION OF SYMBOLS 1 1st phase 2 2nd phase 3 Fine particle 15, 16 Optical function layer 20 Translucent base | substrate 30, 31 Fine particle 40 Resin

Claims (7)

An optical laminate in which an optical functional layer is laminated on a translucent substrate, wherein an uneven shape is formed on at least one surface of the optical functional layer, and an arithmetic average of the optical functional layer surface having the uneven shape The height (Ra) is 0.040 or more and less than 0.200, and the ratio of the inclination angle distribution of 0.2 degrees or less to the inclination angle distribution of the optical functional layer surface having the uneven shape is 30% or more and 95% or less. An optical laminated body characterized by being. The optical laminated body according to claim 1, wherein the optical functional layer is composed of one or more optical functional layers mainly composed of a radiation curable resin composition. The optical layered body according to claim 1, wherein the optical functional layer contains at least a radiation curable resin composition and translucent fine particles. The optical laminate according to claim 3, wherein the translucent fine particles have an average particle size of 0.3 to 7.0 µm. The optical layered body according to claim 1, wherein the optical functional layer has a film thickness larger than an average particle diameter of the translucent fine particles. A polarizing plate comprising a polarizing substrate laminated on a translucent substrate constituting the optical laminate according to claim 1. A display device comprising the optical layered body according to claim 1.