JP2011098445A - Optical laminate and method for manufacturing the same, and polarizing plate and display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical laminate capable of achieving both of antiglare and high contrast, a method for manufacturing the same, a polarizing plate with the optical laminate, and a display device with the optical laminate or the polarizing plate. <P>SOLUTION: The optical laminate includes a translucent base body, and at least one optically functional layer disposed on the translucent base body. The optically functional layer has a domain structure, and the relationship between a film thickness D of the optically functional layer and an average particle diameter r of a translucent fine particle included in the optically functional layer is within a range expressed by the following relational expression; 3×r<D≤10×r. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an optical laminate provided on the surface of a display such as a liquid crystal display (LCD) or a plasma display (PDP) and a method for producing the same, and a polarizing plate comprising the optical laminate, and the optical laminate or the polarized light. The present invention relates to a display device including a plate.

An image display surface in an image display device such as a liquid crystal display, a CRT (CRT) display, a projection display, a plasma display, or an electroluminescence display is required to be provided with scratch resistance so as not to be damaged when handled. Therefore, an optical laminate is disposed on the display surface. This optical laminate has a structure in which an optical functional layer is laminated on a translucent substrate such as polyethylene terephthalate (hereinafter referred to as “PET”) or triacetylcellulose (hereinafter referred to as “TAC”). It is.

The optical functional layer has desired properties. For example, an optical laminate in which the optical functional layer has a hard coat property can be used as a hard coat film provided with a hard coat layer. Moreover, the optical laminated body in which the fine concavo-convex structure is formed on the surface of the optical functional layer can be used as a hard coat film and also as an antiglare film having an antiglare layer. Furthermore, a light diffusion layer or a low refractive index layer can be used as the optical functional layer. Development of an optical laminate having a desired function has been promoted by using these optical functional layers such as a hard coat layer and an antiglare layer as a single layer or by combining a plurality of layers.

When an anti-glare film 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, an anti-glare film that can achieve high contrast even when anti-glare properties are reduced is demanded (high contrast AG). That is, since the antiglare property and the contrast are contradictory properties, it is difficult to satisfy both.

Then, development of the anti-glare film which can make anti-glare property and contrast compatible is advanced (for example, refer patent document 1). The antiglare film described in Patent Document 1 is a film in which a Benard cell structure is formed on the surface of the coating layer by convection generated when the solvent is volatilized, and then the resin contained in the coating layer is cured. The film thickness of the antiglare layer constituting the antiglare film formed by the method is set in the range of not less than the average particle diameter of the fine particles included in the antiglare layer and not more than 3 times the average particle diameter of the fine particles. .

Japanese Patent No. 4238936

However, although the antiglare film described in Patent Document 1 can achieve both the antiglare property and the contrast to some extent, the antiglare property and the contrast are insufficient. As one reason for this, in the antiglare film described in Patent Document 1, although the fine particles aggregate in the in-plane direction of the antiglare layer, the film thickness of the antiglare layer is not less than the average particle diameter of the fine particles included in the antiglare layer, Since the average particle diameter of the fine particles is in the range of 3 times or less, the aggregation of the fine particles is difficult to proceed. If the aggregation of the fine particles is difficult to proceed, the uneven structure on the surface of the antiglare layer becomes small and the antiglare property is insufficient. In addition, since the average particle diameter of the fine particles is larger than the film thickness of the antiglare layer, the average inclination angle of the unevenness formed on the surface becomes large and the bright room contrast becomes insufficient.

Therefore, the present invention includes an optical laminate capable of achieving both antiglare properties and high contrast, a method for producing the same, a polarizing plate comprising the optical laminate, and the optical laminate or the polarizing plate. An object of the present invention is to provide a display device.

The present invention achieves the above-mentioned object by the following technical configuration.

(1) A translucent substrate and at least one optical functional layer provided on the translucent substrate, the optical functional layer having a domain structure, and a film thickness D of the optical functional layer The optical layered body, wherein the average particle diameter r of the translucent fine particles contained in the optical functional layer is in a range represented by a relational expression of 3 × r <D ≦ 10 × r.
(2) The optical layered body according to (1), wherein the optical function layer has a thickness D in the range of 2 μm to 15 μm.
(3) The optical layered body according to (1) or (2), wherein the translucent fine particles contained in the optical functional layer have an average particle diameter r in the range of 0.5 μm to 5.0 μm. .
(4) The optical layered body according to any one of (1) to (3), wherein a domain structure formed in the optical functional layer is in a range of 20 to 1000 per 1 mm ² .
(5) The optical layered body according to any one of (1) to (4), wherein an arithmetic average roughness Ra on the surface of the optical functional layer is in a range of 0.05 μm to 0.20 μm.
(6) The optical laminated body according to any one of (1) to (5), wherein the unevenness average interval Sm on the surface of the optical functional layer is in the range of 50 μm to 200 μm.
(7) The optical layered body according to any one of (1) to (6), wherein an average inclination angle on the surface of the optical functional layer is in a range of 0.2 ° to 1.4 °.
(8) A polarizing plate comprising the optical laminate according to any one of (1) to (7).
(9) A display device comprising the optical laminate according to any one of (1) to (7).
(10) A coating material in which a resin component, a light-transmitting fine particle, a first solvent, and a second solvent are mixed is applied onto a light-transmitting substrate to form a coating layer, and the first layer included in the coating layer When the second solvent is volatilized, a convection is generated in the coating layer to form a domain structure, and then the resin component contained in the paint is cured to form an optical functional layer, and the optical functional layer film A method for producing an optical laminate, wherein the thickness D and the average particle diameter r of the light-transmitting fine particles contained in the optical functional layer satisfy a relational expression of 3 × r <D ≦ 10 × r.

ADVANTAGE OF THE INVENTION According to this invention, it comprises the optical laminated body which can make anti-glare property and high contrast compatible, its manufacturing method, the polarizing plate which comprises the said optical laminated body, and the said optical laminated body or the said polarizing plate. Thus, a display device can be provided.

It is a figure for demonstrating the domain structure in the optical function layer which comprises this invention, Comprising: (a) An enlarged plan view, (b) It is an expanded sectional side view. 2 is an optical micrograph of the optical layered body of Example 1. 2 is an optical micrograph of the optical layered body of Example 2. 4 is an optical micrograph of the optical layered body of Example 3. 4 is an optical micrograph of the optical layered body of Example 4. 2 is an optical micrograph of an optical laminate of Comparative Example 1. 6 is an optical micrograph of an optical laminate of Comparative Example 3. 6 is an optical micrograph of an optical laminate of Comparative Example 4.

The optical layered body according to the present embodiment has a configuration in which an optical functional layer is provided on a translucent substrate, and the optical functional layer has a domain structure. FIG. 1 is a diagram schematically showing the domain structure in the optical functional layer. (A) is the top view which showed the surface structure of the optical laminated body (optical function layer), (b) is the sectional side view which showed the side sectional structure of the optical laminated body.
Note that FIG. 1 is a conceptual diagram and may differ from the actual scale.

FIG. 1A is an enlarged plan view of an optical functional layer constituting the present invention. A plurality of domain structures 21 exist in the optical functional layer constituting the present invention, and a plurality of domain structures exist adjacent to each other. Further, a non-domain structure 22 exists in the gap between adjacent domain structures. The domain structure 21 is an aggregate of translucent fine particles, and the non-domain structure 22 is a translucent microparticle that exists individually without being a resin component or aggregate.

FIG.1 (b) is sectional drawing in the AA shown in Fig.1 (a). The optical functional layer 20 is formed on the translucent substrate 10. A convex structure is mainly formed in the upper part where the domain structure 21 exists (on the surface side of the optical functional layer 20), and a concave structure is formed in the upper part where the non-domain structure 22 exists. That is, surface irregularities of the optical functional layer are formed by the domain structure and the non-domain structure. Since the domain structure 21 is an aggregate of translucent fine particles, an uneven structure as well as a convex structure is formed on the upper portion of the domain structure 21 in accordance with the aggregated state of the translucent fine particles.
The surface unevenness of the optical functional layer formed by the domain structure has a smaller average inclination angle compared to the surface unevenness created using conventional fine particles, so that light diffusion on the surface is reduced and high contrast performance is exhibited. It will be advantageous.

The domain structure is an aggregate of translucent fine particles, but the number of aggregated translucent fine particles is preferably 100 or more, more preferably 300 or more, and particularly preferably 500 or more. preferable. The larger the number of aggregated translucent fine particles, the better. By gathering many translucent fine particles, a smooth surface uneven structure can be formed in the optical functional layer, which contributes to high contrast.

The number of domain structures per unit area is preferably 20 to 1000, more preferably 30 to 500, and particularly preferably 50 to 300 within a range of 1 mm ² . An optical laminate having an optical functional layer with the number of domain structures within the above range can be preferably used as an optical laminate capable of achieving antiglare properties and high contrast. If the number is less than 20, there is a problem that the gap between the surface irregularities becomes large and glare occurs. If it exceeds 1000, the number of surface irregularities increases, the average inclination angle increases, and the irregularity interval decreases, resulting in a decrease in contrast.

When the number of domain structures is increased, the size of the domain structure is decreased, and when the number of domain structures is decreased, the size of the domain structure is increased.
Examples of a method for adjusting the number of domain structures include a method for adjusting the film thickness of the optical functional layer. More specifically, increasing the film thickness of the optical functional layer increases the domain structure, thereby reducing the number of domain structures, and decreasing the film thickness of the optical functional layer decreases the domain structure, thereby reducing the number of domain structures. Will increase.

By adjusting the film thickness D (μm) of the optical functional layer and the average particle diameter r (μm) of the translucent fine particles so as to satisfy the relational expression of 3 × r <D ≦ 10 × r, It becomes easy to achieve both high contrast. It is more preferable that 3.5 × r ≦ D ≦ 9 × r, and it is particularly preferable that 4 × r ≦ D ≦ 8 × r. When the lower limit value of D is 3 × r or less, the uneven shape on the surface of the optical functional layer becomes small, and the antiglare property is insufficient. When the upper limit value of D is more than 10 × r, the optical laminate is likely to be curled.

The domain structure formed by agglomeration of translucent fine particles preferably has a diameter (either a major axis or a minor axis) in the range of 50 to 100 μm.
Since the surface irregularities formed by the domain structure within the range easily scatter incident light, the antiglare property is improved.

The domain structure has an arbitrary shape. Examples of the shape of the domain structure include a circular shape, an oval shape, an O shape, a U shape, an L shape, or a polygon shape obtained by combining these shapes. Adjacent domain structures each independently have an arbitrary shape.

The optical functional layer constituting the present invention may be laminated on the translucent substrate directly or via another layer, and may be laminated on one side or both sides of the translucent substrate. Furthermore, the optical layered body may have other layers. Other layers include, for example, a light diffusing layer, an antifouling layer, a polarizing substrate, a low reflection layer, another function-imparting layer (for example, an antistatic layer, an ultraviolet / near infrared (NIR) absorption layer, a neon cut layer, an electromagnetic wave Shield layer, hard coat layer). In addition, the position of the other layer is, for example, on the light-transmitting substrate opposite to the optical function layer in the case of a polarizing substrate, and on the optical function layer in the case of a low reflection layer. In the case of the functional provision layer, it is the lower layer of the optical functional layer. A laminate in which a polarizing substrate, a translucent substrate, and an optical functional layer are laminated can be used as a polarizing plate. In addition, the polarizing substrate, the translucent substrate, and the optical functional layer may be directly laminated, or may be laminated via other layers such as an adhesive layer.

<Method for forming domain structure>
The domain structure can be produced by utilizing convection associated with aggregation of light-transmitting fine particles. Specifically, a solution (paint) containing a resin component, translucent fine particles, and a solvent is applied onto a translucent substrate, and a drying process that generates convection as the solvent evaporates, and the dried coating film is cured. It can be manufactured through a curing process. 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) By using convection and aggregation together, first, a convection domain is generated in the coated layer after coating.
(2) Next, aggregation occurs in each convection domain, and the structure of the aggregation grows with time, but the growth of aggregation stops at the convection domain wall.
(3) As a result, the space is controlled according to the size and arrangement of the convection domain, and a domain structure associated with the aggregated structure is formed.
In the surface unevenness, a portion where the surface protrusion is formed forms a domain structure. The surface unevenness associated with the domain structure in the present invention has an average inclination angle smaller than that of a surface unevenness created using conventional fine particles, which is advantageous in that light diffusion on the surface is reduced and high contrast performance is exhibited.
Hereinafter, materials that can be preferably used for each layer constituting the present invention will be described.

<Translucent substrate>
The translucent substrate according to the best mode is not particularly limited as long as it is translucent, and glass such as quartz glass and soda glass can be used, but PET, TAC, polyethylene naphthalate (PEN), poly Methyl methacrylate (PMMA), polycarbonate (PC), polyimide (PI), polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), cycloolefin copolymer (COC), norbornene-containing resin, Various resin films such as 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 can be formed by applying a paint containing a resin component, translucent fine particles and a solvent on a translucent substrate, volatilizing the solvent, and then curing the resin component. The optical functional layer may contain other optional components.
The thickness of the optical functional layer is preferably in the range of 2.0 to 15.0 μm, more preferably in the range of 3.0 to 10.0 μm, and still more preferably in the range of 4.0 to 9.0 μm. is there. When the optical functional layer is thinner than 2.0 μm, curing failure due to oxygen inhibition occurs at the time of ultraviolet curing, and the wear resistance of the optical functional layer is likely to deteriorate. When the optical functional layer is thicker than 15.0 μm, curling due to curing shrinkage of the optical functional layer, generation of microcracks, decrease in adhesion to the translucent substrate, and 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.
It can be used as an antiglare layer by forming an uneven surface structure on the optical functional layer. Moreover, the laminated body which has an anti-glare layer on a translucent base | substrate can be used as an anti-glare film.

(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. In addition, a composition in which prepolymers are used alone or appropriately mixed is 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. 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. Further, by increasing the blending amount of the ionizing radiation curable fluorinated acrylate, the size of the domain structure can be increased and the number of domain structures per unit area can be decreased. The proportion of ionizing radiation curable fluorinated acrylate contained in the optical functional layer is not particularly limited, but is 0.05 to 50% by mass in 100 parts by mass of the total mass of solid components in the resin composition constituting the optical functional layer. Is preferable, and 0.2 to 20% by mass is more preferable. When the blending amount of the ionizing radiation curable fluorinated acrylate is less than 0.05% by mass, the water repellent effect and the slipping property are lowered, and the scratch resistance, antifouling property and chemical resistance are deteriorated. When the blending amount of the ionizing radiation curable fluorinated acrylate is more than 50% by mass, the film forming property may be deteriorated.
Here, solid contents in the optical functional layer such as ionizing radiation curable resin and translucent fine particles are collectively referred to as “resin composition”. In addition, components such as an ionizing radiation curable fluorinated acrylate and an antistatic agent may optionally be included.

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 (xxxi) 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 has a function of uniforming the tension on the surface of the coating film and correcting defects before forming the coating film, and a substance having a lower interfacial tension and surface tension than the ionizing radiation curable resin is used.

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 99.9 mass%. If it is less than 50% by mass, there is a problem that sufficient hardness cannot be obtained.

(Translucent fine particles)
As the translucent fine particles, organic translucent resin fine particles made of acrylic resin, polystyrene resin, styrene-acrylic copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, polyfluorinated ethylene resin, etc. Inorganic light-transmitting fine particles such as silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, and antimony oxide can be used. The refractive index of the translucent 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 translucent substrate or the resin matrix becomes large. Too much, 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 0.5 to 5 μm, and more preferably 1.0 to 3 μm. When the particle size is smaller than 0.5 μm, the antiglare property is deteriorated, and when it is larger than 5 μm, it is not preferable because glare occurs and the surface unevenness becomes too large and the surface becomes whitish. Further, the ratio of the light-transmitting fine particles contained in the optical functional layer is not particularly limited. However, 0.1 to 20% by mass with respect to 100 parts by mass of the resin composition is a characteristic such as an antiglare function and glare. Is preferable, 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. The “average particle diameter” refers to an average value of the diameters of 100 particles actually measured with an electron microscope.

(solvent)
As the solvent, a solvent that can dissolve the resin component contained in the resin composition well and disperse the translucent fine particles is used.
In particular, the solvent (solvent) for forming surface irregularities for forming the domain structure preferably contains a first solvent and a second solvent.
By adding the first solvent and the second solvent, a surface uneven shape based on the domain structure can be created on the surface of the optical functional layer by utilizing aggregation and convection.

A 1st solvent means what can disperse | distribute translucent fine particles favorably. Although the 1st solvent which can be used changes with kinds of translucent fine particles, for example, when PMMA microparticles are used as translucent fine particles, as the 1st solvent, aromatic solvents, such as toluene, methyl ethyl ketone (MEK), A ketone solvent such as methyl isobutyl ketone (MIBK) can be used. These first solvents may be used alone or in combination.

A 2nd solvent means what can aggregate a translucent fine particle moderately.
Although the 2nd solvent which can be used changes with kinds of translucent fine particles, for example, when PMMA microparticles are used as translucent microparticles, water, methanol, ethanol, etc. can be used as the 2nd solvent. These second solvents may be used alone or in combination.

Here, it is preferable to mix and use the resin component, the translucent fine particles, the first solvent and the second solvent. After this mixed paint is applied onto a light-transmitting substrate to form a coating layer, convection is likely to occur in the coating layer when the first and second solvents contained in the coating layer are volatilized. . This convection forms a domain structure on the surface of the coating layer. After the domain structure is formed, the domain structure can be formed in the optical functional layer by curing the resin contained in the paint. In addition, when forming the said application layer, it is made for the range of this invention to include the relationship between the film thickness of an optical function layer after hardening, and an average particle diameter. The optical functional layer formed by mixing the first solvent and the second solvent as described above is preferable because surface irregularities for obtaining antiglare properties are easily formed.

(Antistatic agent)
The optical functional layer may contain an antistatic agent (the antistatic agent may be referred to as a conductive agent or a conductive material). 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.

Moreover, electroconductive fine particles are mentioned. 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 fine particles refer to those having a so-called submicron size of 1 micron or less, and preferably those having 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 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 organic sulfonic acid or iron chloride can also 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 and polydiacetylene alkyl group-substituted products.

(Polarizing substrate)
In the present invention, a polarizing substrate may be laminated on a light transmitting substrate opposite to the optical functional layer. By laminating the optical functional layer, the translucent substrate, and the polarizing substrate, a polarizing plate can be obtained. These layers may be laminated directly or via other layers such as an adhesive layer. Here, the polarizing substrate uses a light-absorbing polarizing film that transmits only specific polarized light and absorbs other light, or a light reflective polarizing film that transmits only specific polarized light and reflects other light. I can do it. As the light-absorbing polarizing film, 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 the light reflection type polarizing film, 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. .

<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. The optical layered body of the present invention preferably has the following properties and functions.

(Haze)
The total haze of the optical layered body according to the best mode is preferably 3 to 13, more preferably 4 to 10.5, and still more preferably 5 to 9. .

(Total light transmittance)
The total light transmittance of the optical layered body is preferably 90% or more, more preferably 90.5% or more, and further preferably 91% or more.

(Image clarity)
The image clarity of the optical laminate before saponification is preferably 0 to 90%, more preferably 5 to 80%, and more preferably 10 to 77 with an optical comb width of 0.5 mm. More preferably, it is 5%.

(Glitter)
The glare of the optical laminate is bonded to the surface of several liquid crystal displays with different resolutions through a colorless and transparent adhesive layer on the surface opposite to the surface on which the optical laminate is formed, photographed with a CCD camera, and variations in image brightness. Can be judged by the presence or absence. It is preferable that the glare cannot be confirmed on a display with a higher resolution, and it is preferable that the liquid crystal display with a resolution of 101 to 140 ppi has no glare.

(Average tilt angle)
The optical layered body of the present invention has a fine uneven shape on the surface of the optical functional layer. Here, the fine concavo-convex shape preferably has an average inclination angle calculated from an average inclination obtained according to ASME 95 in the range of 0.2 ° to 1.4 °, more preferably 0.25 ° to It is 1.2 °, more preferably 0.25 ° to 1.0 °. When the average inclination angle is less than 0.2 °, the antiglare property is deteriorated, and when the average inclination angle exceeds 1.4 °, the contrast is deteriorated, so that it is not suitable for the optical laminate used for the display surface.

(Arithmetic mean roughness)
In the optical layered body of the present invention, the arithmetic average roughness Ra is preferably 0.05 μm to 0.2 μm, and preferably 0.05 μm to 0.15 μm, as the fine uneven shape of the optical functional layer. More preferably, it is 0.05 micrometer-0.10 micrometer especially preferable. When the arithmetic average roughness Ra is less than 0.05 μm, the antiglare property of the optical laminate is insufficient. When the arithmetic average roughness Ra is more than 0.2 μm, the contrast of the optical laminate is deteriorated.

(Average unevenness)
In this invention, it is preferable that the uneven | corrugated average space | interval Sm is 50 micrometers-200 micrometers. When Sm is less than 50 μm, sufficient contrast cannot be obtained, and when Sm exceeds 200 μm, the antiglare property is lowered, so that it is not suitable for an optical laminate used for a display surface.

(Macbeth concentration)
The Macbeth reflection density of the optical layered body of the present invention indicates that the larger the value measured in a state where the surface of the light-transmitting substrate of the optical film opposite to the resin layer is black, the black. The Macbeth reflection density value is preferably 3.2 or more. When an optical film is used on the surface of a display or the like, a large difference in white display is rarely seen. Therefore, in order to increase the contrast, it is necessary to emphasize blackness during black display. When the Macbeth reflection density is less than 3.2, high contrast is insufficient.

(Glossiness)
The 60 ° glossiness of the optical laminate of the present invention is preferably in the range of 100 to 130. When the 60 ° gloss is greater than 130, the antiglare property is lowered, which is not preferable. On the other hand, when the 60 ° glossiness is less than 100, the antiglare property is good, but it is not preferable because the light room contrast becomes low due to strong light scattering on the surface.

<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.

(Production Example 1) Synthesis of ionizing radiation curable fluorinated acrylate solution A In a 500 ml reaction flask, air bubbling was performed on 100 ml of MIBK (methyl isobutyl ketone) in 22.2 g (0.1 mol) of isophorone diisocyanate. Then, a solution of 59.6 g (0.20 mol) of pentaerythritol triacrylate in 50 ml of MIBK was added dropwise at 25 ° C. After completion of dropping, 0.3 g of dibutyltin dilaurate was added, and the mixture was further stirred with heating at 70 ° C. for 4 hours. After completion of the reaction, the reaction solution was washed with 100 ml of 5% hydrochloric acid. After separating the organic layer, the solvent was distilled off under reduced pressure at 40 ° C. or less to obtain 80.5 g of a colorless transparent viscous liquid urethane acrylate. Into a 200 ml reaction flask, 40.8 g (0.05 mol) of the prepared urethane acrylate, 71.9 g (0.15 mol) of perfluorooctylethyl mercaptan, and 60 g of MIBK were added to make uniform. To this mixed solution, 1.0 g of triethylamine was gradually added at 25 ° C. After the addition was completed, the mixture was further stirred at 50 ° C. for 3 hours. After completion of the reaction, triethylamine is distilled off under reduced pressure using an evaporator under conditions of 50 ° C. or lower, and further dried with a vacuum pump, thereby containing a fluorinated alkyl group-containing urethane acrylate represented by Structural Formula 1, and an acryloyl group. An ionizing radiation curable fluorinated acrylate A liquid comprising a mixture further containing a compound different from the structural formula 1 in the position of the addition reaction between and perfluorooctylethyl mercaptan was obtained.

Production Example 2 Synthesis of ATO-containing UV-curable resin B solution A mixed solution in which 130 g of potassium stannate and 30 g of potassium antimonyl tartrate were dissolved in 400 g of pure water was prepared. This prepared solution was added to 1000 g of pure water in which 1.0 g of ammonium nitrate and 12 g of 15% ammonia water were dissolved at 60 ° C. over 12 hours for hydrolysis. At this time, a 10% nitric acid solution was simultaneously added so as to keep the pH at 9.0. The generated precipitate was washed by filtration and then dispersed again in water to prepare a metal oxide precursor hydroxide dispersion having a solid content concentration of 20% by mass. This dispersion was spray-dried at a temperature of 100 ° C. to prepare a metal oxide precursor hydroxide powder. This powder was heat-treated at 550 ° C. for 2 hours in an air atmosphere to obtain Sb-doped tin oxide (ATO) powder.
60 g of this powder was dispersed in 140 g of an aqueous potassium hydroxide solution having a concentration of 4.3% by mass, and the dispersion was pulverized with a sand mill for 3 hours while maintaining the dispersion at 30 ° C. to prepare a sol. Next, this sol was subjected to dealkalization ion treatment with an ion exchange resin until the pH became 3.0, and then pure water was added to prepare an ATO dispersion having a solid content concentration of 20% by mass. The PH of this ATO dispersion was 3.3. The average particle diameter of the ATO fine particles was 10 nm.
Next, 100 g of ATO dispersion was adjusted to 25 ° C., 4.0 g of tetraethoxysilane (manufactured by Tama Chemical Co., Ltd .: normal ethyl silicate, SiO 2 concentration 28.8% by mass) was added in 3 minutes, and then stirred for 30 minutes. Went. Thereafter, 100 g of ethanol was added over 1 minute, the temperature was raised to 50 ° C. over 30 minutes, and a heat treatment was performed for 15 hours. The solid content concentration at this time was 10% by mass.
Subsequently, water and ethanol as a dispersion medium were replaced with ethanol using an ultrafiltration membrane, and an ATO dispersion liquid surface-treated with an organosilicon compound having a solid content concentration of 30% by mass was prepared.
13.1 g of ATO dispersion surface-treated with this organosilicon compound, 25.6 g of pentaerythritol triacrylate (PE-3A manufactured by Kyoeisha Chemical Co., Ltd.), 17.1 g of urethane acrylate (UA306I manufactured by Kyoeisha Chemical Co., Ltd.), photopolymerization initiator (Ciba Japan Irgacure 184) 2.5 g, ethanol 34.2 g, and toluene 7.5 g were mixed and mixed in a paint shaker for 30 minutes to obtain an ATO-containing UV curable resin B liquid having a solid content concentration of 49 mass%. .

  A coating material for forming an optical functional layer obtained by stirring the predetermined mixture shown in Table 1 containing the ionizing radiation curable fluorinated acrylate A liquid and the ATO-containing ultraviolet curable resin B liquid with a disper for 30 minutes. The film was applied on one side of a transparent TAC film (manufactured by FUJIFILM; TD80UL) having a film thickness of 80 μm and a total light transmittance of 92% by a roll coating method (line speed; 20 m / min), and 30 to 50 ° C. After 20 seconds of preliminary drying at 100 ° C. for 1 minute, irradiation with ultraviolet rays in a nitrogen atmosphere (nitrogen gas replacement) (lamp; condensing high-pressure mercury lamp, lamp output: 120 W / cm, number of lamps: 4 lamps, The coating film was cured by performing an irradiation distance of 20 cm. Thus, the optical laminated body of Example 1 which has an optical function layer with a thickness of 7.3 micrometers was obtained.

  The optical functional layer-forming coating material was changed in the same manner as in Example 1 except that the ionizing radiation curable fluorinated acrylate A liquid and the ATO-containing ultraviolet curable resin B liquid were changed to the predetermined mixed liquid described in Table 1. An optical layered body of Example 2 having an optical functional layer with a thickness of 7.2 μm was obtained.

  An optical functional layer having a thickness of 6.0 μm was formed in the same manner as in Example 1 except that the coating for forming the optical functional layer was changed to the predetermined mixed liquid described in Table 1 containing the ATO-containing ultraviolet curable resin B liquid. The optical laminated body of Example 3 which has was obtained.

  An optical laminate of Example 4 was obtained in the same manner as in Example 2 except that the optical functional layer had a thickness of 11.0 μm.

[Comparative Example 1]
An optical function having a thickness of 3.5 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 solution shown in Table 1 containing amorphous silica having an average particle size of 4.1 μm. An optical laminate of Comparative Example 1 having a layer was obtained.

[Comparative Example 2]
The coating for forming an optical functional layer was changed to the predetermined mixed solution described in Table 1 including the ionizing radiation curable fluorinated acrylate A liquid and the ATO-containing ultraviolet curable resin B liquid, and not including translucent fine particles. In the same manner as in Example 1, an optical laminate of Comparative Example 2 having an optical functional layer having a thickness of 7.3 μm was obtained.

[Comparative Example 3]
The coating material for forming the optical functional layer was changed to the predetermined mixed solution described in Table 1 including the ionizing radiation curable fluorinated acrylate A liquid, the ATO-containing ultraviolet curable resin B liquid, and the PMMA fine particles having an average particle diameter of 5 μm. Except for the above, an optical layered body of Comparative Example 3 having an optical functional layer with a thickness of 6.7 μm was obtained in the same manner as Example 1.

[Comparative Example 4]
An optical laminate of Comparative Example 4 was obtained in the same manner as in Example 2 except that the optical functional layer had a thickness of 4.0 μm.

<Evaluation method>
Next, the following items were evaluated for the optical laminates of Examples and Comparative Examples.

(Number of domains)
The number of domains was photographed with an optical microscope at a magnification of 50 times, and the number of domains present in a 0.1 mm ² frame of the photograph was visually measured. In addition, about the domain which exists over the inside and outside of a frame which shows 0.1 mm < ² >, it counted only when it is recognized visually that the area occupies half or more in the frame. After measuring the number of domains existing in the 0.1 mm ² frame as described above, the number of domains existing per 1 mm ² was calculated.
Optical microscope: OLYMPUS BX60
Camera: NIKOON COOLPIX E995
Shooting mode: Transparent
Optical laminates of Examples and Comparative Examples are shown in the drawings (Example 1 is FIG. 2, Example 2 is FIG. 3, Example 3 is FIG. 4, Example 4 is FIG. 5, Comparative Example 1 is FIG. 6, Comparative Example 3 is FIG. 7 and Comparative Example 4 is FIG. 8).
The optical layered body of Comparative Example 2 was not photographed because a domain structure was not formed because the thickness of the optical functional layer was thin relative to the average particle diameter.

(Total light transmittance)
The total light transmittance was measured using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku) in accordance with JIS K7105.

(Haze value)
The haze value was measured according to JIS K7105 using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku). In addition, the haze in a table | surface is a value of all haze.

(Arithmetic average roughness, average interval of unevenness)
Arithmetic average roughness Ra and unevenness average interval Sm were measured using a surface roughness measuring instrument (trade name: Surfcorder SE1700α, manufactured by Kosaka Laboratories) in accordance with JIS B0601-1994.

(Average tilt angle)
The average inclination angle was determined according to ASME95 using a surface roughness measuring instrument (trade name: Surfcorder SE1700α, manufactured by Kosaka Laboratories), and the average inclination angle was calculated according to the following formula.
Average inclination angle = tan ⁻¹ (average inclination)

(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 evaluated as “◯” when the image sharpness value was 0 to 80, “Δ” when 81 to 90, and “x” when 91 to 100.

(Glitter)
The glare is a liquid crystal display (trade name: LC-32GD4, manufactured by Sharp Corporation) with a resolution of 50 ppi on the surface opposite to the optical laminate-forming surface of each example and each comparative example via a colorless and transparent adhesive layer. Liquid crystal display (trade name: LL-T1620-B, manufactured by Sharp), liquid crystal display with resolution of 120 ppi (trade name: LC-37GX1W, manufactured by Sharp), and liquid crystal display with resolution of 140 ppi (trade name) : VGN-TX72B, manufactured by Sony Corporation, a liquid crystal display with a resolution of 150 ppi (trade name: nw8240-PM780, manufactured by Hewlett-Packard Japan), and a liquid crystal display with a resolution of 200 ppi (trade name: PC-CV50FW, manufactured by Sharp Corporation) ) Are attached to the screen surface, and the LCD After the play is displayed in green, the resolution value when the brightness variation is not 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 0. When it was ˜50 ppi, it was marked as Δ when it was 51 to 100 ppi, ◯ when it was 101 to 140 ppi, and ◎ when it was 141 to 200 ppi.

(Light room contrast)
Bright room contrast is a liquid crystal display device (trade name: LC-37GX1W, manufactured by Sharp Corporation) through a colorless and transparent adhesive layer on the surface opposite to the surface on which the optical functional layer is formed in the optical laminates of Examples and Comparative Examples. Pasted on the screen surface of the liquid crystal display device, the liquid crystal display surface was illuminated with a fluorescent lamp (trade name: HH4125GL, manufactured by National Corporation) from the direction 60 ° above the front of the liquid crystal display device screen, and then the liquid crystal display The luminance when the device is in white display and black display is measured with a color luminance meter (trade name: BM-5A, manufactured by Topcon Corporation), and the resulting luminance (cd / m ² ) and white display in black display are obtained. When the luminance (cd / m ² ) at the time was calculated by the following formula, the value was 800 when the value was 800 or less, and when the value was 801 or more, the result was ○.
Contrast = Brightness of white display / Brightness of black display

(Dark room contrast)
The dark room contrast is that of the liquid crystal display device (trade name: LC-37GX1W, manufactured by Sharp Corporation) through a colorless and transparent adhesive layer on the surface opposite to the surface on which the optical functional layer is formed in the optical laminates of Examples and Comparative Examples. The black display was obtained by measuring the luminance when the liquid crystal display device was set to white display and black display under dark room conditions with a color luminance meter (trade name: BM-5A, manufactured by Topcon Corporation). value when calculated in the luminance (cd / ^{m 2)} and the white display of the luminance (cd / ^{m 2)} the following equation when there is, × when 900-1100, when 1,101 to 1300 △, 1301 to In the case of 1500, it was rated as “good”.
Contrast = Brightness of white display / Brightness of black display

(Macbeth concentration)
The Macbeth reflection density is in accordance with JIS K 7654, using a Macbeth reflection densitometer (trade name: RD-914, manufactured by Sakata Engineering Co., Ltd.) and the resin layer of the translucent substrate of the optical laminates of Examples and Comparative Examples The opposite surface was black-coated with magic ink (registered trademark), and then Macbeth reflection density on the surface of the resin layer was measured.

(Glossiness)
The glossiness was 60 ° specular glossiness measured using a gloss meter (trade name: VG2000, Nippon Denshoku Co., Ltd.) according to JIS Z8741.

  The obtained results are shown in Table 2. In addition, the data in a table | surface are the results of measuring the optical laminated body before performing saponification unless there is particular description.

As shown in Table 2, in the optical layered body of each example, the film thickness D of the optical functional layer and the average particle diameter r of the translucent fine particles contained in the optical functional layer are 3 × r <D ≦ In order to satisfy the relational expression of 10 × r, antiglare property and high contrast (bright room and dark room) could be achieved. In particular, the optical laminates of Examples 1 to 3 exhibited an effect on glare as well as antiglare properties and high contrast.
On the other hand, since the optical laminated body of each comparative example did not satisfy | fill the said relational expression 3 * r <D <= 10 * r, it was not able to make anti-glare property and high contrast (light room and dark room) compatible.

DESCRIPTION OF SYMBOLS 1 Optical laminated body 10 Translucent base | substrate 20 Optical functional layer 21 Domain structure 22 Non-domain structure

Claims (10)

A translucent substrate and at least one optical functional layer provided on the translucent substrate, the optical functional layer having a domain structure, and the film thickness D of the optical functional layer and the optical function An optical laminate having an average particle diameter r of translucent fine particles contained in a layer in a range represented by a relational expression of 3 × r <D ≦ 10 × r. 2. The optical layered body according to claim 1, wherein a thickness D of the optical functional layer is in a range of 2 μm to 15 μm. 3. The optical laminate according to claim 1, wherein an average particle diameter r of the light-transmitting fine particles contained in the optical functional layer is in the range of 0.5 μm to 5.0 μm. The domain structure formed in the optical function layer, the optical laminate according to any one of claims 1 to 3, characterized in that the range 1 mm 20 pieces 1000 pieces per ^2. The optical laminated body according to any one of claims 1 to 4, wherein an arithmetic average roughness Ra on the surface of the optical functional layer is in a range of 0.05 µm to 0.20 µm. The optical laminated body according to any one of claims 1 to 5, wherein an unevenness average interval Sm on the surface of the optical functional layer is in a range of 50 µm to 200 µm. The optical laminate according to any one of claims 1 to 6, wherein an average inclination angle on the surface of the optical functional layer is in a range of 0.2 ° to 1.4 °. A polarizing plate comprising the optical layered body according to claim 1. A display device comprising the optical layered body according to claim 1. A coating material in which a resin component, a light-transmitting fine particle, a first solvent, and a second solvent are mixed is applied onto a light-transmitting substrate to form a coating layer, and the first and second layers included in the coating layer are formed. When the solvent is volatilized, a convection is generated in the coating layer to form a domain structure, and then the resin component contained in the paint is cured to form an optical functional layer. The method for producing an optical laminate, wherein an average particle diameter r of translucent fine particles contained in the optical functional layer satisfies a relational expression of 3 × r <D ≦ 10 × r.

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