JP2010079111A - Optical layered product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical layered product which includes high scratch resistance even when using an organic filler. <P>SOLUTION: In the optical layered product made by disposing at least an optically functional layer on one surface or both surfaces of a transmissive base directly or via the other layer, the optically functional layer includes a transmissive resin as a matrix, the transmissive organic filler dispersed into the transmissive resin and metal oxide fine particles the particle size of which is 1 to 100 nm and a compounding amount is 0.1 to 10 wt.%, wherein the metal oxide fine particles are unevenly distributed on the surface of the transmissive organic filler. <P>COPYRIGHT: (C)2010,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 more particularly to an optical laminate for improving the visibility of a screen.

  In recent years, displays such as LCDs and PDPs have been developed, and products of various sizes have been manufactured and sold for many applications from mobile phones to large-sized televisions.

  In these displays, the visibility of the image is hindered by reflection of room lighting such as a fluorescent lamp, sunlight from a window, shadow of an operator, etc. on the display device surface. Therefore, on the display surface, in order to improve the visibility of the image, the surface reflection light is diffused, regular reflection of external light is suppressed, and reflection of the external environment can be prevented (having anti-glare property) A functional film such as an antiglare film having a concavo-convex structure is provided on the outermost surface (conventional AG).

  These functional films have an antiglare 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”). One layer provided and one obtained by laminating a low refractive index layer on a light diffusing layer are generally manufactured and sold, and development of a functional film that provides a desired function by a combination of layer configurations is in progress.

  However, in recent years, the display has been increased in size, definition, and contrast, and there has been a demand for improvement in performance required for functional films.

  When an anti-glare film is used on the outermost surface, when used in a bright room, the black display image becomes whitish due to the diffusion of light, and there is a problem that 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).

  In order to achieve high contrast, a method of providing a single or multiple low reflection layers on the antiglare film has been used (AG with a low reflection layer).

  On the other hand, when an anti-glare film is used on the outermost surface, there is a problem that glare (a portion with high or low brightness) that appears to be caused by a fine uneven structure is generated on the surface and lowers visibility. This glare is likely to occur with the refinement of the pixels accompanying the increase in the number of pixels of the display and the improvement of the display technology such as the pixel division method, and an antiglare film having an effect of preventing glare is demanded ( High definition AG).

In order to achieve the glare prevention effect, as in Patent Document 1, the average crest distance (Sm), center line average surface roughness (Ra), and ten-point average surface roughness (Rz) of the functional film surface are finely defined. As a method for adjusting the balance of the reflection of external light on the screen, the glare phenomenon and the whiteness, the ranges of the surface haze and the internal haze are finely defined as in Patent Document 2 and Patent Document 3. Methods are also being developed. For this reason, in the design of a light diffusive sheet used for a high-definition LCD, the internal diffusibility for achieving a glare prevention effect and the surface diffusivity for controlling the blurring effect are performed.
JP 2002-196117 A Japanese Patent Laid-Open No. 11-305010 JP 2002-267818 A

  Conventionally, silica has generally been used as a light-transmitting filler, but as demands on display image quality (contrast, anti-glare properties, and glare) become stricter, an organic material that can easily manipulate the refractive index, particle size, and the like. System fillers have come to be preferred. Since this translucent organic filler is generally softer than inorganic fillers such as silica, the surface portion that is convexly formed with the filler (the resin swells over the filler) is selectively rubbed. There have been problems such as shaving, scratching, and a difference in contrast with the surrounding area. Therefore, an object of the present invention is to provide an optical laminate having high scratch resistance while satisfying required properties for contrast, antiglare properties and glare even when an organic filler is used.

The present invention (1) is an optical laminate in which at least an optical functional layer is provided on one side or both sides of a translucent substrate, directly or via another layer,
The optical functional layer is
A translucent resin as a matrix;
A translucent organic filler dispersed in the translucent resin;
Metal oxide fine particles having a particle size of 1 to 100 nm and a blending amount of 0.1 to 10% by weight,
Here, the metal oxide fine particles are unevenly distributed on the surface of the translucent organic filler.

The present invention (1-2) is an optical laminate in which at least an optical functional layer is provided directly or via another layer on one side or both sides of a translucent substrate,
The optical functional layer is
After applying a paint formed by mixing at least an energy curable resin composition, a translucent organic filler, and a metal oxide sol directly or via another layer to one or both sides of the translucent substrate, energy is applied. It is a layer formed by hardening the said energy curable resin composition by applying, It is an optical laminated body characterized by the above-mentioned.

The present invention (1-3) is an optical laminate in which at least an optical functional layer is provided on one side or both sides of a translucent substrate, directly or via another layer,
The optical functional layer is
A translucent resin as a matrix;
A translucent organic filler dispersed in the translucent resin;
Metal oxide fine particles having a particle size in the range of 1 to 100 nm,
Here, the optical laminated body is characterized in that the metal oxide fine particles are coated on the entire surface of the translucent organic filler.

  The present invention (2) is the optical laminate according to the invention (1), wherein the metal oxide fine particles are alumina fine particles.

In the present invention (3), at least the energy curable resin composition, the translucent organic filler, and the metal oxide sol are mixed on one side or both sides of the translucent substrate directly or via another layer. An application process for applying paint;
After the said application process, it is a manufacturing method of an optical laminated body including the hardening process of applying an energy and hardening the said energy curable resin composition, and forming an optical functional layer.

  This invention (4) is a manufacturing method of the optical laminated body of the said invention (3) whose said metal oxide sol is an alumina sol.

  Here, the definitions of each term in the claims and the specification will be described. “On the surface of the translucent organic filler” means not only when the metal oxide fine particles adhere to the surface of the translucent organic filler but also the metal oxide fine particles adhere to the surface of the translucent organic filler. Although it is not present, it indicates when it is present near the surface of the translucent organic filler (within a distance of up to 10% of the diameter from the surface). “Energy” refers to energy rays (for example, electron beams or ultraviolet rays) or heat. “Applying paint” is a concept including application, spraying, dipping and the like.

  According to the present invention (1), the surface of the translucent organic filler is protected with the metal oxide fine particles so that the filler is hard and tough, so that the damage due to the deformation of the filler is prevented and the scratch resistance is improved. There is an effect of improving. In addition, since the metal oxide fine particles are unevenly distributed on the surface of the translucent organic filler, the adhesion between the translucent organic filler and the translucent resin is increased, so that the scratch resistance is further improved. Furthermore, since the metal oxide fine particles have a small particle size, the optical influence can be minimized, and there is an effect that problems such as haze increase, transmittance decrease, and contrast decrease are less likely to occur.

  According to the present invention (2), in addition to the above effects, the scratch resistance and surface hardness are greatly improved.

  According to the present invention (3) and (4), by using a metal oxide sol as the metal oxide fine particle source, compatibility with the resin is improved, so that it becomes easy to form a paint. In addition, since the metal oxide fine particles are less likely to aggregate, an optical function can be imparted uniformly.

  First, each component of the optical laminated body which concerns on this best form is explained in full detail. The optical layered body according to the best mode essentially has an optical functional layer containing at least translucent fine particles (translucent organic filler) on one or both sides of the translucent substrate. Furthermore, the optical layered body according to the best mode includes a low reflection layer, an antifouling layer, an antistatic layer, an infrared reflection (NIR) layer (on the optical layered body or between the translucent substrate and the optical layered body). An infrared cut layer) and a polarizing layer. Hereinafter, the translucent substrate and the optical functional layer which are essential layers will be described, and then the optional layer will be described.

<< Translucent substrate >>
First, 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 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 Various resin films such as resin, polyethersulfone, cellophane, and aromatic polyamide can be suitably used. In addition, when using for PDP and LCD, PET and a TAC film are more preferable.

  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.

  Also, by performing surface treatment such as alkali treatment, corona treatment, plasma treatment, sputtering treatment, surface treatment such as surfactant, silane coupling agent, or surface modification treatment such as Si deposition on the translucent substrate. Since the adhesion between the translucent substrate and the optical functional layer can be improved, the scratch resistance in the optical functional layer is improved.

<Translucent resin>
Next, the optical functional layer according to the best mode will be described in detail. The optical functional layer according to the best mode has a configuration in which translucent fine particles (translucent organic filler) and metal oxide fine particles are dispersed in a translucent resin. Here, the “translucent resin” is a total solid component excluding translucent fine particles in the paint (matrix component). The translucent resin is preferably formed by curing an energy curable resin that is cured by energy such as heat or radiation with energy, and is formed by curing the radiation curable resin composition with radiation. Although it is more preferable that it is, it is not specifically limited. Here, the radiation curable resin composition constituting the translucent resin includes radical polymerizable functional groups such as acryloyl group, methacryloyl group, acryloyloxy group, methacryloyloxy group, epoxy group, vinyl ether group, oxetane group. The composition which mixed the monomer, oligomer, prepolymer which has cationic polymerizable functional groups, such as these independently or suitably was used. Examples of monomers include methyl acrylate, methyl methacrylate, methoxypolyethylene 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.

  The radiation curable resin composition can be cured by electron beam irradiation as it is, but in the case of curing by ultraviolet irradiation, it is necessary to add a photopolymerization initiator. The radiation used may be any of ultraviolet rays, visible rays, infrared rays, and electron beams. 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.

  In the best mode, in addition to the radiation curable resin composition, a polymer resin can be added and used as long as the polymerization and curing is not hindered. This polymer resin is a thermoplastic resin that is soluble in an organic solvent used in the resin layer coating described later, and specifically includes acrylic resins, alkyd resins, polyester resins, cellulose, cellulose derivatives, and the like. This resin preferably has an acidic functional group such as a carboxyl group, a phosphoric acid group, or a sulfonic acid group.

  In addition, additives such as a leveling agent, a thickener, and an antistatic agent can be used. 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 lower interfacial tension and surface tension than the radiation curable resin composition is used. The thickener has a function of imparting thixotropy to the radiation curable resin composition, and is effective in forming fine uneven shapes on the surface of the resin layer by preventing sedimentation of translucent fine particles and pigments. The thickener is not particularly limited, but for example, it is preferable to use synthetic mica. Furthermore, it is preferable to organically treat the surface of the thickener with a quaternary ammonium salt or the like. By performing the treatment, the affinity with the resin and the metal oxide is increased, the performance is improved, and the suitability for workability is also improved.

  The translucent resin in the optical functional layer is mainly composed of a cured product of the above-mentioned radiation curable resin composition. The organic solvent is volatilized and then cured by electron beam or ultraviolet irradiation. As the organic solvent used here, it is necessary to select a solvent suitable for dissolving the radiation curable resin composition. Specifically, in consideration of coating suitability such as wettability to a light-transmitting substrate, viscosity, and drying speed, an alcohol type, an ester type, a ketone type, an ether type, or an aromatic hydrocarbon is used alone or in combination. Solvents can be used.

《Dispersed component》
Next, in the present best mode, the light-transmitting organic filler and metal oxide fine particles that are essential are described in detail. In this best mode, the metal oxide fine particles are unevenly distributed (spread) near the surface of the light-transmitting organic filler. By having the said structure, the abrasion resistance of an optical laminated body improves. The term “unevenly distributed” in the claims and the present specification refers to a state in which the metal oxide is particularly unevenly distributed in the vicinity of the surface of the translucent organic filler, and the cross section of the optical functional layer is observed with a TEM. The number of metal oxide fine particles observed around the cross section near the center of the translucent organic filler per 1 μm of translucent organic filler cross section length ([observed around the translucent organic filler cross section (surface) The number of metal oxide fine particles] / [cross-sectional circumferential length of translucent organic filler]) is preferably 2 / μm or more, more preferably 5 / μm or more, and 10 / μm or more. Is more preferred. Although an upper limit is not specifically limited, For example, it is 100 pieces / micrometer or less. The number of fine particles is an average value of the cross section of 10 arbitrarily selected fine particles.

As the translucent organic filler contained in the translucent organic filler optical functional layer, for example, acrylic resin, polystyrene resin, styrene-acrylic copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, polyfluoroethylene Organic translucent fine particles made of a resin or the like can be used.

  Here, the translucent organic filler contained in the optical functional layer preferably has a refractive index difference of 0.05 or less and 0.03 or less with respect to the radiation curable translucent resin layer. Is more preferable, and it is more preferable that it is 0.01 or less. When the difference in refractive index between the radiation curable translucent resin layer and the translucent organic filler is larger than 0.05, the degree of light scattering becomes too large and the contribution to high contrast is reduced. The refractive index of the translucent organic filler is preferably 1.45 to 1.58, more preferably 1.50 to 1.57. “Refractive index” refers to a measured value according to JIS K-7142.

  Next, the particle size of the translucent organic filler is preferably 0.3 to 10 μm, and more preferably 1 to 5 μm. When the particle size is smaller than 0.3 μm, the antiglare property is lowered. When the particle size is larger than 10 μm, it is not preferable because glare occurs and the surface unevenness becomes too large and the surface becomes whitish. Furthermore, the particle size of the translucent organic filler is preferably 20 to 80% of the film thickness, and more preferably 30 to 70%. “Particle size” refers to the average value of the diameters of 100 particles measured with an electron microscope. Of the total number, the fine powder and coarse powder mixed in the production process of the fine particles are less than 5% (more preferably less than 1%). Although the ratio of the translucent fine particles in the translucent resin is not particularly limited, it is preferably 1 to 50% by weight of the solid component in the optical functional layer, and more preferably 5 to 10% by weight. Is preferred. When it is within this range, it is preferable for satisfying characteristics such as an antiglare function and glare, and it is easy to control the fine uneven shape and light diffusion on the surface of the optical functional layer.

Metal oxide fine particles Subsequently, examples of the metal oxide fine particles contained in the optical functional layer include alumina fine particles, zirconia fine particles, titania fine particles, aluminum hydroxide fine particles, tin oxide fine particles, zinc oxide, and cesium oxide. These fine particles are preferably coated with a resin. The metal oxide fine particles are preferably used in the form of a metal oxide sol such as alumina sol, zirconia sol, titania sol, aluminum hydroxide sol, tin oxide sol or the like. Of these, alumina sol is particularly preferable.

  Here, since the metal oxide fine particles contained in the optical functional layer have a remarkably small particle size and little optical influence, basically any refractive index may be used.

  Next, the particle size of the metal oxide fine particles is preferably 1 to 100 nm, and more preferably 5 to 50 nm. When the particle size is 1 nm or less, the production cost of the metal oxide fine particles and the metal oxide sol increases. Further, when the optical functional layer is formed, the metal oxide fine particles and the metal oxide sol are difficult to move in the layer, so that problems such as difficulty in uneven distribution occur. Further, when the particle diameter is 100 nm or more, haze increases, and the optical properties of the optical laminate such as transmittance and contrast are impaired. Here, “particle diameter” refers to the average value of the diameters of 100 particles actually measured with an electron microscope. Of the total number, the fine powder and coarse powder mixed in the production process of the fine particles are less than 5% (more preferably less than 1%). The compounding amount of the metal oxide fine particles needs to be 0.1 to 10% by weight of the solid component in the optical functional layer, more preferably 0.3 to 5.0% by weight, and 0.5 to 3. 0% by weight is more preferred. When the blending amount is smaller than the above range, scratch resistance is deteriorated. When the blending amount is large, the optical characteristics are hindered as described above.

  By increasing the affinity between the translucent organic filler and the metal oxide fine particles, uneven distribution is efficiently performed, and high scratch resistance can be obtained with a small amount. As a method for increasing the affinity, there is a method using a translucent organic filler copolymerized with a monomer having a functional group such as a carboxylic acid group or an OH group. There is also a method of performing surface modification treatment. The surface modification treatment will be described in detail later. In addition, there is a method of adding an intermediate agent having affinity to both the translucent organic filler and the metal oxide fine particles. In this case, as the intermediate agent, for example, synthetic mica, nonionic surfactant, anionic surfactant, leveling agent (for example, fluorine type) or the like can be used. Here, 0.1 to 10 weight% of the solid component in an optical function layer is suitable for content of an intermediate agent, and 0.2 to 0.5 weight% is more suitable.

<Surface modification treatment>
Next, the surface modification treatment will be described in detail. The production method of the metal oxide fine particles used here is not particularly limited, and may be obtained by an arbitrary method such as a gas phase method, a sol-gel method, a colloidal precipitation method, a molten metal spray oxidation method, or arc discharge.

  After preparing predetermined metal oxide fine particles as described above, it is preferable to perform a surface modification treatment on the metal oxide fine particles using a surface modifier. This surface modification treatment is performed by dispersing the metal oxide fine particles in a predetermined solvent, specifically an organic solvent, and adding the surface modifier to cause a condensation reaction. At this time, the solution subjected to the surface modification can be appropriately heated to a temperature not higher than the boiling point of the solvent, and a method such as ultrasonic wave, microbead mill, stirring, and high-pressure emulsification is used in the dispersion mixing. You can also. Moreover, in the said stirring, arbitrary things, such as a magnetic stirrer and a motor with a stirring blade, can be used according to a manufacturing scale. The surface modifier can be diluted in advance with an organic solvent.

  Although the said surface treating agent is not specifically limited, For example, organometallic compounds, such as a silane coupling agent, a silylating agent, a titanium coupling agent, alkyllithium, and alkylaluminum, can be mentioned. Of these, silane coupling agents and silylating agents are particularly preferred from the viewpoints of ease of use and cost. Here, the compounding amount of the surface treatment agent is preferably 0.1 to 10.0% by weight of the solid component in the metal oxide fine particles or metal oxide sol. If it is less than 0.1%, the effect is poor, and if it is more than 10.0%, the stability of the paint is impaired.

  A silane coupling agent has a structure in which an organic substituent having affinity or reactivity for organic substances is chemically bonded to a hydrolyzable silyl group having affinity or reactivity for inorganic materials. Silane compound. Examples of the hydrolyzable group bonded to silicon include an alkoxy group, a halogen, an acetoxy group, and an alkenoxy group. Usually, an alkoxy group, particularly a methoxy group and an ethoxy group are used.

  Examples of the organic substituent include an alkyl group, an aryl group, an amino group, a methacryl group, an acrylic group, a vinyl group, an epoxy group, and a mercapto group. Specifically, alkyltrichlorosilane, alkyltrialkoxysilane, alkyldialkoxychlorosilane, dialkylalkoxychlorosilane, trialkylchlorosilane, trialkylalkoxysilane, aryltrichlorosilane, aryltrialkoxysilane, diaryldichlorosilane, diaryldialkoxysilane, Triarylchlorosilane, triarylalkoxysilane, γ-aminopropyltrialkoxysilane, γ-aminopropylmethyldialkoxysilane, γ-ureidopropyltrialkoxysilane, γ-methacryloxypropyltrialkoxysilane, vinyltrialkoxysilane, vinyltri Acetoxysilane, vinyltrichlorosilane, γ-glycidoxypropyltrialkoxysilane, γ-glycy Carboxypropyl methyl dialkoxysilane, and the like can be exemplified (3,4 epoxycyclohexyl) ethyl trialkoxysilane, .gamma.-mercaptopropyl trialkoxysilane, .gamma.-chloropropyl trialkoxysilane.

  Examples of the silylating agent include trimethylsilylating agents, alkylsilanes, and allylsilanes. Examples of the trimethylsilylating agent include trimethylchlorosilane, hexamethyldisilazane, n-trimethylsilylimidazole, bis (trimethylsilyl) urea, trimethylsilylacetamide, bistrimethylsilylacetamide, trimethylsilyl isocyanate, trimethylmethoxysilane, and trimethylethoxysilane. Can do. Examples of the alkylsilanes include 1,6-bis (trimethoxysilyl) hexane, dimethylsilyl diisocyanate, and methylsilyltriinocyanate. Examples of allylsilanes include phenylsilyl triisocyanate.

  Further, as the solvent, it is desirable to use a solvent that can disperse the metal oxide fine particles and dissolve the surface modifier. When a solvent with low dispersibility is used, the metal oxide fine particles are aggregated, and when a solvent with low solubility is used, the modifier is separated. Specifically, it can be used by appropriately selecting from the solvents used in preparing the organosol described above.

<Removal and purification of free modifier>
Next, after the surface modification treatment is completed, the solvent in which the metal oxide fine particles remain is washed directly, and chemically bonded to the surface of the metal oxide fine particles to contribute to the surface modification. The free modifier is removed and purified. In the present invention, the free modifier is removed by directly washing the solvent without applying a technique such as drying or solid-liquid separation to the solvent in which the free modifier remains. Yes. Therefore, removal and purification of the free modifier can be performed efficiently.

<Structure of optical functional layer>
The film thickness of the optical functional layer is preferably in the range of 3 to 25 μm, more preferably in the range of 5 to 15 μm, and still more preferably in the range of 6 to 12 μm. When the film thickness is thinner than 3 μm, fine particles having different specific gravity cannot be sufficiently separated in the thickness direction. When it is thicker than 25 μm, curling occurs due to curing shrinkage of the optical functional layer, microcracks occur, adhesion to the translucent substrate decreases, and light transmission decreases. 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.

<Low reflection layer>
In this best mode, a low reflection layer can be provided on the optical functional layer in order to improve the contrast. In this case, the refractive index of the low reflective layer needs to be lower than the refractive index of the optical functional layer, and is preferably 1.45 or less. Examples of the material having these characteristics include LiF (refractive index n = 1.4), MgF ₂ (n = 1.4), 3NaF · AlF ₃ (n = 1.4), AlF ₃ (n = 1. 4), inorganic low reflection material in which inorganic material such as Na ₃ AlF ₆ (n = 1.33) is finely divided and contained in acrylic resin or epoxy resin, fluorine-based, silicone-based organic compound, Examples thereof include organic low reflection materials such as thermoplastic resins, thermosetting resins, and radiation curable resins. Among them, a fluorine-based fluorine-containing material is particularly preferable in terms of preventing contamination. The low reflective layer preferably has a critical surface tension of 20 dyne / cm or less. When the critical surface tension is larger than 20 dyne / cm, it becomes difficult to remove the dirt adhered to the low reflection layer.

  Examples of the fluorine-containing material include vinylidene fluoride copolymers, fluoroolefin / hydrocarbon copolymers, fluorine-containing epoxy resins, fluorine-containing epoxy acrylates, fluorine-containing silicones, which are easily dissolved in organic solvents. , Fluorine-containing alkoxysilanes, and the like. These can be used alone or in combination.

  Further, 2- (perfluorodecyl) ethyl methacrylate, 2- (perfluoro-7-methyloctyl) ethyl methacrylate, 3- (perfluoro-7-methyloctyl) -2-hydroxypropyl methacrylate, 2- (perfluoro- 9-methyldecyl) ethyl methacrylate, fluorine-containing methacrylate such as 3- (perfluoro-8-methyldecyl) -2-hydroxypropyl methacrylate, 3-perfluorooctyl-2-hydroxylpropyl acrylate, 2- (perfluorodecyl) ethyl acrylate , Fluorine-containing acrylates such as 2- (perfluoro-9-methyldecyl) ethyl acrylate, 3-perfluorodecyl-1,2-epoxypropane, 3- (perfluoro-9-methyldecyl) -1,2-epoxypropane It epoxide, radiation-curable fluorine-containing monomers such as epoxy acrylate, oligomers, and the like prepolymer. These can be used alone or in combination.

Furthermore, it is also possible to use a low reflection material obtained by mixing a sol obtained by dispersing ultrafine silica particles of 5 to 30 nm in water or an organic solvent and a fluorine-based film forming agent. A sol in which 5 to 30 nm ultrafine silica particles are dispersed in water or an organic solvent is a method in which alkali metal ions in an alkali silicate salt are dealkalized by ion exchange or the like, or a method in which an alkali silicate salt is neutralized with a mineral acid A known silica sol obtained by condensing active silicic acid known in the art, a known silica sol obtained by condensing alkoxysilane with hydrolysis in an organic solvent in the presence of a basic catalyst, and the above-mentioned aqueous sol An organic solvent-based silica sol (organosilica sol) obtained by substituting water in the silica sol with an organic solvent by a distillation method or the like is used. These silica sols can be used in both aqueous and organic solvent systems. In producing the organic solvent-based silica sol, it is not necessary to completely replace water with the organic solvent. The silica sol, a solid content of 0.5 to 50% strength by weight as SiO _2. Various structures such as a spherical shape, a needle shape, and a plate shape can be used as the structure of the silica ultrafine particles in the silica sol.

  As the film forming agent, alkoxysilane, metal alkoxide, hydrolyzate of metal salt, or fluorine-modified polysiloxane can be used. Among the film forming agents as described above, it is particularly preferable to use a fluorine compound because the critical surface tension of the low reflection layer is lowered and adhesion of oil can be suppressed. The low reflection layer of the present invention is prepared by diluting the above-mentioned materials with a solvent, for example, spin coater, roll coater, printing, etc. on the radiation curable resin layer, drying, heat, radiation (in the case of ultraviolet rays) Can be obtained by curing using the above-mentioned photopolymerization initiator. Radiation curable fluorine-containing monomers, oligomers and prepolymers are excellent in stain resistance, but have poor wettability, so depending on the composition, there may be a problem of repelling the low reflection layer on the radiation curable resin layer, and low reflection. Since there is a possibility that the layer may be peeled off from the radiation curable resin layer, the acryloyl type, methacryloyl type, acryloyloxy group, methacryloyloxy group, etc. described as the above-mentioned radiation curable resin used for the radiation curable resin layer, etc. It is desirable to mix and use monomers, oligomers and prepolymers having a polymerizable unsaturated bond as appropriate.

  When a plastic film such as PET or TAC that is easily damaged by heat is used for the translucent substrate, it is preferable to select a radiation curable resin as the material of the low reflection layer.

The thickness for the low reflection layer to exhibit a good antireflection function can be calculated by a known calculation formula. In the case where incident light is perpendicularly incident on the low reflection layer, the condition for the low reflection layer not to reflect light and to transmit 100% should satisfy the following relational expression. In the formula, N ₀ represents the refractive index of the low reflective layer, N _s represents the refractive index of the radiation curable resin layer, h represents the thickness of the low reflective layer, and λ ₀ represents the wavelength of light.

  According to the above formula (1), in order to prevent reflection of light by 100%, a material in which the refractive index of the low reflective layer is the square root of the refractive index of the lower layer (radiation curable resin layer) should be selected. I know it ’s good. However, in reality, it is difficult to find a material that completely satisfies this mathematical formula, and a material that is as close as possible is selected. In the above equation (2), the optimum thickness as the antireflection film of the low reflection layer is calculated from the refractive index of the low reflection layer selected in the equation (1) and the wavelength of light. For example, when the refractive indexes of the radiation curable resin layer and the low reflection layer are 1.50 and 1.38, the wavelength of light is 550 nm (visibility standard), and these values are substituted into the above equation (2), The thickness of the low reflection layer is calculated to be optimal when the optical film thickness is around 0.1 μm, preferably in the range of 0.1 ± 0.01 μm.

《Anti-fouling layer》
In the optical laminate according to the best mode, an antifouling layer can be provided above the optical functional layer. The antifouling layer contains at least a perfluoroalkyl ether compound, and the compound functions as an antifouling component that substantially exhibits antifouling properties, and a compound having a perfluoroalkyl ether group is appropriately used. Among them, a compound having at least one functional group having high affinity with a silica film described below and / or one or more functional groups capable of being chemically bonded is preferable. The perfluoroalkyl ether compound used is not limited to one type, and two or more types can be mixed and used. Furthermore, the molecular weight of these compounds is preferably 500 to 10,000, and more preferably 500 to 4000. This is because if the molecular weight is 500 or less, sufficient antifouling property and durability cannot be exhibited, and if it is 10,000 or more, the solubility in a solvent decreases and it becomes difficult to form a uniform antifouling layer.

<Antistatic layer>
In the optical laminate according to the best mode, an antistatic layer can be provided above and below the optical functional layer (between the optical functional layer and the translucent substrate). The antistatic layer is made by depositing a metal oxide film such as aluminum or tin, or a metal oxide film such as ITO very thinly by sputtering, metal fine particles such as aluminum or tin, whisker, antimony or the like on a metal oxide such as tin oxide. Polyesters such as fillers formed from doped fine particles, whiskers, 7,7,8,8-tetracyanoquinodimethane and electron donors (donors) such as metal ions and organic cations It can be provided by a method in which it is dispersed in a resin, an acrylic resin, an epoxy resin or the like and provided by solvent coating, or a method in which polypyrrole, polyaniline or the like is doped with camphorsulfonic acid or the like is provided by solvent coating or the like. In the case of optical use, the transmittance of the antistatic layer is preferably 80% or more.

《Near-infrared cut layer》
In the optical laminate according to the best mode, a near-infrared cut layer can be provided above and below the optical functional layer (between the optical functional layer and the translucent substrate). The near-infrared cut layer can be formed by containing a near-infrared cut dye. The near-infrared cut dye is a dye having a maximum absorption value in the near infrared having a wavelength of 780 nm or more, and is a phthalocyanine dye, an aluminum dye, an anthraquinone dye, a naphthalocyanine dye, a dithiol complex dye, a polymethine dye, Examples include pyrylium dyes, thiopyrylium dyes, squarylium dyes, croconium dyes, azurenium dyes, tetradehydrocholine dyes, triphenylmethane dyes, and diimmonium dyes. These may be used alone or in combination of two or more. Used in combination. Specific examples of near-infrared cut dyes include EX color 802K, EX color 803K, EX color 814K (all of which are trade names manufactured by Nippon Shokubai Co., Ltd.), IR-750, IRG-002, IRG-003, and IRG. -022, IRG-023, IRG-820, CY-2, CY-4, CY-9, CY-20 (all are trade names manufactured by Nippon Kayaku Co., Ltd.), PA-001, PA-1005, PA- 1006, SIR-114, SIR-128, SIR-130, SIR-159 (all are trade names manufactured by Mitsui Toatsu Chemical Co., Ltd.).

《Polarizing layer》
Moreover, you may make the optical laminated body which concerns on this best form into a polarizing film. In this case, the polarizing film is provided with an optical functional layer containing at least transparent fine particles (a layer in which the above-mentioned area dispersion variation is within a predetermined range) directly or via another layer on one surface of the first protective material. The second protective material is laminated on the surface opposite to the surface layer through a polarizing layer. The polarizing layer may be a light-absorbing polarizing film that transmits only specific polarized light and absorbs other light, or a light-reflecting 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 a light reflection type polarizing element, for example, two kinds of polyester resins (PEN and PEN copolymer) having different refractive indexes in the stretching direction when stretched are alternately laminated by several hundred layers and stretched. "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. .

  Furthermore, the optical layered body preferably has a transmitted image definition in the range of 5.0 to 70.0 (a value measured using a 0.5 mm optical comb in accordance with JIS K7105), more preferably 20.0 to 65.0. preferable. When the transmitted image definition is less than 5.0, the contrast is deteriorated, and when it exceeds 70.0, the antiglare property is deteriorated, so that it is not suitable for an optical laminate used for a display surface.

  The optical layered body preferably has an internal haze value (X) and a total haze value (Y) satisfying the following formulas (1) to (4). Here, “total haze value” refers to the haze value of the optical laminate, and “internal haze value” refers to the haze in a state where a transparent sheet with an adhesive is bonded to the fine uneven surface of the optical laminate. The value which subtracted the haze value of the transparent sheet with an adhesive from a value is pointed out. In addition, all haze values point out the value measured according to JISK7105.

Y> X (1)
Y ≦ X + 7 (2)
X ≦ 15 (3)
X ≧ 1 (4)

  Here, in the range of Y> X + 7, X ≦ 15, and X ≧ 1, the surface becomes whitish due to the increased light diffusion effect on the surface, and the contrast is lowered. In particular, the contrast in the bright room is poor. In the range of Y> X, Y ≦ X + 7, and X> 15, the light diffusion effect inside the optical layered body (particularly the optical function layer) is increased, and the contrast is lowered. In particular, the contrast in the dark room decreases. In the range of Y> X, X <1, Y ≦ X + 7, the light diffusion effect inside the optical layered body becomes small, and thus glare appears. Preferred ranges are Y> X, Y ≦ X + 7, 3 <X ≦ 15.

<Properties of optical laminate>
Next, the properties of the optical laminate according to the best mode will be described in detail. The optical layered body according to the best mode has the following scratch resistance. By protecting the surface of the translucent organic filler with metal oxide fine particles, the filler becomes hard and tough, and the adhesion between the filler and the resin increases, so that the resin on the filler (on the surface of the optical functional layer) Convex part) is difficult to cut.

"Production method"
Next, the manufacturing method of the optical laminated body which concerns on this best form is explained in full detail. First, the manufacturing method of the optical functional layer of the optical laminate according to the best mode will be described. The optical functional layer is not particularly limited. For example, a metal oxide sol is added to a premix of a translucent resin composition, a translucent organic filler, a solvent, a leveling agent, and a thickener, and stirred with a disper or the like. The desired paint is obtained by applying the prepared paint on a transparent substrate, drying with a dryer, and irradiating with UV. At this time, it is possible to make the metal oxide fine particles unevenly distributed on the surface of the light transmissive organic filler by providing an affinity between the light transmissive organic filler and the metal oxide fine particles by any of the methods described above. Become. The viscosity of the paint is preferably 10 to 2000 cp for uneven distribution. A drying temperature of 50 to 130 ° C. is suitable for uneven distribution. A drying speed of 10 to 50 m / min is suitable for uneven distribution. Moreover, it is preferable to provide a preliminary drying process immediately after applying the produced coating material on a transparent substrate to form a coating film and before entering a dryer drying process. As a result, the coating film can be dried more slowly, so that the metal oxide fine particles are likely to be unevenly distributed on the surface of the translucent organic filler. The preliminary drying step refers to a step in which a weak air flow is uniformly blown against the coating film from a substantially vertical direction of the coating film plane. The air volume of the weak air current is preferably 0.01 to 1.0 m / sec. The said air volume should just be measured in the state which separated the wind speed detection hole of the anemometer (KANOMAX CLIMO MASTER (trademark)) 1 cm from the coating film. Moreover, what is necessary is just to set the temperature of the airflow in a preliminary drying process to 20-60 degreeC.

  About the other structure of the optical laminated body which concerns on this best form, it can manufacture with the manufacturing method of the conventional optical laminated body. For example, the method for forming the optical functional layer on the translucent substrate is not particularly limited. For example, a paint containing a radiation curable resin composition containing translucent fine particles is applied on the translucent substrate. Then, after drying, a curing treatment is performed to create an optical functional layer having a fine uneven shape on the surface. As a method for applying the paint 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.

<Example 1>
As a dispersion of fine metal oxide particles, 500 parts of “Nanotech alumina / alcohol dispersion” (particle size 31 nm, total solid concentration 15%) manufactured by CI Kasei Co., Ltd. was used as a surface modifier, Shin-Etsu Chemical ( 5 parts of “KBE-903” (= γ-aminoxypropyltriethoxysilane) manufactured by the same company was added, and the mixture was stirred and mixed at room temperature for 10 minutes with a homogenizer. Thereafter, while continuing stirring, 0.2 part of triethylamine was diluted 10-fold with methanol and then dropped, and stirring was continued at 60 ° C. for 12 hours to sufficiently react the surface modifier. Next, this dispersion was transferred to an ultrafiltration device (“MQLSEP” FSIO-FUS1582 manufactured by Daisen Membrane Systems: membrane area 5 m ² , manufactured by polyethersulfone, molecular weight cut off 150,000, length 1129 mm × diameter 89 mm). Then, the unreacted surface modifier was washed. The solution was pumped to a filtration pressure of 1.6 kg / m ^2, and pure isopropanol was fed to the outside of the membrane. Filtration was continued while returning the sol that passed without being filtered, and when the amount of the sol reached about 60 to 70% of the initial amount, pure isopropanol was added to maintain the concentration. Next, 200 parts of the dispersion liquid (15%) prepared above and 70 parts of TPGDA (tripropylene glycol diacrylate) were stirred with a stirring blade and a three-one motor (BL300R manufactured by Heidon Co., Ltd.), and the alcohol component was distilled. To obtain a sol (liquid A) of the metal oxide fine particles of the present invention. Here, 30% by weight of the solid content of the liquid A is metal oxide fine particles.
Next, a coating for the optical functional layer obtained by stirring the predetermined mixture described in Table 1 containing the liquid A with a disper for 30 minutes is used as a transparent substrate having a film thickness of 80 μm and a total light transmittance of 92%. TAC (Fuji Film; TD80UL) on one side by roll coating method (line speed; 20 m / min), pre-dried at 30 to 50 ° C. for 20 seconds, and then 100 ° C. For 1 minute, and then UV irradiation (lamp; condensing high-pressure mercury lamp, lamp output: 120 W / m, number of lamps: 4 lamps, irradiation distance: 20 cm) in a nitrogen atmosphere (replacement with nitrogen gas) The film was cured. Thus, the optical laminated body of Example 1 which has an optical function layer with a thickness of 6.0 micrometers was obtained.
<Example 2>
The optical layered body of Example 2 is obtained in the same manner as in Example 1 except that the coating material for the optical function layer is changed to the predetermined mixed solution shown in Table 1 and the film thickness of the optical function layer is 9.0 μm. It was.
<Example 3>
Metal oxide fine particles were dispersed in the same manner as in Example 1 using “Zinc oxide fine particles NANOBYK3841” (particle size 40 nm, 40% dispersion; diluted with methoxypropyl acetate) manufactured by Big Chemie Japan Co., Ltd. A fine particle sol (liquid B) was obtained. Here, 40% by weight of the solid content of the B liquid is metal oxide fine particles. Next, a coating for an optical functional layer obtained by stirring the predetermined mixture shown in Table 1 containing the liquid B with a disper for 30 minutes is used as a transparent substrate having a film thickness of 40 μm and a total light transmittance of 92%. TAC (manufactured by Konica Minolta Opto; KC4UYW) was applied by a microgravure coating method (line speed; 20 m / min), and pre-dried at 30 to 50 ° C. for 20 seconds. Thereafter, drying is performed at 80 ° C. for 1 minute, and ultraviolet irradiation (lamp; condensing high-pressure mercury lamp, lamp output: 100 W / cm, number of lamps: 4 lamps, irradiation distance: 20 cm) is performed in a nitrogen atmosphere (replacement with nitrogen gas). Thus, the coating film was cured. Thus, the optical laminated body of Example 3 which has an optical function layer with a thickness of 8.0 micrometers was obtained.
<Comparative Example 1>
A comparative example 1 optical laminate was obtained in the same manner as in Example 1 except that the optical functional layer coating material was changed to the predetermined mixed solution shown in Table 1 and the film thickness of the optical functional layer was changed to 5.0 μm. .
<Comparative example 2>
A comparative example 2 optical laminate was obtained in the same manner as in Example 1 except that the optical functional layer coating material was changed to the predetermined mixed solution shown in Table 1 and the thickness of the optical functional layer was changed to 7.0 μm. .
<Comparative Example 3>
A comparative example 3 optical laminate was obtained in the same manner as in Example 1 except that the coating material for the optical functional layer was changed to the predetermined mixed solution shown in Table 1 and the film thickness of the optical functional layer was changed to 4.0 μm. .
<Comparative example 4>
A comparative example 4 optical laminate was obtained in the same manner as in Example 1 except that the metal oxide fine particles were alumina sol (liquid C) having a particle size of 120 nm. Here, 30% by weight of the solid content of the liquid C is fine metal oxide particles.

Adhesion was performed according to the cross-cut method of JIS K5600.
The cut interval is 1 mm and the number of cuts is 11. In the evaluation, the ratio of the number of cross-cut lattices that have not been peeled is displayed in%. For example, if 5 pieces are peeled, 95/100 is displayed.
The total light transmittance was measured according to JIS K7105 using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku Co., Ltd.).
The haze value was measured according to JIS K7105 using a haze meter (trade name: NDH2000, manufactured by Nippon Denshoku Co., Ltd.).
The “inside haze value” is a value obtained by subtracting the haze value of the transparent sheet with adhesive from the haze value of the state in which the transparent sheet with pressure-sensitive adhesive is bonded to the fine uneven surface of the optical laminated film. is there.
The transparent sheet with pressure-sensitive adhesive used when measuring the noise into the interior is as follows.
Transparency sheet: Component Polyethylene terephthalate (PET) thickness 38μm
Adhesive layer: Component Acrylic adhesive, 10μm thick
Haze of transparent sheet with adhesive 3.42
The “external haze value” was calculated by the following formula using “haze value” and “internal haze value”. “External Haze Value” = “Haze Value” − “Internal Haze Value”
Transmission image clarity
According to JIS K7105, a measuring device (trade name: ICM-IDP, manufactured by Suga Test Instruments Co., Ltd.) was used, and the measuring device was set to a transmission mode and measured at an optical comb width of 0.5 mm.
Scratch resistance Steel wool # 0000 manufactured by Nippon Steel Wool Co., Ltd. was attached to an abrasion tester (Abrasion Tester, Model: 339 manufactured by Fu Chien Co., Ltd.), and the optical functional layer surface was reciprocated 10 times at a load of 250 g / cm ² . . Thereafter, scratches on the worn part were confirmed under a fluorescent lamp. ◎ when the number of scratches was 0, 0 when the number of scratches was less than 1-10, Δ when the number of scratches was less than 10-30, and x when the number of scratches was 30 or more.
Surface hardness (pencil hardness)
It measured based on JIS5400 using the pencil hardness meter (made by Yoshimitsu Seiki Co., Ltd.). The number of measurements was set to 5 times, and the number without scratches was counted. For example, with 3H pencil, if there are no 3 scratches, 3/5 (3H). The pencil hardness was 4/5 (3H) or higher.
Anti- glare properties Anti-glare properties were evaluated as ◎ when the value of transmitted image definition was 0-30, ◯ when 31-70, and x when 71-100.
Contrast (C / R)
The contrast is 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-forming surface of each example and each comparative example via a colorless and transparent adhesive layer. When the illuminance on the surface of the liquid crystal display is set to 200 lux with a fluorescent lamp (product name: HH4125GL, manufactured by National Corporation) from the direction 60 ° above the front of the display screen, and then the liquid crystal display is displayed in white and black. color luminance meter the brightness of the (trade name: BM-5A, manufactured by Topcon Corporation) was measured by the resulting black display at the time of the luminance (cd / ^{m 2)} and white display at the time of the luminance (cd / ^{m 2)} When the value calculated by the following formula is 600 to 800, x, when 801 to 1000, ◯, when 1001 to 1200, ◎. Contrast = Brightness of white display / Brightness of black display
Glare glare is a surface opposite to the optical laminate forming surface of each of Examples and Comparative Examples, colorless and transparent resolution via the adhesive layer 50ppi liquid crystal display (trade name: LC-32GD4, manufactured by Sharp Corporation) and, Liquid crystal display with a resolution of 100 ppi (trade name: LL-T1620-B, manufactured by Sharp), liquid crystal display with a resolution of 120 ppi (trade name: LC-37GX1W, manufactured by Sharp), and liquid crystal display with a resolution of 140 ppi (product) Name: VGN-TX72, manufactured by Sony Corporation, liquid crystal display with a resolution of 150 ppi (trade name: nw8240-PM780, manufactured by Hewlett-Packard Japan), and liquid crystal display with a resolution of 200 ppi (trade name: PC-CV50FW, Sharp Corporation) ) And the liquid in a dark room. After displaying the display in green, the resolution value when the brightness variation is not confirmed in an image taken by 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 with ○ when it was 51 to 140 ppi, and ◎ when it was 141 to 200 ppi.
A section of the optical functional layer constituting the unevenly distributed optical laminate was prepared, and the cross section was observed with a TEM. The number of the metal oxide fine particles observed around the cross section of the translucent organic filler per 1 μm perimeter of the cross section of the translucent organic filler ([the number of metal oxide fine particles observed around the translucent organic filler cross section (surface) Number] / [section length of translucent organic filler])). A TEM photograph of a cross section of the optical functional layer according to Example 1 is shown in FIG. A TEM photograph according to Comparative Example 1 is shown in FIG.

  Table 2 summarizes the evaluation results.

1 is a TEM photograph of a cross section of an optical functional layer according to Example 1. FIG. FIG. 2 is a TEM photograph of a cross section of the optical functional layer according to Comparative Example 1.

Claims (4)

An optical laminate in which at least an optical functional layer is provided on one side or both sides of a translucent substrate directly or via another layer,
The optical functional layer is
A translucent resin as a matrix;
A translucent organic filler dispersed in the translucent resin;
Metal oxide fine particles having a particle size of 1 to 100 nm and a blending amount of 0.1 to 10% by weight,
Here, the metal oxide fine particles are unevenly distributed on the surface of the translucent organic filler.   The optical laminate according to claim 1, wherein the metal oxide fine particles are alumina fine particles. An application step of applying a coating formed by mixing at least an energy curable resin composition, a translucent organic filler, and a metal oxide sol directly or via another layer to one or both sides of a translucent substrate; ,
The manufacturing method of an optical laminated body including the hardening process which applies an energy after the said application process, hardens the said energy curable resin composition, and forms an optical function layer.   The manufacturing method of the optical laminated body of Claim 3 whose said metal oxide sol is an alumina sol.

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