JP2010223985A - Metal oxide fine particle, coating material, optical laminate, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide metal oxide fine particles which provide good visibility on a screen while having excellent physical strength (pencil hardness and wear resistance) and chemical resistance and is suitably available for displays such as an LCD and a PDP, a coating material using the metal oxide fine particles, an optical laminate using the coating material, and a manufacturing method thereof. <P>SOLUTION: The metal oxide fine particles are mixed with an organic polymer compound after being subjected to surface treatment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a metal oxide fine particle, a paint, and an optical laminate provided on a display surface such as a liquid crystal display (LCD) or a plasma display (PDP), and a method for producing the same, and particularly relates to physical strength, chemical resistance, and screen visibility. It is related with the optical laminated body for improving.

One of the various image display devices is the LCD. With technological innovations related to LCDs with a wide viewing angle, high definition, high-speed response, and color reproducibility, applications that use LCDs are also small and medium-sized laptops. It has expanded from monitors to large televisions. The basic structure of an LCD is that a gap with a constant interval is provided between a flat glass plate having two transparent electrodes by a spacer, and a liquid crystal material is injected and sealed there to seal the flat glass plate. Polarizing plates are attached to the front and back surfaces. Since the polarizing plate located on the outermost surface of the display is easily damaged, for example, a cover plate made of glass or plastic is attached to the LCD surface to prevent the polarizing plate attached to the LCD surface from being damaged. It was. However, the cover plate is disadvantageous in terms of cost and weight, and a polarizing plate that has been subjected to a hard coat treatment that overcomes the above-described problem (preventing damage to the polarizing plate) has come to be used.

The hard coat layer is usually formed as a thin coating film of about several μm on a transparent plastic film substrate using an ionizing radiation curable resin such as a thermosetting resin or an ultraviolet curable resin. However, if the thickness of the hard coat layer is not sufficient, the surface of the hard coat layer is damaged by a physical impact on the surface portion due to the influence of the transparent plastic film substrate as a base. In LCD applications, triacetyl cellulose (TAC) film is mainly used as a transparent plastic film substrate, but pencil hardness (JIS K5600), which is a representative measurement method for evaluating the physical strength of the hard coat layer surface, The load resistance in the steel wool abrasion resistance test (details will be described later) was generally ^{2 to 3} H and 250 g / cm ² or less, respectively.

LCDs and PDPs are very popular in the TV market, but these displays are also handled by consumers in the same way as conventional CRT TVs (load due to physical, mechanical, chemical stimulation, etc.) There is a need for a design that takes into account. Examples of strict handling by general consumers include dirt and fingerprints adhering to the display surface, wiped with a cloth soaked with glass cleaner (various surfactants, organic solvents, etc.), or children toys It is assumed that the surface is rubbed. The cathode ray tube of CRT was made of glass with excellent chemical resistance, and the surface hardness was about 9H in pencil hardness, so that the durability against these loads was sufficient. However, the surface of the conventional hard coat layer of the optical layered body mounted on the display has insufficient pencil hardness and wear resistance, and also has a problem in chemical resistance, and improvement is demanded.

Further, it has been pointed out that the reflection of light at the interface between the transparent plastic film substrate and the air layer sandwiching the hard coat layer causes a decrease in contrast and interference unevenness (details will be described later), resulting in a decrease in visibility.

As a method for improving the physical strength of the surface of the hard coat layer, a method for increasing the thickness of the same layer is conceivable. However, although the hardness is increased by the above method, the production of the optical laminate or the optical laminate may be caused by wrinkles or curls of the optical laminate caused by the curing shrinkage of the hard coat layer, or the hard coat layer may be bent, cracked or peeled off. There was a problem that production of applied downstream products would be hindered. Thus, in recent years, several methods have been proposed for solving these problems while realizing high hardness of the optical laminate.

For example, an optical laminate comprising a functional layer (hard coat layer) obtained by curing a resin composition containing an acrylic polymer having a polymerizable double bond in the side chain and fine particles on a substrate is disclosed. (For example, refer to Patent Document 1). It is disclosed that the wear resistance and hardness of the hard coat layer are improved by adding fine oxide particles to the resin composition. Then, modification is performed to bond an organic compound containing a polymerizable unsaturated group to the surface of the oxide fine particle, and a polymerizable double bond is introduced to the surface of the fine particle, thereby forming a crosslinked structure with the polymerizable acrylic polymer. It is described that the hardness of the coating film (hard coat layer) is improved.

JP 2007-293272 A

However, the surface hardness of the hard coat layer is not sufficient only by curing a resin composition containing fine particles having a polymerizable double bond and a polymerizable acrylic polymer to form a hard coat layer. It was. That is, as in Patent Document 1, it is difficult to form a sufficient cross-linked structure between the fine particles and the polymerizable acrylic polymer simply by introducing a polymerizable double bond on the surface of the fine particles. It was.
Further, the optical laminate of Patent Document 1 has a problem in that the visibility of the optical laminate is deteriorated because the dispersion of the fine particles in the formed hard coat layer is insufficient and the fine particles tend to aggregate and exist. was there.

The present invention has excellent physical strength (pencil hardness and abrasion resistance) and chemical resistance, has good screen visibility, and can be suitably used for LCD and PDP display applications. It is an object to provide a metal oxide fine particle that can be produced, a paint using the metal oxide fine particle, an optical laminate using the paint, and a method for producing the same.

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

(1) Metal oxide fine particles obtained by surface-treating metal oxide fine particles and then mixing with organic polymer compounds.
(2) A paint containing at least a surface-treated and organic polymer compound and mixed metal oxide fine particles, an energy curable resin, and an organic solvent.
(3) The coating material according to (2), wherein the organic polymer compound has a molecular weight of 10,000 to 200,000.
(4) After the coating material according to (2) or (3) is applied on the translucent substrate, a hard coat layer obtained by curing the coating material with energy is laminated, An optical laminate in which the metal oxide fine particles are dispersed substantially uniformly.
(5) Production of metal oxide fine particles, comprising: a step of surface-treating metal oxide fine particles; and a step of mixing the metal oxide fine particles surface-treated in the above step with an organic polymer compound. Method.

According to the present invention, it has excellent physical strength (pencil hardness and abrasion resistance) and chemical resistance, has good screen visibility, and is suitably used for LCD and PDP display applications. It is possible to provide a metal oxide fine particle that can be used, a paint using the metal oxide fine particle, an optical laminate using the paint, and a method for producing the same.

In addition, the optical laminate obtained by the present invention is formed of a paint comprising a metal oxide fine particle, an energy curable resin, and an organic solvent in which a hard coat layer is subjected to a surface treatment and an organic polymer compound. As a result, the physical strength and chemical resistance were excellent, and the visibility was also better than before due to the good dispersion of the metal oxide fine particles in the hard coat layer.

It is sectional drawing of the optical laminated body of this invention.

The present invention will be described with reference to the drawings.
As shown in FIG. 1, the optical laminate 1 of the present invention has a basic configuration in which a hard coat layer 20 is laminated on a translucent substrate 10. In the hard coat layer 20, the metal oxide fine particles 40 that have undergone a surface treatment step and a mixing treatment step with an organic polymer compound are contained in a translucent resin (a material obtained by curing an energy curable resin with energy) as a matrix. It consists of a substantially uniformly dispersed structure.
Here, “substantially uniformly dispersed” includes not only a uniformly dispersed state but also a state recognized as being substantially the same as a uniformly dispersed state.

The hard coat layer 20 according to the present invention is preferably located on the outermost surface of the optical laminate 1. Here, the hard coat layer 20 may be laminated on one side of the translucent substrate 10 or may be laminated on both sides. Furthermore, the optical layered body 1 may have other layers. Examples of the other layers include a polarizing layer, a light diffusion layer, a low reflection layer, an antifouling layer, an antistatic layer, an ultraviolet / near infrared (NIR) absorption layer, a neon cut layer, and an electromagnetic wave shielding layer. Can do. The positions of the respective layers are, for example, on the hard coat layer 20 in the case of an antifouling layer and a low reflection layer, the polarizing layer is on the translucent substrate 10 on the surface opposite to the hard coat layer 20, and others. In the case of the functional provision layer, the lower layer of the hard coat layer 20 is used.
Hereinafter, the material constituting the optical laminate according to this embodiment will be mainly described.

<Metal oxide fine particles>
The metal oxide fine particles essential in the hard coat layer will be described in detail.
Specific examples of the metal oxide fine particles include alumina fine particles, zirconia fine particles, titania fine particles, aluminum hydroxide fine particles, tin oxide fine particles, zinc oxide, and cesium oxide. In particular, alumina fine particles are preferable from the viewpoint of the physical strength. In addition, these metal oxide fine particles may be added 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. These may be used alone or in combination.

The metal oxide fine particles constituting the present invention are obtained through at least a surface treatment step and a mixing treatment step. That is, after metal oxide fine particles are surface-treated with a surface modifier (surface treatment step), and then mixed with an organic polymer compound (mixing treatment step), the metal oxide fine particles form a hard coat layer. At this time, it is possible to improve the affinity with the translucent resin having a cross-linking reactive group that is uniformly dispersed in the hard coat layer. Thereby, the hard coat layer forms a high-density cross-linked structure, and exhibits good physical strength and chemical resistance. In addition, since the metal oxide fine particles are dispersed substantially uniformly in the hard coat layer, the visibility of the optical laminate can be improved.

The surface treatment method is not particularly limited, but the metal oxide fine particles may be dispersed in a predetermined solvent, specifically an organic solvent, and a surface modifier may be added to cause a polycondensation reaction. desirable. At this time, the solution subjected to the surface treatment can be appropriately heated to a temperature not higher than the boiling point of the solvent, and in dispersion mixing, techniques such as ultrasonic, microbead mill, stirring, and high-pressure emulsification are used. 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 using an organic solvent. After the surface treatment is completed, the surface modifier that does not contribute to the surface treatment of the metal oxide fine particles is removed and purified by conventional techniques such as drying, solid-liquid separation, and ultrafiltration.

Although the said surface modifier is not specifically limited, The organometallic compounds, such as the conventional silane coupling agent, a silylating agent, alkyllithium, and alkylaluminum, can be mentioned. Of these, silane coupling agents and silylating agents are preferred from the viewpoint of ease of use and cost. Here, the compounding amount of the surface modifier is preferably 0.1 to 10.0% by mass of the metal oxide fine particles or the metal oxide fine particles constituting the metal oxide sol. If it is less than 0.1% by mass, the dispersibility of the metal oxide fine particles and the affinity with the translucent resin tend to be lowered. If the amount is more than 10.0% by mass, the coating tends to aggregate when it is converted into a coating, which may hinder the stability of the coating.

The silane coupling agent has a structure in which an organic substituent having affinity or reactivity with an organic substance is chemically bonded to a hydrolyzable silyl group having affinity or reactivity with an inorganic material. It is a 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.

Here, the metal oxide fine particles contained in the hard coat layer have a remarkably small particle size and little optical influence, and therefore may basically have any refractive index.

The particle diameter of the metal oxide fine particles is preferably 1 to 100 nm, and more preferably 5 to 50 nm. When the particle size is less than 1 nm, the production cost of the metal oxide fine particles and the metal oxide sol is increased, which is not preferable.
On the other hand, when the particle diameter is more than 100 nm, haze is increased, and the optical properties of the optical laminate such as transmittance and contrast are impaired. The “particle size” can be measured by an image analysis method of a transmission electron microscope, a dynamic light scattering method, a centrifugal sedimentation method, or the like. Here, the diameter of 100 particles measured by an image analysis method of a transmission electron microscope is measured. Refers to the average value. 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 content of the metal oxide fine particles needs to be 0.1 to 10% by mass of the solid component in the hard coat layer, more preferably 0.3 to 5.0% by mass, and 0.5 to 3. 0% by mass is more preferred. When the content is smaller than the above range, scratch resistance is deteriorated. When the content is larger than the above range, the optical properties are hindered.

Next, the mixing treatment of the metal oxide fine particles and the organic polymer compound after the surface treatment will be described. The mixing treatment is an indispensable process for preventing aggregation of metal oxide fine particles, improving affinity with a translucent resin having a crosslinking reactive group, and realizing a high-density crosslinked structure of the hard coat layer. . In addition, it is estimated that the reason why the metal oxide fine particles can be prevented from aggregating is due to the cushioning effect of the organic polymer compound that is bonded to the metal oxide fine particles with a weak intermolecular force.

The mixing treatment method of the present invention is not particularly limited as long as it can bind the polymer compound to the surface of the surface-treated metal oxide fine particles with a weak intermolecular force. For example, it can be carried out by kneading or stirring a mixed solution obtained by diluting the surface-treated metal oxide fine particles and the organic polymer compound with an appropriate solvent. Kneading is a batch type ribbon mixer, double kneader, pressure kneader, internal mixer, power mix, continuous pug mill, KRC kneader, extruder, ultimate kneader, SC processor, etc. The agitator can be selected as appropriate. In order to increase the efficiency of the mixing treatment, it is desirable to perform a process in the order of kneading, solvent dilution, and stirring in a state where the total solid content concentration of the mixed solution is increased in advance with a solvent concentrator or the like. The total solid content concentration before kneading is 50 to 99%, preferably 60 to 90%, and the solid content concentration before stirring is 10 to 50%, preferably 30 to 50%. The kneading / stirring time is adjusted appropriately by confirming that the particle size of the metal oxide fine particles is within the desired particle size range while measuring and monitoring the particle size of the metal oxide fine particles with a measuring device such as a dynamic light scattering method or a centrifugal sedimentation method. To do.
In addition, it is preferable to use what was illustrated with the organic solvent mentioned later as a solvent which dilutes said liquid mixture.

The organic polymer compound used for the mixing treatment is not particularly limited, but a high molecular weight thermoplastic resin is applicable. For example, acrylic resins such as polymethyl methacrylate, polyhydroxy methacrylate, polymethyl methacrylate, ethylene ethyl acrylate copolymer, aliphatic polyester, polydimethylene malonate, polyethylene terephthalate, polytrimethylene terephthalate, polydiethylene glycol terephthalate, Polyethylene isophthalate, polyethylene phthalate, polyethylene-1,5-naphthalate, polyethylene-1,4-naphthalate, polyethylene-2,7-naphthalate, polyester (diethylene glycol-diphenylcarboxylic acid), polyester (bis-P-carboxyphenoxybutane-) Such as polyester resins such as ethylene glycol), polyethylene, polypropylene, polybutylene, polybutadiene, etc. Refin resin, polystyrene, AS resin, BS resin, styrene resin such as ABS resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, ethylene / vinyl acetate copolymer, polyvinyl butyral, vinylidene chloride / acrylonitrile copolymer Polymers, vinyl chloride / vinyl acetate copolymers, vinyl chloride / vinylidene chloride copolymers, vinyl resins such as propylene / vinyl chloride copolymers, polyamide resins such as nylon 6, nylon 66, nylon 12, etc., polycarbonate resins, polyacetals Resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfonic acid, polyurethane resin, tetrafluoroethylene resin, trifluoroethylene resin, polyvinylidene fluoride, etc., ethyl cellulose, cellulose acetate, nitrile Cellulose-based resin such as cellulose, epoxy resin, ionomer resin, rosin derivative resin, organic solvent soluble resin, gelatin, glue, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, carboxymethylhydroxyethylcellulose, hydroxyethyl starch, gum arabic, sucrose Water-soluble resin systems such as octaacetate, ammonium alginate, sodium alginate, polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, polyvinyl amine, polyethylene oxide, polystyrene sulfonic acid, polyacrylic acid, polyamide, isobutylene / maleic anhydride copolymer and the like The organic solvent-soluble resin-based emulsion system described above can be used. These can be used alone or in combination.

The molecular weight of the organic polymer compound is desirably 10,000 to 200,000. More preferably, it is 20,000-150,000, More preferably, it is 50,000-100,000. When the molecular weight exceeds the range of the present invention, the efficiency of the mixing treatment with the metal oxide fine particles is deteriorated, and the affinity with the translucent resin is deteriorated. Furthermore, the crosslink density of the hard coat layer is lowered, and the physical strength and chemical resistance of the hard coat layer are lowered. Here, “molecular weight” refers to the weight average molecular weight (Mw).

<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. It is possible to improve the adhesion between the optical substrate and the hard coat layer and improve the physical strength and chemical resistance of the hard coat layer. Also, when another layer is provided between the translucent substrate and the hard coat layer, the same method as described above improves the adhesion at the interface of each layer, and the physical strength and chemical resistance of the hard coat layer are improved. Can be improved.

<Energy curable resin>
The energy curable resin is not limited as long as it is cured by energy such as heat or radiation. In the present invention, an energy curable resin cured by energy is referred to as a translucent resin. Of the energy curable resins, it is preferable to use a radiation curable resin composition that is cured by radiation. By using a radiation curable resin composition as the translucent resin, a crosslinked structure is formed, so that the wear resistance of the hard coat layer can be improved. 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 this embodiment, 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.

<Organic solvent>
Further, as the organic solvent used in the present invention, it is desirable to use an organic solvent in which the dispersion of the metal oxide fine particles and the dissolution of the surface modifier are good. When an organic solvent with low dispersibility is used, the metal oxide fine particles are aggregated, and when an organic solvent with low solubility is used, the modifier is separated. As the organic solvent, for example, a single solvent or a mixed solvent selected from alcohols, esters, ketones, ethers, and aromatic hydrocarbons can be used.

<Translucent organic fine particles>
When the hard coat layer is used as an antiglare layer, it is preferable to contain translucent organic fine particles in the hard coat layer.
For example, acrylic resin, polystyrene resin, styrene-acrylic copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, polyfluorinated ethylene-based resin, etc. are used as the material constituting the translucent organic fine particles. Can do.

Here, the translucent organic fine particles preferably have a difference in refractive index with the translucent resin of 0.05 or less, more preferably 0.03 or less, and 0.01 The following is more preferable. When the difference in refractive index between the translucent resin and the translucent organic fine particles 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 fine particles 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.

The particle size of the translucent organic fine particles 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. Further, the particle diameter of the light-transmitting organic fine particles 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%). The ratio of the light-transmitting fine particles in the hard coat layer is not particularly limited, but is preferably 1 to 50% by mass of the solid component in the hard coat layer, and more preferably 5 to 10% by mass. is there. When it is within this range, it is preferable for satisfying properties 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 hard coat layer.

By increasing the affinity between the light-transmitting organic fine particles and the metal oxide fine particles, high physical strength can be imparted with a small amount. As a method for increasing the affinity, there is a method using translucent organic fine particles copolymerized with a monomer having a functional group such as a carboxylic acid group or an OH group.
In addition, there is a method of adding an intermediate agent having affinity to both the light-transmitting organic fine particles 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, 0.1-10 mass% of the solid component in a hard-coat layer is suitable for content of an intermediate agent, and 0.2-0.5 mass% is more suitable.

<Structure of paint and hard coat layer of the present invention>
The coating material of the present invention is obtained by mixing the metal oxide fine particles that have undergone the surface treatment step and the mixing treatment step with the organic polymer compound with a translucent resin and an organic solvent. Although there is no restriction | limiting in particular about the method of mixing, It is desirable to mix using the stirring apparatus in a mixing process process. The film thickness of the hard coat 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 hard coat 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.

<Optical laminate>
The optical layered body of the present invention preferably has a transmitted image definition in the range of 5.0 to 70.0 (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 hard coat 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.

About the other structure of the optical laminated body which concerns on this form, it can be manufactured with the manufacturing method of the conventional optical laminated body. For example, there is no particular limitation on the method for forming the hard coat layer on the translucent substrate. For example, the paint of the present invention containing the translucent fine particles is coated on the translucent substrate and dried. Then, it hardens and performs by creating the hard-coat layer which has a fine uneven | corrugated 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.

EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not restrict | limited to these. “Part” means “part by mass”.

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 Cai Kasei Co., Ltd. is used as a surface modifier. 5 parts of “KBE-903” (= γ-aminoxypropyltriethoxysilane) 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 is put into an ultrafiltration device (“MQLSEP” FSIO-FUS1582 manufactured by Daisen Membrane Systems Co., Ltd .: membrane area 5 m ² , manufactured by polyethersulfone, molecular weight cut off 150,000, length 1129 mm × diameter 89 mm). 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 is continued while returning the sol that has passed without being filtered, and when the sol reaches about 60 to 70% of the initial amount, pure isopropanol is added to maintain the concentration, and the surface treatment according to the present invention is completed. It was. Next, 180 parts of the dispersion (solid content concentration: 15%) prepared as described above and an organic polymer compound “Therolac LP45-M30” (Mw: 88,000 polymethyl methacrylate, MEK / toluene) manufactured by Soken Chemical Co., Ltd. 30 parts solution) was stirred with a stirring blade and a three-one motor (BL300R manufactured by Heidon) while maintaining the concentration, and the mixing treatment according to the present invention was performed. Thereafter, the solvent was distilled off to obtain a sol of metal oxide fine particles (liquid A: solid content concentration 30%). 90% by mass of the solid content of the liquid A is metal oxide fine particles.
Next, the coating material of the present invention for a hard coat layer obtained by stirring the predetermined mixture described in Table 1 containing the liquid A with a disper for 30 minutes was obtained from a film thickness of 80 μm and a total light transmittance of 92%. A transparent substrate TAC (“TD80UL” manufactured by Fuji Film Co., Ltd.) is coated on one side by a roll coating method (line speed: 20 m / min), and pre-dried at 30 to 50 ° C. for 20 seconds. After that, it was dried at 100 ° C. for 1 minute and irradiated with ultraviolet rays in a nitrogen atmosphere (replaced with nitrogen gas) (lamp; condensing high-pressure mercury lamp, lamp output: 120 W / m, number of lamps: 4 lamps, irradiation distance: 20 cm) The coating film was hardened by performing. Thus, the optical laminated body of Example 1 which has a 10.0-micrometer-thick hard-coat layer was obtained.

  The hard coat layer paint is a predetermined mixed solution shown in Table 1, the organic polymer compound in the mixing treatment step is thermo-lac “EF30” (polyol) manufactured by Soken Chemical Co., and the hard coat layer has a film thickness of 9. An optical laminate of Example 2 was obtained in the same manner as Example 1 except that the thickness was 0 μm.

  By using “Zinc oxide fine particles NANOBYK3841” (particle size: 40 nm, 40% dispersion; diluted with methoxypropyl acetate) manufactured by Big Chemie Japan for the dispersion of metal oxide fine particles, metal oxide fine particles were obtained in the same manner as in Example 1. Sol (liquid B) was obtained (liquid B: solid content concentration 40%). Next, the coating composition according to the present invention for a hard coat layer obtained by stirring the predetermined mixture described in Table 1 containing the liquid B with a disper for 30 minutes, has a film thickness of 80 μm and a total light transmittance of 92%. A transparent substrate TAC (manufactured by Konica Minolta Opto; KC4UYW) is coated on one side by a microgravure coating method (line speed: 20 m / min), and the air volume is 0.5 m / sec, at 30 to 50 ° C. for 20 seconds. After pre-drying, it was dried at 80 ° C. for 1 minute and irradiated with ultraviolet rays in a nitrogen atmosphere (replacement with nitrogen gas) (lamp; condensing high-pressure mercury lamp, lamp output; 100 W / cm, number of lamps: 4 lamps, irradiation distance; 20 cm), the coating film was cured. Thus, the optical laminated body of Example 3 which has a hard-coat layer with a thickness of 5.0 micrometers was obtained.

The optical layered body of Example 4 is obtained in the same manner as in Example 1 except that the hard coat layer coating material is changed to the predetermined mixed solution shown in Table 1 and the film thickness of the hard coat layer is 7.0 μm. It was.

[Comparative Example 1]
Comparative Example as in Example 1 except that the hard coat layer coating material was changed to a mixed solution containing no predetermined metal oxide fine particles described in Table 1 and the hard coat layer thickness was 5.0 μm. 1 was obtained.

[Comparative Example 2]
A comparative example was made in the same manner as in Example 1 except that the hard coat layer coating material was changed to a mixed solution containing no predetermined metal oxide fine particles described in Table 1 and the hard coat layer thickness was 2.0 μm. 2 optical laminates were obtained.

[Comparative Example 3]
As a dispersion of the metal oxide fine particles, the same as in Example 1 except that the surface treatment of the liquid A was performed but the mixing treatment was not performed (liquid A ′). An optical laminate was obtained.

[Comparative Example 4]
Comparative Example as in Example 1 except that the dispersion of the metal oxide fine particles used was only the mixing treatment A but not the surface treatment (A ″ solution). 4 was obtained.
The materials used in the examples and comparative examples are summarized in Table 1.

The Examples and Comparative Examples of the optical layered body of the present invention were evaluated by the following methods.

Adhesion The adhesion between the hard coat layer and the translucent substrate was carried out 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.).

Abrasion resistance Steel wool # 0000 manufactured by Nippon Steel Wool Co., Ltd. was attached to an abrasion resistance tester (Abrasion Tester, Model: 339 manufactured by Fu Chien Co., Ltd.), and the hard coat layer surface was applied 10 times at a load of 250 g / cm ² . I made a round trip. Thereafter, scratches on the worn part were confirmed under a fluorescent lamp. ◎ when the number of scratches is 0, ◯ when the number of scratches is less than 1-10, △ when the number of scratches is less than 10-30, and × when the number of scratches is 30 or more It was.

Surface hardness (pencil hardness)
The surface hardness of the hard coat layer surface was measured based on JIS 5400 using a pencil hardness meter (manufactured 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.

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. The brightness of the black display (cd / m ² ) and the brightness of the white display (cd / m ² ) were measured with a color luminance meter (trade name: BM-5A, manufactured by Topcon). When the value calculated by the following formula was 600 to 800, it was rated as x, when it was from 801 to 1000, and when it was from 1001 to 1200.
Contrast = Brightness of white display / Brightness of black display

Chemical resistance On the hard coat layer surface, ammonia 2 [%] solution, methanol, toluene, ligroin, light oil, artificial sweat, unleaded gasoline, salt water 10 [%], sulfuric acid 10 [%], acetic acid 10 [%] , IPA, ethanol, neutral detergent, carbonated beverage (cola), wet napkin, hand cream, hair liquid, and then left for 2 hours before wiping with a cloth (Kuraray Clean Wiper “Sorib”), hard Appearance changes such as cracks, blisters, and color changes were visually observed on the coating layer surface. As a result, the case where no change in the appearance was observed with all the chemicals was marked as ◯, and the case where even a change in the appearance was recognized was marked as x.

Table 2 summarizes the evaluation results. Table 2 shows the case where the metal oxide fine particles were surface-treated as ◯, the case where the metal oxide fine particles were not treated as x, the case where the mixing treatment was performed as ◯, and the case where the metal oxide fine particles were not treated as x.

As described above, according to the present invention, while having excellent physical strength (pencil hardness and abrasion resistance) and chemical resistance, the screen visibility is good, and it can be used for LCD and PDP display applications. The paint which can be used conveniently and the optical laminated body using the paint can be provided.

DESCRIPTION OF SYMBOLS 1 Optical laminated body 10 Translucent base | substrate 20 Hard-coat layer 30 Translucent resin 40 Metal oxide fine particle

Claims (5)

Metal oxide fine particles obtained by surface-treating metal oxide fine particles and then mixing with organic polymer compounds. A paint comprising at least a surface-treated and organic oxide compound mixed with metal oxide fine particles, an energy curable resin, and an organic solvent. The paint according to claim 2, wherein the molecular weight of the organic polymer compound is 10,000 to 200,000. After the coating material according to claim 2 or 3 is applied on the translucent substrate, a hard coat layer obtained by curing the coating material with energy is laminated, and the metal oxide fine particles are formed in the hard coat layer. An optical laminated body characterized by being dispersed substantially uniformly. A method for producing metal oxide fine particles, comprising: performing a surface treatment of metal oxide fine particles; and a step of mixing the metal oxide fine particles surface-treated in the above step with an organic polymer compound.

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