JP2009196286A - Anti-glare member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-glare member in which an anti-glare layer formed from a coating composition having dispersion stability is laminated, and which has excellent glare proofing properties, abrasion resistance, chemical resistance, haze resistance and optical transmissivity required for a display surface layer. <P>SOLUTION: The anti-glare member is formed of a coating composition containing hydrophobic silica particles (A) with the average secondary particle diameter of 0.5 to 3.5 μm and a transparent resin (B) on at least either one face of a transparent base material, and has a flat part and a projecting part derived from the hydrophobic silica particles (A). Wherein, the thickness of a hardened film in the flat part is 0.3 to 12 μm, and the surface of the projecting part is covered with the hardened matter of the transparent resin (B). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to various displays such as liquid crystal displays, plasma displays, EL displays, rear projection displays, and CRT displays used as image display devices for televisions, computers, car navigation systems, in-vehicle instrument panels, mobile phones and the like. The present invention relates to an antiglare member provided to prevent reflection of an image or reflection of light on a surface.

  The surface of the display is generally subjected to an antiglare treatment in order to prevent the visibility from being deteriorated due to reflection of light incident from the outside or reflection of the operator himself. In addition, scratch resistance and chemical resistance are also required to prevent scratches on the display surface. Specifically, for example, it is known to provide a cured coating film using a coating composition containing a light diffusing agent and a transparent resin on one surface of a transparent substrate such as triacetyl cellulose (TAC). .

  The light diffusing agent also has a function of increasing haze to prevent glare caused by incident light, for example, inorganic powders such as silica, calcium carbonate, precipitated barium sulfate, organic particles such as polyethylene particles, polymethyl methacrylate particles, and polycarbonate particles. It was appropriately selected from fine particles and the like. Among these, silica powder has a characteristic that it does not hinder the curing of the active energy ray-curable resin contained in the transparent resin, since the silica powder has high transmittance to ultraviolet rays. Then, in order to improve the dispersibility to the transparent resin containing active energy ray hardening resin with respect to a silica, processing the surface of a silica powder with organic substance is performed (refer patent documents 1-3).

However, a coating film using silica treated with an inorganic substance has low chemical resistance, and whitening may occur depending on the chemical used. Similar to silica, the chemical resistance was poor and sometimes whitened. Silica surface-treated with an alkoxide compound, a silane coupling agent, chlorosilane, etc. has excellent chemical resistance and good transparency as shown in Examples of use in Patent Documents 6 and 7. The glare effect was low, and the required physical properties were not fully satisfied.
Moreover, the coating composition in which silica is dispersed in a transparent resin has a problem in dispersion stability because silica settles in a short time.
Japanese Patent Publication No. 63-40282 Japanese Examined Patent Publication No. 4-65095 JP-A-5-162261 JP 11-209717 A JP 2002-169001 A Japanese Patent Publication No.62-21815 Japanese Patent Publication No. 2-60696 JP-A-8-3476

  In the present invention, an antiglare layer formed from a coating composition having excellent dispersion stability is laminated, and the antiglare, scratch resistance, chemical resistance, haze and light transmittance required for a display surface layer are laminated. Is intended to provide an anti-glare member.

That is, the first invention is a coating composition comprising hydrophobic silica particles (A) having an average secondary particle diameter of 0.5 to 3.5 μm and a transparent resin (B) on at least one surface of a transparent substrate. An antiglare layer formed from a product, having a flat portion and a protruding portion derived from the hydrophobic silica particles (A), and having an antiglare layer with a cured film thickness of 0.3 to 12 μm of the flat portion. A dazzling member,
It is related with the glare-proof member characterized by the surface of the said protrusion part being covered with the hardened | cured material of transparent resin (B).

  Moreover, 2nd invention is related with the glare-proof member of 1st invention whose protrusion height of the glare-proof layer surface is 0.1 micrometer-2 micrometers from the flat part of a glare-proof layer.

  Moreover, 3rd invention is related with the glare-proof member of 1st or 2nd invention, wherein transparent resin (B) contains active energy ray-curable resin (b).

  The fourth invention relates to the antiglare member of the third invention, wherein the active energy ray-curable resin (b) contains an active energy ray-curable resin having an isocyanurate ring.

  Moreover, 5th invention is related with the glare-proof member of 3rd or 4th invention, wherein transparent resin (B) consists only of active energy ray hardening resin (b).

  According to the present invention, by using the coating composition whose dispersion stability is improved by the hydrophobic silica particles, the cured film of the transparent resin covers the protrusions derived from the hydrophobic silica particles formed on the surface of the member. By making the best use of the hardness of the transparent resin after curing, it was possible to provide an antiglare member having good scratch resistance and excellent chemical resistance, haze and light transmittance.

A preferred embodiment of the present invention will be described.
As the transparent substrate in the present invention, a plastic film having excellent visible light transmittance (preferably a light transmittance of 90% or more) and transparency (preferably having a haze value of 1% or less) can be used. Specifically, for example, a film made of a transparent polymer such as a polyester polymer such as polyethylene terephthalate and polyethylene naphthalate, a cellulose polymer such as diacetyl cellulose and triacetyl cellulose, a polycarbonate polymer, and an acrylic polymer such as polymethyl methacrylate. Is mentioned. Styrene polymers such as polystyrene and acrylonitrile / styrene copolymers, polyethylene, polypropylene, polyolefins having a cyclic or nobornene structure, olefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, nylon and aromatic polyamides Examples thereof include a film made of a transparent polymer such as an amide polymer. Furthermore, imide polymers, sulfone polymers, polyether sulfone polymers, polyether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxy The film etc. which consist of transparent polymers, such as a methylene-type polymer, an epoxy-type polymer, and the said polymer blend, etc. are mentioned.
Among these, those having particularly low optical birefringence are preferable, and a film made of triacetyl cellulose (TAC) is more preferable.

The coating composition in the present invention includes hydrophobic silica particles (A) and a transparent resin (B).
As the hydrophobic silica particles (A), those obtained by organically treating precipitated silica obtained by reacting alkali metal silicate and mineral acid with silicone oil or the like are preferably used, and the pH when suspended at 4% is 6%. It is preferable that the apparent specific gravity is 0.16 to 0.27 g / ml, and the dibutylamine adsorption amount is 3 to 40 mmol / kg.

  When the pH at the time of 4% suspension is less than 6.5, chemical resistance of the coating film, particularly alkali resistance, for example, resistance to NaOH is deteriorated, and when it exceeds 8.5, acid resistance is deteriorated.

  When the apparent specific gravity is less than 0.16 g / ml, it is difficult to uniformly disperse and the viscosity of the coating liquid increases. If it exceeds 0.27 g / ml, the silica is liable to settle, and there is a risk that defects in the transparency of the coating film occur.

  If the dibutylamine adsorption amount is less than 3 mmol / kg, the hydrophobicity of the silica particle surface becomes too strong, so that the silica particles tend to agglomerate with each other, and if it exceeds 40 mmol / kg, the hydrophilicity becomes strong. The affinity with (B) is poor, and a dispersion having good stability cannot be obtained.

The alkali metal silicate used in the above reaction is preferably sodium silicate. Examples of the mineral acid include sulfuric acid, hydrochloric acid and phosphoric acid. Examples of the silicone oil used for treating the precipitated silicic acid include dimethyl silicone oil, methyl phenyl silicone oil, methyl hydrogen silicone oil, and methyl biphenyl silicone oil. The mixing treatment of the precipitated silicic acid and the silicone oil may be of any type as long as it is an ordinary mixer, but since the fine powder (precipitated silicic acid) and the liquid (silicone oil) are mixed, It is preferable to use a mixing apparatus that does not generate aggregated particles due to adhesion. Examples of such an apparatus include a ball mill and a fluid mixer. Such hydrophobic silica particles (A) used in the present invention can be obtained from the market under trade names such as [Nip seal, SS grade] (manufactured by Tosoh Silica Co., Ltd.).
The coating composition containing such hydrophobic silica particles (A) has excellent dispersion stability, and the silica particles do not settle with time, and the dispersion stability is good. Furthermore, it was found that an antiglare layer having excellent scratch resistance, chemical resistance and antiglare property can be obtained by applying this coating composition to a transparent substrate, but this was not expected at all. It is an effect.

The hydrophobic silica particles (A) preferably have an average secondary particle diameter of 0.5 to 3.5 μm, more preferably 1 to 3.0 μm from the viewpoint of improving transparency in addition to antiglare properties. . When the thickness is less than 0.5 μm, the surface gloss of the resulting antiglare layer becomes high and the antiglare effect cannot be obtained, and when it is more than 3.5 μm, the antiglare property may be excessive. In general, the smallest particles constituting the powder are referred to as primary particles, and the state where the primary particles are aggregated is referred to as secondary particles. For this reason, the powder of inorganic fine particles often exists as secondary particles, and the hydrophobic silica particles (A) also take the form of irregular secondary particles in which primary particles are aggregated. The average secondary particle diameter of the hydrophobic silica particles (A) is a numerical value obtained by measuring the secondary particles with a measuring machine. Specifically, a Coulter Multisizer (Beckman Coulter Co., Ltd.) was used as a measuring device, and the aperture size was measured at 30 μm by the Coulter method.
0.1-50 weight part is preferable with respect to 100 weight part of transparent resin (B), and, as for the usage-amount of hydrophobic silica particle (A), 1-30 weight part is more preferable.

  In addition to the hydrophobic silica particles (A), translucent fine particles other than the hydrophobic silica particles (A) can also be used in order to adjust the antiglare property and transparency. The translucent fine particles form protrusions on the surface of the antiglare layer, or scatter light inside the antiglare layer to impart antiglare properties, and use organic fine particles and / or inorganic fine particles. Can do. These translucent fine particles may be a combination of two or more kinds of particles in order to control surface protrusion and refractive index. By blending two or more kinds of translucent fine particles, optical characteristics such as haze value required for various applications can be arbitrarily adjusted.

  Among the translucent fine particles, organic fine particles include, for example, styrene beads, acrylic beads, styrene-acrylic beads, melamine beads, benzoguanamine beads, polycarbonate beads, polyethylene beads, silicone beads, fluorine beads, vinylidene fluoride beads, and vinyl chloride beads. , Epoxy beads, nylon beads, phenol beads, polyurethane beads and the like. As for the particle diameter of these organic fine particles, the average particle diameter of primary particles is preferably 0.1 to 10 μm, and more preferably 2 to 6 μm. If the average particle diameter of the primary particles is less than 0.1 μm, the anti-glare property obtained is insufficient because the light scattering effect is insufficient, and if it exceeds 10 μm, the light scattering effect inside the anti-glare layer decreases. Therefore, it is easy to produce glare of an image. The amount of the organic fine particles used can be 0 to 10 parts by weight with respect to 100 parts by weight of the transparent resin (B). The average particle diameter of the primary particles is measured by a dynamic light scattering method using Nanotrac UPA-150EX (manufactured by Nikkiso Co., Ltd.) as a measuring instrument.

  Examples of the inorganic fine particles in the present invention include titanium dioxide particles, zirconium oxide particles, and aluminum oxide particles other than the hydrophobic silica particles (A). The average secondary particle diameter of these inorganic fine particles is preferably 0.5 to 3 μm, and more preferably 0.5 to 2 μm. The shape of these inorganic fine particles may be indefinite or spherical. The amount of the inorganic fine particles used can be 0 to 10 parts by weight with respect to 100 parts by weight of the transparent resin (B). The average secondary particle diameter of the inorganic fine particles in the present invention is measured by a dynamic light scattering method using Nanotrac UPA-150EX (manufactured by Nikkiso Co., Ltd.) as a measuring instrument.

  The dispersion of the hydrophobic silica particles (A) and the light-transmitting fine particles used as necessary in the transparent resin (B) can be performed by a known method until the coating composition is sufficiently uniform. There is no restriction | limiting in particular as a disperser used in order to disperse | distribute, For example, well-known dispersers, such as a kneader, a roll mill, an attritor, a super mill, a dissolver, a homomixer, a sand mill, can be used.

  The transparent resin (B) preferably contains an active energy ray-curable resin (b). The active energy ray-curable resin (b) is a compound having an ethylenically unsaturated double bond, and a known compound can be used. The ethylenically unsaturated double bond is preferably an acryloyl group or a methacryloyl group. Specific examples of such compounds include a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate containing 3 to 4 ethylenically unsaturated double bonds, and 6 ethylenically unsaturated double bonds. Preferred are urethane acrylate oligomers containing from 15 to 15, and compounds containing three ethylenically unsaturated double bonds and having an isocyanurate ring, and these may be used in combination. A compound having three ethylenically unsaturated double bonds and having an isocyanurate ring is more preferable from the viewpoints of less curing shrinkage and less curling of the member and good scratch resistance.

  The transparent resin (B) can also contain an active energy ray-curable resin (b) other than those exemplified above. Specifically, it is a compound having 1 to 6 ethylenically unsaturated double bonds. For example, by including a compound having one ethylenically unsaturated double bond, the viscosity of the coating composition such as fluidity can be increased. Scratch resistance can be improved by adjusting and including a compound having six ethylenically unsaturated double bonds, but is not limited thereto, and has a known ethylenically unsaturated double bond Compounds can be used.

  The transparent resin (B) can also include a resin that is not cured by active energy rays such as an acrylic resin, an epoxy resin, or a urethane resin. However, since the scratch resistance may be lowered, the active energy ray curable resin ( Preferably it contains only b).

  When the coating composition is cured with ultraviolet rays, it preferably contains a photopolymerization initiator. The type of the photopolymerization initiator is not particularly limited, and examples thereof include acetophenones, benzoins, benzophenones, anthraquinones, phosphine oxides, ketals, anthraquinones, thioxanthones, and the like. Specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, methylanthraquinone, 2-ethylanthraquinone, 2-aminoanthraquinone, 2,4,6-trimethylbenzoindiphenylphosphine oxide, Michler's ketone, isoamyl N, N-dimethylaminobenzoate, thioxan, 2-chlorothioxanthone 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, etc., and two or more of these photopolymerization initiators can be used in combination as appropriate.0.1-20 weight part is preferable with respect to 100 weight part of active energy ray-curable resins (b), and, as for the usage-amount of these photoinitiators, 1-10 weight part is more preferable.

The coating composition may contain a solvent, but when triacetylcellulose is used as the transparent substrate, the solvent that dissolves or swells triacetylcellulose for the purpose of improving the adhesion of the antiglare layer to the transparent substrate. And an organic solvent that does not dissolve or swell is preferably used in combination.
Examples of the organic solvent that dissolves or swells the transparent substrate of triacetyl cellulose include, for example, dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane. Ethers such as tetrahydrofuran, anisole, phenetole; ketones such as acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone; ethyl formate, propyl formate, pentyl formate, methyl acetate, Esters such as ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, γ-ptyrolactone; other methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, 2-ethoxy Examples include ethyl propionate, 2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, and ethyl acetoacetate. These can be used alone or in combination of two or more.

Examples of the organic solvent that does not dissolve or swell the transparent triacetyl cellulose substrate include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol, isobutyl acetate, methyl isobutyl ketone, 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol, hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene, xylene However, it is not limited to these. These can be used alone or in combination of two or more.
The organic solvent that dissolves or swells triacetyl cellulose is preferably used in an amount of 10 to 40 parts by weight when the total amount of the solvent is 100 parts by weight. When the amount is less than 10 parts by weight, the adhesion of the antiglare layer to triacetyl cellulose may be insufficient. If it exceeds 40 parts by weight, dissolution and swelling will be excessive, and the transparency and visibility of the antiglare member may be reduced. In addition, when using transparent base materials other than a triacetyl cellulose, the well-known solvent selected suitably can be used.

  The coating composition preferably further contains a pigment dispersant for the purpose of further improving the dispersion stability of the hydrophobic silica particles (A). As the pigment dispersant, a pigment dispersant made of a polyester resin, an acrylic resin, a urethane resin, or the like can be used, and those made of a resin having a basic functional group such as an amino group in the molecule are preferable. The amount of the pigment dispersant used is preferably 1 to 50 parts by weight and more preferably 3 to 30 parts by weight with respect to 100 parts by weight of the hydrophobic silica particles (A).

  The coating composition can also contain various additives within a range that does not affect various physical properties such as antiglare property and scratch resistance.

The active energy ray in the present invention means an electromagnetic wave having a wavelength capable of reacting with a photopolymerization initiator or an ethylenically unsaturated double bond, and examples thereof include an electron beam, ultraviolet rays, visible light, radiation, and γ rays. Examples of the ultraviolet irradiation device include metal halide lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultrahigh-pressure mercury lamps, electrodeless lamps, xenon lamps, semiconductor lasers, argon lasers, carbon arc lamps, tungsten lamps, pulsed UV lamps, and the like. It is done. As the electron beam irradiation device, a thermionic emission gun, a field emission gun, or the like can be used. Dose, although in the case of ultraviolet can be suitably set within a range of 5~2000mJ / cm ^2, a range of administrative steps likely 50~1000mJ / cm ² is more preferable. In the case of an electron beam, 20 to 2000 KeV is preferable. Further, ultraviolet rays or electron beams can be used in combination with infrared rays, far infrared rays, hot air, high-frequency heating, or the like.

The antiglare member of the present invention is applied to the hydrophobic silica particles (A) by coating the coating composition on a transparent substrate, drying the solvent as necessary, and further curing by irradiation with active energy rays or the like. It can be produced by providing an antiglare layer having a protruding part derived from the flat part and having a cured film thickness of 0.3 to 12 μm, preferably 3 to 7 μm. The surface of the protrusion is covered with a cured product of the transparent resin (B).
Moreover, it is preferable that the height of the said protrusion part is 0.1 micrometer-2 micrometers from the flat part of a glare-proof layer. When the thickness is less than 0.1 μm, the antiglare property may be insufficient. When the thickness exceeds 2 μm, the light scattering effect inside the antiglare layer is reduced, which may cause glare. The number of protrusions having a protrusion height of 0.1 μm to 2 μm preferably occupies 10% or more of the total number of protrusions, and more preferably 30% or more. If it is less than 10%, the antiglare property may be insufficient.

  The coating composition is preferably a solvent-based composition that does not intentionally contain water-based raw materials. In this case, the wettability of the transparent resin (B) to the surface of the hydrophobic silica particles (A) becomes extremely good, and the surface can be more reliably covered. When the transparent resin (B) is cured after drying, the surface of the protruding portion derived from the hydrophobic silica particles (A) is covered and fixed by the cured film of the transparent resin (B). As a result, since the antiglare layer can realize uniform surface hardness derived from the cured product of the transparent resin (B), hard coat properties such as a scratch resistance test are improved. Further, for example, when used as an antiglare member on the surface of a liquid crystal display, the hydrophobic silica particles (A) are not directly exposed to the surface of the antiglare layer, so that hydrophobic silica can be removed when wiping off dirt adhered to the surface. There is also an effect that quality deterioration such as anti-glare property can be prevented by dropping the particles (A).

  Examples of the coating method include a Mayer bar method, a blade method, a spin coating method, a reverse method, a die coating method, a spray coating method, a roll coating method, a gravure coating method, a micro gravure coating method, a lip coating method, and an air knife coating. A known coating method such as a method or a dipping method can be used.

  Thus, on the transparent substrate, the surface of the present invention produced by forming a glare-proof layer having a protrusion derived from hydrophobic silica particles and the protrusion being covered with a cured coating of a transparent resin. The antiglare member preferably has an optical characteristic with a total light transmittance of 85% or more and a haze value of 3 to 60%, and has a total light transmittance of 90% or more and a haze value of 4 to 45%. More preferably, it has optical characteristics. If the total light transmittance is less than 85%, it is difficult to display an image with high contrast. When the haze value is less than 3%, the antiglare property is insufficient, and when it exceeds 60%, white blurring may occur. Note that white blur means that the display screen becomes whitish when displaying black when used in a liquid crystal display due to light scattering.

  In order to further improve the contrast and white blurring of the screen display on the surface of the antiglare layer of the antiglare member, a low refractive index layer having a refractive index lower than that of the antiglare layer can be provided. As these low refractive index layers, for example, those having a polysiloxane structure are used, and those having a fluorine-containing polysiloxane structure are preferred. The low refractive index layer can be formed of, for example, fluorine-containing alkoxysilane. The thickness of the low refractive index layer is preferably 0.05 to 0.15 μm. The low refractive index layer can be formed on the surface of the antiglare layer by an appropriate method. As a coating method, the same method as the production of the antiglare member can be used.

  EXAMPLES The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight”.

[Synthesis Example 1]
In a reactor equipped with a stirrer, thermometer and Dean-Stark apparatus, 27.2 parts of pentaerythritol, 63.4 parts of acrylic acid, 100 parts of toluene, 3 parts of acidic catalyst paratoluenesulfonic acid and polymerization inhibitor hydroquinone monomethyl ether 0 0.08 parts was charged and then heated with blowing air and stirring. The mixture was refluxed for 7 hours to distill 14.2 parts of water. After completion of the reaction, 50 parts of a 10% aqueous sodium hydroxide solution was added to the reaction solution, and the mixture was stirred at room temperature and allowed to stand. The lower layer (aqueous layer) was separated, and excess acrylic acid was removed. The reaction solution was washed with water until the aqueous layer was neutralized. This was dried over anhydrous sodium sulfate, 0.028 part of hydroquinone monomethyl ether was added, and toluene was distilled off under reduced pressure and concentrated. This solution was treated with silica gel column-mobile phase toluene, 0.02 part of hydroquinone monomethyl ether was added, and the solvent was distilled under reduced pressure with toluene.
As described above, 61 parts of pentaerythritol tetraacrylate containing a slight amount of pentaerythritol triacrylate as a by-product was obtained. When measured by gas chromatography / 13C-NMR, the weight ratio of pentaerythritol tetraacrylate to pentaerythritol triacrylate was 99: 1.

"Gas chromatograph measurement conditions"
Equipment: SHIMAZDU GCMS-QP5050A
Column: DB-5 0.25IDmm × 30m df = 0.25mm
Detection temperature: 250 ° C
Injection temperature: 150 ° C
Oven temperature: 50 ° C. hold for 1 minute-temperature rising rate 10 ° C./min-250° C.

[Example 1]
As active energy ray-curable resin (b), 97 parts of pentaerythritol tetraacrylate obtained in Synthesis Example 1 and 3 parts of Aronix M306 (manufactured by Toagosei Co., Ltd .: mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate) And 5 parts of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) were added, and the mixture was stirred with a high-speed disper at 2000 rpm for 5 minutes. Furthermore, 1.5 parts of a basic pigment dispersant (BYK168, manufactured by Big Chemie) was added to this solution, and hydrophobic silica particles (manufactured by Tosoh Silica, NIPSIL SS-50B, pH at the time of 4% suspension was 7.6). 10 parts of an apparent specific gravity of 0.2 g / ml, an adsorption amount of dibutylamine of 10 mmol / kg, and an average secondary particle size of 2.1 μm) were added, and the mixture was stirred for 30 minutes at 4000 rpm with a high-speed disper. A composition was obtained.
Further, the coating composition was applied to a 80 μm thick triacetyl cellulose film (Fuji Film Co., Ltd.) with a bar coater and dried with hot air at 70 ° C. for 1 minute. Thereafter, under a nitrogen purge atmosphere (oxygen concentration of 0.3% by weight or less), ultraviolet rays were irradiated at a dose of 400 mJ / cm ² using a high-pressure mercury lamp to form an antiglare layer having a cured film thickness of 4 μm on the flat part. An antiglare member having was obtained.

  The cured film thickness of the flat part was measured with a digital micro film thickness meter (made by Nikon Corporation), and the protruding height was a photograph of a part of the anti-glare member taken with an electron microscope (S-4300 made by Hitachi, Ltd.). Is used to express the difference between the film thickness of the protrusion and the film thickness of the flat part. Moreover, from the said photograph, it was evaluated whether the protrusion part derived from hydrophobic silica (A) was covered with the transparent resin (B).

[Example 2]
Anti-glare performed in the same manner as in Example 1 except that the active energy ray-curable resin (b) of Example 1 was changed to purple light UV-1700B (manufactured by Nippon Gosei Co., Ltd., urethane acrylate oligomer having 10 acryloyl groups). A member was obtained.

[Example 3]
The same as in Example 1 except that the active energy ray-curable resin (b) of Example 1 was changed to Aronics M315 (manufactured by Toagosei Co., Ltd., a compound containing three acryloyl groups and having an isocyanurate ring). A dazzling member was obtained.

[Example 4]
Except that 2 parts by weight of translucent organic fine particles (manufactured by Sekisui Chemical Co., Ltd., average primary particle size 3.5 μm, crosslinked polystyrene-methyl methacrylate particles XX-12AE) were further added to the coating composition of Example 1. An antiglare member was obtained in the same manner as in Example 1.

[Comparative Example 1]
The hydrophobic silica particles (A) of Example 1 were separated from another hydrophobic silica (NIPSIL SS70, manufactured by Tosoh Silica Co., Ltd. with a pH of 7.5 when suspended, 7.5, an apparent specific gravity of 0.38 g / ml, An antiglare member was obtained in the same manner as in Example 1 except that the butylamine adsorption amount was changed to 11 mmol / kg and the average secondary particle size was changed to 5.1 μm.

  In addition, when the total light transmittance of the anti-glare member of Examples 1-4 and the comparative 1 was measured using the haze meter NDH-2000 (made by Nippon Denshoku), all were 85% or more.

[Dispersion stability] The coating composition was allowed to stand at 25 ° C, and the presence or absence of fine particle precipitation after 7 days was visually determined.
○: Good. X: There is precipitation.

[Haze Value] The haze value was measured using a haze meter NDH-2000 (manufactured by Nippon Denshoku).

[Pencil hardness] Measured according to JIS K5400.

[Adhesion test] Evaluation was made by the cross-cut tape method (total cross-cut number of 100 pieces, 1 mm interval) according to JIS K5400. The evaluation results are expressed in fractions by the number of non-peeled crosscuts / total crosscuts.
Example) 100/100: No dropout, 50/100: 50 pieces dropped out, and 50 pieces remained.

[Adhesion test after light resistance test] 63 ° C.-45% RH-65 mW / cm ² -using a super UV light resistance tester (Dipler metal weather, model: KU-R5CI-A, light source: metal halide lamp) After carrying out the light resistance test under the condition of 24 hours, an adhesion test was carried out by a cross-cut tape method (interval 1 mm) in accordance with JIS K5400.

[Abrasion resistance] Using steel wool # 0, the surface state was visually evaluated by reciprocating 500 g / 10.
A: Very good.
○: Good.
Δ: Slightly inferior.
X: Inferior.

[Anti-Glare] An exposed fluorescent lamp without a louver was copied on the anti-glare layer of the anti-glare member, and the degree of blur of the reflected image was visually evaluated.
A: The outline of the fluorescent lamp is not known at all.
○: The outline of the fluorescent lamp is slightly understood.
Δ: The fluorescent lamp is blurred but the outline can be identified.
X: The fluorescent lamp is hardly blurred (no antiglare property).

[Chemical resistance] The following chemicals were dropped on the surface of the antiglare layer, left standing for a predetermined time, wiped off, and the surface change state was visually evaluated.
Chemical 3N-NaOH: Leave for 15 minutes after dropping.
1N HCl: Leave for 15 minutes after dropping.
Various organic solvents: Leave for 10 hours after dropping.
Evaluation criteria ○: No change. X: Whitening.

[Comprehensive evaluation] A product that can be used as an anti-glare member was evaluated as “◯”, and a product that could not be used as “×”.

<Evaluation results>
The evaluation results are shown in Table 1.

  From the results of Table 1, Comparative Example 1 does not satisfy all the evaluation items, and it is considered difficult to use as an antiglare member. Examples 1 to 4 have good physical properties such as scratch resistance, chemical resistance, haze, and light transmittance required as an antiglare member, and satisfy the dispersion stability required as a coating composition. Met. Accordingly, the antiglare member of the present invention can be suitably used as a surface layer for various displays.

Cross section of anti-glare member

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hydrophobic silica particle 2 ... Hardened | cured material of transparent resin 3 ... Transparent base material 4 ... Projection part 5 ... Flat part

Claims (5)

Formed on the at least one surface of the transparent substrate from a coating composition containing hydrophobic silica particles (A) having an average secondary particle size of 0.5 to 3.5 μm and a transparent resin (B), and a flat portion; And an antiglare member having a protrusion derived from the hydrophobic silica particles (A), and provided with an antiglare layer having a cured film thickness of 0.3 to 12 μm of the flat portion,
An anti-glare member, wherein a surface of the protruding portion is covered with a cured product of a transparent resin (B).   The antiglare member according to claim 1, wherein the protrusion height of the surface of the antiglare layer is 0.1 μm to 2 μm from the flat portion of the antiglare layer.   The antiglare member according to claim 1, wherein the transparent resin (B) contains an active energy ray-curable resin (b).   The anti-glare member according to claim 3, wherein the active energy ray-curable resin (b) contains an active energy ray-curable resin having an isocyanurate ring.   The antiglare member according to claim 3 or 4, wherein the transparent resin (B) comprises only the active energy ray-curable resin (b).