JP2006039007A - Antireflection member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection member having satisfactory stainproofing performance and alkali resistance. <P>SOLUTION: In the antireflection member made by forming an antireflection layer comprising a low refractive index layer and an stainproofing layer on a base material, contact angle of a stainproofing layer with respect to water is 100° or more and the contact angle with respect to oleic acid is 70° or more. In such a manner, when 1% NaOH aqueous solution is dropped on the stainproofing layer and is left standing for 1 hr and then the dropped part of the stainproofing layer is cleaned and dried, the constant angle of the stainproofing layer with respect to water is 100° or more. As a result, the antireflection member which has excellent alkali resistance and hardly causes a change in the lapse of time can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antireflection member used for a display device or the like.

  Antireflection films are applied to display devices such as liquid crystal displays, cathode ray tube display devices, and plasma display panels. Since the antireflection film is located at the forefront when used in a display device, it may be contaminated by dust or oil floating in the atmosphere, fingerprints by human hands, oil, and the like.

  Therefore, it is known to provide an antifouling layer such as a fluorine compound or an alkylsilane compound on the outermost surface of the antireflection film (see Patent Documents 1 and 2).

However, these antifouling layers are poor in alkali resistance even though they are sufficiently satisfied with antifouling properties. Specifically, when the antireflection film is made of a metal oxide, there are problems such as deterioration due to alkali and destruction of the interface between the metal oxide layer and the antifouling layer.
Japanese Patent Laid-Open No. 10-195417 JP 2001-048590 A

  An object of the present invention is to provide an antireflection member having sufficient antifouling performance and alkali resistance.

  The invention according to claim 1 is an antireflection member formed by forming an antireflection layer including a low refractive index layer and an antifouling layer on a substrate, and the contact angle of the antifouling layer to water is 100 ° or more. And a contact angle with respect to oleic acid is 70 ° or more.

  The invention according to claim 2 is characterized in that after the 1% NaOH aqueous solution of the antifouling layer is dropped and allowed to stand for 1 hour, the contact angle with respect to water after washing and drying the dripping part is 100 ° or more. The antireflection member according to claim 1.

  A third aspect of the present invention is the antireflection member according to the first or second aspect, wherein the low refractive index layer comprises two layers.

  The invention according to claim 4 is characterized in that, among the two low refractive index layers, the low refractive index layer on the antifouling layer side is denser than the low refractive index on the substrate side. It is an antireflection member.

  The invention according to claim 5 is the antireflection member according to any one of claims 1 to 4, wherein the antireflection layer includes a high refractive index layer and / or a medium refractive index layer.

  Invention of Claim 6 has 1 or more types of layers chosen from a hard-coat layer, an antistatic layer, and a glare-proof layer between a base material and an anti-reflective layer of Claims 1-5 characterized by the above-mentioned. The antireflection member according to any one of the above.

  The invention according to claim 7 is a polarizing plate including the antireflection member according to any one of claims 1 to 6.

  The invention according to claim 8 is a display device comprising the antireflection member according to any one of claims 1 to 6 or the polarizing plate according to claim 7.

  In the present invention, an antifouling layer is provided on a functional film including a metal layer and / or a metal oxide layer such as an optical film via an antifouling base layer, thereby providing excellent alkali resistance and water repellency, oil repellency, It is excellent in fingerprint and oil-based ink wiping properties and can be made into a laminate showing good antifouling performance.

  In addition, the alkali resistance is resistant to changes over time and is excellent in heat and moisture resistance.

  As a base material used in the present invention, a plastic base material such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), triacetyl cellulose (TAC), a glass base material, or a polarizing plate is used. It can be used as a substrate.

  Furthermore, a known additive, for example, an ultraviolet absorber, a plasticizer, a lubricant, a colorant, an antioxidant, a flame retardant and the like may be contained.

  Moreover, it is preferable that the base material surface is previously subjected to etching treatment such as sputtering treatment, corona treatment, flame treatment, ultraviolet ray irradiation and electron beam irradiation, and undercoating treatment. If the said process is given to the surface of a base material, the adhesiveness with respect to another adjacent layer can be improved.

  In addition, if necessary, the surface of the base material may be subjected to a dustproof treatment such as solvent cleaning or ultrasonic cleaning.

  In the present invention, an antireflection material having alkali resistance and excellent antifouling performance can be obtained by densifying the low refractive index layer on the surface side in contact with the antifouling layer.

  The antireflection layer of the present invention includes at least a low refractive index layer, and may be a dense single layer of a low refractive index layer, or a combination of a plurality of low refractive index layers and high refractive index layers or medium refractive index layers. The side low refractive index layer may be dense.

  Further, the low refractive index layer on the antifouling layer side may be composed of two layers, and the low refractive index layer on the surface side in contact with the antifouling layer may be made dense.

  Here, as the configuration of the antireflection layer, for example, a low refractive index layer single layer or a combination of a layer having a plurality of different refractive indexes, such as a low refractive index layer, a high refractive index layer, a middle refractive index layer, and the like. It is done.

  Here, an example of a layer structure is shown in FIGS.

  The structure of the antireflection layer in which a plurality of layers having different refractive indexes is laminated is a combination of a layer having a relatively high refractive index or a layer having a low refractive index alternately with respect to the front layer on the substrate side, In the structure of base material / high refractive index layer / low refractive index / high refractive index layer / low refractive index, the optical film thickness is (base material) / (about λ / 8) / (about λ / 8 from the base material side. ) / (About λ / 4) / (about λ / 4). However, in this case, λ (nm) is a wavelength for which an antireflection effect is desired.

  The medium refractive index layer is composed of a base material / medium refractive index layer / high refractive index layer / low refractive index layer, and the optical film thickness is (base material) / (about λ from the base material side. / 4) / (about λ / 8) / (about λ / 4). However, in this case, λ (nm) is a wavelength for which an antireflection effect is desired.

  Of these low refractive index layers, the low refractive index layer on the antifouling layer side (surface side) consists of a dense single layer or two layers, and the surface side is made dense.

  The low refractive index layer provided on the dense low refractive index layer or antifouling layer side is not particularly limited as long as it is dense and has a refractive index of 1.2 to 1.6. Can be suitably used.

  As such a thing, silicon oxide is mentioned.

  The method of forming the low refractive index layer provided on the dense low refractive index layer or antifouling layer side is not particularly limited, but in order to obtain a dense film as described above, the following coating method or vapor phase is used. The method is preferably used.

  As a coating method, a coating solution containing the following raw materials is applied and cured.

As a raw material, a raw material made of a silicon alkoxide compound represented by Si (OR) ₄ (R: organic functional group) or an organosilane compound made of R′Si (OR) ₃ (R, R ′: organic functional group) Can be used.

Examples of the silicon alkoxide compound include compounds represented by Si (OC _n H _{2n + 1} ) ₄ (n: a natural number of 1 to 10), and examples of the organosilane compound include (C _m H _{2m + 1} ) Si (OC _n H _{2n + 1} ) ₄ (m, n: a natural number of 1 to 10), and the like.

  It can form by apply | coating and hardening using the liquid mixture of these raw materials and a solvent. As a solvent, 1 type chosen from water, ethanol, propanol, butanol, alcohols, such as isobutyl alcohol, methyl cellosolve, etc., or those combinations can be used. Moreover, phosphoric acid etc. can be added as a hydrolysis initiator.

  Further, ammonia or phosphoric acid may be added as a pH adjusting agent to adjust the pH.

  Moreover, as a curing method, it can be cured by applying energy such as drying, heat, ionizing radiation, or plasma.

  Here, as a material of the low refractive index layer provided on the dense low refractive index layer or the antifouling layer side, the silicon alkoxide compound and the organosilane compound may be used alone or in combination. . In either case, the dense low refractive index layer or the low refractive index layer provided on the antifouling layer side is formed with a dense matrix composed of Si-O-Si bonds, and the antifouling layer is densely formed thereon. The In the case of using an organometallic compound, the organic functional group R ′ remains in the underlayer, so that the antifouling layer does not bind to the organic layer, but the organic functional group R ′ exhibits water repellency and oil repellency, The antifouling functional group of the antifouling material existing close to the group R ′ is formed densely on the matrix and exhibits antifouling properties and alkali resistance.

  In the case of using a vapor phase method, it is preferable to use a chemical vapor deposition method (CVD method), which can be obtained by performing a decomposition reaction of a source gas, oxygen gas, dilution gas, or the like with plasma to form a film.

  As the source gas, the aforementioned materials can be vaporized and used.

  When the film is formed by the CVD method, the electric power applied between the electrodes changes depending on the electrode area, so it can be arbitrarily set according to the electrode area, and the film can be formed by discharging at a pressure of 1 to 100 Pa. it can.

  As the low refractive index layer on the base material side when the low refractive index layer is composed of two layers or the low refractive index layer on the base material side when the multilayer antireflection film is used, the refractive index n = 1.2 to 1.6. Examples thereof include silicon oxide, magnesium fluoride, and calcium fluoride.

  The high refractive index layer is not particularly limited as long as it has a refractive index of 1.8 to 2.6, and a metal oxide material can be suitably used.

  Examples of such a material include titanium oxide, zirconium oxide, zinc oxide, indium oxide, tin oxide, and a composite oxide of indium oxide and tin oxide.

  As the middle refractive index layer, the refractive index n = 1.6 to 1.9, the middle refractive index layer is aluminum oxide, cerium fluoride, or an inorganic binder having a higher refractive index than that of the binder. A method of dispersing the system particles, specifically, for example, using silicon oxide as a binder and dispersing titanium oxide having a higher refractive index than silicon oxide in the binder silicon oxide, and the like.

  A method for forming these materials is not particularly limited, and can be provided by a known method such as a gas phase method or a coating method.

  As the vapor phase method, various film formation methods represented by an evaporation method, an ion plating method, an ion beam assist method, a sputtering method, and a CVD method can be used.

  From the viewpoint of film formation speed, it is preferable to use a vapor deposition method, an ion plating method, an ion beam assist method, or a sputtering method.

  When the coating method is used, it can be formed by applying and curing a solution containing a metal alkoxide.

  The antifouling layer of the present invention is not particularly limited as long as it has water repellency, oil repellency, and low friction properties, and examples thereof include those composed of a fluorine-containing silicon compound.

Examples of fluorine-containing silicon compounds include:
_{R f - (CH 2) n} -Si- (OR) 3
(R _f : linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, R: organic functional group, n: natural number)
Silane compounds such as fluoroalkylsilane represented by
_{R f - (CH 2) n} -Si- (NH) 1.5
(R _f : linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, n: natural number)
Fluoroalkylsilazane represented by
_{R f - (OC 3 F 6} ) n -O- (CF 2) m - (CH 2) L -OOCNH- (CH 2) s -Si (OR) 3
(R _f : linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, n: natural number, m: integer of 0 to 3, L: integer of 0 to 3, s: integer of 1 to 6, R Is an alkyl group)
Organopolysiloxanes, etc.
_{R f - (OC 3 F 6} ) n -O- (CF 2) m - (CH 2) L -O- (CH 2) s -Si (R) 3
(R _f : linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, n: natural number, m: integer of 0 to 3, L: integer of 0 to 3, s: integer of 0 to 6, R Is a hydrolyzable group)
And perfluoropolyether silane.

  Moreover, the mixture which consists of these combinations may be sufficient.

  The antifouling layer preferably has a contact angle with water of 100 ° or more and a contact angle with oleic acid of 70 ° or more. If it is less than this, water repellency and oil repellency may be insufficient, and antifouling performance may be insufficient.

  The method for forming the antifouling layer is not particularly limited, and either a gas phase method or a coating method may be used.

  As the vapor phase method, a CVD method or a vapor deposition method can be used.

  Examples of the coating method include a gravure coating method, a die coating method, a dip coating method, a spin coating method, a flow coating method, a spray coating method, and a roll coating method.

  The solvent used for coating is one selected from alcohols such as water, ethanol, propanol, butanol and isobutyl alcohol, fluorine-based solvents such as methyl nonafluoroisobutyl ether and methyl nonafluorobutyl ether, and methyl cellosolve. Combinations can be used. Moreover, phosphoric acid etc. can be added as a hydrolysis initiator.

  Further, ammonia or phosphoric acid may be added as a pH adjusting agent to adjust the pH.

  Moreover, you may give energy, such as drying, a heat | fever, ionizing radiation, and plasma, after application | coating as needed.

  The film thickness of the antifouling layer is preferably in the range of 3 to 50 nm, more preferably in the range of 5 to 15 nm. When it is 3 nm or less, the antifouling performance and alkali resistance are insufficient, and when it is 50 nm or more, the mechanical strength is poor.

  In addition, when the functional layer is an optical film such as an antireflection layer, the film thickness of the antifouling layer must be set so that the optical performance can be obtained as a whole in consideration of the optical film thickness of the optical film and the antifouling underlayer. There is.

  In the present invention, since the low refractive index layer, which is the lower layer of the antifouling layer, is dense, by providing the antifouling layer thereon, the resistance to alkali or the like is enhanced. Further, when the antifouling layer is provided on such a low refractive index layer, the antifouling layer itself is densely formed and the antifouling performance is improved.

  The weak alkali resistance between the low refractive index layer and the antifouling layer is, for example, when the low refractive index layer is silicon oxide and the antifouling layer is fluorocarbon silane, such as Si-O-Si bond between fluorocarbon silane and silicon oxide. When alkaline aqueous solution such as NaOH aqueous solution penetrates into the antifouling layer, Si—O—Si bonds are easily hydrolyzed and the antifouling layer is detached from silicon oxide. There is.

  For this reason, the conventional method of providing a low refractive index layer made of, for example, silicon oxide and simply introducing fluorine on the layer has sufficient water repellency and antifouling properties in an antireflection film such as a display surface or a spectacle lens surface. The alkali resistance cannot be imparted. That is, the penetration of the alkaline aqueous solution and the nasal oil component into the antifouling layer cannot be sufficiently prevented, and becomes prominent particularly when time passes.

  Thus, by providing a dense low-refractive index layer, the antifouling layer is formed densely so that alkali components and chlorine components cannot enter, and the antifouling layer can be prevented from being destroyed and the lower layer deteriorated. Therefore, antifouling performance can be maintained for a long time.

  As a measure of alkali resistance, a 1% NaOH aqueous solution of the antifouling layer is dropped and allowed to stand for 1 hour, and then the contact angle with respect to water after washing and drying the dripping portion is preferably 100 ° or more. Within this range, at the practical stage, the antifouling layer is not destroyed by the alkali component, and the antifouling performance can be maintained for a long time.

  In addition, when the dense low refractive index layer and the antifouling layer are provided by a CVD method, the dense low refractive index layer raw material gas and the antifouling layer raw material gas may be used to form a film. In this case, the dense low refractive index layer and the antifouling layer are formed at different rates depending on the conditions, and the dense low refractive index layer is formed first, and the antifouling layer can be formed thereon.

  The same applies when the coating method is used. By applying and drying a mixture of a coating liquid that is a raw material for the dense low refractive index layer and a coating liquid that is a raw material for the antifouling layer, the dense low refractive index layer and the anti-reflection layer are protected. A dirty layer may be provided. In this case, depending on conditions such as the hydrolysis reaction rate of the raw material, the film forming speed of the dense low refractive index layer and the antifouling layer is different, and the dense low refractive index layer is formed first, and the antifouling layer is formed thereon. A layer can be formed.

  In the present invention, a hard coat layer, an antistatic layer, an antiglare layer and the like can be further provided between the substrate and the antireflection layer.

  The hard coat layer used in the present invention can be provided by a known method using a known material.

  For example, examples of the material include ionizing radiation curable acrylic resin and silicon oxide, and examples of the forming method include a coating method.

  The ionizing radiation curable acrylic resin is composed of a polymer mainly composed of a polyfunctional monomer containing two or more (meth) acryloyloxy groups in one molecule. Examples of the polyfunctional monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, tri Ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, diethylene glycol bis β- (meth) acryloyloxypropionate, Trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, (2-hydroxyethyl) isocyanate di (meth) acrylate, pentaerythritol tetra (meth) acrylate, 2,3-bis (meth) acryloyloxyethyloxymethyl [2.2.1] heptane, poly 1,2-butadiene di (Meth) acrylate, 1,2-bis (meth) acryloyloxymethylhexane, nonaethylene glycol di (meth) acrylate, tetradecane ethylene glycol di (meth) acrylate, 10-decanediol (meth) acrylate, 3,8-bis (Meth) acryloyloxymethyltricyclo [5.2.10] decane, hydrogenated bisphenol A di (meth) acrylate, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 1,4- Bis ((meth) acryloyl Examples thereof include oxymethyl) cyclohexane, hydroxypivalate ester neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, and epoxy-modified bisphenol A di (meth) acrylate. In particular, acrylic resins such as acrylic acid esters, acrylamides, methacrylic acid esters, and methacrylamides that are ultraviolet curable, organic silicon resins, thermosetting polysiloxane resins, and the like are suitable. The said polyfunctional monomer may use only 1 type and may use 2 or more types together. If necessary, a monofunctional monomer may be copolymerized.

  The hard coat layer preferably has a refractive index equivalent or close to that of the base material in order to ensure the transparency of the antireflection member.

  If the thickness of the hard coat layer is in the range of 3 to 20 μm, sufficient mechanical strength is exhibited, but it is preferably in the range of 5 to 15 μm from the viewpoint of transparency, coating accuracy, and handleability.

  Moreover, a refractive index adjusting agent, an antistatic material, a concavo-convex forming material, or the like can be added to the hard coat layer.

  The hard coat layer is preferably subjected to a surface treatment. By performing the surface treatment, adhesion with other adjacent layers can be improved.

  Examples of the surface treatment of the hard coat layer include a high frequency discharge plasma method, an electron beam method, an ion beam method, a vapor deposition method, a sputtering method, an alkali treatment method, an acid treatment method, a corona treatment method, and an atmospheric pressure glow discharge plasma method. Can be mentioned. Among these, alkali treatment is preferable.

  Examples of the alkaline aqueous solution used in the alkali treatment method include aqueous solutions such as sodium hydroxide and potassium hydroxide, and alkaline aqueous solutions obtained by adding various organic solvents such as alcohol to these. As the conditions for the alkali treatment, for example, when an aqueous sodium hydroxide solution is used, it is preferably used as an aqueous solution having a concentration of 0.1 to 10N, preferably 1 to 2N. Moreover, the temperature of aqueous alkali solution is 0-100 degreeC, Preferably it is 20-80 degreeC. The alkali treatment time is 0.01 to 10 hours, preferably 0.1 to 1 hour. However, when such alkali cleaning is performed, it is necessary to perform sufficient cleaning so that no alkali component remains.

  Examples of the antistatic layer of the present invention include those in which an antistatic material is contained in a matrix made of an ionizing radiation curable resin or silicon oxide. As the ionizing radiation curable resin, the same ones as described above can be used. Silicon oxide can be formed by a sol-gel method using silicon alkoxide as a raw material.

  Further, an antistatic effect may be imparted by incorporating an antistatic material into the hard coat layer.

  Antistatic materials include antimony oxide and tin oxide compounds.

  Examples of the antiglare layer of the present invention include those obtained by adding an irregularity forming material to an ionizing radiation curable resin and those obtained by forming irregularities on the surface of an ionizing radiation curable resin. As the ionizing radiation curable resin, the same ones as described above can be used. Silicon oxide can be formed by a sol-gel method using silicon alkoxide as a raw material.

  As an uneven | corrugated material, the particle | grains which consist of metal oxides, such as resin with a particle size of 0.1-10 micrometers and silicon oxide, are mentioned.

  Further, these particles may be contained in the hard coat layer, or an antiglare effect may be provided by forming irregularities on the surface of the hard coat layer.

  The laminate obtained by the present invention can be used as a front plate of a display device such as a liquid crystal display device or a plasma display.

  Further, if a polarizing plate is used for the substrate, it can also be used as a polarizing plate.

  As the substrate, a hard coat layer made of an ionizing radiation curable acrylic resin having a thickness of 5 μm on a triacetyl cellulose (TAC) film having a thickness of 80 μm was formed by wet coating. Moreover, the refractive index n of this TAC film was 1.49.

Further, an antireflection layer was provided on the TAC film substrate on which the hard coat layer was formed. The antireflection layer was formed by a reactive sputtering method. The layer structure is TiO ₂ (refractive index 2.3, nd = 60 nm) as the first layer from the substrate side, SiO ₂ (refractive index 1.46, nd = 40 nm) as the second layer, and TiO 2 as the third layer. ₂ (refractive index 2.3, nd = 110 nm) and SiO ₂ (refractive index 1.46, nd = 145 nm) as the fourth layer. The fourth layer of SiO ₂ has a two-layer structure, the low refractive index layer on the substrate side has an optical film thickness nd = 45 nm, and the low refractive index layer on the antifouling layer side has an optical film thickness nd = 100 nm. The thickness nd was set to 145 nm.

The reactive sputtering method was used for each layer from the low refractive index layer consisting of two layers of the fourth layer to the low refractive index layer on the substrate side. As the target material, Ti was used for TiO _{2 and} Si was used for SiO ₂ . The introduced gas was mixed plasma of Ar gas and O ₂ gas, and the film formation pressure was 0.3 Pa and the distance between the substrate and the target was 100 mm.

  Next, a dense low refractive index layer and an antifouling layer on the antifouling layer side were sequentially formed using a plasma CVD method.

The degree of vacuum exhaust before film formation is 1 × 10 ⁻³ Pa, a parallel plate type electrode is used as a method for generating plasma, a cathode is a magnetron electrode for generating high-density plasma, and the distance between electrodes is 40 mm. It was. The plasma generation power supply was discharged using a high frequency power supply of 13.56 MHz, and the TAC substrate on which the antireflection layer was laminated was placed on the anode.

  The introduced gas uses organomethoxysilane (the following chemical formula (1)) as the raw material gas for the dense low refractive index layer on the antifouling layer side, and fluorocarbon silane manufactured by GE Toshiba Silicone Co., Ltd. as the raw material gas for the antifouling layer This was performed using TSL8233 (the following chemical formula (2)). In addition to these raw materials, a film was formed by introducing Ar gas.

(CH ₃ ) Si— (OCH ₃ ) ₃ (1)
_{C 8 F 17 -CH 2 CH 2} -Si (OCH 3) 3 (2)
When depositing the dense low refractive index layer and antifouling layer on the antifouling layer side, when introducing each gas into the vacuum chamber, the gas flow rate is controlled by a mass flow controller, and a constant flow rate is kept in the chamber. As introduced in In addition, the vacuum chamber is provided with a differential exhaust valve, and the atmospheric pressure in the chamber can be kept in an arbitrary constant state with respect to the gas flow rate.

  The antifouling layer is formed so that the fluorocarbon silane TSL8233 completely fills the adsorption sites on the surface of the dense low refractive index layer on the antifouling layer side, that is, the film thickness is about d = 5 to 10 nm. I did it. As a result, the performance as anti-reflection is suppressed to a value where the reflection Y value is lower than 0.4%, and the anti-reflection function is provided.

  At this time, the electric power applied between the electrodes was 50 W, and the discharge was performed with the pressure of the mixed gas of organomethoxysilane and Ar, and the mixed gas of TSL8233 and Ar gas set to 5 Pa, respectively.

  As an antifouling layer, the same procedure as in Example 1 was conducted except that OPTOOL DSX manufactured by Daikin Industries, Ltd. was formed by vacuum deposition.

  The same procedure as in Example 1 was performed up to the low refractive index layer on the substrate side of the low refractive index layer composed of the second layer of the fourth layer.

  Next, a fine low refractive index layer and an antifouling layer on the antifouling layer side were formed by sequentially coating using a microgravure method.

  The coating solution for the dense low refractive index layer is a mixed solution of water, isobutyl alcohol, methyl cellosolve, and organomethoxysilane (the above chemical formula (1)), and the coating solution for the antifouling layer is water, isobutyl alcohol, methyl. It is a mixed solution composed of cellosolve and fluorocarbon silane (the above chemical formula (2)), and phosphoric acid was used as a hydrolysis initiator for organomethoxysilane and fluorocarbon silane.

  After that, as the pH adjuster, ammonia, phosphoric acid, or both were added and adjusted.

  The coating solution for the dense low refractive index layer on the antifouling layer side is prepared as a chemical solution with a solid component = 4 wt% so that the optical film thickness of the dense low refractive index layer on the antifouling layer side is nd = 100 nm. The target coating thickness was set to 1.7 μm and cured by heating. The antifouling layer coating solution was prepared as a solid component = 0.1 wt% chemical solution, and the target coating film thickness was 7 μm, followed by heat treatment. As a result, an antireflection layer having a desired spectral curve can be formed on the TAC substrate.

  The same process as in Example 1 was performed up to the third high refractive index layer.

A dense low refractive index layer made of SiO ₂ (refractive index 1.46, nd = 145 nm) was provided thereon as a fourth low refractive index layer. As a film forming method, a plasma CVD method using organomethoxysilane represented by the above chemical formula (1) as a source gas was used. On top of that, an antifouling layer was provided using a plasma CVD method using the fluorocarbon silane represented by the chemical formula (2) as a raw material gas. The CVD conditions were the same as in Example 1.

  The same process as in Example 1 was performed up to the third high refractive index layer.

A dense low refractive index layer made of SiO ₂ (refractive index 1.46, nd = 145 nm) was provided thereon as a fourth low refractive index layer using a microgravure method. On top of that, an antifouling layer was provided using a micro gravure method.

  The coating solution for the dense low refractive index layer is a mixed solution of water, isobutyl alcohol, methyl cellosolve, and organomethoxysilane (the above chemical formula (1)), and the coating solution for the antifouling layer is water, isobutyl alcohol, methyl. It is a mixed solution composed of cellosolve and fluorocarbon silane (the above chemical formula (2)), and phosphoric acid is used as a hydrolysis initiator for organomethoxysilane and fluorocarbon silane.

  After that, as the pH adjuster, ammonia, phosphoric acid, or both were added and adjusted.

The coating solution for the dense low refractive index layer is prepared as a chemical solution with a solid component = 4 wt%, and is applied so that the optical film thickness of the dense low refractive index layer on the antifouling layer side is nd = 145 nm. Cured. The coating solution for the antifouling layer was prepared as a solid component = 0.1 wt% chemical solution, and the target coating film thickness was 7 μm, followed by heat treatment. As a result, an antireflection layer having a desired spectral curve can be formed on the TAC substrate.
<Comparative Example 1>
A hard coat layer is provided on the TAC substrate in the same manner as in Example 1, and TiO ₂ (refractive index 2.3, nd = 60 nm) is formed as the first layer thereon, and SiO ₂ (refractive index 1.46, as the second layer). (nd = 40 nm) An antireflection layer made of TiO ₂ (refractive index 2.3, nd = 110 nm) as the third layer and SiO ₂ (refractive index 1.46, nd = 145 nm) as the fourth layer is reactive sputtering. Fluorocarbon silane TSL8233 (the above chemical formula (2)) manufactured by GE Toshiba Silicone Co., Ltd. was formed using a vacuum deposition method.
<Comparative example 2>
As an antifouling layer, the same procedure as in Comparative Example 1 was performed except that OPTOOL DSX manufactured by Daikin Industries, Ltd. was provided by vacuum deposition.
<Evaluation>
The following tests (1) to (6) were performed on the obtained samples of Examples 1 to 5 and Comparative Examples 1 and 2, the performance was examined, and the results are shown in Table 1.
(1) Contact angle measurement with water (2) Contact angle measurement with oleic acid (3) Alkali resistance test (1% NaOH aqueous solution dropwise)
(4) Alkali resistance test (5% NaOH aqueous solution dropwise)
(5) Fingerprint wiping test (6) Oil-based ink wiping test The contact angles of (1) to (4) were measured by “Contact Angle Meter CA-X” manufactured by Kyowa Interface Chemical Co., Ltd. In the alkali resistance tests (3) and (4), a 1 and 5% NaOH aqueous solution was dropped on the film and allowed to stand for 1 hour, then the dripping part was washed away with pure water, dried, and then contacted with pure water. Measurements were made and evaluated.

  In the fingerprint wiping test of (5), an actual nasal oil was used, and the fingerprint of the nasal oil attached on the substrate was wiped off with a clean cloth, and the result was subjected to visual sensory evaluation.

  In the oil-based ink wiping test of (6), a 20 mm line was drawn using “Teranishi Chemical Co., Ltd. oil-based ink ink / for fine writing”, the drawn line was wiped with a clean waste cloth, and the result was visually observed. The sensory evaluation of was performed.

The criteria for sensory evaluation of tests (5) and (6) are shown below in three stages: ○, Δ, and ×.
○: Fingerprints can be completely wiped Δ: Fingerprint wipe traces remain ×: Fingerprint wipe traces spread and cannot be wiped off

上記表１の結果より、本発明による実施例１〜５は、比較例１、２に対し、耐アルカリ性、耐熱性において明らかに優れていることが分かる。比較例１、２が耐アルカリ性において撥水効果を失うのに対し、本実施例は撥水効果を保ったままであることが分かる。また、指紋拭き取り性試験、油性インキ拭き取り性試験においても比較例１と比べても明らかに良いことが分かった。また、実施例１で用いたＴＳＬ８２３３とより分子量も大きく防汚性能が高く高価である比較例２で用いたダイキン工業社製オプツールＤＳＸと同等の防汚性能が得られることが分かった。すなわち実施例１、３では、防汚剤の種類によらず、高い防汚性能が得られることが分かった。

From the results of Table 1 above, it can be seen that Examples 1 to 5 according to the present invention are clearly superior to Comparative Examples 1 and 2 in alkali resistance and heat resistance. It can be seen that Comparative Examples 1 and 2 lose the water repellent effect in alkali resistance, while the present example still maintains the water repellent effect. It was also found that the fingerprint wiping test and the oil-based ink wiping test were clearly better than Comparative Example 1. Further, it was found that the same antifouling performance as that of Opkin DSX manufactured by Daikin Industries Co., Ltd. used in Comparative Example 2, which is higher in molecular weight and higher in antifouling performance and expensive than TSL8233 used in Example 1, was obtained. That is, in Examples 1 and 3, it was found that high antifouling performance was obtained regardless of the type of antifouling agent.

The following tests (7) to (9) were performed on the examples and comparative examples of the present invention, and the results are shown in the following Tables 2 to 4, respectively, showing the effect of the present invention on the time axis.
(7) Contact angle measurement after dropping 1% NaOH aqueous solution 15 minutes, 30 minutes, 60 minutes, and 120 minutes (H ₂ O)
(8) Contact angle measurement 15 minutes, 30 minutes, 60 minutes, and 120 minutes after dropping 5% NaOH aqueous solution (H ₂ O)
(9) Contact angle measurement (H ₂ O) after 15 minutes, 30 minutes, 60 minutes, and 120 minutes after dropping a 10% NaOH aqueous solution

表２〜表４の結果より、実施例１〜５が時間軸に対して、明らかに比較例１、２に比べて良いことが分かる。

From the results of Tables 2 to 4, it can be seen that Examples 1 to 5 are clearly better than Comparative Examples 1 and 2 with respect to the time axis.

It is sectional drawing which shows one Example of the reflection preventing member of this invention. It is sectional drawing which shows one Example of the reflection preventing member of this invention. It is sectional drawing which shows one Example of the reflection preventing member of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Hard-coat layer 3 Low-refractive-index layer 3a Dense low-refractive-index layer 3b Normal low-refractive-index layer 4 High-refractive-index layer 5 Antifouling layer

Claims (8)

  An antireflective member comprising an antireflective layer comprising a low refractive index layer and an antifouling layer on a substrate, wherein the antifouling layer has a contact angle with water of 100 ° or more, and is in contact with oleic acid An antireflection member having an angle of 70 ° or more.   2. The contact angle to water after the 1% NaOH aqueous solution of the antifouling layer is dropped and left for 1 hour, and then the dripping portion is washed and dried, is 100 ° or more. Antireflection member.   The antireflection member according to claim 1, wherein the low refractive index layer is composed of two layers.   The antireflective member according to claim 3, wherein, of the two low refractive index layers, the low refractive index layer on the antifouling layer side is denser than the low refractive index on the substrate side.   The antireflection member according to claim 1, wherein the antireflection layer includes a high refractive index layer and / or a medium refractive index layer.   The antireflection member according to any one of claims 1 to 5, further comprising at least one layer selected from a hard coat layer, an antistatic layer, and an antiglare layer between the substrate and the antireflection layer. .   A polarizing plate comprising the antireflection member according to claim 1.   A display device comprising the antireflection member according to claim 1 or the polarizing plate according to claim 7.

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