JP2007148201A - Method for manufacturing antireflection film and display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an antireflection film which has low reflectivity and high transmissivity, is excellent in durability and an antistatic characteristic, and suppresses generation of discharge, with high productivity and at a low cost, and also to provide a display apparatus. <P>SOLUTION: The method for manufacturing the antireflection film 1 has processes of: forming a 1st oxide layer 21 which consists essentially of tin oxide and silicon dioxide and in which a ratio of tin to silicon is within a specific range on a base material 10; forming a 2nd oxide layer 22 which consists essentially of gallium oxide, indium oxide and tin oxide and in which a ratio between gallium, indium and tin is within a specific range or a 2nd oxide layer 22 which consists essentially of tin oxide on the 1st oxide layer 21; and forming a 3rd oxide layer 23 consisting essentially of silicon dioxide by a wet coating method on the 2nd oxide layer 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing an antireflection film, and a display device including the antireflection film obtained by the production method.

  Conventionally, an antireflection film has been provided on a display screen in order to improve the visibility of a display device. As this antireflection film, for example, a film in which an antireflection layer comprising a medium refractive index layer, a high refractive index layer, and a low refractive index layer in order from the base material side is provided on a base material is known and visible. Designed to reduce reflection over the entire light region. In addition, the antireflection film has low reflectivity over the entire visible light region, high transmittance, excellent durability such as scratch resistance and water resistance, and antistatic properties to prevent dust and the like from adhering. It is required to have.

As an antireflection film, a medium refractive index layer made of an oxide of an alloy of tin and silicon, a high refractive index layer made of a mixture of indium oxide and tin oxide (hereinafter referred to as ITO) on a base material, Patent Document 1 discloses a film provided with an antireflection layer made of a low refractive index layer made of silicon dioxide.
Since the antireflection film described in Patent Document 1 has a layer made of ITO having excellent conductivity, it has excellent antistatic properties that suppress adhesion of dust and the like. However, an antireflection film having a layer made of ITO has a surface resistance value that is too low, so that when a charged object approaches the antireflection film, a discharge easily occurs between the charged object and the antireflection film. Have. Furthermore, when an antireflection film is bonded to a dielectric material such as glass having a low resistance layer such as a metal film for shielding electromagnetic waves on the back surface to make a display front filter, the overall capacitance of the filter increases. For this reason, there is a problem that the film surface is easily charged due to the influence of the electromagnetic wave emitted from the display, and discharge is easily generated between the approaching object and the antireflection film.

Further, when a low refractive index layer made of silicon dioxide is formed by a sputtering method, it takes time to form the low refractive index layer, and there is a problem that equipment cost and running cost are increased.
JP 2003-94548 A

  The object of the present invention is to obtain an antireflection film with low productivity and low cost over the entire visible light region, with high transmittance, excellent durability and antistatic properties, and capable of suppressing the occurrence of discharge. Another object of the present invention is to provide a manufacturing method capable of producing a display device, and a display device having high visibility of displayed images, antistatic properties, and hardly causing discharge.

  The method for producing an antireflection film of the present invention comprises, on a base material, tin oxide and silicon dioxide as main components, and the proportion of silicon is 20 to 50 atomic percent of the total of tin and silicon (100 atomic percent). A step of forming a certain first oxide layer, and a main component of gallium oxide, indium oxide, and tin oxide on the first oxide layer, and the ratio of gallium is the sum of gallium, indium, and tin (100 2) to 15 atomic% of the second oxide layer, or the ratio of indium is 2 to 15 atomic% of the total (100 atomic%) of gallium, indium, and tin, or oxidation Forming a second oxide layer mainly composed of tin, and forming a third oxide layer mainly composed of silicon dioxide on the second oxide layer by a wet coating method. It is characterized by having.

In the method for producing an antireflection film of the present invention, a coating liquid containing at least one selected from the group consisting of silazane, an oligomer of silazane, an alkoxysilane, and an oligomer of alkoxysilane is formed on the second oxide layer. It is preferable to form a third oxide layer by coating.
The display device of the present invention comprises a display screen for displaying an image, and an antireflection film provided on the viewing side of the display screen and obtained by the production method of the antireflection film of the present invention. Features.
The surface resistance value of the antireflection film is preferably 10 ⁴ to 10 ¹¹ Ω / □.

According to the method for producing an antireflection film of the present invention, an antireflection film having low reflectance and high transmittance over the entire visible light region, excellent durability and antistatic properties, and capable of suppressing the occurrence of discharge is productive. Well, it can be obtained at low cost.
The display device of the present invention has high visibility of displayed images, has antistatic properties, and does not easily cause discharge.

<Antireflection film>
FIG. 1 is a schematic cross-sectional view showing an example of an antireflection film obtained by the production method of the present invention. The antireflection film 1 includes a base material 10, a transparent antireflection layer 20 provided on the base material 10, and an antifouling layer 30 provided on the antireflection layer 20. .

(Base material)
The substrate 10 may be a plastic film that is smooth and can transmit light having a wavelength in the visible light region.
Examples of the plastic include polyethylene terephthalate, polycarbonate, triacetyl cellulose, polyether sulfone, and polymethyl methacrylate.
The thickness of the base material 10 is suitably selected according to a use, and 50-200 micrometers is preferable. The base material 10 may be composed of a single layer or may be a laminate composed of a plurality of layers.

(Antireflection layer)
The antireflection layer 20 includes a first oxide layer 21, a second oxide layer 22, and a third oxide layer 23 from the substrate 10 side.

  The first oxide layer 21 is a layer mainly composed of tin oxide and silicon dioxide. When the first oxide layer 21 is mainly composed of tin oxide and silicon dioxide, in the antireflection film 1, the adhesion at the interface between the substrate 10 and the first oxide layer 21 becomes good, Scratch resistance and water resistance are improved.

The first oxide layer 21 layer preferably contains 90% by mass or more of SnO ₂ and SiO ₂ in total in the first oxide layer 21 (100% by mass) in terms of oxide, and 95% by mass. % Or more is more preferable, and 99% by mass or more is particularly preferable.

In the first oxide layer 21, it is considered that tin and silicon exist in a mixed form of SnO ₂ , SiO ₂ , and composite oxides thereof. Therefore, the oxide content in the first oxide layer 21 is the oxide equivalent (SnO ₂ and SiO ₂ ) content obtained by measurement by ESCA (X-ray photoelectron spectroscopy) or Rutherford backscattering method. It shall be expressed as ESCA is measured by using an apparatus name: ESCA5500, manufactured by ULVAC-PHI, under the conditions of X-ray source: monochromated Al, X-ray: Kα ray, with the detector at an angle of 45 ° with respect to the sample surface.

  In the 1st oxide layer 21, other metals other than tin and silicon may be suitably contained as needed as long as the physical properties are not impaired. For example, gallium, indium, aluminum, magnesium and the like may be included.

  The ratio of silicon in the first oxide layer 21 is 20 to 50 atomic% in the total of tin and silicon (100 atomic%), and preferably 25 to 45 atomic%. By setting the ratio of silicon in the first oxide layer 21 within this range, the first oxide layer 21 has an appropriate refractive index, and is good in visible light transmittance, visible light reflectance, and the like. An antireflection film 1 having excellent optical characteristics is obtained.

  The physical film thickness (hereinafter simply referred to as “film thickness”) of the first oxide layer 21 is preferably 45 to 65 nm, and particularly preferably 50 to 60 nm. The “film thickness” in the present invention is a film thickness measured by a stylus type surface roughness measuring machine.

  The refractive index (n) of the first oxide layer 21 is preferably 1.74 to 1.88. The “refractive index (n)” in the present invention is a refractive index in light having a wavelength of 550 nm.

The second oxide layer 22 is a layer mainly composed of gallium oxide, indium oxide and tin oxide (hereinafter referred to as GIT layer) or a layer mainly composed of tin oxide (hereinafter referred to as SnO ₂ layer). It is written.) The second oxide layer 22 is mainly composed of gallium oxide, indium oxide and tin oxide, or the tin oxide is the main component, so that the surface resistance value of the antireflection film 1 is within an appropriate range. It has an antistatic property and can suppress the discharge phenomenon.

The GIT layer preferably contains 95% by mass or more of Ga ₂ O ₃ , In ₂ O ₃ and SnO ₂ in total in the second oxide layer 22 (100% by mass) in terms of oxide, and 99% by mass. It is more preferable to contain at least%.

In the GIT layer, gallium, indium and tin are considered to exist in a mixed form of Ga ₂ O ₃ , In ₂ O ₃ , SnO ₂ , and complex oxides thereof. Therefore, the oxide content in the GIT layer is expressed as an oxide equivalent (Ga ₂ O ₃ , In ₂ O ₃ , and SnO ₂ ) content obtained by measurement by ESCA or Rutherford backscattering method. To do.

  In the GIT layer, other metals other than gallium, indium, and tin may be appropriately included as oxides as needed as long as the physical properties are not impaired. For example, aluminum, magnesium, silicon and the like may be included.

  The ratio of gallium in the GIT layer is 2 to 15 atomic% in the total (100 atomic%) of gallium, indium and tin. Further, the ratio of indium in the GIT layer is 2 to 15 atomic% in the total (100 atomic%) of gallium, indium and tin. By making the ratio of gallium and indium in the GIT layer within this range, the balance between the antistatic property and the discharge suppression in the antireflection film 1 becomes good.

Since the SnO ₂ layer contains tin oxide as a main component, the balance between the antistatic property and the discharge suppression in the antireflection film 1 becomes good. The SnO ₂ layer preferably contains 90% by mass or more, more preferably 95% by mass or more, and 99% by mass or more of SnO ₂ in the second oxide layer 22 (100% by mass). It is particularly preferred. The oxide content in the SnO ₂ layer is expressed as an oxide equivalent (SnO ₂ ) content obtained by measurement by ESCA or Rutherford backscattering method.

In the SnO ₂ layer, other metals other than tin may be appropriately contained as necessary as long as the physical properties are not impaired. For example, gallium, indium, aluminum, magnesium, silicon and the like may be included.

The film thickness of the second oxide layer 22 is preferably 90 to 110 nm, and particularly preferably 95 to 100 nm.
The refractive index (n) of the second oxide layer 22 is preferably 1.9 to 2.1. By setting the refractive index (n) of the second oxide layer 22 within this range, the optical characteristics can be kept within a desired range in terms of visible light transmittance, visible light reflectance, and the like.

The third oxide layer 23 is a layer mainly composed of silicon dioxide. When the third oxide layer 23 contains silicon dioxide as a main component, the third oxide layer 23 has an appropriate refractive index, and the resulting antireflection film 1 has a visible light transmittance, visible light. Optical characteristics such as light reflectance can be kept within a desired range.
The third oxide layer 23 is particularly preferably a layer made of silicon dioxide.

In the third oxide layer 23, other metals other than silicon may be appropriately contained as necessary as long as the physical properties are not impaired. For example, gallium, indium, aluminum, magnesium, tin and the like may be included.
The third oxide layer 23 may contain a binder, fine particles, an antifouling agent, an antifoaming agent, a leveling agent and the like as long as the physical properties are not impaired.

The thickness of the third oxide layer 23 is preferably 70 to 150 nm, and particularly preferably 85 to 125 nm.
The refractive index (n) of the third oxide layer 23 is preferably 1.50 or less, and particularly preferably 1.48 or less.
By configuring each oxide layer with a predetermined optical film thickness (refractive index × physical film thickness), the antireflection film 1 having desired optical characteristics (transmittance, reflectance) can be obtained. .

(Other layers)
The antireflection film of the present invention may have an antifouling layer on the antireflection layer 20 in order to protect the antireflection layer 20 and enhance the antifouling performance. By providing the antifouling layer, the function of the antireflection layer 20 is not hindered and can be easily wiped off when the outermost surface is soiled with fingerprints or the like.
As the antifouling layer, an oil-repellent film containing perfluorosilane, fluorocarbon or the like is preferable.
The film thickness of the antifouling layer is preferably 20 nm or less, and more preferably 10 nm or less.

The antireflection film of the present invention may have a hard coat layer between the substrate 10 and the antireflection layer 20 in order to impart desired hardness to the antireflection film 1.
As the hard coat layer, a material having transparency and being equal to the refractive index (n) of the substrate 10 or having a refractive index within ± 0.1 with respect to the refractive index (n) of the substrate 10 is preferable. . Examples of the material of the hard coat layer include an acrylic resin, a silicone resin, or a material in which an additive is added thereto.
The film thickness of the hard coat layer is preferably 10 μm or less.

The antireflection film of the present invention is oxidized in order to prevent oxidation at the time of film formation and improve adhesion between the base material 10 and the first oxide layer 21 and all or part of each oxide layer. You may have a barrier layer.
The oxidation barrier layer is a thin film formed to prevent oxidation of another layer formed thereunder, and has no optical meaning. Examples of the oxidation barrier layer include various metals or metal nitrides such as silicon nitride.
The film thickness of the oxidation barrier layer is preferably 5 nm or less.

<Method for producing antireflection film>
The method of manufacturing the antireflection film 1 includes a step of forming the first oxide layer 21 on the substrate 10, a step of forming the second oxide layer 22 on the first oxide layer 21, And forming a third oxide layer 23 on the second oxide layer 22 by a wet coating method.

  As a method for forming the first oxide layer 21 and the second oxide layer 22, physical vapor deposition methods such as vacuum deposition method, reactive deposition method, ion beam assisted deposition method, sputtering method and ion plate method; Examples include chemical vapor deposition such as plasma CVD. A sputtering method is particularly preferred because it is easy to obtain a uniform film thickness over a large area.

In the present invention, a coating solution containing at least one silicon dioxide raw material selected from the group consisting of silazane, an oligomer of silazane, an alkoxysilane, and an oligomer of alkoxysilane is coated on the second oxide layer. Thus, a third oxide layer is formed.
Specifically, the third oxide layer is formed by applying a coating solution obtained by dissolving or dispersing a silicon dioxide raw material in a solvent onto the second oxide layer 22 by a wet coating method. It is formed by drying.

  Examples of the alkoxysilane include tetramethoxysilane, tetraethoxysilane (hereinafter referred to as TEOS), tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, and the like. It is done.

Examples of the solvent include alcohols such as methanol, ethanol, isopropanol and n-butanol; ketones such as methyl ethyl ketone; ethers such as diethyl ether and dibutyl ether; toluene, xylene and water. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
When the silicon dioxide raw material is silazane or an oligomer thereof, xylene and dibutyl ether are particularly preferable as the solvent.
When the silicon dioxide raw material is alkoxysilane or an oligomer thereof, the solvent is particularly preferably a mixed solvent of water and alcohol.

  The coating liquid preferably contains an acid catalyst such as hydrochloric acid, nitric acid, sulfuric acid, and acetic acid; and an alkali catalyst such as sodium hydroxide and ammonia as necessary.

You may add additives, such as a binder, microparticles | fine-particles, antifouling agent, an antifoamer, a leveling agent, to a coating liquid as needed.
Examples of the binder include ultraviolet or thermosetting resins such as acrylic resins and epoxy resins, and these are preferably contained in the coating liquid in a monomer or oligomer state. A binder may be used individually by 1 type and may use 2 or more types together. The content of the binder, relative to the SiO ₂ in terms of 100 parts by weight of the raw material of silicon dioxide, preferably 10 to 80 parts by weight.

The fine particles impart strength to the antireflection layer 20. Examples of the fine particles include inorganic fine particles and resin fine particles.
The amount of inorganic fine particles or resin fine particles added is preferably 10 to 80 parts by mass with respect to 100 parts by mass in terms of SiO _{2 of the} silicon dioxide raw material. When the addition amount of the inorganic fine particles or the resin fine particles is within this range, the antireflection effect of the obtained antireflection film is sufficient.

Examples of the inorganic fine particles include fine particles of metal oxides such as silica, tin oxide, alumina, titania, zirconia, ceria, yttria, and magnesia. One kind of inorganic fine particles may be used alone, or two or more kinds may be used in combination. The average particle size of the inorganic fine particles is preferably 0.01 to 0.5 μm.
As the inorganic fine particles, silica is preferable because the third oxide layer 23 is a layer mainly composed of silicon dioxide. Silica is preferably hollow silica or porous silica in that the refractive index of the resulting coating film can be lowered.

  Examples of the resin fine particles include polyester, polyurethane; fluorine resin such as tetrafluoroethylene resin and polyvinyl fluoride; and fine particles of resin such as melamine resin, silicone resin, polyvinyl chloride, and polyvinyl acetate. The resin fine particles may be used alone or in combination of two or more. The average particle diameter of the organic fine particles is preferably 0.01 to 0.5 μm. The resin fine particles are preferably used in the form of an emulsion dispersed in a solvent such as water.

Examples of the antifouling agent include fluorine-containing alkoxysilane and dimethyl silicone.
Examples of the fluorine-containing alkoxysilane include fluorotriethoxysilane, trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane and the like. An antifouling agent may be used individually by 1 type, and may use 2 or more types together.

The addition amount of the antifouling agent is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass in terms of SiO _{2 of the} silicon dioxide raw material. If the addition amount of the antifouling agent is within this range, the contact angle between the surface of the third oxide layer 23 and water is 70 degrees or more, so that the antireflection film can be imparted with antifouling properties, and the antifouling layer Is no longer necessary.

Wet coating methods include dip coating, comma coating, lip coating, flow coating, spraying, bar coating, gravure coating, roll coating, blade coating, air knife coating, spin coating, Examples thereof include a slit coating method, a micro gravure coating method, and a die coating method. The gravure coating method, the roll coating method, the micro gravure coating method, and the die coating method are preferable in that a thin film can be uniformly and rapidly formed.
What is necessary is just to set the drying conditions of a coating film suitably according to the solid content concentration of a coating liquid, the kind of solvent, etc. The drying temperature is usually 80 to 200 ° C., and the drying time is usually 1 to 10 minutes.

An antifouling layer may be formed on the antireflection layer 20. Examples of the method for forming the antifouling layer include a vapor deposition method, a sputtering method, and a wet coating method as appropriate.
A hard coat layer may be formed between the substrate 10 and the antireflection layer 20. Examples of the method for forming the hard coat layer include a wet coating method.
An oxidation barrier layer may be formed between the base material 10 and the first oxide layer 21 or all or part of each oxide layer. Examples of the method for forming the oxidation barrier layer include vapor deposition, sputtering, and CVD.

The surface resistance value of the antireflection film 1 obtained by the present invention is preferably 10 ⁴ to 10 ¹¹ Ω / □. By setting the surface resistance value of the antireflection film 1 to 10 ⁴ Ω / □ or more, the occurrence of discharge can be sufficiently suppressed. By setting the surface resistance value of the antireflection film 1 to 10 ¹¹ Ω / □ or less, the antistatic property is improved.

  In the manufacturing method of the antireflection film of the present invention described above, since the third oxide layer is formed by the wet coating method, the film forming speed is higher than the conventional sputtering method, and the equipment cost is increased. The running cost is low. Therefore, an antireflection film can be obtained with high productivity and low cost.

  Moreover, the antireflection film obtained by the production method of the present invention includes, in order from the base material, the first oxide layer, the second oxide layer, and the third oxide layer. The layer is mainly composed of tin oxide and silicon dioxide, and the proportion of silicon is 20 to 50 atomic percent of the total of tin and silicon (100 atomic percent), and the second oxide layer is The main component is gallium oxide, indium oxide and tin oxide, and the ratio of gallium is 2 to 15 atomic% of the total (100 atomic%) of gallium, indium and tin, and the ratio of indium is gallium and indium. It is a layer that is 2 to 15 atomic percent of the total (100 atomic percent) with tin, or a layer that contains tin oxide as a main component, and the third oxide layer is a layer that contains silicon dioxide as a main component. Because of the reflection over the entire visible light range High transmittance is low, durability, excellent antistatic properties, and the occurrence of discharge can be suppressed.

<Display device>
The display device of the present invention includes a display screen for displaying an image and an antireflection film provided on the viewing side of the display screen.

Examples of such a display device include a plasma display panel (PDP), a liquid crystal display device (LCD), an electroluminescence display (ELD), a cathode tube display device (CRT), and a field emission display (FED).
Accordingly, examples of the display screen for displaying an image include a PDP screen, an LCD screen, an ELD screen, a CRT screen, and an FED screen.

  The viewing side of the display screen is usually composed of a transparent substrate such as a glass substrate or a plastic substrate. In the display device of the present invention, the antireflection film of the present invention may be directly attached to the viewing side surface of the display screen using an adhesive or the like, or a gap is provided between the display screen and the display screen. An antireflection film may be installed.

  Further, a front plate made of glass, plastic or the like may be newly installed on the viewing side of the display screen, and the antireflection film of the present invention may be directly attached to the viewing side or display side of the front plate. Moreover, you may install the antireflection film of this invention in the visual recognition side or display side of a front board, leaving a clearance gap between front boards.

  In the display device of the present invention described above, the antireflection film obtained by the display screen for displaying an image and the antireflection film of the present invention provided on the viewing side of the display screen. Therefore, the displayed image has high visibility, has antistatic properties, and does not easily cause discharge.

[Example 1]
First, the surface of the polyethylene terephthalate (PET) film having a thickness of 100 μm, which is the base material 10, was cleaned by dry cleaning using an ion beam. In dry cleaning using an ion beam, a mixed gas of argon gas 100 sccm and oxygen gas 50 sccm is introduced into the sputtering apparatus, and argon ions and oxygen ions ionized by an ion beam source to which 40 W of power is applied are applied to the surface of the substrate 10. The irradiation was performed.

While introducing argon gas at 115 sccm and oxygen gas at 85 sccm, using a tin-silicon alloy target [tin: silicon = 60: 40 (atomic ratio)], pressure 0.55 Pa, frequency 100 kHz, power density 3.9 W / cm ² , DC pulse sputtering was performed under conditions of a reversal pulse width of 2.5 μs, and a first oxide layer 21 having a thickness of 55 nm and a refractive index (n) of 1.81 was formed on the surface of the substrate 10. When measured by Rutherford backscattering method, in the first oxide layer 21, silicon was 34 atomic% in the total of tin and silicon (100 atomic%). Further, in the first oxide layer 21, of all the total atoms (100 atomic%), tin is 19.9 atomic%, silicon is 10.1 atomic%, oxygen is 69.7 atomic%, and argon is 0.8. It was 3 atomic%. When this was converted into an oxide of SnO ₂ and SiO ₂ , it was 95.6% by mass.

While introducing argon gas at 90 sccm and oxygen gas at 110 sccm, using a tin target, DC pulse sputtering was performed under the conditions of pressure 0.62 Pa, frequency 100 kHz, power density 3.2 W / cm ² , and inversion pulse width 2.5 μsec. Then, a second oxide layer 22 having a thickness of 96 nm and a refractive index (n) of 2.0 was formed on the surface of the first oxide layer 21. When measured with ESCA 5500 manufactured by ULVAC-PHI, tin was 31.9 atomic% and oxygen was 68.1 atomic% in the total atomic total (100 atomic%) in the second oxide layer 22. When this was converted into SnO ₂ oxide, it was 98.6% by mass.

A dibutyl ether solution of silazane (manufactured by Clariant Japan, L120, solid content concentration 20% by mass) was diluted with dibutyl ether to prepare a silazane diluted solution (solid content concentration 3% by mass). A coating liquid was prepared by mixing 1000 g of a silazane diluted solution and 0.18 g of dimethyl silicone (manufactured by Azomax, DMS-S15) as an antifouling agent. The coating liquid is applied to the surface of the second oxide layer 22 using a bar coater, the coating film is dried at 90 ° C. for 2 minutes to distill off the solvent, and then the environment is 23 ° C. and the relative humidity is 55%. By leaving it under for 1 day, a third oxide layer having a thickness of 100 nm and a refractive index (n) of 1.43 was formed, and the antireflection film 1 of Example 1 was obtained.
The antireflection film 1 of Example 1 was evaluated as follows. The results are shown in Table 1.

(Visibility transmittance)
The transmittance was measured with a color analyzer (TC-1800, manufactured by Tokyo Denshoku Co., Ltd.), and the luminous transmittance (transmission stimulus value Y defined in JIS Z 8701) was determined from the transmittance.

(Luminous reflectance)
The reflectance was measured with a spectrophotometer (manufactured by Shimadzu Corporation, UV3150PC), and the luminous reflectance (stimulation value Y of reflection defined in JIS Z 8701) was determined from the reflectance. In order to cancel the back surface reflection of the film, the surface of the substrate 10 opposite to the antireflection layer 20 was painted black.

(Abrasion resistance)
A cloth soaked with ethanol is applied to the surface of the antireflection layer 20, and the appearance after 50 reciprocations in 4 minutes is visually observed while applying a pressure of 5 × 10 ⁴ Pa in the vertical direction. The scratch resistance was examined. The case where there was no change in appearance between before and after the test was marked with ◯, and the case where it changed was marked with ×.

(water resistant)
It was immersed in warm water at 60 ° C. for 24 hours, and the water resistance was examined by visually observing the appearance after 24 hours. The case where the immersion portion was not discolored before and after the immersion was marked with ◯, and the case where the color was changed was marked with ×.

(Discharge suppression)
A pinhole tester (type H, manufactured by Nikka Densaku Co., Ltd.) having a voltage of 3 kV applied to the tip of the probe is brought closer to the film at a speed of 0.5 m / second from the far side of the antireflection film 1 side of the antireflection film 1. It was judged visually whether or not the film was damaged by the discharge until the probe tip contacted, and the discharge suppression property was examined. The case where the film was not damaged was marked with ◯, and the case where it was received was marked with x.

(Surface resistance value)
It measured with the digital super high resistance / microammeter made from Advantest Corporation which has the electrode based on JISK6911. A non-contact measurement method was adopted for those having a low resistance value, and measurement was performed using a Sheet Resistivity Meter SRM-12 manufactured by NAYY.

[Example 2]
The substrate 10 was washed in the same manner as in Example 1 to form the first oxide layer 21 having a thickness of 55 nm on the surface of the substrate 10.

While introducing argon gas at 180 sccm and oxygen gas at 20 sccm, using a GIT target [gallium oxide: indium oxide: tin oxide = 4: 5: 91 mass%], pressure 0.88 Pa, frequency 100 kHz, power density 3.0 W DC pulse sputtering is performed under the conditions of / cm ² and inversion pulse width of 2.5 μs, and the second oxide layer 22 having a thickness of 96 nm and a refractive index (n) of 2.0 is formed on the surface of the first oxide layer 21. Formed. When measured with ESCA5500 manufactured by ULVAC-PHI, in the second oxide layer 22, gallium is 3.7 atomic% and indium is 5.4 atoms out of the total (100 atomic%) of gallium, indium and tin. % And tin were 90.9 atomic%. In the second oxide layer 22, gallium is 1.21 atomic%, indium is 1.75 atomic%, tin is 29.72 atomic%, and oxygen is 67.% of the total atomic total (100 atomic%). It was 32 atomic%. When this was converted into an oxide of Ga ₂ O ₃ , In ₂ O ₃ and SnO ₂ , it was 98.9% by mass.

1 g of 2% nitric acid and 454 g of ethanol were added to 100 g of an ethanol solution of TEOS (SiO ₂ concentration: 28 mass%, manufactured by GE Toshiba Silicone) and 5 g of water to hydrolyze, and a dispersion containing silica oligomer (SiO ₂ concentration of 5 % By weight) was prepared. To 500 g of the dispersion containing the silica oligomer, 2625 g of a mixed solvent of ethanol / butanol / diacetone alcohol / isopropyl alcohol (mass mixing ratio 2: 1: 1: 5) is added, and a diluent (SiO ₂ concentration 0.8 mass%) is added. ) Was prepared. A coating solution was prepared by mixing 500 g of the diluent and 0.15 g of tridecafluorooctyltrimethoxysilane (TSL8257, manufactured by GE Toshiba Silicone) as an antifouling agent. A third oxide layer having a thickness of 100 nm and a refractive index (n) of 1.45 was formed in the same manner as in Example 1 except that the coating solution was used, and the antireflection film 1 of Example 2 was obtained. It was.
The antireflection film 1 of Example 2 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 3
The substrate 10 was washed in the same manner as in Example 1 to form the first oxide layer 21 having a thickness of 55 nm on the surface of the substrate 10.
A second oxide layer 22 having a thickness of 96 nm was formed on the surface of the first oxide layer 21 in the same manner as in Example 2.

Mixed solution of alkoxysilane oligomer and hollow silica (Catalysts & Chemicals Industries Co., Ltd., ELCOM P-5005, solid content concentration of 2 mass%, the content 40 parts by mass of hollow silica to SiO ₂ in terms of 100 parts by weight of the oligomer of the alkoxysilane ) Is applied to the surface of the second oxide layer 22 using a bar coater, the coating film is dried at 140 ° C. for 2 minutes, and the solvent is distilled off to obtain a thickness of 100 nm and a refractive index (n) of 1 .39) of the third oxide layer was formed, and the antireflection film 1 of Example 3 was obtained.
The antireflection film 1 of Example 3 was evaluated as follows. The results are shown in Table 1.

[Comparative Example 1]
The substrate 10 was washed in the same manner as in Example 1.
While introducing a mixed gas in which 98% by volume of argon gas and 2% by volume of oxygen gas were introduced, an ITO target [indium oxide: tin oxide = 90: 10 (mass ratio)] was used, pressure 0.35 Pa, frequency 100 kHz, DC pulse sputtering was performed under the conditions of a power density of 1.5 W / cm ² and an inversion pulse width of 1.0 μs to form an ITO layer having a thickness of 20 nm and a refractive index (n) of 2.06 on the surface of the base material 10.

While introducing a mixed gas obtained by mixing 60% by volume of argon gas and 40% by volume of oxygen gas, using a SiC target [manufactured by Asahi Glass Ceramics Co., Ltd., silicon carbide, trade name: SC], pressure 0.35 Pa, frequency 100 kHz, power DC pulse sputtering was performed under the conditions of a density of 3.5 W / cm ² and an inversion pulse width of 4.5 μs to form a first SiO ₂ layer having a thickness of 30 nm and a refractive index (n) of 1.46 on the surface of the ITO layer. .

Using an AZO target [zinc oxide doped with 5% by mass of aluminum oxide] while introducing a mixed gas in which 95% by volume of argon gas and 5% by volume of oxygen gas were introduced, pressure 0.35 Pa, frequency 100 kHz, power DC pulse sputtering was performed under the conditions of a density of 3.7 W / cm ² and an inversion pulse width of 1.0 μs to form an AZO layer having a thickness of 125 nm and a refractive index (n) of 1.93 on the surface of the first SiO ₂ layer. .

While introducing a gas mixture of 60 vol% argon gas and 40 vol% oxygen gas, using polycrystalline silicon as a target, pressure 0.25 Pa, frequency 100 kHz, power density 5.0 W / cm ² , inversion pulse width DC pulse sputtering was performed under the condition of 4.5 μs, and a second SiO ₂ layer having a thickness of 90 nm and a refractive index (n) of 1.46 was formed on the surface of the AZO layer.

On the second SiO ₂ layer, a fluorine-based oil repellent (manufactured by Daikin Industries, Optool DSX) was applied to form an antifouling layer 30 having a thickness of 5 nm, and an antireflection film of Comparative Example 1 was obtained. .
The anti-sublimation film of Comparative Example 1 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

  The antireflection film obtained by the production method of the present invention has a low reflectance and a high transmittance over the entire visible light region, and is excellent in durability and antistatic properties, and the occurrence of discharge is suppressed. It is useful as an antireflection film for LCD, ELD, CRT, and FED.

It is a schematic sectional drawing which shows an example of the antireflection film obtained with the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antireflection film 10 Base material 21 1st oxide layer 22 2nd oxide layer 23 3rd oxide layer

Claims (4)

A step of forming a first oxide layer containing tin oxide and silicon dioxide as main components and having a silicon ratio of 20 to 50 atomic% of the total of tin and silicon (100 atomic%) on the substrate. When,
On the first oxide layer, gallium oxide, indium oxide and tin oxide are the main components, and the ratio of gallium is 2 to 15 atomic% of the total (100 atomic%) of gallium, indium and tin, A second oxide layer in which a ratio of indium is 2 to 15 atomic% in a total (100 atomic%) of gallium, indium, and tin, or a second oxide layer mainly composed of tin oxide; Forming, and
Forming a third oxide layer containing silicon dioxide as a main component on the second oxide layer by a wet coating method.   A coating solution containing at least one selected from the group consisting of silazane, an oligomer of silazane, an alkoxysilane, and an oligomer of alkoxysilane is applied on the second oxide layer, and the third oxide layer is formed. The manufacturing method of the antireflection film of Claim 1 formed. A display screen for displaying images,
A display device comprising: an antireflection film provided by the method for producing an antireflection film according to claim 1 or 2 provided on the viewing side of the display screen. The display device according to claim 3, wherein the antireflection film has a surface resistance value of 10 ⁴ to 10 ¹¹ Ω / □.

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