JP2009211078A - Antireflection film, image display device having the same, optical recording medium, solar power generation module, and method for forming antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily form a monolayer antireflection film having a low refractive index. <P>SOLUTION: The antireflection film which has inorganic oxide fine particles, a binder, a solvent, and pores, and is formed on a substrate, wherein the pore size is 5 to 150 nm and the film thickness of the antireflection film is 60 to 190 nm. As for the antireflection film, the ratio of the pores increases as going from the substrate side to the side of the antireflection film surface, or there is a tendency of the gradual reduction of the refractive index as going from the substrate side to the side of the antireflection film surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antireflection film formed on a substrate and various products using the same.

  Light reflection refers to a phenomenon in which light traveling in one medium changes direction at the boundary with another medium and travels in the original medium. Reflection is closely related to the difference in refractive index between these media. For example, glass, acrylic resin, polyethylene terephthalate (PET) resin, single crystal sapphire, etc. that are transparent and used for image display devices have a large difference in refractive index from air, and it is known that reflection tends to occur between them. Yes.

  And reflections sometimes cause problems for our everyday use. For example, in an aquarium for the purpose of appreciating animals and plants, reflection occurs between glass and air, and if the surroundings are in a bright environment, surrounding objects are reflected and the visibility inside the aquarium is significantly reduced. There is a problem, and particularly when the inside of the aquarium is to be photographed using a light source such as a strobe, the photographer himself is reflected in the aquarium.

  Also, for example, when using a greenhouse with a transparent wall or roof for stable and rapid growth of plants etc., reflection occurs at the boundary between these walls and roof and the air outside the greenhouse, and the inside of the greenhouse In some cases, the amount of sunlight incident on the plant will decrease and the greenhouse effect will be insufficient. For example, approximately 8% of sunlight is reflected on the surface when the wall material is glass, and approximately 10% of sunlight is reflected even on the acrylic resin.

  Further, for example, in an image display device such as a personal computer monitor or television, reflection occurs between the substrate and the air, as in the case of the water tank described above, and the surrounding objects are reflected in a bright environment. There is a problem that it overlaps and the visibility is remarkably lowered.

Here, as a technique for preventing the above-described decrease in visibility, there is a technique for preventing a decrease in visibility in an image display device. This utilizes the interference effect. To put it simply, an antireflection coating layer is provided on the image display device, the refractive index of the substrate in the image display device is n ₁ , and the antireflection coating layer is refracted. In the case where the rate is n ₂ , the reflectance can be theoretically made 0 if n ₂ = √n ₁ is satisfied. Details are disclosed in Patent Document 1 below.

  In consideration of the relationship between this equation and the material actually used, when glass is used as the substrate, the refractive index of glass is 1.5 to 1.7, so the reflectance is theoretically 0. The refractive index of the antireflection film is desirably 1.22 to 1.30. When an acrylic resin is used as the substrate, the refractive index of the acrylic resin is 1.5 to 1.6. The refractive index of the film is preferably 1.22 to 1.26. When PET resin is used as the substrate, the refractive index of the PET resin is about 1.6. Therefore, the refractive index of the antireflection film is about 1. 26 is desirable, and when the single crystal sapphire is used as the substrate, the refractive index of the single crystal sapphire is about 1.8, so that the refractive index of the antireflection film is preferably about 1.33.

  However, with current materials, even fluorine-based resins, which are said to have a relatively low refractive index, are about 1.34, and among inorganic materials, especially magnesium fluoride, which is known for its low refractive index, is about 1.38. It was extremely difficult to obtain sufficient antireflection with a single layer.

  Therefore, as a method for suppressing reflection of the image display device, Non-Patent Document 1 described below improves the function of the antireflection film by stacking a plurality of films having different refractive indexes.

  In recent years, an airgel thin film has been proposed as a film having a low refractive index, which is described in Patent Documents 2 to 6 below. The airgel thin film is a thin film having fine particles having hollows inside (hollow fine particles) and a matrix for holding the hollow fine particles. Since the cavity inside the airgel thin film has substantially the same refractive index as that of air (refractive index 1.0), even if the material of the hollow fine particles or the refractive index of the matrix holding the hollow fine particles is large, As a result, the refractive index is close to that of air. That is, the reflectance can be reduced by forming this film on the substrate.

JP 2002-14381 A JP 2003-149642 A JP 2002-278479 A JP 2002-321910 A JP 2003-119052 A JP 2003-201443 A

Journal of the Japan Printing Society Vol. 40, p. 250, 2003

  However, since the airgel layer has a high porosity, the mechanical strength may be very low. This is because the hollow fine particles have voids for lowering the refractive index, that is, in order to enlarge the internal space, it is necessary to reduce the thickness of the particle shell. It is also necessary to reduce the particle size of the hollow fine particles so as not to prevent the transmission of light incident on the airgel. For this reason, it is necessary to control the ratio of hollow fine particles added, the film thickness, and the like. Furthermore, there is also a special manufacturing process called supercritical drying, which has problems in cost and feasibility, and it is desirable that it can be formed by a simpler process.

  Furthermore, the method of reducing the reflectance by setting the refractive index to the half power of the refractive index of the substrate uses the light interference effect, and therefore it is necessary to adjust the phase condition of the reflected light. Therefore, the thickness of the antireflection film needs to be formed accurately and uniformly. The wavelength range of light that can exhibit antireflection properties is also narrow.

  Moreover, when laminating | stacking using a some layer like the said nonpatent literature 1, since there are several layers from which a refractive index differs, it is necessary to set it as the structure which suppresses reflection in each, increase of a process or design Complexity becomes an issue.

  If the film can be formed by the method of forming voids inside the binder without using hollow fine particles with a very thin shell compared to the film thickness, the mechanical strength is thought to be greatly improved. A method for forming a thick film has not been proposed.

  In addition, the voids are not uniformly present in the film, but if they can be localized near the surface of the antireflection film rather than the surface of the substrate, the refractive index near the substrate increases and the area near the antireflection film decreases. The antireflection function is exhibited even if there is a slight difference in film thickness, and the function can be obtained for light in a wide wavelength range, but at present, an antireflection film having such a gap is used. A method of forming has not been proposed.

  As described above, an object of the present invention is to form an antireflection film having a low refractive index having voids inside a matrix with a simple structure without using hollow fine particles, and to form an antireflection film by a simpler method. Furthermore, it is to produce devices such as a greenhouse, a water tank, an image forming apparatus, and a solar battery panel using the same.

  In order to solve the above-mentioned problems, the present invention is characterized by an antireflection film formed on a substrate having inorganic oxide fine particles, a binder, a solvent, and a void, and the size of the void is 5 nm. The antireflective film has a thickness of 60 nm or more and 190 nm or less, and the antireflective film is an antireflective film in which the void ratio increases from the substrate side to the surface side of the antireflective film.

  A feature of the present invention is an antireflection film formed on a substrate having inorganic oxide fine particles, a binder, a solvent, and voids, and the size of the voids is 5 nm or more and 150 nm or less. The film thickness of the antireflection film is 60 nm or more and 190 nm or less, and the antireflection film is an antireflection film having a refractive index that gradually decreases from the substrate side toward the surface side of the antireflection film.

  A single-layer antireflection film with an extremely low refractive index and antireflection function can be formed by an easy method of coating and thermosetting. In addition, the image display device using this, an optical device such as a DVD disk, and members can be recorded and reproduced with high sensitivity at the same time as reflection is suppressed. In addition, since the image display surface is a polarizing plate, in a liquid crystal display panel that is weak against impact, by providing a transparent substrate (acrylic resin, glass, or the like) with an antireflection film on the surface, reflection can be reduced. It was revealed that the effect of enhancing the impact resistance can also be exhibited.

  In addition, since the reflection is small, sunlight can be used effectively. Therefore, it was found that application to a solar power generation module and a greenhouse produced with a member having this film also have an effect of promoting plant growth.

  Since the resistance of the film is low, it is possible to form a highly dust-proof substrate, which proves effective as an indoor building material.

1 is an outline of an example of a method for forming an antireflection film of the present invention. A cross-sectional photograph of a hydrophilic film formed on a resin. (A) Intensity of elements in the island-shaped region of the hydrophilic film, (B) Intensity of elements in other than the island-shaped region of the hydrophilic film. A greenhouse with an anti-reflection coating. DVD disc provided with an antireflection film. The schematic diagram which looked at the image display device from the top. Schematic of the structure of a mobile phone. The schematic diagram of a structure of a photovoltaic power generation module.

  Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the drawings. However, various modifications using the present invention are possible, and the present invention is not limited to the embodiments and examples.

  The antireflection film according to this embodiment is formed of inorganic oxide fine particles and a binder. Basically, this film is formed by applying and heating at least inorganic oxide fine particles and a paint mixed with a binder and a solvent to a substrate. When the binder is a thermosetting substance such as silica sol, epoxy resin monomer, melamine resin monomer, etc., a very small amount of a catalyst for promoting polymerization, that is, thermal curing of the coating film, is also added to the paint.

  An outline of a method for forming an antireflection film according to the present embodiment will be described with reference to FIG.

  First, the coating material 2 is applied to the substrate 1 to form a coating film. And it heats up promptly. At this time, the solvent is rapidly vaporized in the coating film to generate bubbles 3 in the film. When the coating film is solidified in this state, the bubble portion is held as the gap 4 and the antireflection film 5 according to this embodiment is formed.

  FIG. 2 is a cross-sectional photograph of an example of the antireflection film of the present embodiment, in which an antireflection film is formed on an acrylic substrate. The inorganic oxide is fine particles of silicon oxide, and silica sol is used as the binder. A low refractive index film is formed on the acrylic substrate, and carbon is further formed thereon. Here, carbon is formed only in order to prevent the cross section from being broken when a sample of a cross section in the measurement is prepared, and does not affect the effect of the antireflection film according to the present embodiment.

  In FIG. 2, it can be confirmed that several voids exist inside the low refractive index film. Although the shape of the void is indefinite, the size is approximately 5 to 150 nm. The size of the air gap here is a distance that can be taken longest in the cross section of each air gap, and a straight line along this distance is taken as a major axis.

  Here, in order to confirm that it is a void, the existence strength of the element in the void and the portion that is not the void was measured. The result is shown in FIG.

  As a result of FIG. 3, it was found that the presence strength of carbon, oxygen, silicon, etc. is small in the voids compared to the portions that are not voids. This also confirmed the presence of voids.

  The refractive index can be controlled by changing the ratio of silicon oxide (refractive index: about 1.5) and voids (refractive index: about 1.0) that are the matrix of the film. Specifically, the refractive index decreases as the void ratio increases.

  The formation of voids can also be controlled by the boiling point of the solvent used since the vaporization of the solvent in the coating film during thermal curing contributes to void formation, and the thermosetting temperature after coating the substrate.

  Furthermore, although the tendency can be found in FIG. 2, a lot of voids are formed in a relatively upper part (portion close to the outermost surface) of the film. This is presumably because bubbles that started to form inside the paint on the substrate due to thermosetting, that is, heating, rose to the vicinity of the surface. That is, this means that the refractive index tends to gradually decrease from the substrate side, and even one layer has a refractive index gradient in that layer. As a result, the substrate side has a refractive index closer to that of the substrate, and the surface side which is not the substrate side has a refractive index closer to that of air. As a result, reflection at the interface between the substrate and the antireflection film and each reflection at the interface between air and the antireflection film can be further reduced by a simple method.

  Also, due to this property, when films having different thicknesses are formed using paints having the same composition, the refractive index tends to be lower as the film is thinner when the thermosetting conditions are the same. This is because many voids are easily formed near the surface.

  In order to form many voids not only near the surface but also inside, a method of forming multiple layers is also conceivable. As a result, voids are formed not only in the vicinity of the surface but also in the interior, so that the physical strength of the film is further improved.

The following describes the paint material and details of the film formation.
(1) Coating material The coating material consists of a binder, inorganic oxide fine particles, and a solvent. These are described below.

(1-1) Binder Examples of the coating film material include highly transparent organic or inorganic polymer materials and materials that can be polymerized. In the case of an organic material, when the substrate is a resin, the substrate may swell, deform, or dissolve depending on the solvent used. Also, the hardness of inorganic materials tends to be higher. Therefore, an inorganic material is suitable. In the case of an inorganic material, a material having a low refractive index is advantageous when forming an antireflection film. A silicon-based material is suitable as the low refractive index material.

  Examples of the organic polymer material include thermoplastic polymer materials. Specific examples include acrylic resin, polystyrene, styrene-acrylic copolymer, polyester resin, polyvinyl chloride, ethylene-vinyl acetate copolymer, polyethylene terephthalate resin, polyvinylidene chloride resin, and polycarbonate resin. Examples of the organic polymerizable material include thermosetting polymer materials. Specific examples include aliphatic skeleton polyamic acid derivatives.

  Examples of inorganic polymer materials include silicon compounds having a hydrolyzable residue (generic name is silica sol), titanium compounds having a hydrolyzable residue (general name is titania sol), and the like. These are compounds in which alkoxysilane or alkoxytitanium is polymerized to a molecular weight of about several thousand and are soluble in alcoholic solvents. By heating these, a binder of silicon oxide or titanium oxide can be formed.

  Examples of inorganic polymerizable materials include alkoxysilanes having various substituents such as amino groups, chloro groups, and mercapto groups. Specific materials are shown in the description of the silicon compound having a hydrolyzable residue described later.

  As described above, a silicon-based material is suitable as the binder. Specifically, a silicon compound having a hydrolyzable residue is preferable. Details are described below.

One of the silicon compounds having a hydrolyzable residue is silica sol. This is a substance that changes to silicon oxide by heating. Since the formed silicon oxide has high transparency, it has high light transmittance and is suitable for greenhouses, water tanks, image forming apparatuses, and the like. In addition, the silicon oxide fine particles are easier to disperse inside the film than resins such as acrylic and polycarbonate. When the silicon oxide fine particles cannot be dispersed inside the film, that is, when the particles are aggregated, the film becomes turbid, the incident light is scattered, and the light transmittance is lowered. Next, a general method for preparing silica sol is as follows. When tetraalkoxysilane is heated under mildly acidic conditions, the alkoxy group is hydrolyzed to become a hydroxyl group, which reacts with a nearby alkoxysilane group to form a silicon-oxygen-silicon bond, thereby increasing the molecular weight. In general, the average molecular weight is several thousand.
If the average molecular weight is too low (when the molecular weight is several hundreds), there is a problem that part of the film volatilizes when a silicon oxide film is formed by subsequent heating. Further, if the average molecular weight is too high (when the molecular weight is tens of thousands or more), it becomes insoluble in the solvent to be used, so that it causes a problem of precipitation when formed into a paint.

  Examples of the tetraalkoxysilane used for producing the silica sol include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetraisobutoxysilane, and tetrabutoxysilane. Other than this, a silicon compound having a chlorine group in place of the alkoxysilane group, such as silicon tetrachloride, may also be mentioned.

  Examples of the silicon compound having a hydrolyzable residue other than silica sol include compounds having an amino group, a chloro group, a mercapto group, etc. in addition to tetraalkoxysilane. Specifically, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropylmethyl Dimethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, etc. Is mentioned.

(1-2) Inorganic oxide fine particles Examples of the inorganic oxide fine particles include colorless or white fine particles such as silicon oxide, aluminum oxide, titanium oxide, and cerium oxide. In terms of size, it is desirable that the minor axis of the particles be equal to or less than the average film thickness in order to improve the flatness of the film. Of these, silicon oxide having a relatively low refractive index (refractive index is about 1.5 to 1.7) and aluminum oxide (refractive index is about 1.7 to 1.9) and the like are preferable. Therefore, details of silicon oxide fine particles will be described in particular.

  When the silicon oxide fine particles are spherical, the average particle diameter is desirably 190 nm or less so that visible light (wavelength: 380 to 760 nm) incident on the film is not scattered. Beyond this, incident light is scattered and the film appears cloudy, which may cause problems in application to displays. Even when the silicon oxide fine particles are chain-like, it is desirable that the thickness (thickness in a cross section perpendicular to the stretching direction) be 190 nm or less for the same reason as described above. Note that the transparency improves as the particle diameter of the silicon oxide fine particles is smaller. Therefore, the average particle size is preferably 100 nm or less. In the present invention, the lower limit of the size of the silicon oxide fine particles is about 9 nm because of the available size, but if it is well dispersed in the film, there is no problem even if it is smaller than this.

  By the way, if the dispersibility in the silicon compound having a hydrolyzable residue, which is a matrix used, and a solvent is insufficient, a large secondary particle is formed due to agglomeration, and the film still appears cloudy. is there. Therefore, it is preferable to use a solvent that can disperse the silicon oxide fine particles, if possible. However, depending on the type of the substrate, such a solvent may not be used. Therefore, in such a case, a dispersant is added. Specifically, a nonionic dispersant is suitable. Some ionic dispersants may accelerate the polymerization of silicon compounds with hydrolyzable residues, and the viscosity of the paint increases significantly before application to the substrate, depending on the case, gel or complete In some cases, it is desired to confirm whether or not such a phenomenon occurs in use. In addition, when a dispersant is used, the strength of the film tends to decrease. Therefore, it is desired that the dispersant is not used as much as possible, or that even if it is used, it should be considered as small as possible.

Colloidal silica is suitable as the silicon oxide fine particles. Examples of colloidal silica include Nissan Chemical's organosilica sol and Snowtex. Since these fine particles have many hydroxyl groups on the surface, they are highly hydrophilic. Further, an antireflection film formed using these as a member is hydrophilic and at the same time has a very low resistance. Specifically, it is about 1 × 10 ¹⁰ to 10 × 10 ¹⁰ Ω. This value is as very small as 1 / 10,000 to 1 / 1,000,000 of glass, acrylic resin, polycarbonate resin, PET resin and the like. For this reason, dust such as dust is difficult to adhere. For this reason, in a greenhouse or the like in which the film of the present invention is provided on a transparent surface, the amount of incident light increases, leading to shortening of the plant growth time. In the case of the image forming apparatus, it is possible to enjoy a clear image because dust does not adhere to the surface for a long time even in a dry room. Further, since the transparent substrate provided with the film of the present invention is less likely to adhere dust such as dust, it is effective as an indoor building material such as a wall or partition in a clean room.

  Furthermore, since many hydroxyl groups are present on the surface, compounds having alkoxysilane groups can be bonded in a larger proportion than ordinary glass plates and the like. Therefore, a perfluoropolyether compound-based or perfluoroalkyl compound-based liquid repellent having an alkoxysilane group, which will be described later, can be bonded in a larger proportion than a normal substrate such as glass. Therefore, it is preferable in that the liquid repellency can be improved as compared with a normal glass plate or the like.

  Among colloidal silica, silicon oxide fine particles suitable as a constituent member of an antireflection film are chain-like. When the existing ratio of the film is the same, the refractive index of the formed film can be easily reduced compared to a spherical one. The binder of the film, the so-called holding body is silica sol, and silicon oxide has a very low function as the holding body of the film. Therefore, if there is no silica sol, it is difficult to maintain the shape as a film, and it becomes a simple powder state. Therefore, in order to increase the physical strength of the film, it is preferable that the silicon oxide content in the film is small. Although it is not clear why a chain-like silicon oxide can form a film with a lower refractive index than when a spherical silicon oxide is used, it is easier to form voids in a film than a spherical one. It is presumed that it has a form. An example of the chain-like silicon oxide fine particles is an organosilica sol IPA-ST-UP manufactured by Nissan Chemical.

  In addition to silicon oxide, an aluminum sol having a low refractive index and suitable aluminum oxide is preferable in that an alumina sol having a large number of hydroxyl groups on the surface forms a low resistivity film.

(1-3) Solvent A solvent that can dissolve or uniformly disperse the binder is effective. However, if the substrate is a resin, a ketone, ether, or ester solvent may swell, deform, or dissolve the substrate, so care must be taken. In the case of the paint having the silicon compound having a hydrolyzable residue suitable as the binder and the silicon oxide fine particles suitable as the inorganic oxide fine particles, an alcohol-based solvent is preferable. Specific examples include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, isopentanol, tert-pentanol and the like. Alcohol solvents are preferred because they are difficult to swell, deform and dissolve a substrate formed of polycarbonate, acrylic, or the like. As for the alcohol solvent, the alcohol having a large carbon number tends to have a high boiling point. Further, the boiling point tends to decrease as the number of branches increases. In film formation described later, a film having a lower refractive index is easier to form when the boiling point is slightly lower than the thermosetting temperature. This is because the volume of voids generated in the film accompanying the vaporization of the solvent increases in the film.
(2) Film Formation Method The low refractive index film of this embodiment is formed by pretreatment, coating, and heating of the substrate. In order to further improve the abrasion resistance, post-treatment after heating may be performed. These details are described.

(2-1) Pretreatment In the pretreatment, the substrate is washed and the wettability of the substrate is improved in order to deposit the paint uniformly.
(I) Substrate cleaning In the substrate cleaning, a solvent, a cleaning agent, or the like that dissolves or removes dirt adhering to the substrate is used. However, when the substrate is a resin, for example, acrylic or polycarbonate, an alcohol solvent such as methanol, ethanol, propanol, or butanol is more preferable than a solvent (tetrahydrofuran, dioxane, etc.) that generates fogging by dissolving the surface. If the substrate is glass, it is possible to remove the dirt together by dipping it in a basic solution (for example, sodium hydroxide aqueous solution) and etching the surface thinly. It is preferable to proceed. However, if this is done for a long time, the etching will progress too much and the surface may become cloudy, so care must be taken.
(Ii) Improvement of substrate wettability By improving the wettability of the substrate, the coating material is uniformly applied, so that variations in film thickness are reduced and optical characteristics are improved. In order to improve the wettability of the substrate, there are a surface modification method using a device such as a plasma irradiation apparatus, and a method of chemically modifying the surface using an acid, base solution or the like.
-Surface modification method by equipment Examples of this category include oxygen plasma irradiation, standing in an ozone atmosphere, and UV irradiation. In any case, active oxygen acts on the substrate surface to generate a hydroxyl group, a carboxyl group, or the like. Since these groups are hydrophilic, the surface on which these groups are generated has improved wettability. Therefore, it becomes easy to obtain a film having a uniform thickness by coating. The UV irradiation changes the oxygen in the air to an active state by the UV, and this modifies the surface. Therefore, an effect similar to that of leaving in an oxygen plasma irradiation or ozone atmosphere can be obtained. Other methods include argon plasma. Even when irradiated with argon plasma, wettability is improved. However, when the output of the high frequency power supply of the plasma generator is the same, it is necessary to make the irradiation time longer than that of oxygen plasma.
-Chemically modifying method When glass is immersed in an aqueous sodium hydroxide solution, the silicon-oxygen bond on the surface is broken and hydroxyl groups are generated, improving the wettability. When the acrylic plate is immersed in a base like glass, the wettability is improved, but this principle is that the ester group on the surface is hydrolyzed and the hydrophilicity is improved by exposing the hydroxyl group or the carboxyl group.

(2-2) Application method Application is not particularly limited, such as spin coating, dip coating, bar coating, coating with an applicator, spray coating, and flow coating. In order to control to an appropriate film thickness, it is necessary to optimize the concentration of the paint and the conditions of the respective application methods. In the case of spin coating, the rotation speed and rotation time affect the film thickness. In particular, the influence of the rotational speed is large, and the film tends to be thinner as the rotational speed is increased. In the case of dip coating, the dipping time and the pulling speed affect the film thickness. In particular, the influence of the pulling speed is large, and the film tends to be thinner as the pulling speed is decreased. Appropriate number for bar coating, gap size for applicator coating, spray movement speed for spray coating, angle for holding substrate and usage of paint used for flow coating, etc. Are the individual application conditions.

  The target film thickness during coating is desirably 60 to 190 nm. Theoretically, the film thickness t is reflected when t = λ / 4n where n is the wavelength λ of the incident light and n is the medium on which the light is incident (the refractive index of the transparent substrate and the antireflection film of the present invention). The rate is minimized.

  Incident light is in the visible light region (380 to 760 nm), and the refractive index of the medium is from air (refractive index is about 1.0) to a relatively high refractive index transparent glass substrate (refractive index is about 1.7). Considering the use range of the member, the desirable minimum film thickness is 380 / (4 × 1.7) = 56 nm. If the wavelength is less than 56 nm, the reflectance cannot be sufficiently affected when light in the visible light region is incident. In consideration of the film thickness distribution when the coating film is formed, it is desirable to aim for a minimum film thickness of 60 nm, which is slightly larger than 56 nm. On the other hand, the maximum film thickness is preferably 760 / (4 × 1.0) = 190 and 190 nm. From the above conditions, it is considered that the film thickness of the present invention is appropriately 60 to 190 nm.

(2-3) Heating After the coating step, heating is performed to volatilize the solvent or to advance polymerization depending on the binder. By setting the heating temperature to be equal to or higher than the boiling point of the solvent, bubbles are generated in the film and finally remain as voids in the film, resulting in a reduction in the refractive index of the film.

  By the way, the heating temperature needs to be lower than the heat resistant temperature of the substrate in addition to the boiling point of the solvent, and when a thermosetting material is used as the binder, it needs to be higher than the thermosetting temperature. Therefore, it is necessary to select a solvent, a substrate, and a binder material to meet these requirements. Furthermore, if there is a difference in volumetric shrinkage between the film and the substrate due to cooling after heating, problems such as film peeling and substrate deformation may occur, so the substrate and film are similar in material or linear expansion. It is desirable to select the one with a similar rate. Considering from this point of view, when silica sol suitable as a binder and silicon oxide fine particles suitable as inorganic oxide fine particles are used, the film formed by heating becomes silicon oxide. Quartz is a suitable substrate material.

(2-4) Outline of post-treatment Although the antireflection film of the present invention is formed by thermosetting, the antifouling property of the surface is improved by forming a layer comprising a fluorine-containing compound having liquid repellency. To do. However, the thickness of the layer made of a fluorine-containing compound having liquid repellency needs to be extremely thin so as not to reduce the antireflection effect of the formed antireflection film. Specifically, as described in (2-2), the influence on the reflectance can be avoided by setting the thickness to less than 56 nm.

In addition, the formation form of the layer which consists of a fluorine-containing compound which has liquid repellency has the following two types.
-Coating film comprising a fluorine-containing compound having liquid repellency A method for forming a coating film comprising a fluorine-containing compound having liquid repellency. Liquid repellency is exhibited by coating the surface with a coating film. Therefore, when the antireflection film has a low resistance, the liquid repellent fluorine-containing compound is coated, so that the surface resistance is increased, and as a result, dust such as dust is easily attached.

Examples of the material for forming this film include Cytop (manufactured by Asahi Glass Co., Ltd.), INT304VC (manufactured by INT Screen Corporation), and the like. These are diluted with a solvent, applied, and heated to volatilize the solvent, and in some cases, thermally cured to form a film.
-Perfluoropolyether compound or perfluoroalkyl compound is a method of bonding a perfluoropolyether compound or perfluoroalkyl compound having an alkoxysilane group that can be bonded to a hydroxyl group at the terminal to an antireflection film. Specifically, a compound as shown below is bonded to the antireflection film.

ここで、Ｘはパーフルオロポロエーテル鎖とアルコキシシラン残基との結合部位でＣＯＮＨ−(ＣＨ₂)₃、Ｙはパーフルオロアルキル基とアルコキシシラン残基との結合部位でＣＯＮＨ−(ＣＨ₂)₃，(ＣＨ₂)₂、Ｒはアルキル基である。

Here, X is a bonding site between the perfluoropolyether chain and the alkoxysilane residue, and CONH- (CH ₂ ) ₃ , Y is a bonding site between the perfluoroalkyl group and the alkoxysilane residue, and CONH- (CH ₂ ). ₃ , (CH ₂ ) ₂ and R are alkyl groups.

In this case, the surface of the antireflection film is not completely covered, but a perfluoropolyether chain or a perfluoroalkyl chain grows like grass on the antireflection film. Since the surface of the antireflection film is not completely covered, when the film has a low resistance of 10 ¹¹ Ω or less, the film can maintain a low resistance even after this method is performed.

  Furthermore, by forming these perfluoropolyether chains or perfluoroalkyl chains on the surface, the lubricity of the surface is also improved. Therefore, physical damage of the surface due to rubbing can be alleviated and a surface having high abrasion resistance can be formed.

  From the above, in addition to antifouling properties, low resistance of the surface can be maintained and abrasion resistance can be improved. When forming a liquid repellent layer, a perfluoropolyether compound having an alkoxysilane group at the terminal or a perfluoroalkyl is used. A method using compounds is advantageous.

(2-5) Liquid repellent used in post-treatment As described in (2-4), a perfluoropolyether compound having a terminal alkoxysilane group or a perfluoroalkyl compound is effective as the liquid repellent. The liquid repellent and the liquid repellent film forming method are shown below.
(A) Liquid repellent agent Specific examples of the perfluoropolyether compound having an alkoxysilane group at the terminal or the perfluoroalkyl compound include the following compounds 1 to 12.

  Among these, the compounds 1-8 are obtained by performing the synthesis method shown below. Compounds 9-12 have the compound names 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyl, respectively. Trimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane is marketed by Hydras Chemical. Another commercially available material is Daikin Industries, Ltd. OPTOOL DSX. In addition, compounds 1 to 4 have a perfluoropolyether fluorine chain, and the liquid repellent film formed from the compound having this fluorine chain does not repel even when immersed in engine oil or gasoline for a long period (1000 hours). There is a feature that the aqueousity hardly decreases (the amount of decrease is 5 ° or less). These compounds are represented by the following general formula.

ここで、Ｘはパーフルオロポロエーテル鎖とアルコキシシラン残基との結合部位でＣＯＮＨ−(ＣＨ₂)₃、Ｒはアルキル基である。

Here, X is a bonding site between the perfluoropolyether chain and the alkoxysilane residue, CONH- (CH ₂ ) ₃ , and R is an alkyl group.

  By using the above compound, it is possible to form an antireflection film having a high antifouling property even in an environment where there is a concern of contamination such as engine oil or gasoline.

  When the compounds 5 to 12 are immersed in engine oil or gasoline for a long period (1000 hours), the contact angle with water decreases from before the immersion (about 110 °) to almost the same level as the contact angle of the substrate.

(Synthesis of Compound 1)
DuPont Krytox 157FS-L (average molecular weight 2500) (25 parts by weight) was dissolved in 3M PF-5080 (100 parts by weight), thionyl chloride (20 parts by weight) was added thereto, and the mixture was stirred for 48. Reflux for hours. Thionyl chloride and PF-5080 are volatilized with an evaporator to obtain acid chloride (25 parts by weight) of Krytox 157FS-L. PF-5080 (100 parts by weight), Silaace S330 (3 parts by weight) manufactured by Chisso Corporation, and triethylamine (3 parts by weight) are added to this and stirred at room temperature for 20 hours. The reaction solution was filtered with Radiolight Fine Flow A manufactured by Showa Chemical Industry, and PF-5080 in the filtrate was volatilized with an evaporator to obtain Compound 1 (20 parts by weight).

(Synthesis of Compound 2)
Compound 2 (20 parts by weight) was obtained in the same manner as in the synthesis of Compound 1 except that Chisso Co., Ltd. Silaace S330 (3 parts by weight) was used instead of Chisso Co., Ltd. Silaace S360 (3 parts by weight).

(Synthesis of Compound 3)
Compound similar to the synthesis of Compound 1 except that Daikin Industries' demnum SH (average molecular weight 3500) (35 parts by weight) is used instead of DuPont Krytox 157FS-L (average molecular weight 2500) (25 parts by weight) 3 (30 parts by weight) was obtained.

(Synthesis of Compound 4)
Instead of Chisso Co., Ltd. Silaace S330 (3 parts by weight), Chisso Co., Ltd. Silaace S360 was used. Compound 4 (30 parts by weight) was obtained in the same manner as in the synthesis of Compound 1, except that demnam SH (average molecular weight 3500) (35 parts by weight) was used.

(Synthesis of Compound 5)
Compound 1 except that 7H-dodecafluoroheptanoic acid (molecular weight 346.006) (3.5 parts by weight) manufactured by Daikin Industries, Ltd. was used instead of DuPont's Krytox 157FS-L (average molecular weight 2500) (25 parts by weight) In the same manner as in the synthesis of Compound 5 (3.5 parts by weight) was obtained.

(Synthesis of Compound 6)
Using 7H-dodecafluoroheptanoic acid (molecular weight 346.06) (3.5 parts by weight) manufactured by Daikin Industries, Ltd. instead of Crytox 157FS-L (average molecular weight 2500) (25 parts by weight) manufactured by DuPont, Chisso Corporation ) Compound 6 (3.5 parts by weight) was obtained in the same manner as in the synthesis of Compound 1 except that Chisso Corporation Silaace S320 (2 parts by weight) was used instead of Silaace S310 (2 parts by weight).

(Synthesis of Compound 7)
Compound except for using 9H-hexadecafluorononanoic acid (molecular weight 446.007) (4.5 parts by weight) manufactured by Daikin Industries, Ltd. instead of DuPont's Krytox 157FS-L (average molecular weight 2500) (25 parts by weight) In the same manner as in the synthesis of 1, compound 7 (4.5 parts by weight) was obtained.

(Synthesis of Compound 8)
Instead of DuPont's Krytox 157FS-L (average molecular weight 200) (25 parts by weight), Daikin Industries, Ltd. 9H-hexadecafluorononansan (molecular weight 446.007) (4.5 parts by weight) was used. Compound 8 (4.5 parts by weight) was obtained in the same manner as the synthesis of Compound 1 except that Chisso Corporation Silaace S320 (2 parts by weight) was used instead of Silaace S310 (2 parts by weight).
(B) Liquid repellent film forming method The liquid repellent film forming method using a perfluoropolyether compound having an alkoxysilane group at the terminal or a perfluoroalkyl compound is as follows.

  First, a perfluoropolyether compound having an alkoxysilane group at the terminal or a perfluoroalkyl compound is dissolved in a solvent. The concentration varies depending on the coating method, but is generally about 0.01 to 1.0% by weight. Alkoxysilane groups are gradually hydrolyzed by moisture in the solvent or moisture that enters the solvent from the air, so the solvent should be dehydrated or one that is difficult to dissolve water, such as fluorine-based solvents It is desirable to do. Specific examples of the fluorine-based solvent include 3M FC-72, FC-77, PF-5060, PF-5080, HFE-7100, HFE-7200, and DuPont Vertrel XF. In this way, a liquid in which the perfluoropolyether compound or perfluoroalkyl compound is dissolved (hereinafter referred to as a liquid repellent treatment agent) is prepared.

  Next, a liquid repellent treatment agent is applied to the surface of the antireflection film. As a coating method, a normal coating method such as dip coating or spin coating is used. Then heat. Heating is a condition necessary for the alkoxysilane residue to form a bond with a hydroxyl group or the like on the surface. The heating is usually completed for about 10 minutes at 120 ° C. and for about 30 minutes at 100 ° C. It is about 1 hour at 90 ° C. Although it proceeds at room temperature, it takes a considerable amount of time.

Finally, the surface is rinsed with a fluorine-based solvent, and the excess liquid repellent is removed to complete the liquid repellent treatment. As the solvent used for the rinsing, the solvent presented in the description of the liquid repellent treatment agent can be used.
(3) Applications The antireflection film of this embodiment can be formed on a transparent substrate such as a glass substrate, a polycarbonate resin substrate, or an acrylic resin substrate.

  Therefore, it is effective for applications where it is desired to efficiently capture sunlight without reflecting it. For example, in order to achieve stable and rapid growth of plants and the like, it can be applied to transparent walls such as greenhouses. Alternatively, application to a transparent wall such as an aquarium for the purpose of observing and appreciating animals, plants, insects, seafood and the like in order to suppress reflection (reflection) and improve visibility.

  Similarly, in order to suppress reflection (reflection) and improve visibility, the present invention is applied to a liquid crystal display, a plasma display, an organic display, etc. used in a display such as a television, a mobile phone, a navigation system, a vehicle speed and a rotational speed. Application to an image display device such as a light emitting (organic EL) display can be mentioned. Specifically, it is preferable to form on the outermost surface of the display part of these display devices.

  In addition, in order to improve the power generation efficiency of sunlight, application to an antireflection film formed on the surface of the solar cell panel is mentioned. Since light such as a laser can be efficiently incident in addition to sunlight, it is also effective for the outermost surface of the optical recording medium.

In addition to anti-reflection, the film has a low resistance, so there is also a feature that dust such as dust is difficult to be attached. Therefore, light transmittance is improved and visibility is improved even in a low humidity winter or in a dusty environment. In addition, by imparting liquid repellency, the antifouling property is also improved, and as a result, the light transmittance is improved and the visibility is also improved. Because of these characteristics, the transparent substrate having the film of the present invention is also effective as an indoor building material such as a clean room wall or partition.
〔Example〕
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to these examples.

First, a method for producing an antireflection film on a glass plate will be described.
(1) Pretreatment of coating of antireflection film paint A glass plate having a length of 100 mm, a width of 100 mm, a thickness of 1.1 mm and a refractive index of 1.50 was irradiated with ultraviolet light with a low-pressure mercury lamp. The amount of irradiation light is 10 mW, and the irradiation time is 5 minutes. Thereby, the contact angle with the water of the glass plate surface which received ultraviolet light irradiation became 10 degrees or less. In addition, the contact angle with the water of the glass plate surface before ultraviolet light irradiation was 30-35 degrees.
(2) Preparation of anti-reflective coating Silica sol solution as binder (acidic phosphoric acid, solvent is water: ethanol = 1: 4, alkoxysilane polymer is contained 2.5% by weight) (3 parts by weight), oxidized as inorganic oxide fine particles Silicon dispersion (IPA-ST manufactured by Nissan Chemical Co., Ltd., solid content is 30% by weight) (4 parts by weight) and ethanol (60 parts by weight) are mixed with this paint to form an antireflection film (hereinafter reflective) Preventive paint) is prepared. The boiling point of this paint was 80 ° C.

IPA-ST is a liquid in which spherical colloidal silica-based silicon oxide having a particle diameter of 10 to 15 nm is dispersed.
(3) Application of anti-reflective coating This coating is applied by spin coating to the glass plate subjected to the pretreatment of (1). The spin coating conditions are initially at a rotation speed of 350 rpm for 5 seconds, and subsequently at a rotation speed of 1200 rpm for a rotation time of 20 seconds. The applied paint spread almost uniformly on the glass plate by visual inspection.
(4) Heating After spin coating, the glass plate is immediately placed in a thermostat controlled at 160 ° C. and heated for 10 minutes. As a result, the silica sol is changed to silicon oxide, and the thermosetting is completed. Thus, a glass plate having an antireflection film formed on the surface is completed.
(5) Treatment on the back side Turn over the glass plate with the antireflection film on the surface and perform the above-mentioned treatments (1), (3), (4) to form the same antireflection film on the back side. did.
(6) Evaluation experiment When the film thickness and refractive index of the antireflection film formed on the glass plate were measured, each was 120.
nm and 1.327. The film thickness and refractive index were measured using an ellipsometer (model DHA-OLX) manufactured by Mizojiri Optical Industry. However, the refractive index obtained by this method is the refractive index of the entire film.

  The reflectance of the glass plate on which the antireflection film was formed was measured. The reflectance at 550 nm, which is said to have the highest human visibility, was measured. As a result, the reflectance of the glass plate provided with the antireflection film was 3.1%. The reflectance of the glass plate without the antireflection film was 8%, and it was confirmed that the film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 150 nm were confirmed as shown in FIG. When the cross section of the film was observed, the number of voids was small on the substrate side, and the ratio of voids increased toward the surface side. As a result, a film having a refractive index close to that of the film material on the substrate side and close to air on the surface side could be obtained. As a result, it is assumed that the difference in refractive index at each interface can be reduced and reflection at each interface can be prevented. In the following examples, the distribution of voids in the film was the same.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%. The measurement was performed according to ASTM D-257.

  By the way, even if the heating temperature is not 160 ° C. but 230 ° C. (temperature higher by 150 ° C. than the boiling point of the paint), the film formed is colorless and transparent by visual confirmation. However, when the heating temperature was 240 ° C. (temperature higher by 160 ° C. than the boiling point of the paint), the formed film was slightly turbid. This is presumed to be because the heating temperature is too high and the bubbles become larger, and as a result, the bubbles appear to be cloudy. This indicates that the heating temperature is desirably the boiling point of the paint + 150 ° C. or less.

  An antireflection film was formed on the single crystal sapphire plate in the same manner as in (1) to (5) of Example 1 except that a single crystal sapphire plate (refractive index: 1.768) was used instead of the glass plate.

  Next, this film was evaluated in the same manner as in Example 1 (6). As a result, when the film thickness and refractive index of the antireflection film formed on the single crystal sapphire plate were measured, they were 120 nm and 1.327, respectively.

  The reflectance at 550 nm of the single crystal sapphire plate on which the antireflection film was formed was measured. As a result, the reflectance of the single crystal sapphire plate provided with the antireflection film was less than 0.3%. The reflectance of the single crystal sapphire plate without the antireflection film was 16%, and it was confirmed that the film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 150 nm was confirmed in the same manner as the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  Example 1 except that the silicon oxide dispersion used is IPA-ST-ZL (4 parts by weight) made by Nissan Chemical instead of IPA-ST (4 parts by weight) made by Nissan Chemical when preparing the antireflection paint to be used. The antireflection film was formed on the glass plate in the same manner as (1) to (5). IPA-ST-ZL is a liquid in which spherical colloidal silica-based silicon oxide having a particle diameter of about 100 nm is dispersed, and the solid content in the liquid is 30% by weight. The boiling point of the paint prepared in this example was 80 ° C.

  Next, this film was evaluated in the same manner as in Example 1 (6). As a result, when the film thickness and refractive index of the antireflection film formed on the glass plate were measured, they were 190 nm and 1.295, respectively.

  The reflectance at 550 nm of the glass plate on which the antireflection film was formed was measured. As a result, the reflectance of the glass plate provided with the antireflection film was 2.1%. The reflectance of the glass plate without the antireflection film was 8%, and it was confirmed that this film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 200 nm was confirmed as in the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 5 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  When preparing the antireflection paint to be used, the silicon oxide dispersion used is replaced by Nissan Chemical MT-ST (4 parts by weight) instead of Nissan Chemical IPA-ST (4 parts by weight). An antireflection film was formed on the glass plate in the same manner as 1) to (5). MT-ST is a liquid in which spherical colloidal silica-based silicon oxide having a particle diameter of 10 to 15 nm is dispersed, and the solid content in the liquid is 30% by weight. The boiling point of the paint prepared in this example was 79 ° C.

  Next, this film was evaluated in the same manner as in Example 1 (6). As a result, when the film thickness and refractive index of the antireflection film formed on the glass plate were measured, they were 130 nm and 1.328, respectively.

  The reflectance at 550 nm of the glass plate on which the antireflection film was formed was measured. As a result, the reflectance of the glass plate provided with the antireflection film was 5.1%. The reflectance of the glass plate without the antireflection film was 8%, and it was confirmed that this film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 200 nm was confirmed as in the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

Example 1 except that the silicon oxide dispersion used was replaced by Nissan Chemical IPA-ST-UP (4 parts by weight) instead of Nissan Chemical IPA-ST-UP (4 parts by weight) in preparing the antireflection coating to be used. The antireflection film was formed on the glass plate in the same manner as (1) to (5). IPA-ST-UP is a liquid in which a chain colloidal silica-based silicon oxide having a thickness of 9 to 30 nm is dispersed, and the solid content in the liquid is 15% by weight. The paint prepared in this example had a boiling point of 80 ° C.

  Next, this film was evaluated in the same manner as in Example 1 (6). As a result, when the film thickness and refractive index of the antireflection film formed on the glass plate were measured, they were 76 nm and 1.241, respectively.

  The reflectance at 550 nm of the glass plate on which the antireflection film was formed was measured. As a result, the reflectance of the glass plate provided with the antireflection film was less than 0.3%. The reflectance of the glass plate without the antireflection film was 8%, and it was confirmed that this film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 200 nm was confirmed as in the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 3 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  By the way, even if the heating temperature is not 160 ° C. but 230 ° C. (temperature higher by 150 ° C. than the boiling point of the paint), the film formed is colorless and transparent by visual confirmation. However, when the heating temperature was 240 ° C. (temperature higher by 160 ° C. than the boiling point of the paint), the formed film was slightly turbid. This is presumed to be because the heating temperature is too high and the bubbles become larger, and as a result, the bubbles appear to be cloudy. From this, it was shown that the heating temperature in this example is preferably the boiling point of the paint + 150 ° C. or less.

  (1) to (5) of Example 5 except that the addition amount of IPA-ST-UP manufactured by Nissan Chemical Co., Ltd., which is the silicon oxide dispersion used, is changed from 4 parts by weight to 8 parts by weight when preparing the antireflection paint to be used. ) To form an antireflection film on the glass plate. The paint prepared in this example had a boiling point of 80 ° C.

  Next, this film was evaluated in the same manner as in Example 1 (6). As a result, when the film thickness and refractive index of the antireflection film formed on the glass plate were measured, they were 98 nm and 1.200, respectively.

  The reflectance at 550 nm of the glass plate on which the antireflection film was formed was measured. As a result, the reflectance of the glass plate provided with the antireflection film was 0.6%. The reflectance of the glass plate without the antireflection film was 8%, and it was confirmed that this film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 150 nm was confirmed in the same manner as the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  In Examples 1 and 3 and this example, the silicon oxide fine particles used in the film have a ratio of 94%. The refractive index of the formed film is 1.327 in the case of Example 1, 1.255 in the case of Example 3, and 1.200 in the present example, and the refractive index of the film of this example is low. In Examples 1 and 3, the shape of the silicon oxide fine particles is spherical, and this example is a chain. In Example 5, even when the amount of chain silicon oxide added was half, the refractive index was 1.241, which was lower than that of the films formed in Examples 1 and 3. In the film of the present invention, the lower the proportion of silica sol as a support, the lower the physical strength of the film, the greater the proportion of silicon oxide present. By using this, it is possible to form a low refractive index film that suppresses a decrease in physical strength as much as possible. Therefore, it was shown that the shape of the silicon oxide fine particles is preferably a chain in that the refractive index can be easily reduced even at the same existence ratio.

  Example 5 except that the amount of addition of IPA-ST-UP manufactured by Nissan Chemical Co., Ltd., which is a silicon oxide dispersion, is changed from 4 parts by weight to 1.5 parts by weight or 2 parts by weight when preparing the antireflection paint to be used. The antireflection film was formed on the glass plate in the same manner as (1) to (5). The boiling point of the paint prepared in this example was 80 ° C.

  Next, this film was evaluated in the same manner as in Example 1 (6). As a result, when the film thickness and refractive index of the antireflection film formed on the glass plate were measured, the film in which the amount of IPA-ST-UP added was 1.5 parts by weight was 60 nm and 1.326, respectively. Moreover, the film | membrane whose addition amount of IPA-ST-UP was 2 weight part was 67 nm and 1.281, respectively. The proportion of silicon oxide fine particles used in the film is 75% for the 1.5 parts by weight film and 80% for the 2 parts by weight film. In Example 5, the film thickness and refractive index of the film having the IPA-ST-UP addition amount of 4 parts by weight are 76 nm and 1.241, respectively, and the existing ratio of the used silicon oxide fine particles in the film is 89%. is there. The film thickness and refractive index of the film in which the amount of IPA-ST-UP added in Example 6 is 8 parts by weight are 98 nm and 1.200, respectively, and the existence ratio of the silicon oxide fine particles used in the film is 94%. is there.

  From the above, when chain silicon oxide is used, the existence ratio of chain silicon oxide in the film must be 75% or more so that the refractive index of the formed film is 1.33 or less. Indicated.

A method of forming an antireflection film on an acrylic plate instead of a glass plate will be described.
(1) Pretreatment for coating of antireflection film A 5 mm thick acrylic plate (manufactured by ASONE) was cut into a length of 100 mm and a width of 100 mm. An antireflection film is formed on this substrate by the following method. The refractive index of this substrate was 1.52.

First, the acrylic plate was placed on a hot plate heated to 80 ° C., and then irradiated with ultraviolet light with a low-pressure mercury lamp. The amount of irradiation light is 10 mW, and the irradiation time is 10 minutes. Thereby, the contact angle with the water of the acrylic board surface which received ultraviolet light irradiation became 40 degrees or less. In addition, the contact angle with the water of the acrylic board surface before ultraviolet light irradiation was 90-92 degrees.
(2) Preparation of anti-reflection paint Silica sol solution (acidic phosphate, solvent is water: ethanol = 1: 4, alkoxysilane polymer is contained 2.5% by weight) (3 parts by weight), silicon oxide dispersion (Nissan Chemical) IPA-ST-UP manufactured, solid content is 15% by weight) (4 parts by weight) and ethanol (60 parts by weight) are mixed to prepare a coating (hereinafter referred to as antireflection coating) to form an antireflection film. Is done. The boiling point of the paint prepared in this example was 80 ° C.
(3) Application of anti-reflective coating This coating is applied by spin coating to the acrylic plate subjected to the pretreatment of (1). The spin coating conditions are initially at a rotation speed of 350 rpm for 5 seconds, and subsequently at a rotation speed of 1200 rpm for a rotation time of 20 seconds. The applied paint spread almost uniformly on the acrylic plate by visual inspection.
(4) Thermosetting After spin coating, the acrylic plate is immediately placed in a thermostat controlled at 95 ° C. and heated for 30 minutes. As a result, the silica sol is changed to silicon oxide, and the thermosetting is completed. Thus, an acrylic plate having an antireflection film formed on the surface is completed.
(5) Treatment on the back side The acrylic plate with the antireflection film formed on the front surface is turned over, and the above treatments (1), (3), and (4) are performed to form the same antireflection film on the back surface. did.
(6) Evaluation Experiment Next, this film was evaluated in the same manner as (6) of Example 1. As a result, when the film thickness and refractive index of the antireflection film formed on the acrylic plate were measured, they were 86 nm and 1.245, respectively.

  The reflectance at 550 nm of the acrylic plate on which the antireflection film was formed was measured. As a result, the reflectance of the acrylic plate provided with the antireflection film was less than 0.3%. The reflectance of the acrylic plate without the antireflection film was 8.2%, and it was confirmed that this film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 150 nm was confirmed in the same manner as the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 3 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  From this example and Examples 1 to 5, it was shown that the antireflection film can be formed regardless of whether the substrate is made of glass or acrylic.

A method of forming an antireflection film on a polycarbonate plate instead of a glass plate will be described.
(1) Pretreatment of coating of antireflection film paint A polycarbonate plate (manufactured by Fujimoto Chemical Co., Ltd.) having a thickness of 0.5 mm was cut into a length of 200 mm and a width of 200 mm. An antireflection film is formed on this substrate by the following method. The refractive index of this substrate was 1.54.

First, the polycarbonate plate was placed on a hot plate heated to 80 ° C., and then irradiated with ultraviolet light with a low-pressure mercury lamp. The amount of irradiation light is 10 mW, and the irradiation time is 10 minutes. Thereby, the contact angle with the water of the polycarbonate plate surface which received ultraviolet light became 30 degrees or less.
In addition, the contact angle with the water of the polycarbonate plate surface before ultraviolet light irradiation was 88-90 degrees.
(2) Preparation of anti-reflection paint Silica sol solution (acidic phosphate, solvent is water: ethanol = 1: 4, alkoxysilane polymer is contained 2.5% by weight) (3 parts by weight), silicon oxide dispersion (Nissan Chemical) IPA-ST-UP manufactured, solid content is 15% by weight) (4 parts by weight) and ethanol (60 parts by weight) are mixed to prepare a coating (hereinafter referred to as antireflection coating) to form an antireflection film. Is done. The paint prepared in this example had a boiling point of 80 ° C.
(3) Application of anti-reflective coating This coating is applied to the polycarbonate plate subjected to the pretreatment of (1) by spin coating. The spin coating conditions are initially at a rotation speed of 350 rpm for 5 seconds, and subsequently at a rotation speed of 1200 rpm for a rotation time of 20 seconds. The applied paint spread almost uniformly on the polycarbonate plate by visual inspection.
(4) Thermosetting After spin coating, the polycarbonate plate is immediately placed in a thermostat controlled at 120 ° C. and heated for 20 minutes. As a result, the silica sol is changed to silicon oxide, and the thermosetting is completed. Thus, a polycarbonate plate having an antireflection film formed on the surface is completed.
(5) Treatment on the back side The polycarbonate plate with the antireflection film formed on the front surface is turned over, and the above treatments (1), (3), and (4) are performed to form the same antireflection film on the back surface. did.
(6) Evaluation Experiment Next, this film was evaluated in the same manner as (6) of Example 1. As a result, when the film thickness and refractive index of the antireflection film formed on the polycarbonate plate were measured, they were 82 nm and 1.243, respectively.

  The reflectance at 550 nm of the polycarbonate plate on which the antireflection film was formed was measured. As a result, the reflectance of the polycarbonate plate provided with the antireflection film was less than 0.3%. The reflectance of the polycarbonate plate without the antireflection film was 8.4%, and it was confirmed that this film had an antireflection function.

  When the cross section of the formed antireflection film was observed with a TEM, a void having a size of 5 to 150 nm was confirmed in the same manner as the film of Example 1.

When the surface resistivity of the formed antireflection film was measured, it was 3 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  This example and Examples 1 to 5 and 8 show that the antireflection film can be formed regardless of whether the substrate is made of glass or a resin such as acrylic or polycarbonate.

The liquid repellent treatment is performed on the plate formed with the antireflection film prepared in Examples 1 to 6 and Examples 8 and 9.
(1) Preparation of liquid repellent treatment solution First, a 0.5% by weight solution of compounds 1 to 12 (solvent: Fluorinert PF-5080 manufactured by 3M) is prepared. Let these be liquid-repellent treatment liquids. Further, a 0.1 wt% PF-5080 solution of Compound 1 is a liquid repellent treatment liquid [1], a 0.1 wt% PF-5080 solution of Compound 2 is a liquid repellent treatment liquid [2],. A 1 wt% PF-5080 solution is designated as a liquid repellent treatment liquid [12].

Next, for comparison, a 0.1% solution of Cytop CTL-107M manufactured by Asahi Glass Co., Ltd. was used as the liquid repellent treatment [13].
(2) When using the liquid repellent treatment method and the liquid repellent treatment liquids [1] to [12] Each substrate is immersed in the liquid repellent treatment liquid for 3 minutes. The substrate is taken out and the inside is left in a constant temperature bath heated to 95 ° C. for 30 minutes. The substrate is taken out, the surface is rinsed with PF-5080, and the excess liquid repellent treatment liquid is removed to complete the treatment.
When using the liquid repellent treatment liquid [13] Each substrate is immersed in the liquid repellent treatment liquid for 3 minutes. The substrate is taken out, and the inside is left in a constant temperature bath heated to 95 ° C. for 90 minutes. The substrate is taken out and the processing is completed.
(3) Evaluation of liquid repellency The liquid repellency of the surface of the substrate after the liquid repellency treatment was evaluated by the contact angle with water. The results are shown in Tables 1-8.

  The contact angle with water before the liquid repellent treatment, the refractive index and the reflectance before and after the liquid repellent treatment, and the pencil hardness are also shown.

  Before the liquid-repellent treatment, the antireflection film had a contact angle with water of less than 10 °. However, the contact angle became large in any film by the liquid repellent treatment. Since the refractive index and the reflectance did not change before and after the liquid repellent treatment, it was shown that the liquid repellent treatment does not deteriorate the performance related to these.

However, those treated with a 0.1% solution of Cytop CTL-107M showed higher resistance. This is because Cytop CTL-107M almost completely coats the surface of the antireflection film, whereas compounds 1 to 12 have lyophobic fluorine-based chains attached to the antireflection film surface via alkoxysilane groups. Therefore, as a result, it is considered that the antireflection film is not completely covered.
As the film resistance increases, the resulting film is easily charged, so that there is a problem that dust and dust are likely to adhere. Therefore, compounds 1 to 12 that do not increase the film resistance are less likely to adhere dust and dust to the film. Is preferable in that it can be maintained.

  From the above, it was shown that a fluorine-based compound having an alkoxysilane group at the terminal is preferable in that the film resistance is not increased even when liquid repellency is imparted.

  Next, looking at the pencil hardness of the film, the film with the liquid repellent treatment with the compounds 1 to 12 has a higher pencil hardness than the film without the treatment, but the film treated with Cytop CTL-107M has the liquid repellent treatment. It was the same level of abrasion resistance as the previous one. From the above, it has been clarified that the rub resistance is improved by this liquid repellent treatment.

  When compared with the compounds used in the liquid repellent treatment, the contact angle tends to be high when the compounds 1 to 4 are used. At least 88 ° when the film of Example 2 is treated with the compound 1 or 2 is used. Met. In particular, when compounds 3 and 4 were used, the contact angle was high, and any film showed a contact angle of 100 ° or more. Compounds 1 to 4 are compounds having a perfluoropolyether chain, and others are compounds having a perfluoroalkyl chain or a fluoroalkyl chain. From this, it was shown that a film having excellent liquid repellency can be formed by liquid repellency treatment with a compound having a perfluoropolyether chain.

  When preparing the antireflection paint to be used, ethanol used is not 60 parts by weight, but 30 parts by weight, and the size of the substrate is 500 mm in length and 500 mm in width, and (1) to (5) of Example 8 Similarly, antireflection films were formed on both sides of the acrylic plate.

  Next, when the film thickness and refractive index of this film were measured in the same manner as in Example 6 (6), they were 140 nm and 1.245, respectively.

  Next, the reflectance at 700 nm of the acrylic plate on which the antireflection film was formed was measured. In plant photosynthesis, P700, a kind of chlorophyll in the leaves, is an important factor that drives the electron transfer cycle of the photosynthesis cycle. When irradiated with light having a wavelength of 700 nm and nearby wavelengths, the photosynthesis cycle is actively activated. Make it progress. Therefore, photosynthesis proceeds as the leaves of the plant are irradiated with light having a wavelength of 700 nm and in the vicinity thereof.

  As a result, the reflectance of the acrylic plate provided with the antireflection film was less than 0.3%. The reflectance of the acrylic plate without the antireflection film was 8.1%, and it was confirmed that this film had an antireflection function.

  Next, several acrylic plates on which the antireflection film is formed are produced. Using this, the greenhouse shown in FIG. 4 is produced.

  A tomato seedling 8 is planted in a flower pot 7 in the greenhouse 6. A greenhouse of the same size is made of an acrylic plate that does not form an antireflection film. In early May, pots planted with tomato seedlings (variety: small tomatoes) grown to a similar degree were placed in these greenhouses, and installed in such a manner that sunlight was radiated to these greenhouses to a similar degree. As a result, the tomato seedlings that were placed in a greenhouse made of an acrylic plate formed with an antireflection film gave a red fruit on June 15, but the greenhouse made of an acrylic plate without an antireflection film formed. The tomato seedlings placed on the plant had red fruits since July 3rd. From this, it was confirmed that this antireflection film has an effect of promoting plant growth.

Prepare two acrylic plates 500mm long, 500mm wide and 5mm thick. Of these, an antireflection film is formed on one side in the same manner as in Example 11. These two pieces are inclined at 45 ° and installed in the bedroom of the house. The bedroom has 12 tatami mats and two futons, and they are used to sleep every day. The futon is installed in the center of the room, and the acrylic board is installed at the edge of the room. The weight of the acrylic plate was measured carefully so that dust accumulated after 30 days had passed after the installation, the dust was removed, and the weight of the acrylic plate was measured again. The weight of accumulated dust was determined from the difference in weight before and after dust removal.
As a result, 22 mg of dust accumulated in the case of the acrylic plate on which the antireflection film was not formed. However, in the case of an acrylic plate having an antireflection film, the accumulated dust was 5 mg. The surface resistivity of the acrylic plate without the antireflection film was 1 × 10 ¹⁶ Ω or more, but the surface resistivity of the acrylic plate with the antireflection film was 3 × 10 ¹⁰ Ω, It shows that the surface resistance is reduced by the prevention film and the adhesion of dust due to charging is suppressed. As described above, since the substrate having this antireflection film is excellent in dustproof property, it is shown that this substrate is effective as an indoor building material for normal living, and further, as an indoor building material for producing clean room walls and partitions. It was done.

  When preparing the antireflection paint to be used, the antireflection film is applied only to the surface of the polycarbonate plate in the same manner as in (1) to (4) of Example 9 except that the ethanol used is not 60 parts by weight but 80 parts by weight. Formed.

  Next, the reflectance at 405 nm of the polycarbonate plate on which the antireflection film was formed was measured. In DVD recording / reproduction, light of 405 nm has recently started to be used for the purpose of improving the recording density. Therefore, when a disk is manufactured using a substrate having a high reflectance of light of this wavelength, it is necessary to increase the light intensity during recording / reproduction. To increase the irradiation intensity without changing the laser output, the irradiation time of light to each pit can be increased, but this is negative for high-speed recording / reproduction. Therefore, reducing the reflectance of light of this wavelength is one technique that enables recording / reproduction at high speed.

  The reflectance of the polycarbonate plate on the side provided with the antireflection film of this example was less than 0.3%. The reflectance on the side without the antireflection film was 4.2%, and it was confirmed that this film had an antireflection function.

  Next, another substrate is produced. Further, these substrates are cut into a circle having a diameter of 120 mm, and then formed so that the protective layer and the recording layer are sandwiched between the back surfaces of the two polycarbonate plates, thereby producing a DVD disc. A schematic cross-sectional view of this DVD disc is shown in FIG.

  In this DVD disc, a protective layer 11 and a recording layer 12 are formed on a polycarbonate substrate 10 on which the antireflection film 9 is formed. When test data was written on this disk and then played back, playback was performed with a light intensity of 0.5 mW, which is half that of the prior art, but the read data was accurate. When similar reproduction is performed on a normal disk, a read error occurs. This is because the reading light reaching the light receiving portion of the reproducing apparatus is weakened because of the large reflection on the surface. Usually, since 1 mW light is used, there is no problem in reading, but the above-mentioned trouble occurs when the reading light is halved. Since the DVD disk provided with this antireflection film has very small reflection, it is considered that most of the readout light can be input to the light receiving unit of the reproducing apparatus, and thus the above-described failure is less likely to occur.

  From the above, it was confirmed that by using this film, it is possible to produce a high-sensitivity optical recording medium that can be read even if the reading light intensity of the DVD is halved.

  Example 5 except that a glass plate having a length of 460 mm, a width of 770 mm, a thickness of 4 mm and a refractive index of 1.52 is used instead of the glass plate having a length of 100 mm, a width of 100 mm, a thickness of 1.1 mm and a refractive index of 1.50. Thus, a glass plate having antireflection films formed on both sides is prepared.

  Next, two 32-inch plasma television monitors (H32-P5000 manufactured by Hitachi, Ltd.) are prepared, and one outermost glass plate is removed, and a glass plate having antireflection films formed on both sides is mounted instead. This monitor becomes one of the image display devices.

  A monitor with an exchanged glass plate and a monitor with no exchange were installed near the window and so that sunlight was irradiated on the screen at the same level. As a result, compared to a monitor that does not replace the glass plate, the monitor with the replaced glass plate suppresses the reflection of sunlight incident on the antireflection film on the surface. It became a level that should not be.

  From the above, it was shown that the plasma television monitor provided with this antireflection film can suppress the reflection of the surroundings on the screen even when strong sunlight enters and can display a clear image.

  An acrylic plate having an antireflection film formed on both sides is prepared in the same manner as in Example 8 except that the size of the acrylic plate used is changed to 100 mm long and 100 mm wide, not 460 mm long and 770 mm wide.

  Next, two 32-inch liquid crystal television monitors (W32-L5000 manufactured by Hitachi, Ltd.) are prepared, and an acrylic plate having antireflection films formed on both surfaces is attached to the outermost surface of one panel as shown in FIG.

This is one of the image display devices. An acrylic plate 15 having an antireflection film formed on both sides is provided on the monitor 13 via a spacer 14 having a height of 1 mm. Note that a polarizing plate 16 is provided on the outermost surface of the monitor, and this surface is roughened so that reflected light is scattered.

  Next, an acrylic plate not formed with an antireflection film is applied in the same manner.

  A monitor with an acrylic plate with an antireflective film attached and a monitor with an acrylic plate without an antireflective film were installed at the window and so that sunlight was irradiated on the screen at the same level. As a result, compared to a monitor with an acrylic plate with no antireflection film attached, the monitor with an acrylic plate with an antireflection film is used to suppress the reflection of sunlight incident on the antireflection film on the surface. , Reflection of the surroundings on the screen has become a level that I hardly notice.

  From the above, it was shown that a liquid crystal television monitor provided with this antireflection film can suppress the reflection of the surroundings on the screen even when strong sunlight enters and can display a clear image.

  From Example 13 and this example, it was shown that this antireflection film functions as an antireflection film of an image display device.

  In order to examine the impact resistance of the image display surface of the 32-inch liquid crystal television monitor prepared in Example 14 and the 32-inch liquid crystal television monitor to which the acrylic plate formed with the antireflection film produced in Example 14 was attached, I tried an experiment.

  First, the image display surfaces of the two monitors are fixed to the floor. Next, an iron ball having a diameter of 50 mm is held at a height of 1 m from the image display surface of the monitor. By releasing the holding of the iron ball from this position, the iron ball falls and collides with the image display surface. After that, I switched on the LCD TV monitor and tried to display the image.

  Then, when a normal liquid crystal television collided with the polarizing plate on the image display surface, the glass inside the glass broke, and the image could not be displayed normally. However, the 32-inch liquid crystal television monitor to which the acrylic plate on which the antireflection film was formed normally displayed an image. Moreover, although the collision part of the iron ball was slightly scratched, there was no problem in seeing the image.

  From the above, it was confirmed that an image display device having a transparent substrate having this antireflection film is also excellent in impact resistance.

  Anti-reflective coating using a 43mm long, 34mm wide, 0.3mm thick, and 1.50 refractive index glass plate instead of a 100mm long, 100mm wide, 1.1mm thick, and 1.50 refractive index glass plate An antireflection film is formed on one surface of the glass plate using the same method as in (1), (3), and (4) of Example 1 except that the paint of Example 5 is used.

  Subsequently, the acrylic plate provided on the outermost surface of the image display unit of the mobile phone is removed. Next, the glass plate which has the said anti-reflective film is stuck on the polarizing plate under it using polyisobutylene as an adhesive agent.

  Subsequently, both sides of the acrylic plate were used in the same manner as in (1) to (5) of Example 8 except that the acrylic plate removed from the mobile phone was used instead of the acrylic plate having a length of 100 mm, a width of 100 mm, and a thickness of 5 mm. An antireflection film was formed on the substrate. This acrylic board is mounted on the mobile phone again. In this way, a cellular phone subjected to antireflection treatment is manufactured. FIG. 7 shows an example of the configuration of this mobile phone.

  An acrylic plate 18 is provided on the outermost surface of the image display portion 17, and a glass plate 19 on which an antireflection film is formed is attached to the polarizing plate 20. This mobile phone is operated by the operation part 21.

  If the image display part of this mobile phone or a mobile phone that has not been subjected to anti-reflection processing is placed in direct sunlight, the reflection of the surrounding scenery will strongly affect the mobile phone that has not been subjected to anti-reflection processing. It was difficult. However, mobile phones with anti-reflective treatment were easy to recognize images because of the weak reflection of surrounding scenery. From the above, it was shown that the cellular phone having this antireflection film can easily recognize the image because the surrounding scenery is weak even when the image display part is exposed to direct sunlight.

  Here, when the antireflection treatment was not applied to the acrylic plate, although reflection was slightly anxious, reflection was suppressed by the amount of the glass plate having the antireflection film attached to the polarizing plate.

  Since the PDA or the like is not limited to the mobile phone and has an image display portion having the same configuration, the same effect as in this embodiment can be obtained.

  From the above, it was shown that the portable image display terminal having this antireflection film has an image display portion with a high visibility with little reflection in the outdoors with strong direct sunlight.

  Two solar power generation modules are prepared, and one removes the glass substrate. An antireflection film is formed in the same manner as in Example 5 except that a glass substrate removed from the photovoltaic module is used instead of a glass plate having a length of 100 mm, a width of 100 mm, a thickness of 1.1 mm, and a refractive index of 1.50. . Thereafter, the glass substrate on which the antireflection film is formed is mounted again on the photovoltaic power generation module. A schematic diagram of the configuration of this photovoltaic power generation module is shown in FIG.

  A surface electrode 23, an upper photoelectric conversion layer 24, an intermediate transparent electrode 25, a lower photoelectric conversion layer 26, and a back electrode 27 are formed under the glass substrate 22 on which the antireflection film is formed.

  Next, after arrange | positioning the said two photovoltaic power generation modules so that sunlight might be irradiated to the same extent, the electric power generation amount was measured. As a result, the module replaced with the glass plate on which the antireflection film was formed had a power generation amount of about 10% larger than the module without replacement.

  When the average of the reflectance at a wavelength of 400 to 700 nm of the glass substrate on which the antireflection film was formed and the glass substrate on which the antireflection film was not formed was 10%, the glass substrate on which the antireflection film was not formed was 10%. The glass substrate on which the film was formed was 0.5%. From this, it is considered that the amount of power generation is improved in that sunlight can be taken into the photoelectric conversion layer without reflecting.

  From the above, it was shown that the solar power generation module having this antireflection film can generate power with high efficiency because of less reflection on the glass substrate surface.

  When preparing the antireflection coating, instead of the silica sol solution (3 parts by weight), aminopropyltriethoxysilane (S330 manufactured by Chisso) (0.1 part by weight) and a dispersion of silicon oxide were added to Nissan Chemical IPA-ST ( An antireflection paint is prepared in the same manner as in Example 1, except that IPA-ST-UP (4 parts by weight) manufactured by Nissan Chemical Industries is used instead of 4 parts by weight.

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 80 nm and 1.251, respectively. The reflectance at 550 nm was less than 0.3%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 150 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  In preparing the antireflection coating, N- (2-aminoethyl) -3-aminopropyltriethoxysilane (S320 manufactured by Chisso) (0.1 part by weight), silicon oxide instead of the silica sol solution (3 parts by weight) An antireflective coating is prepared in the same manner as in Example 1 except that the dispersion is replaced with Nissan Chemical IPA-ST-UP (4 parts by weight) instead of Nissan Chemical IPA-ST (4 parts by weight).

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 81 nm and 1.252, respectively. The reflectance at 550 nm was less than 0.3%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 160 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  In preparing the antireflection coating, instead of silica sol solution (3 parts by weight), 3-chloropropyltrimethoxysilane (S620 manufactured by Chisso Corporation) (0.1 part by weight) and silicon oxide dispersion were added to IPA- An antireflection paint is prepared in the same manner as in Example 1, except that IPA-ST-UP (4 parts by weight) manufactured by Nissan Chemical Industries is used instead of ST (4 parts by weight).

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 78 nm and 1.246, respectively. The reflectance at 550 nm was less than 0.3%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 160 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 3 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  In the preparation of the antireflection coating, instead of the silica sol solution (3 parts by weight), 3-mercaptopropyltriethoxysilane (S810 manufactured by Chisso) (0.1 part by weight) and a silicon oxide dispersion were added to IPA- An antireflection paint is prepared in the same manner as in Example 1, except that IPA-ST-UP (4 parts by weight) manufactured by Nissan Chemical Industries, Ltd. is used instead of ST (4 parts by weight).

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 82 nm and 1.252, respectively. The reflectance at 550 nm was less than 0.3%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 180 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  From this example and Examples 19 to 21, it was shown that a silicon compound having a hydrolyzable residue other than silica sol is also effective as a binder for forming this antireflection film.

  When preparing the anti-reflective coating, instead of the silica sol solution (3 parts by weight), titania sol solution (solid content 2.5%) (3 parts by weight) and silicon oxide dispersion were added to Nissan Chemical IPA-ST (4 parts by weight). The antireflection paint is prepared in the same manner as in Example 1 except that instead of IPA-ST-UP (4 parts by weight) manufactured by Nissan Chemical Co., Ltd.

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 80 nm and 1.263, respectively. The reflectance at 550 nm was 0.5%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 170 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  From this example, it was shown that a titanium compound is also effective in addition to the silicon compound as a binder for forming the antireflection film.

  When preparing the anti-reflective coating, the dispersion of silicon oxide was replaced with the dispersion of aluminum oxide (Alumina sol-520 manufactured by Nissan Chemical, solid content 20%) (4 parts by weight) instead of Nissan Chemical IPA-ST (4 parts by weight). An antireflection paint is prepared in the same manner as in Example 1, except that

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 102 nm and 1.315, respectively. The reflectance at 550 nm was 2.8%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 150 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 2 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  This example shows that inorganic oxides other than silicon oxide are also effective as the material of the inorganic oxide fine particles for forming this antireflection film.

  In the preparation of the antireflection coating, instead of the silica sol solution (3 parts by weight), an acrylic resin emulsion (Hitaloid SW6011, manufactured by Hitachi Chemical Co., Ltd., 50% solids) (0.15 parts by weight) was used. Instead of Nissan Chemical IPA-ST (4 parts by weight), Nissan Chemical Snowtex C (solid content 20%) (4 parts by weight) was used, and water (60 parts by weight) was used instead of ethanol (60 parts by weight). The antireflection paint is prepared in the same manner as in Example 1. In addition, the boiling point of the coating material of a present Example was 100 degreeC.

  Moreover, the glass plate which formed the anti-reflective film was produced like (1) of Example 1, and (3)-(5) except having changed the antireflective coating preparation and heating temperature into 120 degreeC. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 90 nm and 1.320, respectively. The reflectance at 550 nm was 2.9%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 80 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 8 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  From this example, it was shown that an organic polymer material such as an acrylic resin is also effective as a binder for forming the antireflection film in addition to an inorganic polymer material such as a silicon compound or a titanium compound. .

  When preparing the anti-reflective coating, a dispersion of silicon oxide was used instead of Nissan Chemical IPA-ST (4 parts by weight), Nissan Chemical IPA-ST-UP (2 parts by weight) and Nissan Chemical IPA-ST-ZL ( An antireflection paint is prepared in the same manner as in Example 1 except that 2 parts by weight) is used.

  Moreover, the glass plate in which the anti-reflective film was formed was produced similarly to (1) of Example 1, and (3)-(5) except preparation of the anti-reflective coating material. When the same evaluation test as (6) of Example 1 was performed, the film thickness and refractive index of the antireflection film formed on the glass plate were 102 nm and 1.250, respectively. The reflectance at 550 nm was 0.9%. When the cross section of the formed antireflection film was observed with a TEM, voids having a size of 5 to 150 nm were confirmed as shown in FIG.

When the surface resistivity of the formed antireflection film was measured, it was 4 × 10 ¹⁰ Ω under the conditions of a temperature of 20 ° C. and a humidity of 50%.

  This example shows that the inorganic oxide fine particles for forming the antireflection film are effective even if the particle shape and size are different.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Paint, 3 ... Bubble, 4 ... Air gap, 5, 9 ... Antireflection film of this invention, 6 ... Greenhouse in which antireflection film of this invention was formed, 7 ... Flower pot, 8 ... Tomato seedling, 10 DESCRIPTION OF SYMBOLS ... Polycarbonate board | substrate, 11 ... Protective layer, 12 ... Recording layer, 13 ... Monitor, 14 ... Spacer, 15 ... Acrylic board which formed antireflection film on both surfaces, 16, 20 ... Polarizing plate, 17 ... Image display part, 18 ... Acrylic plate, 19 ... Glass plate on which antireflection film is formed, 21 ... Operation part, 22 ... Glass substrate on which antireflection film is formed, 23 ... Surface electrode, 24 ... Upper photoelectric conversion layer, 25 ... Intermediate transparent electrode, 26 ... Lower photoelectric conversion layer, 27 ... back electrode.

Claims (13)

Inorganic oxide fine particles;
A binder,
A solvent,
An antireflection film formed on a substrate having a void,
The size of the void is 5 nm or more and 150 nm or less,
The film thickness of the antireflection film is 60 nm or more and 190 nm or less,
Regarding the antireflection film, the ratio of the voids increases from the substrate side toward the surface side of the antireflection film. Inorganic oxide fine particles;
A binder,
A solvent,
An antireflection film formed on a substrate having a void,
The size of the void is 5 nm or more and 150 nm or less,
The film thickness of the antireflection film is 60 nm or more and 190 nm or less,
About the antireflection film, the antireflection film having a tendency that the refractive index gradually decreases from the substrate side toward the surface side of the antireflection film. The antireflection film according to claim 1 or 2,
An antireflection film in which the substrate is a resin. The antireflection film according to claim 3,
The antireflection film is formed by heating,
The antireflection film wherein the heating temperature is higher than the boiling point of the solvent and 120 ° C. or lower. The antireflection film according to claim 1 or 2,
The antireflection film is formed by heating,
The antireflection film wherein the heating temperature is higher than the boiling point of the solvent and lower than a temperature 150 ° C. higher than the boiling point of the solvent. The antireflection film according to claim 1 or 2,
The anti-reflection film, wherein the binder is a silicon compound or a titanium compound. The antireflection film according to claim 1 or 2,
A layer made of a fluorine-containing compound on the surface of the antireflection film;
An antireflection film having a thickness of the layer made of the fluorine-containing compound of less than 56 nm. The antireflection film according to claim 7,
The said fluorine-containing compound is an antireflection film which is a compound shown below.

Here, X is a bonding site between the perfluoropolyether chain and the alkoxysilane residue, CONH- (CH ₂ ) ₃ ,
Y is a bonding site between a perfluoroalkyl group and an alkoxysilane residue, CONH- (CH ₂ ) ₃ , (CH ₂ ) ₂ ,
R is an alkyl group. Having one or more transparent walls,
A greenhouse in which the transparent wall surface is the antireflection film according to claim 1.   The board | substrate for indoor building materials which has an antireflection film of Claim 1 or 2. The antireflection film according to claim 1 or 2,
An optical recording medium having a recording layer.   An image display device comprising the antireflection film according to claim 1. The antireflection film according to claim 1 or 2,
A photovoltaic power generation module in which an electrode and a photoelectric conversion layer are formed under the antireflection film.

Images