JP2011028277A - Optical member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical member having an oxide layer with a stabilized micro uneven structure and excellent durability, and a method of manufacturing the optical member. <P>SOLUTION: The optical member has a base material 21 and an anti-reflection film on the surface of the base material. The anti-reflection film has a metal oxide layer having a micro uneven structure on the surface due to aluminum oxide crystals. The metal oxide layer contains an amorphous layer 23, and at least the surface of the metal oxide layer is aluminum phosphate 25. The height of the micro uneven structure is 0.1-5 μm. Alternately, the aluminum oxide crystals are boehmite. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical member. Specifically, the present invention relates to an optical member having a fine concavo-convex structure of an oxide on the surface.

  Glass glasses, optical lenses, solar battery panels, cathode ray tubes, filters, display panels, and the like are required to reduce surface light scattering and reflection. As one method for realizing this, a single-layer or multilayer antireflection film with a controlled refractive index and film thickness is used. In this case, it is known that the antireflection performance of the film changes depending on the wavelength and the incident angle, and it is known that it is difficult to realize high performance antireflection performance for a wide wavelength region and incident angle.

  On the other hand, it has been conventionally known that fine irregularities are formed on the surface of glass to provide an antireflection function. In particular, if miniaturization below the wavelength can be achieved, a high antireflection function is expected in a wide incident angle range. As means for miniaturization, chemical etching on the glass surface, mechanical roughing, and the like have been proposed. In chemical etching and mechanical processing, it is difficult to reduce the wavelength below the wavelength in the visible light range, and an antireflection performance has not yet been achieved in applications that require transparency. On the other hand, a coating film that forms an uneven structure on the surface of glass has also been studied. For example, Patent Document 1 discloses that individual leaflets having various heights and shapes are obtained by converting a metal film of aluminum, magnesium and zinc or an alloy thereof into an oxide or hydroxide into a transparent material including glass. A constructed anti-reflective coating is disclosed. Further, in Patent Document 2, a coating liquid composed of at least an aluminum alkoxide and a stabilizer is applied on a substrate, an amorphous alumina film is formed, then hydrothermally treated, dried and randomly assembled into a petal shape. An alumina membrane is disclosed.

Japanese Patent Publication No. 61-48124 JP-A-9-202649

  As shown in Patent Document 1 and Patent Document 2, the coating film is usually porous in many cases. Many high-refractive-index glasses that are base materials contain oxide components such as water, moisture-sensitive alkali metal oxides, alkaline earth metal oxides, and boron oxide. When these glasses are applied as a substrate for forming a coating film, water and moisture in the air enter the substrate surface, and alkali metal oxides, alkaline earth metal oxides and boron oxide contained in the substrate Etc. are released, and the surface or its interface becomes clouded or whitened. In particular, when an unstable component (for example, a water-soluble component or a component that can be dissolved and re-precipitated in water) contained in the porous oxide comes into contact with moisture, the hydration reaction proceeds and the optical characteristics are improved. Problems that change over time have also been pointed out. Furthermore, when placed in an environment containing an acid, the porous oxide itself may be dissolved by the acid or may be altered.

  The present invention has been made in view of such conventional problems, and relates to an optical member having a fine uneven structure on the surface of an oxide layer. In particular, an object of the present invention is to provide an optical member with an oxide layer that has a fine uneven structure on the surface of the oxide layer and is excellent in durability.

In order to achieve the above object, the optical member of the present invention is an optical member having a base material and an antireflection film on the surface of the base material, and the antireflection film is made of at least a surface of aluminum oxide crystals. It has a metal oxide layer in which a fine relief structure is formed, the metal oxide layer includes an amorphous layer, and at least the surface of the metal oxide layer is made of aluminum phosphate .

  According to the present invention, the stability of the fine uneven structure of the oxide layer is remarkably improved by providing the base material with an oxide layer having a fine uneven structure on the surface and further including a phosphate compound. Show the effect. Furthermore, it can be applied to optical glass containing alkali, alkaline earth, and boron, the weakness of durability derived from glass is eliminated, and an optical member having a wide range of optical characteristics becomes possible.

FIG. 1 illustrates a first embodiment of the optical member of the present invention. The second embodiment of the optical member of the present invention is illustrated.

(First embodiment)
FIG. 1 illustrates a first embodiment of the optical member of the present invention, which will be described below.

  This embodiment includes a base material 11 such as glass and an oxide layer 12 such as a composite of aluminum hydroxide oxide and aluminum oxide, and the oxide layer is formed on the surface of the optical member. The surface of the oxide layer 12 has a fine uneven structure, and the oxide layer further includes a phosphate compound-containing layer 13 containing a phosphate compound such as aluminum phosphate.

  The fine concavo-convex structure used in the present invention can be concavo-convex in the order of microns or submicrons, and is derived from a three-dimensional structure of a solid mainly composed of an oxide and voids. The form of the oxide may be crystalline or amorphous, and both crystalline and amorphous forms may exist. The fine uneven structure has a shape capable of continuously decreasing the refractive index toward the surface of the oxide layer (the surface of the oxide layer is the surface of the optical member and the interface with air). Yes. Accordingly, the reflection performance and transmission function of the surface of the optical member are controlled, and a matte function, an antireflection function, and the like are exhibited. When the fine uneven structure of the oxide layer is ordered, functions of reflection and transmission at a specific angle and a specific wavelength appear. In the case of the antireflection function, it is preferable that the fine concavo-convex structure on the surface is composed of anisotropic crystalline oxide fine particles. Examples of the shape of the anisotropic crystalline oxide fine particles include a plate shape and a needle shape. Specific examples of anisotropic crystalline oxide fine particles include oxides such as magnesium oxide, zinc oxide, titanium oxide, and aluminum oxide, hydroxides such as boehmite (aluminum hydroxide oxide), lithium silicate, and titanium silicate. And the like. In particular, plate-like particles that can easily form an inclined structure in the direction perpendicular to the surface are preferred. Specifically, plate-like boehmite particles obtained by a hydrothermal reaction are preferably used. By changing the size of the crystalline oxide fine particles and the size of the surface of the irregularities, an antireflection function for a wavelength corresponding to the size is realized. In the case of an antireflection film corresponding to visible light, the height of the unevenness is preferably 0.1 μm or more and 5 μm or less. If it is 0.1 μm or more, an antireflection function with visible light can be exhibited. On the other hand, when the height of the unevenness is 5 μm or less, the mechanical strength of the uneven structure can be kept high. The phosphate compound contributes to the stability of the oxide having a fine relief structure. By covering at least the surface of the oxide with the phosphate compound, the shape of the fine concavo-convex structure does not change with time and is stabilized. Moreover, a phosphate compound may intervene in the fine concavo-convex structure.

  In the absence of this phosphate compound, since the oxide layer is porous, water and moisture in the air enter the surface of the base material, and alkali metal oxide, alkali rare earth metal oxide contained in the base material, Boron oxide or the like is released, and the surface or its interface becomes cloudy. In addition, the reaction in the oxide layer may proceed, and characteristics such as the refractive index may change. The phosphate compound of the present invention suppresses the reactivity of unstable oxides such as amorphous oxides contained in the oxide layer, thereby suppressing changes in oxides caused by moisture in the air, Further, even under an acidic environment, oxide elution and deterioration, and collapse of the concavo-convex structure resulting from them do not occur. Furthermore, the surface of the anisotropic crystalline oxide fine particles forming the concavo-convex structure is also covered with the phosphate compound, whereby the acid resistance and durability of the concavo-convex structure are improved and the optical characteristics are stabilized.

  The phosphate compound used in the present invention is not particularly limited as long as it is insoluble in water. Specific examples include magnesium phosphate, calcium phosphate, zinc phosphate, barium phosphate, aluminum phosphate, gallium phosphate, lanthanum phosphate, titanium phosphate, and zirconium phosphate. When the durability of the substrate of the optical member as described above is low, it is preferable that a dense region is formed in the oxide layer by the phosphate compound.

  Examples of the substrate of the optical member of the present invention include glass and plastic. Typical plastic substrates include thermoplastics such as polyester, triacetyl cellulose, cellulose acetate, polyethylene terephthalate, polypropylene, polystyrene, polycarbonate, polymethyl methacrylate, ABS resin, polyphenylene oxide, polyurethane, polyethylene, and polyvinyl chloride. Resin films and molded articles; crosslinked polyester films, crosslinked molded articles obtained from various thermosetting resins such as unsaturated polyester resins, phenolic resins, crosslinked polyurethanes, crosslinked acrylic resins, crosslinked saturated polyester resins, etc. Can be mentioned.

  When an optical glass containing alkali, alkaline earth, or boron is used as a base material, if an oxide layer having a fine concavo-convex structure is provided on the surface, the oxide layer functions as an antireflection film having a high antireflection function. To do. Since a large number of glasses can be selected when the refractive index is in the range of 1.4 or more and 1.9 or less, a wide range of high-performance anti-reflection optical lenses are possible. If there is an oxide layer having a fine concavo-convex structure containing the phosphate compound of the present invention, deterioration due to a component having low water resistance is suppressed. Specific examples of the typical optical glass substrate include glass of barium flint, barium crown, cocoon crown, lanthanum flint, and lanthanum crown.

(Second Embodiment)
FIG. 2 illustrates a second embodiment of the optical member of the present invention, which will be described below.

  In the present embodiment, the description will focus on the differences from the configuration of the first embodiment.

  This embodiment includes a base material 21 such as glass and an oxide layer 24 such as aluminum hydroxide oxide, and the oxide layer is formed on the surface of the optical member. The surface of the oxide layer 24 has a fine uneven structure, and the oxide layer further includes a phosphate compound-containing layer 25 containing a phosphate compound. Further, the oxide layer includes an amorphous layer 23 having a thickness of 1 nm or more such as aluminum oxide, and a fine uneven structure is formed on the amorphous oxide layer 23. The term “amorphous” as used herein refers to a state in which diffraction derived from a crystal is not observed by the X-ray scattering and neutron scattering methods, and may be a continuous film by an ordinary observation method, or an aggregate of particles having a particle size of 50 nm or less. But it ’s okay.

The phosphate compound covers at least the surface of the oxide to form the phosphate compound layer 25. As will be described later, when the phosphoric acid compound penetrates into the gaps of the fine concavo-convex structure, the phosphate compound layer 25 is also formed on the armofus layer 23. Further, the entire alumofus layer may be changed to a phosphate compound layer. Moreover, the phosphate compound may intervene in the fine relief structure. This phosphate compound layer forms a dense layer. Furthermore, if necessary, for the purpose of improving the antireflection function, an intermediate layer 22 having a different refractive index may be provided on the surface of the substrate in advance. The intermediate layer is formed by a known method such as vapor deposition or sol-gel method, and specifically includes silica, titanium oxide, tin oxide, aluminum oxide, yttrium oxide, tantalum oxide, or a composite film thereof. I can do it. The refractive index _{n b} of the base material, the refractive index _{n s} of the intermediate layer, it is more effective if the refractive index _{n a} of the amorphous layer and _{n b} ≧ _{n s} ≧ _{n a.} By setting in this way, the refractive index can be gradually reduced from the base material to the amorphous oxide layer. Furthermore, since the refractive index can be continuously decreased from the amorphous layer toward the surface of the oxide layer by the fine concavo-convex structure, the antireflection effect can be remarkably enhanced.

  Next, the manufacturing method of the optical member of this invention is demonstrated. The optical member manufacturing method of the present invention includes a step of forming an oxide layer on a substrate, a step of forming a fine relief structure on the surface of the oxide layer, and an oxide layer having a fine relief structure on the surface. And a step of bringing a water-soluble phosphoric acid compound into contact therewith.

  After forming the precursor film | membrane used as an oxide layer on the surface of a base material, a fine uneven structure is formed in a precursor film | membrane. The method for forming the fine concavo-convex structure is not particularly limited, and examples thereof include methods such as phase separation, oxidation, phase transition, crystallization, and selective elution of the precursor film. Preferably, it is preferable to form anisotropic crystalline oxide particles from the step of bringing a metal film and a metal oxide film containing a metal species into contact with water.

  In the case of a metal film, when the metal film is brought into contact with water and oxidized into a particulate crystalline oxide or hydroxide, it is used to form the fine relief structure of the present invention. Examples of these metal species include aluminum, magnesium, zinc, and the like, and preferably aluminum. In the case of aluminum, plate-like boehmite crystalline particles having a size up to several hundred nm are formed. As the metal film, a film obtained by vapor deposition, ion plating, or sputtering is preferably used.

  Examples of the method for forming the metal oxide film include a sol-gel method, a sputtering method, and a vapor deposition method. When the metal oxide film is brought into contact with water, it crystallizes and fine irregularities are formed. Alternatively, the fine concavo-convex structure is also formed by selectively etching a part. The metal oxide film (hereinafter referred to as oxide film) is preferably amorphous, and when it comes into contact with water, elution and reprecipitation occur, and a fine uneven structure of crystalline fine particles is formed. Specific examples of the oxide include aluminum oxide, titanium oxide, and zinc oxide. If necessary, a composite film containing these as main components may be used, and an oxide component such as silica that does not grow by itself may be added as a solid solution component or a grain boundary component. When the surface of the oxide film is used as an antireflection film, an amorphous oxide mainly composed of aluminum oxide is preferably used. As the grain grows, the amorphous aluminum oxide oxide film transitions to a fine concavo-convex structure, but it is preferable that the Almophas precursor film (amorphous layer) remains with a thickness of 1 nm or more. As described above, the fine concavo-convex structure can continuously reduce the refractive index from the interface with the amorphous layer toward the surface of the oxide layer, thereby controlling the reflection performance and transmission function of the surface of the optical member. Develops a matte function, an antireflection function, and the like. Moreover, by leaving the amorphous layer, the phosphoric acid compound reacts with the alumofus layer, and a dense layer having excellent water resistance and acid resistance containing the phosphate compound is formed.

  The step of contacting with water may be basically performed under the condition of particle growth, and is preferably performed at a temperature of 50 ° C. or higher, more preferably 60 ° C. or higher. Although the time of a contact process is not specifically limited, Preferably it is 5 minutes or more and 3 hours or less.

  In the surface treatment step of bringing the oxide layer having a fine relief structure on the surface into contact with the water-soluble phosphate compound, the water-soluble phosphate compound reacts with at least a portion of the oxide, A phosphate compound is formed.

  The water-soluble phosphoric acid compound of the present invention may basically have a phosphate group and be water-soluble. Specific examples of the phosphoric acid compound include phosphoric acid, polyphosphoric acid, phosphoric acid amine salt, polyphosphoric acid amine salt, first phosphoric acid metal salt, and second phosphoric acid metal salt. These phosphoric acid compounds can be used alone or in combination of two or more thereof. When the reactivity of the phosphoric acid compound and the oxide layer having a fine concavo-convex structure is high, the reaction with the oxide component of the fine concavo-convex structure occurs rapidly, and the fine concavo-convex structure may be broken. In order not to impair the antireflection function derived from fine irregularities, the reactivity must be suppressed. As the phosphoric acid compound capable of suppressing the reactivity, a first metal phosphate metal salt and an amine phosphate salt are preferably used. Specific examples of the first metal phosphate include first calcium phosphate, first aluminum phosphate, first zinc phosphate, and first titanium phosphate. In the case of phosphoric acid amines, mention may be made of phosphoric acid amine salts such as primary, secondary and tertiary ammonium phosphates, phosphoric acid methylamine salts, phosphoric acid ethylamine salts, and phosphoric acid alkanolamine salts. By using such a phosphoric acid compound in the form of a metal salt, the reaction between the phosphoric acid group and the oxide layer having a fine concavo-convex structure occurs more gently. In the case of using an amine phosphate, the reactivity between the amine phosphate and the oxide layer having a fine relief structure is reduced by the amine. In the contacting step, the function as a phosphoric acid group is expressed as the amine is released, and the reaction with the oxide layer having a fine concavo-convex structure proceeds. By such a reaction between the phosphoric acid compound and the oxide layer having a fine relief structure, a layer made of a water-insoluble metal phosphate is formed on the surface of the oxide component having the fine relief structure.

  A water-soluble phosphoric acid compound is used, and an aqueous dispersion or a dispersion of a water-soluble organic solvent such as alcohol is used. The water-soluble phosphate compound is more preferably in the form of an aqueous dispersion, and the content of the phosphate compound in the dispersion is 0.01 wt% or more and 30 wt% or less, more preferably 0.8. It is 05 weight% or more and 20 weight% or less. When the content is 0.01% by weight or more, the effect of the phosphate compound in the oxide layer having a fine concavo-convex structure can be expressed. On the other hand, when the phosphoric acid compound is 30% by weight or less, the fine concavo-convex structure is maintained, and the optical characteristics derived from the fine concavo-convex structure are not impaired.

  As a method of contacting with a water-soluble phosphate compound, a method of immersing a substrate having an oxide layer having a fine concavo-convex structure in a water-soluble phosphate compound dispersion in a water-soluble phosphate compound dispersion, Examples of the application method include dip, spin and spray. When applying more phosphoric acid-based compounds to the oxide layer with fine concavo-convex structure, use a dispersion medium such as water or alcohol, and use a method such as washing or pouring to remove it. Good.

  More specifically, when the fine concave structure is an anisotropic oxide particle layer, the phosphorylated compound reacts with the anisotropic oxide particle, and a water-insoluble phosphate compound film is formed on the particle surface. It is formed. In the region where the particle size is 100 nm or less and the particle density is large, a dense phosphate compound region is formed. Furthermore, when the said oxide layer has the said Almophas layer, a phosphoric acid type compound reacts with an Almophas layer, and it is excellent in water resistance containing a phosphate compound, and a precise | minute layer is formed. In this case, even if the base material is transparent glass containing any element of alkali, alkaline earth, and boron, which is sensitive to moisture, the penetration of moisture into the glass is suppressed, and it is durable in a high-temperature and high-humidity environment. An optical member having excellent properties can be obtained.

  When it is necessary to promote the reaction between the phosphoric acid compound and the oxide component having a fine concavo-convex structure, after bringing the phosphoric acid compound into contact, a drying step of 300 ° C. or less may be performed.

  Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to such examples.

  The fine unevenness on the surface obtained in each Example and Comparative Example was evaluated by the following method. As an evaluation of the fine concavo-convex structure, the cross section of the sample was observed using a scanning electron microscope (FE-SEM, S4500, manufactured by Hitachi, Ltd.). Moreover, in order to evaluate a cloudiness degree, the haze value which is a general numerical value which judges a cloudiness condition was measured using the haze meter (Nippon Denshoku, NDH2000).

  Regarding the stability of the fine concavo-convex structure, after being continuously exposed for 1000 hours with a circulating high-temperature and high-humidity machine at 60 ° C. and a relative humidity of 90%, the cross section or cloudiness was evaluated again. Further, as an acid-resistant characteristic, it was immersed in 0.01 N hydrochloric acid, and a change in the appearance of the fine concavo-convex structure was observed.

Example 1
A coating solution for an amorphous aluminum oxide film by a sol-gel method is prepared. Specifically, aluminum-sec-butoxide [Al (O-sec-Bu) ₃ ] is dissolved in 2-propanol [IPA] with stirring, ethyl acetoacetate [Eacac] is added as a stabilizing component, and adjusted. A coating solution was prepared. Here, the molar ratio of the coating liquid was Al (O-sec-Bu) ₃ : IPA: Eacac = 1: 20: 1. After stirring for 30 minutes, the hydrolyzed H ₂ O and catalyst components were added so that H ₂ O: Al (O-sec-Bu) ₃ = 1: 1 and 0.01 M hydrochloric acid. The obtained mixed solution was reacted for 48 hours to obtain an amorphous aluminum oxide coating solution.

As a phosphoric acid compound treatment solution, 1 part by weight of primary aluminum phosphate [Al (H ₂ PO ₄ ) ₃ ] was dissolved in 200 parts by weight of pure water and allowed to stand for about 2 days. Thereafter, it was passed through a 0.1 μm filter. The obtained transparent liquid was designated as a treatment liquid 1 for a phosphoric acid compound.

  Three silica glass substrates having a thickness of 1 mm were prepared, immersed in a coating solution, and coated by a dipping method under conditions of a pulling rate of 3 mm / s and a relative humidity of 50%. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain silica glass with an amorphous aluminum oxide layer. The obtained silica glass was treated with warm water to make the aluminum oxide fine uneven. Each was placed in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. Two of them were immersed in the phosphoric acid compound treatment solution 1 and pulled up at a lifting speed of 3 mm / s. Then, it heat-processed for 1 hour with the dryer of 60 degreeC, and obtained the silica glass with the oxide layer of a fine concavo-convex structure. One of them was stored in a vacuum desiccator, and the other was subjected to a durability test under the above-described durability test conditions (60 ° C., relative humidity 90%).

  When the sample subjected to the durability test and the sample stored in the vacuum desiccator were evaluated with a spectrophotometer, the transmittance was 99.6% at 500 nm, and the appearance was not changed. Further, when the surface of the fine concavo-convex structure was observed, it was found that all of the rugged structure was a concavo-convex structure layer composed of a 70 nm Almophas layer and a plate-like particle having a thickness of about 350 nm. Compared to the sample stored in a vacuum desiccator, it did not change under high temperature and high humidity conditions. As an acid resistance evaluation, this sample was immersed in a 0.01N hydrochloric acid aqueous solution for 15 minutes. Thereafter, it was rinsed with distilled water, dried at 80 ° C. and observed, and no change in appearance and transmittance due to immersion in hydrochloric acid was observed.

(Comparative Example 1)
Using the uncoated sample of the first aluminum phosphate of Example 1, a durability experiment was conducted in the same manner as in Example 1. The appearance was not different from the vacuum storage sample of Example 1. On the other hand, when the cross section was observed with an electron microscope, it was confirmed that the amorphous layer was 50 nm. Unlike the first aluminum phosphate coating sample, it was found that the amorphous layer was unstable and unstable in a high-temperature and high-humidity environment. Thereafter, in the same manner as in Example 1, this sample was immersed in 0.01N hydrochloric acid and evaluated for acid resistance. As a result, the aluminum oxide film on the surface disappeared completely and there was no acid resistance.

(Example 2)
_Two soda-lime silica glasses (Na ₂ O: 17 wt%) having a thickness of 1 mm were applied to the alumofas aluminum oxide coating solution of Example 1 under the conditions of a pulling rate of 3 mm / s and a relative humidity of 50% by dipping. Coated. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water to make aluminum oxide fine unevenness. Each was placed in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. One of them was immersed in the phosphoric acid compound treatment solution 1 and pulled up at a lifting speed of 3 mm / s. Then, it heat-processed for 1 hour with the 60 degreeC drying machine, and obtained the glass 2. FIG.

  When the durability test was performed under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 99.7%. When measured with a haze meter (Nippon Denshoku, NDH2000), the haze value was 0.12, and there was no change compared to the measured value before the durability test. Finally, a cross-sectional observation of the sample with an electron microscope reveals that the layer has a concavo-convex structure composed of a 30-nm Almophas layer and a plate-like particle having a thickness of about 320 nm, and there is no change compared to the measured value before the durability test. I understood it.

(Comparative Example 2)
The durability test was performed on the glass of the fine uneven structure untreated with the first aluminum phosphate of Example 2 and the untreated soda lime silica glass. All became cloudy. When measured with a haze meter, the haze values were 2 and 2.5, respectively.

(Example 3)
As a processing solution for a phosphoric acid compound, 1 part by weight of ammonium phosphate [(NH ₄ ) ₃ PO ₄ ] was dissolved in 200 parts by weight of pure water, and left standing for about 2 days. The obtained transparent liquid was used as the phosphoric acid compound treatment liquid 2.

_Two glasses with 11% Na ₂ O and an optical glass having a refractive index of 1.81 as a base material and a vacuum deposited tungsten film using a tungsten heater were prepared. Each of the obtained glasses was put in a stainless steel holder, immersed in boiling water for 1 hour, and then heat treated with a dryer at 100 ° C. for 1 hour. One of them was immersed in the phosphoric acid compound treatment solution 2 and pulled up at a lifting speed of 3 mm / s. Then, it heat-processed for 1 hour with the dryer of 60 degreeC, and obtained the glass 3.

  When the durability test was performed on the glass 3 under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 98.4%. When measured with a haze meter, the haze value was 0.11, and there was no change compared to the measured value before the durability test. Finally, when the cross section of the sample was observed with an electron microscope, it was found that the layer was a concavo-convex structure layer of plate-like particles having a thickness of about 155 nm, and there was no change compared to the measured value before the durability test.

(Comparative Example 3)
When the above-mentioned durability test was performed on the glass not treated with ammonium phosphate of Example 3, the glass became cloudy. When measured with a haze meter, the haze value was 1.2.

Example 4
Two sheets of optical borosilicate glass (Na ₂ O: 9 wt%, K ₂ O: 9 wt%) having a thickness of 1 mm and a refractive index of 1.58 were coated with the Almophas aluminum oxide coating solution of Example 1. The coating was performed by a dipping method under conditions of a lifting speed of 3 mm / s and a relative humidity of 50%. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water to make aluminum oxide fine unevenness. Each was placed in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. One of them was immersed in the phosphoric acid compound treatment solution 1 and pulled up at a lifting speed of 3 mm / s. Then, it heat-processed for 1 hour with the 60 degreeC drying machine, and obtained the glass 4. FIG.

  When the durability test was performed under the above durability test conditions, the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 99.6%. When measured with a haze meter, the haze value was 0.09 and there was no change compared to the measured value before the durability test. Finally, a cross-sectional observation of the sample with an electron microscope reveals that the layer has a concavo-convex structure composed of a 27 nm amorphous layer and a plate-like particle having a thickness of about 370 nm, and there is no change compared to the measured value before the durability test. I understood it.

(Example 5)
As a phosphoric acid compound treatment solution, 1 part by weight of primary calcium phosphate [Ca (H ₂ PO ₄ ) ₂ H ₂ O] was dissolved in 100 parts by weight of pure water and allowed to stand for about 2 days. The obtained transparent liquid was designated as a treatment liquid 3 for a phosphoric acid compound.

One sheet of soda lime silica glass (Na ₂ O: 17 wt%) having a thickness of 1 mm was applied to the Almophas aluminum oxide coating solution of Example 1 by the dipping method under the conditions of a pulling rate of 3 mm / s and a relative humidity of 50%. Coated. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water to make aluminum oxide fine unevenness. Each was placed in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. Then, it was immersed in the processing liquid 3 of a phosphoric acid type compound, and it pulled up with the pulling-up speed of 3 mm / s. Then, it heat-processed for 1 hour with the 60 degreeC drying machine, and obtained the glass 5. FIG.

  When the durability test was performed on the glass 5 under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 98.2%. When measured with a haze meter, the haze value was 0.10. Finally, a cross-sectional observation of the sample with an electron microscope revealed that the layer had a concavo-convex structure composed of a 15 nm Almorphus layer and a plate-like particle having a thickness of about 390 nm.

  The phosphoric acid compound treatment liquid contains calcium which is an alkaline earth metal. However, it differs from the form of alkaline earth metal contained in the substrate. When the substrate with an aluminum oxide layer is immersed in the phosphoric acid compound treatment liquid, the phosphoric acid compound reacts with the aluminum oxide component to form a water-insoluble composite layer containing calcium phosphate and aluminum phosphate. This layer prevents moisture from penetrating the base glass, and calcium itself is firmly bonded in the form of phosphate and cannot move, so the optical properties change due to the movement of calcium in the aluminum oxide layer. Does not happen.

(Example 6)
A 0.5% first zinc phosphate [Zn (H ₂ PO ₄ ) ₂ ] aqueous solution was used as a treatment liquid for the phosphoric acid compound (treatment liquid 4). Here, used was dissolved first zinc phosphate 1 part by weight _[Zn (H _{2 PO 4)} 2] in pure water 200 parts by weight.

One sheet of soda lime silica glass (Na ₂ O: 17 wt%) having a thickness of 1 mm was applied to the Almophas aluminum oxide coating solution of Example 1 by the dipping method under the conditions of a pulling rate of 3 mm / s and a relative humidity of 50%. Coated. Then, it dried in the air for 30 minutes and heat-processed for 1 hour with the dryer of 300 degreeC. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water to make aluminum oxide fine unevenness. Each was placed in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. Then, it was immersed in the processing liquid 4 of a phosphoric acid type compound, and it pulled up with the pulling-up speed of 3 mm / s. Then, it heat-processed for 1 hour with the 60 degreeC drying machine, and obtained the glass 6. FIG.

  When the durability test was performed on the glass 6 under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 98.5%. When measured with a haze meter, the haze value was 0.11. Finally, a cross-sectional observation of the sample with an electron microscope revealed that the layer had a concavo-convex structure composed of an Almofus layer having a thickness of 35 nm and plate-like particles having a thickness of about 400 nm.

(Example 7)
An optical glass having a thickness of 1 mm, containing 11 wt% Na ₂ O, and a refractive index of 1.81 was used as a base material.

Tetraethoxysilane (TEOS) was dissolved in ethanol (EtOH), and 0.01 M HCl aqueous solution was added as a catalyst, followed by stirring for 6 hours. The molar ratio of each component at this time was TEOS: EtOH: HCl (aq) = 1: 40: 2. Further, after dissolving titanium n-butoxide (TBOT) in ethanol, ethyl acetoacetate (EAcAc) was added as a stabilizing component, and the mixture was stirred at room temperature for 3 hours. The molar ratio of each component was TBOT: EtOH: EAcAc = 1: 20: 1. The _SiO in a molar ratio of the TiO ₂ sol solution was added to the SiO ₂ sol solution _2: TiO 2 = 70: 30 and so as added, the mixture was stirred at room temperature for 2 hours _to obtain a coating solution of SiO 2 -TiO ₂ intermediate film.

  The glass substrate was immersed in an intermediate film coating solution, and a coating film was formed on the surface of the glass substrate by a dipping method under a pulling rate of 2 mm / second and a relative humidity of 50%. After drying, heat treatment was performed by baking at 300 ° C. for 1 hour, and an amorphous oxide intermediate film containing transparent Ti and Si was coated.

  The glass substrate provided with the intermediate film was coated on the Almophas aluminum oxide coating solution of Example 1 by dipping method under the conditions of a lifting speed of 3 mm / s and a relative humidity of 50%. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water, and a part of the aluminum oxide layer was converted into boehmite to make fine irregularities. The sample was put in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. Then, it was immersed in the treatment liquid 1 of the phosphoric acid compound of Example 1 and pulled up at a lifting speed of 3 mm / s. Finally, heat treatment was performed for 1 hour with a dryer at 60 ° C. to obtain glass 7.

  When the durability test was performed on the glass 7 under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 99.5%. When measured with a haze meter, the haze value was 0.11.

(Example 8)
An optical glass containing 30 wt% B ₂ O ₃ and having a refractive index of 1.77 was used as a base material.

First, Example 7 of SiO _{2 SiO} in a molar ratio of the TiO ₂ sol solution was added to the sol solution _2: TiO 2 = 80: 20 and so as added, the mixture was stirred at room temperature for 2 _hours, the SiO 2 -TiO ₂ intermediate film A coating solution was prepared. A coating film was formed on the surface of the glass substrate by a dipping method using an intermediate film coating solution under the conditions of a pulling rate of 2 mm / second and a relative humidity of 60%. After drying at room temperature, heat treatment was performed at 300 ° C. for 1 hour to obtain a glass with a transparent amorphous SiO ₂ —TiO ₂ film.

  The obtained substrate with an intermediate film was coated on the Almophas aluminum oxide coating solution of Example 1 by dipping method under the conditions of a lifting speed of 3 mm / s and a relative humidity of 50%. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water to make aluminum oxide fine unevenness. The sample was put in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. Then, it was immersed in the process liquid 1 of a phosphoric acid type compound, and it pulled up with the pulling-up speed of 3 mm / s. Finally, the glass 8 was heat-treated for 1 hour with a dryer at 60 ° C.

  When the durability test was performed on the glass 8 under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 99.4%. When measured with a haze meter, the haze value was 0.09.

Example 9
An optical glass containing 7 wt% Na ₂ O and having a refractive index of 1.65 was used as a base material.

First, Example 7 of SiO _{2 SiO} in a molar ratio of the TiO ₂ sol solution was added to the sol solution _2: TiO 2 = 80: 20 and so as added, the mixture was stirred at room temperature for 2 _hours, the SiO 2 -TiO ₂ intermediate film A coating solution was prepared. A coating film was formed on the surface of the glass substrate by a dipping method using an intermediate film coating solution under the conditions of a pulling rate of 1.5 mm / second and a relative humidity of 60%. After drying at room temperature, heat treatment was performed at 300 ° C. for 1 hour to obtain a glass with a transparent amorphous SiO ₂ —TiO ₂ film.

  The obtained substrate with an intermediate film was coated on the Almophas aluminum oxide coating solution of Example 1 by dipping method under the conditions of a lifting speed of 3 mm / s and a relative humidity of 50%. Thereafter, it was dried in air for 30 minutes, and then heat-treated with a dryer at 300 ° C. for 1 hour. Thereafter, coating was repeated twice to obtain a glass substrate with an amorphous aluminum oxide layer. The obtained glass substrate was treated with warm water to make aluminum oxide fine unevenness. The sample was put in a stainless steel holder, immersed in pure water at 80 ° C. for 30 minutes, and then dried with a dryer at 100 ° C. Then, it was immersed in the process liquid 1 of a phosphoric acid type compound, and it pulled up with the pulling-up speed of 3 mm / s. Finally, heat treatment was performed for 1 hour with a dryer at 60 ° C. to obtain glass 9.

  When the durability test was performed on the glass 9 under the above-described durability test conditions (60 ° C., relative humidity 90%), the appearance did not change. When the transmittance was measured with a spectrophotometer, the transmittance was 99.6%. When measured with a haze meter, the haze value was 0.10.

11, 21 Base material 12, 24 Oxide layer 13, 25 Phosphate compound-containing layer 22 Intermediate layer 23 Amorphous layer

Claims (3)

An optical member having a base material and an antireflection film on the surface of the base material, wherein the antireflection film has at least a metal oxide layer having a fine concavo-convex structure formed of aluminum oxide crystals on the surface, The optical member, wherein the metal oxide layer includes an amorphous layer, and at least a surface of the metal oxide layer is made of aluminum phosphate .   The optical member according to claim 1, wherein a height of the fine concavo-convex structure is 0.1 μm or more and 5 μm or less. The optical member according to claim 1, wherein the aluminum oxide crystal is boehmite.

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