JP2004250321A - Inorganic porous thin film, laminate using it, and method of manufacturing inorganic porous thin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic porous thin film in which many pores with a specified shape are arranged in a single layer with a specified pattern; a laminate using it; and a method of manufacturing the inorganic thin film. <P>SOLUTION: The inorganic thin film 10 has many pores 5 with almost circular openings 1 and almost spherical inner surfaces 3, the pores 5 being arranged in a single layer along the plane of the thin film 10. The average diameter d1 of the openings 1 is 30-3,000 nm, and the average distance d2 between the centers of the neighboring openings 1 is 100-230% of the average diameter d1. The thickness d3 of the thin film is 30-100% of the average diameter d1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an inorganic porous thin film, a laminate using the same, and a method for producing an inorganic porous thin film.

  Self-organization is one of the bottom-up pattern formation methods, and is a powerful method for realizing mass production using nanotechnology.

In recent years, research on a three-dimensional structure in which pores are formed using an organic / inorganic mixed particle system has been advanced. As such research, research which synthesizes porous silica particles by spray drying using a mixed aqueous solution of colloidal silica particles (5 nm) and polystyrene particles (100 nm to 200 nm) (for example, see Non-Patent Documents 1 and 2), Research to produce an inorganic porous thin film with a three-dimensional periodic structure by vertically placing a glass substrate in a mixed aqueous solution of nanoparticles such as silica and polystyrene particles and pulling it up at a rate of 2 mm per minute (vertical deposition method) Non-Patent Documents 3 to 5) are known.
Iskandar, F .; Mikrajuddin; Okuyama, K .; "In Situ Production of Spherical Silica Particles Containing Self-Organized Mesopores", Nano Lett. (Communication); 2001; 1 (5); p.231-234. Iskandar, F .; Mikrajuddin; Okuyama, K .; "Controllability of Pore Size and Porosity on Self-Organized Porous Silica Particles""Nano Lett. (Communication); 2002; 2 (4); p.389-392 ZZ Gu, S. Kubo, A. Fujisima, O. Sato; "Infiltration of colloidal crystal with nanoparticles using capillary forces: a simple technique for the fabrication of films with an ordered porous structure"; Appl. Phys. A; 2002; 74 ; p.127-129 Kei Tadazawa, Osamu Sato, Akira Fujishima; Preparation of Oxide Reverse Opal Film, MATERIAL STAGE, 2002, Vol. 2, No. 5 Orlin D. Velev and Eric W. Kaler; "Structured Porous Materialsvia Colloidal Crystal Templating: From Inorganic Oxides to Metals"; Adv. Mater; 2000, 12, No.7; p.531-534

  However, when an inorganic porous thin film is produced by the vertical deposition method described in the above publication, the resulting inorganic porous thin film has a large number of holes arranged in a multilayer structure with a three-dimensional periodic structure. A pattern arranged in one layer was not obtained.

  Accordingly, an object of the present invention is to provide an inorganic porous thin film in which a large number of holes having a predetermined shape are arranged in one layer in a predetermined pattern, a laminate using the same, and a method for producing the inorganic porous thin film.

  In the coating process in the production of the inorganic porous thin film, the inventors of the present invention include a sol-like form containing inorganic ultrafine particles and organic fine particles having a predetermined particle size as solid components and having a total solid content concentration within a predetermined range. By using the coating liquid, it has been found that an inorganic porous thin film in which a large number of holes having a predetermined shape are arranged in one layer in a predetermined pattern is obtained, and the present invention has been completed.

  That is, the inorganic porous thin film of the present invention is an inorganic porous thin film having a large number of holes having an opening having a substantially circular shape and an inner peripheral surface of a substantially spherical shape. Arranged in layers, the average diameter of the openings is 30 to 3000 nm, the average distance between the centers of the adjacent openings is 100 to 230% of the average diameter of the openings, and the film The thickness is 30 to 100% of the average diameter of the opening.

  Such an inorganic porous thin film has a large number of holes of a predetermined shape arranged in one layer in a predetermined pattern, so that a photonic crystal, a low reflection treatment (for example, a low reflection treatment film) on a glass surface, a carbon nanotube, It is particularly suitable as a field emitter template.

  In the inorganic porous thin film, the openings are arranged in a hexagonal symmetry (arranged in a hexagonal symmetrical network), and / or the average depth of the holes is 50 to 100% of the film thickness. It is preferable.

  Moreover, the laminated body of this invention is equipped with a board | substrate and the inorganic porous thin film of the said this invention formed on the at least one surface of this board | substrate, It is characterized by the above-mentioned.

  The present invention is also a sol-like coating liquid in which inorganic ultrafine particles having an average particle diameter of 3 to 50 nm and organic fine particles having an average particle diameter of 30 to 3000 nm are dispersed in a dispersion medium (provided that the organic fine particles are inorganic ultrafine particles). Coating having an average particle size larger than that of the fine particles), a total solid content concentration of 0.1 to 20% by mass, and a content of the organic fine particles of 20 to 1000 parts by mass with respect to 100 parts by mass of the inorganic ultrafine particles. By supplying a working liquid onto the substrate and removing at least a part of the dispersion medium from the supplied coating liquid (preferably removing all of the dispersion medium), the organic fine particles are formed on the substrate. Coating step for forming a gel-like thin film in which the above-mentioned inorganic ultrafine particles are arranged between the organic fine particles and an inorganic porous thin film by removing the organic fine particles by firing the obtained gel-like thin film Get baked It provides a method of producing an inorganic porous film which comprises a step. By this production method, the inorganic porous thin film of the present invention can be obtained.

  In this production method, the inorganic ultrafine particles are preferably made of silica, and / or the organic fine particles are preferably made of a polymer.

  In this production method, the supply means for supplying the coating liquid in the coating step is preferably a spin coater, a gravure coater or a die coater, and the supply means is a spin coater, More preferably, the maximum rotational speed is 1000 to 8000 rpm, or the supply means is a gravure coater or a die coater, and the film formation speed during coating is 1 to 1000 m / s.

  Furthermore, in the method for producing an inorganic porous thin film of the present invention, in the baking step, the melting point or glass transition temperature of the inorganic ultrafine particles or higher (the inorganic ultrafine particles have a melting point and a glass transition temperature). It is preferable to obtain the inorganic porous thin film by firing the gel-like thin film at a lower temperature) or lower.

  According to the present invention, it is possible to obtain an inorganic porous thin film in which a large number of holes having a predetermined shape are arranged in a single layer in a predetermined pattern, and a laminate using the same, and a method for producing the inorganic porous thin film is provided. It becomes possible to provide. Such an inorganic porous thin film is particularly suitable as a photonic crystal, a low reflection treatment on the glass surface, and a template for a carbon nanotube field emitter.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted. Moreover, the dimension in drawing does not necessarily correspond with an actual dimension.

(Inorganic porous thin film, laminate using the same)
FIG. 1 is a perspective view of a “laminated body in which an inorganic porous thin film is formed on a substrate” according to the embodiment, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  First, the inorganic porous thin film 10 will be described. The inorganic porous thin film 10 shown in FIGS. 1 and 2 is formed on a substrate 20. The inorganic porous thin film 10 is an inorganic porous thin film 10 having a large number of holes 5 in which the opening 1 has a substantially circular shape and the inner peripheral surface 3 has a substantially spherical shape, and the holes 5 are planes of the inorganic porous thin film 10. The average diameter d1 of the openings 1 is 30 to 3000 nm, and the average distance d2 between the centers of the adjacent openings 1 is 100 to 230% of the average diameter d1 of the openings 1. And the film thickness d3 is 30 to 100% of the average diameter d1 of the openings 1.

  Although the inorganic porous thin film 10 can be produced by a method for producing an inorganic porous thin film, which will be described later, inorganic ultrafine particles are used as the raw material. Such inorganic ultrafine particles include metals such as gold, silver, copper, iron, aluminum, titanium and nickel; silica (silicon dioxide), alumina (aluminum oxide), titania (titanium oxide), iron oxide, zinc oxide, It is preferably at least one of inorganic oxides such as nickel oxide, niobium oxide and cerium oxide, or inorganic nitrides such as silicon nitride, aluminum nitride and titanium nitride. Among the fine particles made of such a material, inorganic ultra fine particles made of an inorganic oxide are preferable, and inorganic ultra fine particles made of silica are more preferable.

  The average particle size of the inorganic ultrafine particles is preferably 3 to 50 nm, more preferably 3 to 20 nm, still more preferably 3 to 15 nm, and particularly preferably 3 to 10 nm. If the average particle size of the inorganic ultrafine particles is less than 3 nm, it is difficult to produce the inorganic ultrafine particles, so that it is difficult to produce the inorganic porous thin film, and if it exceeds 50 nm, it is difficult to form the pores 5 having the above shape. This makes it difficult to produce an inorganic porous thin film.

  The average particle diameter of the inorganic ultrafine particles can be determined by a transmission electron microscope (TEM) method. In addition, the inorganic porous thin film 10 is preferably substantially composed of the above-described raw materials and inorganic materials that are constituents thereof, but may contain less than 10% organic material.

  As described above, the shape of the hole 5 in the inorganic porous thin film 10 is such that the opening 1 is substantially circular and the inner peripheral surface 3 is substantially spherical. In such a shape, substantially spherical organic fine particles are dispersed at a predetermined interval in a precursor of an inorganic porous thin film (gel thin film in the method for producing an inorganic porous thin film of the present invention) at a predetermined interval. The organic fine particles can be formed by removing by baking. In addition, the opening part 1 is a substantially circular edge part of the hole 5 in the inorganic porous thin film 10 surface, as shown in FIG.

  The average diameter d1 of the opening 1 is 30 to 3000 nm, preferably 40 to 1700 nm, and more preferably 100 to 1000 nm. The average diameter d1 basically corresponds to the average particle diameter of the organic fine particles serving as a template for the holes 5 and firing is performed in a state where the organic fine particles are arranged in a line. It is possible to obtain an inorganic porous thin film arranged in the form (FIG. 2).

  Moreover, as for the inorganic porous thin film 10, the average distance d2 between the centers of the adjacent openings 1 is 100 to 230% of the average diameter d1 of the openings 1, and is 100 to 180%. Is more preferable, and the length is further preferably 120 to 160%. When the average distance d2 is less than 100%, the adjacent portions of the hole and the adjacent hole are connected. On the other hand, if the average distance d2 is longer than 230% of the average diameter d1, the arrangement of the openings 1 becomes irregular.

  Here, the center of the opening 1 means the center when the outline of the opening 1 is a perfect circle. Further, when the contour of the opening 1 is a shape deformed from a perfect circle, the center of the opening 1 is the center of gravity of the shape (when assuming a plate-like body having the same contour as the opening 1 and a uniform density) The position corresponding to the center of gravity of the plate-like body.

  The openings 1 are preferably arranged in hexagonal symmetry. FIG. 3 is a schematic view of the inorganic porous thin film 10 in which the openings 1 are arranged in a hexagonal symmetry (corresponding to a top view of the laminate of FIG. 1). As shown in FIG. 3, when the openings are arranged in a hexagonal symmetry, when any one opening is selected, the six openings are hexagonal (preferably a regular hexagon is centered on the opening. ) State (so-called hexagonal periodic structure).

  The inorganic porous thin film 10 has a thickness d3 of 30 to 100% of the average diameter d1 of the openings 1 and preferably 50 to 80% of the average diameter d1. If the film thickness d3 is less than 30% of the average diameter d1, the film does not serve as a hole, and if it is more than 100% of the average diameter d1, there is a possibility that a large crack will occur in the thin film. .

  The average pore depth d4 in the inorganic porous thin film 10 is preferably 50 to 100% of the film thickness d3, and more preferably 70 to 100% of the film thickness d3. If the average depth d4 of the holes is less than 50% of the film thickness d3, it becomes one of the factors that cause cracks in the thin film.

  FIG. 4 is a cross-sectional view of the laminate when the average hole depth d4 is 100% of the film thickness d3, that is, when the average hole depth d4 is equal to the film thickness d3 (d3 = d4). In this case, the holes 5 in the inorganic porous thin film 10 are through holes. Moreover, when the laminated body 100 is seen from the direction in which the inorganic porous thin film 10 is formed, it can be seen in a state where a part of the substrate 20 is exposed.

  In addition, after forming the inorganic porous thin film 10 on the board | substrate 20, it isolate | separates or peels from the board | substrate 20, and can use the inorganic porous thin film 10 alone.

  Next, a laminated body is demonstrated. A laminated body 100 according to the embodiment shown in FIGS. 1 and 2 includes a substrate 20 and the inorganic porous thin film 10 formed on at least one surface of the substrate 20. .

  As the substrate 20 in the stacked body 100, a flat substrate made of glass, quartz, silicon, aluminum, or the like can be used. The shape of such a substrate is not particularly limited, but a substrate having a disk shape and a diameter of 10 to 90 mm and a thickness of 0.2 to 3.0 mm is preferable.

  The inorganic porous thin film 10 and the laminate 100 using the inorganic porous thin film 10 described above are particularly suitable for photonic crystals, low reflection treatment of glass surfaces, carbon nanotube field emitter templates, and the like.

(Inorganic porous thin film manufacturing method)
Hereinafter, the manufacturing method of an inorganic porous thin film is demonstrated.

  The inorganic porous thin film and the laminate described above can be obtained by the following method for manufacturing an inorganic porous thin film according to the embodiment. That is, 20 to 1000 parts by mass of organic fine particles having an average particle size of 30 to 3000 nm with respect to 100 parts by mass of inorganic ultrafine particles having a total solid content concentration of 0.1 to 20% by mass and an average particle size of 3 to 50 nm. The sol-like coating liquid contained is applied onto a substrate and dried, and includes the organic fine particles arranged in a single layer in the plane direction on the substrate and the inorganic ultrafine particles present between the organic fine particles. It can be produced by a method including a coating step for obtaining a gel-like thin film and a firing step for removing the organic fine particles by firing the obtained gel-like thin film to obtain an inorganic porous thin film. However, the organic fine particles need to have a larger average particle size than the inorganic ultra fine particles.

  First, the sol-like coating liquid used in this production method will be described. The sol-like coating liquid contains inorganic ultrafine particles and organic fine particles as a solid content, and the total solid content concentration in the sol-shaped coating liquid is 0.1 to 20% by mass, more preferably 0. It is 2-10 mass%, More preferably, it is 0.5-10 mass%. If the total solid content concentration is less than 0.1% by mass, it is difficult to produce an inorganic porous thin film because the concentration is too low. If the total solid content concentration exceeds 20% by mass, organic fine particles are arranged in multiple layers. Production becomes difficult.

  As the inorganic ultrafine particles, those similar to the inorganic ultrafine particles described in the description of the inorganic porous thin film can be used.

  The organic fine particles are preferably composed of polymers such as polystyrene, styrene-butadiene copolymer, polyvinyltoluene, styrene-divinylbenzene copolymer, vinyltoluene-t-butylstyrene copolymer, polymethacrylate and polyacrylate. More preferred are those made of polystyrene, styrene-butadiene copolymer, or styrene-divinylbenzene copolymer.

  The average particle diameter of the organic fine particles is 30 to 3000 nm. The average particle diameter of the organic fine particles is preferably 40 to 1700 nm, and more preferably 100 to 1000 nm. When the average particle size is less than 30 nm, it is difficult to produce particles having a uniform particle size, and thus it is difficult to produce an inorganic porous thin film. On the other hand, when the thickness exceeds 3000 nm, it is difficult to produce particles having a uniform particle diameter, and thus it is difficult to produce an inorganic porous thin film. The average particle diameter of the organic fine particles can be determined by a transmission electron microscope (TEM) method.

  The said coating liquid contains 20-1000 mass parts of said organic fine particles with respect to 100 mass parts of inorganic ultrafine particles. The content of the organic fine particles with respect to 100 parts by mass of the inorganic ultrafine particles is preferably 25 to 600 parts by mass, and more preferably 25 to 400 parts by mass. When the content of the organic fine particles with respect to 100 parts by mass of the inorganic ultrafine particles is less than 20 parts by mass, the organic fine particles are not arranged in a predetermined pattern, making it difficult to produce the inorganic porous thin film of the present invention. Since a sufficient amount of inorganic ultrafine particles do not exist between the organic fine particles, the inorganic porous thin film of the present invention becomes difficult.

  Examples of the dispersion medium used in the coating liquid include alcohols such as methanol, ethanol, 1-propanol, 2-propanol and butanol; ethylene glycols such as ethylene glycol, diethylene glycol and ethylene glycol monoethyl ether; acetone and Examples include ketones such as methyl ethyl ketone; amides such as dimethylformamide or an aqueous solution in which at least one of them is mixed, and water. Among these, water is preferable, and purified water is most preferable.

  Furthermore, in addition to the above components, the coating solution may contain a solution stabilizer such as a surfactant, and alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane. Good.

  Next, each process of the manufacturing method of an inorganic porous thin film is demonstrated, referring drawings. 5A to 5C are process diagrams of the method for manufacturing an inorganic porous thin film according to the embodiment. FIG. 5A is a cross-sectional view showing a state where a sol-like coating liquid 28 in which organic fine particles 22 and inorganic ultrafine particles 24 are dispersed in a dispersion medium 26 is supplied onto the substrate 20. In FIG. 5A, the organic fine particles 22 present in the dispersion medium 26 are arranged on a single layer on the substrate 20, and a plurality of inorganic ultrafine particles 24 are present between the organic fine particles 22.

  Examples of the supply means (coating means) for supplying the coating liquid 28 onto the substrate 20 so as to be in such a state include a spin coater, a gravure coater, and a die coater. When the supply means is a spin coater, the maximum rotational speed at the time of supply (coating) is preferably 1000 to 8000 rpm, more preferably 1500 to 8000 rpm, and further preferably 2000 to 8000 rpm. . If the maximum rotational speed is less than the above lower limit value, spreading of the coating liquid 28 on the substrate 20 tends to be insufficient, and if it exceeds the upper limit value, it becomes difficult to arrange the organic fine particles 22 in a predetermined pattern. .

  Moreover, when a supply means is a gravure coater or a die coater, it is preferable that the film formation rate at the time of supply (at the time of coating) is 1-1000 mm / s, and it is more preferable that it is 5-100 mm / s. When such a film formation rate is less than the lower limit value, the spreading of the coating liquid tends to be insufficient. On the other hand, when the upper limit value is exceeded, it is difficult to arrange organic fine particles in a predetermined pattern. Become.

  As the substrate, a substrate described in the description of the stacked body, that is, a flat substrate made of glass, quartz, silicon, aluminum, or the like can be used.

  FIG. 5B is a cross-sectional view showing a state where the dispersion medium 26 is removed from the coating liquid 28 supplied onto the substrate 20. Removal of the dispersion medium 26 from the coating liquid 28 can be carried out by a known drying method. When a spin coater is used as the supply means, the coating liquid is continuously rotated for a while after coating, The dispersion medium 26 can be removed. Here, at least a part of the dispersion medium 26 may be removed, but it is preferable to remove all of the dispersion medium 26 from the viewpoint of obtaining a more uniform inorganic porous thin film.

  As a result of the removal of the dispersion medium 26, a gel-like thin film 30 in which the organic fine particles 22 are arranged in one layer and the inorganic ultrafine particles 24 are arranged between the organic fine particles 22 is formed on the substrate 20 as shown in FIG. Is done.

  By firing the gel-like thin film 30 thus formed, the organic fine particles 22 can be removed to obtain an inorganic porous thin film. FIG. 5C is a cross-sectional view showing a laminate 100 provided with the inorganic porous thin film 10 obtained by firing the gel thin film 30 on the substrate 20. A laminate 100 shown in FIG. 5 (c) includes an inorganic porous thin film 10 having a large number of holes 5 on a substrate 20, the opening 1 having a substantially circular shape and the inner peripheral surface 3 having a substantially spherical shape. is there.

  In the firing step, the organic fine particles 22 are thermally decomposed and removed by heating, and a plurality of inorganic fine particles 24 existing between the organic fine particles 22 are integrated by sintering or the like to form the inorganic porous thin film 10. Conceivable. In this case, it is presumed that the organic fine particles 22 function as a template for forming holes, and holes are formed corresponding to the arrangement state and particle size of the organic fine particles 22 in the gel thin film 30.

  The firing temperature (heating temperature) in the firing step may be appropriately determined based on the heat-resistant temperature of the substrate to be used, the thermal decomposition (oxidation thermal decomposition, etc.) temperature of the organic fine particles to be used, the temperature at which the inorganic ultra fine particles to be used can be sintered, it can. First, since it is necessary to sinter the gel-like thin film to remove the organic fine particles, the lower limit of the calcination temperature is preferably equal to or higher than the thermal decomposition (oxidative thermal decomposition) temperature of the organic fine particles. Considering the above-mentioned components of suitable organic fine particles, the lower limit of the firing temperature is preferably 350 ° C., more preferably 400 ° C. In addition, since the removal of the organic fine particles is performed by heating the gel-like thin film formed on the substrate, a substrate having heat resistance equal to or higher than the lower limit of the firing temperature may be employed. Also from this point, it is preferable to use the above-described preferred examples as the organic fine particles and use the above-described exemplary materials (glass, quartz, silicon, aluminum, etc.) as the substrate.

  On the other hand, the upper limit of the firing temperature is preferably equal to or lower than the heat resistant temperature of the substrate because the organic fine particles are thermally decomposed on the substrate. From such a viewpoint, the upper limit of the firing temperature is, for example, 1500 ° C. when quartz is used as the substrate, 500 ° C. when glass is used, and 700 ° C. when silicon is used. However, in consideration of obtaining an inorganic porous thin film by removing the organic fine particles and integrating the inorganic ultra fine particles by sintering or the like for the gel thin film in which the inorganic fine particles are arranged between the organic fine particles arranged in one layer. The upper limit of the firing temperature is preferably equal to or lower than the melting point or glass transition temperature of the inorganic ultrafine particles (the lower temperature when the inorganic ultrafine particles exhibit the melting point and the glass transition temperature). It is better to decide in consideration of the circumstances.

  Therefore, the temperature range for firing in the firing step is preferably 350 to 1500 ° C, and more preferably 400 to 500 ° C. If a suitable example is shown for every board | substrate to be used, when using quartz as a board | substrate, 350-1500 degreeC (preferably 350-1000 degreeC, Furthermore, 400-700 degreeC), When using glass as a board | substrate, 350- The temperature is 500 ° C. (preferably 350 to 480 ° C., more preferably 400 to 450 ° C.), and 350 to 700 ° C. (preferably 350 to 500 ° C., more preferably 400 to 500 ° C.) when silicon is used as the substrate. If the firing temperature is less than the lower limit, thermal decomposition (oxidative decomposition, etc.) of the organic fine particles tends to be insufficient and pore formation tends to be difficult. On the other hand, if the upper limit is exceeded, the substrate softens. There exists a tendency for formation of an inorganic porous thin film to become difficult.

  The inorganic porous thin film manufacturing method can improve the lack of practicality of the conventional vertical deposition method (coating speed, productivity, etc.), which has a low coating speed, and can provide a large area in a large amount in a short time. It makes it possible to produce an inorganic porous thin film.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited at all by the following examples.

(Example 1)
First, a soda-lime glass substrate having a diameter of 15 mmΦ and a thickness of 0.27 mm (manufactured by MATUNAMI GLASS, model number: MATUNAMI MICRO COVER GLASS) was immersed in a chrome mixed acid solution to remove stains on the substrate surface. The substrate was washed with distilled water until the chromium mixed acid solution was completely removed and dried at room temperature.

  Next, a sample of a coating liquid containing 0.125 wt% of inorganic ultrafine particles having a particle diameter of 5 nm and 0.5 wt% of organic fine particles having a particle diameter of 136 nm as a solid content and having a total solid content concentration of 0.625 wt% It was prepared using a prepared polycontainer (model number: Newdis Cup (PP, 20 mL)). Silica particles (manufactured by Catalyst Kasei Co., Ltd., model number: SI-550) were used as the inorganic ultrafine particles, and polystyrene latex particles were used as the organic fine particles. Moreover, this coating liquid contained 400 mass parts of organic fine particles with respect to 100 mass parts of inorganic ultrafine particles.

  A glass substrate that has been cleaned and dried is mounted on a spin coater (manufactured by Active, model number: ACT-300D), and an autopipette (manufactured by Eppendorf, model number: Eppendorf reference 4910, 10 to 100 μL) is placed on the glass substrate. The coating solution was put on 100 μL of the coating solution, and then rotated at 2000 rpm for 5 minutes. As a result, the coating liquid could be uniformly applied on a glass substrate and dried, and a substrate on which a gel-like thin film was formed was obtained.

  Thereafter, the substrate was placed in a muffle furnace and baked at 400 ° C. for 5 minutes to produce an inorganic porous thin film. On the surface of the thin film after firing, no significant difference was observed visually compared with that before firing.

  In order to investigate the structure of this inorganic porous thin film, a high-resolution scanning electron microscope (manufactured by JEOL Ltd., model number: JSM-6340F) was observed, and a scanning electron microscope (SEM) photograph was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate.

Moreover, the arrangement | sequence of the hole of the obtained inorganic porous thin film is based on the following criteria:
◎ Well arranged ○ Partially arranged × Evaluated by hardly arranging, and shown in Table 1 (hereinafter, evaluated based on the same criteria). Furthermore, Table 2 shows the average diameter (nm) of the openings of the obtained inorganic porous thin film, the average distance (nm) between the centers of the openings, and the film thickness (nm).

(Example 2)
First, the silica particle (hereinafter abbreviated as “silica”) concentration, polystyrene latex (hereinafter abbreviated as “PSL”) concentration, total solid content, PSL content and PSL particle diameter with respect to 100 parts by mass of silica are shown in Table 1. A coating solution was prepared in the same manner as in Example 1 except that the conditions were satisfied.

  Next, in the same manner as in Example 1, a glass substrate was mounted on a spin coater, and 100 μL of the coating solution was placed on the glass substrate using an autopipette, and the rotation speed was 1000 rpm in 20 seconds. Then, the rotation speed was set to 2000 rpm for 20 seconds, and the rotation was continued for 30 seconds in that state, and the rotation speed was further 3000 rpm for 20 seconds, and the rotation was continued for 300 seconds in that state. As a result, the coating liquid could be uniformly applied on a glass substrate and dried, and a substrate on which a gel-like thin film was formed was obtained. Thereafter, the substrate was placed in a muffle furnace and baked at 400 ° C. for 5 minutes to produce an inorganic porous thin film. On the surface of the thin film after firing, a play-color phenomenon was observed, which was observed when openings having a diameter comparable to the wavelength of visible light were regularly arranged.

  The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and an SEM photograph was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate. In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. In addition, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Example 3)
First, a coating solution was prepared in the same manner as in Example 1, except that the silica concentration, PSL concentration, total solid content concentration, PSL content with respect to 100 parts by mass of silica, and PSL particle diameter were set as shown in Table 1. .

  Next, an inorganic porous thin film was produced in the same manner as in Example 2. In Example 3, a play-color phenomenon was observed on the surface of the fired thin film. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and an SEM photograph was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Example 4)
First, a coating solution was prepared in the same manner as in Example 1, except that the silica concentration, PSL concentration, total solid content concentration, PSL content with respect to 100 parts by mass of silica, and PSL particle diameter were set as shown in Table 1. .

  Next, an inorganic porous thin film was produced in the same manner as in Example 2. Also in Example 4, a play-color phenomenon was observed on the surface of the thin film after firing. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and the SEM photograph shown in FIG. 6 was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate. FIG. 6 is a SEM photograph (5000 times magnification) showing a part of the inorganic porous thin film of Example 4.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Example 5)
First, a coating solution was prepared in the same manner as in Example 1, except that the silica concentration, PSL concentration, total solid content concentration, PSL content with respect to 100 parts by mass of silica, and PSL particle diameter were set as shown in Table 1. .

  Next, an inorganic porous thin film was produced in the same manner as in Example 1. The obtained inorganic porous thin film was observed with a high-resolution scanning electron microscope (the same as in Example 1), and the SEM photograph shown in FIG. 7 was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate. FIG. 7 is an SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Example 5.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Example 6)
First, a coating solution was prepared in the same manner as in Example 1 except that the silica concentration, the PSL concentration, the total solid content concentration, the PSL content with respect to 100 parts by mass of silica, and the PSL particle diameter were the conditions shown in Table 1.

  Next, an inorganic porous thin film was produced in the same manner as in Example 1 except that the number of revolutions during coating was 8000 rpm. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and an SEM photograph was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Example 7)
First, the silica concentration, the PSL concentration, the total solid content concentration, the PSL content with respect to 100 parts by mass of silica and the PSL particle diameter are the conditions shown in Table 1, and as inorganic ultrafine particles, silica particles having a particle diameter of 27 nm (manufactured by Catalyst Kasei Co., Ltd., A coating solution was prepared in the same manner as in Example 1 except that model number: LNA-2000) was used.

  Next, an inorganic porous thin film was produced in the same manner as in Example 1. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and the SEM photograph shown in FIG. 8 was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate. FIG. 8 is an SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Example 7.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Example 8)
First, the silica concentration, the PSL concentration, the total solid content concentration, the PSL content with respect to 100 parts by mass of silica and the PSL particle diameter are the conditions shown in Table 1, and silica particles having a particle diameter of 45 nm (manufactured by Catalyst Kasei Co., Ltd. A coating solution was prepared in the same manner as in Example 1 except that Model No. SI-45P) was used.

  Next, an inorganic porous thin film was produced in the same manner as in Example 1. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and the SEM photograph shown in FIG. 9 was obtained. As a result, it was confirmed that an inorganic porous thin film in which a large number of holes having a predetermined shape were arranged in one layer in a predetermined pattern was formed on the substrate. FIG. 9 is an SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Example 8.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Comparative Example 1)
First, a coating solution was prepared in the same manner as in Example 1, except that the silica concentration, PSL concentration, total solid content concentration, PSL content with respect to 100 parts by mass of silica, and PSL particle diameter were set as shown in Table 1. .

  Next, an inorganic porous thin film was produced in the same manner as in Example 1 except that the number of rotations during coating was 3000 rpm. The obtained inorganic porous thin film was observed with a high-resolution scanning electron microscope (the same as in Example 1), and an SEM photograph shown in FIG. 10 was obtained. As a result, it was confirmed that an inorganic porous thin film having pores scattered irregularly on the substrate was formed. FIG. 10 is an SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Comparative Example 1.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Comparative Example 2)
First, a coating solution was prepared in the same manner as in Example 1, except that the silica concentration, PSL concentration, total solid content concentration, PSL content with respect to 100 parts by mass of silica, and PSL particle diameter were set as shown in Table 1. .

  Next, an inorganic porous thin film was produced in the same manner as in Example 1. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and an SEM photograph was obtained. As a result, it was confirmed that an inorganic porous thin film in which pores exist irregularly on the substrate and the film was locally broken was formed.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. Furthermore, Table 2 shows the average diameter of the openings of the obtained inorganic porous thin film, the average distance between the centers of the openings, and the film thickness.

(Comparative Example 3)
First, the silica concentration, PSL concentration, total solid concentration, PSL content with respect to 100 parts by mass of silica and the PSL particle diameter are the conditions shown in Table 1, and silica particles having a particle diameter of 74 nm (manufactured by Catalyst Kasei Co., Ltd. A coating solution was prepared in the same manner as in Example 1 except that Model No. SI-80P) was used.

  Next, an inorganic porous thin film was produced in the same manner as in Example 1. The obtained inorganic porous thin film was observed with a high resolution scanning electron microscope (the same as in Example 1), and the SEM photograph shown in FIG. 11 was obtained. As a result, it was confirmed that the inorganic porous thin film does not have many holes where the “opening has a substantially circular shape and the inner peripheral surface has a substantially spherical shape”, and the uniformity of the hole arrangement is poor. It was done. FIG. 11 is an SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Comparative Example 3.

  In addition, the pore arrangement of the obtained inorganic porous thin film was evaluated and shown in Table 1. In addition, in the inorganic porous thin film, there are many places where the “opening has a substantially circular shape and the inner peripheral surface has a substantially spherical shape”, and the uniformity of the hole arrangement is inferior. The average diameter of the part, the average distance between the centers of the openings, and the film thickness were not measured.

1: JSR, model number: STADEX SC-014-S
2: Made by JSR, model number: STADEX SC-046-S
3: Made by JSR, model number: STADEX SC-051-S
4: Made by JSR, model number: STADEX SC-061-S
5: manufactured by JSR, model number: IMMUTEX G2110

  As can be seen from the results shown in Tables 1 and 2, the inorganic porous thin films of Examples 1 to 8 produced using the coating liquid that satisfies the conditions of the method for producing the inorganic porous thin film of the present invention are the substrates. It was confirmed that an inorganic porous thin film of the present invention was obtained by forming a thin film having a large area and a large number of holes having a predetermined shape arranged in a single layer in a predetermined pattern. On the other hand, the inorganic porous thin films of Comparative Examples 1 and 2 produced using a coating solution that does not satisfy the conditions in the method for producing an inorganic porous thin film of the present invention were irregularly interspersed with pores. . Moreover, since the particle diameter of the inorganic ultrafine particles exceeds 50 nm, a uniform inorganic porous thin film is not formed in Comparative Example 3 using the coating liquid that does not satisfy the conditions in the method for producing the inorganic porous thin film of the present invention. It was.

It is a perspective view of the layered product concerning an embodiment. It is sectional drawing along the II-II line of the laminated body of FIG. It is a schematic diagram of an inorganic porous thin film in which openings are arranged in hexagonal symmetry. It is sectional drawing of the laminated body which concerns on other embodiment. It is process drawing of the manufacturing method of the inorganic porous thin film which concerns on embodiment, (a) is sectional drawing which shows the state with which the coating liquid was supplied on the board | substrate, (b) is the coating liquid supplied on the board | substrate. Sectional drawing which shows the state from which the dispersion medium was removed from, (c) is sectional drawing which shows the laminated body obtained by baking. 4 is a SEM photograph (a magnification of 5000 times) showing a part of the inorganic porous thin film of Example 4. 6 is a SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Example 5. 4 is a SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Example 7. 10 is a SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Example 8. 3 is a SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Comparative Example 1. 4 is a SEM photograph (magnification 20000 times) showing a part of the inorganic porous thin film of Comparative Example 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Opening part, 3 ... Inner peripheral surface, 5 ... Hole, 10 ... Inorganic porous thin film, 20 ... Substrate, 22 ... Organic fine particle, 24 ... Inorganic ultrafine particle , 26 ... dispersion medium, 28 ... coating solution, 30 ... gel-like thin film, 100 ... laminate, d1 ... average diameter of openings, d2 ... between the centers of openings Mean distance, d3... Film thickness, d4... Mean depth of holes.

Claims (11)

An inorganic porous thin film having a large number of pores having a substantially circular opening and a substantially spherical inner peripheral surface,
The holes are arranged in one layer in the plane direction of the thin film, the average diameter of the openings is 30 to 3000 nm, and the average distance between the centers of the adjacent openings is 100 to 230 of the average diameter of the openings. %, And the film thickness is 30 to 100% of the average diameter of the openings.   2. The inorganic porous thin film according to claim 1, wherein the openings are arranged in a hexagonal symmetry.   The inorganic porous thin film according to claim 1 or 2, wherein the average depth of the holes is 50 to 100% of the film thickness.   A laminate comprising: a substrate; and the inorganic porous thin film according to any one of claims 1 to 3 formed on at least one surface of the substrate. A sol-like coating liquid in which inorganic ultrafine particles having an average particle diameter of 3 to 50 nm and organic fine particles having an average particle diameter of 30 to 3000 nm are dispersed in a dispersion medium (provided that organic fine particles have a larger average than inorganic ultrafine particles) And a coating liquid having a total solid content concentration of 0.1 to 20% by mass and a content of the organic fine particles of 20 to 1000 parts by mass with respect to 100 parts by mass of the inorganic ultrafine particles. By removing at least a part of the dispersion medium from the supplied coating liquid, the organic fine particles are arranged in a single layer on the substrate, and the inorganic ultrafine particles are arranged between the organic fine particles. A coating process for forming a gel-like thin film;
A baking step of removing the organic fine particles by baking the obtained gel-like thin film to obtain an inorganic porous thin film;
The manufacturing method of the inorganic porous thin film characterized by including.   6. The method for producing an inorganic porous thin film according to claim 5, wherein the inorganic ultrafine particles are made of silica.   7. The method for producing an inorganic porous thin film according to claim 5, wherein the organic fine particles are made of a polymer.   The inorganic porous thin film production according to any one of claims 5 to 7, wherein the supply means for supplying the coating liquid in the coating step is a spin coater, a gravure coater or a die coater. Method.   9. The method for producing an inorganic porous thin film according to claim 8, wherein the supply means is a spin coater, and the maximum rotation speed during coating is 1000 to 8000 rpm.   9. The method for producing an inorganic porous thin film according to claim 8, wherein the supplying means is a gravure coater or a die coater, and a film forming speed during coating is 1-1000 mm / s.   In the firing step, the gel-like thin film at a temperature equal to or higher than the thermal decomposition temperature of the organic fine particles and not higher than the melting point or glass transition temperature of the inorganic ultrafine particles (the lower temperature when the inorganic ultrafine particles exhibit the melting point and glass transition temperature). The method for producing an inorganic porous thin film according to claim 5, wherein the inorganic porous thin film is fired.

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