JP3960882B2 - Method for producing titania nanocrystallite dispersed thin film pattern - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of this application is intended to relate to the production how the titania fine crystal dispersion film pattern. More specifically, the invention of this application, titania microcrystal dispersion thin film, an arbitrary site of the substrate, relates to the production how the titania fine crystal dispersion film patterns that are distributed as any pattern of submicron order It is.
[0002]
[Prior art and its problems]
Conventionally, titania's characteristics such as photocatalytic activity and super hydrophilicity have attracted attention, including titania thin films, titania-dispersed thin films (SiO ₂ —TiO ₂ based thin films) mainly composed of silica and titania, etc. Development of products having a wide range of functions such as purification, antibacterial, and antifouling using a thin film containing titania has been promoted and put into practical use.
[0003]
The mild this titania dispersion film (SiO ₂ -TiO ₂ based thin film) is the inventors of this application, the gel film was prepared by coating a sol consisting of a titanium alkoxide and silicon alkoxide, that warm water it By processing under various conditions, a method for producing a titania microcrystal-dispersed thin film in which anatase-type titania microcrystals are deposited (PCT / JP99 / 00477) and hot water with strictly controlled composition of SiO ₂ —TiO ₂ gel A method of producing a titania microcrystal-dispersed transparent thin film on which surface titania microcrystals having an interlayer distance of about 0.7 nm and exhibiting superhydrophilicity and excellent photocatalytic activity are treated (Japanese Patent Application No. 2000-289528) ) Furthermore, by applying warm water treatment with vibration, it exhibits high photocatalytic activity and excellent superhydrophilic properties. In addition, a novel method for producing a titania nanosheet oriented thin film in which titania nanosheets are oriented and deposited that can maintain antifogging properties for a long time (Japanese Patent Application No. 2002-053480) has been proposed.
[0004]
However, although the titania-dispersed thin film obtained by these methods exhibits high photocatalytic activity, there is a drawback in that there is no reaction selectivity of the photocatalytic reaction and almost all organic substances in contact are decomposed. That is, for example, in this titania-dispersed thin film, an arbitrary superhydrophilic-superhydrophobic pattern can be formed by applying a fluoroalkylsilane exhibiting superwater repellency and irradiating with ultraviolet rays through a photomask. However, the superhydrophobic portion of the superhydrophilic-superhydrophobic pattern is decomposed by irradiation with ultraviolet rays during long-term use. Thus, the conventional titania-dispersed thin film has also decomposed organic substances and the like disposed on the substrate for the purpose of imparting design and other functionality.
[0005]
Accordingly, the invention of this application has been made in view of the circumstances as described above, and titania nano fine particles in which a titania nano fine crystal-dispersed thin film is dispersed in an arbitrary pattern of a submicron order at an arbitrary portion of a substrate. It has an object to provide a manufacturing how the crystal dispersion film pattern.
[0006]
[Means for Solving the Problems]
Therefore, the invention of this application provides the following invention as a solution to the above-mentioned problems.
[0007]
That is, firstly, the invention of this application relates to a composite metal oxide of silicon alkoxide and titanium compound modified with β-diketone from a solution containing silicon alkoxide, hydrolyzable titanium compound and β-diketone. Alternatively, a film containing hydroxide is formed, and this film is masked with a desired pattern and irradiated with ultraviolet rays. After curing the ultraviolet irradiation portion, the non-irradiation portion is etched, and then contacted with water or hot water. And providing a method for producing a titania nanocrystallite-dispersed thin film pattern, characterized in that titania microcrystals are deposited on the surface of an ultraviolet irradiation portion.
[0008]
According to the invention of this application, in the above invention, secondly, the titania nano fine particles characterized in that the β-diketone is one or a mixture of two or more of acetylacetone, ethylacetoacetate, and benzoylacetone. Thirdly, the method for producing a crystal-dispersed thin film pattern is characterized in that the silicon alkoxide and the titanium compound are mixed in a molar ratio of SiO ₂ : TiO ₂ = 5: 1 to 1: 3. A method for producing a titania nano fine crystal dispersed thin film pattern. Fourth, the titania nano fine crystal dispersion is characterized in that the silicon alkoxide and the titanium compound are mixed in a molar ratio of SiO ₂ : TiO ₂ = 3: 1. A method for producing a thin film pattern, fifthly, β-diketone is a molar ratio of 1: 0.5 to 10 with respect to the titanium compound. A sixth method for producing a titania nanocrystallite-dispersed thin film pattern, characterized in that the β-diketone is added at a molar ratio of 1: 2 with respect to the titanium compound. A method for producing a titania nano fine crystal dispersed thin film pattern characterized by the following: seventh, a method for producing a titania nano fine crystal dispersed thin film pattern characterized by etching using an acid, alkali, acidic salt or alkaline salt solution as an etching solution Eighth, the present invention provides a method for producing a titania nanocrystallite dispersed thin film pattern, wherein the etching solution is any one of NaOH solution, KOH solution, and NH ₃ solution.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The invention of this application has the features as described above, and an embodiment thereof will be described below.
[0011]
In the manufacture of titania nanocrystallite-dispersed thin films, the inventors of this application have (1) silicon alkoxide and a hydrolyzable titanium compound to form a chelate compound with β-diketone, and (2) the chelated silicon alkoxide and Titanium compounds are difficult to hydrolyze because they are difficult to hydrolyze, and (3) a thin film on which titania nanocrystallites are deposited is exploited by utilizing the characteristic that the chelate bond in this chelate compound is cleaved by ultraviolet irradiation. It succeeded in forming in an arbitrary pattern at a desired position of the substrate, leading to the invention of this application.
[0012]
That is, the method for producing a titania nano-crystal-dispersed thin film provided by the invention of this application includes a silicon alkoxide, a hydrolysable titanium compound, and a solution containing β-diketone, a silicon alkoxide modified with β-diketone and a titanium compound. A film containing a composite metal oxide or hydroxide of the above is formed, this film is masked with a desired pattern and irradiated with ultraviolet rays, the ultraviolet irradiation portion is cured, the non-irradiation portion is etched, and then water is added. Alternatively, it is characterized in that titania microcrystals are deposited on the surface of the ultraviolet irradiation part by contacting with warm water.
[0013]
In the invention of this application, as the silicon alkoxide, for example, various types represented by the general formula Si (OR) ₄ can be used. Here, as the organic group R constituting the alkoxyl group OR, for example, the same or different lower alkyl having 1 to 6 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, etc. The group can be mentioned. More specifically, for example, the use of silicon tetraethoxide is shown as a preferred example.
[0014]
In addition, as the titanium compound having hydrolyzability, for example, titanium alkoxide, titanium oxalate, which is a metal organic compound, titanium nitrate, titanium tetrachloride, etc. can be used as the metal inorganic compound, and more preferably, titanium alkoxide. Is exemplified. Specific examples of the titanium alkoxide include tetramethoxy titanium, tetraethoxy titanium, tetra n-propoxy titanium, tetraisopropoxy titanium, tetra n-butoxy titanium, and tetraisobutoxy titanium.
[0015]
As the β-diketone, various compounds represented by the general formula R ₁ COCH ₂ COR ₂ can be used. Here, R ₁ and R ₂ in the formula represent an organic group such as an aliphatic hydrocarbon group such as a methyl group or an ethyl group, an aromatic hydrocarbon group such as a phenyl group or a benzyl group, a methoxy group or an ethoxy group. The same or different ones can be selected from such ether groups. In the invention of this application, it is shown as a preferred example that one or a mixture of two or more of acetylacetone, ethylacetoacetate or benzoylacetone is used as the β-diketone.
[0016]
These starting materials are dissolved in an organic solvent to prepare a solution. In preparing the solution, for example, it is convenient to mix a silicon alkoxide solution in which silicon alkoxide is dissolved in an organic solvent and a titanium solution in which a titanium compound and a β-diketone are dissolved in an organic solvent. Of course, without being limited thereto, β-diketone may be added to the silicon alkoxide solution, or all may be mixed in the same manner.
[0017]
Here, examples of the organic solvent include methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, ter-butyl alcohol, 1-pentanol, 2-pentanol, and 3-pen. Tanol or the like can be used. Moreover, you may add the catalyst and water for accelerating the hydrolysis of an alkoxyl group or accelerating dehydration condensation reaction to these solutions as needed. Examples of the catalyst include use of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, ammonia and the like.
[0018]
The formulation of these solutions should be about 1 to 8, 1 to 6 for the organic solvent and water added to the silicon alkoxide, and about 20 for the organic solvent added to the titanium compound. Is appropriate. In addition, for example, β-diketone is added so that the molar ratio is about 0.5 to 10 and more preferably about 2 with respect to the titanium compound.
[0019]
Further, the silicon alkoxide solution and the titanium solution are adjusted so that the silicon alkoxide and the titanium compound have a molar ratio of SiO ₂ : TiO ₂ = 5: 1 to 1: 3, more preferably around 3: 1. can do. By setting the molar ratio of the titanium compound and silicon alkoxide to around 3: 1, the photocatalytic activity of the obtained titania microcrystal dispersed thin film portion can be further increased.
[0020]
A solution containing silicon alkoxide, titanium compound and β-diketone prepared in this manner is applied onto a substrate, for example, a composite metal oxide or hydroxide of silicon alkoxide and titanium compound modified with β-diketone. A film containing an object is formed.
[0021]
This film formation can be performed on an arbitrary substrate using various methods such as a dip coating method, a spray method, and a spin coating method. The substrate is not particularly limited in its material and shape, and can be various materials such as glass materials, metal materials, inorganic materials, plastic materials, paper, and wood materials. Since the invention of this application produces a titania microcrystal-dispersed thin film pattern under mild conditions of 100 ° C. or less, it is possible to use, for example, an organic polymer or a living tissue as a base material.
[0022]
As described above, the silicon alkoxide and the titanium compound react with the β-diketone to form a chelate compound. The chelated silicon alkoxide and titanium compound are in a state in which they are hardly hydrolyzed and gelled. Furthermore, the chelate bond in this chelate compound has the property of being cleaved by ultraviolet irradiation.
[0023]
Therefore, the chelated film is irradiated with ultraviolet rays through a mask having a desired pattern. As a result, the chelate bond is opened only in the portion of the film irradiated with ultraviolet rays, and gelation proceeds. On the other hand, since the gelation of the film has not progressed in the part not irradiated with ultraviolet rays, for example, various acid solutions, alkaline solutions, acidic salt solutions or alkaline salt solutions can be used as etching solutions for easy etching. can do. This etching solution is more preferably an alkaline solution, and it is preferable to use any one of a NaOH solution, a KOH solution, and a NH ₃ solution because it is simple. In the ultraviolet irradiation part, the film is gelled and densified, and is not attacked by the etching solution. Thereby, the film | membrane provided with the desired pattern can be obtained.
[0024]
The patterned membrane is then contacted with water or warm water. In this case, the temperature of the hot water can be set to 100 ° C. or lower, more preferably from about room temperature to 100 ° C., more preferably in the range of about 50 to 100 ° C. More efficiently, the hot water can be about 90 ° C. The treatment time varies depending on the composition of the gel film, the temperature of the hot water to be used, and the like, but it cannot be said unconditionally, but can be arbitrarily determined so that the precipitation state of titania microcrystals becomes a desired one. In general, about several tens of minutes to several hours can be used as a guide. In addition, it can also consider adding a vibration simultaneously with the process by this warm water.
[0025]
Thereby, a film in which titania microcrystals are selectively dispersed according to the ultraviolet irradiation pattern can be formed on the substrate, and a desired titania nanocrystallite dispersed thin film pattern can be obtained.
[0026]
The titania microcrystal dispersed thin film pattern of the invention of the present application obtained in this way has a titania microcrystal dispersed thin film formed in an arbitrary arrangement on the substrate, and the portion where the titania microcrystal is deposited has high photocatalytic activity. It has functions such as super hydrophilicity and antifogging properties. Further, the titania microcrystal precipitation pattern can be controlled in an arbitrary shape on the order of submicrons by an ultraviolet irradiation technique.
[0027]
Furthermore, in the titania microcrystal-dispersed thin film pattern of the invention of this application, at least one organic functional film can be formed in addition to the titania microcrystal precipitates. Since this organic functional film does not come into contact with titania, it does not decompose even when used for a long period of time, and can maintain its function. As such a functional film, a coating film for design, a super water-repellent film, a conductive film, and other films having various functions can be considered. These organic functional films are formed, for example, on the surface of a titania microcrystal-dispersed thin film pattern in which titania microcrystals are deposited in the above-described pattern, and then irradiated with ultraviolet rays, thereby being present on the titania precipitate portion. It can be produced by decomposing a functional membrane.
[0028]
In addition, an article provided by the invention of this application is characterized by including any one of the above-mentioned titania nanocrystallite-dispersed thin film patterns. This titania nanocrystallite-dispersed thin film pattern can be manufactured in any pattern on the order of submicrons without being limited to the material of the substrate, its part, etc., and in combination with other various functional films, Articles having various functions can be realized.
[0029]
Examples will be shown below, and the embodiments of the present invention will be described in more detail.
[0030]
【Example】
A titania nanocrystallite-dispersed thin film pattern of the invention of this application was manufactured along the process diagram shown in FIG.
[0031]
The starting materials include tetraethoxysilane (Si (OEt) ₄ : manufactured by Wako Pure Chemical Industries, Ltd., reagent grade, hereinafter referred to as TEOS) as a silicon alkoxide, and titanium tetranormal butoxide as a hydrolyzable titanium compound. (Ti (On-Bu) ₄ : manufactured by Wako Pure Chemical Industries, Ltd., reagent grade 1, hereinafter referred to as TBOT), acetylacetone (hereinafter referred to as AcAc) as β-diketone, ethanol (hereinafter referred to as “AcAc”) A sol solution was prepared using TtOH as a solvent. Moreover, what diluted 36 wt% hydrochloric acid (the Wako Pure Chemical Industries Ltd. make, reagent special grade) 10 times as a hydrolysis catalyst was used.
[0032]
To prepare the sol solution, first, 3.6 wt% hydrochloric acid is added to a solution in which TEOS, water, and EtOH are mixed, and the mixture is stirred for 30 minutes. Then, an EtOH solution of TBOT chemically modified with AcAc is added dropwise to promote hydrolysis. Therefore, it was stirred for 30 minutes to obtain a sol solution. The respective formulations were in the order of molar ratios, TEOS: water: EtOH: TBOT: EtOH = 83.5: 16.5: 334.0: 417.5: 330, TBOT: AcAc = 1: 2.
[0033]
This sol solution was applied to a non-alkali glass substrate with one side covered with a mending tape by a dip coating method with a pulling rate of 1.11 mm / sec. After the substrate tape was peeled off, it was dried at 90 ° C. for 1 hour. To obtain a membrane (a). The film (a) had a thickness of 210 nm.
[0034]
As shown in FIG. 1 (1), the film (a) is irradiated with ultraviolet rays through a photomask for 1 hour, and then immersed in 0.1M NaOHaq as shown in FIG. 1 (3). And etched to obtain a film (b). Further, this film (b) was immersed in boiling water for 1 hour together with the substrate to obtain a film (c) as shown in FIG. 1 (4). Note that a photomask having square openings with sides of 40 μm provided at intervals of 100 μm was used.
[0035]
The pattern shapes of the above films (a) to (c) were observed with an optical microscope (manufactured by Olympus Optical Co., Ltd., BX50), and the surface shape was measured with a surface roughness measuring instrument (manufactured by Kosaka Laboratory, Surfcorder SE- 30C) and measured using 3D surface roughness shape analysis software (TDA-22). The measurement conditions of the surface shape were a stylus feed speed of 0.5 mm / s, a feed pitch of 10 μm, a number of lines of 101, and a Z magnification of 50000 times.
[0036]
The results of the optical microscope observation of the films (a) to (c) are shown in FIG. 2, and the results of the three-dimensional surface roughness shape analysis are shown in FIG. Nine square portions in the figure are ultraviolet irradiation portions. In (a), it was found that the thickness was about 10 nm in the ultraviolet irradiation part, and the film was densified by the ultraviolet irradiation. In (b), it was found that the thickness was reduced and the substrate was exposed in the unirradiated part, and the unirradiated part was easily etched, and the solubility in the etching solution was reduced by irradiating with ultraviolet light. In (c), it was confirmed that although the film contracted by about 10 to 20 nm only in the thickness direction, the pattern shape was maintained.
[0037]
Furthermore, about the film | membrane (c), the structure | tissue was observed with the electrolytic emission type | mold scanning microscope (The Hitachi Ltd. make, S4500 type | mold, hereafter shown as FE-SEM). For the sample, the thin film is cut with a diamond glass cutter together with the substrate, fixed to the sample stage with silver paste, vacuum dried for about 30 minutes in a vacuum desiccator, and then used with a quick coater (VPS-020 manufactured by ULVAC, Inc.). And prepared by platinum sputtering. The conditions for FE-SEM observation were an acceleration voltage of 5 to 15 kV and a scanning distance of 5 mm.
[0038]
FIG. 4 shows the result of FE-SEM observation of the ultraviolet ray irradiated part (A) and the ultraviolet ray non-irradiated part (B) of the film (c). (A) Although granular precipitates are observed in the ultraviolet irradiation part, (B) it was not observed in the ultraviolet non-irradiation part. An electron diffraction pattern of the granular precipitate is shown in FIG. This diffraction pattern was confirmed to be in very good agreement with the anatase titania pattern obtained by calculation. From this, it was shown that anatase-type titania is also deposited by warm water treatment on a film modified with β-diketone and patterned by ultraviolet irradiation and etching.
[0039]
Of course, the present invention is not limited to the above examples, and it goes without saying that various aspects are possible in detail.
[0040]
【The invention's effect】
As described above in detail, the present invention, titania microcrystal dispersion thin film, an arbitrary site of the substrate, titania microcrystal dispersed film pattern manufacturing how that are distributed as any pattern of submicron order is provided The
[Brief description of the drawings]
FIG. 1 is a process diagram illustrating a method for producing a titania nanocrystallite-dispersed thin film according to the invention of this application.
FIG. 2 is a diagram illustrating the results of optical microscope observation of films (a) to (c) obtained in Examples.
FIG. 3 is a diagram exemplifying results of three-dimensional surface roughness shape analysis of films (a) to (c) obtained in Examples.
FIG. 4 is a diagram exemplifying the result of FE-SEM observation of an ultraviolet irradiation part (A) and an ultraviolet non-irradiation part (B) of a film (c) obtained in an example.
FIG. 5 is a diagram exemplifying an electron beam diffraction pattern in an ultraviolet irradiation part (A) of a film (c) obtained in an example.

Claims (8)

  A film containing a composite metal oxide or hydroxide of silicon alkoxide modified with β-diketone and a titanium compound is formed from a solution containing silicon alkoxide, a hydrolyzable titanium compound and β-diketone, and this film is formed. Mask with a desired pattern and irradiate with ultraviolet rays to cure the ultraviolet irradiation part, then etch the non-irradiation part, and then contact with water or warm water to deposit titania microcrystals on the surface of the ultraviolet irradiation part A method for producing a titania nanocrystallite-dispersed thin film pattern.   2. The method for producing a titania nanocrystallite dispersed thin film pattern according to claim 1, wherein the β-diketone is one or a mixture of two or more of acetylacetone, ethylacetoacetate, and benzoylacetone. 3. The titania nano-microcrystalline dispersed thin film pattern according to claim 1, wherein the composition of the silicon alkoxide and the titanium compound is in a range of molar ratio of SiO ₂ : TiO ₂ = 5: 1 to 1: 3. Production method. 4. The method for producing a titania nanocrystallite dispersed thin film pattern according to claim 3, wherein the silicon alkoxide and the titanium compound are mixed in a molar ratio of SiO ₂ : TiO ₂ = 3: 1.   The production of a titania nanocrystallite dispersed thin film pattern according to any one of claims 1 to 4, wherein β-diketone is added at a molar ratio of 1: 0.5 to 10 with respect to the titanium compound. Method.   6. The method for producing a titania nanocrystallite-dispersed thin film pattern according to claim 5, wherein β-diketone is added at a molar ratio of 1: 2 with respect to the titanium compound.   The method for producing a titania nanocrystallite dispersed thin film pattern according to any one of claims 1 to 6, wherein the etching is performed using an acid, an alkali, an acidic salt, or an alkaline salt solution as an etching solution. 8. The method for producing a titania nanocrystallite dispersed thin film pattern according to claim 7, wherein the etching solution is any one of NaOH solution, KOH solution, and NH ₃ solution.

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