JP2006247915A - Manufacturing method of three-dimensional structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a three-dimensional structure packed with fine particles almost uniform in particle size in the closest packing state. <P>SOLUTION: The three-dimensional structure is manufactured by forming at least two closest packing layers of fine particles using a process for preparing a liquid containing fine particle comprising polystyrene, silica or the like and almost uniform in particle size within a range of 100-2,000 nm, a process for dropping the liquid on a substrate, a process for emitting ultrasonic waves to the substrate and a process for coating the surface of a fine particle layer with a metal oxide thin film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a three-dimensional structure that can be used for an optical material or the like using an optical effect.

  Traditionally, three-dimensional structures have attracted great interest because they can be used as optical filters, optical switches, waveguides, low threshold laser applications, and the like.

Therefore, various techniques for obtaining a three-dimensional structure (fine crystal) have been studied. For example, gravity deposition method (Non-patent document 1), vertical deposition method (Non-patent document 2), improved vertical deposition method (Non-patent document 3), membrane filtration method (Non-patent document 4), under heating Evaporation self-organization (Non-Patent Document 5), crystallization on a fluid substrate (Non-Patent Document 6), and the like are known. However, in the deposition method, the applicable particle diameter is limited (only less than 500 nm or only 500 nm or more), and it is difficult to stack a plurality of layers. In addition, these methods have a problem that expensive equipment is required for deposition, or a long time (about 1 day to several weeks) is required.
Under such circumstances, there is a demand for a method for producing a three-dimensional structure that can be applied to fine particles having a wide range of particle sizes in a short time.

J. Nature 1997, 385, 321-324. J. Nature 2001, 414, 289-293 Langmuir 2004, 20, 1524-1526 Nature 1997, 389, 447-448 J. Am. Chem. Soc. 2003, 125, 15589 Chem. Master. 2002, 14, 4023-4025

  The object of the present invention is to provide a method for producing a three-dimensional structure that can be applied to a wide range of fine particles in a short time.

  As a result of intensive studies by the inventor under the above problems, it has been found that the problems of the present invention can be solved by the following means.

(1) A method for producing a three-dimensional structure including a step of emitting ultrasonic waves to a substrate on which a liquid containing fine particles having a particle diameter of 100 nm to 2000 nm and a substantially uniform particle diameter is placed.
(2) The three-dimensional structure manufacturing method according to (1), wherein the three-dimensional structure is closely packed with fine particles.
(3) The method for producing a three-dimensional structure according to (1) or (2), wherein the three-dimensional structure is a laminate of two or more fine particle layers.
(4) The method for producing a three-dimensional structure according to any one of (1) to (3), wherein the fine particles are polystyrene.
(5) The method for producing a three-dimensional structure according to any one of (1) to (3), wherein the fine particles are silica.
(6) The method for producing a three-dimensional structure according to any one of (1) to (5), wherein the three-dimensional structure is formed by stacking five or more fine particles.
(7) The method for producing a three-dimensional structure according to any one of (1) to (6), wherein the defect ratio is 1% or less.
(8) The method for producing a three-dimensional structure according to any one of (1) to (7), further comprising a step of coating the surface of the laminated fine particle layer with a metal oxide thin film.
(9) A three-dimensional structure including a step of placing a liquid containing fine particles having a particle diameter of 100 to 2000 nm and a substantially uniform particle diameter on only a specific part of the substrate and emitting ultrasonic waves to the substrate Manufacturing method.

By employing the manufacturing method of the present invention, it has become possible to easily manufacture a three-dimensional structure in a shorter time than before. Furthermore, the production method of the present invention has an effect that it can be applied to a wide range of particle sizes.
Further, the production method of the present invention can be applied to various types of fine particles, and the size thereof can be applied in a wide range of 100 nm to 2000 nm. For this reason, industrial use is expected.
Furthermore, in the production method of the present invention, a plurality of layers can be laminated, and the utility value is high from this viewpoint.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

  The three-dimensional structure in the present specification refers to a structure in which at least one fine particle layer is regularly stacked on a substrate. In particular, a laminate of two or more layers is preferable.

In the method for producing a three-dimensional structure according to the present invention, a fine particle having a particle diameter of 100 nm to 2000 nm can be adopted, and preferably 100 nm to 1500 nm. Thus, in the present invention, particles having a particle diameter of 100 nm or more and less than 500 nm or products having a particle diameter of 500 nm or more and 2000 nm or less can be manufactured, and thus there is an advantage that the application range is wide.
Further, in the three-dimensional structure of the present invention, the particle system of the fine particles is substantially uniform. The term “substantially uniform” as used herein may be uniform so that the fine particle layer can be regularly stacked, and does not necessarily require that the particle diameters are completely the same.
The fine particles referred to in the present invention are preferably spherical, but need not be completely spherical, and include those that can be regarded as substantially spherical within the scope of the present invention. The particle diameter in the case of a substantially spherical shape can be the particle diameter having an average particle diameter.

The kind of fine particles is not particularly defined, and fine particles made of various materials (or raw materials) can be used, and examples thereof include inorganic fine particles and organic fine particles.
As inorganic fine particles, periodic table group 1 elements such as lithium, sodium, potassium, rubidium and cesium; periodic table group 2 elements such as magnesium, calcium, strontium and barium; scandium, yttrium and lanthanoid elements (such as lanthanum and cerium), Periodic Table Group 3 elements such as actinoid elements (actinium, etc.); Periodic Table Group 4 elements such as titanium, zirconium, hafnium; Periodic Table Group 5 elements such as vanadium, niobium, tantalum; Periodic Table 6 such as chromium, molybdenum, tungsten, etc. Group elements: Periodic Table 7 elements such as manganese, technetium, rhenium; Periodic Table 8 elements such as iron, ruthenium, osmium; Periodic Table 9 elements such as cobalt, rhodium, iridium; Periods such as nickel, palladium, platinum, etc. Group 10 elements; Group 11 elements of the periodic table such as copper, silver, gold ; Group 12 elements of the periodic table such as zinc, cadmium and mercury; Group 13 elements of the periodic table such as boron, aluminum, gallium, indium and thallium; Group 14 elements of the periodic table such as silicon, germanium, tin and lead; Antimony, bismuth and the like In particular, particulate inorganic compounds containing inorganic atoms (inorganic elements) such as Group 15 elements of the periodic table are included. The inorganic compound may contain one kind or two or more kinds of inorganic atoms. As long as it has the form of fine particles, the inorganic fine particles may be composed of simple inorganic elements, including inorganic element oxides (including complex oxides), hydroxides, halides (chlorides, etc.), Oxo acid salts (nitrate, sulfate, phosphate, carbonate, etc.) may be used. As the inorganic fine particles, fine particles containing a group 14 element of the periodic table are preferable, and silicon fine particles containing a silicon atom are more preferable.

  Examples of organic fine particles include polydienes such as polyisoprene and polybutadiene; polyalkenes such as polyisobutylene; polyacrylates such as polybutyl acrylate and polyethyl acrylate; polyvinyl esters such as polybutoxymethylene; polyurethane Polysiloxanes; polysulfides; polyphosphazenes; polytriazines; polycarboranes; polycarbonate resins (PC); methacrylate resins such as polymethyl methacrylate (PMMA); polyester resins such as polyethylene terephthalate (PET); Polyethersulfone (PES) (polyethersulfone); Polynorbornene; Epoxy resin; Polyaryl; Polyimide; Polyetherimide (PEI); Polyamideimide; Reesterimide; Polyamide; Polystyrene, polystyrene, acrylonitrile-styrene copolymer (AS resin), styrene resin such as acrylonitrile-butadiene-styrene copolymer (ABS resin); polyarylene ether such as polyphenylene ether; polyarylate; polyacetal; Polysulfone (polysulfone); Polyether ketones such as polyether ether ketone and polyether ketone ketone; Polyvinyl alcohol; Polyvinyl pyrrolidone; Fluorine-based resins such as vinylidene fluoride resin, hexafluoropropylene resin, hexafluoroacetone resin Resin etc. are mentioned. As the organic fine particles, fine particles containing a styrene resin are preferable, and fine particles containing polystyrene are more preferable.

  Furthermore, fine particles in which pigments and dyes are applied to the surface of these fine particles, or fine particles whose adhesion is exhibited by heating, light, or the like can be employed.

In the present invention, fine particles are dispersed in a liquid. The liquid used here is not particularly defined, and a wide variety of solvents can be employed. Specifically, water, an organic solvent, etc. are mentioned. The liquid is preferably one in which 30 μl is volatilized (evaporated) at 18 ° C. within 3 hours, more preferably volatilized within 2 hours, and more preferably volatilized within 30 minutes.
The concentration of the fine particles in the liquid can be appropriately determined according to the number of stacked layers and the size of the substrate, and is, for example, 0.1 to 5% by mass.

In the present invention, a liquid containing fine particles is used on a substrate. Here, the method of placing the substrate on the substrate is not particularly defined, but it is preferable to drop the substrate with a dropoid or the like.
Therefore, in the present invention, a three-dimensional structure can be laminated only on a specific part of the substrate by dropping a liquid containing fine particles with a spoid or the like only on a specific part of the substrate. By adopting such means, various three-dimensional structures can be manufactured. For example, a three-dimensional structure made of different fine particles for each region of the substrate can be manufactured.

In the present invention, the fine particles are laminated on the substrate by emitting ultrasonic waves. The ultrasonic conditions are not particularly defined, but the frequency is preferably 10 to 50 kHz, and more preferably 20 to 40 kHz. The time for emitting the ultrasonic wave can be determined in consideration of easiness of volatilization of the liquid to be employed, but for example, for water, it is preferably 10 minutes to 2 hours, and 30 minutes to 1 hour. More preferably.
A method for emitting ultrasonic waves is not particularly defined, but for example, a high-frequency voltage can be applied to a transducer for emission.

The substrate used in the production method of the present invention is not particularly defined, and can be appropriately determined according to the use of the three-dimensional structure. For example, an insulating support, a semiconductor support, a plastic film, a glass plate, a wooden board, cardboard, etc. can be widely used. Furthermore, as the insulator support, silicon oxide, silicon nitride, aluminum oxide, titanium oxide, calcium fluoride, acrylic resin, epoxy resin and other insulating resins, polyimide, Teflon (
Registered trademark), a photo-radical polymer, a novolac resin, and the like. As the semiconductor support, silicon, germanium, gallium arsenide, indium phosphide, silicon carbide, or the like can be used.
The surface of the substrate employed in the present invention is preferably flat. Moreover, it does not need to have a functional group or the like to be aligned with fine particles. In order to obtain such a substrate, the surface of the substrate may be acid-treated before placing the fine particles. Acid treatment results in a flatter substrate surface.

In the manufacturing method of the present invention, the number of layers to be stacked can be freely set. The number of layers may be only one layer, 5 layers or more, or 10 layers or more. These can be adjusted by appropriately adjusting the time for emitting ultrasonic waves and the concentration of fine particles in the liquid placed on the substrate. As a result of adopting such means, the three-dimensional structure manufactured by the manufacturing method of the present invention can be a laminated body having a thickness of 0.2 to 100 μm, for example.
In the production method of the present invention, the fine particles can be filled so as to be closest packed. Furthermore, the three-dimensional structure manufactured by the manufacturing method of the present invention can have a defect ratio of, for example, 1% or less, and further 0.5% or less. In addition, the closest packing in the present invention is intended to include not only complete closest packing but also defective ones.
In addition, the method of the present invention has an advantage that it can be manufactured at a minimum if there is time to emit ultrasonic waves, for example, time to volatilize the liquid.

Moreover, in the manufacturing method of this invention, a three-dimensional structure can be made more stable by performing a physical process or a chemical process to the laminated body which laminated | stacked microparticles | fine-particles.
For example, by immersing the laminate in water, ethanol, or the like, the adsorptive power between the fine particles can be increased and the bond between the fine particles can be further increased.
Further, by coating the surface of the laminate with a metal oxide thin film (TiO ₂ or the like) or the like, a stronger one can be obtained. As a coating method in this case, a known method, for example, a method described in JP-A-9-241008, JP-A-10-249985, JP-A-2003-252609 or the like can be used. Further, in the production method of the present invention, one or more fine particle layers may be further provided on the surface coded with the metal oxide thin film.
Furthermore, it is also preferable to plasma-process the laminated body. As the plasma treatment, oxygen plasma treatment is preferable.

  The three-dimensional structure of the present invention can be preferably used as an optical material for optical filters, optical switches, waveguides, low threshold laser applications, and the like. In addition, when a metal oxide thin film is coated, it can be used for production of inverted opal, a carrier on which a catalyst is placed, and the like.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

Example 1
The glass substrate was immersed in a mixed solution of hydrogen peroxide (30% by volume) and concentrated sulfuric acid (70% by volume) for 8 hours, washed with ion-exchanged water, and then the substrate surface was air-dried with nitrogen gas. This substrate was placed on the bottom of the glass beaker, and the glass beaker was placed in a water bath of an ultrasonic generator (Daiwa Denshi Kogyo, 1510). 30 μl (2.72 wt%) of an aqueous solution in which polystyrene fine particles having a diameter of 548 nm (manufactured by Wako Pure Chemical Industries, Ltd.) were dispersed was dropped onto the substrate. After dropping, an ultrasonic wave (42 kHz) was generated and left for 1 hour. After 1 hour, water was evaporated, and a polystyrene fine particle layer was formed on the surface of the glass substrate. The obtained glass substrate was observed with a scanning electron microscope (SEM) (manufactured by Hitachi, Ltd., S-5200). The results are shown in FIG. 1 and FIG. Here, FIG. 2 shows a substrate surface obtained by observing FIG. 1 at a high magnification, FIG. 2B shows the substrate surface, and FIG. 2C shows a cross section of the fine particle layer.
As is clear from FIGS. 1 and 2, it was confirmed that the three-dimensional structures were laminated. In particular, as is clear from FIGS. 2 (b) and 2 (c), it was confirmed that the surface and the layer cross-section were filled most closely. Furthermore, when the defect ratio of the part enclosed with the white line in FIG. 1 was measured, it was 0.5% or less. Moreover, the thickness of the laminated body was 10 μm.

Example 2
Polystyrene fine particles having a diameter of 548 nm (manufactured by Wako Pure Chemical Industries, Ltd.) are dispersed in water so that the final concentration is 0.87 wt%, 1.74 wt%, 2.6 wt%, and 40 μl of these aqueous solutions are added. The solution was dropped on a substrate that had been treated in the same manner as in Example 1 and performed in the same manner as in Example 1. The result observed using SEM is shown in FIG. In FIG. 3, the content of fine particles is 0.87 wt%, 1.74 wt%, 2.6 wt% in the order of a, b, and c. As shown in FIG. 3a, it was confirmed that a laminate of 5 layers was formed at 0.87% by weight, 12 layers at 1.74% by weight, and 16 layers at 2.6% by weight.

Example 3
According to the conditions shown in Table 1 below, the others were carried out in the same manner as in Example 1. The results observed using SEM are shown in FIG.

  As is clear from FIG. 4, it was confirmed that the fine particles were suitably laminated at any particle size.

Example 4
Titanium butoxide was attached to the surface of the three-dimensional structure produced in Example 3c by a sol-gel reaction, and the surface was hydrolyzed to form a titanium oxide film. The results observed using SEM are shown in FIG.
Here, FIG. 5a shows the one before the thin film formation, and FIG. 5b shows the one after the thin film formation. Here, in FIG. 5b, it was recognized that fine particles exist more stably while there is no disorder of the laminated structure.

FIG. 1 shows an electron micrograph of the three-dimensional structure produced in Example 1 of the present application. FIG. 2 shows an enlarged view and a cross-sectional enlarged view of FIG. FIG. 3 shows an electron micrograph of the three-dimensional structure produced in Example 2 of the present application. FIG. 4 shows an electron micrograph of the three-dimensional structure produced in Example 3 of the present application. FIG. 5 shows an electron micrograph of the three-dimensional structure produced in Example 4 of the present application.

Claims (9)

A method for producing a three-dimensional structure, comprising a step of emitting ultrasonic waves to a substrate on which a liquid containing fine particles having a particle diameter of 100 nm to 2000 nm and a substantially uniform particle diameter is placed. The method for producing a three-dimensional structure according to claim 1, wherein the three-dimensional structure is closely packed with fine particles. The method for producing a three-dimensional structure according to claim 1 or 2, wherein the three-dimensional structure is a laminate of two or more fine particle layers. The method for producing a three-dimensional structure according to claim 1, wherein the fine particles are polystyrene. The method for producing a three-dimensional structure according to claim 1, wherein the fine particles are silica. The method for producing a three-dimensional structure according to any one of claims 1 to 5, wherein the three-dimensional structure is formed by laminating five or more fine particles. The manufacturing method of the three-dimensional structure in any one of Claims 1-6 whose defect ratio is 1% or less. Furthermore, the manufacturing method of the three-dimensional structure in any one of Claims 1-7 including the process of coating the surface of the laminated | stacked fine particle layer with a metal oxide thin film. A method of manufacturing a three-dimensional structure including a step of placing a liquid containing fine particles having a particle diameter of 100 to 2000 nm and a substantially uniform particle diameter on only a specific part of the substrate and emitting ultrasonic waves to the substrate .

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