Method for forming swelling pattern and base body having the same pattern

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The method for forming a bulge pattern obtained by the present invention is a completely new method for forming an uneven pattern that does not require an etching step or an embossing step by a mold, and is a metal oxide, an organic polymer, or an organic-inorganic substance on various substrates. A pattern such as a complex can be formed. The substrate with a bulge pattern of the present invention can be applied to technical fields such as printing, optical communication, display elements, and semiconductor elements. In particular, by selecting a transparent material, a microlens, an optical waveguide, a transparent electrode, and the like can be manufactured.

【0002】

[Previous technology]

Several methods are already known as a method for forming a surface uneven pattern on a substrate. A photolithography method is known in which a photoresist is formed on a substrate, exposed through a mask, and further etched after development to form an uneven pattern on the substrate. Further, a so-called 2P method is known in which a photocurable resin is applied on a substrate, a nickel stamper is pressed against the substrate, and the substrate is photocured and then released to form irregularities on the substrate. Further, there is known an embossing method in which a thermosetting coating film is formed on a substrate and thermosetting is performed while performing a mold press.

【0003】

Recently, it has been reported that a pattern is formed by utilizing the difference in wettability of a solid surface due to a self-assembled monolayer. In this method, a self-assembled monolayer is formed by using a surfactant having a hydrophilic functional group at the end of the alkyl chain, and a water-soluble polymer is selectively deposited on the self-assembled monolayer to form a surface uneven pattern. There is.

【0004】

For example, a self-organizing monomolecular film is formed on a silicon substrate using octadecylsiloxane, and polymethylmethacrylate, which is a water-soluble polymer, is selectively deposited on the self-structured monomolecular film, which acts as an etching mask and acts on the silicon substrate. It has been reported that a fine groove pattern can be formed by etching (Y. Xia et al., Journal of American Chemical Society, 177, 9576-9757 (1995).). In addition, a self-structured monomolecular film is formed on a silicon substrate using octadecylsiloxane, and an ethanol solution of tantalum pentoxide is applied onto this to cure it, and the difference in adhesive strength is used to selectively polish it. An example has been reported in which the tantalum oxide layer was peeled off to form a fine pattern of tantalum oxide on a silicon substrate (J. Aizenberg et al., Nature, 389, 495-498 (1999).).

【0005】

[Problems to be Solved by the Invention]

The above-mentioned conventional photolithography method is basically a method of selectively dissolving and removing a substrate or a film on the substrate by etching, and there is a limit to the shape that can be formed. For example, a bulge pattern such as a spherical lens or a lenticular lens is formed. It was impossible to do so, and it was not possible to impart a micron-order shape to the substrate, which is particularly necessary for printing and optical elements.

【0006】

On the other hand, in the 2P method and the embossing method, since a photocurable resin is generally used, the heat resistance of the obtained element is determined by the heat resistance of the resin, and there is a problem that high temperature stability is poor. Further, since the surface smoothness of the obtained pattern is determined by the surface smoothness of the mold used, it is very difficult to realize high surface smoothness.

【0007】

Regarding the method of selectively forming a film on the hydrophilic part by using the surface energy difference of the solid, which has been attracting attention recently, and forming an uneven pattern, the difference in contact angle between the water-repellent part and the hydrophilic part with water is also found. Since the temperature is at most 80 degrees, the selectivity is low, and a part of the film is formed not only in the hydrophilic part but also in the hydrophobic part, and because it cannot be thickly deposited on the hydrophilic part, a large bulge shape cannot be formed. There was a very big problem with. Therefore, it was not possible to manufacture a microlens array or a lenticular lens. Furthermore, in the conventional method of selectively forming a film on a hydrophilic portion by utilizing the surface energy difference of a solid to form an uneven pattern, a contact method such as microprinting is adopted for forming a self-assembled monolayer. Therefore, there is a limit to the fineness, that is, the resolution of the hydrophilic portion and the hydrophobic portion, and it is impossible to form a pattern at a pitch of several microns.

【0008】

[Means for solving problems]

In the present invention, in order to form a bulge pattern, the energy difference on the solid surface is used instead of utilizing the conventional actions of dissolution, photocuring, and thermosetting of a substance. That is, after forming a pattern consisting of a water-repellent portion and a hydrophilic portion on the substrate, a hydrophilic fluid or a hydrophobic fluid is applied to the substrate with the water-repellent / hydrophilic pattern, and the surface energy difference of the solid is utilized. A swelling pattern is formed on the substrate by selectively agglomerating into a hydrophilic portion or a hydrophobic portion and then solidifying the fluid.

【0009】

In the present invention, the difference in contact angle between the water-repellent portion and the hydrophilic portion of the pattern consisting of the water-repellent portion and the hydrophilic portion with respect to water is set to 80 degrees or more, thereby improving the selectivity of the deposited portion of the hydrophilic substance. ing. Further, the water-repellent portion is provided with a base layer having a fine uneven structure and an uppermost layer having water repellency so that the difference between the hydrophilic portion of the contact angle is 80 degrees or more.

【0010】

For the purpose of improving the resolution of the water-repellent / hydrophilic pattern, in the present invention, an intermediate layer having photodegradation activity is provided between the base layer and the uppermost layer, and the surface layer having water repellency by light irradiation through a photomask is provided. It enables selective decomposition and hydrophilicity.

【0011】

By using a liquid containing at least colloidal silica and water as the hydrophilic fluid in this study, the selectivity of deposition is improved and a large bulge shape can be formed. Further, by using a liquid in which fine particles having thermoplasticity are dispersed, a larger bulge pattern can be formed.

【0012】

BEST MODE FOR CARRYING OUT THE INVENTION

The difference in contact angle with respect to water of 80 degrees or more is that the water-repellent portion has a base layer having a fine uneven structure / an intermediate layer having photocatalytic activity / a surface layer having water repellency, and the hydrophilic portion has light on the water-repellent portion. This can be achieved by selectively irradiating and using the photodecomposition activity of the intermediate layer to decompose the water-repellent surface layer and thereby make it hydrophilic.

【0013】

The base layer having the fine concavo-convex structure can be provided by a method of directly roughening the surface of the substrate or a method of forming a film having a fine concavo-convex structure. Examples of the method of directly roughening the surface of the substrate include a method of mechanically roughening the surface of the substrate by polishing and the like, and a method of chemically roughening the surface of the substrate by etching and the like. As a method for forming a film having a fine concavo-convex structure, there is a method of forming an alumina gel film by using a sol-gel method and then treating the alumina gel film with warm water to form a petal-like concavo-convex structure. According to this method, a very fine uneven pattern can be formed, which is preferable.

【0014】

Examples of starting materials for producing an alumina film having a petal-like uneven structure by a sol-gel method include aluminum alkoxide, aluminum complex, aluminum nitrate, and aluminum sulfate. Of these, aluminum alkoxide is preferable. Examples of the alkoxide include aluminum ethoxyde, aluminum isopropoxide, aluminum-n-butoxide, aluminum-sec-butoxide, aluminum-ter-butoxide and the like. It is preferable to add a stabilizer if necessary.

【0015】

Examples of the stabilizer include β-diketone compounds such as acetylacetone, dipyrrobic methane, trifluoroacetylacetone, hexafluoroacetylacetone, benzoylacetone and dibenzoylmethane; methyl acetoacetate, ethyl acetoacetate and acetoacetate Β-ketoesters such as allyl, benzyl acetoacetone, acetoacetate-iso-propyl, acetoacetate-tert-butyl, acetoacetate-iso-butyl, acetoacetate-2-methoxyethyl, methyl 3-keto-n-valericate Compounds; Further, alkanolamines such as monoethanolamine, diethanolamine, triethanolamine and the like can be mentioned.

【0016】

If necessary, a diluting solvent is used as the coating solution. Diluting solvents include alcohols such as methanol, ethanol, butanol, ethylene glycol or ethylene glycol mono-n-propyl ether; various fats such as n-hexane, n-octane, cyclohexane, cyclopentane, cyclooctane. Group or alicyclic hydrocarbons; various aromatic hydrocarbons such as toluene, xylene, ethylbenzene; ethyl formate, ethyl acetate, n? Butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate , Various esters such as ethylene glycol monobutyl ether acetate; Various ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; Various ethers such as dimethoxyethane, tetrahydrofuran, dioxane, diisopropyl ether; chloroform, methylene chloride ,Carbon tetrachloride. Various chlorinated hydrocarbons such as tetrachloroethane; aprotic polar solvents such as N? Methylpyrrolidone, dimethylformamide, dimethylacetamide, ethylene carbonate and the like.

【0017】

In preparing the coating solution for forming the base layer used in the present invention, it is preferable to use alcohols among the various solvents described above from the viewpoint of solution stability. Further, when preparing a coating solution of aluminum alkoxide and a stabilizer, water may be added as necessary to partially hydrolyze the alkoxy group bonded to the metal. The amount of water added can be set relatively freely, but it is preferably about 1 to 4 per mole of aluminum alkoxide.

【0018】

A catalyst for promoting hydrolysis of alkoxy groups or promoting dehydration condensation reaction can be added to the coating solution containing aluminum alkoxide and a stabilizer. Typical catalysts include nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, ammonia and the like.

【0019】

The gel film of the aluminum compound produced by the above method may be dried at room temperature for about 30 minutes. It is also possible to dry at a higher temperature if necessary.

【0020】

Next, the gel film of the aluminum compound is immersed in warm water to form a thin film having a fine concavo-convex structure on the substrate. The temperature of the hot water is preferably 50 ° C to 100 ° C. The temperature of the hot water is determined in consideration of the heat resistance of the substrate and the like, but the lower the temperature, the longer it takes to completely form the fine concavo-convex structure.

【0021】

By immersing the substrate with the aluminum compound gel film in warm water, the surface layer surface of the aluminum compound gel film undergoes a glutinating action or the like. As a result, it becomes possible to have a surface layer surface in which peculiar petal-like shapes are randomly aggregated with peculiar minute pore-like voids, and it is possible to form desired peculiar voids and fine irregularities of shape. It can be made into a film that exerts its function and performance more. The hot water treatment time is about 5 minutes to 24 hours.

【0022】

Further, for example, drying is performed at about 100 ° C. or lower. Alternatively, after the drying, firing can be performed according to the heat resistance of the substrate. As a result of observation with a high-resolution transmission electron microscope, it is known that the uneven structure formed by the hot water treatment is mainly caused by the formation of the boehmite layer. The film thickness of the petal-shaped transparent alumina film can be arbitrarily set, but is preferably about 50 nanometers or more and 400 nanometers or less.

【0023】

The intermediate layer having photocatalytic activity is preferably a titanium compound or a complex containing a titanium compound because the titanium compound has high catalytic activity. As the titanium compound, in addition to amorphous, anatase-type and rutile-type titania, a complex such as titanium acetylacetonato and a hydrolyzed polycondensate thereof are preferable.

【0024】

Examples of starting materials in the preparation of a thiania film by a sol-gel method include titanium alkoxide, a titanium complex, and titanium sulfate. Of these, titanium alkoxide is preferable. Examples of the alkoxide include isopropoxide, titanium-n-butoxide, titanium-sec-butoxide, titanium-ter-butoxide and the like. If necessary, it is preferable to add stabilizers such as the above-mentioned β-diketone compounds, β-ketoester compounds and alkanolamines.

【0025】

If necessary, a diluting solvent is used as the coating solution. Diluting solvents include alcohols, various aliphatic or alicyclic hydrocarbons, various esters, various ketones, various ethers, various chlorinated hydrocarbons and aprotic polarities. Examples include solvents.

【0026】

In preparing the coating solution for forming the intermediate layer used in the present invention, it is preferable to use alcohols among the various solvents described above from the viewpoint of solution stability. Further, when preparing a coating solution of titanium alkoxide and a stabilizer, water may be added as necessary to partially hydrolyze the alkoxy group bonded to the metal. The amount of water added can be set relatively freely, but it is preferably about 1 to 4 per mole of titanium alkoxide.

【0027】

A catalyst for promoting hydrolysis of alkoxy groups or promoting dehydration condensation reaction can be added to the coating solution containing titanium alkoxide and a stabilizer. The gel film of the aluminum compound produced by the above method may be dried at room temperature for about 30 minutes. Further, in order to realize high photocatalytic activity, it is preferable to perform heat treatment at 300 ° C. or higher to generate anatase crystals.

【0028】

Examples of the composite system intermediate layer containing a titanium compound include composite oxides such as titania-silica, titania-alumina, and titania-zirconia.

【0029】

The film thickness of the intermediate layer having photodecomposition activity can be arbitrarily set within a range that does not impair the shape of the fine surface structure of the underlying layer, but is preferably several nanometers to several hundred nanometers.

【0030】

The water-repellent surface layer preferably uses an organosilane compound as one of the starting materials. A water-repellent surface layer using an organosilane compound as a starting material can be formed by a sol-gel method, a vapor deposition method, or the like.

【0031】

Examples of the above-mentioned organosilane compound include an organosilane compound having at least one hydrolyzable group bonded to a silicon atom and at least one organic group bonded to a silicon atom, and various silicate compounds. In such an organosilane compound, the hydrolyzable group bonded to the silicon atom is hydrolyzed such as an alkoxy group, a substituted alkoxy group, an alkenyloxy group, an iminooxy group, an aryloxy group, an aralkyloxy group, a halogen atom and a hydrogen atom. It refers to a group that forms a hydroxyl group bonded to a silicon atom, that is, a silanol group. Typical organic groups bonded to silicon atoms include alkyl groups, substituted alkyl groups to which various substituents are bonded via silicon-carbon bonds, cycloalkyl groups, aryl groups, aralkyl groups, and alkenyl groups. Examples include various organic groups such as groups.

【0032】

Among the above-mentioned organic groups, typical alkyl groups have 1-30 carbon atoms such as methyl group, ethyl group, n-butyl group, iso-butyl group, n-octyl group and n-dodecyl group. Alkyl groups can be mentioned. Representative of substituent alkyl groups are 3-substituted propyl groups such as 3-glycidoxypropyl group, 3- (meth) acryloyloxypropyl group; 3,3,3, -trifluoropropyl group, 4 , 4,4-Trifluorobutyl group, CF3 (CF2) 2CH2CH2-, CF3 (CF2) 3CH2CH2-, CF3 (CF2) 7CH2CH2-, CF3 (CF2) 9CH2CH2-, CF3 (CF2) 11CH2CH2-, CF3 (CF2) 13CH2CH2 -, Alkyl groups substituted with various fluorine atoms such as CF3 (CF2) 15CH2CH2-, CF3 (CF2) 17CH2CH2-, CF3 (CF2) 21CH2CH2-, CF3 (CF2) 25CH2CH2-, CF3 (CF2) 27CH2CH2- Be done.

【0033】

Among the organosilane compounds containing at least one hydrolyzable group and at least one organic group as described above, methyl is a typical example of an organosilane compound containing an alkoxy group or a substituted alkoxy group as a hydrolyzable group. Trimethoxysilane, methyltriethoxysilane, n-octyltrimethoxysilane, n-dodecyltrimethoxysilane, n-octadecyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltri-n-butoxysilane, n-propyl Trimethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-butoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri-n- Butoxysilane, vinyltris (2? methoxyethoxy) silane or allyltrimethoxysilane, 2-trimethoxysilylethyl vinyl ether, 2-triethoxysilylethyl vinyl ether, 3-trimethoxysilylpropyl vinyl ether, 3-triethoxysilylpropyl vinyl ether, 3 -(Meta) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 4,4,4-Trifluorobutyltrimethoxysilane, CF3 (CF2) 2CH2CH2-Si (OCH3) 3, CF3 (CF2) 3CH2CH2-Si (OCH3) 3, CF3 (CF2) 7CH2CH2-Si (OCH3) 3, CF3 (CF2) 9CH2CH2 -Si (OCH3) 3, CF3 (CF2) 11CH2CH2-Si (OCH3) 3, CF3 (CF2) 13CH2CH2-Si (OCH3) 3, CF3 (CF2) 15CH2CH2-Si (OCH3) 3, CF3 (CF2) 17CH2CH2-Si Various organotrialkoxysilanes such as (OCH3) 3, CF3 (CF2) 21CH2CH2-Si (OCH3) 3, CF3 (CF2) 25CH2CH2-Si (OCH3) 3, CF3 (CF2) 27CH2CH2-Si (OCH3) are examples. Can be mentioned.

【0034】

If necessary, a diluting solvent is used as the coating solution. Diluting solvents include alcohols, various aliphatic or alicyclic hydrocarbons, various esters, various ketones, various ethers, various chlorinated hydrocarbons and aprotic polarities. Examples include solvents.

【0035】

In preparing the coating solution for forming the surface layer used in the present invention, it is preferable to use alcohols among the various solvents described above from the viewpoint of solution stability. Further, when preparing a coating solution containing organosilane, water may be added as necessary to partially hydrolyze the functional group bonded to the metal. The amount of water added can be set relatively freely, but it is preferably about 1 to 4 per mole of organosilane.

【0036】

A catalyst for promoting hydrolysis of alkoxy groups or promoting dehydration condensation reaction can be added to the coating solution containing organoalkoxysilane. The surface layer obtained from the coating solution containing organoalkoxysilane is dried at room temperature or heat-treated at 400 ° C. or lower, and the heat treatment temperature is preferably set in consideration of the heat resistance of the substrate and the like.

【0037】

As the composite system surface layer containing an organoalkoxysilane, a composite system such as an organoalkoxysilane and a tetraalkoxysilane can also be used. The film thickness of the water-repellent surface layer can be arbitrarily set as long as the shapes of the fine surface structures of the base layer and the intermediate layer are not impaired. Specifically, it is preferably about several nanometers to 100 nanometers.

【0038】

Examples of the solution coating method for forming the base layer, the intermediate layer, and the surface layer using the sol-gel method include a dipping method, a spin coating method, a spray method, a printing method, a flow coating method, and a combination thereof. , Known coating means can be appropriately adopted. The film thickness can be controlled by changing the pulling speed in the dipping method, the substrate rotation speed in the spin coating method, and the like, and changing the concentration of the coating solution.

【0039】

The water-repellent / hydrophilic patterned substrate can be produced by selectively decomposing an organic functional group having water repellency on the outermost surface and making it hydrophilic by utilizing the photodecomposition action of the intermediate layer. The difference in contact angle between the water-repellent portion and the hydrophilic portion is preferably 80 degrees or more in order to improve the selectivity and resolution of the substance to be deposited. Further, it is more preferable to set the temperature to 100 degrees or higher.

【0040】

More specifically, an alumina layer having a petal-like microstructure as a base layer having a fine concavo-convex structure / a titanium oxide layer as an intermediate layer having photodecomposition activity / a fluoroalkylalkoxysilane as a surface layer having water repellency. The surface having a three-layer structure of a hydrolysis-polycondensate layer becomes a so-called superhydrophobic state with a contact angle with water of about 160 degrees due to the shape effect of the underlying layer and the hydrophobicity of the outermost surface.

【0041】

Light irradiation is performed by irradiating the surface of a superhydrophobic state with a contact angle with water of 160 degrees with ultraviolet rays via a photomask and decomposing the fluoroalkyl group in the uppermost layer by the photodecomposition effect of titania in the intermediate layer. The contact angle of the part becomes about 5 degrees and becomes superhydrophilic. As a result, the contact angle difference between the superhydrophobic part and the superhydrophilic part becomes about 155 degrees, which means that a very large surface energy difference is given to the solid surface.

【0042】

In the conventional water-repellent / hydrophilic technology, the difference in contact angle between the water-repellent portion and the hydrophilic portion is about 80 degrees at the most, and in order to achieve 80 degrees or more, the fine unevenness of the base layer as in the present invention. The shape effect of the tissue is essential.

【0043】

As the photomask used in the present invention, various photomasks can be used depending on the intended purpose. For example, a metal mesh mask having an opening in a metal such as gold, copper, stainless steel, chrome, titanium, or aluminum can be used. Furthermore, in order to form fine patterns on the order of 10 microns to submicrons, a photomask substrate is formed by forming a chromium film on a material that transmits ultraviolet rays, such as silica glass, and using photolithography-etching technology to provide fine openings. Can be used.

【0044】

In the present invention, an aqueous solution, a sol, a fine particle dispersion slurry, or a melt can be used as the hydrophilic fluid to be deposited on the hydrophilic portion.

【0045】

Examples of the aqueous solution include aqueous solutions of salts, water-soluble polymers, dyes and the like. Examples of the sol include the above-mentioned various sol such as silica sol, titania sol, alumina sol, antimony sol, zirconia sol, indium oxide sol, and silica sol which has been surface-modified with an organic functional group such as a methyl group or an ethyl group. Examples of the fine particle dispersion slurry include dispersion slurry of metal oxides, metal halides, metal sulfides, metal nitrides, metal carbides, insoluble salts, minerals, pigments and the like. Specifically, silica, titania, alumina, antimony, zirconia, apatite, indium oxide, indium tin oxide, superconducting fine particles, silver chloride, cadmium sulfide, phenylsilsesquioxane fine particles, methylsilsesquioxane fine particles, inorganic pigments. And organic pigment slurries can be widely used. Examples of the melt include organic-inorganic composites such as low-melting glass, organic polymers, phenylsilsesquioxane, and benzylsilsesquioxane.

【0046】

If a hydrophilic fluid containing an organic polymer or a transparent metal oxide is used to form a large bulge shape pattern by utilizing a large difference in solid surface energy according to the present invention, it is possible to collect light from a microlens, a waveguide, etc. A micro optical element having a wave or combined wave function can be manufactured on a substrate.

【0047】

By forming a bulge pattern using a hydrophilic fluid containing an organic-inorganic composite, an organic polymer, a metal oxide, a transparent conductive substance, a pigment, etc., a concave plate or a letterpress plate useful in the printing field can be produced. In addition, transparent electrodes and color filters in the liquid crystal field can be manufactured.

【0048】

If water-based colloidal silica is used as the hydrophilic fluid, a transparent bulge pattern can be obtained, so that a microlens array or an optical waveguide can be produced.

【0049】

The particle size of colloidal silica used in the present invention is preferably in the range of 5 nanometers to 100 nanometers. In particular, when forming a pattern having a large bulge, it is preferably about 50 nanometers. Since the swelling of colloidal silica becomes smaller as the solvent evaporates, it is preferable to set the weight of colloidal silica in the solution higher. Specifically, it is preferably 20% by weight or more, more preferably 70% by weight or more.

【0050】

It is preferable to add a surfactant to the colloidal silica for the purpose of preventing cracks in the formed swelling pattern and improving the storage stability of the solution. As the surfactant, polyethylene glycol, ethylene glycol or the like can be used. The amount of polyethylene glycol or ethylene glycol added is preferably in the range of 0.1 to 5 by weight with respect to colloidal silica. Furthermore, the weight ratio is preferably about 1. Further, it is preferable to add tetraalkoxysilane for the purpose of improving the transparency of the formed bulge pattern and preventing cracks. The amount of tetraalkoxysilane added is preferably in the range of 0.3 to 3 by weight with respect to colloidal silica. Furthermore, the weight ratio is preferably about 1.

【0051】

When a liquid in which thermoplastic fine particles are dispersed is used as the hydrophilic fluid, a transparent bulge pattern can be produced by heating and cooling the fine particles deposited on the hydrophilic portion to a temperature at which viscous flow occurs. Organosylsesquioxane can be used as the fine particles that cause viscous flow by heating, in addition to polystyrene-based thermoplastic organic polymers.

【0052】

Examples of the substrate forming the bulge pattern include various glass materials, metal substrates, inorganic substrates, plastic substrates, paper, wood-based substrates, and the like. In particular, when applied to optical communication, display elements, etc., glass or silicon is often used as a base material. When applied as a letterpress to the printing field, foils such as galvanized iron, aluminum, and brass are often used. It is also possible to select a plastic base material, paper, or wood-based base material having low heat resistance due to the feature that the bulge pattern of the present invention can be formed at a low temperature in the whole process.

【0053】

Examples of the glass material include non-alkali glass such as silica glass, borosilicate glass and aluminosilicate glass, alkali borosilicate glass, alkali aluminosilicate glass and soda lime silica glass.

【0054】

Typical metal substrates include various metals such as iron, nickel, aluminum, chromium, zinc, tin and copper; alloys of various metals such as stainless steel and brass.

【0055】

Typical plastic substrates are films and moldings of thermoplastic resins such as polyethylene terephthalate, polypropylene, polystyrene, polycarbonate, polymethylmethacrylate, ABS resin, polyphenylene oxide, polyurethane, polyethylene, polyvinyl chloride; unsaturated. Examples thereof include crosslinked films obtained from various thermosetting resins such as polyester resins, phenol resins, crosslinked polyurethanes, crosslinked acrylic resins, and crosslinked saturated polyester resins, and crosslinked molded products.

【0056】

Example 1 A quartz glass substrate having a size of about 25 mm × 25 mm and a thickness of about 1 mm was washed, dried, and then used as a coating substrate.

【0057】

Aluminum-sec-butoxide [Al (O-sec-Bu)₃] To 2 propanol [IPA] and ethyl acetoacetate [EAcAc], and further 0.01M dilute nitric acid [H].₂O] and [IPA] were added. Here, the molar ratio of the solution is Al (O-sec-Bu).₃: IPA: EAcAc: H₂The ratio was O = 1: 20: 1: 1. Stir this at room temperature for about 1 hour and Al₂O₃A coating solution 1 which is a sol was prepared.

【0058】

After immersing the quartz glass substrate for coating in the coating liquid, a coating film was formed on the surface of the coating substrate by a dipping method (pulling speed of about 1 mm / sec).

【0059】

Subsequently, it was heat-treated at 500 ° C. for 30 minutes to coat a transparent amorphous alumina film. Next, a hot water treatment of immersing in warm water at about 100 ° C. for a predetermined time was performed, and the mixture was dried again at room temperature. The obtained thin film showed high transmittance in the visible region, and the film thickness was about 200 nanometers. Scanning electron microscope (SEM) observation and atomic force microscope (AFM) observation were carried out on the transparent alumina base layer of the obtained quartz with a transparent alumina thin film on the lath substrate. It was found that the center line average roughness Ra value of the fine uneven structure was 19 (nm).

【0060】

Next, titanium-n-butoxide [Ti (On-Bu)₃] Is added to ethanol [EtOH] and ethyl acetoacetate [EAcAc], and 0.01M dilute nitric acid [H] is added.₂O] and [EtOH] were added. Here, the molar ratio of the solution is Ti (On-Bu).₃: EtOH: EAcAc: H₂The ratio was O = 1: 180: 1: 1. This was stirred at room temperature for about 1 hour to prepare a coating liquid 2 which is a TiO2 sol.

【0061】

A TiO2 gel film is formed as an intermediate layer by a dipping method on a quartz glass substrate with an alumina film having a fine concavo-convex structure using the coating solution 2, and heat-treated at 500 ° C. for 30 minutes to obtain a film thickness of about 5. A nanometer transparent anatase-type titania film was formed. It was confirmed that the center line average roughness Ra value of the titania intermediate layer was 19 (nm), and the surface roughness did not change.

【0062】

Heptadecafluorodecyltrimethoxysilane (FAS) is formed by vapor deposition as a surface layer on a quartz glass substrate with an alumina base layer / transparent anatase type titania intermediate layer having the fine uneven structure, and the contact angle of water is measured. And the light transmittance was measured. It was found that it exhibits a superhydrophobic state with a contact angle of 160 ° or more and high transparency with a transmittance of 90% or more in the visible range.

【0063】

From a distance of 5 cm using a 250 W ultra-high pressure mercury lamp "UIS? 25102" (wavelength of irradiation light: 250-450 nm) manufactured by Ushio, Inc. on a substrate having a three-layer film structure prepared in this way. , UV irradiation was performed for 30 minutes through various photomasks. The contact angle of the film with water before irradiation with ultraviolet rays was 160 degrees, but that after irradiation was 5 degrees or less, confirming that the film was highly hydrophilic.

【0064】

When a copper mesh is used as the photomask, a superhydrophobic / superhydrophilic pattern can be formed in square and staggered arrangements with pitches of 100 microns, 80 microns, 60 microns, 40 microns, 20 microns, and 10 microns. all right. The difference in contact angle between the superhydrophobic part and the superhydrophilic part was about 155 degrees.

【0065】

It was found that when a quartz glass substrate with a chrome film was used as the photomask, a pattern for a lenticular lens or a stripe pattern for an optical waveguide of an arbitrary width of 30 to 2 microns could be formed. It was also found that superhydrophobic / superhydrophilic patterns can be formed in square and staggered arrangements with a pitch of 10 to 1 micron.

【0066】

A square-arranged superhydrophobic / superhydrophilic patterned substrate with a pitch of approximately 50 microns and an opening diameter of approximately 20 microns and a striped superhydrophobic / superhydrophilic patterned substrate with a pitch of approximately 100 microns and an opening diameter of approximately 5 microns. Using it, we made a prototype of a microlens array and an optical waveguide. Figure 1 shows a conceptual diagram of the cross section of the prototype microlens.

【0067】

Polyethylene glycol having an average molecular weight of 600 was added by weight to colloidal silica having a silica content of about 20% by weight and a particle size of about 50 nanometers, and the mixture was stirred at room temperature for 30 minutes. Next, dilute nitric acid containing a hydrolyzate of tetramethoxysilane was added in a weight ratio of 1/8 with respect to colloidal silica, and the mixture was further stirred at room temperature for 30 minutes to prepare a colloidal silica-based solution 4 for forming a swelling pattern. did.

【0068】

The above solution 4 is mixed with a substrate having a square arrangement of superhydrophobic / superhydrophilic patterns having an opening diameter of about 20 microns and a stripe having a pitch of about 100 microns and an opening width of about 5 microns. A predetermined amount was dropped onto the patterned substrate. The solution 4 selectively aggregated in the hydrophilic pattern portion and formed a droplet-like spherical surface by surface tension. After that, it was found that the curvature of the droplet-like spherical surface became smaller as the solvent evaporated, but a swelling pattern was formed by the solidification of the solution.

【0069】

After drying, the shape of the bulge pattern was evaluated. As a result, a hemispherical bulge pattern with a height of about 4 microns was found in the hydrophilic part of the square matrix with a diameter of about 20 microns, and a top was found on the hydrophilic part of the stripe with a width of about 5 microns. It was found that a cylindrical bulge pattern with a height of about 2 microns was formed. It was also found that colloidal silica was not deposited on the superhydrophobic portion at all, and extremely excellent selective bulging shape patterning could be realized due to the large energy difference on the solid surface.

【0070】

The hemispherical bulge pattern with a height of about 4 microns and the cylindrical bulge pattern with a top height of about 2 microns both show high transparency and excellent light collection properties, and have focal lengths of 60 microns and 20 microns (in air), respectively. Was found to have.

【0071】

Example 2 Same as Example 1, superhydrophobic / superhydrophilic patterned substrate with a square arrangement with a pitch of about 50 microns and an opening diameter of about 20 microns and superhydrophobic stripes with a pitch of about 100 microns and an opening width of about 5 microns. A swelling pattern was formed on the substrate with a water / superhydrophilic pattern by an organic-inorganic composite having thermoplasticity.

【0072】

Using benzyltriethoxysilane as a starting material, hydrolysis was carried out under dilute hydrochloric acid conditions, and then benzylsilsesquioxane particles were prepared under ammonia conditions. The fine particle dispersion aqueous solution 5 was added dropwise to the substrate. The solution 5 selectively aggregated in the hydrophilic pattern portion and formed a droplet-like spherical surface by surface tension. After that, it was found that the curvature of the droplet-like spherical surface became smaller as the solvent evaporated, but benzyl silsesquioxane particles were deposited on the hydrophilic portion due to the solidification of the solution.

【0073】

When this is heated at 100 ° C, the benzyl silsesquioxane particles melt and form spherical surfaces and curved surfaces due to the surface tension of the melt, and when cooled, the height of the square-arranged hydrophilic part with a diameter of about 20 microns. It was found that a hemispherical bulge pattern of about 6 microns was formed, and a cylindrical bulge pattern with a top height of about 3 microns was formed in the hydrophilic part of the stripe with a width of about 5 microns. In addition, benzyl silsesquioxane is not deposited on the superhydrophobic part at all, and extremely excellent selectivity is realized by the large energy difference on the solid surface, and further, a large bulge shape patterning is possible by the surface tension of the melt. I understood.

【0074】

Example 3 Exactly the same bulging micropattern molding as in Examples 1 and 2 was performed on a silicon substrate. As a result, a swelling pattern can be formed regardless of the type of substrate by providing three layers of an alumina base layer having a fine uneven structure, a transparent anatase type titania intermediate layer, and a heptadecafluorodecyltrimethoxysilane (FAS) surface layer. I understood.

【0075】

Example 4 Exactly the same bulging micropattern molding as in Examples 1 and 2 was carried out using a polycarbonate substrate as an example of a resin substrate. Polycarbonate has lower heat resistance than quartz glass and silicon, so it cannot be heat-treated at a high temperature. Therefore, the alumina base layer having a fine concavo-convex structure was prepared by directly treating the alumina gel film with boiling water without high-temperature heat treatment. The transparent anatase-type titania intermediate layer was formed by using a diluted anatase sol. As a result, it was found that the swelling pattern can be formed on the resin substrate by providing the three layers.

【0076】

Example 5 Using an aqueous solution of polymethylmethacrylate containing iron oxide fine particles as a red pigment on a substrate with a superhydrophobic / superhydrophilic pattern in a square arrangement with a pitch of about 50 microns and an opening diameter of about 20 microns, which is the same as in Example 1. , A prototype of a red filter was made. As a result, it was found that the pattern of the coloring filter can be formed with good selectivity by this method.

【0077】

Comparative example 1 An experiment of a swelling pattern was carried out under the same conditions as in Example 1 without providing an alumina base layer having a fine concavo-convex structure. As a result, the contact angles of water in the water-repellent portion and the hydrophilic portion were 95 degrees and 20 degrees, respectively. As a result, the contact angle difference between the water-repellent portion and the hydrophilic portion was about 75 degrees. When the colloidal silica-based solution 4 for forming a swelling pattern was dropped, it expanded to a part of the water-repellent portion, and selective liquid aggregation could not be achieved. The tendency became remarkable when the dropping amount was increased in order to increase the swelling.

【0078】

Comparative example 2 A swelling pattern was formed by using a benzyl silsesquioxane particle dispersion aqueous solution 5 instead of the colloidal silica-based solution 4 used in Comparative Example 1, but the liquid remained in the water-repellent portion and high definition. Pattern was not obtained.

【0079】

Comparative example 3 An experiment of a swelling pattern was carried out using an ethanol sol obtained by hydrolyzing tetraethoxysilane instead of colloidal silica in Example 1, but swelling could not be formed due to large shrinkage due to evaporation, cracks were generated, and selectivity was improved. It caused a serious problem such as no.

【0080】

[Effect of the invention]

As described above, in order to form the swelling pattern, the present invention utilizes the energy difference of the solid surface instead of utilizing the conventional actions of dissolution, photocuring and thermosetting of the substance. That is, after forming a pattern consisting of a water-repellent portion and a hydrophilic portion on the substrate, a hydrophilic fluid or a hydrophobic fluid is applied to the substrate with the water-repellent / hydrophilic pattern to utilize a particularly large surface energy difference of a solid. Then, the fluid is selectively agglomerated into the hydrophilic portion or the hydrophobic portion, and then the fluid is solidified to form a swelling pattern on the substrate.

【0081】

Specifically, by setting the contact angle difference between the water-repellent portion and the hydrophilic portion of the pattern consisting of the water-repellent portion and the hydrophilic portion to 80 degrees or more, the selectivity of the deposited portion of the hydrophilic substance is improved. I'm letting you. Further, the water-repellent portion is provided with a base layer having a fine uneven structure and an uppermost layer having water repellency so that the difference between the hydrophilic portion of the contact angle is 80 degrees or more.

【0082】

For the purpose of improving the resolution of the water-repellent / hydrophilic pattern, in the present invention, an intermediate layer having photodegradation activity is provided between the base layer and the uppermost layer, and the surface layer having water repellency by light irradiation through a photomask is provided. It enables high definition by selective decomposition and hydrophilicization.

【0083】

In this study, a substrate having an alumina layer / titanium compound layer / organosilane hydrolysis-polycondensate layer having a petal-like microstructure was used as a superhydrophobic / superhydrophilic pattern substrate, and colloidal silica was used as a hydrophilic fluid. By using a liquid containing at least water and water, the selectivity of deposition is improved and a large bulge shape can be formed. Further, by using a liquid in which fine particles having thermoplasticity are dispersed, a larger bulge pattern can be formed.

【0084】

The method for forming a bulge pattern obtained by the present invention is a completely new method for forming an uneven pattern that does not require an etching step or an embossing step by a mold, and is a metal oxide, an organic polymer, or an organic-inorganic substance on various substrates. A pattern such as a complex can be formed. The substrate with a bulge pattern of the present invention can be applied to technical fields such as printing, optical communication, display elements, and semiconductor elements. In particular, by selecting a transparent material, a microlens, an optical waveguide, a transparent electrode, and the like can be manufactured.

[Simple explanation of drawings]

[Figure 1]

The schematic diagram of the cross section of the bulge pattern produced in Example 1. 1a: A bulging microlens in which colloidal silica is aggregated and solidified 1b: Glass substrate 1c: Alumina base layer with fine uneven structure 1d: Transparent anatase-type titania intermediate layer 1e: Heptadecafluorodecyltrimethoxysilane surface layer