JP2017100358A - Substrate with superhydrophilic coating film, and coating liquid and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a substrate with a hydrophilic coating film, which maintains excellent hydrophilicity for a long term, has abrasion resistance, and is excellent in adhesion strength between particles with each other in the coating film and between the coating film and the substrate; and a production method of the substrate.SOLUTION: Provided is a substrate with a superhydrophilic coating film, in which the superhydrophilic film on the substrate surface comprises: a particle layer containing inorganic oxide particles; and an adhesive layer included in a space between the inorganic oxide particles and a space between the inorganic oxide particles and the substrate, where a surface of the inorganic oxide particle is hydrophilic and has an uneven structure where an upper part of the inorganic oxide particle is exposed from the adhesive layer. The substrate with a superhydrophilic coating film is produced by: preparing a coating liquid for forming a coating film by mixing a dispersion of inorganic oxide particles and a suspension of resin emulsion particles; forming a particle layer where the resin emulsion particles are included in a space between the inorganic oxide particles by coating the coating liquid, and forming an adhesive layer by breaking the resin emulsion particles.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a substrate with a coating excellent in hydrophilicity and a method for producing the same, and a substrate with a superhydrophilic coating having a coating excellent in hydrophilicity suitable for water treatment and other uses on the substrate, The present invention relates to the coating liquid and the manufacturing method.

  As for the hydrophilic coating, it is known to provide a hydrophilic coating to prevent, for example, dew condensation that occurs on the surface of automobiles and buildings, such as window glass and mirror surfaces, and (i) a dispersion of titania particles and silica particles. There are known coatings obtained by coating and baking, and (b) coatings obtained by applying and baking a mixed solution of a silica precursor and titania sol. However, since the coating film (a) has no binder and has low bonding strength with the substrate due to the absence of a binder, the coating film (b) has titania particles covered with a silica precursor and hardly exhibits hydrophilicity as a photocatalyst. It has been pointed out that it is difficult to maintain the sex for a long time (Patent Document 1).

  Further, the hydrophilic film is used as an antifouling material, (c) a hydrophilic film containing photocatalyst fine particles such as titanium oxide, (d) a siliceous film formed by a sol-gel method, (e) silicon and Known are hydrophilic coatings containing a complex oxide of zirconium and water, or a mixture of silicon oxide and zirconium oxide and water. However, the coating film (c) is not sufficiently hydrophilic because the binder covers the particles, and the coating film (d) does not develop a siloxane bond due to low temperature treatment, and the water resistance is weak. It has been pointed out that the adhesion strength on the substrate is not sufficient (Patent Document 2).

  Furthermore, a substrate with a hydrophilic film suitable for water treatment is known. Patent Document 3 discloses a base material and a hydrophilic transparent film on the surface of the base material, wherein the hydrophilic transparent film includes an inorganic oxide fine particle layer containing inorganic oxide fine particles and a binder layer on the inorganic oxide fine particle layer. The surface of the hydrophilic transparent coating has a concavo-convex structure, the average height of the convex portions is in the range of 30 to 500 nm, and the average convex portion distance (pitch width) is in the range of 50 to 1000 nm. A substrate with a hydrophilic transparent coating is described, wherein the contact angle with water is 20 ° or less.

  The substrate with a hydrophilic film described in Patent Document 3 is excellent in adhesion to the substrate, transparency, hardness, scratch resistance, abrasion resistance, haze, etc., for example, on a glass substrate. When the coating is provided, water drops dripped onto the coating are quickly diffused on the coating surface to maintain a transparent state, and when the coating is provided on an RO membrane or nonwoven fabric, fouling is suppressed. And has advantages such as being suitable for water treatment.

  On the other hand, since the base material with a hydrophilic film of patent document 3 is provided with the binder layer on the inorganic oxide fine particle layer, the concavo-convex structure on the surface of the film formed by the inorganic oxide fine particle is covered with the bond layer. For this reason, the effect of the uneven structure may not be sufficiently exhibited. In addition, it is necessary to apply a bonding layer after forming a particle layer of inorganic oxide fine particles. Further, after forming a base bonding layer on a substrate, a particle layer is formed, and a surface is formed on the particle layer. In the case of laminating the bonding layer, there is a problem that the number of steps of applying the bonding layer increases and the cost is high.

JP 2003-176426 A JP 2007-161770 A JP2015-136669A

  The present invention solves the problems of the conventional hydrophilic coatings of the above (a) to (e), and the substrate with a hydrophilic coating of Patent Document 3 has a concavo-convex structure of the coating by an upper binding layer or the like. The effect of the concavo-convex structure can be sufficiently exhibited without being covered, and the manufacturing process is further simplified and the adhesion strength of the coating is increased.According to the present invention, excellent hydrophilicity is maintained for a long period of time, Provided are a substrate with a hydrophilic coating that has wear resistance and excellent adhesion strength between particles in the coating and between the coating and the substrate, and a coating solution and a production method therefor.

The substrate with a superhydrophilic film of the present invention has the following configuration.
[1] A hydrophilic substrate having a superhydrophilic coating on the substrate surface, wherein the coating includes a particle layer containing inorganic oxide particles, a gap between the inorganic oxide particles, and the inorganic oxide particles. It is composed of an adhesive layer interposed in the gap of the base material, the surface of the inorganic oxide particles is hydrophilic, and has an uneven structure in which the upper part of the inorganic oxide particles is exposed from the adhesive layer on the surface of the coating A substrate with a super-hydrophilic coating characterized by
[2] The average particle diameter (D _P ) of the inorganic oxide particles is 20 to 600 nm, the film thickness (U _F ) of the adhesive layer is 6 to 400 nm, and the average particle diameter (D a ratio _{(U F} / _{D P)} is 1 / 3-2 / 3 of the thickness of the adhesive layer _{(U F)} for _P), 1/3 of the average particle diameter of the inorganic oxide particles _{(D P)} ~ 2/3 is exposed from the adhesive layer, The substrate with a superhydrophilic film as described in [1] above.
[3] the average height of the projections of the uneven structure of the hydrophilic coating surface _{(T F)} is in the range of 10 to 300 nm, the average distance between convex portions (pitch) _{(W F)} is in the range of 1~1000nm The substrate with a superhydrophilic film according to any one of [1] or [2], wherein the substrate has a superhydrophilic film.
[4] The substrate with super hydrophilic coating according to any one of [1] to [3] above, wherein the hydrophilic coating has a thickness of 20 nm to 700 nm.
[5] The superhydrophilic coating film according to any one of [1] to [4] above, wherein the inorganic oxide particles are spherical, plate-shaped, confetti-shaped, or sunflower-shaped. Base material.
[6] The substrate with a superhydrophilic film as described in [5] above, wherein the inorganic oxide particles are spherical, plate-like, confetti-like, or sunflower-like and porous.
[7] The inorganic oxide particles are sunflower-like particles composed of inorganic oxide substrate particles and inorganic oxide fine particles covering the surface of the substrate particles, and the inorganic oxide particle surfaces are finely divided by the fine particles. The substrate with a superhydrophilic film according to any one of [1] to [4] above, which has irregularities.
[8] The inorganic oxide particles have fine irregularities on the surface, and the average height of convex portions (T _FF ) of the fine irregularities is in the range of 0.5 to 10 nm. The substrate with a superhydrophilic film according to any one of [1] to [7] above, wherein an average distance (pitch width) (W _FF ) is in the range of 1 to 30 nm.
[9] The surface of the inorganic oxide particles is modified with a hydrophilic group by a hydrolyzable organosilicon compound represented by the formula of SiX ₄ (where X is an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, a halogen, or hydrogen). The substrate with a superhydrophilic film as described in any one of [1] to [8] above, wherein
[10] The substrate with a superhydrophilic film according to any one of [1] to [9], wherein a contact angle with water is 10 ° or less.
[11] The inorganic oxide particles are SiO ₂ , Al ₂ O ₃ , Sb ₂ O ₅ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , CeO ₂ , AgO, CuO, Cu ₂ O, and a composite oxide thereof. The substrate with a superhydrophilic film according to any one of [1] to [10] above, which is at least one selected from a mixture.
[12] The adhesive layer is an emulsion resin, which is an ester resin, polycarbonate resin, amide resin, imide resin, polyphenylene oxide resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, silicone The superhydrophilic film according to any one of [1] to [11] above, which is at least one selected from a resin based on resin, a urethane based resin, a styrene based resin, or a copolymer resin thereof Attached base material.

The present invention includes a coating solution for forming a superhydrophilic film having the following constitution.
[13] A coating solution for forming a superhydrophilic film, characterized in that inorganic oxide particles having hydrophilic particle surfaces and resin emulsion particles are mixed and monodispersed in a polar solvent.
[14] The super-size according to [13], wherein the average particle size (De) of the resin emulsion particles is equal to or smaller than the average particle size (D _P ) of the inorganic oxide particles (De ≦ D _P ). Coating liquid for forming a hydrophilic film.
[15] The quantity ratio (G / [G + M]) of the amount (G) of inorganic oxide particles and the amount (M) of resin emulsion particles is in the range of 0.5 to 0.98. The coating solution for forming a superhydrophilic film according to [13] or [14].
[16] The dispersion is composed of two liquids, a dispersion in which inorganic oxide particles having hydrophilic particle surfaces are dispersed in a polar solvent, and a suspension in which resin emulsion particles are suspended in a polar solvent. The superhydrophilic film-forming coating liquid according to any one of [13] to [15], wherein the inorganic oxide particles and the resin emulsion particles are mixed in a polar solvent and monodispersed by mixing the liquids.

This invention includes the manufacturing method of the base material with a super hydrophilic film which consists of the following structures.
[17] A coating solution for forming a film, in which inorganic oxide particles having hydrophilic particle surfaces and resin emulsion particles are dispersed and suspended in a polar solvent, is applied to a base material, and the gaps between the inorganic oxide particles are formed. A resin layer is formed between the inorganic oxide particles and the gap between the inorganic oxide particles and the base material by forming a particle layer with the resin emulsion particles interposed between them and heating and drying to disintegrate the resin emulsion particles. A superhydrophilic film-coated base, wherein a superhydrophilic film having a concavo-convex structure in which an upper portion of the inorganic oxide particles is exposed from the adhesive layer is formed on a substrate A method of manufacturing the material.
[18] A dispersion of inorganic oxide particles having a hydrophilic particle surface and a suspension of resin emulsion particles are mixed, and the inorganic oxide particles and the resin emulsion particles are mixed in a polar solvent and monodispersed. The method for producing a substrate with a superhydrophilic coating film according to the above [17], wherein a coating solution for forming a coating film is prepared, and the coating solution is applied to the substrate.
[19] The average particle diameter (De) of the resin emulsion particles contained in the coating liquid for forming a film is equal to or smaller than the average particle diameter (D _P ) of the inorganic oxide particles (De ≦ D _P ). [17] The method for producing a substrate with a superhydrophilic film according to [18].
[20] The ratio (G / [G + M]) of the amount of inorganic oxide particles (G) and the amount of resin emulsion particles (M) contained in the coating liquid for forming a film is in the range of 0.5 to 0.98. The method for producing a substrate with a superhydrophilic film as described in any one of [17] to [19], wherein
[21] As emulsion resins, ester resins, polycarbonate resins, amide resins, imide resins, polyphenylene oxide resins, acrylic resins, vinyl chloride resins, vinyl acetate resins, silicone resins, urethane resins Or a resin emulsion particle suspension obtained by suspending a resin emulsion particle composed of a styrene resin or a copolymer resin thereof in a polar solvent, and an inorganic oxide particle dispersion obtained by dispersing inorganic oxide particles in a polar solvent. The above-mentioned [17] to [20] are the methods for producing a substrate with a superhydrophilic film according to any one of the above [20], wherein a coating solution for forming a film is prepared by mixing.
[22] The method according to any one of [17] to [21], wherein the coating liquid for coating formation is applied to a substrate and then dried by heating to 60 to 200 ° C. to disintegrate the resin emulsion particles. A method for producing a substrate with a superhydrophilic coating.

The substrate with a superhydrophilic film of the present invention comprises a particle layer containing inorganic oxide particles, a gap between the inorganic oxide particles, and an adhesive layer interposed in the gap between the inorganic oxide particles and the substrate. The upper part of the surface of the hydrophilic inorganic oxide particle is exposed from the adhesive layer. Water droplets are attracted to the exposed inorganic oxide particle surface, and a large uneven structure with a height difference (average height of convex portions) is formed on the coating surface due to the exposure of the inorganic oxide particles. The water droplets attracted to the surface are easily broken and have excellent hydrophilicity. Specifically, for example, the average distance (pitch width) between the convex portions the average height of the projections _{(T F)} is a 10 to 300 nm _{(W F)} have an uneven structure 1~1000nm the film surface Can have superhydrophilicity with a contact angle with water of 10 ° or less, preferably 5 ° or less.

  Moreover, since the adhesive layer is interposed in the gap between the inorganic oxide particles and in the gap between the inorganic oxide particles and the substrate, the substrate with a superhydrophilic film of the present invention has a mutual adhesion between the inorganic oxide particles and the inorganic oxide particles. Since the adhesion between the inorganic oxide particles and the substrate is good and the bonding strength between them is high, the hydrophilicity can be maintained for a long period of time, and the wear resistance is excellent.

  Since the superhydrophilic film of the present invention is transparent, a film formed on a transparent substrate such as glass or plastic is suitably used as a transparent material for a display part of a window of a building, an automobile, an observation apparatus, or a meter. Can be used.

  Further, the substrate with a superhydrophilic film of the present invention can be suitably used for a separation membrane for water treatment. In general, hydrophilic or hydrophobic separation membranes having pores corresponding to applications such as filtration membranes and osmosis membranes are used for water treatment. What formed the super hydrophilic film of this invention on the nonwoven fabric base-material surface, such as polysulfone which has the pore for water treatment, a polyethylene terephthalate, and polyester, is suitable as a base material for water treatment.

  Furthermore, the substrate with a superhydrophilic coating of the present invention is formed by forming a superhydrophilic coating on fibers such as nylon, polyester, and cotton, exterior building materials, roof tiles, etc., thereby preventing dirt from running off with running water. It can also be suitably used as a dirty material. In addition, nylon, polyester, exterior building materials, etc. may require anti-algae and antibacterial properties. In such cases, composite oxide fine particles in which a metal such as Ag, Cu, Zn is supported on inorganic oxide particles are used. Thus, it can have a plurality of functions such as anti-algae and antibacterial properties as well as hydrophilicity.

  The coating liquid for forming a film of the present invention is used in a monodispersed state in which inorganic oxide particles and resin emulsion particles are mixed, so that the particles are arranged in a monodispersed state without agglomeration during film formation, and bonded. A superhydrophilic film in which inorganic oxide particles are exposed from the layer can be easily formed on the substrate. Moreover, since the resin emulsion particles that form the adhesive layer are included together with the inorganic oxide particles in the coating liquid, it is not necessary to separately apply the adhesive layer, and the work process can be simplified.

  The method for producing a substrate with a hydrophilic coating of the present invention uses a coating-forming coating solution in which a dispersion of inorganic oxide particles having a hydrophilic particle surface and a suspension of resin emulsion particles are used. Since it is applied together with the inorganic oxide particle dispersion in the state of resin emulsion particles, there are few application operations and a hydrophilic film can be easily formed.

  In the method for producing a substrate with a hydrophilic coating according to the present invention, resin emulsion particles are interposed in a gap between inorganic oxide particles and in the gap between the inorganic oxide particles and the substrate, and the resin emulsion particles are collapsed. Since the adhesive layer is formed by allowing the resin to enter these gaps, the fine irregularities of the inorganic oxide fine particles are not filled with the matrix component, and the inorganic oxide particles and the inorganic oxide particles and the substrate are firmly bonded to each other. Therefore, it is possible to form a hydrophilic film having a high adhesion strength. Furthermore, since the inorganic oxide particles are arranged in a single layer, a base material that is highly transparent and does not impair the texture can be obtained.

In the method for producing a substrate with a hydrophilic coating of the present invention, the resin emulsion particles are interposed in the gaps between the inorganic oxide particles, and the inorganic oxide particles are not covered with the resin emulsion particles. A concavo-convex structure with a large difference in height exposed from the adhesive layer can be formed. For example, equal to the average particle diameter of the inorganic oxide particles (D _P) less (De ≦ D _P) by using the suspension of the resin emulsion particles having an average particle diameter (De), a large inorganic mean particle size upon drying The tension of the solvent present in the meniscus between the oxide particles and the substrate can cause the resin emulsion particles to be drawn into the meniscus and ensure that the inorganic oxide particles are not covered by the resin emulsion particles, for example A film in which 1/3 to 2/3 of the average particle radius of the inorganic oxide particles is exposed can be formed.

The schematic cross section of the base material with a super-hydrophilic film of this invention. Explanatory drawing which shows the contact angle with the water of the base material with a superhydrophilic film of this invention. The schematic cross section of a sunflower-like inorganic oxide particle. The schematic cross section of the base material with a super hydrophilic film using a sunflower-like particle | grain. Explanatory drawing which shows the manufacturing process of the base material with a super hydrophilic film of this invention.

[Substrate with super hydrophilic coating]
The substrate with a superhydrophilic coating of the present invention is a hydrophilic substrate having a superhydrophilic coating on the surface of the substrate, wherein the coating includes a particle layer containing inorganic oxide particles and the inorganic oxide particles mutually. And an unevenness in which the surface of the inorganic oxide particle is hydrophilic and the upper part of the inorganic oxide particle is exposed from the adhesive layer. A substrate with a superhydrophilic film, characterized by having a structure on the surface of the film.

  An example of the substrate with a superhydrophilic film of the present invention is shown in FIG. As shown in the figure, the superhydrophilic film-coated substrate 10 has a substrate 1 and a superhydrophilic film 2 formed on the surface of the substrate 1. The coating 2 is formed by a particle layer 3 and an adhesive layer 4. The particle layer 3 is a layer in which a large number of inorganic oxide particles 5 are dispersed and arranged on the substrate surface, and is basically formed as a single layer. The adhesive layer 4 is a layer made of an adhesive component, and is interposed in the gap between the inorganic oxide particles 5 and the gap between the inorganic oxide particles 5 and the substrate 1. The adhesive layer 4 is formed by the disintegration of the resin emulsion particles interposed in the gaps between the inorganic oxide particles 5 and the gaps between the inorganic oxide particles 5 and the substrate 1. The upper part of the inorganic oxide particles 5 is exposed from the surface of the adhesive layer 4, and the upper part of the inorganic oxide particles 5 is exposed to form a concavo-convex structure with a large difference in height.

The average particle diameter (D _P ) of the inorganic oxide particles 5 is preferably in the range of 20 to 600 nm. When the average particle diameter (D _P ) of the inorganic oxide particles 5 is less than 20 nm, when the film thickness (U _F ) of the adhesive layer 4 is close to the upper limit value of the following film thickness range, The portion is taken into the adhesive layer 4, and the height of the convex portion exposed from the adhesive layer 4 is reduced, so that a concavo-convex structure having a sufficient height difference cannot be obtained. On the other hand, if the average particle diameter (D _P ) of the inorganic oxide particles exceeds 600 nm, the average height of the convex portions of the concavo-convex structure may be outside the desired range, and the target concavo-convex structure cannot be obtained. The average particle diameter (D _P ) of the inorganic oxide particles is the layer thickness of the particle layer 3.

The layer thickness (U _F ) of the adhesive layer 4 is preferably in the range of 6 to 400 nm. When the film thickness (U _F ) of the adhesive layer 4 is less than 6 nm, the adhesive layer of the inorganic oxide particles 5 when the average particle diameter (D _P ) of the inorganic oxide particles 5 is close to the upper limit of the particle size range. The depth embedded in 4 decreases, and sufficient adhesive strength cannot be obtained. When the film thickness (U _F ) of the adhesive layer 4 exceeds 400 nm, when the average particle diameter (D _P ) of the inorganic oxide particles 5 is close to the lower limit of the particle size range, the inorganic oxide particles 5 are bonded. The height exposed from the layer 4 becomes small, and a concavo-convex structure with a large height difference cannot be obtained.

The ratio (U _F / D _P ) of the thickness (U _F ) of the adhesive layer to the average particle diameter (D _P ) of the inorganic oxide particles 5 is preferably 1/3 to 2/3. It is preferable that 1/3 to 2/3 of the average particle diameter (D _P ) of the particles 5 is exposed from the adhesive layer 4. In this way, 1/3 to 2/3 of the average particle diameter D _P ) of the inorganic oxide particles 5 is exposed from the adhesive layer 4, so that a concavo-convex structure with a large difference in height is formed on the surface of the coating 2. As a result, the surface of the coating 2 has high hydrophilicity.

Specifically, for example, as shown in FIG. 1, the substrate 10 with a superhydrophilic film of the present invention has a concavo-convex structure on the surface of the film 2 having an average height (T _F ) of a convex part of 10 to 300 nm. The range is preferable, and the average distance (pitch width) (W _F ) between the convex portions is preferably in the range of 1 to 1000 nm. If the average height (T _F ) of the convex portion is less than 10 nm, the height difference of the concave-convex structure becomes small and it becomes difficult to increase the hydrophilicity of the coating film. On the other hand, the hydrophilicity does not change much even if the average height of the convex part ( _TF ) is larger than 300 nm. Further, if the pitch width (W _F ) between the protrusions is less than 1 nm, the recesses become narrow, and if the pitch width (W _F ) between the protrusions exceeds 1000 nm, the recesses are too wide. The effect of the uneven structure becomes insufficient, and it becomes difficult to increase the hydrophilicity of the coating.

  The thickness of the hydrophilic coating is preferably in the range of 20 nm to 700 nm, and more preferably in the range of 40 to 600 nm. When the film thickness is less than 20 nm, the durability is lowered and it is difficult to form a sufficient uneven structure on the surface. On the other hand, even if the film thickness is larger than 700 nm, the hydrophilic effect does not change much.

〔Base material〕
The material of the substrate 1 is not limited. For example, glass, polycarbonate, acrylic resin, PET, TAC, polyester resin, nylon resin or other plastic sheet, plastic film, plastic panel, fiber, nonwoven fabric, mortar material, slate material, concrete, or the like can be used. . The adhesive layer 4 is an ester resin, polycarbonate resin, amide resin, imide resin, polyphenylene oxide resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, silicone resin, urethane resin, or styrene resin. It can be formed by at least one selected from a resin, a styrene resin, and a copolymer resin thereof.

[Inorganic oxide particles]
The inorganic oxide particles 5 include, for example, SiO ₂ , Al ₂ O ₃ , Sb ₂ O ₅ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , CeO ₂ , AgO, CuO, Cu ₂ O, and composite oxides thereof. Alternatively, at least one selected from a mixture can be used. The surface of these inorganic oxide particles 5 is generally hydrophilic, and the upper portion of the inorganic oxide particles 5 is exposed from the adhesive layer 4, so that the hydrophilic range is larger than that of a conventional coating film without an uneven structure. wide. For this reason, as shown in FIG. 2, the water droplet 6 in contact with the surface of the coating 2 is attracted to the surface by affinity with the surface of the inorganic oxide particles, and the surface has a concavo-convex structure with a large difference in height. The water droplet 6 is liable to collapse, and the surface of the coating 2 becomes highly hydrophilic. Specifically, it can have super hydrophilicity with a contact angle θ between the water droplet 6 and the surface of the coating 2 of 5 ° or less.

As the inorganic oxide particles 5, those having improved hydrophilicity by surface treatment can be used. As such a hydrophilic surface treating agent, for example, a hydrolyzable organosilicon compound represented by the formula of SiX ₄ (wherein X: an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, halogen, hydrogen) is used. it can. Examples of the hydrolyzable organosilicon compound include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

The shape of the inorganic oxide particles 5 may be any shape as long as the uneven structure can be formed, and is not limited. For example, any shape of spherical particles, confetti particles, and sunflower particles can be used. These spherical particles, confetti particles, sunflower particles and the like may have a porous structure. Spherical particles can be easily in a state in which 1/3 to 2/3 of the average particle diameter (D _P ) is exposed from the adhesive layer 4, and a concavo-convex structure with a large difference in height can be formed on the coating surface. These particles are preferably single particles, but may have a structure in which 2 to 3 particles are connected. Note that when there are four or more connected structures, voids exist between the substrate and the particles, and the film as shown in FIG. 1 may not be obtained.
Further, since the sunflower-like particles have moderate irregularities on the particle surface and further have fine irregularities on the irregular surface, a hydrophilic coating having excellent hydrophilicity can be obtained. The average particle diameter of these particles is determined based on the length of the major axis.

Porous spherical inorganic oxide particles Porous spherical inorganic oxide particles are spherical fine particles having a large number of pores on the surface of the inorganic oxide particles. The average particle diameter (D _A ) of the porous spherical inorganic oxide particles is preferably in the range of 10 to 600 nm, more preferably 10 to 1300 nm. When the average particle diameter (D _A ) of the porous spherical inorganic oxide particles is less than 10 nm, it is difficult to obtain because the specific surface area becomes large. If the average particle diameter (D _A ) exceeds 600 nm, the strength, hardness, and adhesion to the substrate may be insufficient.

Since the porous spherical inorganic oxide particles have micropores (PD), the specific surface area (SA) is large. The specific surface area (SA) is a specific surface area measured by the BET method, and the micropores (PD) can be measured by the same method. The specific surface area (SA) of the porous spherical inorganic oxide fine particles varies depending on the particle diameter, but is preferably 100-1500 m ² . When the specific surface area (SA) is less than 100 m ² , the fine uneven structure on the particle surface is small, and sufficient hydrophilicity may not be obtained when formed into a film. When the specific surface area (SA) exceeds 1500 m ² , sufficient hydrophilicity can be obtained. However, since the specific surface area is large, the interaction between particles increases, and a stable paint may not be obtained.

  The pore diameter (PD) of the porous spherical inorganic oxide fine particles varies depending on the particle diameter, but is preferably 0.1 to 5 nm. When the pore diameter (PD) is smaller than 0.1 nm, there are few fine uneven structures when formed into a film, and sufficient hydrophilicity may not be obtained when formed into a film. When the pore diameter (PD) exceeds 5 nm, sufficient hydrophilicity can be obtained, but the strength of the particles is weak, and the strength at the time of obtaining a film may be weak.

Gold-peeled inorganic oxide particles Gold-peeled inorganic oxide particles are spherical fine particles having a number of ridge-like projections on the surface of the particles, and the structure thereof is generally similar to that of gold-peeled sugar. The average particle diameter (D _A ) of the confetti-like inorganic oxide particles is preferably in the range of 10 to 150 nm, more preferably 10 to 130 nm. The confetti-like inorganic oxide average particle diameter (D _A) is less than 10nm particles, it is difficult to obtain as particles having a wart-like projections, it is difficult to form desired fine irregularities. On the other hand, if the average particle size (D _A ) of the confetti inorganic oxide particles exceeds 150 nm, the strength, hardness, and adhesion to the substrate of the hydrophilic coating may be insufficient.

  The average height (H) of the ridge-like projections of the confetti-like inorganic oxide particles is preferably in the range of 0.3 to 45 nm, and more preferably in the range of 0.5 to 40 nm. If the average height (H) of the hook-shaped projections is less than 0.3 nm, the hydrophilicity of the hydrophilic film may be insufficient. When the average height (H) of the hook-like protrusions exceeds 45 nm, the hook-like protrusions are too large, and the number of hook-like protrusions on the particle surface is reduced, so that the number of fine irregularities is reduced.

The ratio (H) / (D _A ) between the average height (H) of the ridge-like protrusions of the confetti-like inorganic oxide particles and the average particle diameter (D _A ) of the confetti-like inorganic oxide particles is 0.03 to 0.03. The range of 30 is preferable, and the range of 0.05 to 0.27 is more preferable. When the ratio (H) / (D _A ) is less than 0.03, the hydrophilicity of the hydrophilic film may be insufficient. On the other hand, when the ratio (H) / (D _A ) exceeds 0.30, the ridge-like protrusions are too large, and the number of ridge-like protrusions on the particle surface decreases, so the number of fine irregularities decreases.

The surface roughness formed by the ridge-like projections of the confetti-like inorganic oxide particles can be expressed by the following formula (1). In addition, (SA ₁ ) is a specific surface area measured by the BET method, (SA ₂ ) is a specific surface area calculated by an equivalent sphere conversion formula represented by the following formula (2), and d is a confetti-like inorganic substance It is the density of oxide particles, and 6000 is a conversion factor.
Surface roughness of confetti sugar-like inorganic oxide particles = (SA ₁ ) / (SA ₂ ) (1)
(SA ₂ ) = 6000 / (D _A ) × d (2)

Here, since the specific surface area indicates the surface area per unit mass, the value of the surface roughness (SA ₁ ) / (SA ₂ ) is such that the more spherical the particle surface is, the more (SA) ₁ ) / (SA ₂ ) increases, while the smaller the number of wrinkles on the particle surface and the smoother, the smaller the value of (SA ₁ ) / (SA ₂ ), which is close to 1. Become.

The surface roughness (SA ₁ ) / (SA ₂ ) of the gold flat sugar-like inorganic oxide particles used in the present invention is preferably in the range of 1.7 to 5.0. When the surface roughness is less than 1.7, the ratio of the ridge-like protrusions is small, or the ridge-like protrusions themselves are extremely smaller than the particle size of the confetti-like inorganic oxide particles, and become close to spherical fine particles. On the other hand, when the surface roughness value exceeds 5.0, preparation is difficult. The range of the surface roughness is more preferably in the range of 1.8 to 4.5.

The average particle diameter (D _A ) and the average height (H) of the ridge-like protrusions of the confetti-like inorganic oxide particles can be measured by image analysis of a scanning electron micrograph (SEM). Specifically, for example, for an arbitrary 50 particles in a projection image taken with a scanning electron microscope, the maximum diameter may be measured and the average value may be set as the average particle diameter (D _A ). Further, the distance from the apex of an arbitrary hook-shaped protrusion to the contact point between the hook-shaped protrusion and the spherical particle portion is measured at three locations, and the average value may be set as the average height (H) of the hook-shaped protrusion.

Sunflower-like inorganic oxide particles sunflower like inorganic oxide particles (hereinafter, also referred to as sunflower-like particles.) The cross-section of FIG. 3. As shown in the figure, the sunflower-like particles 20 are formed of inorganic oxide substrate particles 21 and inorganic oxide fine particles 22 covering the surface of the substrate particles. The illustrated base particle 21 is schematically spherical, but may be irregular, plate-like, or polyhedral. The fine particles 22 are spherical particles, and the entire cross section of the particles is a sunflower-like particle. Since the surface of the base particle 21 has fine irregularities due to the fine particles 22, the sunflower-like particles 20 have high hydrophilicity, strong adhesion, fouling and deterioration due to the hydrophilic coating are effectively suppressed, and antifouling is achieved. And can maintain high hydrophilicity over a long period of time.

The convex average height (T _FF ) of the fine irregularities is preferably in the range of 0.5 to 10 nm, and the average distance (pitch width) (W _FF ) between the convexes of the fine irregularities is preferably in the range of 1 to 30 nm. . If the average height of the protrusion (T _FF ) is smaller than the above range, it is difficult to form sufficient fine unevenness, and if it exceeds the above range, the fine recess is too deep. Since air tends to remain and it is difficult to obtain a hydrophilic film, it is not preferable. Further, if the average distance (pitch width) (W _FF ) between the convex portions of the fine irregularities is smaller than the above range, it is difficult to obtain sufficient fine irregularities, and those exceeding the above range have a large particle diameter of the fine particles 22. The number of fine particles 22 covering the surface of the base particle 21 is limited, and it is difficult to form sufficient fine irregularities on the surface of the base particle.

The average particle diameter (D _C1 ) of the base particles 21 of sunflower-like particles is preferably in the range of 40 to 600 nm, and more preferably in the range of 50 to 500 nm. When this average particle diameter (D _C1 ) is small, the height of the convex portions and the distance between the convex portions (pitch width) may be too small when applied on the substrate, and it is difficult to obtain high hydrophilicity. On the other hand, even if the average particle diameter (D _C1 ) is too large, the height of the protrusions and the distance between the protrusions (pitch width) become too large, and it is difficult to obtain a high hydrophilic film.

The average particle diameter (D _C2) having an average particle diameter (D _C1) and fine particles 22 of the base particles 11 is the average particle diameter determined by the equivalent spherical conversion formula represented by the following formula (3). Incidentally, D is the average particle diameter (nm), SA _M is measured specific surface area by the BET method ^{(m 2} / g), d the density of the particle (g / cm ^3), 6000 is a conversion factor. The average particle diameter can be measured using a dynamic light scattering method (Nikkiso Co., Ltd .: Microtrac UPA). The actual measured value of the specific surface area is measured by the BET method.
D = 6000 / SA _M xd (3)

The average particle diameter (D _C2 ) of the fine particles 22 is preferably in the range of 4 to 60 nm, and more preferably in the range of 5 to 40 nm. When the average particle diameter (D _C2 ) is small, it is difficult to obtain sunflower-like inorganic oxide particles that are stably monodispersed. Even if the average particle diameter (D _C2 ) is too large, fine irregularities are increased and the specific surface area of the sunflower-like inorganic oxide particles is also decreased, so that it is difficult to obtain sufficient hydrophilicity.

The average ratio of particle diameter _{(D C2)} having an average particle diameter _{(D C1)} and fine particles 22 of the base particles _{21 (D C2) / (D} C1) is preferably in the range of 0.007 to 0.5, 0. The range of 008 to 0.4 is more preferable. When the ratio (D _C2 ) / (D _C1 ) is smaller than the above range, fine irregularities are reduced, and it is difficult to obtain sufficient hydrophilicity. Fine irregularities with the ratio (D _C2 ) / (D _C1 ) exceeding the above range become large, and it is difficult to obtain sufficient hydrophilicity.

  The coverage of the base particles 21 with the fine particles 22 is expressed by the following formula (4). The coverage is preferably in the range of 30 to 100%, and more preferably in the range of 50 to 100%. If the coverage is small, sufficient fine irregularities cannot be formed. The average particle diameter of the sunflower-like particles with the fine particles 22 coated on the surface of the substrate particles 21 is generally in the range of 48 to 720 nm, although it varies depending on the coverage.

Covering rate (%) = {[actual specific surface area of sunflower-like inorganic oxide particles (S _C1 ) −measured specific surface area of inorganic oxide particles for substrate (S _M )] / [100% covered) Calculated specific surface area of sunflower-like inorganic oxide particles (S _C ) —Measured specific surface area of inorganic oxide particles for substrate (S _M )]} × 100 (4)

(S _C) = sunflower-shaped inorganic oxide particle number of the particle surface area × unit weight (1 g) per 1 per.
Surface area per sunflower-like inorganic oxide particle = 4π · [(D _C1 ) / 2 + (D _C2 ) / 2] ²
Number of substrate particles per unit weight (1 g) = 1 / [4/3 · π [(D _C1 ) / 2] ³ · d]
d represents the particle density (g / ml) of the substrate particles. The particle density of silica is 2.2 g / ml.

The components of the base particles 21 and the fine particles 22 may be the same or different. SiO ₂ , Al ₂ O ₃ , Sb ₂ O ₅ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , CeO ₂ , AgO, It is preferably at least one selected from CuO, Cu ₂ O, and complex oxides or mixtures thereof. As the particles of these components, spherical particles having a particle diameter in the above range can be easily obtained, and since they are chemically stable, they can be preferably used. Among these, particles made of SiO ₂ are preferable. As for the SiO ₂ particles, spherical particles having a uniform particle diameter can be obtained regardless of the size of the particle diameter, and are chemically stable.

  The sunflower-like particles are prepared by mixing an aqueous dispersion of base particles having a positive or negative surface potential and an aqueous dispersion of fine particles having the opposite surface electricity to adjust the pH to a weak acidity, Is passed through an ion exchange resin to remove anions, the pH is adjusted to a neutral range, and drying is performed.

  FIG. 4 shows a cross-sectional view of a substrate with a superhydrophilic film using sunflower particles 20 as the inorganic oxide particles 5. A large uneven structure is formed on the surface of the coating 2 by the base particles 21, and fine unevenness is formed on the surface of the base particles 21 by the fine particles 22. Since these surfaces are hydrophilic, water droplets coming into contact with the surface of the coating 2 are attracted to these hydrophilic surfaces. Furthermore, since the surface on which the water droplets are attracted has a double concavo-convex structure consisting of a large concavo-convex structure formed by the base particles 21 and a fine concavo-convex structure formed by the fine particles 22, the water droplets attracted to the concavo-convex structure are easily broken. And higher hydrophilicity is exhibited.

  The hydrophilicity of the inorganic oxide particle surface increases as the number of —OH groups on the particle surface increases, and in addition to the number of —OH groups, the surface of the inorganic oxide particle has nano-sized fine irregularities. The hydrophilicity is further increased.

  In addition, after forming a particle layer of inorganic oxide particles, the particle layer is coated with a partial hydrolyzate of metal alkoxide, a monomer of an organic resin, or a molecular matrix component of a polymer to adhere the particle and the substrate. Alternatively, when the particle layer is formed using a coating liquid containing a matrix component in which emulsion resin particles larger than inorganic oxide particles and inorganic oxide particles are mixed, a super hydrophilic film is formed when the matrix component fills fine irregularities. Cannot be obtained. In addition, when such a matrix component is used, it is known that inorganic oxide particles are clustered to form a film, but the film adhesion is insufficient, or a film is formed on the fiber. As a result, the texture of the fiber may be impaired, or a film with low transparency may be obtained when it is desired to obtain a transparent film.

  On the other hand, since the superhydrophilic film of the present invention does not have a top coat on the upper side of the particle layer, the uneven structure due to the exposure of the particles and the fine unevenness due to the fine particles of the sunflower-like particles are not embedded by the top coat, and the highly hydrophilic film Demonstrate sex. Moreover, it is excellent in the adhesiveness of the coating, and even if a coating is formed on the fiber, the texture of the fiber is not impaired, and a highly transparent coating can be obtained.

[Super hydrophilic coating liquid]
The coating liquid for forming a film for producing a substrate with a superhydrophilic film according to the present invention has inorganic particles having hydrophilic particle surfaces and resin emulsion particles monodispersed in a polar solvent. It is good to use the coating liquid characterized by these. In the coating solution, the average particle diameter (De) of the resin emulsion particles is preferably equal to or smaller than the average particle diameter (D _P ) of the inorganic oxide particles (De ≦ D _P ). By making the average particle diameter (De) of the resin emulsion particles equal to or smaller than the average particle diameter (D _P ) of the inorganic oxide particles (De ≦ D _P ), the inorganic oxide particles are hardly covered with the resin emulsion particles. Can do. If the average particle size (De) of the resin emulsion particles is larger than the average particle size (D _P ) of the inorganic oxide particles, the inorganic oxide particles may be covered with the collapsed resin when the resin emulsion particles are collapsed. is there.

  In the coating solution, the ratio (G / [G + M]) of the amount of inorganic oxide particles (G) to the amount of resin emulsion particles (M) is 0.5 or more (inorganic oxide particle amount G is 50% by weight). The above range is preferable, and the range of 0.5 to 0.98 is more preferable. If the amount ratio (G / [G + M]) is smaller than the above range, the number of inorganic oxide particles in the coating is decreased, and there is a concern that the hydrophilicity and durability of the coating are insufficient. On the other hand, if the amount ratio (G / [G + M]) is larger than the above range, the amount of resin is relatively small, and there is a concern that the adhesive strength is lowered.

  The coating liquid may be composed of two liquids: a dispersion liquid in which inorganic oxide particles having hydrophilic particle surfaces are dispersed in a polar solvent and a suspension liquid in which resin emulsion particles are suspended in a polar solvent. This two-part coating solution is prepared by mixing an inorganic oxide particle dispersion and a resin emulsion particle suspension to form a coating solution in which inorganic oxide particles and resin emulsion particles are mixed and dispersed in a polar solvent. Use. Storage stability can be improved by using two liquids. The coating solution (b) has good workability because it is not necessary to mix the two solutions at the time of use.

Preparation of inorganic oxide particle dispersion The inorganic oxide particle dispersion is a liquid in which inorganic oxide particles having a hydrophilic particle surface are dispersed in a polar solvent. Inorganic oxide particles are added to a polar solvent and stirred with a mixer or the like to prepare an inorganic oxide particle dispersion. The average particle diameter (D _P ) of the inorganic oxide particles is preferably in the range of 20 to 600 nm. The solid content concentration of the inorganic oxide fine particle dispersion is preferably 0.1 to 20% by weight, and more preferably 0.2 to 15% by weight.

For example, the following solvents (A) to (G) can be used as the polar solvent of the inorganic oxide particle dispersion. These may be used singly or in combination of two or more.
(A) Alcohols such as methanol, ethanol, propanol, 2-propanol (IPA), butanol, diacetone alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol.
(B) Esters such as methyl acetate, ethyl acetate, isopropyl acetate, isopropyl acetate, isobutyl acetate, butyl acetate, isopentyl acetate, pentyl acetate, 3-methoxybutyl acetate, 2-ethylbutyl acetate, cyclohexyl acetate, and ethylene glycol monoacetate.
(C) Glycols such as ethylene glycol and hexylene glycol.
(D) Diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, pull Ethers such as pyrene glycol monopropyl ether.
(E) Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl methyl ketone, cyclohexanone, methyl cyclohexanone, dipropyl ketone, methyl pentyl ketone, and diisobutyl ketone.
(F) Toluene, N-methylpyrrolidone, etc.
(G) Water

Preparation of Resin Emulsion Particle Suspension Resin emulsion particle suspension is a suspension in which resin emulsion particles are suspended in a polar solvent. Emulsion resins include ester resins, polycarbonate resins, amide resins, imide resins, polyphenylene oxide resins, acrylic resins, vinyl chloride resins, vinyl acetate resins, silicone resins, urethane resins, or Styrenic resins or copolymer resins thereof are preferred. Since the resin emulsion particles are collapsed in the film forming step to form an adhesive layer, these resins become components of the adhesive layer.

  If the resin is added to a polar solvent and stirred with a mixer or the like, resin emulsion particles are formed in the polar solvent, and a resin emulsion particle suspension can be obtained. A polar solvent similar to the inorganic oxide particle dispersion can be used. The particle diameter of the resin emulsion particles can be adjusted by adding a surfactant or a pH adjuster and stirring at high speed. The addition amount of the surfactant and the pH adjusting agent and the stirring speed may be adjusted so that the resin emulsion particles have a desired particle size depending on the kind of the resin and the polar solvent, the amount of the resin in the dispersion, and the like. A commercially available product can be used as the resin emulsion particle suspension.

Preparation of coating solution for film formation For coating film formation, inorganic oxide particle dispersion and resin emulsion particle suspension are mixed and stirred to mix inorganic oxide particles and resin emulsion particles in a polar solvent. A coating solution is prepared. It is advisable to add a silicic acid solution to the inorganic oxide particle dispersion and heat aging to mix the resin emulsion particle suspension. When the silicic acid solution is added, the fine particles of the sunflower particles and the base particles adhere well, and the fine particles do not fall off. Instead of preparing the resin emulsion particle suspension, the resin may be directly added to the inorganic oxide particle dispersion and stirred to form the resin emulsion particles to prepare a coating liquid for forming a film.

  In the coating solution, a crosslinking material or a crosslinking inhibitor may be added to control the temperature at which the emulsion particles are disintegrated and fixed. Furthermore, a leveling agent and a dispersing agent can be added to make the coating film cleaner. Moreover, you may put a photoinitiator and a thermosetting accelerator as needed.

  In the coating liquid for forming a film, the inorganic oxide particle concentration is preferably in the range of 0.1 to 10% by weight, and more preferably in the range of 0.5 to 8% by weight. When the concentration is lower than the above range, the thickness of the inorganic oxide particle layer is thin, and desired irregularities may not be formed, and coating unevenness without the inorganic oxide particle layer is likely to occur. Strength, hardness, and scratch resistance may not be obtained. On the other hand, when the concentration is higher than the above range, although depending on the coating method, there are cases where the coating property is lowered and desired irregularities cannot be formed. In addition, the inorganic oxide particle layer may become too thick, resulting in a decrease in transparency and an increase in haze.

  The concentration of the resin emulsion in the coating solution is preferably in the range of 0.1 to 10% by weight, more preferably in the range of 0.5 to 8% by weight. If the resin emulsion concentration is lower than the above range, an adhesive layer having a sufficient film thickness cannot be formed, and the adhesive strength may be lowered. On the other hand, when the resin emulsion concentration is higher than the above range, the inorganic oxide particle concentration is relatively low, the thickness of the inorganic oxide particle layer is thin, and desired unevenness may not be formed.

The average particle size (De) of the resin emulsion particles contained in the coating liquid for forming a film is preferably equal to or smaller than the average particle size (D _P ) of the inorganic oxide particles (De ≦ D _P ). By making the average particle diameter (De) of the resin emulsion particles equal to or smaller than the average particle diameter (D _P ) of the inorganic oxide particles (De ≦ D _P ), the inorganic oxide particles are hardly covered with the resin emulsion particles. For example, a film in which 1/3 to 2/3 of the average particle radius of the inorganic oxide particles is exposed from the adhesive layer can be formed. If the average particle size (De) of the resin emulsion particles is larger than the average particle size (D _P ) of the inorganic oxide particles, the inorganic oxide particles may be covered with the collapsed resin when the resin emulsion particles are collapsed. This is not preferable.

  The amount ratio (G / [G + M]) of the amount (G) of inorganic oxide particles contained in the coating liquid for coating formation and the amount (M) of resin emulsion particles is 0.5 or more (the amount of inorganic oxide particles G is A range of 50% by weight or more is preferable, and a range of 0.5 to 0.98 is more preferable, and if the amount ratio (G / [G + M]) is smaller than the above range, the number of inorganic oxide particles in the coating is reduced. On the other hand, when the ratio (G / [G + M]) is larger than the above range, the amount of resin is relatively small, and the adhesive strength may be lowered. There is.

[Method for producing substrate with super hydrophilic coating]
The substrate with a superhydrophilic film of the present invention uses the coating liquid for forming a film, and applies the coating liquid to the substrate to form a particle layer in which the resin emulsion particles are interposed between the inorganic oxide particles. After forming, applying and drying by heating, the resin emulsion particles are disintegrated to allow the resin to enter the gap between the inorganic oxide particles and the gap between the inorganic oxide particles and the base material to form an adhesive layer, It is manufactured by forming a superhydrophilic film having a concavo-convex structure in which the upper part of the inorganic oxide particles is exposed from the adhesive layer on a substrate.

  FIG. 5 shows an outline of a method for producing a substrate with a superhydrophilic film. The manufacturing process shown in the figure includes the following (I) inorganic oxide particle dispersion preparation step, (II) resin emulsion particle suspension adjustment step, and (III) the dispersion and the suspension are mixed to form a coating solution. A step of preparing, (IV) a coating step, and (V) an adhesive layer forming step. In addition, it may replace with (I) process-(III) process, and may form a film by (IV) application | coating process and (V) contact bonding layer formation process using the coating liquid for film formation prepared previously.

(I) A step of adjusting the dispersion 30 in which the inorganic oxide particles 5 are dispersed in the polar solvent 31 (inorganic oxide particle dispersion preparing step).
(II) A step of preparing a resin emulsion particle suspension 34 in which the resin emulsion particles 32 are suspended in a polar solvent 33 (resin emulsion particle suspension adjustment step).
(III) A step of preparing the coating solution 35 for coating formation by mixing the dispersion 30 and the suspension 34 (coating solution preparation step).
(IV) The process of apply | coating the coating liquid 35 to the base material 1, and forming the particle layer in which the resin emulsion particle | grains 32 intervened in the mutual gap | interval of the inorganic oxide particle 5 (application | coating process).
(V) The coating liquid is heated and dried to disintegrate the resin emulsion particles 34 so that the resin enters the gaps between the inorganic oxide particles 5 and the gaps between the inorganic oxide particles 5 and the substrate 1. Forming the adhesive layer 4 with the upper portion exposed (adhesive layer forming step).

The production steps (IV) to (V) will be described in detail.
(IV) Coating step: A coating solution is coated on a substrate to form a particle layer in which resin emulsion particles are interposed between the inorganic oxide particles. The coating method is not particularly limited, and for example, a bar coater method, a dip method, a spray method, a spinner method, a roll coating method, a gravure coating method, a slit coating method, a pressure coating method, or the like can be used. Since the coating solution contains the resin emulsion particles together with the inorganic oxide particles, the inorganic oxide particles and the resin emulsion particles can be coated on the substrate by a single coating operation. In addition, since the inorganic oxide particles and the resin emulsion particles are uniformly dispersed in the coating solution, this coating operation forms a particle layer in which the resin emulsion particles are interposed in the gaps between the inorganic oxide particles. Can do.

(V) Adhesive layer forming step: The applied liquid is dried by heating, the resin emulsion particles are collapsed, and the resin enters the gaps between the inorganic oxide particles and between the inorganic oxide particles and the substrate. The heating temperature may be a temperature at which the resin emulsion particles collapse. Although it varies depending on the type of resin, generally, when heated to 60 to 200 ° C., the resin emulsion particles collapse and the resin flows out. Thereafter, if necessary, curing may be promoted by UV irradiation or annealing.

  The base material with a hydrophilic film produced by the above steps is composed of an uneven structure having a large height difference formed by exposing the inorganic oxide particles together with the hydrophilicity of the surface of the inorganic oxide particles, and also the inorganic oxide. It has high hydrophilicity due to a synergistic effect with shape characteristics due to fine irregularities on the particle surface. Specifically, it can have super hydrophilicity with a contact angle with water of 10 ° or less, preferably 5 ° or less.

  Hereinafter, the present invention will be specifically described by way of examples. In addition, this invention is not limited by these Examples.

[Example 1]
[Standard particle size sunflower-like particles, resin standard, acrylic-styrene]
Preparation of inorganic oxide particle (sunflower-like particle) dispersion [A1] ( Preparation of substrate particles)
750 g of silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd .: Cataloid SI-80P, average particle diameter 80 nm, surface potential -60 mV, SiO ₂ concentration 20 wt%, pH 10.2), 150 g of cation exchange resin (ROHMHARS: Duolite) Were mixed and stirred for 0.5 hour. Next, after separating the cation exchange resin, 135 g of an anion exchange resin (Mitsubishi Chemical Co., Ltd .: SUNUP-C) was mixed and stirred for 0.5 hour, and then the anion exchange resin was separated to obtain SiO ₂ concentration. 750 g of 20% by weight purified silica sol was prepared.
(Preparation of substrate particle dispersion)
To 750 g of purified silica sol, 5.1 g of polyaluminum chloride (manufactured by Taki Chemical Co., Ltd .: Takibaine # 1000, Al ₂ O ₃ concentration 23.55 wt%) was added and stirred at room temperature for 0.5 hour. Subsequently, 2903 g of pure water was added and diluted to prepare 3658 g of a base particle dispersion liquid composed of silica having a SiO ₂ concentration of 4.1 wt%. The pH of the substrate particle dispersion was 3.7.
(Addition of fine particles)
Silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd .: Cataloid SN-350, average particle diameter 7 nm, surface potential -23 mV, SiO ₂ concentration as a fine particle for coating to 3658 g of the substrate particle dispersion (SiO ₂ concentration 4.1 wt%) 294 g of 16.6 wt%, pH 3.7) were mixed. This mixed dispersion had a SiO ₂ concentration of 5.0% by weight and a pH of 3.5.
(Preparation of sunflower-like particle dispersion)
135 g of an anion exchange resin (manufactured by Mitsubishi Chemical Co., Ltd .: SUNUP-C) was mixed with the mixed dispersion and stirred for 0.5 hour, and then the anion exchange resin was separated, and the SiO ₂ concentration was 10 with a rotary evaporator. A sunflower-like particle dispersion [A] composed of silica by weight was prepared. The dispersion H was 7.0.
(Measurement of average particle diameter D _P)
The average particle diameter of the sunflower-like particles was taken as an average value obtained by taking a transmission electron micrograph (TEM) and measuring 10 major diameters.
(Measurement of coverage)
The dispersion of the sunflower-like particles was heated to 120 ° C. and dried, and the specific surface area of the sunflower-like particles was measured by the BET method to determine the coverage. The coverage was determined according to the above equation (4).

Preparation of Coating Solution for Coating Form [C1] To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 2 g of resin emulsion particle suspension [B1] (CG 8370 manufactured by DIC: particle size 100 nm: concentration 50 wt%, acrylic-styrene) was added, and then ethanol was added to adjust the solid content concentration to 5 wt%. Then, the mixture was stirred for 1 hour at room temperature with a magnetic stirrer to obtain a coating solution for film formation [C1]. The pH of the coating solution was 7.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.

Manufacture of substrate [D1] with hydrophilic coating Coating solution [C1] for coating formation is applied to a glass substrate (Hamashinsha product: FL glass, thickness: 3 mm, refractive index: 1.51) by a bar coater method. And it dried for 10 minutes at 80 degreeC, and manufactured the base material [D1] with a hydrophilic film. The thickness of the dried film, the average height of protrusions (T _F ) in the uneven structure of the film, the pitch width (W _F ) between the protrusions, the thickness of the inorganic oxide particle layer (D _P ), the thickness of the adhesive layer ( The U _F ) and (U _F ) / (D _P ) ratios are shown in Table 2.

Convex part average height (T _F ) and pitch width (W _F ) are taken by transmission electron micrograph (TEM) of the cross section of the hydrophilic coating, and the height of the ten convex parts and the distance between the pitches are measured. The average value was used. The inorganic oxide particle layer thickness (D _P ) and adhesive layer thickness (U _F ) are similarly measured by taking a transmission electron micrograph (TEM) of a cross section of the hydrophilic coating and measuring the thickness of these 10 locations. The average value was used, and the film thickness ratio (U _F / D _P ) was calculated using this average value.

Furthermore, regarding the inorganic oxide particles, Table 1 shows the fine unevenness (T _FF ) and the pitch width (W _FF ) of the fine unevenness. The fine unevenness (T _FF ) was measured in the 500 nm range using AFM. Further, the surface roughness (Ra) on the single particle was measured at three points, and the average value was defined as fine irregularities. The pitch width (W _FF ) of the fine irregularities was obtained by photographing a scanning electron microscopic amount (SEM), measuring the height of 10 convex portions and the distance between pitches, and taking the average value.

  The resulting film was measured for pencil hardness, adhesion, hydrophilicity, stain removal, total light transmittance, and haze. The results are shown in Table 2. The total light transmittance and haze were measured with a haze meter (manufactured by Suga Test Instruments Co., Ltd.). The uncoated glass had a total light transmittance of 92.0% and a haze of 0.1%.

The hydrophilicity, pencil hardness, adhesion, and dirt removal properties of the coating were measured by the following methods.
(A) Hydrophilicity The hydrophilicity was measured by using a fully automatic contact angle meter (DM700 manufactured by Kyowa Interface Science Co., Ltd.) and the contact angle with 5 μL water.
(B) Pencil hardness Pencil hardness was measured with a pencil hardness tester in accordance with JIS-K-5600. The evaluation criteria are shown below.
2H or more: ◎ H to 2H: ○
B to H: Δ B or less: ×
(C) Adhesion Adhesion is achieved by making 11 parallel scratches with a knife on the surface of the substrate (1) with a hydrophilic transparent coating (1) at intervals of 1 mm in length and width, and attaching cellophane tape to this. Adhesiveness was evaluated by classifying the number of cells remaining without peeling when the film was peeled into the following three stages. The evaluation criteria are shown below.
Number of remaining cells: ◎ Number of remaining cells: 95 to 99: ○
Number of remaining cells 90 to 94: Δ Number of remaining cells 89 or less: ×
(D) Stain-off property The soil-removal property is determined by writing a 3cm line on the surface of the substrate [C1] with a hydrophilic transparent coating using a Mitsubishi oil marker (small piece red), and then running the ink for 3 minutes with running water. The rest was visually checked and evaluated. The evaluation criteria are shown below.
Ink completely falls: ◎ If ink looks closely, it remains: ○
Ink is slightly left: △ Ink is clearly left: ×

[Example 2]
[Standard particle size sunflower particles, small amount of resin, acrylic-styrene]
Preparation of Coating Solution for Coating Film [C2] To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 0.2 g of resin emulsion particle suspension [B1] (CG 8370 manufactured by DIC Corporation: particle size 100 nm: concentration 50 wt%, acrylic-styrene) was added, and then ethanol was added to obtain a solid content concentration of 5 wt. % And stirred with a magnetic stirrer at room temperature for 1 hour to obtain a coating liquid for film formation [C2]. The pH of the coating solution was 7.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [D2] A hydrophilic coated substrate [D2] was produced in the same manner as in Example 1 except that the coating film forming coating solution [C2] was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 3
[Standard particle size sunflower-like particles, large amount of resin, acrylic-styrene]
Preparation of Coating Solution for Forming Film [C3] 1.8 g of 5% silicic acid solution was added to 90 g of the sunflower-like particle dispersion [A1] and aged at 80 ° C. for 3 hours. Thereafter, 5 g of resin emulsion particle suspension [B1] (CG 8370 manufactured by DIC: particle size 100 nm: concentration 50 wt%, acrylic-styrene) was added, and then ethanol was added to adjust the solid content concentration to 5 wt%. Then, the mixture was stirred with a magnetic stirrer at room temperature for 1 hour to obtain a coating film forming coating solution [C3]. The pH of the coating solution was 7.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [D3] A hydrophilic coated substrate [D3] was produced in the same manner as in Example 1 except that the coating film forming coating solution [C3] was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 4
[Standard particle size sunflower-like particles, resin standard, emulsion particle size small, acrylic-styrene]
Preparation of emulsion resin particle suspension [B2] 1% hydrochloric acid and pure water were added to 100 g of resin emulsion particle suspension [B1] (CG 8370 manufactured by DIC: particle size 100 nm: concentration 50% by weight, acrylic-styrene). 250 g of a 20% diluted solution with a pH of 4.5 was prepared. Then, it stirred for 15 minutes at 1500 rpm using the homomixer, and prepared emulsion resin particle suspension [B2]. When this resin emulsion suspension [B2] was observed using TEM, it was a resin emulsion having an average particle diameter of 30 nm.
Preparation of Coating Solution for Coating Form [C4] To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 5 g of the resin emulsion particle suspension [B2] was added, and then ethanol was added to adjust the solid content concentration to 5 wt%, followed by stirring with a magnetic stirrer at room temperature for 1 hour for coating formation. A liquid [C4] was obtained. The pH of the coating solution was 6.0. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [D4] A hydrophilic coated substrate [D4] was produced in the same manner as in Example 1 except that the coating film forming coating solution [C4] was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 5
[Standard particle size sunflower particles, resin standard, acrylic-urethane]
Preparation of Coating Solution for Forming Film [C5] To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 2.22 g of resin emulsion particle suspension [B3] (CG-5010EF manufactured by DIC: particle size 100 nm: concentration 45 wt%, acrylic-urethane) was added, and then ethanol was added to obtain a solid content concentration of 5 The coating solution [C5] for film formation was prepared by stirring at room temperature for 1 hour with a magnetic stirrer. The pH of the coating solution was 7.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [D5] A hydrophilic coated substrate [D5] was produced in the same manner as in Example 1 except that the coating solution [C5] for forming a coated film was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 6
[Standard particle size sunflower particles, resin standard, acrylic-silicone]
Preparation of Coating Solution for Forming Film [C6] To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 2 g of resin emulsion particle suspension [B4] (SA-6360 manufactured by DIC: particle size 150 nm: concentration 50 wt%, acrylic-silicone) was added, and then ethanol was added to obtain a solid content concentration of 5 wt%. And stirred with a magnetic stirrer at room temperature for 1 hour to obtain a coating liquid for film formation [C6]. The pH of the coating solution was 8.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Manufacture of substrate [D6] with a hydrophilic coating A substrate [D6] with a hydrophilic coating was manufactured in the same manner as in Example 1 except that the coating solution [C6] for forming a coating was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 7
[Small particle sunflower-like particles, resin standard, acrylic-styrene]
Preparation of inorganic oxide particle (sunflower-like particle) dispersion [A2] ( Preparation of substrate particles)
150 g of cation exchange resin (manufactured by ROHMHARS: Duolite) is added to 750 g of silica sol (manufactured by JGC Catalysts & Chemicals: Cataloid SI-45P, average particle size 45 nm, surface potential -60 mV, SiO ₂ concentration 20 wt%, pH 10.2). Mix and stir at 30 ° C. for 0.5 h. Next, after separating the cation exchange resin, 135 g of an anion exchange resin (Mitsubishi Chemical Co., Ltd .: SUNUP-C) is mixed and stirred for 0.5 hour, and then the anion exchange resin is separated to obtain SiO _2. 750 g of purified silica sol having a concentration of 20% by weight was prepared. Next, 9.2 g of polyaluminum chloride (manufactured by Taki Chemical Co., Ltd .: Takibaine # 1000, Al ₂ O ₃ concentration 23.55 wt%) was added to 750 g of purified silica sol, and the mixture was stirred at room temperature for 0.5 hour. Next, 3661 g of a metal oxide particle dispersion [a-2] for a substrate made of silica having a SiO ₂ concentration of 4.1% by weight diluted with 2903 g of pure water was prepared. Subsequently, to the 3662 g of the metal oxide particle dispersion [a-2] for the substrate, silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd .: Cataloid SN-350, average particle diameter 7 nm, surface potential -23 mV, SiO ₂ concentration 16.6 wt% , PH 3.7) 595 g was mixed. At this time, the pH of the mixed dispersion was 3.5. Next, 135 g of an anion exchange resin (Mitsubishi Chemical Co., Ltd .: SUNUP-C) was mixed with the mixed dispersion and stirred for 0.5 hour. Then, the anion exchange resin was separated and the SiO ₂ concentration was measured by a rotary evaporator. An inorganic oxide particle (sunflower particle) dispersion [A2] composed of 10% by weight of silica was prepared. The pH of the dispersion was 6.5.
Preparation of Coating Solution for Coating Film [C7] Coating solution for coating film formation [C7] was obtained in the same manner as in Example 1 except that 90 g of the sunflower-like particle dispersion [A2] was used. The pH of the coating solution was 7.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [D7] A hydrophilic coated substrate [D7] was produced in the same manner as in Example 1 except that the coating film forming coating solution [C7] was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 8
[Kinpei particles, resin standard, acrylic-styrene]
Preparation of coating solution [C8] for coating film formation Dispersion of gold flat sugar silica (manufactured by JGC Catalysts & Chemicals Co., Ltd .: Cataloid CO-80A, average particle diameter 80 nm, specific surface area 43 m ² / g, surface potential −60 mV, SiO ₂ concentration 40% by weight , PH 10.2) A coating solution for forming a film [C8] was obtained in the same manner as in Example 1 except that 22.5 g was used. The pH of the coating solution was 9.5. Table 1 shows the concentration of confetti particles, the type of resin, the particle diameter of resin emulsion particles, the quantitative ratio of confetti particles to resin emulsion particles [competitive saccharide particles / (competitive saccharide particles + resin emulsion particles), solid content concentration, and pH.
Production of hydrophilic coated substrate [D8] A hydrophilic coated substrate [D8] was produced in the same manner as in Example 1 except that the coating film forming coating solution [C8] was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 9
[Porous particles, resin standard, acrylic-styrene]
Preparation of coating liquid for forming film [C9] Porous silica alumina particle dispersion (manufactured by JGC Catalysts & Chemicals Co., Ltd .: Cataloid USBB-120, average particle diameter 30 nm, specific surface area 800 m ² / g, concentration 20 wt%, pH 11.2) A coating solution for forming a film [C9] was obtained in the same manner as in Example 1 except that 22.5 g was used. The pH of the coating solution was 9.5. Table 1 shows the concentration of porous particles, resin type, particle diameter of resin emulsion particles, quantitative ratio of porous particles to resin emulsion particles [porous particles / (porous particles + resin emulsion particles), solid content concentration, pH] It was shown to.
Manufacture of substrate [D9] with hydrophilic coating A substrate [D9] with hydrophilic coating is manufactured in the same manner as in Example 1 except that the coating solution [C9] for forming a coating is used. The physical properties of the film were measured. The results are shown in Table 2.

Example 10
[Substrate change of Example 1]
Production of hydrophilic coated substrate [D10] A hydrophilic coated substrate [D10] was produced in the same manner as in Example 1 except that the substrate was used as a slate plate. Was measured. The results are shown in Tables 1 to 1.

Example 11
[Sunflower particle AgO composite, resin standard, acrylic-styrene]
Preparation of inorganic oxide particle (sunflower-like particle) dispersion [A3] ( Preparation of substrate particles)
750 g of silica sol (manufactured by JGC Catalysts & Chemicals Co., Ltd .: Cataloid SI-80P, average particle diameter 80 nm, surface potential -60 mV, SiO ₂ concentration 20 wt%, pH 10.2), 150 g of cation exchange resin (ROHMHARS: Duolite) Were mixed and stirred for 0.5 hour. Next, after separating the cation exchange resin, 135 g of an anion exchange resin (Mitsubishi Chemical Co., Ltd .: SUNUP-C) was mixed and stirred for 0.5 hour, and then the anion exchange resin was separated to obtain SiO ₂ concentration. 750 g of 20% by weight purified silica sol was prepared.
(Preparation of substrate particle dispersion)
To 750 g of the purified silica sol, 5.1 g of polyaluminum chloride (manufactured by Taki Chemical Co., Ltd .: Takibaine # 1000, Al ₂ O ₃ concentration 23.55 wt%) was added and stirred at room temperature for 0.5 hour. Subsequently, 2903 g of pure water was added and diluted to prepare 3658 g of a base particle dispersion liquid composed of silica having a SiO ₂ concentration of 4.1 wt%. The pH of the substrate particle dispersion was 3.7.
(Addition of fine particles)
3658 g of the substrate particle dispersion (SiO ₂ concentration: 4.1 wt%), AgO—SiO—Al ₂ O ₃ nanoparticles (manufactured by JGC Catalysts & Chemicals Co., Ltd .: ATOMY BALL UA average particle diameter of 10 nm, surface) as fine particles for coating 3253 g of an electric potential of −20 mV, a concentration of 1.5% by weight, and a pH of 7.0) were mixed. Thereafter, the solution was concentrated to 5.0 weight by a rotary evaporator.
(Preparation of sunflower-like particle dispersion)
135 g of an anion exchange resin (Mitsubishi Chemical Corporation: SUNUP-C) was mixed with the mixed dispersion, and the mixture was stirred for 0.5 hour, then the anion exchange resin was separated, and the SiO ₂ concentration was 10% by weight using a rotary evaporator. A sunflower-like particle dispersion [A3] comprising silica was prepared. The dispersion H was 7.0.
(Measurement of average particle diameter Dp)
The average particle diameter of the sunflower-like particles was taken as an average value obtained by taking a transmission electron micrograph (TEM) and measuring 10 major diameters.
(Measurement of coverage)
The dispersion of the sunflower-like particles was heated to 120 ° C. and dried, and the specific surface area of the sunflower-like particles was measured by the BET method to determine the coverage. The coverage was determined according to the above equation (4).
Preparation of Coating Solution for Forming Film [C11] To 90 g of the sunflower-like particle dispersion [A3], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 2 g of resin emulsion particle suspension [B1] (CG 8370 manufactured by DIC: particle size 100 nm: concentration 50 wt%, acrylic-styrene) was added, and then ethanol was added to adjust the solid content concentration to 5 wt%. Then, the mixture was stirred with a magnetic stirrer at room temperature for 1 hour to obtain a coating film forming coating solution [C11]. The pH of the coating solution was 7.5. Table 1 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [D11] A hydrophilic coated substrate [D11] was produced in the same manner as in Example 10 except that the coating film forming coating solution [C11] was used. The physical properties of the film were measured. The results are shown in Table 2.

Example 12
[Substrate change of Example 1]
Production of base material with hydrophilic coating [D12] The coating solution [A1] for coating formation was applied to nylon fibers (wire diameter 10 μm, pore diameter 1 μm) by the dipping method so that the dry layer thickness was the value shown in Table 1. The substrate [D12] with a hydrophilic film was produced by drying at 80 ° C. for 10 minutes, and the physical properties of the film were measured in the same manner as in Example 1. The results are shown in Table 2. The texture of nylon was confirmed. The texture was evaluated based on the hand touch before and after the coating film. The evaluation criteria are shown below.
The feel does not change before and after application: ◎
Slightly irritating after application: ○
Somewhat awkward after application: △
Clearly tingling after application: ×

Example 13
[Sunflower particle AgO composite, base material change]
Production of substrate [D13] with hydrophilic coating [C11] A coating solution [C11] for coating formation was applied to nylon fibers (wire diameter: 10 μm, pore diameter: 1 μm) by the dip method so that the dry layer thickness was the value shown in Table 1. The substrate [D13] with hydrophilic coating was produced by drying at 80 ° C. for 10 minutes, and the physical properties of the membrane were measured in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 1]
[Standard particle size sunflower-like particles, resin oligomer (non-emulsion)]
Preparation of Adhesive Layer Forming Coating Solution [R1] Modified alcohol (manufactured by Nippon Alcohol Sales Co., Ltd .: Solmix A-11, mixed alcohol of methanol, ethanol and isopropyl alcohol) 72.5 g of water 10.0 g and concentration of 61% by weight Nitric acid 0.1g was added and it stirred at 25 degreeC for 10 minutes. Then, 17.4 g of tetraethoxysilane (manufactured by Tama Chemical Industry Co., Ltd .: normal ethyl silicate-A, SiO ₂ concentration 28.8 wt%) was added and stirred at 30 ° C. for 30 minutes to hydrolyze tetraethoxysilane (solid A coating solution [R1] for forming an adhesive layer made of silica having a partial concentration of 5.0% by weight and a molecular weight of 1000) was prepared.
Preparation of coating solution [R2] for film formation To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 20 g of the adhesive layer forming coating solution [R1] was added, and then ethanol was added to adjust the solid content concentration to 5% by weight, followed by stirring with a magnetic stirrer at room temperature for 1 hour for coating forming. A liquid [R2] was obtained. The pH of the coating solution was 3.8. Table 3 shows the concentration of sunflower-like particles, the type of resin, the ratio of the amount of sunflower-like particles to the resin (sunflower-like particles / (sunflower-like particles + resin emulsion particles)), solid content concentration, and pH.
Production of hydrophilic coated substrate [R3] A hydrophilic coated substrate [R3] was produced in the same manner as in Example 1 except that the coating film forming coating solution [R2] was used. The physical properties of the film were measured. The results are shown in Table 4.

[Comparative Example 2]
[Standard particle size sunflower-like particles, no resin added]
Preparation of Coating Liquid for Coating Formation [L2] 1.8 g of 5% silicic acid solution was added to 90 g of the sunflower-like particle dispersion [A1] and aged at 80 ° C. for 3 hours. Thereafter, ethanol was added to adjust the solid content concentration to 5% by weight, and the mixture was stirred with a magnetic stirrer at room temperature for 1 hour to obtain a coating-forming coating solution [L2]. The pH of the coating solution was 7.5. Table 3 shows the concentration of sunflower-like particles, the type of resin, the ratio of the amount of sunflower-like particles to the resin (sunflower-like particles / (sunflower-like particles + resin emulsion particles)), solid content concentration, and pH.
Production of hydrophilic coated substrate [L3] A hydrophilic coated substrate [L3] was produced in the same manner as in Example 1 except that the coating liquid for coating film formation [L2] was used. The physical properties of the film were measured. The results are shown in Table 4.

[Comparative Example 3]
[Standard particle size sunflower-like particles, excess resin]
Preparation of Coating Solution for Coating Film [M2] To 90 g of the sunflower-like particle dispersion [A1], 1.8 g of 5% silicic acid solution was added and aged at 80 ° C. for 3 hours. Thereafter, 72 g of resin emulsion particle suspension [B1] (CG 8370 manufactured by DIC Corporation: particle size 100 nm: concentration 50 wt%, acrylic-styrene) was added, and then ethanol was added to obtain a solid content concentration of 5 wt%. The film was prepared and stirred with a magnetic stirrer at room temperature for 1 hour to obtain a coating liquid for forming a film (R3). The pH of the coating solution was 7.5. Table 3 shows the concentration of sunflower-like particles, the type of resin, the particle diameter of resin emulsion particles, the ratio of sunflower-like particles to resin emulsion particles [sunflower-like particles / (sunflower-like particles + resin emulsion particles), solid content concentration, pH. It was shown to.
Production of hydrophilic coated substrate [M3] A hydrophilic coated substrate [M3] was produced in the same manner as in Example 1 except that the coating film forming coating solution [M2] was used. The physical properties of the film were measured. The results are shown in Table 4.

[Comparative Examples 4 to 6]
[Physical properties of the substrate]
The physical properties of the substrates (glass, slate, nylon) used in Examples 1 to 13 were measured and are shown in Table 4.

1-Substrate, 2-Coating, 3-Particle Layer, 4-Adhesive Layer, 5-Inorganic Oxide Particle, 6-Water Drop, 10-Substrate with Super Hydrophilic Coating, 20-Sunflower Particle, 21-Substrate Particle 22-fine particles, 30-dispersion, 31-polar solvent, 32-resin emulsion particles, 33-polar solvent, 34-suspension.

Claims (22)

  A hydrophilic substrate having a superhydrophilic coating on the substrate surface, wherein the coating includes a particle layer containing inorganic oxide particles, a gap between the inorganic oxide particles, and the inorganic oxide particles and the substrate. The surface of the inorganic oxide particles is hydrophilic, and the surface of the inorganic oxide particles has an uneven structure exposed from the adhesive layer. A substrate with a super-hydrophilic coating. The average particle diameter (D _P ) of the inorganic oxide particles is 20 to 600 nm, the film thickness (U _F ) of the adhesive layer is 6 to 400 nm, and the average particle diameter (D _P ) of the inorganic oxide particles is The ratio (U _F / D _P ) of the film thickness (U _F ) of the adhesive layer is 1/3 to 2/3, and the average particle diameter (D _P ) of the inorganic oxide particles is 1/3 to 2 / The substrate with a superhydrophilic film according to claim 1, wherein 3 is exposed from the adhesive layer. The average height of the projections of the uneven structure of the hydrophilic coating surface _{(T F)} is in the range of 10 to 300 nm, the average distance between the convex portion (pitch) _{(W F)} is in the range of 1~1000nm The substrate with a superhydrophilic film according to any one of claims 1 and 2, wherein the substrate has a superhydrophilic film.   The substrate with a superhydrophilic film according to any one of claims 1 to 3, wherein the hydrophilic film has a thickness of 20 nm to 700 nm.   The substrate with super hydrophilic coating according to any one of claims 1 to 4, wherein the inorganic oxide particles are spherical, plate-shaped, confetti-shaped, or sunflower-shaped.   6. The substrate with a superhydrophilic film according to claim 5, wherein the inorganic oxide particles are spherical, plate-shaped, confetti-shaped, or sunflower-shaped and porous.   The inorganic oxide particles are sunflower-like particles composed of inorganic oxide substrate particles and inorganic oxide fine particles covering the surface of the substrate particles, and the inorganic oxide particle surfaces have fine irregularities due to the fine particles. The substrate with a superhydrophilic film according to any one of claims 1 to 6, wherein the substrate has a superhydrophilic film. The inorganic oxide particles have fine irregularities on the surface thereof, the average height of convex portions of the fine irregularities (T _FF ) is in the range of 0.5 to 10 nm, and the average distance between the convex portions of the fine irregularities ( The substrate with a superhydrophilic film according to any one of claims 1 to 7, wherein the pitch width (W _FF ) is in the range of 1 to 30 nm. The surface of the inorganic oxide particle is modified with a hydrophilic group by a hydrolyzable organosilicon compound represented by the formula of SiX ₄ (where X is a C 1-4 alkoxy group, hydroxyl group, halogen, hydrogen). The substrate with a superhydrophilic film according to any one of claims 1 to 8, wherein the substrate has a superhydrophilic film.   The contact angle with water is 10 degrees or less, The base material with a super hydrophilic film in any one of Claims 1-9 characterized by the above-mentioned. The inorganic oxide particles are selected from SiO ₂ , Al ₂ O ₃ , Sb ₂ O ₅ , ZrO ₂ , TiO ₂ , Fe ₂ O ₃ , CeO ₂ , AgO, CuO, Cu ₂ O, and complex oxides or mixtures thereof. The substrate with a superhydrophilic film according to any one of claims 1 to 10, wherein the substrate has at least one kind.   The adhesive layer is an emulsion resin, which is an ester resin, polycarbonate resin, amide resin, imide resin, polyphenylene oxide resin, acrylic resin, vinyl chloride resin, vinyl acetate resin, silicone resin, The substrate with a superhydrophilic film according to any one of claims 1 to 11, which is at least one selected from a urethane-based resin, a styrene-based resin, or a copolymer resin thereof.   A coating solution for forming a superhydrophilic film, characterized in that inorganic oxide particles having hydrophilic particle surfaces and resin emulsion particles are mixed and monodispersed in a polar solvent. The superhydrophilic film according to [13], wherein the average particle size (De) of the resin emulsion particles is equal to or smaller than the average particle size (D _P ) of the inorganic oxide particles (De ≦ D _P ) Coating liquid for forming.   [13] The quantitative ratio (G / [G + M]) between the amount (G) of inorganic oxide particles and the amount (M) of resin emulsion particles is in the range of 0.5 to 0.98. ] Or the coating solution for forming a superhydrophilic film described in [14] above.   It consists of two liquids, a dispersion liquid in which inorganic oxide particles having hydrophilic particle surfaces are dispersed in a polar solvent and a suspension liquid in which resin emulsion particles are suspended in a polar solvent, and the dispersion liquid and the suspension are mixed. The coating solution for forming a super-hydrophilic film according to any one of [13] to [15], wherein the inorganic oxide particles and the resin emulsion particles are mixed and monodispersed in a polar solvent.   A coating solution for forming a film in which inorganic oxide particles having hydrophilic particle surfaces and resin emulsion particles are dispersed and suspended in a polar solvent is applied to a base material, and the resin emulsion is placed in the gap between the inorganic oxide particles. A particle layer in which particles are interposed is formed, and after application, heated and dried, and the resin emulsion particles are collapsed to allow the resin to enter the gap between the inorganic oxide particles and the gap between the inorganic oxide particles and the substrate. Forming a superhydrophilic film having a concavo-convex structure in which the upper part of the inorganic oxide particles is exposed from the adhesive layer on the base material. Method.   A coating in which a dispersion of inorganic oxide particles having a hydrophilic particle surface is mixed with a suspension of resin emulsion particles, and the inorganic oxide particles and resin emulsion particles are mixed and monodispersed in a polar solvent. The manufacturing method of the base material with a superhydrophilic film of Claim 17 which prepares the coating liquid for formation and apply | coats this coating liquid to a base material. The average particle diameter (De) of the resin emulsion particles contained in the coating liquid for forming a film is equal to or smaller than the average particle diameter (D _P ) of the inorganic oxide particles (De ≦ D _P ), or The manufacturing method of the base material with a superhydrophilic film of Claim 18.   The amount ratio (G / [G + M]) of the amount of inorganic oxide particles (M) and the amount of resin emulsion particles (E) contained in the coating liquid for forming a film is in the range of 0.5 to 0.98. The method for producing a substrate with a superhydrophilic film according to any one of claims 17 to 19, wherein:   As emulsion resins, ester resins, polycarbonate resins, amide resins, imide resins, polyphenylene oxide resins, acrylic resins, vinyl chloride resins, vinyl acetate resins, silicone resins, urethane resins, or styrene A resin emulsion particle suspension obtained by suspending resin emulsion particles composed of a resin or a copolymer resin thereof in a polar solvent, and an inorganic oxide particle dispersion obtained by dispersing inorganic oxide particles in a polar solvent. 21. The method for producing a substrate with a superhydrophilic film according to any one of claims 17 to 20, wherein a coating liquid for forming a film is prepared. The superhydrophilic coating film according to any one of claims 17 to 21, wherein the coating emulsion is applied to a substrate and then dried by heating to 60 to 200 ° C to disintegrate the resin emulsion particles. A method for producing a substrate.

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