JP2000336336A - Hydrophilization of substrate or substrate surface, substrate having hydrophilic surface, its production and composition capable of imparting hydrophilicity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hydrophilize a substrate or a substrate surface without using a photocatalytic material or photoexcitation by forming a surface layer from a composite material containing silica and alumina on the substrate or substrate surface. SOLUTION: A surface layer is formed from a composite material containing silica and alumina on a substrate (e.g. a synthetic resin coating material, a screen printing ink or a polyethylene pellet) or the substrate surface to thereby hydrophilize the substrate or substrate surface (a state wetted with water at <=10 deg. expressed in terms of contact angle with water). For example, the composite material containing the silica and alumina is uniformly kneaded with the substrate to form the substrate or the surface layer of the substrate. The formed substrate, as necessary, is baked at 80-1,200 deg.C temperature and thereby solidified. A surface layer containing moderately containing the silica, alumina, synthetic resin coating material and a highly viscous polymeric gel (alginic acid or sodium alginate) may be formed on the surface of the substrate (e.g. a PET film).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for making and maintaining a substrate or a surface of the substrate hydrophilic. More specifically, the present invention relates to a technique for preventing the surface from being soiled, or performing self-cleaning or easily cleaning by making the surface of a base material or a base material of a building or a structure hydrophilic. The present invention also provides
The present invention relates to a technology for preventing fogging and formation of water droplets by making a mirror, glass, resin, or other transparent substrate or the surface of the substrate hydrophilic.

[0002]

2. Description of the Related Art Contamination of exterior materials and coatings of buildings or structures is caused by the collection of particulates such as automobile exhaust gas and soot on the roof and outer walls of buildings. Contaminants adhere down the building's outer walls, along the path of rainwater, and when the surface dries, striped dirt becomes noticeable.

It has also been proposed to make the surface hydrophilic in order to prevent clouding and the formation of water droplets. For example, Japanese Patent No. 2756474 discloses a composite material comprising a photocatalytic film containing a base material, a photocatalytic material, and silica, wherein the surface of the film has hydrophilicity in response to photoexcitation. There is. However, in this method, a photocatalytic material (titanium oxide or the like) that hydrophilizes the surface of the coating film by photocatalysis is used. Therefore, when the base material is dark, the titanium oxide particles can be visually observed, so that only a light color can be adopted. . In addition, photoexcitation (ultraviolet irradiation) is required, and special considerations are required indoors and in places where irradiation with sunlight is insufficient.

[0004]

As described above, by making the surface of the base material hydrophilic, it is possible to prevent the exterior material or the coating film serving as the surface of a building or a structure from being stained, or to purify or easily purify the surface. Although there are proposals to clean the substrate and prevent clouding of the substrate and formation of water droplets, there are many problems in forming hydrophilicity on the substrate surface. In view of the above circumstances, the present invention has been made to solve the problem simply and inexpensively, and is intended to provide a photocatalytic material (such as titanium oxide).
And the discovery that the surface is made hydrophilic by forming a surface layer with a substrate or a composite containing silica and alumina on the substrate surface without the need for light excitation (ultraviolet radiation).

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a method for forming a surface layer on a substrate or a mixture containing finely divided silica and finely divided alumina on a surface of the substrate by placing water on the surface. Usually, water droplets are formed.Since silica is hydrophobic and alumina is hydrophilic, water is finely dispersed in a hydrophobic part and a hydrophilic part like a checkered pattern.
This is considered to be due to the phenomenon of forming a hydrophilic film that looks as if a water film is formed on one surface.

[0006] By adding an antifogging composition containing a water repellent compound such as polyethylene glycol or silicone as a hydrophilic compound and mixing it with finely divided silica or finely divided alumina, water becomes hydrophobic. Finely dispersed in a hydrophilic part and a hydrophilic part to obtain a highly hydrophilic film. Therefore, no visible water droplets are formed on the surface of the transparent substrate such as glass, lens, and mirror, and therefore, the surface of the transparent substrate does not fog.

[0007] High viscosity polymer gels include alginic acid,
Sodium alginate, calcium alginate, PA
A, PVA, NIPAM, PVA-PAA and the like.
In particular, sodium alginate is obtained as a highly viscous precipitate by treating a dried sodium carbonate extract of a seaweed with an acid, and gradually dissolves in water like glue to become an extremely viscous liquid. In particular, it is preferable that the organic substance is contained in a base material of a heat-sensitive organic substance or added to a mixture to be coated, and the base material or the coating film is firmly fixed. Therefore, it is possible to eliminate the necessity of a firing step for fixing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, in a first embodiment of the present invention, silica and alumina are moderately kneaded in a synthetic resin paint as a base material, and a hydrophilic layer is formed on the base material or the base material surface. Are formed. In the second embodiment, as shown in FIG.
Silica and alumina are appropriately kneaded in the screen printing ink serving as a base material, and a hydrophilic layer is formed on the base material or the base material surface. In the third embodiment, as shown in FIG.
Silica, alumina, polyethylene pellets
Silicone, high-viscosity polymer gel, and polyethylene glycol are appropriately kneaded, and a hydrophilic layer is formed on the substrate or the surface of the substrate. In the fourth embodiment, as shown in FIG. 4, silica, alumina,
A surface layer containing a moderate amount of a synthetic resin paint and a high-viscosity polymer gel is formed, and the base material surface is hydrophilic. In the fifth embodiment, as shown in FIG. 5, a surface layer containing moderately silica, alumina, polysol, and polyethylene glycol is formed on the surface of a base material (decorative plywood), and the base material surface becomes hydrophilic. ing. In the sixth embodiment, as shown in FIG. 6, silica, alumina, silicone, and glaze (primer A) are provided on the surface of a base material (stainless steel plate).
A moderately contained surface layer is formed, and the substrate surface is hydrophilic. In the seventh embodiment, as shown in FIG. 7, a surface layer containing moderately silica, alumina, polyethylene glycol, and glaze (primer A) is formed on the surface of a substrate (glass plate). Has become hydrophilic.

The hydrophilicity in the present invention means a state of water wettability of 10 ° or less in terms of a contact angle with water. If the surface of the base material is in a state of being equal to or less than 10 ° in terms of a contact angle with water, a dust or a combustion product contained in exhaust gas of an automobile or the like becomes a surface of a building or a structure. It becomes difficult to adhere to the film or the coating film, and even if it adheres, it can be easily cleaned by self-purification by rainfall or washing with water.

When the surface of the base material is in a state of being 10 ° or less in terms of a contact angle with water, the pseudo-water can individually form water droplets even if moisture or steam in the air is dewed. No light scattering that causes fogging occurs. Therefore, visibility of a bathroom mirror, a curve mirror, and the like is secured.

As a substrate to which the present invention can be applied, most of the materials which are expected to have an antifouling effect are theoretically possible except for water and air. Speaking of specific applications, siding materials, tiles, glass, sashes, screen doors, shutters, gates, carports, sunrooms, veranda handrails, roofing materials, building sashes, painted steel plates, aluminum panels,
Stone materials, tunnel interior boards, tunnel lighting, road signs, road signs, road information boards, road lighting, soundproof walls, guard fences, road decorative boards, road reflectors, elevated roads, bullet trains, trains, buses, trucks, passenger cars, light vans, airplanes , Rocket, amusement park gondola, ropeway gondola, motorcycle, snowmobile, passenger ship, cargo ship, fishing boat, submarine, bridge, watchtower, TV tower, parking lot, steel tower, tent, shopping arcade and information board, notice board , Advertising towers, housing equipment, tableware,
Dishwasher, dish dryer, countertop, sink, kitchen utensils, ventilation fan, cooking range, kitchen hood, ceiling, wall, flooring, vanity, bathtub, bathroom, unit bath, toilet, etc. Thus, there are countless substrates that are expected to have an antifouling function. The substrate and shape are not particularly limited, and any surface may be painted, painted, or written on the surface, as long as it is necessary and employed to constitute the base material. For example, iron, cast iron, non-ferrous metal, resin, cement, tile, ceramic, plastic, concrete, glass, ceramics, fiber, plywood, wood,
It may be a stone or the like, or a combination or a laminate of these. Further, a film to be attached to the surface of the article is also included.

When an antifogging effect is expected on the substrate and the substrate surface, a transparent substrate is used. Glass, resin, etc. can be optimally used as the material. Speaking of applicable base materials, there are mirrors for bathrooms, mirrors for toilets, rearview mirrors for vehicles, curve mirrors, other lenses, carports, sunrooms, window glasses, etc. A film for application is also included.

The method for forming a hydrophilic substrate shown in FIGS. 1, 2 and 3 is, for example, a method in which a composite containing silica and alumina and a substrate are uniformly kneaded to form a substrate or a substrate surface layer. I have. 80 ° C. to 1200 ° C.
By solidifying at a temperature of Furthermore, even if the solidified substrate surface is shaved, a new hydrophilic substrate surface is constructed.

As a method of forming the hydrophilic substrate surface layer shown in FIGS. 4, 5, 6, and 7, for example, the thickness of the surface layer may be 1 nm or more, and there is no particular upper limit. However, when it is desired to coat a transparent substrate surface and coat in a transparent state, the thickness is preferably 1 μm or less. The thinner the film, the better. If it is thinner, it prevents the surface layer from being darkened by light absorption, ensures the transparency of the base material, and improves the wear resistance.

Next, as a method for forming the surface of the hydrophilic substrate, for example, a mixed solution containing silica, alumina, a high-viscosity polymer gel, polyethylene glycol, or part or all of silicone is sprayed on the surface of the substrate. There are methods such as coating, spin coating, dip coating, roll coating, and flow coating.

After coating by the above method, if necessary, a method of baking at a temperature of 80 ° C. to 1200 ° C. at which a mixed solution layer containing silica and alumina crystallizes to fix the surface layer to the substrate is preferable. It is.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. Embodiment 1 FIG. A method for making a base material hydrophilic, in which 20 g of a synthetic resin (modified alkyd) paint / black (Dainippon paint / oiliness) serving as a base material is mixed with silica / Aerosil 200 (Nippon Aerosil) 0.1749 and alumina / Degussa 0.026 g of aluminum oxide C (Degussa, Germany) was mixed and sufficiently stirred to obtain a mixed base material. The total content ratio of silica and alumina in the synthetic resin paint was set to 1% at 0.2 g. Here, 87% silica: 13% alumina
Of the mixture. Next, a 20 μm-thick film was applied to the surface of a 10 × 15 cm square veneer (Masawa plywood, type I) using a paint roller, and # was used as the base material.
For comparison, a synthetic resin (modified alkyd) paint used for preparing # 1 sample, black <Dai Nippon Paint Co., Ltd., was applied to the surface of a 10 × 15 cm square veneer (Masuzawa Plywood, Type I) for comparison.
Oiliness> was applied with a paint roller to a film thickness of 20 μm to obtain a # 2 sample. After air drying for 8 hours (room temperature of 20 ° C.), the surface of each sample showed that the # 2 sample was water repellent by 10 ° or more, and the # 1 sample became hydrophilic. Incidentally, the contact angle with water was 3 °. Here, the contact angle with water was measured by a contact angle measuring device (Kyowa Interface Science, CA-x150) after dropping a water drop from the spoid onto the sample surface and 60 seconds later.
Next, in order to confirm the influence of the presence or absence of light on the # 1 sample, the measurement was performed by leaving the sample in a dark place for 7 days. As a result, the contact angle is 3 °
There was no change. Then, using an ultraviolet light source (DAIKO ultraviolet lamp, 100 W), the illuminance was 1.6 mW / cm.
^The measurement was performed after irradiating ultraviolet light of No. ² for 12 hours. as a result,
It was confirmed that the contact angle was 3 ° and was not affected by light. Further, after polishing the substrate surface of the # 1 sample by 5 μm,
A drop of water was dropped on the surface with a spoid, and measured 60 seconds later, it showed 5 ° and it was confirmed that hydrophilicity was secured.

Embodiment 2 FIG. A method for making a substrate hydrophilic, in which 20 g of a screen printing ink clear (Jujo Ink), which is a substrate, 0.15 g of silica / Aerosil 200 (Nippon Aerosil) and alumina / degussa aluminum oxide C (Germany) Degussa> 0.05 g was mixed and sufficiently stirred to obtain a mixed base material. The total content of silica and alumina in the screen printing ink is 0.2 g
To be 1%. Here, the mixing ratio was 75% silica: 25% alumina. Then 10 × 15cm
The surface of a square polystyrene foam plate <Mitsuishi Sangyo> is coated by screen printing with a film thickness of 12 μm to make a # 3 sample as the base material. For comparison, a 10 × 15 cm square polystyrene foam plate <Mitsuishi Sangyo> A surface having a film thickness of 12 μm was screen-printed on the surface of <1> with the screen printing ink clear (Jujo Ink) used for preparing the # 3 sample to prepare a # 4 sample. After 8 hours of natural drying (room temperature 20 ° C.), the surface of each sample shows that the # 4 sample is more than 10 ° water repellent,
Three samples became hydrophilic. By the way, the contact angle with water is 2 °
showed that. Here, the contact angle with water was measured by a contact angle measuring device (Kyowa Interface Science, CA-x150) after dropping a water drop from the spoid onto the sample surface and 60 seconds later. Next, in order to confirm the influence of the presence or absence of light on the # 1 sample, the measurement was performed by leaving the sample in a dark place for 7 days. As a result, the contact angle was 2 ° and did not change. Next, an ultraviolet light source (DAIKO ultraviolet lamp,
100 W), and irradiation was performed for 12 hours with ultraviolet light having an illuminance of 1.6 mW / cm ² for measurement. As a result, the contact angle is 2
It was confirmed that the sample was not affected by light at all. Further, after polishing the surface of the base material of the # 3 sample by 5 μm, a water drop was dropped on the surface by a spoid.
° indicates that the hydrophilicity was ensured.

Embodiment 3 FIG. A method for making a substrate hydrophilic, wherein the substrate is a polyethylene pellet (Nakada Sangyo) 2
0 g of silica / Aerosil 200 <Nippon Aerosil>
0.1 g of alumina / degussa aluminum oxide C (Degussa, Germany) was mixed and mixed sufficiently to obtain a mixed base material. The total content ratio of silica and alumina in the polyethylene pellets was set to 1% at 0.2 g. Here, the mixing ratio was 50% silica: 50% alumina. Then, it is formed into a 5 × 5 × 0.5 cm square plate, left at room temperature (room temperature 16 ° C.) for 24 hours and dried,
A # 5 sample as a substrate was obtained. For comparison, polyethylene pellets (Nakada & Co., Ltd.)
Formed on a × 5 × 0.5cm square plate, room temperature (room temperature 16 ° C)
For 24 hours, and dried to obtain a # 6 sample as a substrate. On the surface of each sample after solidification, the # 6 sample was water-repellent by 10 ° or more, and the # 5 sample became hydrophilic. Incidentally, the contact angle with water was 5 °. Here, the contact angle with water was measured 60 seconds after a water drop was dropped on the sample surface from the spoid by a contact angle measuring device (Kyowa Interface Science, CA-x150). Next, in order to confirm the influence of the # 5 sample due to the presence or absence of light, the sample was left in a dark place for 7 days and measured. As a result, the contact angle was 5 ° and did not change. Next, an ultraviolet light source (DA
Using an IKO ultraviolet lamp (100W), the illuminance is 1.6
The measurement was performed after irradiation with mW / cm ² ultraviolet rays for 12 hours.
As a result, it was confirmed that the contact angle was 5 ° and was not affected by light. Further, the base material of the # 5 sample, 5 × 5 × 0.5
After the surface of the 0.1 cm square plate was polished by 0.1 mm, a water drop was dropped on the surface with a spoid, and measured after 60 seconds.
° indicates that the hydrophilicity was ensured.

Embodiment 4 FIG. A method for making the surface of a substrate hydrophilic, comprising a synthetic resin (acrylic) paint / aqueous transparent clear (Nippon Paint) 10 ml, distilled water 10 ml, sodium alginate which becomes a high-viscosity polymer gel <Wako Pure Chemical>
0.1 g of silica / Aerosil 200 (Nippon Aerosil) and 0.03 g of alumina / Degussa aluminum oxide C (Germany Degussa) were added to a well-mixed solution mixed with 0.1 g, and stirred well. A coating liquid was obtained. The total content of silica and alumina in the mixed solution was adjusted to about 0.5% with 0.1 g. Here, the mixing ratio was 70% silica and 30% alumina. Next, a 5 × 10 cm square transparent PET substrate
The coating solution was applied to a film thickness of 0.3 μm on the surface of the film <Nippon Soda>, and dried at normal temperature (room temperature 15 ° C.) for 3 hours to obtain a # 7 sample. However, there was no color development due to the surface layer. For comparison, the mixed solution used for preparing the # 8 sample was applied to the surface of a 5 × 10 cm square transparent PET film (Nippon Soda) to a thickness of 0.3 μm, and dried at room temperature (room temperature 15 ° C.) for 3 hours. As a result, a # 8 sample was obtained. The surface of each sample, # 8 sample has water repellency of 10 ° or more,
Seven samples became hydrophilic, and the contact angle with water was 8 °. Here, the contact angle with water was measured 60 seconds after a water drop was dropped on the sample surface from the spoid by a contact angle measuring device (Kyowa Interface Science, CA-x150). Next, in order to confirm the influence of the presence or absence of light on the # 7 sample, the sample was left in a dark place for 7 days and measured. As a result, the contact angle was 8 ° and did not change. Next, an ultraviolet light source (DAIKO ultraviolet lamp 1)
00W), ultraviolet light having an illuminance of 1.6 mW / cm ² was irradiated for 12 hours, and then measured. As a result, the contact angle is 8 °
It was confirmed that the sample was not affected by light at all.

Embodiment 5 FIG. A method of making the surface of a substrate hydrophilic, comprising mixing a polysol / aqueous <Showa polymer> 8 ml, polyethylene glycol 200 <Wako Pure Chemical> 2 ml, and distilled water 10 ml, and stirring the mixed solution to silica. / Aerosil 200 (Nippon Aerosil) 0.06 g and alumina / Degussa aluminum oxide C (Degussa, Germany) 0.04 g were added and stirred well to obtain a coating solution. The total content ratio of silica and alumina in the mixed solution was 0.5 g for 0.1 g, and here, the mixing ratio was 60% silica: 40% alumina. Next, 5 × 10cm square decorative plywood as a base material <National Building Materials>
The above coating solution was applied to a thickness of 0.2 μm on the surface of, and dried at room temperature (room temperature of 15 ° C.) for 8 hours to obtain a # 9 sample. However, there was no color development due to the surface layer. 5 × 1 mixed solution used to make # 9 sample for comparison
0.2μm on 0cm square decorative plywood <National Building Materials>
And dried at room temperature (room temperature 15 ° C.) for 8 hours to obtain a # 10 sample. On the surface of each sample, the # 10 sample had water repellency of 10 ° or more, the # 9 sample became hydrophilic, and the contact angle with water was 2 °. Here, the contact angle with water is measured using a contact angle measuring device (Kyowa Interface Science, CA- × 1).
According to 50), a drop of water is dropped from the spoid onto the sample surface, and 6
It was measured after 0 seconds. Next, in order to confirm the influence of the # 9 sample due to the presence or absence of light, the sample was left in a dark place for 7 days and measured. As a result, the contact angle did not change at 2 °. Next, measurement was performed after irradiating with ultraviolet light having an illuminance of 1.6 mW / cm ² for 12 hours using an ultraviolet light source (DAIO ultraviolet lamp / 100 W). As a result, it was confirmed that the contact angle was 2 ° and was not affected by light.

Embodiment 6 FIG. This is a method for making the surface of a substrate hydrophilic, comprising 4 ml of glaze / primer A (col coat).
16 ml of isopropyl alcohol (Takara Chemical Co., Ltd.) and 0.1 g of silicone / methyltrimethoxysilane were mixed, and the mixed solution was sufficiently stirred and mixed with silica / Aerosil 2
00 <Nippon Aerosil> 0.05g and Alumina / Degussa aluminum oxide C <Germany Degussa> 0.0
5 g was added, and the mixture was stirred well to obtain a coating liquid. The total content of silica and alumina in the mixed solution is 0.1
g and 0.5%, and here, the mixing ratio was 50% silica: 50% alumina. Next, the above coating solution was applied to a 5 × 10 cm square stainless steel mirror-finished plate <Nippon Special Steel> to a thickness of 0.1 μm and baked at a temperature of 150 ° C. for 30 minutes to obtain a # 11 sample. However, no color development by the surface layer was observed. For comparison, the mixed solution used for preparing the # 11 sample was applied to a 5 × 10 cm square stainless steel mirror-finished plate (Japan Special Steel) to a thickness of 0.1 μm, and baked at a temperature of 150 ° C. for 30 minutes. Thus, a # 12 sample was obtained. The contact angle of each sample surface with water after firing was # 1
Two samples had water repellency of 10 ° or more, whereas # 11
The sample showed a value of 3 °. Here, the contact angle with water was measured 60 seconds after a water drop was dropped on the sample surface from the spoid by a contact angle measuring device (Kyowa Interface Science, CA-x150). Next, in order to confirm the influence of the presence or absence of light on the # 11 sample, the sample was left in a dark place for 7 days and measured. As a result, the contact angle was 3 ° and did not change. Next, an ultraviolet light source (DAI
Illuminance 1.6m using KO UV lamp 100W)
The measurement was performed after irradiating with W / cm ² ultraviolet rays for 12 hours. As a result, it was confirmed that the contact angle was 3 ° and was not affected by light.

Embodiment 7 FIG. This is a method for making the surface of a substrate hydrophilic, comprising 4 ml of glaze / primer A (col coat).
A mixture of 15 ml of isopropyl alcohol (Takara Chemical Co., Ltd.) and 1 ml of polyethylene glycol 200 (Wako Pure Chemical) was mixed well and mixed with silica / Aerosil 2
00 <Japan Aerosil> 0.089 and Alumina / Degussa aluminum oxide C <Degussa Germany> 0.0
29 was added and stirred well to obtain a coating solution. The total content of silica and alumina in the mixed solution is 0.1
g, 0.5%, and here, the mixing ratio was 80% silica: 20% alumina. Next, the above coating solution was applied to a 5 × 10 cm square stainless steel mirror-finished plate <Nippon Special Steel> to a thickness of 0.05 μm and baked at a temperature of 150 ° C. for 30 minutes to obtain a # 13 sample. However, no color development by the surface layer was observed. For comparison, the mixed solution used in preparing the # 13 sample was applied to a 5 × 10 cm square stainless steel mirror-finished plate (Japan Special Steel) to a thickness of 0.05 μm, and baked at a temperature of 150 ° C. for 30 minutes. As a result, a # 14 sample was obtained. The contact angle of each sample surface with water after firing is
The # 14 sample had a water repellency of 10 ° or more,
Thirteen samples showed a value of 1 °. Where the contact angle with water is
A water drop was dropped on the sample surface from the spoid using a contact angle measurement device (Kyowa Interface Science, CA-x150), and measurement was made 60 seconds later. Next, in order to confirm the influence of the # 13 sample due to the presence or absence of light, the sample was left in a dark place for 7 days and measured. As a result, the contact angle was 1 ° and did not change. Next, an ultraviolet light source (D
Using an AIKO ultraviolet lamp (100 W), the illuminance was 1.
The measurement was performed after irradiation with 6 mW / cm ² ultraviolet rays for 12 hours. As a result, it was confirmed that the contact angle was 1 ° and was not affected by light.

[0024]

The present invention makes it difficult for dust and combustion products contained in exhaust gas from automobiles and the like to adhere to exterior materials and coatings that become surfaces of buildings or structures. Alternatively, hydrophilicity that can be easily cleaned by washing with water, and antifogging that does not cause light scattering that causes fogging, even if moisture or steam in the air condenses, without simulated water forming individual water droplets Sex can be maintained permanently.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a first embodiment according to the present invention.

FIG. 2 is a diagram showing an embodiment of a second embodiment according to the present invention.

FIG. 3 is a diagram showing an embodiment of a third embodiment according to the present invention.

FIG. 4 is a diagram showing an embodiment of a fourth embodiment according to the present invention.

FIG. 5 is a diagram showing an embodiment of a fifth embodiment according to the present invention.

FIG. 6 is a diagram showing an embodiment of a sixth embodiment according to the present invention.

FIG. 7 is a diagram showing an embodiment of a seventh embodiment according to the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/36 C08K 3/36 C08L 71/02 C08L 71/02 83/04 83/04 101/14 101 / 14 C09D 7/12 C09D 7/12 Z 171/02 171/02 183/04 183/04 201/00 201/00 C09K 3/18 C09K 3/18

Claims (13)

[Claims] 1. A method of making a substrate or a surface of the substrate hydrophilic, wherein the substrate is mixed with silica and alumina to form the substrate. 2. A method for making a surface of a substrate or a substrate hydrophilic, comprising forming a surface layer containing silica and alumina on the substrate. 3. The method according to claim 1, further comprising a highly viscous polymer gel, wherein the substrate or the surface of the substrate is made hydrophilic. 4. The method for making a substrate or the surface of a substrate hydrophilic according to claim 1, comprising polyethylene glycol. 5. The method for making a substrate or the surface of a substrate hydrophilic according to claim 1, wherein the substrate comprises silicone. 6. A substrate having a hydrophilic surface, characterized in that a substrate is mixed with silica and alumina to form a substrate, and the substrate forms a surface layer containing silica and alumina. Wood. 7. A substrate having a hydrophilic surface, wherein a surface layer containing silica and alumina is formed on the surface of the substrate. 8. The substrate having a hydrophilic surface according to claim 7, wherein the thickness of the surface layer containing silica and alumina is 1 nm or more. 9. A step of forming a base material by mixing the base material with silica and alumina, and a step of firing at a temperature of 80 ° C. to 1200 ° C. to form a mixed base material containing the base material and silica and alumina. And a method for producing a substrate having a surface of a hydrophilic housing. 10. A step of coating a substrate surface with a mixed solution containing silica and alumina, at a temperature of 80 ° C. to 1200
B. Forming a mixed solution layer containing silica and alumina by baking at a temperature of ° C. to produce a substrate having a hydrophilic surface. 11. A step of coating a mixed solution layer containing silica and alumina on the surface of a base material, from 80 ° C. to 1200 ° C.
B. Sintering at a temperature of ° C. to crystallize a mixture containing silica and alumina, and forming a mixture containing silica and alumina, a method for producing a substrate having a hydrophilic surface. 12. A base material comprising a base material and a mixture containing silica and alumina, forming a base material,
A composition for imparting hydrophilicity to a mixed substrate containing silica and alumina by firing at a temperature of 0 ° C. 13. A mixed solution containing silica and alumina, which is coated on a substrate and baked at a temperature of 80 ° C. to 1200 ° C. to give hydrophilicity to a mixed solution layer containing silica and alumina. .