JP3298439B2 - Photocatalytic hydrophilic coating liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrophilic coating liquid for forming a coating film capable of making and maintaining the surface of a member highly hydrophilic. More specifically, the present invention provides a highly hydrophilic surface of a mirror, glass, lens, prism or other transparent member to form a coating film capable of preventing clouding and water droplet formation of the member. It relates to an antifogging coating liquid. The present invention also provides a coating film capable of preventing the surface from being soiled or cleaning the surface with water by highly hydrophilizing the surface of a building, a window glass, a mechanical device or an article. The present invention relates to an easy-to-clean coating liquid for forming a liquid.

[0002]

BACKGROUND OF THE INVENTION It is often experienced that in cold weather, windshields and glazings of automobiles and other vehicles, glazings of buildings, lenses of eyeglasses, and cover glass of various instrument panels are fogged by condensed moisture. . In addition, mirrors and eyeglass lenses in bathrooms and washrooms are often fogged by steam. The fogging on the surface of the article is that if the surface is placed at a temperature below the dew point of the atmosphere, the moisture in the atmosphere will condense and condense on the surface,
This is because they grow like water drops. If the condensed water droplets are sufficiently fine and their diameter is about half the wavelength of visible light, the water droplets will scatter light and the glass or mirror will be apparently opaque, again losing visibility. If the condensation of moisture progresses further and the fine condensed water droplets fuse together and grow into larger discrete water droplets, their surfaces will be refracted by the refraction of light at the water droplet-surface interface and the water droplet-air interface. Dark, blurred, mottled or cloudy. as a result,
In a transparent article such as glass, the perspective image is distorted and the transparency is reduced, and the reflected image is disturbed by a mirror. Furthermore, windshields and window glasses of vehicles, window glasses of buildings, back mirrors of vehicles,
If eyeglass lenses, masks, or helmet shields are subjected to rainfall or splashes, and a large number of discrete water droplets adhere to the surface, those surfaces may become dark, blurred, mottled, or cloudy, and still lose visibility. Will be As used herein, the term "anti-fog" broadly refers to a technique for preventing optical hindrance due to such fogging, growth of condensed water droplets, and adhesion of water droplets. Needless to say, the above "clouding" has a profound effect on safety and efficiency of various operations. For example, if the windshield or window glass of the vehicle or the back mirror of the vehicle is shaded or clouded in cold weather or rainy weather, it is difficult to secure a view, and traffic safety is impaired. If the focusing lens of the endoscope lens, dental mirror, or dental laser treatment device becomes cloudy, accurate diagnosis,
It will hinder surgery and treatment. If the cover glass of the instrument panel becomes fogged, it becomes difficult to read the data.

On the other hand, in the field of construction and paints, stains on building exterior materials, outdoor buildings and their coatings have become a problem with environmental pollution. Dust and particles suspended in the air accumulate on the roof and outer walls of buildings in fine weather. Sediment is washed away by rainwater as it rains and flows down the building's outer walls. Furthermore, in the rain, the floating dust is carried by the rain and flows down on the outer wall of the building or the surface of the outdoor building. As a result, pollutants adhere to the surface along the path of rainwater. When the surface dries, striped stains appear on the surface. Soil on building exterior materials and coatings consists of combustion products such as carbon black and inorganic contaminants such as urban dust and clay particles. It is considered that the diversity of such contaminants complicates antifouling measures (Yoshinori Tachibana, "Method of Accelerated Testing of Contamination of Exterior Wall Finishing Materials", Journal of Architectural Institute of Japan, Structural Transactions, No. 404, October 1989, pp. 15-2
4). According to conventional wisdom, polytetrafluoroethylene (PTFE) is used to prevent the above-mentioned dirt on the building exterior.
Although water-repellent paint such as was considered preferable,
Recently, for urban dust containing many hydrophobic components,
It is considered that the surface of the coating film should be made as hydrophilic as possible (Polymer, vol. 44, May 1995, p. 3).
07). Therefore, it has been proposed to paint a building with a hydrophilic graft polymer (newspaper "Chemical Industry Daily",
Jan. 30, 1995). According to reports, this coating exhibits a hydrophilicity of 30 to 40 ° in contact angle with water.
However, the contact angle of inorganic dust represented by clay minerals with water is 20 ° to 50 °, and the contact angle with water is 3 °.
Having an affinity for a graft polymer of 0 to 40 °;
It is considered that the graft polymer coating cannot prevent contamination by inorganic dust because it easily adheres to the surface.

[0004]

An object of the present invention is to provide a hydrophilic coating liquid for forming a coating film capable of making and maintaining the surface of a member to a high degree of hydrophilicity,
It is an object of the present invention to provide a hydrophilic coating liquid which has excellent dispersion stability as a coating material and is particularly suitable for coating a film on a film and coating a metal material such as an automobile body. Another object of the present invention is to form a coating film capable of preventing clouding and water droplet formation of the member by making the surface of a mirror, glass, lens, prism or other transparent member highly hydrophilic. A hydrophilic coating liquid which has excellent dispersion stability as a coating material and is particularly suitable for coating on a film.
To provide a liquid for sizing. Another object of the present invention is to make a surface of a building, a window glass, a mechanical device or an article highly hydrophilic, thereby preventing the surface from being soiled or allowing the surface to be cleaned using water. A hydrophilic coating liquid for forming a coating film, which has excellent dispersion stability as a coating material, and is particularly suitable for a coating film on a film and a coating film on a metal material such as an automobile body. It is to provide a coating liquid.

[0005]

SUMMARY OF THE INVENTION The present invention is based on the discovery that, in a member having a surface layer containing a photocatalyst formed thereon, when the photocatalyst is photoexcited, the surface of the member is highly hydrophilized. This phenomenon is considered to proceed by the following mechanism. That is, when light having energy equal to or more than the energy gap between the upper end of the valence band and the lower end of the conduction band of the photocatalyst is irradiated on the photocatalyst, the electrons in the valence band of the photocatalyst are excited, and the conduction electrons and holes are generated. Produced and either or both actions impart polarity to the surface. As a result, water is chemically adsorbed on the surface, and a physically adsorbed water layer is formed thereon to increase. As a result, the surface exhibits a high degree of hydrophilicity with a water wetting angle of 10 ° or less.

Further, if the surface layer contains amorphous silica in addition to the photocatalyst, the surface will exhibit hydrophilicity close to a water wetting angle of 0 °, and the hydrophilicity retention when kept in a dark place will be improved. I do.

[0007] In the present invention, the average composition formula Six _P O
_{(4-p) / 2} (where X is an alkoxy group or a halogen atom, and p is a number satisfying 0 <p ≦ 4), a precursor of amorphous silica to form a cause and the amorphous silica coated; formula R _p
SiX _4-p (where R is one or two monovalent organic groups)
Or a functional group composed of at least two kinds selected from a monovalent organic group and a hydrogen group, X is an alkoxy group or a halogen atom, and p is 1 or 2. A hydrolyzable silane derivative represented, or an average composition formula R _p SiX _q O _{(4-pq) / 2} (where R is a functional group comprising one or more monovalent organic groups, or X is a functional group comprising two or more selected from a monovalent organic group and a hydrogen group, and X is an alkoxy group or a halogen atom;
And q are numbers satisfying 0 <p <2, 0 <q <4)
In represented by siloxane oligomer -, or the general formula SiX ₄
(Wherein X is an alkoxy group or a halogen atom), or a tetrafunctional hydrolyzable silane derivative represented by the formula: SiX _q O _{(4-q) / 2} (where X is an alkoxy group ,
Or a halogen atom, q is 0 <silicate represented by the number a is) that satisfies q <4 - Toorigoma - a a surface coated with a photocatalytic oxidation of titanium particles, wherein the film former Containing photocatalytic titanium oxide particles for hydrophilizing the surface of the coating in response to photoexcitation.
The present invention provides a photocatalytic hydrophilic coating liquid of H3-9.
When a coating film is formed on the surface of a substrate with such a coating composition, a curing reaction of the precursor of amorphous silica forms a surface layer containing photocatalytic oxide particles and amorphous silica on the surface of the substrate. Become so. In this case, the physical adsorption water layer is formed in response to the photoexcitation of the photocatalyst, so that the surface exhibits hydrophilicity close to the water wetting angle of 0 °, and the hydrophilicity retention when held in a dark place is improved. I do. In the present invention, the photocatalytic titanium oxide particles may have a surface previously coated with the hydrolyzable silane derivative, the siloxane oligomer, or the tetrafunctional hydrolyzable silane derivative, or the silicate oligomer. As a result, the photocatalytic titanium oxide particles can exhibit excellent dispersion stability even in a neutral liquid. By the way, the precursor component of amorphous silica shown in (a) of claims 1 to 4 has the best dispersion stability in a neutral liquid, and thus the photocatalytic hydrophilic coating is provided by the coating. The composition exhibits good storage stability by being neutralized. The reason is considered as follows.
That is, in the case of only the photocatalytic titanium oxide particles, the isoelectric point is around 7, and under neutral conditions, the isoelectric point on the particle surface becomes almost zero and the particles are easily aggregated. It is considered that by coating with the above-mentioned substance, the isoelectric point of the particle surface shifts to the acidic side, and excellent dispersion stability can be exhibited under neutral conditions of pH 3 to 9. Further, since the coating liquid is neutral and not acidic having a pH of 3 or less, it does not deteriorate the base material even when coated on a metal base which is vulnerable to acid.
Therefore, even when a coating is applied to an automobile body or the like, there is no possibility that the automobile body itself will be adversely affected. Further, for example, in the case of coating on a film, many of the film coating equipment are made of a metal substrate such as a coating machine, a roll, a duct, etc., but there is no risk of adversely affecting the equipment. It is preferred. In addition, the coating solution is neutral,
Since it is not more than 9 basic, the precursor of amorphous silica hardly aggregates.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, photocatalytic titanium oxide refers to light (excitation light) having an energy (ie, a short wavelength) larger than the energy gap between the conduction band and the valence band of the crystal. Irradiates a titanium oxide capable of generating conduction electrons and holes by excitation of electrons in the valence band (photoexcitation) upon irradiation with, for example, an anatase type titanium oxide and a rutile type titanium oxide. Crystalline titanium oxide can be suitably used. The high hydrophilicity in the present invention means a state exhibiting water wettability of 10 ° or less, preferably 5 ° or less in terms of a contact angle with water.

The precursor of the amorphous silica described in (a) of claims 1 to 4 has an average composition formula of SiX _p O _{(4-p) / 2} (where X is an alkoxy group or a halogen atom) Where p is a number satisfying 0 <p ≦ 4)
It is a functional silane derivative or silicate. Here, as the tetrafunctional hydrolyzable silane derivative, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane and the like can be suitably used. Examples of the silicate include alkyl silicates that can be prepared by partial hydrolysis, dehydration condensation polymerization, and the like of the above-mentioned tetrafunctional hydrolyzable silane derivative.
Water glass or the like can be suitably used.

[0010] hydrolyzable silane derivative coating the photocatalytic acid <br/> of titanium down particles that will be described in (b) of claim 1 of the general formula R _p SiX _4-p (wherein, R one X is a functional group composed of one or more of a valence organic group or a functional group composed of two or more selected from a monovalent organic group and a hydrogen group, and X is an alkoxy group or a halogen atom. And p is 1 or 2).

Here, the hydrolyzable silane derivatives include methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, and ethyltripropoxysilane. Tributoxy silane, phenyl trimethoxy silane, phenyl triethoxy silane, phenyl tripropoxy silane, phenyl tributoxy silane, dimethyl dimethoxy silane, dimethyl diethoxy silane, dimethyl dipropoxy silane, dimethyl dibutoxy silane, diethyl dimethoxy silane, diethyl diethoxy Silane, diethyldipropoxysilane, diethyldibutoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, Ludipropoxysilane, phenylmethyldibutoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltripropoxysilane, n-propyltributoxysilane, γ-glycoxydoxypropyltrimethoxysilane, γ- Acryloxypropyltrimethoxysilane and the like can be suitably used.

[0012] Claim 2 of (b) in the described Ru photocatalytic acid <br/> of titanium down particles covering the siloxane oligomer - the average composition formula _{R p SiX q O (4-} pq) / 2 ( wherein Wherein R is a functional group composed of one or more monovalent organic groups, or a functional group composed of two or more monovalent organic groups and a hydrogen group; X is an alkoxy group; Or a halogen atom, and p and q are 0 <p <2, 0 <
q <4 which satisfies q <4), wherein the hydrolyzable silane derivative is partially hydrolyzed and dehydrated and polycondensed, or the hydrolyzable silane derivative is partially hydrolyzed, It refers to a dimer to dimer of a hydrolyzable silane derivative that can be produced by dehydration condensation polymerization with a partial hydrolyzate such as methoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, diethoxydimethoxysilane, and the like. .

[0013] tetrafunctional hydrolyzable silane derivatives covering the photocatalytic acid <br/> of titanium down particles that will be described in (b) of claim 3, the general formula SiX ₄ (wherein, X is an alkoxy group, Or
Which is a halogen atom).

Here, the tetrafunctional hydrolyzable silane derivative includes tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane,
Diethoxydimethoxysilane and the like can be suitably used.

The silicate coating the claims 4 (b) photocatalytic acid <br/> of titanium down particles that will be described - Toorigoma - the average composition formula _{SiX q O (4-q)} / 2 ( wherein , X is an alkoxy group or a halogen atom, and q is a silicate oligomer represented by the following formula: 0 <q <4), and partially hydrolyzes the above tetrafunctional hydrolyzable silane derivative. And dimer to tetramer of a tetrafunctional hydrolyzable silane that can be produced by dehydration-condensation polymerization or the like. Here, as a precursor of the silicone, an average composition formula R
_p SiX _q O _{(4-pq) / 2} (wherein, R is a functional group consisting of one or more monovalent organic groups, or two kinds selected from a monovalent organic group and a hydrogen group. X is an alkoxy group or a halogen atom, and p and q are 0 <p <2, 0 <
a film-forming element made of a siloxane represented by the following formula: q <4, or a general formula R _p SiX _4-p (where R is one or more monovalent organic groups) Wherein X is an alkoxy group or a halogen atom, and p is 1 or 2. A film-forming element comprising a hydrolyzable silane derivative to be
Can be suitably used.

The method of fixing the coating to the photocatalytic oxidation of titanium particles, for example, spray - co - plating method, a dip - coating method, flow - co - plating method, a spin -
After coating by a coating method, a roll coating method, brush coating, sponge coating or the like, it is fixed by a method such as heat treatment.

The coating composition includes Ag, Cu, Z
A metal such as n can be added. When the metal is added, the surface layer formed by the coating film can kill bacteria and fungi attached to the surface even in a dark place.

The coating composition includes Pt, Pd, R
A platinum group metal such as u, Rh, Ir, Os can be added. When the metal is added, the surface layer formed by the coating film can enhance the oxidation-reduction activity of the photocatalyst, and can improve the decomposability of organic stains and the decomposability of harmful gases and odors.

The coating composition may further contain a solvent such as water, ethanol or propanol, hydrochloric acid, nitric acid, sulfuric acid, or the like.
Catalysts that promote hydrolysis of silicone precursors such as acetic acid and maleic acid, basic compounds such as tributylamine and hexylamine, and acidic compounds such as aluminum triisopropoxide and tetraisopropyl titanate For example, a catalyst for curing the precursor of the silicone such as silane coupling agent or a surfactant for improving the dispersibility of the coating liquid such as a silane coupling agent may be added.

The method of using the coating composition of the present invention is basically based on applying the coating composition on the surface of a substrate and curing the coating composition to form a coating film.

The coating method of the above coating composition includes spray coating, dip coating, flow coating, spin coating, roll coating, brush coating, and sponge. A method such as coating can be suitably used. As a curing method, it is possible to carry out polymerization by heat treatment, standing at room temperature, irradiation of ultraviolet rays, or the like.

When a coating film is formed on the member surface by the above method,
The surface of the member becomes hydrophilic in response to the photoexcitation of the photocatalyst. Here, in order for the substrate surface to be highly hydrophilized by photoexcitation of the photocatalyst, the illuminance of the excitation light must be 0.001.
mW suffices / cm ² or more, but preferably that it 0.01 mW / cm ² or more, and more preferably it 0.1 mW / cm ² or more. Light sources used for photoexcitation of the photocatalyst include sunlight,
Interior lighting, fluorescent lamp, mercury lamp, incandescent lamp, xenon lamp, high-pressure sodium lamp, metal halide lamp, B
An LB lamp or the like can be suitably used.

The thickness of the surface layer formed by a coating film on the member surface is preferably 0.4 μm or less. Then, cloudiness due to irregular reflection of light can be prevented, and the surface layer becomes substantially transparent. Furthermore, the thickness of the surface layer is
It is more preferable that the thickness be 0.2 μm or less. Then, it is possible to prevent the surface layer from being colored by light interference. Also, the thinner the surface layer, the better its transparency.
Further, when the film thickness is reduced, the wear resistance of the surface layer is improved.

As shown in PCT / JP96 / 00733, if the surface of the member is not more than 10 ° in terms of the contact angle with water, even if moisture or steam in the air is condensed, it will not condense. Water tends to form a uniform water film without forming individual water droplets. Therefore, the tendency that light scattering fogging does not occur on the surface becomes remarkable. Similarly, when a window glass, a vehicle back mirror, a vehicle windshield, an eyeglass lens, or a shield of a helmet is subjected to rainfall or splashing, discrete unsightly water droplets are not formed, and high visibility and visibility are achieved. As a result, the effects of ensuring safety, ensuring the safety of vehicles and traffic, and improving the efficiency of various tasks and activities are greatly improved. Similarly, as shown in PCT / JP96 / 00733, if the surface of the member is less than or equal to 10 °, preferably less than or equal to 5 ° in terms of the contact angle with water, exhaust from city dust, automobiles, etc. Combustion products such as carbon black contained in gas, hydrophobic contaminants such as oils and fats, sealant eluting components, etc., and inorganic clay contaminants are unlikely to adhere, and even if adhered, it is easy to rain and wash. Can be dropped.

When the surface of the member exhibits the above-mentioned high hydrophilicity and maintains the state, the anti-fogging effect, the surface cleaning effect, the drying promotion effect of the attached water droplets, the antistatic effect, the dust adhesion The effect of prevention, the effect of heat insulation, the effect of preventing air bubbles from adhering to water, the effect of improving efficiency in a heat exchanger, the effect of improving biocompatibility, and the like are exhibited.

The substrate to which the present invention can be applied is a transparent member when an anti-fogging effect is expected, and glass, plastic, and the like can be suitably used as the material. Speaking of applicable base materials, mirrors such as rearview mirrors for vehicles, bathroom mirrors, toilet mirrors, dental mirrors, road mirrors; spectacle lenses, optical lenses, illumination lenses, semiconductor lenses Lenses for copiers, copier lenses, rear view camera lenses for vehicles; prisms; windows of buildings and towers; automobiles, railway vehicles, aircraft, ships, submersibles, snowmobiles, lowway gondola, amusement parks Gondolas, vehicle windows such as spaceships; cars, motorbikes, railway vehicles, aircraft, ships, submersibles, snowmobiles, snowmobiles, lowway gondola, amusement park gondola, space Windshield for vehicles such as ships; protective goggles, sports goggles, protective mask shield, sports mask shield, helmet shield, frozen food display Case glass, Chinese bun, etc. Glass for display case of warm food; Cover of measuring instrument, Cover of camera lens for confirming the rear of vehicle, Focusing lens of laser dental treatment device, etc., Laser light detection of inter-vehicle distance sensor, etc. Cover for an infrared sensor; cover for an infrared sensor; a filter for a camera; and a film, sheet, seal, or the like to be attached to the surface of the article.

When a surface cleaning effect is expected as a substrate to which the present invention can be applied, the material may be, for example, metal, ceramic, glass, plastic, wood, stone, cement, concrete, fiber, Fabrics, combinations thereof, and laminates thereof can be suitably used. Speaking of applicable base materials, building materials, building exteriors, building interiors, window frames, windowpanes, structural members, vehicle exteriors and coatings, machinery and articles exteriors, dustproof covers and coatings, traffic signs, Various display devices,
Advertising towers, noise barriers for roads, noise barriers for railways, bridges, exterior and coating of garages, tunnel interiors and coatings, insulators, solar battery covers, solar water heater collector covers, vinyl houses, vehicle lighting Light covers, housing equipment, toilets, bathtubs, wash basins, lighting fixtures, lighting covers, kitchen utensils, dishes, dishwashers, dish dryers, sinks, cooking ranges, kitchen hoods
And a film, a sheet, a seal, and the like for attaching to the surface of the article.

As a substrate to which the present invention can be applied, when an effect of promoting drying of attached water droplets is expected, the material is, for example, metal, ceramic, glass, plastic, wood, or the like.
Stones, cements, concretes, fibers, fabrics, combinations thereof, and laminates thereof can be suitably used. Examples of the applicable substrate include a car body, a window, a pavement, and a film, a sheet, a seal, and the like for attaching to the surface of the article.

As a substrate to which the present invention can be applied, when an antistatic effect is expected, its material is, for example, metal,
Ceramic, glass, plastic, wood, stone, cement, concrete, fiber, fabric, combinations thereof, and laminates thereof can be suitably used. Speaking of applicable substrates, cathode ray tubes, magnetic recording media, optical recording media, magneto-optical recording media, audio tapes, video tapes, analog records, housings and parts for household electrical appliances, Exterior and coating, OA equipment product housing and parts and exterior and painting, building materials, building exterior, building interior, window frames, window glass, structural members, vehicle exterior and painting, machinery and articles exterior, dustproof cover and Includes films, sheets, seals, etc. for painting and sticking to the surface of the article.

[0030]

EXAMPLES After surface treatment with the photocatalytic oxidation of titanium particles produced by a chloride process γ- glycoxide trimethoxysilane was dispersed in water pH 7. After mixing this dispersion and a methyl silicate resin coating, the mixture was diluted with ethanol and stirred for 3 hours to obtain a coating liquid. This coating liquid was left at 17 ° C. for one month, but the dispersibility was good. When the coating liquid was applied to a quartz glass plate and cured at 150 ° C., the sample was irradiated with a BLB lamp having an ultraviolet illuminance of 0.5 mW / cm ² for 3 days.
The contact angle with water became 0 °.

[0031]

The photocatalytic hydrophilic coating liquid of the present invention has excellent long-term storage stability and can maintain and maintain the surface of the member to a high degree of hydrophilicity.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 183/02 C09D 1/00 C09D 5/00 C09C 1/36

Claims (8)

(57) [Claims] 1. An amorphous silica film is formed when cured.
A film-forming element to be dispersed in the film-forming element;
Light contact for hydrophilizing the surface of the coating in response to light excitation
PH 3-9 photocatalyst containing medium titanium oxide
A hydrophilic coating liquid, wherein the film-forming element has an average composition formula of Si x _P O _{(4-p) / 2} (where X is an alkoxy group or a halogen atom,
Is a number that satisfies 0 <p ≦ 4).
The photocatalytic titanium oxide is a hydrolyzable silane derivative.
The hydrolyzable silane derivative coated on the surface has a general formula R _p SiX _4-p (the above formula is methyltrimethoxysilane, methyltrimethoxysilane)
Ethoxysilane, methyltripropoxysilane, methyl
Tributoxysilane, ethyltrimethoxysilane, ethyl
Rutriethoxysilane, ethyltripropoxysilane,
Ethyl tributoxy silane, phenyl trimethoxy sila
Phenyltriethoxysilane, phenyltripropo
Xysilane, phenyltributoxysilane, dimethyldi
Methoxysilane, dimethyldiethoxysilane, dimethyl
Dipropoxy silane, dimethyl dibutoxy silane, die
Tildimethoxysilane, diethyldiethoxysilane, di
Ethyldipropoxysilane, diethyldibutoxysila
Phenylmethyldimethoxysilane, phenylmethyl
Diethoxysilane, phenylmethyldipropoxysila
, Phenylmethyldibutoxysilane, n-propyl
Limethoxysilane, n-propyltriethoxysilane,
n-propyltripropoxysilane, n-propyltri
Butoxysilane, γ-glycoxydoxypropyl trime
Toxysilane, γ-acryloxypropyltrimethoxy
Silane). 2. A film of amorphous silica is formed when cured.
A film-forming element to be dispersed in the film-forming element;
Light contact for hydrophilizing the surface of the coating in response to light excitation
PH 3-9 photocatalyst containing medium titanium oxide
A hydrophilic coating liquid, wherein the film-forming element has an average composition formula of Si x _P O _{(4-p) / 2} (where X is an alkoxy group or a halogen atom,
Is a number that satisfies 0 <p ≦ 4).
The photocatalytic titanium oxide is represented by a siloxane oligomer.
And the siloxane oligomer has an average composition formula of R _p SiX _q O
_{(4-pq) / 2} (wherein R represents one or more monovalent organic groups)
Functional group, or selected from monovalent organic groups and hydrogen groups
X is an alkoxy group,
Is a halogen atom, p and q are 0 <p <2, 0 <
is a number that satisfies q <4 and has the hydrolysis defined below.
Partial hydrolysis and dehydration polycondensation of reactive silane derivatives, or
Partial hydrolysis of hydrolyzable silane derivatives defined below
Thing, tetramethoxysilane, tetraethoxysilane,
Tetrapropoxysilane, tetrabutoxysilane, die
Dehydration with partial hydrolyzate such as toxicdimethoxysilane
Of hydrolyzable silane derivatives that can be made by polymerization
It refers to dimer to dimer where the hydrolyzable silane derivative is represented by the general formula R _p SiX
_4-p (The above formula is methyltrimethoxysilane, methyltrimethoxysilane
Ethoxysilane, methyltripropoxysilane, methyl
Tributoxysilane, ethyltrimethoxysilane, ethyl
Rutriethoxysilane, ethyltripropoxysilane,
Ethyl tributoxy silane, phenyl trimethoxy sila
Phenyltriethoxysilane, phenyltripropo
Xysilane, phenyltributoxysilane, dimethyldi
Methoxysilane, dimethyldiethoxysilane, dimethyl
Dipropoxy silane, dimethyl dibutoxy silane, die
Tildimethoxysilane, diethyldiethoxysilane, di
Ethyldipropoxysilane, diethyldibutoxysila
Phenylmethyldimethoxysilane, phenylmethyl
Diethoxysilane, phenylmethyldipropoxysila
, Phenylmethyldibutoxysilane, n-propyl
Limethoxysilane, n-propyltriethoxysilane,
n-propyltripropoxysilane, n-propyltri
Butoxysilane, γ-glycoxydoxypropyl trime
Toxysilane, γ-acryloxypropyltrimethoxy
Silane). 3. An amorphous silica film is formed when cured.
And film formers which are dispersed in the coating film forming components in this,
Light contact for hydrophilizing the surface of the coating in response to light excitation
PH 3-9 photocatalyst containing medium titanium oxide
A hydrophilic coating liquid, wherein the film-forming element has an average composition formula of Si x _P O _{(4-p) / 2} (where X is an alkoxy group or a halogen atom,
Is a number that satisfies 0 <p ≦ 4).
In addition, the photocatalytic titanium oxide is capable of inducing tetrafunctional hydrolyzable silane.
The surface is coated with a conductor, and the tetrafunctional hydrolyzable silane derivative has the general formula Si
X ₄ , wherein X is an alkoxy group or a halogen atom
). 4. A film of amorphous silica is formed when cured.
A film-forming element to be dispersed in the film-forming element;
Light contact for hydrophilizing the surface of the coating in response to light excitation
PH 3-9 photocatalyst containing medium titanium oxide
A hydrophilic coating liquid, wherein the film-forming element has an average composition formula of Si x _P O _{(4-p) / 2} (where X is an alkoxy group or a halogen atom,
Is a number that satisfies 0 <p ≦ 4).
The photocatalytic titanium oxide is represented by a silicate oligomer.
Is obtained by coating the surface, the silicate oligomer, the average composition formula SiX _q O
_{(4-q) / 2} (where X is an alkoxy group or a halogen atom, q
Is a number that satisfies 0 <q ≦ 4).
You. 5. The coating, the surface of which has been hydrophilized in response to photoexcitation, allowing the condensed water and / or water droplets of moisture adhering to the surface to spread on the surface of the coating, whereby the coating The photocatalytic hydrophilic coating liquid according to any one of claims 1 to 4, wherein the substrate coated with the liquid is prevented from being clouded or shaded by condensed water and / or water droplets of moisture. . 6. The coating, the surface of which has been hydrophilized in response to photo-excitation, allows for deposits and / or contaminants to be washed away by rainwater when exposed to rainfall, whereby the surface self The photocatalytic hydrophilic coating liquid according to any one of claims 1 to 4, which enables purification. 7. The coating whose surface has been hydrophilized in response to photoexcitation prevents contamination from adhering to the surface when rainwater containing the contamination comes into contact. The photocatalytic hydrophilic coating liquid according to any one of claims 4 to 4 . 8. The coating, the surface of which has been hydrophilized in response to photoexcitation, releases adhering deposits and / or contaminants when immersed in or wetted with water, thereby causing the surface to become hydrated. 3. The method according to claim 1, wherein the cleaning is facilitated.
5. The photocatalytic hydrophilic coating liquid according to any one of 4 .