JP2024026264A - Window glass for vehicle - Google Patents

Abstract

To provide a window glass for a vehicle, free from inappropriate dot-like fixing components as a visible light transmission region, and having a visible light transmittance adjusted to a preferable value, and an improved appearance quality, and formed with a multicolor coating film.SOLUTION: A window glass 1 for a vehicle includes a bent glass plate 2 having a principal plane, and includes on the principal plane, a first coated part 31 comprising a first colored coating film, and a second coated part 32 adjacent to the first coated part and comprising a second colored coating film or a colorless coating film having a visible light transmittance higher than that of the first colored coating film. The coating films of the first coated part and the second coated part are coating films integrated with uniform film thickness, formed by applying and drying a first coating liquid for forming the first coated part and a second coating liquid for forming the second coated part, and there is provided between the first coated part and the second coated part, a boundary part 33 which is formed by mixing the first coating liquid and the second coating liquid, and in which a visible light transmittance is gradually changed from the first coated part to the second coated part.SELECTED DRAWING: None

Description

The present disclosure relates to a vehicle window glass on which a colored film is formed, and a method for manufacturing the same.

In recent years, as the functions of vehicles have become more sophisticated, vehicles have come to be equipped with various devices such as sensors, communication devices, on-vehicle cameras, high-mounted stop lamps, and video display devices. Therefore, vehicle window glasses are required to utilize the functions of various devices or not to impair them. On the other hand, from the viewpoints of design, privacy protection, heat shielding properties, etc., there is also a demand for vehicle window glasses on which a colored film with low visible light transmittance is formed. As described above, the compatibility between the functions of various devices and the functions of colored coatings is also being questioned.

From this point of view, Patent Documents 1 and 2 disclose that in a vehicle window glass with a dark-colored coating, a region where a high-mounted stop lamp is disposed is a region without the dark-colored coating. In particular, Patent Document 1 discloses that a dark-colored film is not formed on the emitted light transmitting portion, or it is removed after the dark-colored film is formed, or a film that has higher visible light transmittance than the dark-colored film is formed, etc. discloses that the visible light transmittance of the emitted light transmitting portion is higher than that of the dark colored portion. Further, Patent Document 2 discloses a method in which a dark-colored film is formed on the entire surface of the glass by a spray method or the like, and then the part is removed by sandblasting to form the part with high visible light transmittance.

Japanese Patent Application Publication No. 6-40252 Japanese Patent Application Publication No. 11-157882

In a vehicle window glass on which a colored film is formed, the film has a different color (including colorless) depending on the part of the window glass (hereinafter, in this specification, it may be referred to as a "multicolored film") ) can be a solution to achieving compatibility between the functions of various devices and the functions of the colored film. Various coating methods can be used as a method for forming a multicolored coating, but coating formation by a spraying method is efficient.

However, since the spray method is a coating method that scatters mist onto the substrate, it is possible to prevent the mist from scattering to areas other than the target area and forming droplets of the coating liquid on the main surface of the glass plate. I can't pass. In a vehicle window glass, the components of a coating liquid for forming a film are adjusted so that the film and the glass can be brought into close contact with each other. Therefore, the droplets formed in areas other than the areas to be coated adhere to the surface of the glass plate, resulting in the formation of dot-shaped fixed components on the surface of the glass plate. Since the vehicle window glass on which the colored film is formed is a visible light transparent article, the dot-like fixed components become visible.

Patent Document 1 discloses a method of forming a film having a higher visible light transmittance than a dark-colored film on the emitting light transmitting part, but there is no specific disclosure regarding the spray method, and there is no point-like fixation in the spray method. The problem with the ingredients has not yet been recognized.

In consideration of the above, the present disclosure provides a glass plate on which a colored film is formed, the part of the glass plate having a coating having higher visible light transmittance than the colored film formed on some parts by a spray method. A vehicle window glass is made of a coating liquid of a colored film and is free of dot-like fixed components, and the colored film and both the parts are integrally formed by a spraying method to reduce optical distortion and appearance quality. The challenge is to provide means for improvement.

The vehicle window glass of the present disclosure includes:
a curved glass plate having a main surface;
On the main surface, a first coating portion consisting of a first colored coating, and a second coating portion adjacent to the first coating portion and consisting of a second colored coating or a colorless coating having a higher visible light transmittance than the first colored coating. A vehicle window glass comprising two coating parts,
The coatings of the first coating portion and the second coating portion are formed by applying and drying a first coating liquid for forming the first coating portion and a second coating liquid for forming the second coating portion. In addition, it is an integrated coating with a uniform thickness,
Between the first coating part and the second coating part, visible light transmittance is formed from the first coating part to the second coating part formed by mixing the first coating liquid and the second coating liquid. has a boundary where the value gradually changes.

By making the structure of the vehicle window glass having the multicolored film into the above structure, the dot-like fixed components are difficult to be visually recognized. Further, by integrating the first coating portion and the second coating portion with a uniform thickness, optical distortion at the boundary portion can be reduced. Furthermore, the visible light transmittance of the boundary between the first coating part and the second coating part gradually changes from the first coating part to the second coating part, thereby making the boundary part conspicuous. This improves the appearance quality of the multicolored film.

In the second coating portion, the second colored coating having a higher visible light transmittance than the first colored coating is based on the visible light transmittance required for high-mount stop lamps and various on-vehicle cameras. The visible light transmittance of the second colored coating may be 5% or more, preferably 20% or more higher than that of the first colored coating. It is preferable that both the first colored film and the second colored film contain the same pigment, and the coloring of the film is caused by the pigment. Furthermore, a colorless coating is one in which the color tone of the glass plate changes little due to the coating, and the absorbance of the colorless coating per 1 μm of thickness is 0.20 or less in the wavelength range of 380 nm to 780 nm. , preferably 0.10 or less, is defined as a colorless film. In addition, the absorbance can be calculated from the following formula.

Absorbance = Log ₁₀ (I ₀ /I) = a×L
I ₀ = intensity of incident light
I = intensity of transmitted light
a = absorbance per 1 μm thickness
L = optical path length

<First manufacturing method>
The method for manufacturing a vehicle window glass of the present disclosure (first manufacturing method) includes:
a curved glass plate having a principal surface; a first coating portion comprising a first colored coating on the principal surface; adjacent to the first coating portion and having a higher visible light transmittance than the first colored coating; A method for manufacturing a vehicle window glass comprising a second coating portion consisting of a second colored coating or a colorless coating,
a step (1) of preparing a first coating liquid for forming the first coating part and a second coating liquid for forming the second coating part;
a step (2a) of preparing a liquid film of the first coating liquid by spraying a mist of the first coating liquid onto a location where the first coating portion is to be formed, using a spray method;
a step (2b) of preparing a liquid film of the second coating liquid by spraying a mist of the second coating liquid onto a location where the second coating portion is to be formed;
a step (3) of drying and curing each liquid film,
In the step (2b), before the droplets of the first coating liquid formed in the area where the second coating portion is to be formed by the mist of the first coating liquid in the step (2a) dry, spraying a mist of a second coating liquid to form a boundary portion consisting of a mixed liquid film of the first coating liquid film and the second coating liquid film, and forming a liquid film of the second coating liquid; Prepare.

<Second manufacturing method>
The method for manufacturing a vehicle window glass of the present disclosure (second manufacturing method) includes:
a curved glass plate having a principal surface; a first coating portion comprising a first colored coating on the principal surface; adjacent to the first coating portion and having a higher visible light transmittance than the first colored coating; A method for manufacturing a vehicle window glass comprising a second coating portion consisting of a second colored coating or a colorless coating,
a step (1) of preparing a first coating liquid for forming the first coating part and a second coating liquid for forming the second coating part;
a step (2c) of preparing a liquid film of the second coating liquid by spraying a mist of the second coating liquid onto a location where the second coating portion is to be formed;
a step (2d) of preparing a liquid film of the first coating liquid by spraying a mist of the first coating liquid onto a location where the first coating portion is to be formed;
a step (3) of drying and curing each liquid film,
In the step (2d), before the droplets of the second coating liquid formed at the formation site of the first coating part by the mist of the second coating liquid in the step (2c) dry, spraying a mist of the first coating liquid to form a boundary portion consisting of a mixed liquid film of the second coating liquid film and the first coating liquid film, and forming a liquid film of the first coating liquid; Prepare.

In the first manufacturing method and the second manufacturing method, the coating liquid is applied to the glass plate by a spray method. The spray method is a method suitable for applying a coating liquid to the entire main surface of a glass plate with high efficiency. However, the mist scattered during the application of the coating liquid will be applied to areas other than the target area, so when forming a multi-colored film, it is necessary to avoid the sticking components caused by the mist scattered to areas where other colored films should be formed. The important thing is how to solve it. In the first manufacturing method and the second manufacturing method, before the fixed component caused by the mist scattered on the location where the other color coating is to be formed dries, the coating is applied to form the other color coating on the location. By applying the liquid, the fixed components caused by the mist and the coating liquid are mixed on the glass plate to eliminate the fixed components, and as a result, the coatings of other colors are made homogeneous in appearance.

According to the present disclosure, even when using a spray method, a multicolored film is formed that has no dot-like fixed components that are inappropriate for the visible light transmittance region, has visible light transmittance adjusted to a preferable value, and has improved appearance quality. A vehicle window glass is provided. Further, the first coating portion and the second coating portion form an integrated coating with a uniform thickness, and the visible light transmittance gradually changes from the first coating portion to the second coating portion. Forming the boundary reduces optical distortion, makes the boundary less noticeable, and improves the appearance quality of the multicolored coating.

FIG. 1 is a schematic front view of an example of a vehicle window glass according to the present disclosure, viewed from the outside of the vehicle. 2 is a diagram schematically showing a cross-sectional shape taken along a-a' line shown in FIG. 1. FIG. FIG. 2 is a schematic front view of a vehicle window glass in a different form from that shown in FIG. 1. FIG. FIG. 1 is a diagram schematically illustrating a first method for manufacturing a vehicle window glass according to the present disclosure. FIG. 3 is a diagram schematically illustrating a state when a second coating liquid is applied by a spray method after forming a liquid film of the first coating liquid on a glass plate in the first manufacturing method. It is a figure explaining typically the second manufacturing method of the vehicle window glass of this indication. FIG. 6 is a diagram schematically illustrating a state when a first coating liquid is applied by a spray method after forming a liquid film of the second coating liquid on a glass plate in the second manufacturing method. FIG. 2 is a schematic front view of a derivative of the vehicle window glass shown in FIG. 1; 9 is a diagram schematically showing a cross-sectional shape taken along a-a' line shown in FIG. 8. FIG.

Hereinafter, the present disclosure will be explained using the drawings. FIG. 1 is a schematic front view of an example of a vehicle window glass according to the present disclosure, viewed from the outside of the vehicle, and FIG. 2 is a diagram schematically showing a cross-sectional shape taken along a-a' line shown in FIG. 1. In this example, the first coating portion 31 and the second coating portion 32 are formed on the concave main surface 21 of the glass plate 2, but may be formed on the convex main surface 22.

The vehicle window glass 1 shown in FIGS. 1 and 2 includes a curved glass plate 2 having a concave main surface 21 and a convex main surface 22, and a first colored coating formed on the concave main surface 21. A second coating portion 31 is provided, and a second coating portion 32 is made of a second colored coating or a colorless coating that has a higher visible light transmittance than the first colored coating. The first coating portion 31 and the second coating portion 32 form an integrated coating with a uniform thickness. The vehicle window glass 1 has a boundary between the first coating portion 31 and the second coating portion 32 where the visible light transmittance gradually changes from the first coating portion 31 to the second coating portion 32. It has a section 33. The vehicle window glass 1 has the first coating portion 31 and the second coating portion 32, that is, it has a multicolored coating.

As the glass plate 2, a glass plate having a shape suitable for a window of a vehicle such as an automobile is used, and usually a trapezoidal shape, a rectangular shape, etc. can be used. As the glass plate 2, a plate glass manufactured by a float method or the like, which is commonly used for vehicles such as automobiles, can be used. The end surface of the glass plate 2 may be processed into an R shape by polishing.

The thickness of the glass plate 2 is not particularly limited, but the main surfaces 21 and 22 of the glass are parallel, and for example, the thickness is 0.3 to 15 mm, or the thickness is 0.5 to 5 mm. , a thickness of 1 to 3 mm can be used. Further, the glass plate 2 preferably has an absorbance of 0.10 or less, preferably 0.02 or less per 1 mm of thickness in the wavelength range of 380 nm to 780 nm. This type of glass plate is a glass plate that appears almost colorless when observed from the main surfaces 21 and 22, and the color of the first coating portion 31 itself can be reflected on the vehicle window glass 1.

Further, the glass plate 2 may include a visible light shielding layer 4. The visible light shielding layer 4 is formed on the peripheral edge of the glass plate 2, and its thickness may be, for example, 8 μm to 20 μm. The first coating portion 31 may be formed on the visible light shielding layer 4 . The visible light shielding layer 4 is, for example, a band-shaped decorative body made of a black ceramic shielding film, and can be formed of a general-purpose material. For example, a ceramic paste is applied by screen printing on the main surface of the glass plate 2, preferably on the concave main surface 21, and through a drying process and a firing process, the visible light shielding layer 4 made of a color ceramic such as black ceramic is formed. It is formed. When the glass plate 2 includes a visible light shielding layer 4 directly above the main surface, preferably directly above the concave main surface 21, the visible light blocking layer 4 is provided between the first coating portion 31 and the main surface, preferably the first coating. It is preferable that it is between the portion 31 and the concave main surface 21.

It is desirable that the main surface of the glass plate 2 be cleaned and dried before the first coating portion 31, the second coating portion 32, and the boundary portion 33 are formed. For example, as an example of cleaning, known cleaning methods such as cleaning using an abrasive such as cerium oxide, brush cleaning, showering, and high-pressure showering can be used. Further, for the drying, known drying methods such as natural drying and air shower can be used. Alternatively, dry cleaning using atmospheric pressure plasma or UV ozone may be used.

As shown in FIG. 2, the first coating portion 31 and the second coating portion 32 are adjacent to each other with a boundary portion 33 interposed therebetween, and the first coating portion 31 and the second coating portion 32 are adjacent to each other via a boundary portion 33. A completed coating is formed in which the portion 33 is integrated with a uniform thickness. A boundary portion 33 is formed between the first coating portion 31 and the second coating portion 32, and the visible light transmittance gradually changes from the first coating portion 31 to the second coating portion 32. At the boundary portion 33, the concentration of the coloring component of the first colored coating forming the first coating portion 31 is diluted by the second coating liquid, so that it gradually becomes thinner toward the second coating portion 32. Since the second coating portion 32 is made of a second colored coating or a colorless coating that has a higher visible light transmittance than the first colored coating forming the first coating portion, at the boundary portion 33, the first coating portion 31 The visible light transmittance gradually changes from the second coating portion 32 to the second coating portion 32.

As shown in FIG. 2, since a complete film is formed that is integrated with a uniform thickness, from the first film part 31 to the second film part 32, there is less discomfort to the human eye. A multicolored film with good appearance quality can be obtained. In the finished film integrated with a uniform thickness, the thickness is preferably 1.5 μm to 8 μm. If the thickness is less than 1.5 μm, the color development of the film will deteriorate, so it is necessary to increase the pigment content to maintain the color development, and as a result, the durability of the film tends to be poor. It tends to get worse. Taking these into consideration, the thickness of the completed coating may be more preferably 2 μm to 7 μm, and even more preferably 2.5 μm to 6 μm. Further, the width of the boundary portion 33 may be 10 mm to 40 mm from the viewpoint of ease of manufacture and appearance quality.

In each structure of the first coating part 31, the boundary part 33, and the second coating part 32, it is preferable that the base material forming the coating is the same. That is, it is preferable that the difference in each structure is the type and content of the coloring component. With such a configuration, it becomes easy to form a completed coating in which the first coating portion 31, the boundary portion 33, and the second coating portion 32 are integrated with a uniform thickness.

Further, as shown in FIG. 1, the second coating portion 32 may be surrounded by a boundary portion 33, and the boundary portion 33 may be surrounded by the first coating portion 31. In the vehicle window glass 1 having this structure, the second coating part 32, which has a higher visible light transmittance than the first coating part 31, is used for light emission from high-mounted stop lamps, incident light to various sensors, and light from communication equipment. It can be a window for passing emitted light, incident light to an on-vehicle camera, etc.

Further, as a derivative form of the vehicle window glass 1 shown in FIG. 1, as shown in FIG. There are some structures. Inside this protruding structure, there is a visible window that allows light to pass through, such as the light emitted by the high-mounted stop lamp, the incident light to various sensors, the emitted light from communication equipment, and the incident light to the vehicle-mounted camera. A blank portion of the visible light shielding layer 4 in which the light shielding layer 4 is not formed is provided. For example, the second coating portion 32 may be formed in this blank portion, and as shown in FIG. 9, a boundary portion 33 may be provided on the protruding portion of the visible light shielding layer 4. The first coating portion 31 and the second coating portion 32 may also be provided on the site.

Since it is possible to determine whether there is a gradual change in the visible light transmittance of the film at the visual level, the formation of the boundary portion 33 on the visible light shielding layer 4 contributes to the efficiency of quality inspection of vehicle window glass. can do.

Furthermore, the vehicle window glass 1 may have a structure in which a first coating part 31 and a second coating part 32 are divided into upper and lower parts with a boundary part 33 in between, as shown in FIG. Furthermore, the vehicle window glass 1 may have a structure in which the first coating part 31 and the second coating part 32 are divided into left and right parts via a boundary part 33 (not shown).

<Material material of coating>
As mentioned above, it is preferable that the base materials forming the coatings of the first coating portion 31, the second coating portion 32, and the boundary portion 33 are made of the same material. Preferably, the base material is made of a metal alkoxide condensate. Moreover, it is preferable that the first colored coating, the second colored coating, and the colorless coating are formed from a coating liquid containing a metal alkoxide and/or a condensate of a metal alkoxide.

The first coating liquid for forming the first coating portion consisting of the first colored coating includes:
(a) A silane compound containing an amino group represented by R ¹ _4-n Si(OR ² ) _n [1] (in formula [1], R ¹ represents an organic group containing an amino group, and R ² represents a methyl group, ethyl group or propyl group, n represents an integer selected from 1 to 3),
A reaction product obtained by reacting with at least one boron compound selected from the group consisting of H ₃ BO ₃ and B ₂ O ₃ ;
(b) metal alkoxide and/or metal alkoxide condensate;
(f) pigment;
It is possible to use a mixture formed by mixing. In addition to the above (a), (b), and (f),
(c) synthetic resin;
(d) a triazine-based ultraviolet absorber having an SP value of 10 to 13.5 (cal/cm ³ ) ^1/2 ;
(e) a solvent consisting of a nonaqueous solvent having an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 ;
may be added to form the first coating liquid.

Further, the second coating liquid (A) for forming the second coating portion consisting of the second colored coating includes:
(a) A silane compound containing an amino group represented by R ¹ _4-n Si(OR ² ) _n [1] (in formula [1], R ¹ represents an organic group containing an amino group, and R ² represents a methyl group, ethyl group or propyl group, n represents an integer selected from 1 to 3),
A reaction product obtained by reacting with at least one boron compound selected from the group consisting of H ₃ BO ₃ and B ₂ O ₃ ;
(b) metal alkoxide and/or metal alkoxide condensate;
(f) pigment;
It is possible to use a mixture formed by mixing. In addition to the above (a), (b), and (f),
(c) synthetic resin;
(d) a triazine-based ultraviolet absorber having an SP value of 10 to 13.5 (cal/cm ³ ) ^1/2 ;
(e) a solvent consisting of a nonaqueous solvent having an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 ;
may be added to form the second coating liquid (A).

Furthermore, the second coating liquid (B) for forming the second coating portion made of a colorless coating includes:
(a) A silane compound containing an amino group represented by R ¹ _4-n Si(OR ² ) _n [1] (in formula [1], R ¹ represents an organic group containing an amino group, and R ² represents a methyl group, ethyl group or propyl group, n represents an integer selected from 1 to 3),
A reaction product obtained by reacting with at least one boron compound selected from the group consisting of H ₃ BO ₃ and B ₂ O ₃ ;
(b) metal alkoxide and/or metal alkoxide condensate;
It is possible to use a mixture formed by mixing. In addition to the above (a) and (b),
(c) synthetic resin;
(d) a triazine-based ultraviolet absorber having an SP value of 10 to 13.5 (cal/cm ³ ) ^1/2 ;
(e) a solvent consisting of a nonaqueous solvent having an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 ;
may be added to form the second coating liquid (B).

When each of the above-mentioned coating liquids contains the ultraviolet absorber, it is preferable that the ultraviolet absorber is contained in an amount of 5 to 12% by mass based on the total solid content. The above-mentioned "total solid content" refers to the total amount of the components constituting the film, and the amount is calculated from the total amount of components from the coating solution excluding the solvent, and from each component by hydrolysis, polycondensation reaction, etc. It can be determined by reducing the amount of organic groups that are eliminated. The viscosity of the coating solution is also affected by the amount of total solids in the coating solution for film formation, so it can be set in consideration of the coating efficiency of each coating solution on the glass plate. %, preferably 10% to 35% by weight.

Next, each of the above components (a) to (f) will be explained in detail.
<About component (a)>
A silane compound containing an amino group represented by R ¹ _4-n Si(OR ² ) _n [1] (in formula [1], R ¹ represents an organic group containing an amino group, and R ² represents a methyl group) , represents an ethyl group or a propyl group, and n represents an integer selected from 1 to 3),
When mixed with at least one boron compound selected from the group consisting of H ₃ BO ₃ and B ₂ O ₃ , these components react and become a transparent, viscous liquid and solidify in a few minutes to several tens of minutes. This is because the boron compound acts as a crosslinking agent via the amino group in the silane compound containing the amino group, and polymerizes these components. This is thought to be because as a result, the liquid becomes viscous and solidifies. Note that the silane compound containing an amino group is a liquid. It is preferable that water not be used in the reaction between the amino group-containing silane compound and the boron compound.

In the silane compound containing an amino group, R ¹ represents an organic group containing an amino group. For example, monoaminomethyl, diaminomethyl, triaminomethyl, monoaminoethyl, diaminoethyl, triaminoethyl, tetraaminoethyl, monoaminopropyl, diaminopropyl, triaminopropyl, tetraminopropyl, monoaminobutyl, diaminobutyl, Examples include, but are not limited to, triaminobutyl, tetraminobutyl, and organic groups having an alkyl group or aryl group having more carbon atoms than these. γ-aminopropyl (also referred to as 3-aminopropyl) and aminoethylaminopropyl are particularly preferred, and γ-aminopropyl is most preferred.

The R ² represents a methyl group, an ethyl group, or a propyl group. Among these, methyl group and ethyl group are preferred. The n represents an integer selected from 1 to 3. Among these, it is preferable that n is 2 or 3, and it is particularly preferable that n is 3. That is, as the silane compound containing an amino group, γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane are particularly preferred.

The boron compound is at least one boron compound selected from the group consisting of H ₃ BO ₃ and B ₂ O ₃ . Particularly preferred is H ₃ BO ₃ .

Considering the reaction rate, the amount of both components used in the reaction between the amino group-containing silane compound and the boron compound is preferably 0.0. The ratio is from 0.02 mol to 8 mol, more preferably from 0.02 mol to 5 mol, even more preferably from 0.2 mol to 5 mol.

The conditions for mixing the amino group-containing silane compound and the boron compound (temperature, mixing time, mixing method, etc.) can be selected as appropriate. Under normal room temperature conditions, it becomes a transparent, viscous liquid and solidifies in a few minutes to several tens of minutes. The solidification time and the viscosity and rigidity of the resulting reaction product also vary depending on the proportion of the boron compound. Note that a viscous liquid is preferable to a solidified one because it is easier to form a stable dissolved component in the coating liquid. The reaction product is preferably a reaction product obtained by reacting the amino group-containing silane compound with the boron compound without adding water and hydrolyzing it.

The amount of the reaction product may be 40% to 80% by weight based on the total solid content. If the amount is less than 40% by mass, the hardness of the resulting coating may become low. On the other hand, if it exceeds 80% by mass, the resulting coating may develop cracks during the weather resistance test. Considering these, the amount of the reaction product may be 50% by mass to 70% by mass based on the total solid content.

<About component (b)>
A metal alkoxide and/or a metal alkoxide condensate is added as component (b) to the reaction product. That is, component (b) is added during or after the reaction between the amino group-containing silane compound and the boron compound. By adding component (b), the hardness of the resulting film can be improved, and since it becomes a viscous liquid similar to when component (b) is not used, it is stable in the coating solution. It can be made into a dissolved component.

Examples of the metal of the metal alkoxide component (b) include Si, Ta, Nb, Ti, Zr, Al, Ge, B, Na, Ga, Ce, V, Ta, P, and Sb. Not limited to these. Preferred are Si, Ti, and Zr, and since component (b) is preferably a liquid, Si and Ti are particularly preferred. Examples of the alkoxide (alkoxy group) of the metal alkoxide of component (b) include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and an alkoxy group having more carbon atoms. A methoxy group, an ethoxy group, a propoxy group, and a butoxy group are preferred, and a methoxy group and an ethoxy group are more preferred. Particularly preferred component (b) includes tetramethoxysilane and tetraethoxysilane.

Specific examples of the metal alkoxide of component (b) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, propyltripropoxysilane, butyltributoxysilane, and tetramethoxysilane. Methoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, methyltrimethoxytitanium, ethyltriethoxytitanium, propyltripropoxytitanium, butyltributoxytitanium, tetramethoxyzirconium, tetraethoxyzirconium, tetrapropoxyzirconium, tetrabutoxyzirconium , methyltrimethoxyzirconium, ethyltriethoxyzirconium, propyltripropoxyzirconium, and butyltributoxyzirconium. Among them, preferred are tetraethoxysilane, tetramethoxysilane, ethyltriethoxysilane, and methyltrimethoxysilane.

The amount of metal alkoxide used as component (b) is preferably 10 mol or less per mol of the amino group-containing silane compound or 1 mol of the boron compound. More preferably, the ratio is from 0.1 mol to 5 mol. If component (b) is less than 0.1 mol per mol of the silane compound containing an amino group or 1 mol of the boron compound, it may be difficult to obtain the effect of adding component (b) as described above. Moreover, if the amount of component (b) exceeds 5 moles, it may become cloudy.

As the metal alkoxide condensate of component (b), there can be mentioned a metal alkoxide condensate represented by at least one formula selected from the group consisting of the following formulas (b1) and (b2).

(In the formula, R ³ represents an alkyl group, a part of which may be hydrogen, each R ³ may be independently the same or different, and m is selected from 2 to 20. (M represents at least one metal selected from the group consisting of Si, Ti, and Zr.)

The amount of the metal alkoxide condensate added as component (b) is preferably 2 to 50 moles, and 4 moles or more, based on the mass of the metal alkoxide monomer, per 1 mole of the amino group-containing silane compound. It is more preferable to have one. (b) If the amount of the component added is too large, the hardness of the resulting coating tends to decrease; on the other hand, if it is too small, the metal element content decreases, so depending on the application, the resulting coating may become hard. Hardness may decrease and chemical durability issues may occur. Furthermore, if the amount of component (b) added is too large, the curing time to obtain the coating film of the present disclosure tends to become longer.

R ³ in the metal alkoxide condensate that is component (b) represents an alkyl group, a part of which may be hydrogen, and each R ³ may be independently the same or different. However, R ³ is a methyl group, an ethyl group, a propyl group, a butyl group, or an alkyl group having more carbon atoms, and is preferably a methyl group or an ethyl group. Furthermore, m in the metal alkoxide condensate, which is component (b), represents an integer selected from 2 to 20, preferably 3 to 10, and most preferably 5. Furthermore, M in the metal alkoxide condensate as component (b) represents at least one metal selected from the group consisting of Si, Ti, and Zr, preferably Si or Ti; Most preferred is Si.

The metal alkoxide monomer units constituting the metal alkoxide condensate which is component (b) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, and propyltrimethoxysilane. Propoxysilane, butyltributoxysilane, tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, methyltrimethoxytitanium, ethyltriethoxytitanium, propyltripropoxytitanium, butyltributoxytitanium, tetramethoxyzirconium, tetraethoxy Examples include zirconium, tetrapropoxyzirconium, tetrabutoxyzirconium, methyltrimethoxyzirconium, ethyltriethoxyzirconium, propyltripropoxyzirconium, and butyltributoxyzirconium.

When component (b) is represented by the formula (b1), it is preferably a condensate of tetraethoxysilane (pentamer) or a condensate of tetramethoxysilane (pentamer), and the formula ( When represented by b2), it is preferably a condensate of ethyltriethoxysilane (pentamer) or a condensate of methyltrimethoxysilane (pentamer).

As described above, a metal alkoxide (monomer) and/or a metal alkoxide condensate is added to the reaction product of the present disclosure as component (b). The viscosity of the metal alkoxide monomer is lower than that of the condensate, so adding more metal alkoxide monomer may improve the coating properties of the resulting coating solution. If the amount is increased, such as by the same amount as the condensate, the viscosity of the coating liquid tends to decrease, and liquid dripping may easily occur when applied.

<About component (c)>
The synthetic resin as component (c) is preferably added to the reaction product. That is, a synthetic resin is added as component (c) during or after the reaction of the amino group-containing silane compound and the boron compound. By adding component (c), crack prevention properties can be imparted to the resulting film.

The synthetic resin of component (c) is not particularly limited, but may include thermosetting resins, thermoplastic resins, ultraviolet curable resins, etc. Specifically, acrylic resins, epoxy resins, polyester resins, Examples include amino resins, urethane resins, furan resins, silicone resins, and modified products of these resins, and synthetic resins having various degrees of polymerization (molecular weight) can be used. Among these, epoxy resin, dipentaerythritol hexaacrylate, epoxy acrylate, silicone resin, vinyl ester resin, polyvinyl butyral, polyvinyl alcohol, etc. are preferred. Moreover, the form of the synthetic resin is preferably liquid.

The amount of component (c) used is preferably 5 to 30% by mass based on the total solid content. More preferably, the ratio is 10 to 20% by mass. If component (c) is less than 5% by mass, it may be difficult to obtain the effect of adding component (c) as described above, and if component (c) is more than 30% by mass, the resin curing agent It may be necessary to add , and it may not be possible to impart high hardness to the resulting coating.

<About component (d)>
As component (d), a triazine ultraviolet absorber having an SP value of 10 to 13.5 (cal/cm ³ ) ^1/2 is used. For example, BASF TINUVIN400 (SP value: 11.0 (cal/cm ³ ) ^1/2 ), TINUVIN460 (SP value: 10.9 (cal/cm ³ ) ^1/2 ), TINUVIN479 (SP value: 11.3 (cal/cm ³ ) ^1/2 ), TINUVIN477 (SP value: 11.4 (cal/cm ³ ) ^1/2 ), and the like. The reason why good results are obtained with triazine-based ultraviolet absorbers is not clear, but it is thought that this is because the absorbers have high ultraviolet absorption ability and good weather resistance.

<About (e) component>
Component (e) serves as a solvent in each coating solution, and consists essentially of a non-aqueous solvent having an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 . "A nonaqueous solvent with an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 " means "a nonaqueous solvent with an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2" Single type of non-aqueous solvent", "Only non-aqueous solvents with an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 are combined, and the SP value of the mixed solvent is 8 to 11.5 (cal/cm 3 ) 1/2. cm ³ ) ^1/2 ,” and “A non-aqueous solvent with an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 is combined with a solvent with an SP value other than that. "A solvent in which the SP value of the mixed solvent falls within the range of 8 to 11.5 (cal/cm ³ ) ^1/2 ." In addition, the SP value of the mixed solvent can be calculated from the following calculation formula when two types, "solvent A" and "solvent B" are used, for example.

If the SP value of the solvent contained in the coating solution is 8 to 11.5 (cal/cm ³ ) ^1/2 , the ultraviolet absorber used in the present disclosure can be uniformly dispersed in the coating solution. As a result, the ultraviolet absorbent can be uniformly dispersed in the resulting film. In addition, if the SP value of the solvent is less than 8, the ultraviolet absorber may precipitate from the coating film after coating, and the ultimately obtained coating may become opaque.

Further, when the solvent contained in the coating liquid of the present disclosure is substantially composed of a non-aqueous solvent having an SP value of 8 to 10.5 (cal/cm ³ ) ^1/2 , the resulting coating Since the leveling property of the liquid is improved, leveling of the coating film can be completed in a shorter time when performing the leveling step described below, which is preferable.

Examples of the non-aqueous solvent having an SP value of 8 to 11.5 (cal/cm ³ ) ^1/2 include toluene, an aromatic hydrocarbon (SP value: 9.1 (cal/cm ³ ) ^1/2 ), xylene (SP value: 9.1 (cal/cm ³ ) ^1/2 ), acetic acid esters ethyl acetate (SP value: 8.8 (cal/cm ³ ) ^1/2 ), butyl acetate (SP value :8.7 (cal/cm ³ ) ^1/2 ), ketones acetone (SP value: 9.1 (cal/cm ³ ) ^1/2 ), methyl ethyl ketone (SP value: 9.0 (cal/cm ^{3 )} ) ^1/2 ), methyl isobutyl ketone (SP value: 8.3 (cal/cm ³ ) ^1/2 ), cyclohexanone (SP value: 9.8 (cal/cm ³ ) ^1/2 ), 2-heptanone ( SP value: 8.5 (cal/cm ³ ) ^1/2 ), glycol ethers 3-methoxy-3-methylbutanol (SP value: 10.5 (cal/cm ³ ) ^1/2 ), 1-methoxy -2-propanol (SP value: 11.3 (cal/cm ³ ) ^1/2 ), 1-ethoxy-2-propanol (SP value: 10.9 (cal/cm ³ ) ^1/2 ), 3-methoxy Butyl acetate (SP value: 8.8 (cal/cm ³ ) ^1/2 ), diethylene glycol monobutyl ether (SP value: 10.5 (cal/cm ³ ) ^1/2 ), ethers THF (SP value: 8 .3 (cal/cm ³ ) ^1/2 ), cellosolves such as ethylene glycol monoethyl ether (SP value: 11.5 (cal/cm ³ ) ^1/2 ), ethylene glycol mono-normal butyl ether (SP value: 10. 8 (cal/cm ³ ) ^1/2 ), 2-methoxybutyl acetate (SP value: 9.0 (cal/cm ³ ) ^1/2 ), dichloromethane of chlorinated hydrocarbons (SP value: 10.2 (cal /cm ³ ) ^1/2 ), and others include N,N-dimethylformamide (SP value: 10.2 (cal/cm ³ ) ^1/2 ), among which ketones such as methyl ethyl ketone (SP value: 9. 0 (cal/cm ³ ) ^1/2 ), methyl isobutyl ketone (SP value: 8.3 (cal/cm ³ ) ^1/2 ), cyclohexanone (SP value: 9.8 (cal/cm ³ ) ^1/2 ) ), 2-heptanone (SP value: 8.5 (cal/cm ³ ) ^1/2 ) and glycol ethers such as 3-methoxy-3-methylbutanol (SP value: 10.5 (cal/cm ³ ) ^{1/2). 2} ), 1-methoxy-2-propanol (SP value: 11.3 (cal/cm ³ ) ^1/2 ), 1-ethoxy-2-propanol (SP value: 10.9 (cal/cm ³ ) ^{1/ 2} ) is preferred.

Further, in addition to the component (e), each coating liquid may contain a solvent having an SP value other than 8 to 11.5 (cal/cm ³ ) ^1/2 , such as n-hexane (SP value: 7.3 (cal/cm ³ ) ^1/2 ), diethyl ether (SP value: 7.3 (cal/cm ³ ) ^1/2 ), 2-methoxyethanol (SP value: 12.0 (cal/cm 3 ) 1/2), cm ³ ) ^1/2 ), carbon tetrachloride (SP value: 12.2 (cal/cm ³ ) ^1/2 ), and the like.

The component (e) is preferably used when the UV absorber is used, but when the UV absorber is not used, each coating liquid contains, in addition to the component (e), Other solvents such as water, alcohols, ketones, etc. may also be included.

<About (f) component>
The pigment of component (f) is selected depending on the color of the first colored film. Blue pigments such as Pigment Blue 15 and Pigment Blue 28, cesium tungsten oxide (CWO) fine particles, green pigments such as Pigment Green 36 and Pigment Green 56, and yellow pigments such as Pigment Yellow 150 and Pigment Yellow 11. 9. As a red pigment, for example, PigmentRed101, PigmentRed254, as an orange pigment, for example, PigmentOrange71 Examples of the black pigment include Pigment Black 26, and examples of the pink pigment include Pigment Red 202 and Pigment Violet 19. The average particle diameter D ₅₀ of the pigment is preferably 10 to 300 nm. When D ₅₀ is less than 10 nm, there is a tendency for aggregation to occur, and when it exceeds 300 nm, visible light transmittance tends to deteriorate. Taking these into consideration, the average particle diameter D ₅₀ of the pigment is preferably 15 to 280 nm, more preferably 20 to 250 nm. Incidentally, the above-mentioned _D50 refers to the cumulative 50% particle size in the particle size distribution obtained by measuring the volume distribution of the pigment particles in water by a dynamic scattering method.

The pigment can be contained in the first coating liquid in a mass ratio of 0.02 to 0.50 times as much as the ultraviolet absorber (d). If it is less than 0.02 times, the color development of the first colored film tends to deteriorate, and if it exceeds 0.50 times, haze tends to increase. Taking these into consideration, it is preferable that the first coating liquid contains the pigment in a mass ratio of 0.025 to 0.45 times, more preferably 0.03 to 0.36 times, relative to the ultraviolet absorber. The second coating liquid (A) contains a pigment, and its content is adjusted to be lower than the visible light transmittance of the first colored coating. When the second coating liquid (A) contains the ultraviolet absorber as component (d), it may be contained less than 0.02 times in mass ratio to the ultraviolet absorber.

<Other ingredients>
Each of the coating liquids may contain fine particles made of a conductive substance. By including fine particles made of a conductive substance, infrared shielding properties can be provided to the plate glass with a colored coating. Examples of the conductive material include ITO (indium tin oxide) and ATO (antimony tin oxide). The content may be 5 to 15% by mass based on the total solid content, and the average particle diameter _D50 may be 50 to 100 nm. In addition to the above-mentioned components, each of the coating liquids may also contain antifungal agents, photocatalytic materials, rust preventive agents, anticorrosive agents, algae preventive agents, water repellents, oil repellents, light stabilizers, oxidation An inhibitor, a substrate wetting agent, a hydrophilic material, a water-absorbing material, etc. may also be included.

<First manufacturing method of vehicle window glass>
The vehicle window glass 1 shown in FIGS. 1 and 2 can be manufactured by applying each of the coating liquids to the concave main surface 21 or the convex main surface 22 of the curved glass plate 2.
The first manufacturing method of the vehicle window glass 1 includes:
A curved glass plate 2 having a main surface (concave main surface 21 and convex main surface 22), and a first colored coating formed on the main surface (concave main surface 21 or convex main surface 22). A method for manufacturing a vehicle window glass 1 comprising a coating part 31 and a second coating part 32 made of a second colored coating or a colorless coating having a higher visible light transmittance than the first colored coating,
a step (1) of preparing the first coating liquid and the second coating liquid ((A) or (B));
Step (2a) of preparing a liquid film 61 of the first coating liquid by spraying a mist 51 of the first coating liquid onto a portion where the first coating portion 31 is to be formed using a spray method. and,
A mist 52 of the second coating liquid is sprayed onto the area where the second coating portion 32 is to be formed using a spray method, thereby forming a liquid film 62 of the second coating liquid and a liquid film 62 of the first coating liquid. a step (2b) of preparing the liquid film 62 of the second coating liquid so that the liquid film 61 is integrated with the liquid film 61 to form a mixed liquid film 63 of the liquid film 61 and the liquid film 62;
a step (3) of drying and curing each liquid film,
In the step (2b), before the droplets 71 of the first coating liquid formed in the area where the second coating part 32 is to be formed by the mist 51 of the first coating liquid in the step (2a) are dried. Then, a mist 52 of the second coating liquid is sprayed to prepare a liquid film 62 of the second coating liquid.

The first manufacturing method will be explained with reference to FIGS. 4 and 5. FIG. 4 is a diagram schematically explaining the first manufacturing method, in which a first coating liquid is sprayed from a first spray nozzle 81 to prepare a liquid film 61 of the first coating liquid that will become the first coating portion 31. This is a schematic representation of the situation. FIG. 5 shows that after a liquid film 61 is formed by a first spray nozzle 81, a second coating liquid is sprayed from a second spray nozzle 82 to form a liquid film 62 of the second coating liquid and a liquid film 61 and a liquid film 62. This is a schematic representation of a state when forming a mixed liquid film 63. The spray nozzles 81 and 82 spray the coating liquid from the tip of the spray nozzle while moving, for example, in the direction of the arrow in FIGS. 4 and 5, and apply the coating liquid to the glass plate 2. A liquid film is formed.

After the liquid film 61 is formed, a liquid film 62 is formed adjacent to the edge of the liquid film 61 while maintaining the fluidity of the liquid film 61, so that both liquids are formed at the edge. Membranes 61 and 62 are mixed. As a result, the edge becomes the mixed liquid film 63. By setting the coating conditions for the first coating liquid and the coating conditions for the second coating liquid to be the same, the liquid films 61, 62, and 63 can be easily integrated with a uniform thickness. Then, by adjusting the solid content concentration of the coating liquid so that the film thickness obtained from each coating liquid is approximately the same, a uniform film is formed in the first coating part 31 and the second coating part 32. It becomes easier to obtain a thick, integrated coating. From the viewpoint of an integrated coating having a uniform thickness, it is preferable that the difference between the thickness of the first coating part 31 and the thickness of the second coating part 32 is small. The ratio of the thickness of the second coating portion 32 to the thickness of the second coating portion 32 is preferably within a range of 0.80 to 1.20, more preferably within a range of 0.95 to 1.05. Two spray nozzles may be used as the spray nozzles 81 and 82. Further, the coating liquid discharged from one spray nozzle is switched between the first and second coating liquids by operating the valve of the pipe through which the first and second coating liquids flow, The spray nozzle for discharging the first coating liquid may be the spray nozzle 81, and the spray nozzle for discharging the second coating liquid may be the spray nozzle 82.

<Second manufacturing method for vehicle window glass>
Moreover, the second manufacturing method of the vehicle window glass 1 includes:
A curved glass plate 2 having a main surface (concave main surface 21 and convex main surface 22), and a first colored coating formed on the main surface (concave main surface 21 or convex main surface 22). A method for manufacturing a vehicle window glass comprising a coating part 31 and a second coating part 32 made of a second colored coating or a colorless coating having a higher visible light transmittance than the first colored coating,
Step (1) of preparing a first coating liquid for forming the first coating part and a second coating liquid ((A) or (B)) for forming the second coating part;
Step (2c) of preparing a liquid film 62 of the second coating liquid by spraying a mist 52 of the second coating liquid onto a portion where the second coating portion 32 is to be formed using a spray method. and,
A mist 51 of the first coating liquid is sprayed onto the area where the first coating portion 31 is to be formed using a spray method to form a liquid film 61 of the first coating liquid and a layer of the second coating liquid. a step (2d) of preparing the liquid film 61 of the first coating liquid so that the liquid film 62 is integrated with the liquid film 62 to form a mixed liquid film 63 of the liquid film 61 and the liquid film 62;
a step (3) of drying and curing each liquid film,
In the step (2d), before the droplets 72 of the second coating liquid formed at the formation site of the first coating part by the mist 52 of the second coating liquid in the step (2c) dry. , spraying a mist 51 of the first coating liquid to prepare a liquid film 61 of the first coating liquid.

The second manufacturing method will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram schematically explaining the second manufacturing method, in which the second coating liquid is sprayed from the second spray nozzle 82 to prepare a liquid film 62 of the second coating liquid that will become the second coating portion 32. This is a schematic representation of the situation. FIG. 7 shows that after a liquid film 62 is formed by the second spray nozzle 82, the first coating liquid is sprayed from the first spray nozzle 81 to form a liquid film 61 of the first coating liquid and a liquid film 61 and a liquid film 62. This is a schematic representation of a state when forming a mixed liquid film 63. The spray nozzles 81 and 82 spray the coating liquid from the tip of the spray nozzle while moving, for example, in the direction of the arrow in FIGS. 6 and 7, and apply the coating liquid to the glass plate 2. A liquid film is formed.

Two spray nozzles may be used as the spray nozzles 81 and 82. In addition, the coating liquid discharged from one spray nozzle is switched between the first and second coating liquids by operating the valve of the pipe through which the first and second coating liquids flow. The spray nozzle for discharging the first coating liquid may be the spray nozzle 81, and the spray nozzle for discharging the second coating liquid may be the spray nozzle 82.

The first manufacturing method and the second manufacturing method are the same manufacturing method except for the order in which the first coating liquid and the second coating liquid are applied to the glass plate 2.

<Spray coating process of coating liquid>
In the method of spraying the coating liquid from a spray nozzle to coat the glass plate 2, as shown in FIGS. Mist 51a, 52a that diffuses and spreads from 51, 52 is generated. Therefore, each coating liquid is scattered outside the area to be applied, and droplet-like objects 71 and 72 are formed on the main surface of the glass plate 2. In the present disclosure, since the liquid film 63 is formed including the droplets 71 and 72 before the droplets 71 and 72 are dried, the droplets 71 and 72 are diffused within the liquid film 63. However, the droplet-like objects 71 and 72 disappear, and poor appearance of the coating caused by the droplet-like objects 71 and 72 can be suppressed. Since the total amount of the droplets 71 and 72 is very small compared to the total amount of the film, it has almost no effect on the formed film, and visually, it does not affect the color of the film.

The mist sprayed from the spray nozzle is a collection of droplets of the coating liquid. The size of the droplet may be 1 μmφ to 500 μmφ when the droplet is considered to be spherical. The size of the droplets can be adjusted by adjusting the pressure conditions of the spray nozzle, the viscosity of the coating liquid, and the like. The state of the droplets 71 and 72 formed based on the mist changes depending on the distance from the edges of the liquid films 61 and 62. The droplets 71 and 72 have various shapes, and as they move away from the edges of the liquid films 61 and 62, most of them are hemispherical, and as they get closer to the edges, the spheres randomly connect with each other and take on an amorphous shape. Become.

In the first manufacturing method, the liquid film 62 is formed including the droplet-like material 71 before the droplet-like material 71 is dried, so that even the droplet-like material 71 is not dried when the liquid film 62 is formed. Therefore, the liquid film 61 remains in a liquid state. Therefore, a mixed liquid film 63 of the liquid film 61 and the liquid film 62 is formed in the boundary area between the liquid film 61 and the liquid film 62. On the other hand, in the second manufacturing method, the liquid film 61 is formed including the droplets 72 before the droplets 72 are dried, so when the liquid film 61 is formed, even the droplets 72 are Since it is not dry, the liquid film 62 remains in a liquid state. Therefore, a mixed liquid film 63 of the liquid film 61 and the liquid film 62 is formed in the boundary area between the liquid film 61 and the liquid film 62.

In order to make the thicknesses of the liquid films 61 and 62 the same, the amount of each coating liquid applied is adjusted, and each liquid film is uniformly coated with the liquid film 61, the liquid film 62, and the mixed liquid film 63 formed. It is preferable to leave the glass plate 2 still, that is, to provide a leveling process so as to form a liquid level state. The leveling step is preferably carried out at room temperature for 5 to 20 minutes. Further, in the leveling step, ultrasonic vibration may be applied to the glass plate 2 to promote the formation of a uniform liquid surface state in each liquid film.

<Drying and curing process of coating liquid film>
After forming each liquid film on the glass plate 2, a drying process is performed to evaporate the solvent in each liquid film. This drying step may be performed by heating the glass plate 2 on which the liquid film has been formed at 20° C. to 300° C., or may be left standing at room temperature to dry. Next, by exposing to heat and steam at 100 to 350°C, the coating film (the liquid film from which the solvent has evaporated is referred to as the coating film) is cured, and the first coating portion 31 is formed on the main surface of the glass plate 2. , a second coating portion 32, and a boundary portion 33 are formed. In order to stabilize the temperature of the glass plate 2 and the amount of water vapor brought into contact with the coating film, it is preferable to perform the curing process within a chamber. It is more preferable to expose the glass plate 2 on which the coating film is formed to superheated steam at a temperature of over 100° C. to 350° C., since the dehydration condensation reaction proceeds in a short time and a highly hard coating can be obtained. More preferably, the temperature of the superheated steam is over 100°C to 300°C. It should be noted that superheated steam is steam at a temperature exceeding 100°C obtained by further heating saturated steam at 100°C.

As a more specific example, the vehicle window glass of the present disclosure will be described below using Examples and Comparative Examples.

Example 1
Step of preparing the first coating liquid and the second coating liquid <Preparation of the first coating liquid (coating liquid for the first coating portion 31)>
In a reaction vessel, 1.61 g of boric acid (H ₃ BO ₃ ) powder was added as component (a-2) to 9.72 g of 3-aminopropyltriethoxysilane liquid as component (a-1) (( Component (a-2) was added at a ratio of 0.6 mol to 1 mol of component a-1)), and after stirring for 5 minutes at 23°C, 17.38 g of tetramethoxysilane was added as component (b) ( Component (b) was added at a ratio of 2.6 mol to 1 mol of component (a-1)), and 5.08 g of epoxy resin CY232 manufactured by Nagase ChemteX (total solid After addition, the mixture was reacted at 60° C. for 120 hours to form a viscous liquid.

To this liquid, 37.22 g of 2-heptanone (SP value: 8.5 (cal/cm ³ ) ^1/2 ) as a solvent for component (e) and 3-methoxy-3-methylbutanol (SP value) of glycol ethers were added. :10.5 (cal/cm ³ ) ^1/2 ) 22.78 g was added, and triazine-based UV absorber TINUVIN460 manufactured by BASF (SP value: 10.9 (cal/cm ³ ) ^1/2 ), 1.35 g of TINUVIN477 (SP value: 11.4 (cal/ ^cm3 ) ^1/2 ), 0.47g of TINUVIN292 as a light stabilizer, Shin-Etsu Silicone as a surface conditioner. 0.68 g of ITO fine particle dispersion (solid content concentration: 20%) as a conductive substance, 2.20 g in terms of ITO fine particles as a conductive substance, pigment dispersion (solid content concentration: 10%, Carbon black was used as a black pigment.) was added in an amount of 0.51 g in terms of carbon black to obtain a coating liquid having a solid content concentration of 21% by mass. Note that the SP value of the solvent contained in the coating liquid is 9.0 (cal/cm ³ ) ^1/2 .

The prepared coating solution was colored and transparent. Furthermore, no clouding due to aggregation or the like was observed, and the ultraviolet absorber and carbon black were uniformly dispersed in the coating solution.

<Preparation of second coating liquid (coating liquid for second coating portion 32)>
The ultraviolet absorber, light stabilizer, conductive substance, and pigment dispersion used in the first coating liquid were omitted, and the other components were the same. The amounts of each component were adjusted so that the solid content concentration was 21% by mass, the same as that of the first coating liquid, and this was used as the second coating liquid.

<Preparation of glass plate>
A glass plate 2 made of green glass (commonly known as MFL) manufactured by Central Glass and having a thickness of 3.1 mm and curved for vehicle window glass was prepared. The size of the glass plate 2 was 1200 mm (horizontal direction) x 500 mm (vertical direction), and had three-dimensional bending.
In addition, the peripheral edge of the concave main surface 21 of the glass plate has a width of 40 mm (there is a part where the width is 110 mm in the central area of the upper side), which is made of black ceramic paste. A band-shaped visible light shielding layer (black ceramic) 4 with a thickness of 12.5 μm is arranged, and furthermore, a band-shaped visible light shielding layer (black ceramic) 4 with a width of 0.45 mm and a thickness of 10 μm formed of silver paste is disposed on the concave main surface 21. Linear conductive patterns are arranged at intervals of 31 mm. Further, the concave main surface 21 was polished with ceria powder, washed with water, and dried immediately before the first coating liquid and the second coating liquid were applied.

The forming part of the second coating part 32 assumes installation of a high-mounted stop lamp, and starts from the edge of the visible light shielding layer 4 on the upper side of the glass plate 2, and extends 50 mm vertically to the center side of the transparent part of the glass plate 2. It was set to be a rectangle with a width of 250 mm.

<Spray device>
A bell cup rotary atomizing air spray gun (manufactured by Asahi Sunac, ASG200) attached to the tip of the robot is used as the first spray nozzle 81 and second spray nozzle 82 for applying the first and second coating liquids. there was. The conditions during coating were as follows: bell cup rotation speed at 20,000 rpm, wide shape air at 0.05 MPa, and short shape air at 0.10 MPa.

Process of preparing a liquid film of the first coating liquid <Mist spraying of the first coating liquid>
The glass plate 2 was placed approximately horizontally with the concave main surface 21 facing upward and the convex main surface 22 facing the ground. While keeping the distance between the tip of the spray nozzle 81 and the concave side main surface 21 at 85 mm and scanning the spray nozzle 81 on the concave side main surface 21 under computer control, A mist 51 of the first coating liquid was sprayed to form a liquid film 61 of the first coating liquid on the concave main surface 21 . The liquid film 61 of the first coating liquid was formed in other regions except for the region where the second coating portion 32 was formed.

At this time, droplets 71 of the first coating liquid were formed in the second coating liquid application area outside the region where the liquid film 61 of the first coating liquid was formed. The shapes of the droplet-like objects 71 varied, and when the distance was 40 mm or more from the edge of the liquid film 61, most of the droplets were hemispherical, with a radius of 10 μm to 50 μm. In a range of 20 to 40 mm from the edge of the liquid film 61, in addition to the hemispherical droplets, hemispheres were randomly connected to form an amorphous shape. The maximum length of the irregularly shaped liquid was about 200 to 500 μm. In the range of 0 to 20 mm from the edge of the liquid film 61, the liquid film 61 had an irregular shape and a thin film having a thickness of 1.0 μm. Any of the above was observed on the entire surface of the area coated with the second coating liquid.

Process of preparing a liquid film of the second coating liquid <Mist spraying of the second coating liquid>
Next, while keeping the distance between the tip of the spray nozzle 82 and the concave side main surface 21 at 85 mm, and while scanning the spray nozzle 82 on the concave side main surface 21, A mist 52 of the second coating liquid was sprayed to form a liquid film 62 of the second coating liquid on the remaining part of the concave main surface 21 where the liquid film 61 of the first coating liquid was not formed. In forming the liquid film 62 of the second coating liquid, the mist 52 of the second coating liquid is sprayed before the droplets 71 dry, and the liquid film 61 of the first coating liquid and the second coating liquid are scattered. In the boundary area with the liquid film 62 of the two coating liquids, the scan width is adjusted so that both liquid films 61 and 62 are integrated, and specifically, the thickness of the mixed liquid film 63 is equal to that of the liquid films 61 and 62. A mixed liquid film 63 was prepared by adjusting the discharge amount and coating speed of the second coating liquid under computer control. The conditions for discharging the liquid film 61 of the first coating liquid onto the concave main surface 21 and the conditions for discharging the liquid film 62 of the second coating liquid onto the concave main surface 21 were the same.

The glass plate 2 on which the liquid film 61 of the first coating liquid and the liquid film 62 of the second coating liquid were formed was left horizontally for 15 minutes.

Step of drying and curing each liquid film Next, the glass plate 2 on which the liquid film 61 of the first coating liquid and the liquid film 62 of the second coating liquid were formed is placed in a hot air circulation oven at 180°C. Each liquid film was dried by heating for 5 minutes. After this heating, the article was exposed to superheated steam at 180° C. for 10 minutes. Through the above steps, a vehicle window glass 1 was obtained. In the vehicle window glass 1 of this example, a boundary portion 33 was formed between the first coating portion 31 and the second coating portion 32.

Evaluation of vehicle window glass The vehicle window glass 1 of this example was evaluated by the following evaluation method. Various evaluation results are shown in Table 1. In the boundary part 33, the visible light transmittance gradually increased from the first coating part 31 side to the second coating part 32 side, and the boundary part 33 became inconspicuous.

[exterior]
Visual observation at a distance of 800 mm from the light source under an environment with an illuminance of 1000 lux revealed that the coating of the vehicle window glass 1 was cracked, discolored, and cloudy (the ultraviolet absorber was uniformly dispersed in the coating due to aggregation, etc.). It was confirmed that there were no external defects such as optical distortion, spray mist marks, etc. At the same time, the width of the boundary portion 33 was measured using a caliper.

[Film thickness]
The film thickness of the coating on the vehicle window glass 1 was measured using a surfcorder ET4000A manufactured by Kosaka Institute.

[Visible Light Transmittance]
Using a spectrophotometer U-4100 manufactured by Hitachi, the visible light transmittance of the vehicle window glass 1 was calculated in accordance with JIS R3212 (2015). In the measurements, both the first coating portion 31 and the second coating portion 32 were measured near the center of their respective coating regions. In addition, the transmittance of the boundary part 33 is determined in the vertical direction from the central edge of the glass plate 2 of the visible light shielding layer 4 (40 mm width area) on the upper side of the glass plate 2, in accordance with this embodiment. , 35mm, 50mm, and 65mm points. The measurement results for each are indicated in Table 1 as boundary portion 33(1), boundary portion 33(2), and boundary portion 33(3).

Comparative example 1
In forming the liquid film 62 of the second coating liquid, the vehicle was manufactured through the same operations as in Example 1, except that the mist 52 of the second coating liquid was sprayed after the droplets 71 had dried. Window glass 1 was obtained. In the vehicle window glass 1 of this comparative example, a distribution of spots was observed in the second coating portion 32, which was thought to be caused by the droplet-like material 71, and was inappropriate as a visible light transmitting region.

Comparative example 2
The vehicle window glass 1 was gotten. In the vehicle window glass 1 of this comparative example, optical distortion was observed at the boundary portion 33.

1 Window glass for vehicle 2 Curved glass plate 21 having a main surface Concave main surface 22 Convex main surface 31 First coating portion 32 Second coating portion 33 Boundary portion 4 Visible light shielding layer 51 Mist of first coating liquid 52 Mist of second coating liquid 61 Liquid film of first coating liquid 62 Liquid film of second coating liquid 63 Mixed liquid film 71 of liquid film 61 and liquid film 62 Liquid of first coating liquid applied outside the application target area Droplets 72 Droplets 81 of the second coating liquid applied outside the application target area First spray nozzle 82 Second spray nozzle

Claims (5)

a curved glass plate having a main surface;
On the main surface, a first coating portion consisting of a first colored coating, and a second coating portion adjacent to the first coating portion and consisting of a second colored coating or a colorless coating having a higher visible light transmittance than the first colored coating. A vehicle window glass comprising two coating parts,
The coatings of the first coating part and the second coating part are integral coatings with a uniform thickness,
The ratio of the thickness of the first coating part to the thickness of the second coating part is 0.80 to 1.20,
The lower limit of the thickness of the film integrated with the uniform film thickness is 1.5 μm,
The vehicle window glass has a boundary portion between the first coating portion and the second coating portion, in which visible light transmittance gradually changes from the first coating portion to the second coating portion. The vehicle window glass according to claim 1, wherein the second coating portion is surrounded by the boundary portion, and the boundary portion is surrounded by the first coating portion. The vehicle window glass according to claim 1 or 2, further comprising a visible light shielding layer immediately above the main surface, the visible light shielding layer being between the first coating portion and the main surface. The vehicle window glass according to any one of claims 1 to 3, wherein the first colored coating and the second colored coating both have the same pigment. 5. The vehicle window glass according to claim 1, wherein the visible light transmittance of the second colored coating is 20% or more higher than that of the first colored coating.

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