JP7356838B2 - automotive window glass - Google Patents

Description

The present invention relates to automobile window glass.

Automotive window glasses are laminated with various functional films that exhibit water repellency, light blocking performance, and the like. Such functional films can be laminated by various methods, and for example, Patent Document 1 discloses laminating functional films by a flow coating method. In the flow rot method, with the glass plate upright, the coating liquid for the functional film is sprayed from a nozzle from bottom to top along one side edge of the glass plate, and then applied in parallel along the top edge. and finally apply from top to bottom along the other side edge. Since the coating liquid applied to the upper edge flows downward along the glass plate, it is thereby possible to apply the coating liquid to the entire surface of one side of the glass plate.

JP 2016-20204 Publication

However, the flow coating method has a problem in that a large amount of coating liquid is used. That is, it is necessary to spray a larger amount of functional liquid onto the glass plate than the functional liquid that is actually laminated on the glass plate, resulting in a problem of high manufacturing cost. The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an automobile window glass that can reduce the amount of a coating liquid for a functional liquid.

Item 1. Automotive window glass,
curved glass plate,
a first functional film laminated on the concave surface of the glass plate;
Equipped with
The first functional film contains substantially only a composition soluble in a fluorine-based solvent,
An automobile window glass, wherein the ratio of the maximum film thickness to the minimum film thickness of the first functional film is 1.5 or less.

Item 2. The first functional film is a film having a water repellent function,
Item 2. The automobile window glass according to Item 1, wherein the first functional film has a thickness of 5 to 50 nm.

Item 3. The contact angle of water on the first functional film is 60° or more,
Item 3. The automobile window glass according to Item 2, wherein a falling angle of water in the first functional film is 20° or less.

Item 4. 4. The automobile window glass according to item 2 or 3, wherein the first functional film contains a coupling agent having an alkoxysilyl group.

Item 5. Item 4. The automobile window according to Item 4, wherein the first functional film has a water contact angle of 60° or more after a dry cloth is reciprocated 1500 times with a load of 1200 g/4 cm ² against the first functional film. glass.

Item 6. 6. The automotive window according to any one of Items 2 to 5, wherein the first functional film is directly laminated on the concave surface, and the first functional film has a surface roughness Ra of 0.5 to 3.0 nm. glass.

Section 7. Item 7. The automobile window glass according to any one of Items 2 to 6, wherein the first functional film contains the water-repellent composition having an average molecular weight of 1,000 or more and 30,000 or less.

Section 8. Item 8. The automobile window glass according to any one of Items 2 to 7, which is a side glass that can be raised and lowered.

Item 9. 9. The automobile window glass according to any one of Items 2 to 8, wherein the first functional film is formed to have a thickness that changes in a plane direction.

Item 10. Item 10. The automobile window glass according to Item 9, wherein the first functional film is formed so that concave and convex portions are lined up in one surface direction, and the pitch between adjacent convex portions is 20 to 150 mm.

Item 11. Any one of Items 2 to 10, further comprising a second functional film laminated on the convex surface of the glass plate and containing the same composition as the water-repellent composition of the first functional film. Automotive window glass described.

Item 12. Item 12. The automobile window glass according to item 11, wherein the first functional film and the second functional film have the same content of the composition exhibiting the water-repellent function.

According to the automobile window glass according to the present invention, it is possible to reduce the amount of the functional liquid coating liquid applied.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing an embodiment in which an automobile window glass according to the present invention is applied to a side glass. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a schematic diagram illustrating the bonding between the first functional film and the glass plate. FIG. 3 is a cross-sectional view illustrating the measurement of the thickness of the first functional film. FIG. 3 is a diagram illustrating application of a coating liquid for a first functional film by spraying. FIG. 3 is a cross-sectional view illustrating unevenness occurring in the first functional film.

First, an embodiment in which the automobile window glass according to the present embodiment is applied to a side glass will be described using FIGS. 1 and 2 with reference to the drawings. FIG. 1 is a plan view of a side glass according to this embodiment, and FIG. 2 is a cross-sectional view taken along the line AA in FIG.

<1. Overview of side glass＞
As shown in FIGS. 1 and 2, this side glass includes a trapezoidal glass plate 1 and a first functional film 2 laminated on a surface 101 of the glass plate 1 on the inside of the vehicle. This will be explained in detail below.

<1-1. Glass plate>
Each glass plate 1 is formed into a rectangular shape having an upper side 11, a lower side 12, a front side 13, and a rear side 14. The upper side 11 and the lower side 12 are formed in parallel, and the upper side 11 is shorter than the lower side 12. The front side 13 includes a first portion 131 that extends upward from the front end of the lower side 12 so as to be inclined toward the rear, and a second portion 132 that extends from the upper end of the first portion 131 so as to be inclined further toward the rear. We are prepared. Further, the rear side 14 extends upward from the rear end of the lower side 12 in a slightly curved and inclined manner toward the rear, substantially parallel to the first portion 131 of the front side 13 . Therefore, the rear end of the upper side 11 is located slightly rearward than the rear end of the lower side 12.

The side glass made up of the outer glass plate 1 and the inner glass plate 2 is attached to the door of a vehicle, and is supported by a lift module (regulator, not shown) provided inside the door, and is raised and lowered. It looks like this. When the side glass is raised and the window is closed, the lower side 12 of the side glass is positioned below the belt molding of the door. Therefore, the lower side 12 of the side glass is not visible from outside or inside the vehicle, regardless of whether the window is opened or closed. Further, while the side glass is rising, the first portion 131 of the front side 13 and the rear side 14 are supported by a guide (for example, a glass run) of the door frame and move up and down along this guide. Therefore, the first portion 131 of the front side 13 and the rear side 14 are accommodated in the guide and are not visible from outside and inside the vehicle. When the window is closed, the second portion 132 of the front side 13 and the upper side 11 are also accommodated within the door frame and cannot be seen from outside or inside the vehicle.

Further, as the glass plate 1, a known glass plate can be used, and it can also be formed of heat ray absorbing glass, general clear glass, green glass, or UV green glass. Examples of compositions of clear glass, heat ray absorbing glass, and soda lime glass are shown below.

(clear glass)
SiO ₂ :70-73% by mass
Al ₂ O ₃ :0.6-2.4% by mass
CaO: 7-12% by mass
MgO: 1.0 to 4.5% by mass
R ₂ O: 13 to 15% by mass (R is an alkali metal)
Total iron oxide (T-Fe ₂ O ₃ ) converted to Fe ₂ O ₃ : 0.08 to 0.14% by mass

(heat ray absorbing glass)
The composition of the heat ray absorbing glass is, for example, based on the composition of clear glass, the ratio of total iron oxide (T-Fe ₂ O ₃ ) converted to Fe ₂ O ₃ is 0.4 to 1.3% by mass, and CeO The ratio of TiO ₂ is 0 to 2% by mass, the ratio of TiO ₂ is 0 to 0.5% by mass, and the glass framework components (mainly SiO ₂ and Al ₂ O ₃ ) are replaced with T-Fe ₂ O ₃ and CeO ₂ and TiO ₂ can be reduced by the increment of TiO 2 .

(soda lime glass)
SiO ₂ :65-80% by mass
Al ₂ O ₃ : 0 to 5% by mass
CaO: 5-15% by mass
MgO: 2% by mass or more NaO: 10-18% by mass
K ₂ O: 0 to 5% by mass
MgO+CaO: 5-15% by mass
Na ₂ O + K ₂ O: 10-20% by mass
SO ₃ :0.05-0.3% by mass
B ₂ O ₃ : 0 to 5% by mass
Total iron oxide (T-Fe ₂ O ₃ ) converted to Fe ₂ O ₃ : 0.02 to 0.03% by mass

The thickness of this glass plate 1 is not particularly limited, but for example, it is preferably 2.4 to 4.6 mm, more preferably 2.6 to 3.4 mm, and 2.7 to 3.2 mm. It is particularly preferable to do so.

Further, as shown in FIG. 2, the glass plate 1 is curved so as to be convex toward the outside of the vehicle, and the first functional film 2 is laminated on the concave surface 101 on the inside of the vehicle. The radius of curvature of the concave surface 101 can be, for example, 15,000 to 50,000 mm, preferably 30,000 to 50,000 mm.

<1-2. First functional membrane>
Next, the first functional film 2 will be explained. The first functional film 2 according to this embodiment is formed of a water-repellent film having a water-repellent function.

This water-repellent film is characterized in that it contains substantially only a composition soluble in a fluorine-based solvent. Such a composition is not particularly limited, but can include, for example, a compound represented by the following formula (X). Note that "only compositions that are substantially soluble in fluorinated solvents" does not mean, for example, excluding other compositions that have been mixed in during the manufacturing process; This means that contamination is allowed.

[Rf ^1- Z ¹ ] _a ^- Q ^1- [Z ^2- SiR _c M _3-c ] _b (X)
(In the formula, Rf ¹ is independently a monovalent perfluoropolyether group with a molecular weight of 400 to 20,000 composed of a perfluoroalkylene group having 1 to 6 carbon atoms and an oxygen atom, and Z ¹ is independently a carbon It is a divalent hydrocarbon group which may contain 1 to 20 oxygen atoms, nitrogen atoms, and silicon atoms, and may contain a cyclic structure in the middle.Z ² is independently 2 having 2 to 8 carbon atoms. is a valent hydrocarbon group. Q ¹ is an (a+b) valent linking group containing at least (a+b) silicon atoms, and may have a cyclic structure. a is an integer from 1 to 10, b is independently an integer from 1 to 10, and c is each independently 0, 1, or 2. In formula (X), a Z ¹ and b Z ² enclosed in brackets are all respectively It is bonded to the silicon atom in the Q ¹ or Q ² structure. R is independently a monovalent hydrocarbon group of 1 to 6. M is an alkoxy group or an alkoxyalkyl group, ^- SiR _c M _{3- c} is an alkoxysilyl group.)
The fluorine-containing reactive silane compound represented by can be exemplified as a composition that is substantially soluble in a fluorine solvent.

Here, as the fluorine-containing reactive silane compound represented by the above formula (X), those shown below can be exemplified.
(In the formula, r1 and Rf' are the same as above.)

The number average molecular weight of the fluoropolyether chain moiety in the perfluoroalkylene group is not particularly limited, but is, for example, 1,000 to 30,000, preferably 1,500 to 30,000, more preferably 2, 000 to 10,000. The above number average molecular weight is a value measured by ¹⁹ F ^- NMR. This is because when the number average molecular weight is 1000 or more, the bonding of molecules becomes long, and for example, even if oil adheres to the first functional membrane 2, as shown in FIG. This makes it possible to prevent a decrease in water repellency. On the other hand, if the number average molecular weight is too large, the number of alkoxysilyl groups bonded to the glass plate 1 may decrease. Therefore, when the number average molecular weight is 30,000 or less, the number of bonds with the OH groups of the glass plate 1 decreases, and a decrease in bond strength can be prevented.

On the other hand, when the number average molecular weight of the fluoropolyether chain is less than 1,000, the probability of reaction on the surface of the glass plate decreases even if an alkoxysilyl group is contained. As a result, there is a risk that the wear resistance will decrease.

The water-repellent function of the first functional film 2 means, for example, that the contact angle on the surface of the first functional film is 60° or more, preferably 80° or more, and more preferably 100° or more.

The composition constituting the first functional film 2 is dissolved in a fluorine-based solvent and then laminated on the glass plate 1 by a method described below. Examples of fluorine-based solvents include perfluorohexane, perfluorooctane, perfluoromethylcyclohexane, perfluorodimethylcyclohexane, perfluorodecalin, perfluoroalkylethanol, perfluorobenzene, perfluorotoluene, perfluoroalkylamine ( Fluorinert (trade name), etc.), perfluoroalkyl ether, perfluorobutyltetrahydrofuran, polyfluoroaliphatic hydrocarbon (Asahikulin AC6000 (trade name)), hydrochlorofluorocarbon (Asahikulin AK ^- 225 (trade name), etc.), Hydrofluoroether (Novec (product name), HFE ^- 7100 (product name), HFE ^- 7200 (product name), HFE-7300 (product name), HFE ^- 7000 ⁽ product name), Asahiklin AE ^- 3000 (product name) ), 1,1,2,2,3,3,4 ^- heptafluorocyclopentane, 1,1,1,3,3 ^- pentafluorobutane, fluorine-containing alcohol, perfluoroalkyl bromide, perfluoroalkyl iodide perfluoropolyether (Krytox (trade name), Demnum (trade name), Fomblin (trade name), etc.), 1,3 ^- bistrifluoromethylbenzene, ^2- (perfluoroalkyl)ethyl methacrylate, acrylic Acid ^2- (perfluoroalkyl)ethyl, perfluoroalkylethylene, Freon 134a, and hexafluoropropene oligomer, 1,2 ^- dichloro ^- 1,3,3,3 ^- tetrafluoro ^- 1 ^- propene, etc. can be mentioned. .

<2. Physical properties and performance of the first function>
<2-1. Film thickness>
The thickness of the first functional film 2 is not particularly limited, but is preferably, for example, 5 to 50 nm, more preferably 10 to 30 nm. If the thickness of the first functional film 2 exceeds 50 nm, the cost may increase. On the other hand, the first functional film 2 exhibits a water-repellent function even when the film thickness is as thin as a monomolecular film, but if the film thickness is smaller than 5 nm, for example, there is a risk that it will peel off from the glass plate 1 when an external force is applied before drying. be. Therefore, the thickness of the first functional film 2 is preferably 5 nm or more. The film thickness can be calculated by various methods, and for example, it can be measured by cutting the side glass at a location where the film thickness is desired and observing the cross section using an SEM or the like.

Observation with SEM can be performed, for example, as follows. A field emission scanning electron microscope S-4700 (manufactured by Hitachi High-Tech) is used, and the acceleration voltage is set to 5 kV. The first functional film 2 is then etched using 0.1% hydrogen fluoride. After coating with Pt--Pd for conductive treatment, observation by SEM is performed.

Moreover, when the film thickness becomes large, for example, the alkoxysilyl groups mentioned above become excessive, and those that do not bond to the glass plate 1 may appear on the surface of the first functional film 2, forming irregularities. Such unevenness may prevent water droplets from flowing smoothly, and as a result, water repellency may deteriorate.

Further, in the first functional film 2 according to the present embodiment, the ratio of the maximum film thickness to the minimum film thickness (hereinafter referred to as film thickness ratio) is 1.5 or less, preferably 1.3 or less, More preferably, it is 1.1 or less. Thereby, the thickness of the first functional film 2 can be made uniform over almost the entire concave surface 101. It is thought that when the film thickness is uniform, surface irregularities become smaller, thereby improving water repellency.

The film thickness ratio can be calculated as follows. This point will be explained with reference to FIG. 4 as well. First, considering the coating method described later, it is thought that the maximum film thickness occurs at the deepest part of the concave surface 101, and the film thickness at this part is defined as the maximum film thickness. On the other hand, the minimum film thickness tends to occur at the edges of the first functional film 2 (for example, it tends to occur at locations where the coating liquids from a plurality of nozzles do not overlap, as will be described later). Therefore, the minimum film thickness is determined by selecting five points that are 10 cm or more away from the edge of the first functional film 2 (the area where the coating liquid was applied by the nozzle 1), and from each point within the surface direction of the glass plate 1. This is the average film thickness at a position 5 mm inward. A film thickness ratio is calculated from the maximum film thickness and minimum film thickness thus measured.

<2-2. Surface roughness Ra>
The surface roughness Ra of the first functional film 2 is preferably 0.5 to 3.0 nm, more preferably 0.5 to 2 nm. This is because if the surface roughness Ra is less than 0.5 nm, the adhesion of the first functional film 2 to the glass plate 1 may deteriorate. On the other hand, when the surface roughness Ra exceeds 3.0 nm, attached water droplets are likely to be caught, and there is a possibility that the water repellent performance may deteriorate. Note that surface roughness can be measured as follows. The surface shape was measured in cyclic contact mode using an atomic force microscope ("SPA400", manufactured by Hitachi High-Tech Science Co., Ltd.), and the value was calculated as the arithmetic mean roughness Ra. The cantilever used was a silicon "SI ^- DF20", the measurement area of the sample was a square of 1 μm x 1 μm, the number of measurement points was 512 x 256, the scanning speed was 1.02 Hz, correction by a low-pass filter, and leveling correction of the measured data. The surface roughness (Ra) was calculated. The leveling correction of the measured data was performed by fitting a curved surface using least squares approximation, correcting the slope of the data, and removing distortion in the height direction.

<2-3. Contact angle of water＞
The contact angle of water in the first functional film 2 is preferably 60° or more, more preferably 80° or more, and particularly preferably 100° or more. The larger the contact angle, the better the static water repellency. Further, it is known that the contact angle is 120° or less as a general phenomenon. Note that the contact angle is measured using, for example, a contact angle measuring device (“DMs-401”, manufactured by Kyowa Interface Science Co., Ltd.) with 3 μL of water.

<2-4. Falling angle of water>
The falling angle is used as a measure of the ability of water droplets to roll on the surface of the first functional film 2. The measurement method is shown below. To measure the falling angle, a water droplet with a diameter of 5 mm is placed on the surface (for example, near the center) of the first functional film 2 arranged horizontally, and the glass plate 1 is gradually tilted. The angle of inclination of the glass plate 1 at which the water droplet placed on the surface starts rolling is defined as the falling angle of the water droplet. The falling angle measured in this manner is preferably 20° or less, more preferably 15° or less, and particularly preferably 12° or less. The smaller the falling angle, the better the dynamic water repellency, which means that, for example, raindrops that adhere to the vehicle while driving are more likely to scatter and prevent the occupant's view from being obstructed.

<2-5. Wear test>
The wear test can be performed, for example, as follows. That is, a flannel cloth (No. 300), which is a dry cloth, was attached to a reciprocating abrasion tester ("HEIDON-18" manufactured by Shinto Kagakusha), and a load of 1200 g/4 cm ² was applied to the surface of the first functional membrane 2. , make it reciprocate 1500 times. After this test, the contact angle of water on the first functional film 2 is preferably 60° or more, more preferably 100° or more. Even after such an abrasion test, if the contact angle of water on the first functional film 2 is 60° or more, even if friction occurs, such as when another object comes into contact with the first functional film 2, Decrease in water repellency can be suppressed.

<3. Manufacturing method of side glass＞
Next, a method for manufacturing the above-mentioned side glass will be explained. First, a curved glass plate 1 is formed by known press forming or the like. Then, this glass plate 1 is conveyed by a conveyor or the like with the concave surface 101 facing upward. During this transportation process, pretreatment is performed on the concave surface 101 of the glass plate 1 before applying the first functional film 2 thereon. Although the pretreatment is not particularly limited, examples thereof include plasma treatment (corona discharge, etc.), ion beam treatment, alkaline cleaning, Serico cleaning, and the like. Through such treatment, hydroxyl groups can be introduced or increased on the surface of the concave surface 101 of the glass plate 1, and the concave surface 101 can be cleaned, such as by removing foreign matter.

Note that after the Serico cleaning, the surface of the glass plate 1 has become hydrophilic, so the contact angle on the surface of the glass plate 1, that is, the surface before laminating the first functional film 2, is 100° or more. . Moreover, after the cerico cleaning, the surface roughness of the glass plate 1 is reduced. In particular, since the first functional film 2 is thin, the surface roughness Ra of the first functional film follows the surface roughness of the surface of the glass plate 1. As a result, the surface roughness Ra of the first functional film can be within the above range, that is, 3 nm or less.

Subsequently, a coating liquid for the first functional film 2 is applied to the concave surface 101 by spraying. Although the coating method using a spray device is not particularly limited, for example, as shown in FIG. 5, the glass plate 1 is conveyed by a conveyor. At this time, it is assumed that the glass plate 1 is transported in a direction perpendicular to the paper surface of FIG.

The spray device is provided with two nozzles 5 arranged in parallel above the glass plate 1. From each nozzle, the coating liquid for the first functional film 2 is sprayed toward the glass plate below at a coating angle θ of 100° or less. At this time, since the nozzles 5 are arranged close to each other, the coating liquid sprayed from the two nozzles 5 is applied so as to overlap. As mentioned above, since the coating liquid is sprayed from the nozzle 5 at a predetermined coating angle θ, on the concave surface of the glass plate 1, the amount of coating is the largest directly below the nozzle 5, and the amount of coating is smaller near the periphery. Conceivable. Furthermore, the amount of coating liquid sprayed from both nozzles 5 at the overlapping portion also increases. Note that the height from the surface of the conveyor on which the glass plate 1 is placed to the nozzle 5 can be, for example, 20 to 80 mm. Further, the amount of the coating liquid discharged from each nozzle 5 can be, for example, 50 to 200 g/min.

Furthermore, as described above, the coating liquid is discharged from the two nozzles 5 at a predetermined coating angle θ, and the coating liquid discharged from the two nozzles 5 is applied so as to overlap on the concave surface 101. Concave and convex portions are formed on the concave surface 101 along the surface direction. That is, as described above, the first functional film 2 after drying tends to have the largest thickness near the center of the concave surface 101, but also tends to become thickest directly below the nozzle 5. During this period, the film thickness tends to become smaller. Therefore, as shown in FIG. 6, in the direction perpendicular to the transport direction of the glass plate 1, at least three thick convex portions 21 and thin concave portions between them are formed. At this time, the distance L between the convex portions 21 (the distance between the tops of the convex portions) is preferably 20 to 150 mm, and preferably 75 to 120 mm. This is because if the distance between the convex portions 21 is less than 20 mm, the overall thickness of the first functional film 2 will increase, which may increase the cost. On the other hand, if the distance between the convex portions exceeds 150 mm, the film thickness of the first functional film 2 will vary greatly, and the film thickness will become non-uniform. Note that for the sake of explanation, FIG. 6 shows the unevenness of the film thickness with emphasis.

Note that in this embodiment, the coating liquid is sprayed from two nozzles 5, but three or more nozzles may be used. However, as the number of nozzles increases, it is thought that the unevenness formed on the first functional film 2 increases along the direction in which the nozzles are lined up, that is, the surface direction perpendicular to the transport direction. Even in that case, it is preferable to set the distance L between the convex portions 21 as described above.

After the coating liquid for the first functional film is applied to the concave surface 101 in this manner, moisture may be subsequently supplied to the surface of the coating liquid. Hydrolysis may be expected by supplying moisture.

The glass plate may then be heated, for example, at a temperature of 100 to 200°C. Under such an atmosphere, in the composition constituting the first functional film, the groups bonded to Si are rapidly dehydrated and condensed, and as a result, it is expected that the bonding between the composition and the concave surface 101 will be promoted. There are cases.

Furthermore, since the fluorine-based solvent contained in the coating liquid evaporates quickly, the coating liquid flows toward the center along the concave surface 101 and hardens before it accumulates, and the first functional film 2 is formed.

<4. Features＞
According to the side glass described above, the following effects can be obtained.
(1) The first functional film 2 contains only a composition soluble in a fluorine-based solvent. That is, the first functional film 2 is formed by coating the glass plate 1 with a coating liquid containing a fluorine-based solvent that evaporates easily and a composition that is soluble in the fluorine-based solvent. When such a coating liquid is applied to the concave surface 101 of the glass plate 1, the fluorinated solvent evaporates before the coating liquid completely accumulates near the center of the concave surface. Variations in the thickness of the functional film 2 can be suppressed.

Since the film thickness ratio of the first functional film 2 is 1.5 or less, the coating liquid can be applied by spraying, for example, instead of the flow coating method. Therefore, the amount of the coating liquid applied to the concave surface 101 can be adjusted to the minimum, so the amount of the coating liquid used can be reduced. As a result, manufacturing costs can be reduced.

(2) When the film thickness ratio of the first functional film 2 is small as described above, it is thought that the unevenness occurring on the surface of the first functional film 2 is suppressed and the thickness becomes uniform. Therefore, water droplets adhering to the first functional film 2 flow more easily, improving water repellency. In addition, the improvement in water repellency also suppresses the adhesion of dirt, resulting in improved antifouling performance.

<5. Modified example>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit thereof. Note that the following modifications can be combined as appropriate.

<5-1>
In the above embodiment, the first functional film 2 is laminated only on the concave surface 101 of the glass plate 1, but the functional film can also be applied to the convex surface 102. Here, the functional film laminated on the convex surface 102 will be referred to as a second functional film. For example, the first functional film 1 and the second functional film can contain compositions having the same water-repellent function as described above. In this case, the content of the compositions can be the same. That is, the first functional film 2 and the second functional film may be formed of the same material. Alternatively, the first functional film 2 and the second functional film may be formed of different materials.

<5-2>
In the embodiment described above, a water-repellent film having a water-repellent function is used as the first functional film 2, but the invention is not limited to this, and a functional film having other functions may be used. For example, an AR function film, a UV cut film, etc. can be used. Even if a functional film has such a function, as mentioned above, if it contains only a composition soluble in a fluorine-based solvent and has a film thickness ratio of 1.5 or less, Can be adopted as appropriate. Therefore, for example, a UV cut film can be applied to the concave surface 101 as the first functional film, and a water-repellent film can be applied to the convex surface 102 as the second brain membrane. Thereby, it is possible to reduce the amount of ultraviolet rays that enter the interior of the vehicle, thereby reducing the amount of ultraviolet rays that are irradiated to the driver.

<5-3>
The shape of the glass plate 1 is not particularly limited, and can be made into various shapes. Further, in the above embodiment, an example was explained in which the automobile window glass according to the present invention is applied to a side glass that can be raised and lowered, but the invention is not limited to this, and it can also be applied to a fixed side glass, a windshield, and a rear glass that cannot be raised or lowered. It can also be applied. Further, the glass plate can be formed not only from a single plate but also from laminated glass.

Examples according to the present invention will be described below. However, the present invention is not limited to the following examples.

First, glass plates and first functional films used in Examples and Comparative Examples were prepared as follows.

(1) Glass Plate A rectangular float glass plate with a size of 1000 x 500 mm and a thickness of 3 mm was prepared. Further, this glass plate was curved, and the radius of curvature of the concave surface was 650 mm.

(2) First functional film As the first functional film applied to the concave surface of the glass plate, a first water repellent made by dissolving KY-1901 manufactured by Shin-Etsu Chemical Co., Ltd. in a fluorine-based solvent and SIT8175.0 manufactured by Gelest were used. A second water repellent dissolved in alcohol was prepared and applied to the glass plate by spraying, and then dried in the same manner as in the above embodiment. The first water repellent contains an alkoxysilyl group as a coupling agent and has an average molecular weight of 1,000 or more. On the other hand, the second water repellent has an average molecular weight as a coupling agent of less than 1,000.

(3) Examples and Comparative Examples A first functional film was formed as follows. The glass plate is the same in the Examples and Comparative Examples. In addition, in Example 5, the first functional film of Example 1 was rubbed with a dry cloth, and the surface roughness Ra was made rougher than in Example 1. In Example 6, the first functional film of Example 1 was rubbed with a compress, and the surface roughness Ra was made even rougher than in Example 5.

(4) Evaluation Examples 1 to 4 and Comparative Examples 1 and 2 were subjected to the friction test described above. The results are as follows.

(5) Discussion Examples 1 to 6 all have a film thickness ratio of 1.5 or less, and due to this, the contact angles of Examples 1 to 4 do not decrease much even after the friction test. Similarly, it was found that the falling angles of Examples 1 to 4 did not decrease much even after the friction test. Furthermore, in Examples 5 and 6, the surface roughness of the first functional film was large, and it was found that the larger the surface roughness, the larger the falling angle. On the other hand, in both Comparative Examples 1 and 2, the film thickness ratio exceeds 1.5, which is thought to be due to the fact that alcohol is used as a solvent.

1 Glass plate 101 Concave surface 2 First functional film

Claims (12)

Automotive window glass,
curved glass plate,
a first functional film laminated on the concave surface of the glass plate;
Equipped with
The first functional film contains substantially only a composition soluble in a fluorine-based solvent,
The first functional film has the largest thickness near the center of the concave surface of the glass plate,
An automobile window glass, wherein the ratio of the maximum film thickness to the minimum film thickness of the first functional film is 1.5 or less.
The first functional film is a film having a water repellent function,
The automobile window glass according to claim 1, wherein the first functional film has a thickness of 5 to 50 nm. The contact angle of water on the first functional film is 60° or more,
The automobile window glass according to claim 2, wherein a falling angle of water in the first functional film is 20° or less. The automobile window glass according to claim 2 or 3, wherein the first functional film contains a coupling agent having an alkoxysilyl group. 5. The automobile according to claim 4, wherein the first functional film has a water contact angle of 60° or more after a dry cloth is reciprocated 1500 times with a load of 1200 g/4 cm ² against the first functional film. window glass. The automotive vehicle according to any one of claims 2 to 5, wherein the first functional film is directly laminated on the concave surface, and has a surface roughness Ra of 0.5 to 3.0 nm. window glass. The automobile window glass according to any one of claims 2 to 6, wherein the first functional film contains the water-repellent composition having an average molecular weight of 1,000 or more and 30,000 or less. The automobile window glass according to any one of claims 2 to 7, which is a side glass that can be raised and lowered. The automobile window glass according to any one of claims 2 to 8, wherein the first functional film is formed to have a thickness that changes in a plane direction. 10. The automobile window glass according to claim 9, wherein the first functional film is formed so that concave and convex portions are lined up in one surface direction, and the pitch between adjacent convex portions is 20 to 150 mm. Any one of claims 2 to 10, further comprising a second functional film laminated on the convex surface of the glass plate and containing the same composition as the water-repellent composition of the first functional film. Automotive window glass described in . The automobile window glass according to claim 11, wherein the first functional film and the second functional film have the same content of the composition exhibiting the water-repellent function.