Vehicle rear information acquisition system

Abstract

A vehicle rear information acquisition system according to the present disclosure comprises a back window mounted on the rear of the vehicle, and an information acquisition device that is disposed in the vehicle interior so as to face the back window and acquires information from outside of the vehicle by emitting and / or receiving light, wherein: the back window comprises a glass sheet and a coating film provided to at least one part of a surface of the glass sheet, and has a privacy region for protecting the privacy of the vehicle interior, and an information acquisition region through which the light can pass and which is opposite the information acquisition device; the coating film is provided to the surface of the glass sheet in the privacy region; the transmittance of visible light in the privacy region is no more than 10%; and the transmittance of visible light in the information acquisition region is at least 25%.

Description

[Technical Field]

[0001] The present disclosure relates to a system for obtaining information about the rear of a vehicle. [Background technology]

[0002] 2. Description of the Related Art Tinted glass such as gray glass is used for vehicle glass such as a back window attached to the rear of a vehicle in order to ensure privacy inside the vehicle.

[0003] Patent Document 1 describes, as an example of a gray glass composition, a composition that has soda-lime-silica glass as a base composition and contains iron oxide and the like as a coloring component. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-227839 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the number of vehicles that have information acquisition devices such as cameras mounted on the rear window to acquire information about the area behind the vehicle has increased. However, when the information acquisition device is placed inside the vehicle facing the rear window, the tint of the gray glass must be lightened to a certain extent to ensure the visibility of the information acquisition device. Therefore, it is difficult to achieve both privacy inside the vehicle and visibility of the information acquisition device.

[0006] The present disclosure has been made to solve the above problems, and aims to provide a vehicle rear information acquisition system in which an information acquisition device is arranged on the back window, which can ensure privacy inside the vehicle and visibility of the information acquisition device. [Means for solving the problem]

[0007] The vehicle rear information acquisition system of the present disclosure is a vehicle rear information acquisition system comprising a back window attached to the rear of the vehicle, and an information acquisition device arranged inside the vehicle facing the back window and acquiring information from outside the vehicle by irradiating and / or receiving light, wherein the back window comprises a glass plate and a coating provided on at least a portion of the surface of the glass plate, and has a privacy area for protecting privacy inside the vehicle, and an information acquisition area facing the information acquisition device through which the light passes, wherein the coating is provided on the surface of the glass plate in the privacy area, and the visible light transmittance of the privacy area is 10% or less, and the visible light transmittance of the information acquisition area is 25% or more.

[0008] The vehicle rear information acquisition system of the present disclosure uses a back window in which a coating is provided on at least a portion of the surface of the glass plate. By forming a dark-colored coating with low visible light transmittance on the surface of the glass plate, the visible light transmittance of the area where the coating is formed can be reduced. Therefore, by controlling the position where the coating is formed and the visible light transmittance of the coating, it is possible to provide the back window with a privacy area with a low visible light transmittance of 10% or less and an information acquisition area with a high visible light transmittance of 25% or more. As a result, privacy within the vehicle and visibility of the information acquisition device can be ensured.

[0009] In this specification, the visible light transmittance means the visible light transmittance measured by the method specified in JIS R3212:2015.

[0010] In the vehicle rear information acquisition system of the present disclosure, the glass plate may be gray glass with a visible light transmittance of 25% to 40%. If the purpose is to check information from outside the vehicle using an information acquisition device such as a camera, an image seen through the gray glass is sufficient. Furthermore, by using gray glass, the visible light transmittance of the privacy area can be reduced to 10% or less without forming an excessively dark coating.

[0011] In the vehicle rear information acquisition system of the present disclosure, the glass plate may be clear glass or green glass with a visible light transmittance of 70% or more and 95% or less. Using clear glass or green glass allows for a clearer image to be obtained than when gray glass is used. For example, an image viewed through gray glass may result in a color misrecognition, such as orange being recognized as red. In contrast, using an image viewed through clear glass or green glass can prevent color misrecognition. Therefore, if the purpose is not simply to check information from outside the vehicle but to perform various processes based on information from outside the vehicle, it is preferable to use clear glass or green glass.

[0012] In the vehicle rear information acquisition system of the present disclosure, it is preferable that no coating is provided on the surface of the glass sheet in the information acquisition area. In this case, by using a glass sheet with a visible light transmittance of 25% or more and forming a dark-colored coating only in the privacy area, the visible light transmittance of the privacy area can be set to 10% or less and the visible light transmittance of the information acquisition area can be set to 25% or more.

[0013] In the vehicle rear information acquisition system of the present disclosure, the coating may contain at least one of an infrared absorbing agent and an ultraviolet absorbing agent, thereby imparting at least one of an infrared absorbing function and an ultraviolet absorbing function to the back window.

[0014] In the vehicle rear information acquisition system of the present disclosure, it is preferable that the infrared transmittance of the privacy area is 15% or less and the infrared transmittance of the information acquisition area is 25% or more. For example, when an infrared camera is used as the information acquisition device, the visibility of the infrared camera can be ensured while ensuring infrared shielding.

[0015] In this specification, the infrared transmittance means the average transmittance at wavelengths of 780 nm to 2500 nm. [Effects of the Invention]

[0016] According to the present disclosure, privacy within the vehicle and visibility of the information acquisition device can be ensured. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is an enlarged cross-sectional view schematically illustrating an example of a vehicle rear information acquisition system according to the present disclosure. [Figure 2] FIG. 2 is a front view schematically illustrating an example of a back window constituting the vehicle rear information acquisition system of the present disclosure. [Figure 3] FIG. 3 is a front view schematically showing another example of a back window constituting the vehicle rear information acquisition system of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] The vehicle rear information acquisition system of the present disclosure will be specifically described below. However, the present disclosure is not limited to the following embodiments, and can be modified and applied as appropriate within the scope that does not change the gist of the present disclosure.

[0019] The vehicle rear information acquisition system of the present disclosure includes a back window attached to the rear of the vehicle, and an information acquisition device that is positioned inside the vehicle facing the back window and acquires information from outside the vehicle by irradiating and / or receiving light.

[0020] Fig. 1 is an enlarged cross-sectional view schematically illustrating an example of a vehicle rear information acquisition system according to the present disclosure, and Fig. 2 is a front view schematically illustrating an example of a back window constituting the vehicle rear information acquisition system according to the present disclosure.

[0021] The vehicle rear information acquisition system 1 shown in FIG. 1 includes a back window 10 attached to the rear of the vehicle, and an information acquisition device 20 arranged inside the vehicle so as to face the back window 10.

[0022] The information acquisition device 20 is a device that acquires information from outside the vehicle by emitting and / or receiving light, and is, for example, an imaging device such as a camera that captures the situation outside the vehicle. The information acquisition device 20 is disposed close to the back window 10, and is fixed to the back window 10 by an attachment member (not shown) as necessary.

[0023] The rear window 10 includes a glass sheet 11 and a coating 12 provided on the surface of the glass sheet 11. In FIG. 1, the coating 12 is provided on the surface of the glass sheet 11 facing the interior of the vehicle.

[0024] As shown in FIGS. 1 and 2, the back window 10 has a privacy area R1 for protecting privacy inside the vehicle, and an information acquisition area R2 facing the information acquisition device 20 and through which light passes.

[0025] In the privacy area R1, a coating 12 is provided on the surface of the glass plate 11. As a result, the visible light transmittance of the privacy area R1 is 10% or less.

[0026] On the other hand, the visible light transmittance of the information acquisition region R2 is 25% or more. In Fig. 1, the coating 12 is not provided on the surface of the glass plate 11 in the information acquisition region R2.

[0027] 2, a light-shielding layer 13 is preferably provided on the peripheral edge of the back window 10. Furthermore, the back window 10 may be provided with a heating wire (defogger) 14 and an antenna 15.

[0028] In the vehicle rear information acquisition system disclosed herein, a coating is provided on the surface of the glass plate in the privacy area, and the visible light transmittance of the privacy area is 10% or less, while the visible light transmittance of the information acquisition area is 25% or more.

[0029] As described above, by controlling the position where the coating is formed, the visible light transmittance of the coating, etc., it is possible to provide a privacy area with a low visible light transmittance of 10% or less and an information acquisition area with a high visible light transmittance of 25% or more on the back window. As a result, privacy within the vehicle and visibility of the information acquisition device can be ensured.

[0030] In the vehicle rear information acquisition system of the present disclosure, a coating may be provided on the surface of the glass sheet in the information acquisition area as long as the visible light transmittance of the information acquisition area is 25% or more, but it is preferable that no coating is provided on the surface of the glass sheet. By using a glass sheet with a visible light transmittance of 25% or more and forming a dark coating only in the privacy area, the visible light transmittance of the privacy area can be set to 10% or less and the visible light transmittance of the information acquisition area can be set to 25% or more.

[0031] In the vehicle rear information acquisition system disclosed herein, the shape, number, position, etc. of the information acquisition area provided on the rear window are not particularly limited, and are set appropriately depending on the shape and number of information acquisition devices to be placed inside the vehicle, the positions at which the information acquisition devices are placed, etc.

[0032] FIG. 3 is a front view schematically showing another example of a back window constituting the vehicle rear information acquisition system of the present disclosure. The back window 10A shown in Figure 3 has a privacy area R1 for protecting privacy inside the vehicle, an information acquisition area R2 facing the information acquisition device 20 and through which light passes, and a light transmission area R3 through which light from warning lights such as high-mounted stop lamps passes.

[0033] The back window 10A has information acquisition regions R2 at two locations, one on the upper side and one on the lower side in the height direction. The lower information acquisition region R2 is located approximately in the center in the width direction. The upper information acquisition region R2 is located adjacent to the light transmission region R3. The light transmission region R3 is located on the upper side in the height direction and approximately in the center in the width direction.

[0034] The visible light transmittance of the light transmitting region R3 is preferably 25% or more. In Fig. 3, the coating 12 is not provided on the surface of the glass plate 11 in the light transmitting region R3. Although not shown, a warning light such as a high-mounted stop lamp is arranged inside the vehicle so as to face the back window 10A.

[0035] A light-shielding layer 13 is provided on the periphery of the back window 10A shown in Fig. 3. In addition, a heating element (defogger) 14, an antenna 15, and wipers 16 are provided on the back window 10A.

[0036] In the vehicle rear information acquisition system of the present disclosure, the information acquisition device is not particularly limited as long as it emits and / or receives light to acquire information from outside the vehicle. Examples of the information acquisition device include a camera (visible light camera, infrared camera, stereo camera, etc.), a sensor (line sensor, rain sensor, etc.), a laser radar, an optical beacon, etc. The number of information acquisition devices arranged inside the vehicle may be one or two or more. Furthermore, the location where the information acquisition device is arranged is not particularly limited.

[0037] The vehicle rear information acquisition system of the present disclosure preferably further includes an information processing device connected to the information acquisition device. The information processing device processes information acquired by the information acquisition device, for example, a device for processing captured images acquired by an imaging device such as a camera.

[0038] The processing of information such as captured images can be selected as appropriate. For example, the captured image may be analyzed using pattern matching or the like to recognize the subject appearing in the captured image. Furthermore, based on the subject recognition, it may be determined whether a living thing such as a human is present behind the vehicle. If a living thing is present behind the vehicle, a warning may be output using a predetermined method. Furthermore, for example, the captured image may be subjected to a predetermined processing process. The processed captured image may then be output to a display device such as a display connected to the information processing device.

[0039] In the vehicle rear information acquisition system of the present disclosure, the glass sheet that constitutes the back window is a glass sheet that is typically used as glass for vehicles such as automobiles.

[0040] In the vehicle rear information acquisition system of the present disclosure, the glass plate may be gray glass with a visible light transmittance of 25% to 40%. If the purpose is to check information from outside the vehicle using an information acquisition device such as a camera, an image seen through the gray glass is sufficient. Furthermore, by using gray glass, the visible light transmittance of the privacy area can be reduced to 10% or less without forming an excessively dark coating.

[0041] Such gray glass has a thickness of 3.1 mm or less, is made of soda-lime glass containing iron oxide, has a total iron oxide (T-Fe2O3) content calculated as Fe2O3 of 0.9 to 2.2 wt%, and is colored by one or more of Se, CoO, Nd2O3, NiO, MnO2, V2O5, CeO2, TiO2, CuO, Cr2O3, and SnO.

[0042] In the vehicle rear information acquisition system of the present disclosure, the glass plate may be clear glass or green glass (also referred to as green glass) with a visible light transmittance of 70% or more and 95% or less. Using clear glass or green glass allows for a clearer image to be obtained than when gray glass is used. For example, an image viewed through gray glass may result in a color misrecognition, such as orange being recognized as red. In contrast, using an image viewed through clear glass or green glass can prevent color misrecognition. Therefore, if the purpose is not simply to check information from outside the vehicle but to perform various processes based on information from outside the vehicle, it is preferable to use clear glass or green glass.

[0043] In the vehicle rear information acquisition system of the present disclosure, the coating constituting the rear window may contain at least one of an infrared absorbing agent and an ultraviolet absorbing agent, thereby imparting at least one of an infrared absorbing function and an ultraviolet absorbing function to the rear window.

[0044] In the vehicle rear information acquisition system of the present disclosure, it is preferable that the infrared transmittance of the privacy area is 15% or less and the infrared transmittance of the information acquisition area is 25% or more. For example, when an infrared camera is used as the information acquisition device, the visibility of the infrared camera can be ensured while ensuring infrared shielding.

[0045] In the vehicle rear information acquisition system of the present disclosure, the coating that constitutes the back window can be formed, for example, by applying a black coating-forming coating liquid containing a black pigment (carbon black, manganese ferrite, titanium black, etc.) to the surface of a glass plate to form a coating film, and then heating the glass plate to harden the coating film.

[0046] The composition of the coating liquid for forming the black coating film is not particularly limited, but as an example, the composition using a silane compound containing an amino group is shown below.

[0047] For example, a method for producing a black-coated glass sheet comprising a glass sheet and a black coating formed on at least one surface of the glass sheet has the following features. (a)R 1 4-n Si(OR 2 ) n A silane compound containing an amino group represented by formula [1] (wherein R 1 represents an organic group containing an amino group, and R 2 represents a methyl group, an ethyl group, or a propyl group, and n represents an integer selected from 1 to 3), at least one boron compound selected from the group consisting of H3BO3 and B2O3; a reaction product obtained by reacting (b) metal alkoxides and / or metal alkoxide condensates; (c) synthetic resin; (d) SP value is 8 to 11.5 (cal / cm 3 ) 1 / 2 a solvent comprising a non-aqueous solvent in which (e) a black pigment; and a step of mixing the black pigment to obtain a coating solution for forming a black coating film. a coating step of applying the black coating film-forming coating liquid to the surface of the glass plate to form a coating film; a curing step of heating the glass plate after the coating step to harden the coating film to form a black coating film, The coating liquid for forming a black coating film contains the black pigment in an amount of 0.5 to 7.0% by mass based on the total solid content.

[0048] "Total solids content" refers to the total amount of components constituting the black coating, and this amount can be determined by subtracting the amount of organic groups released from each component by hydrolysis, polycondensation reaction, etc. from the sum of the components excluding the solvent from the coating liquid for forming a black coating. Furthermore, the viscosity of the coating liquid for forming a black coating is also affected by the amount of total solids in the coating liquid for forming a black coating, and can be set in consideration of the efficiency of application of the coating liquid for forming a black coating to the glass plate; for example, the amount of total solids can be set to 5% by mass to 40% by mass, preferably 10% by mass to 35% by mass.

[0049] The composition of the coating solution for forming a black coating film may be a composition using 3-glycidoxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS), in which case the coating solution for forming a black coating film can be prepared by adding the above component (e) and water to GPTMS and TEOS.

[0050] 1.(a) Component R 1 4-n Si(OR 2 ) n [1] Silane compounds containing amino groups (In formula [1], R 1 represents an organic group containing an amino group, and R 2represents a methyl group, 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 H3BO3 and BO3, these components react and become a transparent, viscous liquid within a few minutes to a few tens of minutes, which then solidifies. This is thought to be because the boron compound acts as a crosslinker via the amino groups in the amino-containing silane compound, polymerizing these components. As a result, the viscous liquid solidifies. Note that the amino-containing silane compound is a liquid. It is preferable not to use water when reacting the amino-containing silane compound with the boron compound.

[0051] In the above silane compound containing an amino group, R 1 represents an amino group-containing organic group. Examples include, but are not limited to, monoaminomethyl, diaminomethyl, triaminomethyl, monoaminoethyl, diaminoethyl, triaminoethyl, tetraaminoethyl, monoaminopropyl, diaminopropyl, triaminopropyl, tetraaminopropyl, monoaminobutyl, diaminobutyl, triaminobutyl, tetraaminobutyl, and organic groups having an alkyl group or aryl group with a carbon number greater than these. γ-Aminopropyl or aminoethylaminopropyl is particularly preferred, and γ-aminopropyl is most preferred.

[0052] Above R 2 represents a methyl group, an ethyl group, or a propyl group. Among these, a methyl group or an ethyl group is preferred. The above n represents an integer selected from 1 to 3. Among these, n is preferably 2 to 3, and n is particularly preferably 3. That is, as the silane compound containing the amino group, γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane are particularly preferred.

[0053] The boron compound is at least one boron compound selected from the group consisting of H3BO3 and B2O3, and is particularly preferably H3BO3.

[0054] In consideration of the reaction rate, the amounts of the amino group-containing silane compound and the boron compound used in the reaction are preferably 0.02 to 8 moles, more preferably 0.02 to 5 moles, and even more preferably 0.2 to 5 moles of the boron compound per mole of the amino group-containing silane compound.

[0055] The mixing conditions (temperature, mixing time, mixing method, etc.) of the silane compound containing an amino group and the boron compound can be selected appropriately. Under normal room temperature conditions, the mixture becomes a transparent, viscous liquid and solidifies within several 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 boron compound. Note that a viscous liquid is preferable to a solidified product because it is easier to form a stably dissolved component in the coating liquid. The reaction product is preferably a reaction product obtained by reacting the silane compound containing an amino group with the boron compound without going through a hydrolysis step involving the addition of water.

[0056] The amount of the reaction product can be 40% by mass to 80% by mass based on the total solid content. If the amount is less than 40% by mass, the hardness of the resulting black coating may be low. On the other hand, if the amount is more than 80% by mass, the resulting black coating may crack during a weather resistance test. Taking these factors into consideration, the amount of the reaction product may be 50% by mass to 70% by mass based on the total solid content.

[0057] 2.(b) Component To the reaction product, a metal alkoxide and / or a condensate of a metal alkoxide is added as component (b). That is, component (b) is added during or after the reaction between the silane compound containing an amino group and the boron compound. Adding component (b) not only improves the hardness of the resulting black coating, but also results in a viscous liquid state similar to that obtained without component (b), making it possible to obtain a component that is stably dissolved in the coating solution.

[0058] Examples of metals in the metal alkoxide of component (b) include, but are not limited to, Si, Ta, Nb, Ti, Zr, Al, Ge, B, Na, Ga, Ce, V, Ta, P, and Sb. Si, Ti, and Zr are preferred, and since component (b) is preferably a liquid, Si and Ti are particularly preferred. Examples of the alkoxide (alkoxy group) in the metal alkoxide of component (b) include methoxy, ethoxy, propoxy, butoxy, and alkoxy groups having a carbon number greater than or equal to 1. Methoxy, ethoxy, propoxy, and butoxy are preferred, with methoxy and ethoxy being more preferred. Particularly preferred examples of component (b) include tetramethoxysilane and tetraethoxysilane.

[0059] Specific examples of the metal alkoxide of component (b) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, propyltrippropoxysilane, butyltributoxysilane, tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, methyltrimethoxytitanium, ethyltriethoxytitanium, propyltrippropoxytitanium, butyltributoxytitanium, tetramethoxyzirconium, tetraethoxyzirconium, tetrapropoxyzirconium, tetrabutoxyzirconium, methyltrimethoxyzirconium, ethyltriethoxyzirconium, propyltrippropoxyzirconium, and butyltributoxyzirconium. Among these, preferred are tetraethoxysilane, tetramethoxysilane, ethyltriethoxysilane, and methyltrimethoxysilane.

[0060] The amount of metal alkoxide used as component (b) is preferably 10 moles or less per mole of the silane compound containing an amino group, and more preferably 0.1 to 5 moles. If the amount of component (b) is less than 0.1 mole per mole of the silane compound containing an amino group and the boron compound, the aforementioned effect of adding component (b) may be difficult to obtain, and if the amount of component (b) is more than 5 moles, the solution may become cloudy.

[0061] The metal alkoxide condensate of component (b) can be a metal alkoxide condensate represented by at least one formula selected from the group consisting of the following formulae (b1) and (b2).

[0062] [ka]

[0063] [ka]

[0064] (In the formula, R 3 represents an alkyl group, some of which may be hydrogen, and R 3 may be independently the same or different, m represents an integer selected from 2 to 20, and M represents at least one metal selected from the group consisting of Si, Ti, and Zr.

[0065] The amount of the metal alkoxide condensate (component (b)) added is preferably 2 to 50 moles, more preferably 4 moles or more, calculated as the mass of the metal alkoxide monomer per mole of the amino group-containing silane compound. That is, if the amount of component (b) added is too large, the hardness of the resulting coating tends to decrease. Conversely, if the amount is too small, the metal element content will be low, which may result in a decrease in the hardness of the resulting coating or problems with chemical durability depending on the application. Furthermore, if the amount of component (b) added is too large, the curing time required to obtain a black coating tends to be long.

[0066] R in the condensate of the metal alkoxide, which is the component (b), 3 represents an alkyl group, some of which may be hydrogen, and R 3 may be the same or different, but R 3 is a methyl group, ethyl group, propyl group, butyl group, or an alkyl group having a carbon number of 1 or more, and is preferably a methyl group or an ethyl group. Furthermore, m in the metal alkoxide condensate of 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 of component (b) represents at least one metal selected from the group consisting of Si, Ti, and Zr, and is preferably Si or Ti, and most preferably Si.

[0067] Examples of the metal alkoxide monomer units constituting the metal alkoxide condensate, component (b), include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, ethyltriethoxysilane, propyltrippropoxysilane, butyltributoxysilane, tetramethoxytitanium, tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, methyltrimethoxytitanium, ethyltriethoxytitanium, propyltrippropoxytitanium, butyltributoxytitanium, tetramethoxyzirconium, tetraethoxyzirconium, tetrapropoxyzirconium, tetrabutoxyzirconium, methyltrimethoxyzirconium, ethyltriethoxyzirconium, propyltrippropoxyzirconium, and butyltributoxyzirconium.

[0068] When the component (b) is represented by the above formula (b1), it is preferably a tetraethoxysilane condensate (pentamer) or a tetramethoxysilane condensate (pentamer), and when it is represented by the above formula (b2), it is preferably a ethyltriethoxysilane condensate (pentamer) or a methyltrimethoxysilane condensate (pentamer).

[0069] As described above, a metal alkoxide (monomer) and / or a condensate of a metal alkoxide is added to the reaction product as component (b). Because the viscosity of a metal alkoxide monomer is lower than that of the condensate, the application properties of the resulting coating solution may be improved by further adding the metal alkoxide monomer. However, if the amount of the metal alkoxide monomer added is greater than or equal to the amount of the condensate, the viscosity of the coating solution may decrease, and dripping may occur during application.

[0070] 3.(c) Component A synthetic resin is added as component (c) to the reaction product. That is, the synthetic resin is added as component (c) during or after the reaction between the silane compound containing an amino group and the boron compound. Adding component (c) can impart crack prevention properties to the resulting black coating.

[0071] The synthetic resin of component (c) is not particularly limited, but examples thereof include thermosetting resins, thermoplastic resins, and ultraviolet-curable resins. Specific examples include acrylic resins, epoxy resins, polyester resins, amino resins, urethane resins, furan resins, silicone resins, and modified versions of these resins. Synthetic resins with various degrees of polymerization (molecular weights) can be used. Among these, epoxy resins, dipentaerythritol hexaacrylate, epoxy acrylate, silicone resins, vinyl ester resins, polyvinyl butyral, polyvinyl alcohol, and the like are preferred. Furthermore, the synthetic resin is preferably in liquid form.

[0072] The amount of component (c) used is preferably 5 to 30% by mass relative to the total solid content, and more preferably 10 to 20% by mass. If the amount of component (c) is less than 5% by mass, the aforementioned effects of adding component (c) may be difficult to obtain. If the amount of component (c) is more than 30% by mass, a resin curing agent may need to be added, and the resulting coating may not have sufficient hardness.

[0073] 4.(d) Component Component (d) is a solvent for the coating solution for forming a black film, and has a substantial SP value of 8 to 11.5 (cal / cm 3 ) 1 / 2 The non-aqueous solvent has a SP value of 8 to 11.5 (cal / cm 3 ) 1 / 2 "A non-aqueous solvent having an SP value of 8 to 11.5 (cal / cm 3 ) 1 / 2 "A single-type non-aqueous solvent with an SP value of 8 to 11.5 (cal / cm 3 ) 1 / 2 The SP value of the mixed solvent is 8 to 11.5 (cal / cm 3 ) 1 / 2 "Solvents with SP values ​​between 8 and 11.5 (cal / cm 3 ) 1 / 2 The SP value of the mixed solvent is 8 to 11.5 (cal / cm 3 ) 1 / 2 The SP value of a mixed solvent can be calculated using the following formula, for example, when two types of solvent, "solvent A" and "solvent B," are used.

[0074]

number

[0075] The SP value is a commonly known solubility parameter that serves as an index of solubility and compatibility. Known methods for calculating the SP value include the heat of vaporization of the liquid, the Hansen method, the Hoy method, the Small method, and the Fedor estimation method, which are methods that calculate based on molecular structure. In this specification, the Fedor estimation method, which calculates based on molecular structure, as described in, for example, R.F. Fedors: Polym. Eng. Sci., 14(2), 147-154 (1974), is used. The SP value in this specification is a value determined under measurement conditions at 25°C.

[0076] SP value is 8 to 11.5 (cal / cm3 ) 1 / 2 Examples of non-aqueous solvents with this property include toluene (SP value: 9.1 (cal / cm 3 ) 1 / 2 ), xylene (SP value: 9.1 (cal / cm 3 ) 1 / 2 ), ethyl acetate of acetate esters (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-methoxybutyl 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 ), cellosolve ethylene glycol monoethyl ether (SP value: 11.5 (cal / cm 3 ) 1 / 2 ), ethylene glycol mono-normal butyl ether (SP value: 10.8 (cal / cm3 ) 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 N,N-dimethylformamide (SP value: 10.2 (cal / cm 3 ) 1 / 2 ), and among them, 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 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 ) is preferred.

[0077] In addition, the SP value that may be contained in the coating solution is 8 to 11.5 (cal / cm 3 ) 1 / 2 Examples of solvents other than hexane include 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 ), carbon tetrachloride (SP value: 12.2 (cal / cm 3 ) 1 / 2 ) etc.

[0078] 5.(e) Ingredient Examples of the black pigment (e) include Pigment Black 26, carbon black, and titanium black. The average particle diameter D of the black pigment is 50 is preferably 10 to 300 nm. 50 If the average particle diameter D of the black pigment is less than 10 nm, the pigment tends to aggregate easily, and if it exceeds 300 nm, the visible light transmittance tends to deteriorate. 50 The thickness is more preferably 15 to 280 nm, and further preferably 20 to 250 nm.

[0079] The black pigment is preferably contained in the coating solution for forming a black film in an amount of 0.5 to 7.0 mass% based on the total solid content. If it is less than 0.5 mass%, privacy tends to be poor, and if it exceeds 7.0 mass%, haze tends to be high. In consideration of these, the black pigment is more preferably contained in the coating solution for forming a black film in an amount of 0.6 to 6.5 mass%, and even more preferably 0.7 to 6.0 mass%, based on the total solid content.

[0080] 6. Other Ingredients The coating liquid for forming the black coating film may contain fine particles made of a conductive material. By containing fine particles made of a conductive material, infrared shielding properties can be imparted to the black coated glass sheet. Examples of the conductive material include ITO (indium tin oxide) and ATO (antimony tin oxide). The content of the fine particles made of a conductive material is preferably 5 to 15 mass % based on the total solid content, and the average particle diameter D 50 It is preferable that the thickness is 50 to 100 nm.

[0081] In addition to the above components, the coating liquid for forming a black coating may also contain, depending on its intended use, an ultraviolet absorber, a coloring pigment, an antifungal agent, a photocatalytic material, an antirust agent, an anticorrosion agent, an anti-algae agent, a water repellent, an oil repellent, a light stabilizer, an antioxidant, a substrate wetting agent, a hydrophilic material, a water-absorbing material, and the like.

[0082] The coating liquid for forming a black coating film can be applied to the surface of a glass plate by known coating methods such as spin coating, dip coating, nozzle coating, curtain coating, roll coating, spray coating, blade coating, brush coating, etc. Among these, spray coating is preferred because it is not dependent on the shape of the glass to be coated and can form a film with a small amount of coating liquid.

[0083] It is preferable not to form a black coating on the surface of the plate glass that will become the information acquisition area. For example, the coating liquid may be applied to the entire surface of the substrate (plate glass) once, and the coating liquid may be wiped off from the area where the coating is not to be formed, or the area where the coating is not to be formed may be immersed in a solvent to remove the coating liquid applied to that area, or a solvent may be poured over the area where the coating is not to be formed to remove the coating liquid applied to that area, or the area where the coating is not to be formed may be masked in advance, and the masking may be removed after coating. For example, masking tape, metal masking, etc. may be used as the masking.

[0084] Alternatively, a water-repellent film or a water- and oil-repellent film that repels the coating liquid (is incompatible with the coating liquid) may be formed in advance in an area where no coating is to be formed, and then the coating liquid may be applied, and the coating liquid that is repelled by the water-repellent film or the water- and oil-repellent film and adheres to the surface may be wiped off.Furthermore, the water-repellent film or the water- and oil-repellent film may also be removed.

[0085] Alternatively, a water-repellent film or a water- and oil-repellent film that repels the coating liquid (is incompatible with the coating liquid) may be formed in advance in an area where the coating is not to be formed, and then the coating may be applied and cured, and the cured coating that has been repelled by the water-repellent film or the water- and oil-repellent film may be removed.Furthermore, the water-repellent film or the water- and oil-repellent film may also be removed.

[0086] Alternatively, the composition may be applied to the entire surface of the substrate (plate glass), cured, and then a coating may be formed on the entire surface of the substrate (plate glass), and then desired areas of the coating may be physically or chemically removed.

[0087] In the vehicle rear information acquisition system of the present disclosure, the coating that constitutes the back window preferably has a thickness of 1 μm to 8.5 μm. If the coating thickness is less than 1 μm or more than 8.5 μm, the durability of the coating tends to deteriorate.

[0088] The thickness of the coating can be measured using a surface roughness measuring device (for example, Surfcorder ET4000A manufactured by Kosaka Laboratory).

[0089] The vehicle rear information acquisition system of the present disclosure is not limited to the above-described embodiment, and various applications and modifications can be made within the scope of the present disclosure with respect to the configuration and manufacturing method of the glass sheet, the configuration and forming method of the coating, and the configuration of the information acquisition device.

[0090] This application claims priority under the Paris Convention or the laws of countries that have adopted it, based on Japanese Patent Application No. 2019-159667 filed on September 2, 2019. The contents of that application are incorporated herein by reference in their entirety. [Explanation of symbols]

[0091] 1. Vehicle rear information acquisition system 10, 10A Back window 11 Plate Glass 12 Coating 13 Light blocking layer 14 Heat wire 15 Antenna 16. Wiper 20 Information acquisition device R1 Privacy Area R2 Information acquisition area R3 Light transmission area

Claims

1. A back window attached to the rear of the vehicle; a vehicle rear information acquisition system including an information acquisition device that is disposed inside the vehicle so as to face the back window and that acquires information from outside the vehicle by irradiating and receiving light or by receiving light, the rear window includes a glass sheet and a coating provided on at least a portion of a surface of the glass sheet, and has a privacy area for protecting privacy inside the vehicle, and an information acquisition area facing the information acquisition device and through which the light passes, The plate glass is gray glass having a visible light transmittance of 25% or more and 40% or less, The privacy area has the coating on the surface of the glass pane; The privacy area has a visible light transmittance of 10% or less; A vehicle rear information acquisition system, wherein the visible light transmittance of the information acquisition area is 25% or more.

2. The vehicle rear information acquisition system according to claim 1 , wherein the coating is not provided on the surface of the glass plate in the information acquisition area.

3. The vehicle rearward information acquisition system according to claim 1 or 2, wherein the coating contains at least one of an infrared absorbing agent and an ultraviolet absorbing agent.

4. The privacy area has an infrared transmittance of 15% or less; 4. The vehicle rear information acquisition system according to claim 1, wherein the information acquisition area has an infrared transmittance of 25% or more.

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