DE112019004506T5 - Glass and laminated glass - Google Patents

Abstract

The object of the present invention is to improve the response speed of a light control element in a glass having the light control element at a low temperature. The glass of the present invention is a glass for a vehicle and comprises a glass plate; a transparent area defined in the glass; and a light control element that is disposed in at least a portion of an area of the glass plate that overlaps the transparent area in plan view, and that is configured to switch the light transmission, the light control element having a light control layer; a pair of conductive thin films surrounding the light control layer; a pair of light control busses configured to supply power to the pair of conductive thin films so that the light control layer is operated; and a pair of heating bus bars configured to heat at least one of the pair of conductive thin films.

Description

[Technical area]

The present invention relates to a glass and a laminated glass.

[State of the art]

For safety reasons, a vehicle has a transparent area made of glass and, for example, an occupant can see circumstances outside the vehicle. Further, in recent years, for the purpose of improving the safety of vehicles, vehicles having functions of automatically avoiding collision with another vehicle ahead or a pedestrian have been developed. Such a vehicle has, for example, a device such as a camera installed in the vehicle, and sends and receives information such as road conditions through the glass (e.g. the windshield or the like) of the vehicle.

In some cases, however, it becomes difficult to obtain information through the transparent area from outside the vehicle due to backlighting from sunlight or headlights from oncoming vehicles. Accordingly, in some cases, it becomes difficult for the device such as a camera to obtain information from outside the vehicle due to backlighting by sunlight or headlights from oncoming vehicles. Therefore, there has been proposed a technique using a liquid crystal panel which can change the light transmittance for each of a plurality of divided areas, i.e., can control light. In this technique, anti-glare performance is achieved by averaging the amount of incident light generated between areas in a backlight or the like by a light controller so that the brightness of the entire image of the device such as a camera is equalized (See, for example, Patent Document 1).

[Prior art documents]

[Patent documents]

Patent Document 1: Japanese Unexamined Patent Application Publication Number H9-214827

[Summary of the invention]

[Problem to be Solved by the Invention]

However, when a light control element is applied to the glass of a vehicle, the response speed of the light control element decreases at a low temperature (for example, around -20 ° C); therefore, an anti-glare property which may be required cannot be achieved at the low temperature.

The present invention has been made in view of the above points and has an object to improve the response speed of a light control element in a glass having the light control element at a low temperature.

[Means of solving the problems]

The present glass is a glass for a vehicle and includes a glass plate; a transparent area defined in the glass; and a light control element that is disposed in at least a portion of an area of the glass plate that overlaps the transparent area in plan view, and that is configured to switch the light transmission, the light control element having a light control layer; a pair of conductive thin films surrounding the light control layer; a pair of light control busses configured to supply power to the pair of conductive thin films so that the light control layer is operated; and a pair of heating bus bars configured to heat at least one of the pair of conductive thin films.

[Effects of the invention]

According to an embodiment of the present disclosure, the response speed of a light control element in a glass including the light control element can be improved at a low temperature.

Figure list

• 1 includes diagrams showing an example of a windshield for a vehicle according to a first embodiment;
• 2 includes diagrams showing an example of a light control element according to the first embodiment;
• 3 Fig. 13 is a plan view showing an example of a light control member according to Modified Example 1 of the first embodiment;
• 4th Fig. 13 is a cross-sectional view showing an example of a light control member according to Modified Example 2 of the first embodiment;
• 5 Fig. 13 is a diagram showing a cross-sectional structure of a laminated glass according to a comparative example; and
• 6th Fig. 13 is a diagram showing conditions and results of Examples and Comparative Examples.

[Mode for carrying out the invention]

Embodiments for carrying out the invention will be described below with reference to the drawings. In the drawings, the same elements are assigned the same reference numerals and duplicate descriptions may be omitted. Further, in some of the drawings, the size and shape may be partially exaggerated in order to facilitate understanding of the disclosure of the present invention.

It should be noted that although a windshield for a vehicle is used as an example for the description, the application is not limited thereto; a glass according to the embodiments can be applied to a glass other than a windshield for a vehicle. Further, although, as the transparent area, an information transmission / reception area is used as an example for the description, it is not limited as such; the transparent area refers to an area in the glass through which light can pass and circumstances outside the vehicle can be recognized. Furthermore, a vehicle is typically a motor vehicle or automobile, but generally refers to a mobile body with a glass which comprises a rail vehicle or train, a watercraft or a ship or boat, an aircraft or airplane and the like.

Further, “plan view” refers to viewing a given area of a windshield in the perpendicular direction of the given area, and “planar shape” refers to a shape of the given area of the windshield when viewed in the perpendicular direction of the given area. Further, in the description of the present application, above and below refer to the Z-axis direction of a drawing, and left and right refer to the Y-axis direction of a drawing.

Further, the visible light transmittance in the present invention corresponds to a value specified in JIS R3108: 1998.

Further, the energy reflectance in the present invention corresponds to a value specified in JIS R3108: 1998.

<First embodiment>

The 1 includes diagrams exemplifying a windshield for a vehicle according to a first embodiment, wherein FIG 1 (a) Fig. 13 is a diagram schematically showing how a windshield is visually perceived from the inside of the vehicle to the outside of the vehicle (the windshield 20th is in a state of being attached to the vehicle upward in the Z direction); and the 1 (b) Fig. 3 is a cross-sectional view of the windshield 20th that are in the 1 (a) is shown cut in the XZ direction and viewed in the Y direction. It should be noted that in the 1 (b) although device 300 is included with the windshield for convenience 20th As shown, the device 300 is not an element of the windshield 20th is.

Like it in the 1 shown is the windshield 20th a laminated glass for a vehicle that has a sheet of glass 21 as a glass plate on the inside of the vehicle; a glass plate 22nd as a glass plate on the outside of the vehicle; an intermediate layer 23 ; a shading layer 24 ; and a light control element 25th includes.

In the windshield 20th are the glass plate 21 and the glass plate 22nd connected or glued together, the intermediate layer 23 and the light control element 25th are arranged in between. The intermediate layer 23 may be formed from a plurality of layers of intermediate layers. The glass plate 21 who have favourited glass plate 22nd and the intermediate layer 23 will be described in more detail later.

The shading layer 24 is on the edge of a surface 21a the glass plate 21 provided on the inside of the vehicle. The shading layer 24 is an opaque layer and can be formed, for example, by applying a printing ink with a predetermined color to a glass surface. The shading layer 24 is for example an opaque, colored (e.g. black) ceramic layer. The presence of the opaque shading layer 24 on the edge of the windshield 20th may involve breaking down members including an adhesive member such as urethane for holding the edge portion of the windshield 20th to be attached to the vehicle body, an adhesive member for attaching a bracket that attaches the device 300 to the Windshield 20th and the like due to ultraviolet light.

It should be noted that in the 1 (b) although the shading layer 24 on the surface 21a the glass plate 21 is provided on the inside of the vehicle, it is not limited as such. The shading layer 24 can for example on a surface of the glass plate 22nd may be provided on the inside of the vehicle, or both on the surface 21a the glass plate 21 on the inside of the vehicle as well as the surface of the glass plate 22nd be provided on the inside of the vehicle.

The windshield 20th has a demarcated test area A specified in JIS standard R3212. Furthermore, the windshield 20th a transparent area, here a delimited information transmission / reception area 26. The test area A is positioned within an area which, in plan view, is through the shading layer 24 is surrounded, and the information broadcast receiving area 26th is positioned within an opening made in the shading layer 24 is provided.

The information broadcast reception area 26th acts as an area through which the device 300 sends and / or receives information in the case where the device 300 is placed on the upper edge portion or the like of the windshield 20th is arranged in the vehicle. The planar shape of the information transmission / reception area 26 is not particularly limited and may be, for example, an isosceles trapezoid. It is preferable that the information transmission / reception area 26 does not interfere with the driver's field of view when the windshield is used 20th is attached to the vehicle, and it is positioned at the same time above the test area A, since this is advantageous with regard to the sending and / or receiving of information.

It should be noted that device 300 is a device for transmitting and / or receiving information, such as a camera receiving visible light and infrared light, millimeter wave radar, infrared laser, or the like, and is typically a camera. In addition to the device 300, a further device for sending and / or receiving information through the information sending / receiving area 26 can be arranged in the vehicle. Here, a "signal" refers to an electromagnetic wave, including millimeter waves and light such as visible light, infrared light, and the like, and is typically visible light.

The light control element 25th is an element disposed over at least a portion of an area outside the test area A and the information broadcast receiving area 26th between the glass plate 21 and the glass plate 22nd overlaps in plan view, and can switch the light transmittance of the information sending / receiving area 26. The light control element 25th can depending on requirements within the test area A in the plan view between the glass plate 21 and the glass plate 22nd be arranged.

Although it is advantageous that the planar shape of the light control element 25th for example, is a rectangular shape slightly larger than the planar shape of the information broadcast receiving area 26th , it can be a trapezoidal shape, a rectangular shape or a trapezoidal shape with one or more curved sides or any other shape. The planar shape of the light control element 25th may be smaller than the planar shape of the information transmission / reception area 26.

The 2 includes diagrams showing an example of a light control element according to the first embodiment, FIG 2 (a) Fig. 13 is a plan view schematically showing how the vicinity of the information broadcast receiving area is visually perceived from the inside of the vehicle to the outside of the vehicle; and the 2 B) FIG. 3 is a cross-sectional view taken along line AA in FIG 2 (a) is. It should be noted that in the 2 (a) a representation of the glass plates 21 and 22nd , the intermediate layer 23 and the shading layer 24 is omitted. Furthermore, in the 2 (a) the information sending / receiving area 26 is indicated with dashed lines for convenience.

The light control element 25th is in the intermediate layer 23 included and comprises a base material 251 , a conductive thin film 252 , a light control layer 253 , a conductive thin film 254 , a base material 255 , Heating busbar 256 and lighting control busbars 257 .

As base materials 251 and 255 For example, a transparent resin or glass can be used. Although the thickness of the base materials 251 and 255 can be set to be larger than or equal to 5 μm and smaller than or equal to 500 μm, it is preferably larger than or equal to 10 μm and smaller than or equal to 200 μm and more preferably larger than or equal to 50 μm and smaller than or equal to 150 μm .

Plastic films used as the base materials 251 and 255 can serve from a homopolymer or a copolymer of at least one monomer, for example selected from a group comprising polyesters (e.g. polyethylene terephthalate, polyethylene naphthalate and the like), polyamide, polyether, polysulfone, polyethersulfone, polycarbonate, polyallylate, polyetherimide, polyetheretherketone, polyimide, aramid, polybutylene terephthalate, polyvinylbutyral and polyethylvinyl acetate. As glass materials, which are the base materials 251 and 255 can be mentioned, for example, soda lime glass, inorganic glass such as aluminosilicate, and organic glass and the like.

The conductive thin film 252 is on a surface of the base material 251 on the side of the glass plate 21 formed and contacted a surface of the light control layer 253 on the side of the glass plate 22nd . The conductive thin film 254 is on a surface of the base material 255 on the side of the glass plate 22nd formed and contacted a surface of the light control layer 253 on the side of the glass plate 21 . In other words, the conductive thin films 252 and 254 are a pair of conductive thin films that form the light control layer 253 surround.

As the conductive thin films 252 and 254 For example, a transparent conductive oxide (TCO) can be used. As the TCO, tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), indium-doped cadmium oxide and the like can be mentioned, although they are not limited thereto.

As the conductive thin films 252 and 254 For example, a transparent conductive polymer such as poly (3,4-ethylenedioxythiophene) (PEDOT) or poly (4,4-dioctylcyclopentadithiophene) can also be suitably used. Further, it can be used as the conductive thin films 252 and 254 a laminated film made of a metal layer and a dielectric layer, a silver nanowire, a metal mesh made of silver or copper, or the like can also be suitably used.

The conductive thin films 252 and 254 can be formed, for example, by means of sputtering, vacuum vapor deposition, physical vapor deposition (PVD) such as ion plating. The conductive thin films 252 and 254 can be formed using chemical vapor deposition (CVD) or wet coating.

It must also be used when using the light control element 25th on the windshield 20th prevent the light control 25th gets hot and degrades due to heat rays from the sun. To achieve this, the light control element, for example 25th can be used in conjunction with a heat ray reflective glass or a heat ray reflective film. In this case, it is advantageous to use a heat ray reflective film, the cost of which is relatively low, since applying heat ray reflective glass only to the vicinity of the information transmission / reception area 26 results in a high cost. However, when a heat ray reflective film is used, the addition of the heat ray reflective film lowers the transmittance of the windshield 20th and / or changes the color of the windshield 20th and thereby can impair the sensing capability of device 300.

By the windshield 20th can / can the conductive thin film 252 and / or the conductive thin film 254 that or those for supplying power to the light control layer 253 is or are provided with a function of a heat radiation reflective layer rather than a heat radiation reflective layer separate from the light control element 25th provide. In this case, compared with the case of providing a heat ray reflective layer separately from the light control element 25th the influence of the detection capability of the device 300 can be reduced. In other words, the change in the light control element 25th due to heat rays can be suppressed while the detection capability of the device 300 is maintained. In particular, compared with the case of providing a heat ray reflective layer separately from the light control element 25th a decrease in visible light transmission and a change in the color of a portion of the windshield 20th with the included light control element 25th can be suppressed in the light transmission mode.

Here, the change in color is set as the difference between the maximum value and the minimum value of transmittance at predetermined wavelengths (436 nm, 546 nm and 700 nm) and is determined to be within an allowable range when the difference between the maximum value and the minimum value of the transmittance at the given wavelengths (436 nm, 546 nm and 700 nm) is less than or equal to 12%. It should be noted that the predetermined wavelengths (436 nm, 546 nm and 700 nm) are wavelengths corresponding to blue, green and red in the CIE (International Commission on Illumination) RGB colorimetric system, and that a difference in transmittance at the three wavelengths greater than 12% adversely affects the detection capability of the device 300.

It should be noted that to prevent the light control element 25th gets hot so that it is broken down, the conductive thin film 252 and / or the conductive thin film 254 with the function of a heat radiation reflecting layer can or can be provided; and that it is advantageous that at least the conductive thin film 252 , which is arranged on the outside of the vehicle, has the function of heat ray reflection. This can effectively prevent the light control element 25th gets hot due to heat rays, and the risk prevent the light control element 25th is dismantled. It is also preferred that the energy reflectance of the information transmission / reception area 26 is greater than or equal to 25%. This can effectively prevent the light control element 25th gets hot due to heat rays, and the risk prevent the light control element 25th is dismantled.

In the case where the conductive thin film 252 and / or the conductive thin film 254 is or are provided with the function of a heat ray reflecting layer, any of the above-exemplified materials may be used as the material of the conductive thin film 252 and / or the conductive thin film 254 be used.

However, it is preferable as a conductive thin film 252 and / or conductive thin film 254 to use a laminated film comprising n layers (where n is an integer greater than or equal to 2) of functional layers containing a material that reflects infrared rays and n + 1 layers of dielectric layers laminated to be surrounding the functional layers. By using a laminated film as a conductive thin film 252 and / or conductive thin film 254 For example, the energy reflectance of the information transmission / reception area 26 can be increased (eg, greater than or equal to 25%) and the effect of suppressing degradation of the light control element 25th can be improved.

For example, a laminated film comprising two layers of functional layers containing silver as a material for reflecting infrared rays and three layers of dielectric layers laminated so as to surround the functional layers; or a laminated film comprising three layers of functional layers containing silver and four layers of dielectric layers laminated so as to surround the functional layers can be used.

In the case of using silver as a material for reflecting infrared rays, functional layers containing silver may be formed from only silver, or they may be formed as a metal layer or alloy layer containing silver as a main component. In the case of using silver as the main component, metal elements other than silver such as Pd, Au, Cu, Pt and the like may be contained. The film thickness of the functional layer or the dielectric layer can be appropriately set depending on the total number of layers and the constituent materials of each layer, and can be set, for example, within a range of several nm to several hundreds of nm.

The light control layer 253 is between the conductive thin film 252 and the conductive thin film 254 arranged. As a light control layer 253 For example, a suspended particle assembly (SPD) film can be used. As the SPD film, there can be used a generic SPD film which is formed so that it comprises a polymer layer which contains suspended particles which can be oriented by applying a voltage and which is sandwiched between two layers of electrical insulating films which have transparent conductive films applied to the insides. In such an SPD film, by applying a voltage between the transparent conductive films by turning the power switch on, suspended particles in the polymer layer are oriented, and the SPD film goes into a state of having high and high visible light transmittance Has transparency. In a state that the power switch is turned off, the suspended particles in the polymer layer are not oriented, and the SPD film is in a state of low visible light transmittance and low transparency.

It should be noted that as the light control layer 253 polymer dispersed liquid crystals (PDLC) can be used instead of using the SPD film. PDLC can be made by mixing a prepolymer, nematic liquid crystals and a spacer material in a specific ratio and then sandwiched between two soft transparent conductive films. The operating principles include the following. When no electric field is applied, liquid crystal droplets in a state in which the orientators are freely oriented may be randomly distributed in the polymer material. In such a case, the refractive index of the liquid crystal with respect to normal light does not coincide with that of the polymer material and causes a relatively strong scattering effect with respect to the light, and as a result, the PDLC film has an appearance with a milky white color translucent or opaque. In an electric field, the orientators of the liquid crystal droplets can be aligned along the direction of the external electric field due to the positive dielectric anisotropy. In the case where the refractive index of the liquid crystal with respect to normal light is with matches that of the polymer material, light can pass through the PDLC film, and thereby the PDLC film has a transparent appearance. In particular, a higher voltage applied to the PDLC film makes the PDLC film more transparent.

Furthermore, as the light control layer 253 Polymer network liquid crystals (PNLC); Guest-host liquid crystals; TN liquid crystals; VA liquid crystals; a photochromic, electrochromic or electrokinetic material or the like can be used.

Furthermore, it is more preferable than the light control layer 253 to use a material in which the oriented particles are perpendicular to the transparent conductive film in the case where no voltage is applied. Such a light control layer can transmit light in the case where no electric field is applied, and when a voltage is applied, the oriented particles settle so that light is absorbed or scattered. Such a light control mode is called a reverse mode and can be implemented with a liquid crystal material having a negative dielectric anisotropy.

In the case of arranging the light control element 25th In a transparent area of a window of a vehicle, in view of the risk of a separation failure caused by a shock of an accident, it is more preferable to use the light control member 25th to apply with a reverse mode.

The pair of heating busbars 256 extends in the Z direction along both ends in the Y direction of a surface of the conductive thin film 252 on the side of the glass plate 21 and is arranged so that they face each other, the light control layer 253 is arranged in between. The pair of heating busbars 256 is electrical with the conductive thin film 252 connected so that the conductive thin film 252 is heated.

One of the pair of heating bus bars 256 is, for example, a positive electrode and is connected to the positive side of a power supply such as a battery installed in the vehicle by means of a lead wire or the like. Further, the other electrode is from the pair of heating busses 256 for example, a negative electrode and is connected to the negative side of a power supply such as a battery installed in the vehicle by means of a lead wire or the like.

Once from the power source, such as a battery, through the pair of heating bus bars 256 the conductive thin film 252 Electricity is supplied to generate the conductive thin film 252 Warmth. The heat that is in the conductive thin film 252 is generated, heats the light control layer 253 ; therefore, there may be a decrease in the response speed of the light control element 25th can be prevented at a low temperature (for example, a temperature outside the vehicle around -20 ° C) and the possibly required anti-glare property can be achieved even at the low temperature.

Further, the heat resides in the conductive thin film 252 is generated, the information transmission / reception area 26 of the windshield 20th , removes frost and mist on the surfaces of the glass plates 21 and 22nd which constitute the information transmission / reception area 26, and thereby good detection by the device 300 can be ensured.

It is preferable that the amount of heat retained in the conductive thin film 252 generated by the heating busbar 256 is heated is greater than or equal to 600 W / m ² . Furthermore, it is preferably greater than or equal to 800 W / m ² and more preferably greater than or equal to 1000 W / m ² . This can reduce the response speed of the light control element 25th effectively prevent at low temperature; the ability to remove frost and fog on the surfaces of the glass panels 21 and 22nd constituting the information transmission / reception area 26; and ensure an even better detection of the device 300.

Furthermore, heat generation in the conductive thin film 252 can be effectively controlled by sensing the outside air temperature. For example, in the case where the outside air temperature is higher than 5 ° C, the decrease in the response speed of the light control element is 25th low; therefore, the conductive thin film can 252 can be controlled so that it is not normally heated, and when the outside air temperature falls below 5 ° C, it is heated, causing a decrease in the response speed of the light control element 25th is prevented. As a result, unnecessary power consumption while the outside air temperature is high can be restrained, and in the case of a high outside temperature, the intermediate layer can be prevented from being removed 23 and the light control element 25th become excessively hot, so they are due to heat generated in the conductive thin film 252 is generated, are degraded.

It should be noted that the pair of heating busbars 256 electrically with the conductive thin film 254 instead of the conductive thin film 252 can be connected. In this case, the conductive thin film 254 be heated. Further can the pair of heating busbars 256 electrically with the conductive thin film 252 and another pair of heating bus bars can be electrically connected to the conductive thin film 254 get connected. In this case, the conductive thin films 252 and 254 be heated and thereby the total heat generation can be increased.

Although not in the cross section in the 2 B) is visible, the pair of light control bus bars extend 257 in the Y direction along one end in the Z direction of the surface of the conductive thin film 252 on the side of the glass plate 21 . One of the pair of lighting control busbars 257 is electrical with the conductive thin film 252 connected, the other is electrically connected to the conductive thin film 254 connected and the conductive thin films 252 and 254 are powered so that the light control layer 253 is operated. The pair of lighting control busbars 257 is independent of the pair of heating bus bars 256 .

One electrode from the pair of light control busses 257 is, for example, a positive electrode and is connected to the positive electrode of the power supply such as a battery installed in the vehicle by means of a lead wire or the like. Also, the other electrode is from the pair of light control busses 257 for example, a negative electrode and is connected to the negative electrode of the power supply such as a battery installed in the vehicle by means of a lead wire or the like.

When the light control layer 253 from the power source, such as a battery, through the pair of light control busses 257 a voltage is applied, the transmittance of the light control layer becomes 253 switched depending on the voltage.

As a heating busbar 256 and lighting control busbars 257 a silver paste is preferably used. The silver paste can be applied, for example, by a printing method such as screen printing. The heating busbar 256 and the lighting control busbars 257 can be prepared from at least one metal selected from a group including silver, copper, tin, gold, aluminum, iron, tungsten and chromium by sputtering or the like; an alloy containing two or more metals selected from this group; or a conductive organic polymer. It can also be used as a heating busbar 256 and lighting control busbars 257 Copper tapes, flat braided copper cables, or copper adhesive tapes that have a conductive adhesive can be used.

The light control element 25th has a light transmission mode (a high visible light transmittance mode) and a light absorption mode (a low visible light transmittance mode). Although the maximum visible light transmission of the information transmission / reception area 26, which is the light control element 25th in the light transmission mode is within an acceptable range, if it is greater than or equal to 40%, it is preferably greater than or equal to 50%. By setting the maximum visible light transmission of the information transmission / reception area 26, which is the light control element 25th includes, in the light transmission mode to greater than or equal to 50%, good detection by the device 300 can be sufficiently ensured. It should be noted that the maximum visible light transmittance stands for visible light transmittance in a state where the voltage applied to the light control layer 253 is set so that the visible light transmittance becomes maximum.

For example, it is in the case where the light control element 25th operates in the light transmission mode while being energized, preferably to cause the maximum visible light transmission to become greater than or equal to 50%. In this case, while being energized, it is more preferable to make the maximum visible light transmittance greater than or equal to 60%, and more preferable to make the maximum visible light transmittance greater than or equal to 70%. Furthermore, it is in the case where the light control element 25th operates in the light absorption mode while not being powered, it is preferable to cause the maximum visible light transmittance to be less than 20%. Furthermore, it is also preferred that the transmittance for visible light is greater than or equal to 5%. This is because less than 5% makes it difficult to see outside of the vehicle.

The light control element 25th can work in the light transmission mode while not receiving power. In this case, it is only necessary to reverse the power / no power control. Further, in this case, it is preferable to cause the maximum visible light transmittance to be greater than or equal to 50%, more preferable to cause it to be greater than or equal to 60%, and even more preferable to cause that it becomes greater than or equal to 70%; and it is preferable to cause the minimum visible light transmittance to become greater than or equal to 5% in the light absorption mode.

By including the light control element 25th in the windshield 20th For example, the amount of light transmitted through the information transmission / reception area 26 can be adjusted depending on the amount of light incident on the information transmission / reception area 26 from outside the vehicle. For example, in the case where the amount of incident light is excessive due to direct sunlight or the headlights of an oncoming vehicle, by decreasing the visible light transmittance, the amount of light passing through the information broadcast receiving area can be reduced 26th transmitted, so that an appropriate amount of light is incident on the device 300. Further, in the case where the amount of light falling on the information transmitting area is not excessive, by changing the visible light transmittance in a low transmittance area to a high value, the information transmitting / receiving area 26 can be set so that that it transmits a sufficient amount of light, whereby a suitable amount of light falls on the device.

It is preferred that the windshield 20th a control device for measuring the amount of light falling on the information sending / receiving area 26 from outside the vehicle, so that the power supply and the loss of power supply of the light control element 25th can be controlled depending on the amount of light. For example, in the case of using a light control element having a high transmittance of visible light while it is being energized, as the light control element 25th by using such a control device, a state in which the power is on can be maintained in the case where the amount of incident light is not excessive, and the power is cut off in the case where the amount of incident light is due to a Backlight or the like is excessive. As a result, the amount of light that passes through the information transmission / reception area 26 can always be optimized so that an appropriate amount of light is incident on the device 300. In the case of using the light control element 25th with a high visible light transmittance while unpowered, the same effect can be expected by reversing the power / no power control.

The glass plate 21 who have favourited glass plate 22nd and the intermediate layer 23 are described in detail.

By the windshield 20th can the surface 21a the glass plate 21 on the inside of the vehicle (the inside surface of the windshield 20th ) and a surface 22a the glass plate 22nd on the outside of the vehicle (the outside surface of the windshield 20th ) be flat surfaces or curved surfaces.

As glass plates 21 and 22nd For example, soda lime glass, an inorganic glass such as aluminosilicate, an organic glass or the like can be used. In the case where the glass plates 21 and 22nd are an inorganic glass, they can be produced, for example, by a float process.

It is preferred that the plate thickness of the glass plate 22nd that is on the outside of the windshield 20th is positioned is greater than or equal to 1.8 mm and less than or equal to 3 mm at the thinnest portion. When the plate thickness of the glass plate 22nd is greater than or equal to 1.8 mm, the strength is sufficient in terms of resistance to pebbles or the like; and when the thickness is less than or equal to 3 mm, the mass of the laminated glass is not too large, and it is preferable in terms of fuel efficiency of the vehicle. The plate thickness of the glass plate 22nd is preferably greater than or equal to 1.8 mm and less than or equal to 2.8 mm and more preferably greater than or equal to 1.8 mm and less than or equal to 2.6 mm at the thinnest portion.

It is preferred that the plate thickness of the glass plate 21 that are on the inside of the windshield 20th is positioned greater than or equal to 0.3 mm and less than or equal to 2.3 mm. A plate thickness of the glass plate 21 greater than or equal to 0.3 mm improves handling and a plate thickness less than or equal to 2.3 mm makes the mass of the windshield 20th not too big. It should be noted that the glass plate 21 and the glass plate 22nd may have a wedge-shaped cross-section.

The plate thickness of the glass plates must be 21 and 22nd not be constant at all points and may vary from point to point. For example, one or both of the glass plates can be used 21 and 22nd be provided with a portion wedge-shaped in cross section in which the thickness of the upper end in the vertical direction is greater than that of the lower end when the windshield 20th is attached to the vehicle.

In the case where the windshield 20th has a curved shape after the glass plates 21 and 22nd formed by a float method or the like, bending is performed before adhering to the intermediate layer 23 takes place. The bending is done by heating and softening the glass. The The heating temperature of the glass during bending is about 550 ° C to 700 ° C.

As an intermediate layer 23 showing the glass plate 21 and the glass plate 22nd a thermoplastic resin is often used; As such thermoplastic resins, for example, a plasticized polyvinyl acetal resin, a plasticized polyvinyl chloride resin, a saturated polyester resin, a plasticized saturated polyester resin, a polyurethane resin, a plasticized polyurethane resin, an ethylene-vinyl acetate copolymer resin, an ethylene-ethyl acrylate copolymer resin and the like can be mentioned as those conventionally mentioned be used in this type of application. Furthermore, a resin composition containing a modified block copolymer hydride which is present in the Japanese Patent No. 6065221 is described.

Of these, a plasticized polyvinyl acetal resin is suitably used because it has an excellent balance of properties including transparency, weather resistance, strength, adhesive strength, permeation tolerance, impact energy absorption, moisture resistance, heat insulation and sound insulation. One of these thermoplastic resins can be used alone, or two or more kinds can be used in combination. It should be noted that “plasticized” in the above “plasticized polyvinyl acetal resin” means that it has been plasticized by adding a plasticizer. The same is true of the other plasticized resins.

As the above-described polyvinyl acetal resin, there can be used a polyvinyl formal resin obtained by reacting a polyvinyl alcohol (hereinafter referred to as “PVA”, if necessary) with formaldehyde; a polyvinyl acetal resin in a narrow sense obtained by reacting PVA with acetaldehyde; and a polyvinyl butyral resin (may be referred to as “PVB” hereinafter, if necessary) obtained by reacting PVA with n-butyraldehyde; and the like. In particular, PVB is recommended as being suitable because it has an excellent balance of properties including transparency, weatherability, strength, adhesive strength, permeation tolerance, impact energy absorption, moisture resistance, heat insulation and sound insulation. It should be noted that one of these polyvinyl acetal resins can be used alone, or two or more kinds can be used in combination. The material that makes up the intermediate layer 23 but is not limited to a thermoplastic resin. Furthermore, the intermediate layer 23 functional particles such as infrared absorbers, ultraviolet absorbers, luminescent agents and the like.

It is preferred that the film thickness of the intermediate layer 23 at the thinnest portion is greater than or equal to 0.5 mm. A film thickness of the intermediate layer 23 greater than or equal to 0.5 mm provides sufficient penetration resistance required as a windshield. It is also preferred that the film thickness of the intermediate layer 23 is greater than or equal to 3 mm at the thickest section. When the maximum value of the film thickness of the intermediate layer 23 is less than or equal to 3 mm, the mass of the laminated glass is not too large. The maximum value of the intermediate layer 23 is more preferably less than or equal to 2.8 mm and even more preferably less than or equal to 2.6 mm. Furthermore, the intermediate layer 23 have a wedge shape in cross section.

It should be noted that the intermediate layer 23 may have three or more layers. For example, by forming the intermediate layer to have three layers and setting the hardness of the middle layer to be lower than the hardness of the layers on both sides by setting a plasticizer or the like, the sound insulation property of the laminated glass can be improved. In this case, the hardness of the layers on both sides can be identical or can be different.

For the production of the intermediate layer 23 For example, the resin materials described above are appropriately selected and extruded in a heated and molten state by means of an extruder for molding. The extrusion conditions, such as the extrusion speed of the extruder, are set uniformly. Thereafter, curvatures are formed on the top and bottom according to the design of the windshield 20th For example, the resin film formed by the extrusion is optionally stretched and the intermediate layer 23 will be completed.

The intermediate layer is used to manufacture a laminated glass 23 and the light control element 25th between the glass plate 21 and the glass plate 22nd arranged to form a laminate. Then, for example, the laminate is placed in a rubber bag and bonded in a vacuum of -65 to -100 kPa at a temperature of about 70 to 110 ° C. The heating conditions, the temperature conditions and the lamination method are appropriately selected in consideration of the properties of the light control element such as not to be degraded during the lamination process.

Further, for example, by applying a bonding treatment of heating and pressing to the laminate under conditions of, for example, 100 to 150 ° C and a pressure of 0.6 to 1.3 MPa, a laminated glass having an even better durability can be obtained. In some cases, however, this heating and pressing process is not used in consideration of simplification of the process and the properties of the materials included in the laminated glass.

Between the glass plate 21 and the glass plate 22nd may or may be in addition to the intermediate layer 23 and the light control element 25th a sheet or film and / or device having functions of light emission, reflection of visible light, scattering, decoration, absorption and the like can be provided to an extent that does not impair the effects of the present application become. Such a sheet or film and a device having the above functions can be directly applied to the main surfaces of the glass plate 21 and the glass plate 22nd be formed.

As has been described, comprises the windshield 20th the light control element 25th ; and the light control element 25th comprises the light control layer 253 , the conductive thin films 252 and 254 , which is the light control layer 253 surround the lighting control busbar 257 for supplying the conductive thin films 252 and 254 with electricity to power the light control layer 253 and the heating busbars 256 of the conductive thin film 252 .

As a result, the conductive thin film can 252 by means of the heating busbar 256 to be heated; therefore, even in the case where the temperature outside the vehicle becomes lower, the temperature of the light control layer can 253 maintained so that it is higher than the temperature outside the vehicle. As a result, even if the temperature outside the vehicle becomes lower, the response speed of the light control element may decrease 25th can be prevented and the anti-glare ability when necessary can be maintained.

It is also the case with the windshield 20th preferred that the conductive thin film 252 and / or the conductive thin film 254 is or are provided with the function of a heat radiation-reflecting layer. Consequently, even if a heat ray reflective layer is separate from the light control element 25th not provided, the risk that the light control element 25th becomes hot due to heat rays, while maintaining the sensing capability of the device 300, and the risk of degradation of the light control element 25th can be prevented. Further, in this case, compared with the case of providing a heat ray reflecting layer separately from the light control element 25th a decrease in visible light transmission and a change in the color of a portion of the windshield 20th that is the included light control 25th has to be suppressed in the light transmission mode.

<Modified Example 1 of First Embodiment>

In a modified example 1 of the first embodiment, an example is shown in which one of the heating busbars also serves as a light control busbar. It should be noted that in Modified Example 1 of the first embodiment, description of the same components as in the embodiment described above may be omitted.

The 3 Fig. 13 is a plan view showing an example of a light control member according to Modified Example 1 of the first embodiment and schematically showing how the vicinity of the information sending / receiving area is visually perceived from the inside of the vehicle to the outside of the vehicle. It should be noted that the cross-sectional structure of the light control element according to Modified Example 1 of the first embodiment is identical to that in FIG 2 B) is essentially identical, and thus the illustration is omitted.

Like it in the 3 is shown facing in a windshield 20A of Modified Example 1 of the first embodiment describes a light control element 25A only one lighting control busbar 257 on that electrically with a conductive thin film 254 connected is. Otherwise the light control is 25A essentially with the light control element 25th identical.

The heating busbar 256 are electrical with the conductive thin film 252 connected; therefore, if there is a voltage between one of the heating busbars 256 and the lighting control busbar 257 is applied, the transmittance of the light control layer 253 can be switched depending on the voltage. In other words, in the light control element 25A one of the heating busbars is used 256 also as the lighting control busbar 257 .

In this way, by having one of the heating busbars 256 as a lighting control busbar 257 serves the structure of the light control element 25A compared to the structure of the light control element 25th be simplified.

<Modified Example 2 of First Embodiment>

In Modified Example 2 of the first embodiment, an example is shown in which a windshield is not laminated glass. Although the present example is preferred as a side window or a rear window, in the present specification it is described as an example of a windshield. It should be noted that in Modified Example 2 of the first embodiment, description of the same components as in the above-described embodiment may be omitted.

The 4th FIG. 13 is a cross-sectional view exemplifying a light control member according to Modified Example 2 of the first embodiment and showing a cross-section showing 2 B) corresponds to. It should be noted that, in Modified Example 2 of the first embodiment, the plan view schematically showing how the vicinity of the information broadcast receiving area is visually perceived from the inside of the vehicle to the outside of the vehicle with that in FIG 2 (a) is essentially identical; therefore, the illustration is omitted.

Like it in the 4th shown is the windshield 20B a glass (not laminated glass) for a vehicle that has a sheet of glass 22nd , a light control element 25th and an adhesive layer 27 includes. The light control element 25th is through the adhesive layer 27 to a surface 22b the glass plate 22nd glued on the inside of the vehicle.

The material of the adhesive layer 27 is not particularly limited as long as it has the function of gluing the light control member 25th and for example acrylic-based, acrylate-based, urethane-based, urethane-acrylate-based, epoxy-based, epoxy-acrylate-based, polyolefin-based, modified olefin-based, polypropylene-based, ethylene-vinyl alcohol-based, vinyl chloride-based materials -Base, chloroprene rubber base, cyanoacrylate base, polyamide base, polyimide base, polystyrene base and polyvinyl butyral base can be named. The material of the adhesive layer 27 is transparent to visible light. The thickness of the adhesive layer 27 can be set to greater than or equal to 0.2 µm and less than or equal to 70 µm, for example.

In this way it yields even in the event that the windshield 20B not laminated glass is the light control element 25th that is the heating busbar 256 for heating the conductive thin film 252 in addition to the lighting control busbar 257 to operate the light control layer 253 has substantially the same effects as in the first embodiment. Further, by providing the conductive thin film 252 and / or the conductive thin film 254 with the function of a heat ray reflecting layer, substantially the same effects as in the first embodiment can be obtained.

<Examples and Comparative Examples>

[Example 1]

In Example 1, a laminated glass with a light control element was used 25th manufactured as it is in the 2 is shown. In particular, a clear glass with a plate thickness of 2 mm was used as the glass plates 21 and 22nd used and formed into flat plates with a size of 150 mm x 150 mm. A PVB with a thickness of 0.38 mm was used as the intermediate layer 23 used.

An SPD-A as a light control element 25th had substantially the same structure as LCF-1103DHA (manufactured by Hitachi Chemical Co., Ltd., 30 µm in thickness). In particular, the light control element 25th by arranging a base material 251 on which a conductive thin film 252 is formed by sputtering ITO and a base material 255 on which a conductive thin film 254 is formed by sputtering ITO such that the conductive thin film 252 and the conductive thin film 254 a light control layer 253 include, manufactured.

The amount of heat that is in the conductive thin film 252 is generated, the one with the heating busbars 256 connected was set to 800 W / m ² . Further, the energy reflectance of a portion of the laminated glass that was the light control element was 25th includes, in this build-up, 6%.

[Example 2]

In Example 2, an Ag3 was used as the conductive thin film 252 used. Further, the amount of heat that was in the conductive thin film 252 generated with heating busbars 256 connected is set to 1000 W / m ² . Further, the energy reflectance of a portion of the laminated glass that was the light control element was 25th includes, in this setup, 35%. Except for this, a laminated glass was produced in substantially the same manner as in Example 1. It should be noted that the Ag3 is a laminated film in which three layers of functional layers containing silver and four layers of dielectric layers made of an oxide including zinc and tin as main components are alternately laminated by sputtering.

[Example 3]

In Example 3, an Ag2 was used as the conductive thin film 252 used. Further, the amount of heat that was in the conductive thin film 252 generated with heating busbars 256 connected is set to 600 W / m ² . Further, the energy reflectance of a portion of the laminated glass that was the light control element was 25th includes, in this setup, 25%. Except for this, a laminated glass was produced in substantially the same manner as in Example 1. It should be noted that the Ag2 is a laminated film in which two layers of functional layers containing silver and three layers of dielectric layers made of an oxide including zinc and tin as main components are alternately laminated by sputtering.

[Example 4]

In Example 4, an SPD-B was used as the light control element 25th has substantially the same structure as LCF-1103DHA (manufactured by Hitachi Chemical Co., Ltd., 30 µm in thickness). In particular, the light control element 25th by arranging a base material 251 on which a conductive thin film 252 is formed by sputtering ITO and a base material 255 on which a conductive thin film 254 is formed by sputtering ITO such that the conductive thin film 252 and the conductive thin film 254 a light control layer 253 include, manufactured. Except for this, a laminated glass was produced in substantially the same manner as in Example 1.

[Comparative Example 1]

In Comparative Example 1, no heating bus bars were provided. Except for this, a laminated glass was produced in substantially the same manner as in Example 1.

[Comparative Example 2]

In Comparative Example 2, as in the 5 is shown, a heat ray reflective film 35 having an Ag3 as a heat ray reflective layer 352 formed on a base material 351 in an intermediate layer 23 outward with respect to the light control element 25th included so that a laminated glass was made. Further, the energy reflectance of a portion of the laminated glass that was the light control element was 25th includes, in this setup, 35%. Except for this, a laminated glass was produced in substantially the same manner as in Example 1.

[Comparative Example 3]

In Comparative Example 3, the amount of heat generated in the conductive thin film 252 generated with heating busbars 256 connected is set to 500 W / m ² . Except for this, a laminated glass was produced in substantially the same manner as in Example 1.

[Reviews]

First, a laminated glass was placed in a low temperature environment of -20 ° C in order to improve the response speed at the low temperature of the light control element 25th to rate. Here, the response speed is a time required to change the transmittance by 50% when changing from the light absorption mode to the light transmission mode, where 100 is the difference in transmittance between the light transmission mode and the light absorption mode in the light control element 25th represents. It was rated “good” if the response speed was less than 3 seconds; or as "failed" if it was 3 seconds or more.

Second was the degradation protection of the light control element 25th rated. Specifically, a test was conducted in which the portion of the laminated glass where the light control element 25th was irradiated with ultraviolet light under conditions of ultraviolet irradiation of 180 W / m ² (300 to 400 nm) and black body temperature (BPT) of 63 ° C using a super xenon weatherometer for 3000 hours. After the test, the transmittance retention (the ratio of transmittances in the light transmission mode before and after the test) of the light control element 25th measured in the light transmission mode, and then the retention was rated as “excellent” if it was greater than or equal to 90%; as “good” if it was greater than or equal to 80% and less than 90%; or as "failed" if it was less than 80%.

Third, the visible light transmittance (Tv) was determined in the light transmission mode of the light control element 25th rated, and rated “Excellent” when the maximum visible light transmittance was greater than or equal to 60%; as “good” if it was greater than or equal to 50% and less than 60%; as “sufficient” if it was greater than or equal to 40% and less than 50%; or as "failed" if it was less than 40%.

Fourth was the change in the color of the light control element 25th evaluated in the light transmission mode. The change of color is as that Transmittance at specified wavelengths (436 nm, 546 nm and 700 nm) is defined and is rated as "good" if the difference between the maximum value and the minimum value of the transmission at the specified wavelengths (436 nm, 546 nm and 700 nm ) is less than or equal to 12%, or as "failed" if it is greater than 12%.

The conditions and results of the examples and comparative examples are shown in FIG 6th summarized. It should be noted that “fail” in any of the ratings indicates an unfavorable condition. Furthermore, any of “sufficient”, “good” and “excellent” denotes an advantageous state, with “good” being cheaper than “sufficient” and “excellent” being cheaper than “good”.

Like it in the 6th is shown in terms of the response speed at the low temperature (-20 ° C) of the light control element 25th can be seen that a decrease can be suppressed by making the conductive thin film 252 with the heating busbars 256 is provided and the conductive thin film 252 is heated so that it generates an amount of heat greater than or equal to 600 W / m ^2. It should be noted that 600 W / m ^{2 is} a sufficient amount of heat for removing fogging on the laminated glass and removing frozen moisture adhering to a pane in winter.

In contrast, in Comparative Example 1, no heating bus bars were provided and the conductive thin film 252 could not be heated; therefore, the response speed of the light control element decreased 25th at low temperature (-20 ° C). Further, in Comparative Example 3, although the heating bus bars were provided, the amount of heat contained in the conductive thin film was 252 generated was less than 600 W / m ² and was insufficient; therefore, the response speed of the light control element decreased 25th at low temperature (-20 ° C).

Regarding the degradation protection of the light control element 25th was the preservation of transmission in the light transmission mode of any light control element 25th greater than or equal to 80% and was within an allowable range. Here, in the case of using Ag2 or Ag3 as the heat ray reflective layer (in the case where the energy reflectance of the portion of the laminated glass which is the light control element 25th includes, is greater than or equal to 25%) the anti-degradation effect of the light control element 25th particularly significant.

The maximum visible light transmission in the light transmission mode of any light control element 25th was greater than or equal to 40% and was within an allowable range. In particular, in the case where the conductive thin film was 252 Ag2 is the performance both in preventing a decrease in response speed and in preventing the light control element from deteriorating 25th outstanding; In addition, it could be ensured that the maximum permeability for visible light of the light control element 25th was greater than or equal to 60% in the light transmission mode, and thus this can be considered a preferred structure.

Regarding the change in the color of the light control element 25th in the light transmission mode for Examples 1 to 4 and Comparative Examples 1 and 3, it was within an allowable range. In Comparative Example 2, however, the difference in transmittance between the maximum value and the minimum value for the given wavelengths (436 nm, 546 nm and 700 nm) was greater than 12%; therefore, the sensing capability of the device 300 has been adversely affected. In other words, in a structure in which a heat ray reflective film is used separately from a light control element, as is the case in Comparative Example 2, there was a negative effect of deteriorating the detection capability of the device 300, although the response speed of the Light control 25th at the low temperature (-20 ° C) could be improved. Hence the structure that is used in the 5 shown is not preferred.

The preferred embodiments and the like have been described in detail above; it should be noted that the present invention is not limited to the above-described embodiments and the like and can be variously changed and replaced without departing from the scope described in the claims.

The present international application claims priority on the basis of Japanese Patent Application No. 2018-168518 filed on September 10, 2018 and the entire disclosure of Japanese Patent Application No. 2018 - 168518 is incorporated herein by reference.

List of reference symbols

20, 20A, 20B

Windshield

21

Glass plate

21a, 22a, 22b

surface

22nd

Glass plate

23

Intermediate layer

24

Shading layer

25, 25A

Light control element

26th

Information sending / receiving area

27

Adhesive layer

251, 255

Base material

252, 254

Conductive thin film

253

Light control layer

256

Heating busbar

257

Lighting control busbar

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 6065221 [0068]
• JP 2018168518 [0110]
• JP 2018 [0110]
• JP 168518 [0110]

Claims (13)

Glass for a vehicle comprising: a glass plate; a transparent area defined in the glass; and a light control element which is arranged in at least a portion of an area of the glass plate which overlaps the transparent area in plan view, and which is designed so that it can switch the light transmission, wherein the light control element a light control layer, a pair of conductive thin films surrounding the light control layer, a pair of light control busses configured to supply power to the pair of conductive thin films so that the light control layer is operated, and a pair of heating bus bars configured to heat at least one of the pair of conductive thin films. Glass after Claim 1 wherein the transparent area is an information transmission / reception area through which a device installed in the vehicle transmits and / or receives information. Glass after Claim 1 or 2 wherein the light control element has a light transmission mode and a light absorption mode, and wherein the maximum visible light transmittance of the transparent area comprising the light control element is greater than or equal to 50% in the light transmission mode. Glass after Claim 3 wherein the light control element operates in the light transmission mode while it is not powered. Glass after one of the Claims 1 to 4th wherein, of the pair of conductive thin films, at least one conductive thin film disposed on a vehicle exterior has a function of heat ray reflection, and an energy reflectance of the transparent area is greater than or equal to 25%. Glass after one of the Claims 1 to 5 wherein, of the pair of conductive thin films, at least one conductive thin film disposed on a vehicle exterior contains silver. Glass after one of the Claims 1 to 6th , wherein of the pair of conductive thin films, at least one conductive thin film disposed on a vehicle exterior, n layers (where n is an integer greater than or equal to two) of functional layers containing a material that reflects infrared rays, and n + 1 comprises layers of dielectric layers laminated to surround the functional layers. Glass after one of the Claims 1 to 7th wherein the pair of heating bus bars are arranged to face each other. Glass after one of the Claims 1 to 8th wherein the pair of light control busses are independent of the pair of heating busses. Glass after one of the Claims 1 to 8th with one of the pair of heating busbars also serving as a lighting control busbar. Glass after one of the Claims 1 to 10 wherein the amount of heat generated in the conductive thin film heated by the pair of heating bus bars is greater than or equal to 600 W / m ² . Glass after one of the Claims 1 to 11 wherein the light control element is formed from one of TN liquid crystals, VA liquid crystals, guest-host liquid crystals, polymer dispersed liquid crystals, polymer network liquid crystals and a suspended particle array. A laminated glass for a vehicle comprising: the glass according to any one of Claims 1 to 12th ; an intermediate layer; and a second glass plate, wherein the glass plate and the second glass plate are bonded with the intermediate layer therebetween, and wherein the light control element is included in the intermediate layer.

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