Window glass

Abstract

This windowpane includes an interlayer disposed between a first glass plate and a second glass plate. The interlayer includes a heat generation member, a first bus bar, and a bonding layer. The heat generation member is provided in an information acquisition region that acquires outdoor information by an information acquisition device. The first bus bar supplies a first potential to the heat generation member. The bonding layer bonds the first and second glass plates. The windowpane further includes a first electrical connector. The first electrical connector is connected to the first bus bar inside the interlayer and is removed out of the interlayer. The ratio of the area of a heated region heated by the heat generation member to the cross sectional area of the conductor of the first electrical connector is between 5,000 and 200,000 inclusive.

Description

Technical Field

[0001] The present disclosure relates to window glass.

Background Art

[0002] Patent Document 1 describes a technique of disposing a bus bar and a heating wire inside a windshield of an automobile, and removing fog (water droplets) or ice by the heat generation of the heating wire. The windshield has a shielding layer along its periphery. A transmission window is provided in a part of the shielding layer, and a camera installed inside the vehicle takes pictures of the situation outside the vehicle through the transmission window. A heating wire is disposed on the transmission window, and fog or ice on the transmission window is removed by the heat generation of the heating wire.

[0003] In order to energize each bus bar and each heating wire, a connecting member is used. The connecting member is formed in a sheet shape from a conductive material. Each connecting member is fixed to each bus bar by a fixing member such as solder. Each connecting member extends from each bus bar to the upper edge of the first glass plate and is exposed from the notch of the second glass plate. At the exposed portion, a connection terminal of a cable extending from the power source of the automobile is connected by a fixing member such as solder. The first glass plate is disposed outside the vehicle more than the second glass plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The electrical connector is connected to the bus bar inside the intermediate layer disposed between the first glass plate and the second glass plate and taken out to the outside of the intermediate layer. To rapidly remove fog or ice, a large current may be passed through the bus bar. Then, in order to prevent abnormal heat generation or disconnection due to the large current, the thickness of the electrical connector may be increased. However, if the thickness of the electrical connector is too thick, bubbles are generated in the intermediate layer when the first glass plate and the second glass plate are adhered, and the appearance deteriorates.

[0006] One aspect of the present disclosure provides a technique for suppressing deterioration of the appearance of window glass and supplying a large current to the bus bar.

Means for Solving the Problems

[0007] The window glass according to one aspect of the present disclosure includes a first glass plate, a second glass plate, and an intermediate layer. The first glass plate includes an information acquisition region for acquiring outdoor information by an information acquisition device. The second glass plate is disposed opposite to the first glass plate. The intermediate layer is disposed between the first glass plate and the second glass plate. The intermediate layer includes a heating member, a first bus bar, a second bus bar, and an adhesive layer. The heating member is disposed in the information acquisition region. The first bus bar supplies a first potential to the heating member. The second bus bar supplies a second potential different from the first potential to the heating member. The adhesive layer adheres the first glass plate and the second glass plate. The window glass has a first electrical connector and a second electrical connector. The first electrical connector is connected to the first bus bar inside the intermediate layer and taken out to the outside of the intermediate layer. The second electrical connector is connected to the second bus bar inside the intermediate layer and taken out to the outside of the intermediate layer. The ratio of the area of the heating region heated by the heating member to the cross-sectional area of the conductor of the first electrical connector is 5,000 or more and 200,000 or less. The ratio of the area of the heating region to the cross-sectional area of the conductor of the second electrical connector is 5,000 or more and 200,000 or less. The first electrical connector and the second electrical connector are bent in a U shape with the second glass plate sandwiched therebetween at the periphery of the second glass plate, and the curvature radius of the bent portions of the first electrical connector and the second electrical connector is 0.5 mm to 1.2 mm. The first bus bar has a first inclined portion formed along a side of the trapezoidal information acquisition area, a first parallel portion formed along the upper side of the information acquisition area from the upper end of the first inclined portion, and a first vertical portion extending upward from one end of the first parallel portion. The second bus bar has a second inclined portion formed along a side of the trapezoidal information acquisition area, a second parallel portion formed along the upper side of the information acquisition area from the upper end of the second inclined portion, and a second vertical portion extending upward from one end of the second parallel portion.

Advantages of the Invention

[0008] According to one aspect of the present disclosure, deterioration of the appearance of the window glass can be suppressed, and a large current can be supplied to the bus bar.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and the description thereof may be omitted. Also, in each drawing, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. In the specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value.

[0011] As shown in FIG. 6, the window glass 1 includes a first glass plate 2, a second glass plate 3 disposed opposite to the first glass plate 2, and an intermediate layer 4 disposed between the first glass plate 2 and the second glass plate 3. The window glass 1 is attached to the vehicle body of a vehicle such as an automobile. The first glass plate 2 is provided, for example, on the outdoor side, that is, the outside of the vehicle, rather than the second glass plate 3. The second glass plate 3 is provided, for example, on the indoor side, that is, the inside of the vehicle, rather than the first glass plate 2. Note that the number of glass plates constituting the window glass 1 may be three or more. When the number of glass plates constituting the window glass 1 is three or more, the number of intermediate films may be two or more.

[0012] The first glass plate 2 can be either inorganic glass or organic glass. Examples of inorganic glass include soda-lime glass, aluminosilicate glass, etc. Also, the inorganic glass can be either unstrengthened glass or strengthened glass. Unstrengthened glass is obtained by shaping molten glass into a plate shape and gradually cooling it. Strengthened glass is formed by creating a compressive stress layer on the surface of unstrengthened glass. The strengthened glass can be either physically strengthened glass (e.g., air-cooled strengthened glass) or chemically strengthened glass. On the other hand, examples of organic glass include transparent resins such as polycarbonate, acrylic resin, polyvinyl chloride, and polystyrene. The acrylic resin is, for example, polymethyl methacrylate. Note that the second glass plate 3 can also be either inorganic glass or organic glass, similar to the first glass plate 2.

[0013] The first glass plate 2 is formed to be convex toward the outside of the vehicle. As the bending forming of the first glass plate 2, gravity forming, press forming, or the like is used. When the first glass plate 2 is physically strengthened glass, the uniformly heated glass plate in the bending forming can be rapidly cooled from a temperature near the softening point, and the glass surface can be strengthened by generating a compressive stress on the glass surface due to the temperature difference between the glass surface and the glass interior. When the first glass plate 2 is chemically strengthened glass, after the bending forming, the glass surface can be strengthened by generating a compressive stress on the glass surface by an ion exchange method or the like. Note that the second glass plate 3 is also formed to be convex toward the outside of the vehicle, similar to the first glass plate 2.

[0014] Since the first glass plate 2 is provided on the outside of the vehicle more than the second glass plate 3, it has a thickness of 1.8 mm or more to suppress the occurrence of scratches caused by flying stones. From the viewpoints of light weight and formability, the thickness of the first glass plate 2 is 3.0 mm or less. Note that the thickness of the first glass plate 2 may be constant or may vary depending on the position.

[0015] Since the second glass plate 3 is provided closer to the vehicle interior than the first glass plate 2, it may be thinner than the first glass plate 2. From the perspective of handling performance, the thickness of the second glass plate 3 is 0.3 mm or more. Also, from the perspectives of light weight and formability, the thickness of the second glass plate 3 is 2.3 mm or less. Note that the thickness of the second glass plate 3 may be constant or may vary according to the position.

[0016] The intermediate layer 4 includes an adhesive layer 41 that adheres the first glass plate 2 and the second glass plate 3. The adhesive layer 41 is formed of a general resin, such as a thermoplastic resin like polyvinyl butyral resin (PVB), ethylene-vinyl acetate copolymer resin (EVA), or cycloolefin polymer (COP). When heated, the adhesive layer 41 exhibits adhesiveness.

[0017] The adhesive layer 41 may have either a single-layer structure or a multi-layer structure. The adhesive layer 41 may have functions other than adhesion. For example, the adhesive layer 41 may have one or more selected from a sound insulation layer, a colored transparent layer, an ultraviolet cut layer, and an infrared cut layer.

[0018] From the perspective of adhesiveness, the thickness of the adhesive layer 41 is, for example, 0.5 mm or more. Also, from the perspectives of light weight and handleability, the thickness of the adhesive layer 41 is, for example, 3 mm or less. The thickness of the adhesive layer 41 may be constant or may vary according to the position. For example, when an image of a head-up display is projected onto the window glass 1, to suppress the occurrence of double images, the thickness of the adhesive layer 41 increases from the lower side to the upper side. The adhesive layer 41 is formed in a wedge shape, and the wedge angle is, for example, 1.0 mrad or less.

[0019] The manufacturing method of the window glass 1 includes the following steps (A) to (C). (A) The first glass plate 2 and the second glass plate 3 are overlapped via the adhesive layer 41 to produce a laminate. (B) The laminate is housed inside a rubber bag, and while reducing the pressure inside the rubber bag, the rubber bag is heated to bond the first glass plate 2 and the second glass plate 3 with the adhesive layer 41. The air pressure inside the rubber bag is, for example, -100 kPa to -65 kPa based on the atmospheric pressure. The heating temperature of the rubber bag is, for example, 70°C to 110°C. (C) The laminate taken out from the rubber bag is pressure-bonded at a pressure of 0.6 MPa to 1.3 MPa while heating at, for example, 100°C to 150°C. For the pressure bonding, for example, an autoclave is used. Note that the manufacturing method of the window glass 1 may be a general one and may not include the step (C).

[0020] The window glass 1 is used, for example, as the front glass of a vehicle. In this case, an adhesive (not shown) for bonding the window glass 1 and the vehicle body is applied to the peripheral portion of the window glass 1. The adhesive is, for example, urethane. To suppress the deterioration of the adhesive due to ultraviolet rays, a light-shielding region is formed at the periphery of the window glass 1. The light-shielding region is a region where the light-shielding layer 5 is formed or a colored region of the adhesive layer 41.

[0021] As shown in FIG. 1, the light-shielding layer 5 may be formed over the entire periphery of the window glass 1. The light-shielding layer 5 is formed, for example, by firing a paste of black ceramics. The paste of black ceramics is applied to the first glass plate 2 or the second glass plate 3 and is fired simultaneously with the bending of the first glass plate 2 or the second glass plate 3. Note that the light-shielding layer 5 may be formed by firing a colored organic ink.

[0022] The light-shielding layer 5 is formed, for example, on both the second surface 12 and the fourth surface 14 among the first surface 11, the second surface 12, the third surface 13, and the fourth surface 14 of the window glass 1. The first surface 11 is the main surface facing the outside of the vehicle of the first glass plate 2. The second surface 12 is the main surface facing the inside of the vehicle of the first glass plate 2. The third surface 13 is the main surface facing the outside of the vehicle of the second glass plate 3. The fourth surface 14 is the main surface facing the inside of the vehicle of the second glass plate 3. Note that the light-shielding layer 5 may be formed on only one of the second surface 12 and the fourth surface 14.

[0023] In addition to the first glass plate 2, the second glass plate 3, the intermediate layer 4, and the light-shielding layer 5, the window glass 1 may have one or more selected from, for example, a water-repellent layer, an ultraviolet cut layer, an infrared cut layer, a heat-insulating layer, and a colored transparent layer. The heat-insulating layer has a function of suppressing radiative heat transfer. The colored transparent layer has an antiglare function of reducing the transmittance of visible light. The arrangement of these functional layers may be on the outside or inside of the window glass 1.

[0024] Note that, in this embodiment, the window glass 1 is used as the front glass of a vehicle, but it may also be used as a rear glass or a side glass.

[0025] The second glass plate 3 has an information acquisition region 31. The information acquisition region 31 is a region for acquiring outdoor information, that is, information outside the vehicle, by the information acquisition device 9. The first glass plate 2 also has an information acquisition region 21, similar to the second glass plate 3. The information acquisition region 21 of the first glass plate 2 and the information acquisition region 31 of the second glass plate 3 substantially coincide. Therefore, hereinafter, the information acquisition region 31 of the second glass plate 3 will be described, and the description of the information acquisition region 21 of the first glass plate 2 will be omitted.

[0026] The information acquisition device 9 includes, for example, a light-receiving element that receives visible light or infrared light, and acquires an image outside the vehicle with the light-receiving element. The information acquisition device 9 is, for example, a camera such as a visible light camera or an infrared camera, or LiDAR (Light Imaging Detection and Ranging). LiDAR irradiates laser light, receives the reflected light from the object, and measures the distance and direction to the object. LiDAR scans the laser light throughout the information acquisition region 31.

[0027] As shown in FIG. 1, the information acquisition area 31 is, for example, an opening in the light shielding layer 5 and is surrounded by the light shielding layer 5 on all four sides (top, bottom, left, and right). The light shielding layer 5 includes, for example, a frame-shaped portion 51 and a protruding portion 52 that protrudes downward from the upper edge of the frame-shaped portion 51. The protruding portion 52 is, for example, trapezoidal. The information acquisition area 31 is provided in the protruding portion 52. In this embodiment, the information acquisition area 31 is surrounded by the light shielding layer 5 on all four sides (top, bottom, left, and right), but it may also be surrounded on three sides (top, left, and right), that is, it may be open at the bottom.

[0028] As shown in FIG. 3, the information acquisition area 31 has a trapezoidal shape and has a horizontal upper side 32 and a horizontal lower side 33. In this specification, the trapezoid includes, in addition to the trapezoid in the mathematical sense, a shape including a curve in part and a shape in which the upper side 32 and the lower side 33 are not completely parallel and are inclined at an angle of 10° or less. The X-axis direction parallel to the upper side 32 and the lower side 33 is the horizontal direction, and the Z-axis direction perpendicular to the horizontal direction is the vertical direction. The Y-axis direction is the thickness direction. The positive side of the Y-axis direction is the inside of the vehicle, and the negative side of the Y-axis direction is the outside of the vehicle.

[0029] The intermediate layer 4 has a heating wire 42 as a heating member disposed in the information acquisition area 31. The heating wire 42 generates heat by the supply of electric power and removes fog or ice adhering to the information acquisition area 31.

[0030] The heating wire 42, for example, crosses the information acquisition area 31 in the horizontal direction, and a plurality of heating wires are provided at intervals in the vertical direction. As shown in FIG. 7, the heating wire 42 may also cross the information acquisition area 31 in the vertical direction, and a plurality of heating wires may be provided at intervals in the horizontal direction. Further, the heating wire 42 may be arranged in a mesh shape. That is, a heating wire extending in the vertical direction and a heating wire extending in the horizontal direction may be provided. The shape of the mesh of the mesh is not limited to a quadrilateral, and may be, for example, a triangle, a hexagon, a circle, or the like. Also, the shape of the mesh of the mesh may be irregular.

[0031] The heating wire 42 may be straight, but may be a wavy line such as a sine curve in order to suppress the generation of glare. Glare is a phenomenon in which streak-like light is visually recognized, and is a phenomenon caused by diffraction and interference of light. If the phases of a plurality of adjacent heating wires 42 are shifted, the generation of glare can be further suppressed. Note that the period of the heating wire 42 may change on the way from the first bus bar 43 to the second bus bar 44.

[0032] The material of the heating wire 42 is not particularly limited as long as it is a conductive material. For example, it is a pure metal selected from the group consisting of gold, silver, copper, aluminum, tin, iron, nickel, chromium, and tungsten, an alloy containing one or more metals selected from this group, carbon, or graphene. The heating wire 42 may be formed of the same material as the first bus bar 43 and the second bus bar 44, or may be integrally formed without using a conductive adhesive such as solder.

[0033] Note that the heat generating member of the intermediate layer 4 is a linear heating wire 42 in this embodiment, but may be planar. For example, the intermediate layer 4 may include a transparent conductive film as a heat generating member. Specific examples of the transparent conductive film include an indium tin oxide film (ITO film), a thin film of silver or a silver alloy, and the like.

[0034] The intermediate layer 4 includes a first bus bar 43 that supplies a first potential to one end of the heating wire 42, and a second bus bar 44 that supplies a second potential different from the first potential to the other end of the heating wire 42. Either the first potential or the second potential may be higher. The first bus bar 43 and the second bus bar 44 apply a voltage to the heating wire 42. As a result, an electric current is supplied to the heating wire 42, and Joule heat is generated.

[0035] As shown in FIG. 3, the first bus bar 43 includes an inclined portion 43a formed along a side 34 of the trapezoidal information acquisition region 31, a parallel portion 43b formed along an upper side 32 of the information acquisition region 31 from the upper end of the inclined portion 43a, and a vertical portion 43c extending upward from one end of the parallel portion 43b. The inclined portion 43a is connected to the right end portion of the heating wire 42, and the vertical portion 43c is connected to a conductor 63a of a first electrical connector 63 described later.

[0036] Similarly, the second bus bar 44 has an inclined portion 44a formed along the side 35 of the trapezoidal information acquisition region 31, a parallel portion 44b formed along the upper side 32 of the information acquisition region 31 from the upper end of the inclined portion 44a, and a vertical portion 44c extending upward from one end of the parallel portion 44b. The inclined portion 44a is connected to the left end portion of the heating wire 42, and the vertical portion 44c is connected to the conductor 64a of the second electrical connector 64 described later.

[0037] The first bus bar 43 and the second bus bar 44 have an electrical resistance lower than that of the heating wire 42, and unlike the heating wire 42, hardly generate heat. The region surrounded by the first bus bar 43, the second bus bar 44, and the heating wires 42 at both ends among the plurality of heating wires 42, for example, the region surrounded by the thick line in FIG. 3, is the heating region H heated by the heating wire 42. The heating region H is surrounded by, for example, the inclined portion 43a of the first bus bar 43, the inclined portion 43a of the second bus bar 44, the upper heating wire 42, and the lower heating wire 42.

[0038] As shown in FIG. 7, the heating region H may be surrounded by the parallel portion 43b of the first bus bar 43, the parallel portion 44b of the second bus bar 44, the leftmost heating wire 42, and the rightmost heating wire 42. The first bus bar 43 has a parallel portion 43b formed along the upper side 32 of the information acquisition region 31 and a vertical portion 43c extending upward from the parallel portion 43b. The parallel portion 43b is connected to the upper end portion of the heating wire 42, and the vertical portion 43c is connected to the conductor 63a of the first electrical connector 63 described later. On the other hand, the second bus bar 44 has a parallel portion 44b formed along the lower side 33 of the information acquisition region 31 and a vertical portion 44c extending upward from the parallel portion 44b. The parallel portion 44b is connected to the lower end portion of the heating wire 42, and the vertical portion 44c is connected to the conductor 64a of the second electrical connector 64 described later.

[0039] In a plan view (viewed in the Y-axis direction), the shape of the heating region H is, for example, the trapezoid shown in FIG. 3 or the rectangle shown in FIG. 7. In a plan view, the area of the heating region H is approximately the same as the area of the information acquisition region 31. The area B of the heating region H is, for example, 1500 mm 2 ~36000 mm 2and preferably 2500 mm 2 ~30000 mm 2 and more preferably 4000 mm 2 ~30000 mm 2 .

[0040] In addition, in plan view, the shape of the heating region H may be a shape other than the trapezoid shown in FIG. 3 or the rectangle shown in FIG. 7, and may be U-shaped as shown in FIG. 13 of Patent Document 1, for example. In this case, the shape of the heating wire 42 is also U-shaped, and the heating wire 42 includes a bent portion in the middle thereof.

[0041] In addition, as described above, the heating member may be planar. When the heating member is planar, the heating region heated by the heating member is a region surrounded by the first bus bar 43, the second bus bar 44, and the periphery of the heating member.

[0042] The first bus bar 43 is formed, for example, by firing a noble metal paste such as a silver paste or is formed by a metal ribbon such as a copper ribbon. The first bus bar 43 may be formed of a flat braided copper wire. The second bus bar 44 is formed in the same manner as the first bus bar 43.

[0043] The material of the first bus bar 43 is, like the material of the heating wire 42, a pure metal selected from the group consisting of gold, silver, copper, aluminum, tin, iron, nickel, chromium, and tungsten, or an alloy containing one or more metals selected from this group. However, the material of the first bus bar 43 may be a conductive organic polymer. The material of the second bus bar 44 is the same as the material of the first bus bar 43.

[0044] As shown in FIG. 5, the intermediate layer 4 may further include a base film 45. The base film 45 supports the heating wire 42, the first bus bar 43, and the second bus bar 44. The heating wire 42, the first bus bar 43, and the second bus bar 44 are disposed between the first glass plate 2 and the second glass plate 3 while being supported by the base film 45.

[0045] The handling property of the heating wire 42 and the like is improved by the base material film 45. In the step (A) above, the base material film 45 is disposed between the second glass plate 3 and the adhesive layer 41 in a state where the heating wire 42, the first bus bar 43, and the second bus bar 44 are directed toward the second glass plate 3. The base material film 45 is in contact with the second glass plate 3.

[0046] Note that a second adhesive layer (not shown) having a larger area than the base material film 45 may be disposed between the base material film 45 and the second glass plate 3. The second adhesive layer is configured in the same manner as the adhesive layer 41. The second adhesive layer can surely prevent the separation between the base material film 45 and the second glass plate 3. The base material film 45 is disposed between the adhesive layer 41 and the second adhesive layer.

[0047] The base material film 45 is formed of a transparent resin and is formed of, for example, the same material as the adhesive layer 41. However, the material of the base material film 45 does not necessarily exhibit adhesiveness by heating and may be, for example, polyethylene terephthalate (PET) or the like.

[0048] The periphery of the base material film 45 is disposed inside the periphery of the adhesive layer 41. Since the adhesive layer 41 has a larger area than the base material film 45, even when the base material film 45 does not have adhesiveness, the adhesive layer 41 can bond the first glass plate 2 and the second glass plate 3. The first glass plate 2 and the second glass plate 3 are larger in area than the base material film 45, like the adhesive layer 41.

[0049] Note that the arrangement of the first bus bar 43 and the conductor 63a of the first electrical connector 63 may be reversed, and the conductor 63a may be disposed between the first bus bar 43 and the base material film 45. Also, the arrangement of the second bus bar 44 and the conductor 64a of the second electrical connector 64 may be reversed, and the conductor 64a may be disposed between the second bus bar 44 and the base material film 45. Also, as described above, the base material film 45 may be disposed between the adhesive layer 41 and the second adhesive layer.

[0050] In this embodiment, the intermediate layer 4 includes the base film 45, but it may not include the base film 45. In this case, the heating wire 42, the first bus bar 43, and the second bus bar 44 are formed on the adhesive layer 41. Further, in this case, the heating wire 42, the first bus bar 43, and the second bus bar 44 may be disposed between the adhesive layer 41 and the second adhesive layer.

[0051] As shown in FIG. 3, the window glass 1 has a first electrical connector 63 connected to the first bus bar 43. The first electrical connector 63 is connected to the first bus bar 43 inside the intermediate layer 4, taken out to the outside of the intermediate layer 4, and connects the wire harness of the vehicle and the first bus bar 43.

[0052] The first electrical connector 63 includes a conductor 63a and an insulator 63b that covers the conductor 63a. The conductor 63a supplies a first potential from the wire harness of the vehicle to the first bus bar 43. The conductor 63a is formed of a metal ribbon such as a Cu ribbon, for example. On the other hand, the insulator 63b is formed of a resin, for example.

[0053] The ratio (B / A1) of the area B of the heating region H to the cross-sectional area A1 of the conductor 63a is, for example, 5,000 or more and 200,000 or less. B / A1 is a dimensionless quantity. The cross-section of the conductor 63a is a cross-section perpendicular to the flow of current. When the cross-sectional shape of the conductor 63a is rectangular, the cross-sectional area A1 of the conductor 63a is equal to the product of the width W1 and the thickness T1.

[0054] If B / A1 is 5,000 or more, the cross-sectional area A1 of the conductor 63a is sufficiently small, and the bubbles generated inside the laminate in the step (A) are small. Therefore, the bubbles are likely to disappear in the step (B) or (C), and the appearance of the finally obtained window glass 1 is good.

[0055] On the other hand, if B / A1 is 200,000 or less, the cross-sectional area A1 of the conductor 63a is sufficiently large, abnormal heat generation or disconnection of the conductor 63a does not occur, and a large current can be supplied to the heating region H. The heat generation amount per unit area of the heating region H, that is, the heat generation density is, for example, 500 W / m 2 ~2500W / m 2and preferably 700 W / m 2 ~2000 W / m 2 is.

[0056] B / A1 is preferably from 5000 to 200000, more preferably from 15000 to 200000, and still more preferably from 20000 to 200000. A1 is, for example, 0.2 mm 2 ~7.0 mm 2 and preferably 0.3 mm 2 ~6.0 mm 2 is. Incidentally, as shown in FIG. 7, when the number of the first electrical connectors 63 used for heating the heating region H is plural, A1 is the total cross-sectional area of all the conductors 63a used for heating the heating region H.

[0057] The cross-section of the conductor 63a is, for example, rectangular in shape, and the ratio (T1 / W1) of the thickness T1 to the width W1 is from 0.007 to 0.04. T1 / W1 is a dimensionless quantity.

[0058] If T1 / W1 is 0.007 or more, the thickness T1 of the conductor 63a is sufficiently thick, there is no risk of disconnection due to bending deformation of the conductor 63a (see, for example, FIG. 8), and the handleability is good. On the other hand, if T1 / W1 is 0.04 or less, the thickness T1 of the conductor 63a is sufficiently thin, and the bubbles generated inside the laminate in the step (A) are small. Therefore, the bubbles are likely to disappear in the step (B) or (C), and the appearance of the finally obtained window glass 1 is good.

[0059] T1 / W1 is preferably from 0.009 to 0.035, and more preferably from 0.009 to 0.012. T1 is, for example, 10×10 -3 mm~400×10 -3 mm, and preferably 70×10 -3 mm~200×10 -3 mm. On the other hand, W1 is, for example, from 1 mm to 25 mm, preferably from 3 mm to 15 mm.

[0060] Further, the window glass 1 has a second electrical connector 64 connected to the second bus bar 44. The second electrical connector 64 is connected to the second bus bar 44 inside the intermediate layer 4, taken out to the outside of the intermediate layer 4, and connects the vehicle wire harness and the second bus bar 44.

[0061] The second electrical connector 64 includes a conductor 64a and an insulator 64b covering the conductor 64a. The conductor 64a supplies a second potential from the vehicle wire harness to the second bus bar 44. The conductor 64a is formed of a metal ribbon such as a Cu ribbon, for example. On the other hand, the insulator 64b is formed of a resin, for example.

[0062] The ratio (B / A2) of the area B of the heating region H to the cross-sectional area A2 of the conductor 64a is, for example, 5,000 or more and 200,000 or less. B / A2 is a dimensionless quantity. The cross-section of the conductor 64a is a cross-section orthogonal to the flow of the current. When the cross-sectional shape of the conductor 64a is rectangular, the cross-sectional area A2 of the conductor 64a is equal to the product of the width W2 and the thickness T2.

[0063] If B / A2 is 5,000 or more, the cross-sectional area A2 of the conductor 64a is sufficiently small, and the bubbles generated inside the laminate in the step (A) are small. Therefore, the bubbles are likely to disappear in the step (B) or (C), and the appearance of the finally obtained window glass 1 is good. On the other hand, if B / A2 is 200,000 or less, the cross-sectional area A2 of the conductor 64a is sufficiently large, abnormal heat generation or disconnection of the conductor 64a does not occur, and a large current can be supplied to the heating region H.

[0064] B / A2 is preferably 5,000 to 200,000, more preferably 15,000 to 200,000, and still more preferably 20,000 to 200,000. A2 is, for example, 0.2 mm 2 ~7.0 mm 2 and preferably 0.3 mm 2 ~6.0 mm 2 If there are a plurality of second electrical connectors 64 used for heating the heating region H (not shown), A2 is the total cross-sectional area of all the conductors 64a used for heating the heating region H.

[0065] The cross-section of the conductor 64a is, for example, rectangular in shape, and the ratio (T2 / W2) of the thickness T2 to the width W2 is 0.007 to 0.04. T2 / W2 is a dimensionless quantity.

[0066] If T2 / W2 is 0.007 or more, the thickness T2 of the conductor 64a is sufficiently thick, there is no risk of disconnection due to bending deformation of the conductor 64a, and the handleability is good. On the other hand, if T2 / W2 is 0.04 or less, the thickness T2 of the conductor 64a is sufficiently thin, and the bubbles generated inside the laminate in the step (A) are small. Therefore, the bubbles are likely to disappear in the step (B) or (C), and the appearance of the finally obtained window glass 1 is good.

[0067] T2 / W2 is preferably 0.009 to 0.035, and more preferably 0.009 to 0.012. T2 is, for example, 10×10 -3 mm to 400×10 -3 mm, preferably 70×10 -3 mm to 200×10 -3 mm. On the other hand, W2 is, for example, 1 mm to 25 mm, preferably 3 mm to 15 mm.

[0068] In this embodiment, the cross-section of the conductor 63a of the first electrical connector 63 and the cross-section of the conductor 64a of the second electrical connector 64 have the same shape and the same dimensions, but they may have different shapes or different dimensions.

[0069] As shown in FIG. 2, the first electrical connector 63 and the second electrical connector 64 are arranged at intervals along the periphery of the second glass plate 3, more specifically, along the upper edge of the second glass plate 3. In other words, the first electrical connector 63 and the second electrical connector 64 are arranged at intervals along the periphery of the first glass plate 2, more specifically, along the upper edge of the first glass plate 2.

[0070] As shown in FIG. 4, the distance G between the first electrical connector 63 and the second electrical connector 64 is, for example, 10 mm or more. If G is 10 mm or more, in the step (B) or (C) above, the adhesive layer 41 deforms so as to fill the space between the first electrical connector 63 and the second electrical connector 64, and there are few air bubbles inside the finally obtained window glass 1. G is preferably 20 mm or more. On the other hand, G is preferably 400 mm or less. If G is 400 mm or less, it is easy to connect the first electrical connector 63 or the second electrical connector 64 to the vehicle body side electric wire (for example, the wire harness 73 shown in FIG. 8). Note that G is smaller than the lateral width of the heating region H.

[0071] The distance G between the first electrical connector 63 and the second electrical connector 64 is, for example, equal to or greater than the width TW1 of the first electrical connector 63 and equal to or greater than the width TW2 of the second electrical connector 64. If G is equal to or greater than TW1 and TW2, in the step (B) or (C) above, the adhesive layer 41 deforms so as to fill the space between the first electrical connector 63 and the second electrical connector 64, and there are few air bubbles inside the finally obtained window glass 1. G is preferably at least twice TW1 and at least twice TW2. On the other hand, G is preferably at most 40 times TW1 and at most 40 times TW2. If G is at most 40 times TW1 and at most 40 times TW2, it is easy to connect the first electrical connector 63 or the second electrical connector 64 to the vehicle body side electric wire. For example, TW1 is equal to or less than W1 + 5 mm, and TW2 is equal to or less than W2 + 5 mm. Preferably, TW1 is equal to or less than W1 + 2 mm, and TW2 is equal to or less than W2 + 2 mm.

[0072] As shown in FIG. 8, the first electrical connector 63 is bent in a U shape along, for example, the upper edge of the second glass plate 3, and is connected to the wire harness 73 of the vehicle by soldering or the like on the vehicle interior side of the second glass plate 3. The radius of curvature of the bent portion of the first electrical connector 63 is, for example, 0.5 mm to 1.2 mm. If the radius of curvature of the bent portion of the first electrical connector 63 is 0.5 mm or more, disconnection of the conductor 63a can be suppressed. On the other hand, if the radius of curvature of the bent portion of the first electrical connector 63 is 1.2 mm or less, the adhesion between the bent portion of the first electrical connector 63 and the second glass plate 3 is good, and the second glass plate 3 is easy to handle. The radius of curvature of the bent portion of the first electrical connector 63 is, for example, half of the thickness of the second glass plate 3. Although not shown, the second electrical connector 64 is also bent in a U shape along the upper edge of the second glass plate 3, and is connected to the wire harness of the vehicle by soldering or the like on the vehicle interior side of the second glass plate 3. The radius of curvature of the bent portion of the second electrical connector 64 is also, for example, 0.5 mm to 1.2 mm. The radius of curvature of the bent portion of the second electrical connector 64 is, for example, half of the thickness of the second glass plate 3.

[0073] The periphery of the second glass plate 3 may have a notch 32 with a depth D of 2 mm or less, preferably 1 mm or less, from the periphery of the second glass plate 3 at the position where the first electrical connector 63 is disposed. Note that the notch 32 may not be provided. The smaller the notch 32 is, the smaller the shape difference between the first glass plate 2 and the second glass plate 3 is, so the difference in bending during bending forming is reduced, and the risk of cracking and foaming can be reduced.

[0074] Although not shown, the periphery of the second glass plate 3 may have a notch with a depth of 2 mm or less, preferably 1 mm or less, from the periphery of the second glass plate 3 at the position where the second electrical connector 64 is disposed, or may not have a notch. The smaller the notch 32 is, the smaller the shape difference between the first glass plate 2 and the second glass plate 3 is, so the difference in bending during bending forming is reduced, and the risk of cracking and foaming can be reduced.

Example

[0075] The experimental data will be described below with reference to Table 1. Examples 2 to 4 are examples, and Examples 1 and 5 to 6 are comparative examples. In Examples 1 to 6, window glass was manufactured under the same conditions except for the conditions shown in Table 1. The thickness of the first glass plate was 2 mm, the thickness of the second glass plate was 2 mm, and the thickness of the PVB sheet as the adhesive layer was 0.76 mm. Also, in plan view, the size of the window glass was 1500 mm in width and 1000 mm in length. The heating wire as the heat generating member, the first bus bar, and the second bus bar were formed by baking a silver paste and arranged as shown in FIGS. 2 and 3. The base film for supporting the heating wire etc. was a PVB sheet with a thickness of 0.76 mm. One first electrical connector and one second electrical connector were provided. The first electrical connector and the second electrical connector were arranged with a 10 mm interval along the upper edge of the second glass plate. The potential difference between the first electrical connector and the second electrical connector, that is, the potential difference between the first bus bar and the second bus bar, was 1.5 V. The heat generation density in the heating region was 1000 W / m 2 ². Also, the radius of curvature of the bent portion along the upper edge of the second glass plate for each of the first electrical connector and the second electrical connector was 1 mm. In Examples 1 to 6, after manufacturing the window glass, the presence or absence of bubbles in the window glass and the durability during energization were examined. The presence or absence of bubbles was confirmed visually. The durability during energization was evaluated by the presence or absence of abnormal heat generation between the first electrical connector and the second electrical connector. In Table 1, "〇" means that there was no abnormal heat generation in all the window glasses when 30 window glasses were manufactured, "△" means that there was abnormal heat generation with a probability of less than 10% when 30 window glasses were manufactured, and "×" means that there was abnormal heat generation with a probability of 10% or more when 30 window glasses were manufactured.

[0076]

Table 1

[0077] In Example 7, the thickness of the second glass plate was changed to 1 mm, and the radius of curvature of the bent portion along the upper edge of the second glass plate of each of the first electrical connector and the second electrical connector was changed to 0.5 mm, and window glass was manufactured under the same conditions as in Example 3. When the durability of the window glass manufactured in Example 7 during energization was examined, there was no abnormal heat generation in all 30 window glasses, and the evaluation was "〇". On the other hand, in Example 8, the thickness of the second glass plate was changed to 0.8 mm, and the radius of curvature of the bent portion along the upper edge of the second glass plate of each of the first electrical connector and the second electrical connector was changed to 0.4 mm, and window glass was manufactured under the same conditions as in Example 3. When the durability of the window glass manufactured in Example 8 during energization was examined, disconnection occurred in the first electrical connector and the second electrical connector with a probability of less than 10% among 30 window glasses, resulting in abnormal heat generation, and the evaluation was "△".

[0078] As described above, the window glass according to the present disclosure has been described, but the present disclosure is not limited to the above-described embodiments and the like. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope described in the claims. Naturally, they also belong to the technical scope of the present disclosure.

[0079] For example, the window glass is attached to a vehicle in the above-described embodiment, but may be attached to a building.

[0080] This application claims priority based on Japanese Patent Application No. 2020-080469 filed with the Japan Patent Office on April 30, 2020, and incorporates the entire contents of Japanese Patent Application No. 2020-080469 into this application.

Explanation of Reference Numerals

[0081] 1 Window glass 2 First glass plate 21 Information acquisition area 3 Second glass plate 31 Information acquisition area 4 Intermediate layer 42 Heating wire (heating member) 43 First bus bar 44 Second bus bar 63 First electrical connector 63a Conductor 64 Second electrical connector 64a Conductor H Heating area

Claims

1. A window glass having a first glass plate including an information acquisition area for acquiring outdoor information by an information acquisition device, a second glass plate disposed opposite to the first glass plate, and an intermediate layer disposed between the first glass plate and the second glass plate, The intermediate layer includes a heating member disposed in the information acquisition area, a first bus bar for supplying a first potential to the heating member, a second bus bar for supplying a second potential different from the first potential to the heating member, and an adhesive layer for bonding the first glass plate and the second glass plate. The intermediate layer further has a first electrical connector connected to the first bus bar inside the intermediate layer and taken out to the outside of the intermediate layer, and a second electrical connector connected to the second bus bar inside the intermediate layer and taken out to the outside of the intermediate layer. The ratio of the area of the heating area heated by the heating member to the cross-sectional area of the conductor of the first electrical connector is 5,000 or more and 200,000 or less. The ratio of the area of the heating area to the cross-sectional area of the conductor of the second electrical connector is 5,000 or more and 200,000 or less. The first electrical connector and the second electrical connector are bent in a U shape with the second glass plate sandwiched at the periphery of the second glass plate, and the radius of curvature of the bent portions of the first electrical connector and the second electrical connector is 0.5 mm to 1.2 mm. The first bus bar has a first inclined portion formed along a side of the trapezoidal information acquisition area, a first parallel portion formed along the upper side of the information acquisition area from the upper end of the first inclined portion, and a first vertical portion extending upward from one end of the first parallel portion. The second bus bar has a second inclined portion formed along a side of the trapezoidal information acquisition area, a second parallel portion formed along the upper side of the information acquisition area from the upper end of the second inclined portion, and a second vertical portion extending upward from one end of the second parallel portion, the window glass.

2. The cross-section of the conductor of the first electrical connector is rectangular in shape, and the ratio of the thickness to the width is 0.007 to 0.

04. The cross-section of the conductor of the second electrical connector is rectangular in shape, and the ratio of the thickness to the width is 0.007 to 0.

04. The window glass according to claim 1.

3. The first electrical connector and the second electrical connector are arranged at intervals along the periphery of the second glass plate. The distance between the first electrical connector and the second electrical connector is 10 mm or more. The window glass according to claim 1 or 2.

4. The first electrical connector and the second electrical connector are arranged at intervals along the periphery of the second glass plate. The distance between the first electrical connector and the second electrical connector is equal to or greater than the width of the first electrical connector and equal to or greater than the width of the second electrical connector. The window glass according to any one of claims 1 to 3.

5. The second glass plate is arranged on the indoor side of the first glass plate. The first electrical connector and the second electrical connector are arranged at intervals along the periphery of the second glass plate. The periphery of the second glass plate has a notch with a depth of 2 mm or less from the periphery of the second glass plate at the positions where the first electrical connector and the second electrical connector are arranged, or has no notch. The window glass according to any one of claims 1 to 4.

6. The second glass plate is provided on the vehicle interior side of the first glass plate. The first electrical connector and the second electrical connector are bent in a U shape with the second glass plate sandwiched at the upper edge of the second glass plate, and are connected to the wire harness of the vehicle on the vehicle interior side of the second glass plate. The window glass according to any one of claims 1 to 5.

7. It has a light-shielding layer including a frame-shaped portion surrounding the entire periphery of the window glass and a protruding portion protruding downward from the upper edge of the frame-shaped portion. The information acquisition region is provided on the protruding portion, surrounded by the light shielding layer on three sides of the upper, left, and right, and open downward, and is the window glass according to any one of claims 1 to 6.

8. The width TW1 of the first electrical connector is equal to or less than the width W1 of the conductor of the first electrical connector + 5 mm, The width TW2 of the second electrical connector is equal to or less than the width W2 of the conductor of the second electrical connector + 5 mm, and is the window glass according to any one of claims 1 to 7.

Images