Window glass

Abstract

The window glass has an intermediate layer disposed between a first glass plate and a second glass plate. The intermediate layer includes a heating member, a first bus bar, and an adhesive layer. The heating member is disposed in an information acquisition area where outdoor information is acquired by an information acquisition device. The first bus bar supplies a first potential to the heating member. The adhesive layer bonds the first glass plate and the second glass plate. The window glass also has a first electrical connector. The first electrical connector is connected to the first bus bar inside the intermediate layer and protrudes 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.

Description

Technical Field

[0001] The present invention relates to a window glass. Background Art

[0002] Patent Document 1 discloses a technique in which a bus bar and heating wires are disposed inside a windshield of an automobile, and fog (water droplets) or ice is removed by heat generated by the heating wires. The windshield has a shielding layer along its periphery. A transmission window is provided at a part of the shielding layer, and a camera provided inside the vehicle captures the outside of the vehicle through the transmission window. The transmission window is provided with heating wires, and fog or ice on the transmission window is removed by heat generated by the heating wires.

[0003] Connection materials are used to energize each bus bar and each heating wire. The connection materials are formed in a sheet shape from a conductive material. Each connection material is fixed to each bus bar by a fixing material such as solder. Each connection material extends from each bus bar to the upper edge of the first glass plate and is exposed from a cutout of the second glass plate. A connection terminal of a cable extending from an automobile power supply is connected to the exposed portion by a fixing material such as solder. The first glass plate is disposed at a position closer to the outside of the vehicle than the second glass plate.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-212148 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] 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 protrudes to the outside of the intermediate layer. In order to quickly remove fog or ice, a large current may flow through the bus bar. Subsequently, in order to prevent abnormal heating or disconnection caused by the large current, it is sufficient to increase the thickness of the electrical connector. However, if the thickness of the electrical connector is too thick, bubbles will be generated in the intermediate layer when the first glass plate and the second glass plate are bonded, deteriorating the appearance.

[0009] One aspect of the present invention provides a technique for suppressing deterioration of the appearance of a window glass and supplying a large current to a bus bar.

[0010] Means for Solving the Problems

[0011] A window glass according to one aspect of the present invention 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 bonds the first glass plate and the second glass plate. The window glass further includes 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 protrudes to the outside of the intermediate layer. The second electrical connector is connected to the second bus bar inside the intermediate layer and protrudes 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.

[0012] Effect of the Invention

[0013] According to one aspect of the present invention, it is possible to suppress the deterioration of the appearance of the window glass and supply a large current to the bus bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a plan view showing a window glass of an embodiment, and is a plan view showing with the first glass plate and the adhesive layer removed.

[0015] Figure 2 It is an enlarged Figure 1 Plan view of region II.

[0016] Figure 3 It is showing Figure 2 Plan view of the heating region.

[0017] Figure 4 It is along Figure 2 Cross-sectional view of the window glass taken along line IV-IV.

[0018] Figure 5 It is along Figure 2 Cross-sectional view of the window glass taken along line V-V.

[0019] Figure 6 It is along Figure 2 Cross-sectional view of the window glass taken along line VI-VI.

[0020] Figure 7It is a top view showing a heating area of a modified example.

[0021] Figure 8 It is a cross-sectional view showing an example of the connection of a wire harness and an electrical connector of a vehicle. Detailed implementation mode

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding structures are denoted by the same reference numerals, and their descriptions are sometimes omitted. In addition, the X-axis direction, Y-axis direction, and Z-axis direction in each drawing are perpendicular to each other. In the specification, "~" indicating a numerical range means a range including the values described before and after it as the lower limit value and the upper limit value.

[0023] As Figure 6 shown, the window glass 1 has 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 installed, for example, on the body of a vehicle such as an automobile. The first glass plate 2 is disposed, for example, at a position closer to the outside of the vehicle than the second glass plate 3, that is, on the outside of the vehicle. The second glass plate 3 is disposed, for example, at a position closer to the inside of the vehicle than the first glass plate 2, that is, on the inside of the vehicle. In addition, 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 also be two or more.

[0024] The first glass plate 2 can be either inorganic glass or organic glass. Examples of the inorganic glass include soda-lime glass and aluminosilicate glass. The inorganic glass can be either non-strengthened glass or strengthened glass. The non-strengthened glass is glass formed by shaping molten glass into a plate shape and annealing it. The strengthened glass is glass formed with a compressive stress layer on the surface of the non-strengthened glass. The strengthened glass can be either physically strengthened glass (such as air-cooled strengthened glass) or chemically strengthened glass. Examples of the organic glass include transparent resins such as polycarbonate, acrylic resin, polyvinyl chloride, and polystyrene. The acrylic resin is, for example, polymethyl methacrylate. In addition, the second glass plate 3 can also be either inorganic glass or organic glass in the same manner as the first glass plate 2.

[0025] The first glass plate 2 is formed to bulge outward toward the vehicle exterior. As the bending forming of the first glass plate 2, gravity forming, pressure forming, or the like can be used. When the first glass plate 2 is physically strengthened glass, the glass surface can be strengthened by rapidly cooling the uniformly heated glass plate starting from a temperature near the softening point during the bending forming process, and generating 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, the glass surface can be strengthened by generating compressive stress on the glass surface using an ion exchange method or the like after the bending forming. In addition, the second glass plate 3 can also be formed to bulge outward toward the vehicle exterior in the same manner as the first glass plate 2.

[0026] The first glass plate 2 is disposed at a position more toward the vehicle exterior than the second glass plate 3. Therefore, in order to suppress abrasions caused by flying stones, it has a thickness of 1.8 mm or more. From the viewpoints of lightweight and formability, the thickness of the first glass plate 2 is 3.0 mm or less. The thickness of the first glass plate 2 can be fixed or can vary according to the position.

[0027] The second glass plate 3 is disposed at a position more toward the vehicle interior than the first glass plate 2. Therefore, it can be thinner than the first glass plate 2. From the viewpoint of operability, the thickness of the second glass plate 3 is 0.3 mm or more. From the viewpoints of lightweight and formability, the thickness of the second glass plate 3 is 2.3 mm or less. The thickness of the second glass plate 3 can be fixed or can vary according to the position.

[0028] The intermediate layer 4 includes an adhesive layer 41 that bonds the first glass plate 2 and the second glass plate 3. The adhesive layer 41 is formed of a conventional resin such as a thermoplastic resin like polyvinyl butyral resin (PVB), ethylene-vinyl acetate copolymer resin (EVA), or cycloolefin polymer (COP). The adhesive layer 41 exhibits adhesiveness when heated.

[0029] The adhesive layer 41 can be either a single-layer structure or a multi-layer structure. The adhesive layer 41 can also have functions other than adhesion. For example, the adhesive layer 41 can have one or more selected from a sound insulation layer, a colored transparent layer, an ultraviolet ray blocking layer, an infrared ray blocking layer, and the like.

[0030] From the viewpoint of adhesiveness, the thickness of the adhesive layer 41 is, for example, 0.5 mm or more. From the viewpoints of lightweight and operability, the thickness of the adhesive layer 41 is, for example, 3 mm or less. The thickness of the adhesive layer 41 can be fixed or can vary according to the position. For example, when the image of the head-up display is projected onto the window glass 1, in order to suppress ghosting, the thickness of the adhesive layer 41 becomes thicker from the lower side to the upper side. The adhesive layer 41 is formed in a wedge shape, and its wedge angle is, for example, 1.0 mrad or less.

[0031] The manufacturing method of the window glass 1 includes the following steps (A) to (C). (A) A laminate is produced by laminating a first glass plate 2 and a second glass plate 3 via an adhesive layer 41. (B) The laminate is placed inside a rubber bag, and while decompressing the inside of 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 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 heat-pressed at a pressure of 0.6 MPa to 1.3 MPa while being heated at, for example, 100°C to 150°C. The heat-pressing is performed using an autoclave, for example. Additionally, the manufacturing method of the window glass 1 may be a conventional method and may not include the step (C) described above.

[0032] The window glass 1 is used, for example, as a windshield of a vehicle. In this case, an adhesive (not shown) for bonding the window glass 1 to the vehicle body is applied to the peripheral portion of the window glass 1. The adhesive is, for example, polyurethane. In order 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 a light-shielding layer 5 is formed or a region where the adhesive layer 41 is colored.

[0033] The light-shielding layer 5 may also be formed Figure 1 as shown, on the entire periphery of the window glass 1. The light-shielding layer 5 is formed, for example, by firing a paste of black ceramic. The paste of black ceramic is applied to the first glass plate 2 or the second glass plate 3 and fired while the first glass plate 2 or the second glass plate 3 is bent and formed. Additionally, the light-shielding layer 5 may also be formed by firing a colored organic ink.

[0034] The light-shielding layer 5 is formed, for example, on two of the first surface 11, the second surface 12, the third surface 13, and the fourth surface 14 of the window glass 1, namely, the second surface 12 and the fourth surface 14. The first surface 11 is the main surface of the first glass plate 2 facing the outside of the vehicle. The second surface 12 is the main surface of the first glass plate 2 facing the inside of the vehicle. The third surface 13 is the main surface of the second glass plate 3 facing the outside of the vehicle. The fourth surface 14 is the main surface of the second glass plate 3 facing the inside of the vehicle. Additionally, the light-shielding layer 5 may also be formed on only one of the second surface 12 and the fourth surface 14.

[0035] 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 also have, for example, one or more selected from a water-repellent layer, an ultraviolet ray cut-off layer, an infrared ray cut-off layer, a heat-insulating layer, and a colored transparent layer, etc. The heat-insulating layer has the function of suppressing radiative heat transfer. The colored transparent layer has an anti-glare function of reducing the visible light transmittance. The arrangement of these functional layers can be on the outside or inside of the window glass 1.

[0036] In addition, the window glass 1 serves as the windshield of the vehicle in the present embodiment, but it may also serve as the rear window glass or the side window glass.

[0037] The second glass plate 3 has an information acquisition area 31. The information acquisition area 31 is an area where the information acquisition device 9 acquires outdoor information, that is, information outside the vehicle. The first glass plate 2 may also have an information acquisition area 21 in the same manner as the second glass plate 3. The information acquisition area 21 of the first glass plate 2 and the information acquisition area 31 of the second glass plate 3 are substantially the same. Therefore, hereinafter, only the information acquisition area 31 of the second glass plate 3 will be described, and the description of the information acquisition area 21 of the first glass plate 2 will be omitted.

[0038] 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 by 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 a LiDAR (Light Imaging Detection and Ranging). The LiDAR irradiates laser light, receives the reflected light from the object, and measures the distance and direction to the object. The LiDAR scans the laser light throughout the information acquisition area 31.

[0039] The information acquisition area 31 is, as Figure 1 shown, for example, an opening of the light shielding layer 5, and is surrounded by the light shielding layer 5 on four sides (top, bottom, left, and right). The light shielding layer 5 includes, for example, a frame portion 51 and a protruding portion 52 that protrudes downward from the upper edge of the frame portion 51. The protruding portion 52 is, for example, trapezoidal. The information acquisition area 31 is provided in the protruding portion 52. In the present embodiment, the information acquisition area 31 is surrounded by the light shielding layer 5 on four sides (top, bottom, left, and right), but it may also be surrounded by three sides (top, left, and right), that is, the bottom side is open.

[0040] The information acquisition area 31 is, as Figure 3 shown, trapezoidal in 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 part of a curve, and a shape in which the upper side 32 and the lower side 33 are not completely parallel but 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 lateral direction, and the Z-axis direction orthogonal to the lateral direction is the longitudinal direction. In addition, the Y-axis direction is the thickness direction. The positive side of the Y-axis direction is the vehicle interior side, and the negative side of the Y-axis direction is the vehicle exterior side.

[0041] The intermediate layer 4 has a heating wire 42 disposed in the information acquisition area 31 as a heating member. The heating wire 42 generates heat by supplying electric power, and removes fog or ice adhering to the information acquisition area 31.

[0042] The heating wire 42 can, for example, cross the information acquisition area 31 in the lateral direction, and a plurality of heating wires 42 are provided at intervals in the longitudinal direction. The heating wire 42 can also be likeFigure 7 As shown, it extends vertically through the information acquisition area 31 in the longitudinal direction, and a plurality of them are arranged at intervals in the transverse direction. The heating wire 42 can also be configured in a mesh shape. That is, it can be set as a heating wire extending in the longitudinal direction and a heating wire extending in the transverse direction. The mesh shape is not limited to a quadrilateral, and can be, for example, a triangle, a hexagon, a circle, etc. In addition, the mesh shape can also be irregular.

[0043] The heating wire 42 can be a straight line, but in order to suppress the generation of glare, it can also be a wavy line such as a sine curve. Glare refers to the phenomenon of seeing striped light, which is caused by the diffraction and interference of light. If the phases of adjacent multiple heating wires 42 are staggered, the generation of glare can be further suppressed. In addition, the period of the heating wire 42 can also change in the middle of the first bus bar 43 to the second bus bar 44.

[0044] 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 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 can be formed of the same material as the first bus bar 43 and the second bus bar 44, or can be integrally formed without using a conductive adhesive such as solder.

[0045] In addition, the heating member of the intermediate layer 4 is a linear heating wire 42 in this embodiment, but it can also be planar. For example, the intermediate layer 4 can include a transparent conductive film as the heating member. Specific examples of the transparent conductive film include indium tin oxide film (ITO film), a thin film of silver or silver alloy, etc.

[0046] The intermediate layer 4 has a first bus bar 43 that supplies a first potential to one end portion 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 portion of the heating wire 42. Either the first potential or the second potential can be higher. The first bus bar 43 and the second bus bar 44 apply a voltage to the heating wire 42. As a result, current is supplied to the heating wire 42 to generate Joule heat.

[0047] As Figure 3 shown, the first bus bar 43 has: an inclined portion 43a formed along the side 34 of the trapezoidal information acquisition area 31, a parallel portion 43b formed along the upper side 32 of the information acquisition area 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 the conductor 63a of the first electrical connector 63 described later.

[0048] The second bus bar 44 also has: an inclined portion 44a formed along the side 35 of the trapezoidal information acquisition area 31, a parallel portion 44b formed along the upper side 32 of the information acquisition area 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 a conductor 64a of a second electrical connector 64 described later.

[0049] The first bus bar 43 and the second bus bar 44 have a lower resistance than the heating wire 42 and, unlike the heating wire 42, hardly generate heat. The area surrounded by the first bus bar 43, the second bus bar 44, and the heating wires 42 at both ends among the multiple heating wires 42, for example, the area surrounded by the thick line of Figure 3 is the heating area H heated by the heating wire 42. The heating area 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.

[0050] In addition, as Figure 7 shown, the heating area H can also be surrounded by the parallel portion 43b of the first bus bar 43, the parallel portion 44b of the second bus bar 44, the left heating wire 42, and the right heating wire 42. The first bus bar 43 has a parallel portion 43b formed along the upper side 32 of the information acquisition area 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 a conductor 63a of a first electrical connector 63 described later. The second bus bar 44 has a parallel portion 44b formed along the lower side 33 of the information acquisition area 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 a conductor 64a of a second electrical connector 64 described later.

[0051] In a top view (Y-axis direction view), the shape of the heating area H is, for example, Figure 3 the trapezoid shown or Figure 7 the rectangle shown. In the top view, the area of the heating area H is of the same order as the area of the information acquisition area 31. The area B of the heating area H is, for example, 1500 mm 2 to 36000 mm 2 , preferably 2500 mm 2 to 30000 mm 2 , and more preferably 4000 mm 2 to 30000 mm 2 .

[0052] In the top view, the shape of the heating area H can also be Figure 3 the trapezoid shown or Figure 7The shape other than the rectangle shown may be, for example, a U-shape as shown in FIG. 13 of Patent Document 1. 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.

[0053] In addition, as described above, the heat generating member may also be planar. When the heat generating member is planar, the heating region heated by the heat generating member is an area surrounded by the first bus bar 43, the second bus bar 44, and the periphery of the heat generating member.

[0054] The first bus bar 43 is formed, for example, by firing a noble metal paste such as silver paste, or formed of a metal strip such as a copper strip. The first bus bar 43 may be formed of flat braided copper wire. The second bus bar 44 may be formed in the same manner as the first bus bar 43.

[0055] The material of the first bus bar 43 is the same as that of the heating wire 42, and is a pure metal containing a metal selected from 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 also be a conductive organic polymer. The material of the second bus bar 44 is the same as that of the first bus bar 43.

[0056] As Figure 5 shown, the intermediate layer 4 may further contain 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 in a state of being supported by the base film 45.

[0057] By means of the base film 45, the operability of the heating wire 42 and the like is improved. The base 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 face the second glass plate 3. The base film 45 is in contact with the second glass plate 3.

[0058] In addition, a second adhesive layer (not shown) having a larger area than the base film 45 may be disposed between the base film 45 and the second glass plate 3. The second adhesive layer is configured in the same manner as the adhesive layer 41. By means of the second adhesive layer, peeling between the base film 45 and the second glass plate 3 can be reliably prevented. The base film 45 is disposed between the adhesive layer 41 and the second adhesive layer.

[0059] The base film 45 is formed of a transparent resin, for example, formed of the same material as the adhesive layer 41. However, the material of the base film 45 may not be a material that exhibits adhesiveness by heating, and may be, for example, polyethylene terephthalate (PET) or the like.

[0060] The peripheral edge of the base material film 45 is disposed at a position closer to the inside than the peripheral edge of the adhesive layer 41. Since the area of the adhesive layer 41 is larger than that of the base material film 45, even when the base material film 45 has no 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, like the adhesive layer 41, have an area larger than that of the base material film 45.

[0061] In addition, the arrangement of the first bus bar 43 and the conductor 63a of the first electrical connector 63 can be reversed, and the conductor 63a can 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 can be reversed, and the conductor 64a can be disposed between the second bus bar 44 and the base material film 45. In addition, as described above, the base material film 45 can be disposed between the adhesive layer 41 and the second adhesive layer.

[0062] The intermediate layer 4 includes the base material film 45 in the present embodiment, but may not include the base material 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. In addition, in this case, the heating wire 42, the first bus bar 43, and the second bus bar 44 can also be disposed between the adhesive layer 41 and the second adhesive layer.

[0063] As Figure 3 shown, 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 and protrudes to the outside of the intermediate layer 4, and is connected to the vehicle wiring harness and the first bus bar 43.

[0064] The first electrical connector 63 includes a conductor 63a and an insulator 63b covering the conductor 63a. The conductor 63a supplies a first potential from the vehicle wiring harness to the first bus bar 43. The conductor 63a is formed of a metal strip such as a Cu strip, for example. The insulator 63b is formed of a resin, for example.

[0065] 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 dimensionless. The cross-section of the conductor 63a is a cross-section orthogonal 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.

[0066] If B / A1 is 5,000 or more, the cross-sectional area A1 of the conductor 63a is small enough, and the bubbles generated inside the laminate in the above step (A) are small. Therefore, through the above step (B) or (C), the bubbles are easily eliminated, and the appearance of the finally obtained window glass 1 is good.

[0067] If B / A1 is less than 200,000, the cross-sectional area A1 of the conductor 63a is large enough, and abnormal heating or disconnection of the conductor 63a is not likely to occur, enabling a large current to be supplied to the heating region H. The heat generation density, i.e., the heat generation per unit area of the heating region H, is, for example, 500 W / m 2 ~2500 W / m 2 and preferably 700 W / m 2 ~2000 W / m 2 .

[0068] B / A1 is preferably 5000 to 200,000, more preferably 15,000 to 200,000, and still more preferably 20,000 to 200,000. A1 is, for example, 0.2 mm 2 ~7.0 mm 2 and preferably 0.3 mm 2 ~6.0 mm 2 . As Figure 7 shown, when the number of the first electrical connectors 63 for heating the heating region H is plural, A1 is the total cross-sectional area of all the conductors 63a for heating the heating region H.

[0069] The cross-section of the conductor 63a is, for example, rectangular, and the ratio (T1 / W1) of the thickness T1 to the width W1 is 0.007 to 0.04. T1 / W1 is dimensionless.

[0070] If T1 / W1 is 0.007 or more, the thickness T1 of the conductor 63a is thick enough, and disconnection caused by bending deformation of the conductor 63a (see, for example, Figure 8 ) need not be worried about, and the workability is good. If T1 / W1 is 0.04 or less, the thickness T1 of the conductor 63a is thin enough, and the bubbles generated inside the laminate in the above step (A) are small. Therefore, through the above step (B) or (C), the bubbles easily disappear, and the appearance of the finally obtained window glass 1 is good.

[0071] T1 / W1 is preferably 0.009 to 0.035, and more preferably 0.009 to 0.012. T1 is, for example, 10×10 -3 mm~400×10 -3 mm, preferably 70×10 -3 mm~200×10 -3 mm. And W1 is, for example, 1 mm~25 mm, and preferably 3 mm~15 mm.

[0072] The window glass 1 further includes 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 and extends out of the intermediate layer 4 to connect to the vehicle wiring harness and the second bus bar 44.

[0073] The second electrical connector 64 includes a conductor 64a and an insulator 64b that coats the conductor 64a. The conductor 64a supplies a second potential from the vehicle's wiring harness to the second bus bar 44. The conductor 64a is formed of a metal strip such as a Cu strip, for example. The insulator 64b is formed of resin, for example.

[0074] 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 dimensionless. The cross-section of the conductor 64a is a cross-section orthogonal to the flow of 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.

[0075] If B / A2 is 5,000 or more, the cross-sectional area A2 of the conductor 64a is small enough, and the bubbles generated inside the laminate in the above step (A) are small. Therefore, through the above step (B) or (C), the bubbles easily disappear, and the appearance of the finally obtained window glass 1 is good. If B / A2 is 200,000 or less, the cross-sectional area A2 of the conductor 64a is large enough, and abnormal heating or disconnection of the conductor 64a does not occur, and a large current can be supplied to the heating region H.

[0076] 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 In addition, although not shown, when the number of the second electrical connectors 64 for heating the heating region H is plural, A2 is the total cross-sectional area of all the conductors 64a for heating the heating region H.

[0077] 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 dimensionless.

[0078] If T2 / W2 is 0.007 or more, the thickness T2 of the conductor 64a is thick enough, and there is no need to worry about disconnection due to bending deformation of the conductor 64a, and the workability is good. If T2 / W2 is 0.04 or less, the thickness T2 of the conductor 64a is thin enough, and the bubbles generated inside the laminate in the above step (A) are small. Therefore, through the above step (B) or (C), the bubbles easily disappear, and the appearance of the finally obtained window glass 1 is good.

[0079] T2 / W2 is preferably 0.009 to 0.035, more preferably 0.009 to 0.012. T2 is, for example, 10×10 -3 mm~400×10 -3mm, preferably 70×10 -3 mm to 200×10 -3 mm. And W2 is, for example, 1 mm to 25 mm, preferably 3 mm to 15 mm.

[0080] The cross-sections of the conductors 63a of the first electrical connector 63 and the conductors 64a of the second electrical connector 64 have the same shape and the same dimensions in the present embodiment, but may have different shapes and may have different dimensions.

[0081] As Figure 2 shown, the first electrical connector 63 and the second electrical connector 64 are arranged at intervals along the peripheral edge 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 peripheral edge of the first glass plate 2, more specifically, along the upper edge of the first glass plate 2.

[0082] As Figure 4 shown, the interval 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, the adhesive layer 41 will be deformed to fill the space between the first electrical connector 63 and the second electrical connector 64 in the above step (B) or (C), and the finally obtained window glass 1 will have fewer internal bubbles. 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, the connection of the first electrical connector 63 or the second electrical connector 64 to the wire on the vehicle body side (such as Figure 8 shown harness 73) is easy. In addition, G is smaller than the lateral width of the heating region H.

[0083] The interval G between the first electrical connector 63 and the second electrical connector 64 is, for example, greater than or equal to the width TW1 of the first electrical connector 63 and greater than or equal to the width TW2 of the second electrical connector 64. If G is greater than or equal to TW1 and TW2, the adhesive layer 41 will be deformed to fill the space between the first electrical connector 63 and the second electrical connector 64 in the above step (B) or (C), and the finally obtained window glass 1 will have fewer internal bubbles. G is preferably 2 times or more of TW1 and 2 times or more of TW2. On the other hand, G is preferably 40 times or less of TW1 and 40 times or less of TW2. If G is 40 times or less of TW1 and 40 times or less of TW2, the connection of the first electrical connector 63 or the second electrical connector 64 to the wire on the vehicle body side is easy. For example, TW1 is 5 mm or less than W1 + 5 mm and TW2 is 5 mm or less than W2 + 5 mm. Preferably, TW1 is 2 mm or less than W1 + 2 mm and TW2 is 2 mm or less than W2 + 2 mm.

[0084] As Figure 8As shown, the first electrical connector 63 is bent into a U shape, for example, along the upper edge of the second glass plate 3, and is connected to the vehicle wiring harness 73 by soldering or the like on the vehicle inner 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. 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 operation of the second glass plate 3 is easy. The radius of curvature of the bent portion of the first electrical connector 63 is, for example, half of the plate thickness of the second glass plate 3. Although not shown, the second electrical connector 64 is also bent into a U shape along the upper edge of the second glass plate 3 and is connected to the vehicle wiring harness by soldering or the like on the vehicle inner 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 plate thickness of the second glass plate 3.

[0085] The peripheral edge of the second glass plate 3 has a cutout 32 with a depth D of 2 mm or less, preferably 1 mm or less, from the peripheral edge of the second glass plate 3 at the position where the first electrical connector 63 is disposed. The cutout 32 may not be provided. The smaller the cutout 32, the smaller the shape difference between the first glass plate 2 and the second glass plate 3, and the smaller the bending difference during bending forming, thereby reducing the risk of cracking and foaming.

[0086] Although not shown, the peripheral edge of the second glass plate 3 may have a cutout with a depth of 2 mm or less, preferably 1 mm or less, from the peripheral edge of the second glass plate 3 at the position where the second electrical connector 64 is disposed, or the cutout may not be provided. The smaller the cutout 32, the smaller the shape difference between the first glass plate 2 and the second glass plate 3, and the smaller the bending difference during bending forming, thereby reducing the risk of cracking and foaming.

[0087] Embodiment

[0088] Hereinafter, the experimental data will be described 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, the window glass was manufactured under the same conditions except for the conditions shown in Table 1. The thickness of the first glass plate is 2 mm, the thickness of the second glass plate is 2 mm, and the thickness of the PVB sheet as the adhesive layer is 0.76 mm. In addition, when viewed from above, the size of the window glass is 1500 mm in width and 1000 mm in length. The heating wire, the first bus bar, and the second bus bar as the heating members are formed by firing silver paste and are arranged Figure 2 and Figure 3As shown. The base film that supports the heating wire or the like is a PVB sheet with a thickness of 0.76 mm. One first electrical connector and one second electrical connector are provided respectively. The first electrical connector and the second electrical connector are arranged at an interval of 10 mm 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, is 1.5 V. The heat generation density in the heating area is 1000 W / m 2 . In addition, the radius of curvature of the portions where the first electrical connector and the second electrical connector are bent along the upper edge of the second glass plate is 1 mm. In Examples 1 to 6, after the window glass was manufactured, the presence or absence of bubbles in the window glass and the durability during energization were investigated. The presence or absence of bubbles was confirmed visually. The durability during energization was evaluated by the presence or absence of abnormal heat generation in the first electrical connector and the second electrical connector. In Table 1, "○" indicates that all 30 window glasses had no abnormal heat generation when 30 window glasses were manufactured, "△" indicates that there was a probability of less than 10% of abnormal heat generation when 30 window glasses were manufactured, and "×" indicates that there was a probability of 10% or more of abnormal heat generation when 30 window glasses were manufactured.

[0089]

Table 1

[0090]

[0091] As can be seen from Table 1, according to Examples 2 to 4, both B / A1 and B / A2 are 5,000 or more and 200,000 or less respectively. Therefore, there are no bubbles inside the window glass, and all 30 window glasses have no abnormal heat generation. According to Example 1, both B / A1 and B / A2 are less than 5,000. Therefore, there are bubbles inside the window glass. In addition, according to Examples 5 and 6, both B / A1 and B / A2 exceed 200,000. Therefore, there is a probability of 10% or more of abnormal heat generation in 30 window glasses.

[0092] In Example 7, a window glass was manufactured under the same conditions as in Example 3, except that the thickness of the second glass plate was changed to 1 mm and the radius of curvature of the portions where the first electrical connector and the second electrical connector were bent along the upper edge of the second glass plate was changed to 0.5 mm. The durability of the window glass manufactured in Example 7 during energization was investigated. As a result, all 30 window glasses had no abnormal heat generation and were evaluated as "〇". In Example 8, a window glass was manufactured under the same conditions as in Example 3, except that the thickness of the second glass plate was changed to 0.8 mm and the radius of curvature of the portions where the first electrical connector and the second electrical connector were bent along the upper edge of the second glass plate was changed to 0.4 mm. The durability of the window glass manufactured in Example 8 during energization was investigated. The results showed that there was a probability of less than 10% of abnormal heat generation due to wire breakage at the first electrical connector and the second electrical connector in 30 window glasses, and it was evaluated as "△".

[0093] The window glass of the present invention has been described above, but the present invention is not limited to the above-described embodiments and the like. Various changes, corrections, substitutions, additions, deletions, and combinations can be made within the scope described in the claims. They naturally also belong to the technical scope of the present invention.

[0094] For example, the window glass is installed on a vehicle in the above-described embodiment, but it can also be installed on a building.

[0095] 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.

[0096] Symbol Explanation

[0097] 1 Window glass

[0098] 2 First glass plate

[0099] 21 Information acquisition area

[0100] 3 Second glass plate

[0101] 31 Information acquisition area

[0102] 4 Intermediate layer

[0103] 42 Electric heating wire (heating member)

[0104] 43 First bus bar

[0105] 44 Second bus bar

[0106] 63 First electrical connector

[0107] 63a Conductor

[0108] 64 Second electrical connector

[0109] 64a Conductor

[0110] H Heating area.

Claims

1. A window glass, comprising: a first glass plate having 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, wherein 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 window glass further includes: a first electrical connector connected to the first bus bar inside the intermediate layer and protruding to the outside of the intermediate layer, and a second electrical connector connected to the second bus bar inside the intermediate layer and protruding 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 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.

2. The window glass according to claim 1, wherein The cross-sectional shape of the conductor of the first electrical connector is rectangular, and the ratio of the thickness to the width is 0.007 to 0.04, The cross-sectional shape of the conductor of the second electrical connector is rectangular, and the ratio of the thickness to the width is 0.007 to 0.

04.

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

4. The window glass according to claim 1 or 2, wherein, The first electrical connector and the second electrical connector are arranged at intervals along the periphery of the second glass plate, the interval between the first electrical connector and the second electrical connector is greater than or equal to the width of the first electrical connector and greater than or equal to the width of the second electrical connector.

5. The window glass according to claim 1 or 2, wherein The second glass plate is disposed 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 cut 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 cut.

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