JP6736448B2 - Laminated glass - Google Patents

Description

The present invention relates to laminated glass.

On a cold day or in cold regions, the windshield of a car may become cloudy, which hinders driving. Therefore, various methods for removing the fogging of the windshield have been proposed. For example, Patent Document 1 discloses disposing a bus bar and a heating wire inside a windshield and removing fogging by the heat generated by the busbar and the heating wire.

JP, 2012-14945, A

By the way, Patent Document 1 describes that the power supply voltage of a general vehicle is 12V. However, in recent years, from the viewpoint of energy saving, a power supply voltage higher than 12 V is planned (for example, 48 V). When the power supply voltage is increased as described above, the heating wire used so far has an excessively large amount of heat generation per unit length, which may cause the glass to break.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a laminated glass capable of suppressing the amount of heat generated by a heating wire even when the power supply voltage is high.

The laminated glass according to the present invention has a rectangular first glass plate having a first side and a second side facing the first side, and the first glass plate is arranged to face the first glass plate. A second glass plate having substantially the same shape as the above, and an intermediate film arranged between the first glass plate and the second glass plate, wherein the intermediate film is on the first side side or the second side side. Bus bar extending along the end of the first bus bar, a second bus bar extending along the end of the first side or the second side, and in parallel so as to connect the first bus bar and the second bus bar. A plurality of heating wires arranged, and at least one of the plurality of heating wires changes at least one of the heating wires extending between the first bus bar and the second bus bar. It has two folded portions. Here, the "folded portion" is a portion that reciprocates in a direction substantially perpendicular to the extending direction of the bus bar.

In the above laminated glass, each heating wire may have a heating value per unit area of 200 to 1000 W/m ² .

In the laminated glass, the first bus bar is arranged along an end portion on the first side side, the second bus bar is arranged along an end portion on the second side side, and the plurality of heating wires are arranged. At least one of them may have at least two folded-back portions between the first bus bar and the second bus bar that change the extending direction of the heating wire.

In the above laminated glass, the first bus bar and the second bus bar are arranged along the same end of either the first side end or the second side end, and the plurality of heating wires At least one of them may have at least one folded-back portion between the first bus bar and the second bus bar, which changes the extending direction of the heating wire.

The laminated glass may further include at least one relay bus bar arranged at a position different from that of the first bus bar and the second bus bar along the end on the first side side or the second side side, and the plurality of relay bus bars may be provided. The heating wire may be connected to the second bus bar from the first bus bar via at least one of the relay bus bars.

In the above laminated glass, the plurality of heating wires include at least one first heating wire and at least one second heating wire formed of a material having higher resistance than the first heating wire, The length of one heating wire may be longer than that of the second heating wire.

In each of the above laminated glasses, a shielding layer that is laminated on at least one of the first glass plate and the second glass plate and shields a visual field from the vehicle exterior or vehicle interior is further provided, and the first busbar and the second busbar are provided. May be covered by the shielding layer.

In each of the above laminated glasses, a laminated layer that is laminated on at least one of the first glass plate and the second glass plate and shields a visual field from the vehicle exterior or vehicle interior is provided, and the first bus bar and the second bus bar are provided. , And at least one folded portion may be covered with the shielding layer.

In each of the above laminated glasses, the intermediate film may include at least a sheet-shaped base material that supports the plurality of heating wires.

In each of the laminated glasses, a heating layer is formed by the first bus bar, the second bus bar, the plurality of heating wires, and the base material, and the intermediate film includes a pair of adhesive layers that sandwich the heating layer. , Can be further provided.

In each of the laminated glasses, the first bus bar, the second bus bar, and the plurality of heating wires can be integrally formed of the same material.

In each of the above laminated glasses, the line width of the heating wire may be 500 μm or less.

In each of the above laminated glasses, a voltage of 48 V can be applied to the plurality of heating wires.

According to the present invention, the amount of heat generated by the heating wire can be suppressed even when the power supply voltage is high.

It is a front view of 1st Embodiment of the laminated glass which concerns on this invention. It is the sectional view on the AA line of FIG. It is a side view of a furnace through which a mold passes. It is a top view of a shaping die. It is a front view which shows the other example of the laminated glass of FIG. It is a front view of 2nd Embodiment of the laminated glass which concerns on this invention. It is a front view of 3rd Embodiment of the laminated glass which concerns on this invention. It is a front view of 4th Embodiment of the laminated glass which concerns on this invention. It is a front view which shows the other example of the laminated glass which concerns on this invention. It is sectional drawing which shows the other example of an intermediate film. It is sectional drawing which shows the example of the other laminated glass which concerns on this invention.

<A. First Embodiment>
Hereinafter, a first embodiment in which a laminated glass according to the present invention is applied to a windshield will be described with reference to the drawings. FIG. 1 is a plan view of a windshield according to this embodiment, and FIG. 2 is a sectional view of FIG. As shown in FIGS. 1 and 2, the windshield according to the present embodiment has an outer glass plate (second glass plate) 1, an inner glass plate (first glass plate) 2, and a space between these glass plates 1 and 2. The intermediate film 3 arranged in the. Further, notches 21 and 22 are formed at the upper end and the lower end of the inner glass plate 2, respectively, and the connection members 41 and 42 extending from the intermediate film 3 are exposed at the notches 21 and 22, respectively. doing. Hereinafter, each member will be described.

<1. Overview of laminated glass>
<1-1. Glass plate>
Each of the glass plates 1 and 2 is formed in a rectangular shape in which the lower side (second side) 12 is longer than the upper side (first side) 11, and as described above, the upper and lower ends of the inner glass plate 2 are formed. Arc-shaped notches are formed in the respective portions. Below, the notch formed in the upper end of the inner glass plate 2 is referred to as a first notch 21, and the notch formed in the lower end is referred to as a second notch 22. Further, as each of the glass plates 11 and 12, a known glass plate can be used, and heat-absorbing glass, general clear glass, green glass, or UV green glass can be used. However, these glass plates 11 and 12 need to realize visible light transmittance in accordance with the safety standard of the country in which the automobile is used. For example, the outer glass plate 11 can secure the necessary solar radiation absorptance, and the inner glass plate 12 can adjust the visible light transmittance so as to satisfy the safety standard. Below, an example of composition of clear glass, heat ray absorption glass, and soda lime type glass is shown.

(Clear glass)
SiO _2: 70~73 mass%
Al ₂ O _3: 0.6~2.4 wt%
CaO: 7 to 12 mass%
MgO: 1.0-4.5 mass%
R ₂ O: 13 to 15 mass% (R is an alkali metal)
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.08~0.14 wt%

(Heat absorption glass)
The composition of the heat-absorbing glass, for example, based on the composition of the clear glass, the proportion of the total iron oxide in terms of _{Fe 2 O 3 (T-Fe} 2 O 3) and 0.4 to 1.3 wt%, CeO ₂ ratio as 0-2 mass%, the proportion of TiO ₂ and 0 to 0.5 wt%, framework component of the glass (mainly, SiO ₂ and Al ₂ O ₃₎ to T-Fe ₂ O _3, CeO _The composition can be obtained by reducing the increments of ₂ and TiO ₂ .

(Soda-lime glass)
SiO _2: 65~80 mass%
Al ₂ O ₃ : 0-5% by mass
CaO: 5 to 15 mass%
MgO: 2 mass% or more NaO: 10-18 mass%
K ₂ O: 0-5% by mass
MgO+CaO: 5-15% by mass
Na ₂ O+K ₂ O: 10 to 20 mass%
SO _3: 0.05 to 0.3 mass%
B ₂ O _3: 0~5 wt%
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.02~0.03 wt%

As described above, the glass plates 1 and 2 are formed in a rectangular shape, but the ratio of the lengths of the upper side 11 and the lower side 12 may be, for example, 1:1.04 to 1:1.5. it can. For example, when the upper side is 1200 mm, the lower side can be 1250 to 1800 mm. Specifically, the upper side can be 1195 mm and the lower side can be 1435 mm. The ratio described above is a ratio on a two-dimensional plane when the windshield is projected from the front.

That is, although FIG. 1 shows an example in which the lower side 12 is long, the present invention is also applicable to a windshield having a long upper side 11. For example, the windshield of a small car for one person may have a lower side of 350 to 450 mm when the upper side is 500 mm. Specifically, the upper side can be 500 mm and the lower side can be 425 mm.

The thickness of the laminated glass according to the present embodiment is not particularly limited, but from the viewpoint of weight reduction, the total thickness of the outer glass plate 1 and the inner glass plate 2 is preferably set to 2.4 to 4.6 mm. The thickness is more preferably 2.6 to 3.4 mm, particularly preferably 2.7 to 3.2 mm. As described above, in order to reduce the weight, it is necessary to reduce the total thickness of the outer glass plate 1 and the inner glass plate 2. Therefore, the thickness of each glass plate is not particularly limited, For example, the thicknesses of the outer glass plate 11 and the inner glass plate 12 can be determined as follows.

The outer glass plate 1 is mainly required to have durability and impact resistance against external obstacles. For example, when this laminated glass is used as a windshield of an automobile, impact resistance performance against flying objects such as pebbles is required. is necessary. On the other hand, the larger the thickness, the more the weight increases, which is not preferable. From this point of view, the thickness of the outer glass plate 1 is preferably 1.0 to 3.0 mm, more preferably 1.6 to 2.3 mm. Which thickness to use can be determined according to the application of glass.

Although the thickness of the inner glass plate 2 can be made equal to that of the outer glass plate 1, for example, the thickness of the inner glass plate 2 can be made smaller than that of the outer glass plate 11 in order to reduce the weight of the laminated glass. Specifically, considering the strength of the glass, it is preferably 0.6 to 2.0 mm, more preferably 0.8 to 1.8 mm, and 0.8 to 1.6 mm. Particularly preferred. Further, it is preferably 0.8 to 1.3 mm. For the inner glass plate 2, which thickness is adopted can be determined according to the application of the glass.

Further, the outer glass plate 1 and the inner glass plate 2 according to this embodiment may have a curved shape. However, when each of the glass plates 1 and 2 has a curved shape, it is said that the sound insulation performance deteriorates as the amount of debris increases. The double amount is the amount that indicates the bending of the glass plate. When the straight line L connecting the center of the upper side and the center of the lower side of the glass plate is set, the largest distance between the straight line L and the glass plate is determined. It is defined as the amount of doublet D.

Further, in the curved glass plate, there is no great difference in sound transmission loss (STL: Sound Transmission Loss) in the range of the debris amount of 30 to 38 mm, but as compared with the flat glass plate, the frequency band of 4000 Hz or less. It can be seen that the sound transmission loss is reduced. Therefore, when producing a curved glass plate, it is preferable that the amount of debris is small. Specifically, the amount of debris is preferably less than 30 mm, more preferably less than 25 mm, and particularly preferably less than 20 mm.

Here, an example of a method of measuring the thickness when the glass plate is curved will be described. First, the measurement positions are two positions above and below the center line that extends vertically in the horizontal center of the glass plate. The measuring device is not particularly limited, but a thickness gauge such as SM-112 manufactured by Teclock Co., Ltd. can be used, for example. At the time of measurement, the curved surface of the glass plate is placed on a flat surface, and the edge of the glass plate is sandwiched between the thickness gauges for measurement.

<1-2. Intermediate film>
Next, the intermediate film 3 will be described. The intermediate film 3 is composed of three layers including a heat generating layer 31 and a pair of adhesive layers 32 and 33 that sandwich the heat generating layer 31. Hereinafter, the adhesive layer arranged on the outer glass plate 1 side is referred to as a first adhesive layer 32, and the adhesive layer arranged on the inner glass plate 2 side is referred to as a second adhesive layer 33.

<1-2-1. Heating layer>
First, the heat generating layer 31 will be described. The heat generating layer 31 includes a sheet-shaped base material 311, a first bus bar 312, a second bus bar 313, and a plurality of heating wires 6 arranged on the base material 311. The base material 311 can be formed in a substantially rectangular shape so as to correspond to the glass plates 1 and 2, but the base material 311 does not necessarily have to have the same shape as the glass plates 1 and 2, May have a small shape. For example, as shown in FIG. 1, it may be shorter than the length between the notches 21 and 22 in the vertical direction so as not to interfere with the notches 21 and 22 of the inner glass plate 2. Also, the length of the base material 311 in the left-right direction can be made shorter than the width of both the glass plates 1 and 2.

The first bus bar 312 is formed so as to extend along the upper side of the base material 311. On the other hand, the second bus bar 313 is formed so as to extend along the lower side of the base material 311, but is formed longer than the first bus bar 312. However, each of the bus bars 312 and 313 is arranged so as not to be exposed from the above-mentioned cut-out portions 21 and 22 when the intermediate film 3 is sandwiched between the glass plates 1 and 2, rather than the cut-out portions 21 and 22. It is placed inside. The upper and lower widths of the bus bars 312 and 313 are preferably, for example, 5 to 50 mm, more preferably 10 to 30 mm. This is because if the width of the bus bars 312 and 313 is smaller than 5 mm, a heat spot phenomenon may occur and heat may be generated higher than the heating wire, while if the width of the bus bars 312 and 313 is larger than 50 mm, the bus bars 312 and 313 may be heated. This may hinder the visual field. In addition, the bus bars 312 and 313 do not have to be accurately formed along the base material 311. That is, it is not necessary to be completely parallel to the edge of the base material 311, and it may be curved or the like.

The plurality of heating wires 6 are arranged in parallel so as to connect both bus bars 312 and 313. Each heating wire 6 is composed of three parts and two folded parts. That is, the first portion 61 extending from the first bus bar 312 to a position close to the second bus bar 313, the lower end portion of the first portion 61 extending upward through the first folded portion 64, and the position close to the first bus bar 312. The second portion 62 extends up to and the third portion 63 extends downward from the upper end of the second portion 62 via the second folded portion 65 and is connected to the second bus bar 313. The plurality of heating wires 6 formed in this way are arranged in the left-right direction of both bus bars 312 and 313 at a predetermined interval. Further, the line width of each heating wire 6 is preferably 3 to 500 μm, more preferably 5 to 20 μm, and particularly preferably 8 to 10 μm.

Further, the distance between the adjacent heating wires 6 and the distance between the adjacent portions in one heating wire 6 in the left-right direction are preferably 1 to 4 mm, and more preferably 1.25 to 3 mm. Particularly preferably, it is 1.25 to 2.5 mm.

In addition, each heating wire 6 can be formed in various shapes such as a corrugated shape as well as a linear shape. In particular, by forming each heating wire 6 in a sinusoidal shape, the heat distribution becomes uniform, and the light beam is optically suppressed to prevent the heating wire 6 from obstructing the field of view of the windshield. it can. Further, although the folded-back portions 64 and 65 are formed by combining acute-angled corner portions, they may be formed in an arc shape. Note that the sinusoidal shape does not need to have a constant amplitude or wavelength like a sine wave, but refers to a waveform in which the amplitude and wavelength are random.

The width of the heating wire 6 can be measured, for example, by using a microscope such as VHX-200 (manufactured by Keyence Corporation) 1000 times. Note that the amount of heat generation actually affects the cross-sectional area of the heating wire 6, but since the width and the cross-sectional area are technically synonymous, they may be used as physical properties without particular distinction. Further, the smaller the width, the more difficult it is to visually recognize, and it is suitable for the windshield according to the present embodiment.

Next, the material of the heat generating layer 31 will be described. The base material 311 is a transparent film that supports both the bus bars 312 and 313 and the heating wire 6, and the material thereof is not particularly limited, and examples thereof include polyethylene terephthalate, polyethylene, polymethyl methacrylate, polyvinyl chloride, polyester, and polyolefin. , Polycarbonate, polystyrene, polypropylene, nylon and the like. Both bus bars 312 and 313 and the heating wire 6 can be formed of the same material, and can be formed of various materials such as copper (or tin-plated copper), tungsten, and silver.

Subsequently, a method of forming both bus bars 312 and 313 and the heating wire 6 will be described. Both of these bus bars 312 and 313 and the heating wire 6 can be formed by arranging a thin wire (such as a wire) formed in advance on the base material 311. In particular, in order to make the width of the heating wire 6 smaller. The heating wire 6 can be formed by forming a pattern on the base material 311. The method is not particularly limited, but it can be formed by various methods such as printing, etching and transfer. At this time, the bus bars 312 and 313 and the heating wire 6 can be formed separately or can be integrally formed. In addition, "integral" means that there is no discontinuity (seamless) between materials and that there is no interface.

Further, both bus bars 312 and 313 are formed on the base material 311, and the base material 311 for the heating wire 6 is left, and the base material 311 corresponding to the bus bars 312 and 313 is peeled and removed. After that, a heating wire can be placed on the substrate between the two bus bars.

In particular, when etching is adopted, the following can be taken as an example. First, a metal foil is dry-laminated on the base material 311 via a primer layer. As the metal foil, for example, copper can be used. Then, by performing a chemical etching process using a photolithography method on the metal foil, both bus bars 312 and 313 and the plurality of heating wires 6 can be integrally formed on the base material 311 by patterning. In particular, when the line width of the heating wire 6 is reduced (for example, 15 μm or less), it is preferable to use a thin metal foil, and a thin metal layer (for example, 5 μm or less) is deposited on the base material 311 by vapor deposition or sputtering. After forming, patterning may be performed by photolithography.

<1-2-2. Adhesive layer>
Both adhesive layers 32 and 33 are sheet-like members for sandwiching the heat generating layer 31 and adhering it to the glass plates 1 and 2. Both adhesive layers 32 and 33 are formed to have the same size as both glass plates 1 and 2, but both adhesive layers 32 and 32 are provided at positions corresponding to the notches 21 and 22 of the inner glass plate 2. Notches having the same shape are formed. The adhesive layers 32 and 33 can be formed of various materials, for example, polyvinyl butyral resin (PVB), ethylene vinyl acetate (EVA), or the like. In particular, polyvinyl butyral resin is preferable because it has excellent adhesion resistance to each glass plate and also excellent penetration resistance. A surface active agent layer may be provided between the adhesive layers 32 and 33 and the heat generating layer 31. The surface of both layers can be modified by such a surfactant, and the adhesive strength can be improved.

<1-2-3. Thickness of interlayer film>
The total thickness of the intermediate film 3 is not particularly limited, but is preferably 0.3 to 6.0 mm, more preferably 0.5 to 4.0 mm, and 0.6 to 2.0 mm. It is particularly preferable that Moreover, the thickness of the base material 311 of the heat generating layer 31 is preferably 0.01 to 2.0 mm, and more preferably 0.03 to 0.6 mm. On the other hand, the thickness of each adhesive layer 32, 33 is preferably larger than the thickness of the heat generating layer 31, and specifically, it is preferably 0.1 to 2.0 mm, and 0.1 to 1.0 mm. It is more preferable that there is. In order to bring the second adhesive layer 33 and the base material 311 into close contact with each other, it is preferable that the bus bars 312 and 313 and the heating wire 6 sandwiched therebetween have a thickness of 3 to 20 μm.

The thickness of the heat generating layer 31 and the adhesive layers 32 and 33 can be measured as follows, for example. First, the cross section of the laminated glass is enlarged and displayed 175 times with a microscope (for example, VH-5500 manufactured by Keyence Corporation). Then, the thicknesses of the heat generating layer 31 and the adhesive layers 32 and 33 are visually identified and measured. At this time, in order to eliminate visual variations, the number of measurements is set to 5 and the average value thereof is taken as the thickness of the heat generating layer 31 and the adhesive layers 32 and 33.

The thicknesses of the heat generating layer 31 and the adhesive layers 32 and 33 of the intermediate film 3 do not need to be constant over the entire surface, and may be wedge-shaped for laminated glass used in a head-up display, for example. In this case, the thicknesses of the heat generating layer 31 and the adhesive layers 32 and 33 of the intermediate film 3 are measured at the smallest thickness, that is, the lowermost side of the laminated glass. When the intermediate film 3 has a wedge shape, the outer glass plate 1 and the inner glass plate 2 are not arranged in parallel, but such an arrangement is also included in the glass plate in the present invention. That is, in the present invention, for example, the outer glass plate 1 and the inner glass plate 2 when using the intermediate film 3 including the heat generating layer 31 and the adhesive layers 32 and 33, the thickness of which increases at a rate of change of 3 mm or less per 1 m Including placement.

<1-3. Connection material>
Next, the connecting material will be described. The connecting members 41 and 42 are for connecting the bus bars 312 and 313 to the connecting terminals (anode terminal or cathode terminal: not shown), and are formed of a conductive material in a sheet shape. Then, a voltage higher than 12V, for example, a power supply voltage of 48V is applied to this connection terminal. Hereinafter, the connecting material connected to the first bus bar 312 will be referred to as a first connecting material 41, and the connecting material connected to the second bus bar 313 will be referred to as a second connecting material 42. Further, since both connecting members 41, 42 have the same configuration, the first connecting member 41 will be mainly described below.

The first connecting member 41 is formed in a rectangular shape, and is sandwiched between the first bus bar 312 and the second adhesive layer 33. Then, it is fixed to the first bus bar 312 by a fixing material 5 such as solder. As the fixing material 5, it is preferable to use, for example, a solder having a low melting point of 150° C. or lower so that it can be fixed at the same time by an autoclave when assembling a windshield described later. Further, the first connecting member 41 extends from the first bus bar 312 to the upper edge of the outer glass plate 1 and is exposed from the first cutout portion 21 formed in the inner glass plate 2. Then, at this exposed portion, the connection terminal to which the cable extending to the power source is connected is connected by a fixing material such as solder. As described above, the connecting terminals are fixed to the portions of the inner glass plate 2 exposed from the notches 21 and 22 without protruding from the end portions of the both glass plates 1 and 42. It has become. Since both connecting members 41, 42 are made of a thin material, they can be bent and then fixed at their ends to the bus bar 312 by the fixing member 5, as shown in FIG.

<1-4. Shielding layer>
As shown in FIG. 1, a shielding layer 7 is laminated on the peripheral edge of this laminated glass with a dark ceramic such as black. This shielding layer 7 shields the visual field from inside or outside the vehicle, and is laminated along four sides of the laminated glass. Both bus bars 312 and 313 are arranged at positions covered by the shielding layer 7. The reference numeral 7 in the drawing indicates the inner edge of the shielding layer 7.

The shielding layer 7 can have various modes such as only the inner surface of the outer glass plate 11, only the inner surface of the inner glass plate 12, or the inner surface of the outer glass plate 11 and the inner surface of the inner glass plate 12. Further, although it can be formed of ceramics and various materials, the following composition can be used, for example.
*1, Main component: Copper oxide, chromium oxide, iron oxide and manganese oxide *2, Main component: Bismuth borosilicate, Zinc borosilicate

The ceramic can be formed by a screen printing method. Alternatively, the ceramic can be produced by transferring a transfer film for firing onto a glass plate and firing it. When screen printing is adopted, for example, polyester screen: 355 mesh, coat thickness: 20 μm, tension: 20 Nm, squeegee hardness: 80 degrees, mounting angle: 75°, printing speed: 300 mm/s, drying oven A ceramic can be formed by drying at 150° C. for 10 minutes.

Further, the shielding layer 7 can be formed by laminating ceramics or by adhering a shielding film made of a dark resin.

<2. Windshield manufacturing method>
Next, a method for manufacturing the windshield will be described. First, a glass plate manufacturing line will be described.

Here, the molding die will be described in more detail with reference to FIGS. 3 and 4. FIG. 3 is a side view of the furnace through which the mold passes, and FIG. 4 is a plan view of the mold. As shown in FIG. 4, the molding die 800 includes a frame-shaped die body 810 that substantially matches the outer shapes of the glass plates 1 and 2. Since the mold body 810 is formed in a frame shape, it has an internal space 820 that penetrates in the vertical direction inside. Then, the peripheral portions of the flat glass plates 1 and 2 are placed on the upper surface of the mold body 810. Therefore, heat is applied to the glass plates 1 and 2 from a heater (not shown) arranged on the lower side through the internal space 820. As a result, both glass plates 1 and 2 are softened by heating and curved downward due to their own weight. In addition, a shield plate 840 for shielding heat may be arranged on the inner peripheral edge of the mold body 810, so that the heat received by the glass plates 1 and 2 can be adjusted. Further, the heater may be provided not only below the molding die 800 but also above it.

Then, after the above-described shielding layer 7 is laminated on the flat outer glass plate 1 and the inner glass plate 2, the outer glass plate 1 and the inner glass plate 2 are stacked and supported by the molding die 800. As shown in FIG. 3, it passes through a heating furnace 802. When heated to near the softening point temperature in the heating furnace 802, both glass plates 1 and 2 are curved downward due to their own weight inside the peripheral portion and are curved. Then, both glass plates 1 and 2 are carried into the slow cooling furnace 803 from the heating furnace 802, and a slow cooling process is performed. Then, both glass plates 1 and 2 are carried out from the slow cooling furnace 803 and are left to cool.

When the outer glass plate 11 and the inner glass plate 12 are formed in this manner, subsequently, the intermediate film 3 is sandwiched between the outer glass plate 11 and the inner glass plate 12. Specifically, first, the outer glass plate 1, the first adhesive layer 32, the heat generating layer 31, the second adhesive layer 33, and the inner glass plate 2 are laminated in this order. At this time, in the heat generating layer 31, the surface on which the first bus bar 312 and the like are formed faces the second adhesive layer 33 side. The upper and lower ends of the heat generating layer 31 are arranged inside the notches 21 and 22 of the inner glass plate 2. Further, the cutout portions of the first and second adhesive layers 32 and 33 are made to coincide with the cutout portions 21 and 22 of the inner glass plate 2. As a result, the outer glass plate 1 is exposed from the notches 21 and 22 of the inner glass plate 2. Then, the connecting members 41 and 42 are inserted between the heat generating layer 31 and the second adhesive layer 33 through the cutouts 21 and 22, respectively. At this time, a solder having a low melting point is applied as a fixing material 5 to each of the connecting members 41 and 42 so that the solder is arranged on each of the bus bars 312 and 313.

In this way, the laminated body in which the two glass plates 1 and 2, the intermediate film 3, and the connecting materials 41 and 42 are laminated is put in a rubber bag and pre-bonded at about 70 to 110° C. while vacuum suction. The pre-bonding method is not limited to this, and the following method can also be adopted. For example, the laminate is heated in an oven at 45 to 65°C. Next, this laminated body is pressed by a roll at 0.45 to 0.55 MPa. Subsequently, the laminate is heated again in an oven at 80 to 105° C. and then pressed again by a roll at 0.45 to 0.55 MPa. In this way, pre-bonding is completed.

Next, main adhesion is performed. The pre-bonded laminate is subjected to main bonding by an autoclave at, for example, 8 to 15 atm and 100 to 150°C. Specifically, for example, the main adhesion can be performed under the conditions of 14 atm and 135°C. Through the above pre-bonding and main bonding, both bonding layers 32 and 33 are bonded to the glass plates 1 and 2 with the heating layer 31 sandwiched therebetween. In addition, the solder of the connecting members 41 and 42 is melted, and the connecting members 41 and 42 are fixed to the bus bars 312 and 313. Thus, the laminated glass according to the present embodiment is manufactured.

<3. How to use the windshield>
The windshield configured as described above is attached to the vehicle body, and the connection terminals are fixed to the connection members 41 and 42. After that, when each connection terminal is energized, a current is applied to the heating wire 6 via the connection members 41, 42 and each bus bar 312, 313 to generate heat. Due to this heat generation, fogging of the windshield can be removed.

<4. Features>
As described above, according to this embodiment, the following effects can be obtained.

(1) First, the power consumption W by the heating wire 6 can be obtained by the following equation (1).
W=V ² R=(S/ρL)V ² (1)
However, V: voltage, R: resistance of heating wire, S: cross-sectional area of heating wire, L: length of heating wire, ρ: thermal conductivity

Here, the higher the voltage V, the more advantageous for the vehicle. For example, if the outputs of the motor and the generator are the same, the higher the drive voltage is, the smaller the current can be, and thus the power consumption can be reduced. Further, as the current becomes smaller, the diameter of the harness for supplying electric power can be made smaller, so that the weight of the vehicle is correspondingly reduced and the fuel consumption can be improved. Therefore, it is planned to change the power supply voltage of the vehicle to a voltage higher than the conventional 12V (for example, 48V). However, although increasing the voltage V has various advantages as described above, there is a problem in that the amount of heat generated increases. When the amount of heat generated is high, the glass is likely to crack, so it is preferable that the power consumption W be as small as possible. Therefore, it is necessary to increase the length L of the heating wire 6, and it is better to make the heating wire 6 in series, but since the heating wire 6 is a thin wire, there is a risk of disconnection. Therefore, considering this, it is preferable to arrange the heating wires 6 in parallel. However, arranging the heating wires in parallel generally shortens the length.

Therefore, in the present embodiment, in order to increase the length of the heating wire 6, the heating wire 6 is folded back between the bus bars 312 and 313 to increase the length. That is, each heating wire 6 is formed to have two folded portions 64 and 65, and each heating wire 6 is approximately three times as long as the length between both bus bars 312 and 313. .. Thereby, the power consumption W of each heating wire 6 can be reduced. As a result, the amount of heat generated can be reduced, and the glass plates 1 and 2 can be prevented from cracking. Specifically, for example, the heat generation amount per unit area of the heating wire 6 can be set to about 200 to 1000 W/m ² . With such a calorific value, it is possible to prevent the glass plates 1 and 2 from cracking and remove the fogging of the glass plates. The power supply voltage can be higher than the conventional 12V. Therefore, the power supply voltage is not limited to the above-mentioned 48V, and various power supply voltages of 24V to 100V can be applied. This point is the same throughout the present invention including the following embodiments.

Moreover, if the length of the heating wire 6 is lengthened, the number of the heating wire 6 arrange|positioned at the glass plates 1 and 2 can be reduced. That is, the number of the heating wires 6 arranged in parallel can be reduced while keeping the density of the heating wires 6 arranged on the glass plates 1 and 2 the same. This also makes it possible to reduce the amount of heat generated as a whole. In particular, since the heating wires 6 have the same density, it is difficult for the occupant to visually recognize the heating wires 6, thereby preventing the driver's visual field from being disturbed.

(2) By providing the folded-back portions 64 and 65, the heating wire 6 can be arranged at the same density as in the case of the power supply voltage of 12 V while satisfying the above-described line width and spacing of the heating wire 6. Therefore, it is possible to obtain the same heating distribution as in the case of the power source voltage of 12V. In addition, it is possible to prevent the heating wire 6 from being visually impaired by the driver or other occupants, and thereby hindering the driver's view.

(3) Since the bus bars 312 and 313 and the heating wire 6 are made of the same material, the coefficient of linear expansion of the bus bars 312 and 313 and the heating wire 6 is the same. This has the following advantages. When the bus bars 312 and 313 and the heating wire 6 are made of different materials, the linear expansion coefficients are different. Therefore, for example, when these members are separately manufactured and fixed, a harsh cycle such as a heat cycle test is performed. Due to a change in environment, there is a possibility that the heating wire is peeled off from the bus bar, or the two glass plates constituting the laminated glass are lifted from each other due to this, but as in the present embodiment, both bus bars are If the 312, 313 and the heating wire 6 are made of the same material, such a problem can be prevented.

(4) Since the bus bars 312 and 313 and the heating wire 6 are integrally formed, it is possible to prevent a contact failure between them and a heat generation failure. The heat generation failure will be described in detail below. Generally, in the case of heating a glass plate for antifogging, in order to prevent the occurrence of glass cracks, it is possible to control the current value so that the upper limit of the heating temperature is, for example, 70 to 80°C. Desired. On the other hand, if there is local heat generation due to the contact resistance as described above, it is necessary to control the current value with that portion as the upper limit of the heating temperature. As a result, there is a problem that the heating wire cannot be controlled so as to generate sufficient heat as a whole. However, according to the above configuration, since it is possible to prevent local heat generation, it is possible to control the heating wire so that it can sufficiently generate heat as a whole.

(5) The heat-generating layer 31 on which the bus bars 312 and 313 and the heating wire 6 are arranged is sandwiched between the adhesive layers 32 and 33, and this is arranged between the glass plates 1 and 2. Therefore, the heat generating layer 31 can be reliably fixed to both the glass plates 1 and 2. Further, by covering the two bus bars 312 and 313 and the heating wire 6 with the second adhesive layer 33, it is possible to prevent them from coming into contact with the glass plate. As a result, it is possible to prevent breakage of the glass plate.

(6) In the above embodiment, the two connecting members 41 and 42 are used to connect the bus bars 312 and 313 to external terminals. However, for example, a wide bus bar is prepared and It is also conceivable to cut unnecessary portions and then expose a part of the portions from the notches 21 and 22 to substitute for the connecting material. However, in this case, it is possible that local heat is generated at the corners of the cut bus bar. On the other hand, in the present embodiment, since the connecting members 41 and 42 that are separate bodies are fixed to the bus bars 312 and 313, such local heat generation can be prevented.

(7) In this embodiment, the bus bars 312 and 313 are arranged along the upper side 11 and the lower side 12 of the glass plates 1 and 2, respectively. Therefore, both bus bars 312 and 313 can be hidden by the shielding layer 7, and the appearance can be improved. In addition, in the present embodiment, only the bus bars 312 and 313 are arranged so as to be hidden by the shielding layer 7. However, for example, as shown in FIG. 5, the folded-back portions 64 and 65 of each heating wire 6 are also shield layers 7. You can hide in. As a result, the heating wire 6 can be further suppressed from being visually recognized from the outside or the inside of the vehicle.

The form of the heating wire 6 is not particularly limited, and in the present embodiment, the heating wire 6 is formed to have the two folded portions 64 and 65. However, three or more folded portions are provided, and the two bus bars 212 and 213 are provided. The length of the heating wire 6 extending between them can be further increased. Moreover, each part of the heating wire 6 does not necessarily need to extend in the vertical direction, and may be inclined to some extent. Further, the number and density of the heating wires 6 are not particularly limited, and the above FIGS. 1 and 5 are merely examples. This point is the same in the following embodiments and modifications.

<B. Second Embodiment>
Next, a second embodiment according to the present invention will be described with reference to FIG. FIG. 6 is a plan view of the windshield according to the second embodiment. The second embodiment is different from the first embodiment mainly in the arrangement of the bus bar and the heating wire. Therefore, only different parts will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted. To do.

As shown in FIG. 6, in the windshield according to the present embodiment, the first bus bar 312 is arranged on the left side of the lower side 12 of each of the glass plates 1 and 2, and the second bus bar 313 is arranged along the right side of the lower side 12. It is arranged. In accordance with this, the notches 21 and 22 of the inner glass plate 2 are both formed on the lower side 12. And the some heating wire 6 which connects these two bus bars 312 and 313 is arrange|positioned in parallel. More specifically, among the plurality of heating wires 6, the heating wires 6 arranged near the both side edges 13 and 14 are generally U-shaped (folded portions along the both side edges 13 and 14 and the upper edge 11). Are formed in one). On the other hand, the heating wire 6 arranged at a position near the center of the glass plates 1 and 2 in the left-right direction has a side portion 66 parallel to both side edges 13 and 14, and an upper portion 67 parallel to the upper edge. A concave portion 68 that is recessed downward is formed in the vicinity of the center of. As described above, since the heating wire 6 arranged on the center side has a short length if it is simply formed in a U shape, the concave portion 68 is formed so as to have a long length. Further, the heating wire arranged on the innermost side is provided with a convex portion 69 projecting further upward in the concave portion 68. As a result, the heating wire 6 arranged on the inner side is formed with the concave portion 68 and the convex portion 69, and a large number of folded portions are formed, thereby increasing the length. All heating wires 6 can be of approximately the same length. However, the lengths do not necessarily have to be the same, and the lengths may be slightly different.

As described above, according to this embodiment, the same effect as that of the first embodiment can be obtained. That is, also in the present embodiment, in order to increase the length of the heating wire 6, the heating wire 6 is folded back between the bus bars 312 and 313 to increase the length. Thereby, the power consumption W of each heating wire 6 can be reduced. As a result, the amount of heat generated can be reduced, and the glass plate can be prevented from cracking.

Further, since the two notches 21 and 22 through which the connecting material 4 is exposed are both formed on the lower side 12 of the inner glass plate 2, the connection of the connecting terminals becomes easy.

The shape of the heating wire is an example, and various shapes are possible. That is, the heating wire 6 on the outer side can be formed in a U shape so as to extend along the both side edges 13 and 14 and the upper side 11 of the glass plates 1 and 2, and the inner heating wire 6 and the outer heating wire 6 can be formed. Since it has the same length, it can be formed by further combining a plurality of concave portions 68 and convex portions 68.

In addition, in the present embodiment, both bus bars 312 and 313 are arranged along the lower side 12, but they may be arranged along the upper side 11, and in this case, the heating wire 6 is convex downward. It can be formed in a U shape.

<C. Third Embodiment>
Next, a third embodiment according to the present invention will be described with reference to FIG. FIG. 7 is a plan view of the laminated glass according to the third embodiment. The third embodiment is different from the first embodiment mainly in the arrangement of the bus bar and the heating wire. Therefore, only different parts will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted. To do.

As shown in FIG. 6, in the windshield according to the present embodiment, the first bus bar 312 is arranged on the left side of the lower side 12 of each of the glass plates 1 and 2, and the second bus bar 313 is arranged along the right side of the lower side 12. It is arranged. In addition to this, a strip-shaped first relay bus bar 71 is provided on the left side of the upper side 11 of the glass plates 1 and 2, and a strip-shaped second relay bus bar 72 is provided between the first and second bus bars 312 and 313 of the lower side 12. A strip-shaped third relay bus bar 73 is provided on the right side of the upper side 11 of the second bus 2. The first relay bus bar 71 is arranged at a position facing the first bus bar 312 and the second relay bus bar 72, and is formed to have substantially the same length from the left end portion of the first bus bar 312 to the vicinity of the center of the second relay bus bar 72. ing. The third relay bus bar 73 is disposed at a position facing the second relay bus bar 72 and the second bus bar 313, and has substantially the same length from the left end portion of the first bus bar 312 to the vicinity of the center of the second relay bus bar 72. Has been formed.

The plurality of heating wires 6 are composed of four parts. That is, each of the plurality of heating wires 6 has a first portion 601 connecting the first bus bar 312 and the first relay bus bar 71, a second portion 602 connecting the first relay bus bar 71 and the second relay bus bar 72, respectively. It is configured by a third portion 603 connecting the second relay bus bar 72 and the third relay bus bar 73, and a fourth portion 604 connecting the third relay bus bar 73 and the second bus bar 313. The plurality of first portions 601 extend upward in parallel from the first bus bar 312 and are connected to the left half of the first relay bus bar 71. The plurality of second portions 602 extend substantially in parallel downward from the right half of the first relay bus bar 71 and are connected to the left half of the second relay bus bar 72. In addition, the plurality of third portions 603 extend from the left half of the second relay bus bar 72 upward in a substantially parallel manner and are connected to the third relay bus bar 73. The plurality of fourth portions 604 extend downward from the right half of the third relay bus bar 73 in a substantially parallel manner and are connected to the second bus bar 213.

As described above, according to this embodiment, it is possible to obtain the same effect as that of the first embodiment. That is, three relay bus bars 71 to 73 are provided between the first bus bar 312 and the second bus bar 313, and the plurality of heating wires 6 arranged in parallel via the three relay bus bars 71 to 73 are connected to the first bus bar 312 and the second bus bar 313. Is configured to connect to. Therefore, the length of the heating wire 6 between the first bus bar 312 and the second bus bar 313 can be increased.

Although both bus bars 312 and 313 are arranged along the lower side 12 in the present embodiment, they may be arranged along the upper side 11. That is, as shown in FIG. 7, both bus bars 312 and 313 and the three relay bus bars 71 to 73 can be arranged at vertically opposite positions. The number of relay bus bars is not particularly limited, and two or four or more relay bus bars may be provided, and both ends of the heating wire are connected to the first bus bar 312 and the second bus bar 313 through all the relay bus bars. It should be.

<D. Fourth Embodiment>
Next, a fourth embodiment according to the present invention will be described with reference to FIG. FIG. 8 is a plan view of a laminated glass according to the fourth embodiment. The fourth embodiment is different from the first embodiment mainly in the arrangement of the bus bar and the heating wire. Therefore, only different parts will be described below, and the same components will be denoted by the same reference numerals and description thereof will be omitted. To do.

As shown in FIG. 8, in the windshield according to the present embodiment, the first bus bar 312 is arranged on the left side of the lower side 12 of each of the glass plates 1 and 2, and the second bus bar 313 is arranged along the right side of the lower side 12. It is arranged. In accordance with this, the notches 21 and 22 of the inner glass plate 2 are both formed on the lower side 12. And the some heating wire 6 which connects these two bus bars 312 and 313 is arrange|positioned in parallel. More specifically, among the plurality of heating wires 6, the heating wire 605 arranged near the both side edges 13 and 14 is formed in a substantially U-shape along the both side edges 13 and 14 and the upper edge 11. ing. Hereinafter, this heating wire will be referred to as a first heating wire 605.

On the other hand, the heating wire arranged near the center of the glass plates 1 and 2 in the left-right direction is also formed in a substantially U shape. Hereinafter, this heating wire will be referred to as a second heating wire 606. The second heating wire 606 has a shorter length than the first heating wire 605, but is formed of a material having a larger resistance than the first heating wire 605. For example, when the first heating wire 605 is made of copper, the second heating wire 606 can be made of nickel.

Other materials that can be used for the heating wires 605 and 606 include, for example, copper, tough pitch copper, oxygen-free copper, titanium, gold, chromium, molybdenum, tungsten, brass, nickel, beryllium copper, phosphor bronze, ITO and the like. The resistance value ((Ωm) 20° C.) increases in this order of description. Therefore, it is possible to form the first heating wire 605 with a material having a low resistance and the second heating wire 606 with a material having a high resistance. Among these materials, copper, tough pitch copper, oxygen-free copper, gold, brass, nickel, beryllium copper, and phosphor bronze are preferable because they have high workability such as etching. In particular, it is preferable to form the first heating wire 605 with copper and the second heating wire 606 with brass or nickel.

As described above, according to the present embodiment, the first heating wire 606 is formed along both sides and the upper side, and the length of the first heating wire 605 is longer than the distance between the bus bars 312 and 313. Therefore, the power consumption W of the first heating wire 6 can be reduced. On the other hand, although the length of the second heating wire 606 is not long, it is possible to reduce the power consumption because it is made of a material having high resistance. As a result, the amount of heat generation can be reduced.

As described above, the laminated glass using the heating wire made of two kinds of materials can also be configured as follows. As shown in FIG. 9, this laminated glass is a combination of the third embodiment and the fourth embodiment. Specifically, first, four cutouts are formed on the lower side 21 of the inner glass plate 2. These four notches will be referred to as first, second, third, and fourth notches 215 to 218 from left to right. Further, at positions corresponding to the first, second, third and fourth cutouts 215 to 218, along the lower side 12 of each of the glass plates 1 and 2, the first outer bus bar 315 and the first inner bus bar. 316, the second inner bus bar 317, and the second outer bus bar 318 are arranged in this order. Further, connecting members 41 to 44 exposed from the cutouts 215 to 218 are attached to the busbars 315 to 318, respectively.

Further, a relay bus bar 75 is arranged between the second inner bus bar 317 and the second outer bus bar 318 along the lower side 21 of the inner glass plate 2.

Then, the plurality of first heating wires 61 are arranged in parallel so as to connect the first outer bus bar 315 and the second outer bus bar 318. More specifically, the plurality of first heating wires 61 are formed in a substantially U shape so as to extend along the both side edges 13 and 14 and the upper edge 11. In addition, a plurality of second heating wires 62 are arranged in parallel so as to connect the first inner bus bar 316 and the second inner bus bar 317. However, the second heating wire 62 includes a first portion 621 that connects the first inner bus bar 316 and the relay bus bar 75, and a second portion 622 that connects the relay bus bar 75 and the second inner bus bar 317. .. The first portion 621 and the second portion 622 are both formed in a U shape and are surrounded by the first heating wire 61.

Therefore, the length of each part 621, 622 of the second heating wire 62 is shorter than that of the first heating wire 61. Therefore, similar to the fourth embodiment, the second heating wire 62 is made of a material having a higher resistance than the first heating wire 61. For example, when the first heating wire 605 is made of copper, the second heating wire 606 can be made of nickel. The selection of such a material is similar to that described above.

That is, by providing the relay bus bar 75 and increasing the length of the second heating wire 62, the amount of heat generation can be reduced. Further, in the example of FIG. 9, in addition to this, the second heating wire 62 is formed of a material having a high resistance, so that the heat generation amount can be further reduced.

<5. Modification>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. Further, the following modified examples can be appropriately combined.

<5.1>
In each of the above embodiments, the bus bars 312 and 313 are formed so as to be hidden by the shielding layer 7, but the present invention is not limited to this, and the bus bars may not be hidden by the shielding layer 7. Further, the shielding layer 7 does not necessarily have to be provided.

<5.2>
In the above-described embodiment, the intermediate film 3 is formed of the heat generating layer 31 and the pair of adhesive layers 32 and 33, which is a total of three layers, but is not limited to this. That is, the intermediate film 3 may include at least both the bus bars 312 and 313 and the heating wire 6. Therefore, for example, the adhesive layer may be only one layer, or the heat generating layer 31 may be sandwiched between the glass plates 1 and 2 with an adhesive or the like. The base material 311 may not be provided on the heat generating layer 31.

Specifically, it can be formed as follows. That is, as shown in FIG. 10, PVB having a thickness of several tens to several hundreds μm is used as the base material 311, and the bus bars 312 and 313 and the heating wire 6 are formed on the base material 311 by etching. Next, in the base material 311, PVB having a thickness of several hundred μm to several mm is laminated as an adhesive layer 32 on the surface on the side where the heating wire 6 is arranged. Thus, the intermediate film 3 is formed. As described above, when the intermediate film 3 is formed of only PVB, PVB is softer than PET, so that the followability is high and wrinkles can be prevented from occurring.

<5.3>
The heat generating layer 31 can have various shapes. For example, a sheet-shaped heat generating layer 31 in which both bus bars 312 and 313 and the heating wire 6 are formed on the base material 311 is prepared in advance, and this is appropriately cut and formed into an appropriate shape. It can be arranged between 1 and 2. Therefore, for example, if the edges of the glass plates 1 and 2 are curved, the edges of the base material 311 may be curved accordingly. Further, since the heat generating layer 31 does not have to be completely matched with the shape of the glass plates 1 and 2, and can be arranged only in a portion where the antifogging effect is desired, various shapes such as a shape smaller than the glass plates 1 and 2 can be obtained. It can be shaped. The glass plates 1 and 2 can also have various shapes other than a perfect rectangle.

In the above embodiment, both bus bars 312 and 313 and the heating wire 6 are arranged on the base material 311, but at least the heating wire 6 may be arranged. Therefore, for example, both bus bars 312 and 313 can be arranged between the adhesive layers 32 and 33.

<5.4>
Further, the adjacent heating wires 6 can be connected by at least one bypass wire. Thereby, for example, even if one heating wire 6 is broken, it is possible to energize from the adjacent heating wire 6. The position and number of bypass lines are not particularly limited. Further, the shape of the bypass line is not particularly limited, and the bypass line can be arranged in various shapes such as being arranged so as to extend obliquely and having a waveform. However, for example, in one heating wire 6 having folded portions 64 and 65 as shown in FIGS. 1 and 5, adjacent parts (for example, the first part 61 and the second part 62) are connected by a bus pass line. You cannot do it. Note that the bypass wire can be formed of the same metal material as the heating wire 314 and can be formed integrally with the heating wire 314.

<5.5>
The form of the connecting members 41 and 42 and the configuration of the cutout portions 21 and 22 of the inner glass plate 2 are not particularly limited. For example, as shown in FIG. 11, the inner glass plate 2 is formed with notches 21 and 22 having a small thickness of the connecting members 41 and 42, and the connecting members 41 and 42 extending from the bus bars 312 and 313 are cut into the cut members. It may be folded back at the notches 21 and 22 and attached to the surface of the inner glass plate 2. By doing so, it is possible to prevent the connecting members 41, 42 from protruding in the surface direction from the end portion of the laminated glass.

<5.6>
The shapes of the glass plates 1 and 2 are not particularly limited as long as the upper side 11, the lower side 12, the left side 13, and the right side 14 can be specified on the outer shape, and they are not necessarily rectangular. Further, each of the sides 11 to 14 may be a curve as well as a straight line. In addition, in each of the above embodiments, the bus bars 312 and 313 are arranged on the upper side 11 or the lower side 12, but they may be arranged on the left side 13 or the right side 14.

<5.7>
In each of the above-described embodiments, the heat generating layer is provided on the intermediate film, but instead of this, the bus bars 312 and 313 and the heating wire 6 are provided on the inner surface of the outer glass plate 1 or the inner surface of the inner glass plate 2 by screen printing or the like. Can be formed. In this case, the heat generating layer 31 can be formed of only the base material 311, or can be formed of at least one adhesive layer. The bus bars 312 and 313 and the heating wire 6 can be arranged as in the above-described embodiments.

<5.8>
In the above embodiment, an example in which the laminated glass of the present invention is applied to a windshield of an automobile has been shown, but the invention is not limited to this, and it may be applied to other vehicles such as a train and window glass of a building. it can.

1 Outer Glass Plate 2 Inner Glass Plate 3 Intermediate Film 31 Exothermic Layer 311 Base Material 312 First Bus Bar 313 Second Bus Bar 6 Heating Wire

Claims (12)

A rectangular first glass plate having a first side and a second side facing the first side;
A second glass plate that is arranged to face the first glass plate and has a substantially same shape as the first glass;
An intermediate film disposed between the first glass plate and the second glass plate,
Equipped with
The intermediate film is
A first bus bar extending along the end on the first side or the second side;
A second bus bar extending along the end on the first side or the second side;
A plurality of heating wires arranged in parallel so as to connect the first bus bar and the second bus bar,
Is equipped with
Wherein among the plurality of heating lines, at least one, between the first bus bar and the second bus bar, have at least one folded portion changing the direction of extension of the heating wire,
The plurality of heating wires includes at least one first heating wire and at least one second heating wire formed of a material having a higher resistance than the first heating wire,
A laminated glass in which the length of the first heating wire is longer than that of the second heating wire . The laminated glass according to claim 1, wherein each heating wire has a calorific value per unit area of 200 to 1000 W/m ² . The first bus bar is arranged along an end portion on the first side side,
The second bus bar is arranged along an end portion on the second side,
At least one of the plurality of heating wires has at least two folded-back portions that change the extending direction of the heating wire between the first bus bar and the second bus bar. Laminated glass according to. The first bus bar and the second bus bar are arranged along the same end of either the end on the first side or the end on the second side,
At least one of the plurality of heating wires has at least one folded-back portion that changes the extending direction of the heating wire between the first bus bar and the second bus bar. Laminated glass according to. At least one relay bus bar further arranged at a position different from that of the first bus bar and the second bus bar, and arranged along the end of the first side or the second side,
The laminated glass according to claim 1 or 2, wherein the plurality of heating wires are connected to the second bus bar from the first bus bar via at least one of the relay bus bars. Further comprising a shielding layer which is laminated on at least one of the first glass plate or the second glass plate and shields a visual field from the outside or inside of the vehicle,
It said first bus bar and second bus bar, the covered by the shielding layer, a laminated glass according to any one of claims 1 to 5. Further comprising a shielding layer which is laminated on at least one of the first glass plate or the second glass plate and shields a visual field from the outside or inside of the vehicle,
The laminated glass according to claim 3 or 4, wherein the first busbar, the second busbar, and at least one folded portion are covered with the shielding layer. The laminated glass according to any one of claims 1 to 7 , wherein the intermediate film includes a sheet-shaped base material that supports at least the plurality of heating wires. A heat generating layer is formed by the first bus bar, the second bus bar, the plurality of heating wires, and the base material,
The laminated glass according to claim 8 , wherein the intermediate film further includes a pair of adhesive layers that sandwich the heat generating layer. The laminated glass according to any one of claims 1 to 9 , wherein the first bus bar, the second bus bar, and the plurality of heating wires are integrally formed of the same material. The line width of the heating wire is 500μm or less, a laminated glass according to any one of claims 1 to 10. Wherein the plurality of voltage of 48V to the heating line is configured to be applied, laminated glass according to claims 1 11.