JP2017111974A - Heating plate, vehicle and building window - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of disconnection in a conductive thin wire of a heating conductor in a heating plate.SOLUTION: A heating plate 10 is a heating plate heating upon application of a voltage and includes a pair of glass 11, 12, a pair of bus bars 25 to which a voltage is applied, and a heating conductor 30 connecting between the pair of bus bars 25. The heating conductor 30 includes a plurality of conductive thin wires 31 linearly extending between the pair of bus bars 25 to connect therebetween. The average Wof widths W of bottoms of the conductive thin wires 31 is within a range represented by the following expression (a) with respect to a standard deviation σ of a distribution of the widths W. 0≤4σ/W≤0.3...Expression (a)SELECTED DRAWING: Figure 5

Description

  The present invention relates to a heat generating plate having a heat generating conductor, and a vehicle or building window having the heat generating plate.

  Conventionally, a heat generating plate that generates heat when a voltage is applied is known. As a typical application example, a heat generating plate configured to be transparent is used as a defroster device or a heater. A heat generating plate as a defroster device is used as a window glass of a vehicle front window (windshield) or a rear window. For example, in Patent Documents 1 and 2, a heat generating plate having transparency is used as a window glass. This heat generating plate has a heat generating conductor made of a tungsten wire or the like arranged over the whole. In this heat generating plate, when the heat generating conductor is energized, the heat generating conductor is heated by the resistance heating. By raising the temperature of the window glass made of a heat generating plate, fogging of the window glass can be removed, or snow and ice attached to the window glass can be melted to ensure transparency through the window glass.

JP 2013-173402 A JP-A-8-72674

  In the conventional heat generating plate, the conductive thin wire of the heat generating conductor extends linearly and connects the pair of bus bars. In such a heat generating plate, a portion where heat cannot be generated due to disconnection of the heat generating conductor is generated, and heat generation unevenness occurs. As a result of intensive studies by the present inventors, it has been found that the ease of disconnection of the conductive thin wire of the heat generating conductor depends on the width of the conductive thin wire. When conductive thin wires are arranged in a curved shape, disconnection is likely to occur at locations where the line width is small due to etching in the manufacturing process, particularly at locations where the curvature is large.

  In order to make disconnection difficult to occur, it is conceivable to increase the line width of the conductive thin line, but if the line width is increased, the conductive thin line is visually recognized in the appearance of the heat generating plate, and the visibility and design are deteriorated. . Therefore, it is necessary to make the distribution of the line widths of the conductive thin wires in a range in which disconnection hardly occurs and is not visually recognized. The present invention has been made in view of the above points, and an object of the present invention is to provide a heat generating plate in which a conductive thin wire of a heat generating conductor is hardly broken and the conductive thin wire is not visually recognized.

The heat generating plate according to the present invention is a heat generating plate that generates heat when a voltage is applied,
A pair of glasses;
A pair of bus bars to which a voltage is applied;
A heat generating conductor connecting between the pair of bus bars,
The heat generating conductor includes a plurality of conductive thin wires that extend and connect between the pair of bus bars in a linear shape,
The average W _ave of the width W of the conductive thin wire is in the range of the following formula (a) with respect to the standard deviation σ of the distribution of the width W.
0 ≦ 4σ / W _ave ≦ 0.3 Formula (a)

In the heat generating plate according to the present invention,
The conductive thin wire includes a large curvature portion having a relatively large curvature and a small curvature portion having a relatively small curvature,
The width W of the thin conductive wire may be thin at the large curvature portion and thick at the small curvature portion.

  The vehicle according to the present invention includes any of the heat generating plates according to the present invention described above.

  The building window according to the present invention includes any of the heat generating plates according to the present invention described above.

  According to the present invention, it is possible to prevent disconnection of the conductive thin wire of the heat generating conductor of the heat generating plate.

FIG. 1 is a diagram for explaining an embodiment according to the present invention, and is a perspective view schematically showing a vehicle provided with a heat generating plate. In particular, FIG. 1 schematically shows an automobile having a front window formed of a heat generating plate as an example of a vehicle. FIG. 2 is a view showing the heat generating plate from the normal direction of the plate surface. 3 is a cross-sectional view of the heat generating plate taken along line III-III in FIG. FIG. 4 is a plan view showing the sheet with the conductor from the normal direction of the sheet surface, and is a plan view showing an example of the sheet with the conductor. FIG. 5 is an enlarged plan view showing a part of the conductive thin wire. FIG. 6 is an enlarged view of a cross section of the sheet with a conductor. FIG. 7 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 8 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 9 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 10 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 11 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 12 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 13 is a diagram for explaining an example of a method for manufacturing a heat generating plate. FIG. 14 is a diagram for explaining an example of a method of manufacturing a heat generating plate. FIG. 15 is a diagram for explaining an example of a method for manufacturing a heat generating plate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  In the present specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in names. For example, “sheet with conductor” is a concept including a member that can be called a plate or a film. Therefore, “sheet with conductor” is “plate with conductor (substrate)” or “with conductor”. It cannot be distinguished from a member called “film” only by the difference in designation.

  In addition, in this specification, “sheet surface (plate surface, film surface)” means a target sheet when the target sheet-shaped (plate-shaped, film-shaped) member is viewed as a whole and globally. It refers to the surface that coincides with the planar direction of the plate-like member (plate-like member, film-like member). Moreover, the normal direction with respect to a sheet-like (film shape, plate-shaped) member is a normal direction to the sheet surface (film surface, plate surface) of the sheet-shaped (film shape, plate-shaped) member. Point to.

  Further, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, and the like are strict. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  1 to 15 are diagrams for explaining an embodiment according to the present invention. Of these, FIG. 1 is a diagram schematically showing an automobile equipped with a heat generating plate, FIG. 2 is a view of the heat generating plate viewed from the normal direction of the plate surface, and FIG. 3 is a heat generating of FIG. It is a cross-sectional view of a board.

  As shown in FIG. 1, an automobile 1 as an example of a vehicle has window glasses such as a front window, a rear window, and a side window. Here, an example in which the front window 5 is configured by the heat generating plate 10 will be described. The automobile 1 has a power source 7 such as a battery.

  As shown in FIGS. 2 and 3, the heating plate 10 in the present embodiment includes a pair of glasses 11, 12, a sheet 20 with a conductor disposed between the pair of glasses 11, 12, and each glass 11. , 12 and the conductor-attached sheet 20 are bonded to each other. In the example shown in FIGS. 1 and 2, the heat generating plate 10 and the glasses 11 and 12 are curved. However, in other drawings, the heat generating plate 10 and the glasses 11 and 12 are formed in a flat plate shape for easy understanding. It is shown in

  The conductor-attached sheet 20 includes a base film 21, a bus bar 25, and a heat generating conductor 30 that is provided on the surface of the base film 21 that faces the glass 11 and includes a conductive thin wire 31.

  Further, as well shown in FIG. 2, the heating plate 10 has a wiring portion 15 for energizing the heating conductor 30 of the sheet with conductor 20 via the bus bar 25. In the illustrated example, the heat generating conductor 30 is energized from the power source 7 such as a battery via the wiring portion 15 and the bus bar 25, and the conductive thin wires 31 of the heat generating conductor 30 are heated by resistance heating. The heat generated in the heat generating conductor 30 is transmitted to the glasses 11 and 12, and the glasses 11 and 12 are warmed. Thereby, the cloudiness by the dew condensation adhering to the glass 11 and 12 can be removed. Moreover, when snow and ice adhere to the glass 11 and 12, this snow and ice can be melted. Therefore, a passenger | crew's visual field is ensured favorable.

  Hereinafter, each component of the heat generating plate 10 will be described.

  First, the glasses 11 and 12 will be described. When the glasses 11 and 12 are used for a front window of an automobile as in the example shown in FIG. 1, it is preferable to use a glass having a high visible light transmittance so as not to disturb the sight of the passenger. Examples of such a material for the glasses 11 and 12 include soda lime glass and blue plate glass. The glasses 11 and 12 preferably have a transmittance of 90% or more in the visible light region. Here, the visible light transmittance of the glasses 11 and 12 was measured within a measurement wavelength range of 380 nm to 780 nm using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation, JIS K 0115 compliant product). Is specified as an average value of transmittance at each wavelength. The visible light transmittance may be lowered by coloring a part or the whole of the glass 11 or 12. In this case, it is possible to block direct sunlight and to make it difficult to visually recognize the inside of the vehicle from outside the vehicle.

  Moreover, it is preferable that the glasses 11 and 12 have a thickness of 1 mm or more and 5 mm or less. With such a thickness, the glasses 11 and 12 having excellent strength and optical characteristics can be obtained. The pair of glasses 11 and 12 may be the same with the same material, or may be different from each other in at least one of the material and the configuration.

  Next, the bonding layers 13 and 14 will be described. The 1st joining layer 13 is arrange | positioned between the 1st glass 11 and the sheet | seat 20 with a conductor, and joins the glass 11 and the sheet | seat 20 with a conductor mutually. The 2nd joining layer 14 is arrange | positioned between the 2nd glass 12 and the sheet | seat 20 with a conductor, and joins the glass 12 and the sheet | seat 20 with a conductor mutually.

  As the bonding layers 13 and 14, layers made of materials having various adhesiveness or tackiness can be used. The bonding layers 13 and 14 preferably have a high visible light transmittance. As a typical joining layer, the layer which consists of polyvinyl butyral (PVB) can be illustrated. The thickness of the bonding layers 13 and 14 is preferably 0.15 mm or more and 1 mm or less, respectively. The pair of bonding layers 13 and 14 may be configured identically with the same material, or may be different from each other in at least one of the material and the configuration.

  The heating plate 10 is not limited to the illustrated example, and may be provided with other functional layers expected to exhibit a specific function. In addition, one functional layer may exhibit two or more functions. For example, glass 11 and 12 of the heating plate 10, bonding layers 13 and 14, and a base film of a sheet 20 with a conductor to be described later Some function may be given to at least one of 21. Examples of functions that can be imparted to the heat generating plate 10 include an antireflection (AR) function, a hard coat (HC) function having scratch resistance, an infrared shielding (reflection) function, an ultraviolet shielding (reflection) function, and an antifouling function. A function etc. can be illustrated.

  Next, the sheet with conductor 20 will be described. The conductor-attached sheet 20 includes a base film 21, a bus bar 25, and a heat generating conductor 30 that is provided on the surface of the base film 21 that faces the glass 11 and includes a conductive thin wire 31. The conductor-equipped sheet 20 has substantially the same planar dimensions as the glasses 11 and 12 and may be disposed over the entire heat generating plate 10, or the heat generating plate 10 such as the front portion of the driver's seat in the example of FIG. 1. It may be arranged only in a part of.

  The substrate film 21 functions as a substrate that supports the heat generating conductor 30. The base film 21 is an electrically insulating substrate that is transparent in general terms that transmits wavelengths in the visible light wavelength band (380 nm to 780 nm). The base film 21 may be made of any material as long as it transmits visible light and can appropriately support the heat generating conductor 30, for example, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, cyclic Examples include polyolefin. In addition, the base film 21 preferably has a thickness of 0.03 mm or more and 0.20 mm or less in consideration of light transmittance, appropriate supportability of the heat generating conductor 30, and the like.

  Next, the heat generating conductor 30 will be described with reference to FIG. FIG. 4 is a plan view showing the heat generating conductor 30 from the normal direction of the sheet surface. FIG. 4 is a diagram illustrating an example of the arrangement of the heat generating conductors 30.

  As shown in FIG. 4, the heat generating conductor 30 has a plurality of linear conductive thin wires 31 connecting the pair of bus bars 25. The conductive thin wire 31 is energized from the power source 7 such as a battery through the wiring portion 15 and the bus bar 25 and generates heat by resistance heating. And when this heat | fever is transmitted to the glass 11 and 12 via the joining layers 13 and 14, the glass 11 and 12 is warmed.

  In the example shown in FIG. 4, the plurality of thin conductive wires 31 each extend from one bus bar 25 to the other bus bar 25. The plurality of conductive thin wires 31 are arranged apart from each other. In particular, the plurality of conductive thin wires 31 are arranged in a direction orthogonal to the extending direction of the conductive thin wires 31. A gap 35 is formed between two adjacent conductive thin wires 31.

  Examples of the material for forming the heat generating conductor 30 include metals such as gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, and nickel- One or more alloys of two or more metals selected from these exemplified metals such as chromium alloy and brass can be exemplified.

  The heating conductor 30 can be formed using an opaque metal material as described above. On the other hand, the conductive thin wires 31 of the heat generating conductor 30 are formed with a high non-coverage ratio of about 70% to 90%. For this reason, the area | region in which the electroconductive thin wire 31 and the connection electroconductive thin wire 32 of the conductor 30 for a heat | fever are formed is grasped | ascertained transparently as a whole, and it does not impair visibility.

  In the example shown in FIG. 3, the conductive thin wire 31 has a substantially trapezoidal cross section as a whole. More precisely, the side surface of the conductive thin wire 31 has a concave curved surface for etching in the manufacturing process described later. Further, the width W of the bottom of the conductive thin wire 31, that is, the length along the plate surface of the heat generating plate 10 is 11 μm or more and 20 μm or less, and the height (thickness) H, that is, the plate surface of the heat generating plate 10. The height (thickness) along the normal direction is preferably 1 μm or more and 60 μm or less. According to the conductive thin wire 31 having such dimensions, since the conductive thin wire 31 is sufficiently thinned, the heat generating conductor 30 can be effectively invisible.

  As shown in FIG. 3, the conductive thin wire 31 is a first dark color layer that covers the conductive metal layer 36 and the surface of the conductive metal layer 36 that faces the base film 21. 37. A second dark color layer 38 that covers the surface opposite to the glass 11 and both side surfaces of the surface of the conductive metal layer 36 is included.

  The conductive metal layer 36 made of a metal material having excellent conductivity exhibits a relatively high reflectance. When the light is reflected by the conductive metal layer 36 forming the conductive thin wire 31 of the heat generating conductor 30, the reflected light is visually recognized, which may obstruct the occupant's field of view. Further, when the conductive metal layer 36 is visually recognized from the outside, the designability may be deteriorated. Therefore, the first and second dark color layers 37 and 38 are disposed on at least a part of the surface of the conductive metal layer 36. The first and second dark color layers 37 and 38 may be layers having a visible light reflectance lower than that of the conductive metal layer 36, and are dark color layers such as black. The dark color layers 37 and 38 make it difficult for the conductive metal layer 36 to be visually recognized, so that the occupant's field of view can be favorably secured. Moreover, the fall of the designability when seen from the outside can be prevented.

  Note that, as described above, the conductive thin wires 31 of the heat generating conductor 30 are formed on the base film 21 with a high non-coverage ratio from the viewpoint of ensuring transparency or visibility. For this reason, as shown in FIG. 3, the bonding layer 13 and the base film 21 of the conductor-attached sheet 20 pass through an uncovered portion of the conductive thin wire 31, that is, a region between the adjacent conductive thin wires 31. Touching. For this reason, the heat-generating conductor 30 is embedded in the bonding layer 13.

Incidentally, FIG. 5 shows an enlarged view of a part of the conductive thin wire 31 viewed from the normal direction of the sheet surface. As a result of extensive studies by the present inventors, as shown in FIG. 5, the conductive thin wires 31 of the heat generating conductor 30 actually produced have a distribution in the line width W along the longitudinal direction thereof. It becomes like this. Such a tendency remarkably occurred in the heat generating conductor 30 of the sheet with conductor 20 manufactured by the manufacturing method described later with reference to FIGS. And when the present inventors investigated the relationship between the fluctuation | variation of the line width W and the disconnection of the electroconductive thin wire 31, the fluctuation | variation of the line width W can have a strong influence on the ease of disconnection of the electroconductive thin wire 31. FIG. It was confirmed. As a result of confirmation by the present inventors, when the average width W of the conductive thin wires 31 is W _ave and the standard deviation is σ, heat is generated when the width W is distributed so as to satisfy the following formula (a). The width of the conductive thin wire 31 could be set in a range in which the conductive thin wire 31 of the electrical conductor 30 is hardly broken and the conductive thin wire 31 is not visually recognized.
0 ≦ 4σ / W _ave ≦ 0.3 Formula (a)

  In addition, FIG. 6 is an enlarged view of the conductive thin wire 31 on the sheet with a conductor 20 as seen from the cross section. In FIG. 6, the conductive metal layer and the dark color layer are omitted. The thin conductive wire 31 shown in FIG. 6 shows a cross section of the thin conductive wire 31 produced by the manufacturing method described later. In the example shown in FIG. 6, the width W of the conductive fine wire 31 changes at each position along the normal direction of the sheet 20 with the conductor. In the example shown in FIG. 6, the width W of the conductive fine wire 31 changes at each position along the normal direction of the sheet 20 with the conductor. With respect to the conductive thin wire 31 whose width W varies along the normal direction of the sheet 20 with the conductor, the width W of the conductive thin wire 31 indicates the maximum width in each cross section that easily affects disconnection or visualization. I will do it. That is, in the example blinded in FIG. 6, the width W of the conductive thin wire 31 refers to the width at the bottom closest to the base film 21.

  Further, as shown in FIG. 5, the conductive thin wire 31 includes a curved portion, and not only the width of the curved portion but also the curvature is not constant. In particular, in the illustrated example, the conductive thin wire 31 is formed only by a curved portion. When the conductive thin wire 31 includes a curved portion, generation of strong streak-like light in a specific direction, that is, light glare, due to diffraction by the conductive thin wire 31 can be effectively made inconspicuous.

  As shown in FIG. 5, the curvature of the curved portion of the conductive thin wire 31 is not constant. In particular, the conductive thin wire 31 has a relatively small curvature (a portion having a relatively small curvature (a small curvature portion; see the reference numeral “A” in FIG. 5)) and a “curvature that is relatively different from each other. Portion (first large curvature portion; see reference numeral “B” in FIG. 5)) ”. The width W of the conductive main thin wire 31 is thick at the small curvature portion A where the curvature is relatively small, and is thin at the large curvature portion B where the curvature is relatively large. As a result of extensive research conducted by the present inventors, the width W of the conductive main fine wire 31 is thick at the small curvature portion A and thin at the large curvature portion B, so that the small curvature portion A is visually recognized as a dot. As a result, the heat generating conductor 30 can be effectively invisible.

  Next, an example of a method for manufacturing the heat generating plate 10 will be described with reference to FIGS. FIGS. 7 to 10 and FIGS. 13 to 15 are cross-sectional views sequentially showing an example of a method for manufacturing the heat generating plate 10. FIG. 11 and FIG. 12 are diagrams for explaining the dispersion of an etching solution for etching described later.

  First, as shown in FIG. 7, a dark color film 37 a for forming the first dark color layer 37 on the base film 21 is provided. The base film 21 may be made of any material as long as it can appropriately hold the heat generating conductor 30. Examples thereof include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, and cyclic polyolefin. it can. In consideration of the retention property of the heat generating conductor 30 and the like, the thickness of the base film 21 is preferably 30 μm or more and 150 μm or less. The dark color film 37a can be provided by, for example, a plating method including electroplating and electroless plating, a sputtering method, a CVD method, a PVD method, an ion plating method, or a combination of two or more thereof. Various known materials can be used as the material of the dark color film 37a. For example, copper nitride, copper oxide, nickel nitride and the like can be exemplified.

  Next, as shown in FIG. 8, a metal film 36a for forming the conductive metal layer 36 is provided on the dark color film 37a. As already described as the material forming the conductive metal layer 36, the metal film 36a is made of gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, and alloys thereof. It can be formed using one or more. The metal film 36a can be formed by a known method. For example, a method of attaching a metal foil such as a copper foil, a plating method including electroplating and electroless plating, a sputtering method, a CVD method, a PVD method, an ion plating method, or a method in which two or more of these are combined is adopted. can do.

  Next, as shown in FIG. 9, a resist pattern 39 is provided on the metal film 36 a to create an etching target material (in the illustrated example, a sheet-like member to be etched) 40. The resist pattern 39 has a shape corresponding to the heat generating conductor 30 to be formed. In the method described here, the resist pattern 39 is provided only on the portion finally forming the heat generating conductor 30. The resist pattern 39 can be formed by patterning using a known photolithography technique.

  Next, as shown in FIG. 10, the metal film 36a and the dark color film 37a of the material to be etched 40 are etched using the resist pattern 39 as a mask. By this etching, the metal film 36 a and the dark color film 37 a are patterned into a pattern substantially the same as the resist pattern 39. As a result, a conductive metal layer 36 that forms part of the conductive thin wire 31 is formed from the patterned metal film 36a. In addition, a first dark color layer 37 that forms part of the conductive thin wires 31 and the connected conductive thin wires 32 is formed from the patterned dark color film 37a.

  Here, an etching method will be described with reference to FIGS. First, as shown in FIG. 11, the material to be etched (in the illustrated example, a sheet-like member to be etched) 40 is moved in the direction of the arrow. At this time, the extending direction of the resist pattern 39, that is, the extending direction of the conductive metal layer 36 generated after etching, and the traveling direction of the material to be etched 40 are matched. Then, an etching solution is sprayed from a spray 50 provided above the material to be etched 40 to the material 40 to be etched. At this time, the etching solution is sprayed while the spray 50 is swung perpendicularly to the traveling direction of the material to be etched 40. According to this aspect, the etching solution can be uniformly distributed in a direction perpendicular to the extending direction of the resist pattern 39. Further, by adjusting the spraying amount of the etchant from the spray 50 and the traveling speed of the material to be etched 40, the degree of etching progress with respect to the entire material to be etched 40 can be adjusted.

  When the etching solution is sprayed as described above, the etching solution is relatively diffused at a portion where the curvature of the resist pattern 39 is small as in the region A ′ of FIG. Therefore, the width of the conductive metal layer 36 that finally forms the conductive thin wire 31 is increased. That is, in the small curvature portion A shown in FIG. 5, the line width W of the conductive thin wire 31 is relatively thick. On the other hand, as the region B 'has a larger curvature of the resist pattern 39, the etching solution is more concentrated, so that the etching proceeds relatively quickly. Therefore, the width of the conductive metal layer 36 that finally forms the conductive thin wire 31 is reduced. That is, in the large curvature portion B shown in FIG. 5, the line width W of the conductive thin wire 31 is relatively thin. That is, in accordance with the etching method shown in FIG. 11, the curvature of the resist pattern 39, that is, the conductivity to be formed, is adjusted by adjusting the spraying amount of the etching liquid from the spray 50 and the traveling speed of the material 40 to be etched. The width W of the conductive thin wire 31 can be controlled according to the curvature of the conductive thin wire 31.

  Thus, the width of the conductive metal layer 36 that finally forms the conductive thin wire 31 can be easily adjusted by the amount of the etching solution sprayed on the resist pattern 39 and the traveling speed of the material 40 to be etched. Etching is adjusted so that it does not proceed excessively at a portion where the curvature of the resist pattern 39 is large. As described above, the material to be etched 40 is etched, and the conductive metal layer 36 and the first dark color layer 37 are formed. Thereafter, as shown in FIG. 13, the resist pattern 39 is removed.

  Next, as shown in FIG. 14, the second dark color layer 38 is formed on the surface 31a and the side surfaces 31c, 31d opposite to the surface 31b on which the first dark color layer 37 of the conductive metal layer 36 is provided. For example, the second dark color layer 38 is subjected to a darkening process (blackening process) on a part of the material forming the conductive metal layer 36, and the metal oxide or metal sulfide is formed from a part of the conductive metal layer 36. A second dark color layer 38 made of a material can be formed. Further, a second dark color layer 38 may be provided on the surface of the conductive metal layer 36, such as a coating film of a dark color material or a plating layer of nickel or chromium. Alternatively, the surface of the conductive metal layer 36 may be roughened to provide the second dark color layer 38. Through the above steps, the conductor-attached sheet 20 is produced.

  Finally, as shown in FIG. 15, the bonding layer 13 and the glass 11 are laminated from the heat-generating conductor 30 side of the conductor-attached sheet 20 and, for example, by heating and pressing, Join. Similarly, the joining layer 14 and the glass 12 are laminated | stacked from the base film 21 side, and the sheet | seat 20 with a conductor and the glass 12 are joined. Thereby, the heat generating plate 10 shown in FIG. 3 is produced.

As described above, the heat generating plate 10 in the present embodiment is a heat generating plate that generates heat when a voltage is applied, and includes a pair of glasses 11 and 12, a pair of bus bars 25 to which a voltage is applied, and a pair of A heat generating conductor 30 connecting between the bus bars 25. The heat generating conductor 30 includes a plurality of conductive thin wires 31 extending linearly between the pair of bus bars 25, and the conductive thin wires The average W _ave of the width W at the bottom of 31 is within the range of the following equation (a) with respect to the standard deviation σ of the distribution of the width W.
0 ≦ 4σ / W _ave ≦ 0.3 Formula (a)
According to such a heat generating plate 10, since the difference in the width W of the bottom of the conductive thin wire 31 is small as a whole, the conductive thin wire 31 of the heat generating conductor 30 is not easily broken, and the conductive thin wire 31 is visible. The width of the conductive thin wire 31 can be set within a range where the operation is not performed. For this reason, heat generation unevenness hardly occurs in the heat generating plate 10 and a good field of view through the heat generating plate 10 is obtained.

  Moreover, in the heat generating plate 10 in the present embodiment, the conductive thin wire 31 includes a large curvature portion B having a relatively large curvature of the pattern in plan view and a small curvature portion A having a relatively small curvature of the pattern in plan view. Including. The width W of the thin conductive wire 31 is narrow at the large curvature portion B and thick at the small curvature portion A. According to this embodiment, the heat generating conductor 30 can be effectively invisible.

  The heat generating plate 10 may be used for a front window, a side window, or a sunroof of the automobile 1. Moreover, you may use for the windows or transparent doors of vehicles other than a motor vehicle, such as a railway vehicle, an aircraft, a ship, and a spacecraft.

  Furthermore, the heat generating plate 10 can be used as a building window such as a building or a store, a window of a house, a transparent door, or the like, in addition to a vehicle, in particular, a section that separates the room from the outside.

  Various changes can be made to the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Car 5 Front window 7 Power supply 10 Heat generating plate 11 Glass 12 Glass 13 Bonding layer 14 Bonding layer 15 Wiring part 20 Sheet with conductor 21 Base film 25 Bus bar 30 Heating conductor 31 Conductive thin wire 35 Gap 36 Conductive metal layer 37 first dark color layer 38 second dark color layer 39 resist pattern

Claims (4)

A heating plate that generates heat when a voltage is applied,
A pair of glasses;
A pair of bus bars to which a voltage is applied;
A heat generating conductor connecting between the pair of bus bars,
The heat generating conductor includes a plurality of conductive thin wires that extend and connect between the pair of bus bars in a linear shape,
The heat generating plate, wherein an average W _ave of the width W of the conductive thin wires is within a range of the following formula (a) with respect to a standard deviation σ of the distribution of the width W.
0 ≦ 4σ / W _ave ≦ 0.3 Formula (a) The conductive thin wire includes a large curvature portion having a relatively large curvature and a small curvature portion having a relatively small curvature,
2. The heat generating plate according to claim 1, wherein a width W of the conductive thin wire is thin in the large curvature portion and thick in the small curvature portion.   A vehicle comprising the heat generating plate according to claim 1.   A building window comprising the heating plate according to claim 1.

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