JP6569346B2 - Transparent heating plate and window with transparent heating plate - Google Patents

Description

  The present invention relates to a transparent heating plate and a window provided with the transparent heating plate.

  Conventionally, for example, a heat generating plate described in Patent Document 1 is known as a transparent heat generating plate used for windows of various buildings such as houses. According to such an appliance, it is possible to exert functions such as anti-fogging, snow melting or defrosting of windows by energizing a heating element such as a heating wire in the heating plate and heating the heating plate by resistance heating. .

Japanese Utility Model Publication No. 6-16032

  In the prior art, the transparent heat generating plate is usually fixed to the frame member for the purpose of preventing damage and ensuring airtightness. In this case, the heat generated by the heating element of the transparent heating plate is transmitted to the frame member by heat conduction. Therefore, the region near the peripheral edge of the transparent heat generating plate that is in contact with the frame member has a lower temperature than the central portion of the transparent heat generating plate as a result of the heat deprived by the frame member. That is, the temperature distribution in the transparent heat generating plate is not uniform. As a result, the transparent heat generating plate of the prior art cannot sufficiently exhibit the antifogging, snow melting or defrosting functions at the peripheral edge of the transparent heat generating plate which is at a lower temperature than the central portion.

  The present invention has been made in consideration of such points, and an object thereof is to make the temperature distribution in the transparent heating plate uniform.

The transparent heating plate according to the present invention is
A transparent substrate, and a heating conductor that is laminated with the transparent substrate and generates heat when a voltage is applied thereto,
The amount of heat generated per unit area in at least a part of the peripheral edge of the transparent heat generating plate is higher than the amount of heat generated per unit area in the central portion of the transparent heat generating plate.

In the transparent heating plate according to the present invention,
The transparent substrate has a first transparent substrate and a second transparent substrate that are stacked on each other,
The heat generating conductor may be disposed between the first transparent substrate and the second transparent substrate.

In the transparent heating plate according to the present invention,
The heat generating conductor may have a plurality of conductive thin wires.

In the transparent heating plate according to the present invention,
At least some of the plurality of conductive thin wires may have a calorific value per unit length changing in one conductive thin wire.

In the transparent heating plate according to the present invention,
The width of at least some of the plurality of conductive thin wires may change along the extending direction of the conductive thin wires.

In the transparent heating plate according to the present invention,
The heat generation amount per unit length of some of the plurality of conductive thin wires may be different from the heat generation amount per unit length of any of the other conductive thin wires.

In the transparent heating plate according to the present invention,
The width of some of the plurality of conductive thin wires may be different from the width of any of the other conductive thin wires.

In the transparent heating plate according to the present invention,
The arrangement pitch of at least some of the plurality of conductive thin wires may change along the arrangement direction.

The window according to the invention
The transparent heating plate described above and a frame member that contacts at least a part of the periphery of the transparent heating plate.

  According to the present invention, the temperature distribution in the transparent heat generating plate can be made uniform.

FIG. 1 is a diagram for explaining an embodiment according to the present invention, and schematically showing a building window provided with a transparent heating plate. FIG. 2 is a perspective view showing a window having a transparent heating plate and a frame member. FIG. 3 is a plan view showing the transparent heat generating plate from the normal direction of the plate surface. FIG. 4 is a cross-sectional view of the transparent heat generating plate corresponding to the line IV-IV in FIG. FIG. 5 is a plan view showing a sheet with a conductor of the transparent heating plate of FIG. FIG. 6 is an enlarged view showing a part of the heat generating conductor of the conductor-attached sheet of FIG. FIG. 7 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 8 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 9 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 10 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 11 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 12 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 13 is a diagram for explaining an example of a method for manufacturing a transparent heating plate. FIG. 14 is a view showing a modification of the heat generating conductor of the transparent heat generating plate of FIG. 3, and is an enlarged view showing a part of the heat generating conductor in an enlarged manner. FIG. 15 is a plan view showing another modification of the pattern of the heat generating conductor of the transparent heat generating plate. FIG. 16 is a plan view showing still another modified example of the pattern of the heat generating conductor of the transparent heat generating plate. FIG. 17 is a plan view showing still another modified example of the pattern of the heat generating conductor of the transparent 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 this specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in designation. For example, “sheet” is a concept that includes a member that can be called a plate or a film. Therefore, “sheet with conductor” is “plate with conductor (substrate)” or “film with conductor”. It cannot be distinguished only by the difference between the called member and the name.

  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 member, film-like member).

  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, etc. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  1-17 is a figure for demonstrating one Embodiment by this invention. Of these, FIG. 1 is a diagram schematically showing a window of a building having a transparent heating plate, FIG. 2 is a perspective view showing a window having a transparent heating plate and a frame member, and FIG. 3 is transparent. FIG. 4 is a view of the heat generating plate as viewed from the normal direction to the plate surface, FIG. 4 is a cross-sectional view corresponding to line IV-IV of the transparent heat generating plate of FIG. 3, and FIG. It is a top view which shows a sheet | seat with a body.

  Below, the window 1 is a window for buildings (refer FIG. 1), and the example in which this window 1 is comprised with the transparent heating plate 10 is demonstrated.

  As shown in FIG. 2, the window 1 includes a transparent heating plate 10 and a frame member 5 that contacts at least a part of the periphery of the transparent heating plate 10. In particular, the transparent heat generating plate 10 is viewed from the normal direction of the plate surface of the transparent heat generating plate 10 (hereinafter, also referred to as a plan view), and two side edges 10a and 10c that are parallel to each other and orthogonal to the side edges 10a and 10c. The frame member 5 is formed in a rectangular shape having two side edges 10b and 10d that are parallel to each other (see FIG. 3). The frame member 5 surrounds the periphery of the transparent heat generating plate 10 and It is formed in a frame shape so as to be in contact with the surroundings. The frame member 5 is in contact with at least a part of the periphery of the transparent heating plate 10 and holds the transparent heating plate 10. Note that “the frame member 5 and the transparent heat generating plate 10 are in contact with” the frame member 5 and the transparent heat generating plate 10 not only directly contact each other, but the frame member 5 and the transparent heat generating plate 10 are bonded to each other. The case where it contacts via other members, such as a buffer material and a spacer, is also included.

  As shown in the cross-sectional view of FIG. 4, the transparent heat generating plate 10 in the present embodiment is provided between the first transparent substrate 11 and the second transparent substrate 12 and the transparent substrates 11, 12 that are stacked on each other. It has the sheet | seat 20 with a conductor arrange | positioned, and a pair of joining layers 13 and 14 which join each transparent substrate 11 and 12 and the sheet | seat 20 with a conductor.

  The sheet 20 with a conductor is a base film 21, a heating conductor 30 provided on the surface of the base film 21 facing the first transparent substrate 11, and a pair for energizing the heating conductor 30. Bus bar 25. In the illustrated example, the heat generating conductor 30 is formed as an assembly of a plurality of conductive thin wires 31 connecting the pair of bus bars 25.

  Further, as shown in FIG. 3, the transparent heat generating plate 10 has a wiring portion 15 for energizing the heat generating conductor 30. In the illustrated example, the power source 7 energizes the heat generating conductor 30 from the wiring portion 15 through the bus bar 25 of the sheet 20 with the conductor, and the heat generating conductor 30 generates heat by resistance heating. The heat generated in the heat generating conductor 30 is transmitted to the transparent substrates 11 and 12, and the transparent substrates 11 and 12 are warmed. Thereby, the cloudiness by the dew condensation adhering to the window 1 can be removed. Moreover, when snow and ice adhere to the window 1, this snow and ice can be melted. Therefore, the lighting performance of the window 1 and the visibility through the window 1 are ensured satisfactorily. In FIG. 3, the heat generating conductor 30 is not shown.

  The “transparent” of the transparent heat generating plate 10 means that the transparent heat generating plate 10 has transparency enough to allow the other side to be seen through from the transparent heat generating plate. For example, it means having a visible light transmittance of 20% or more, more preferably 70% or more. Visible light transmittance is the transmittance at each wavelength when 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). Specified as the average value of. In addition, “transparent” in the present invention may be cloudy transparent such as high-haze frosted glass, in addition to low haze (cloudiness) and no cloudiness. Furthermore, “transparent” as used in the present invention may be colored transparent in addition to colorless and transparent.

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

  When the transparent substrates 11 and 12 are used for a building window as in the example shown in FIG. 1, the transparent substrates 11 and 12 have a high visible light transmittance from the viewpoint of ensuring visibility or lighting through the transparent heating plate 10. Is preferably used. Examples of the material of the transparent substrates 11 and 12 include soda lime glass (soda glass and blue plate glass), borosilicate glass, quartz glass, potash glass, and the like. The visible light transmittance of the transparent substrates 11 and 12 is preferably 90% or more. However, the visible light transmittance of a part of the transparent substrates 11 and 12 may be lowered by coloring or the like. In this case, it is possible to moderately reduce direct sunlight and to make it difficult to visually recognize the indoor from the outside.

  Moreover, it is preferable that the transparent substrates 11 and 12 have a thickness of 1 mm or more and 5 mm or less. With such a thickness, it is possible to obtain the transparent substrates 11 and 12 having excellent strength and optical characteristics. The pair of transparent substrates 11 and 12 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.

  Next, the bonding layers 13 and 14 will be described. The joining layer 13 is arrange | positioned between the 1st transparent substrate 11 and the sheet | seat 20 with a conductor, and joins the 1st transparent substrate 11 and the sheet | seat 20 with a conductor mutually. The bonding layer 14 is disposed between the second transparent substrate 12 and the sheet with conductor 20, and bonds the second transparent substrate 12 and the sheet with conductor 20 to each other.

  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 transparent heat generating 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, the transparent substrates 11 and 12, the bonding layers 13 and 14 of the transparent heating plate 10, and a base of the sheet 20 with a conductor to be described later. A certain function may be given to at least one of the material films 21. Examples of functions that can be imparted to the transparent heating plate 10 include antireflection (AR) function, hard coat (HC) function having scratch resistance, infrared shielding (reflection or absorption) function, and ultraviolet shielding (reflection or absorption). ) Functions, antifouling functions, antistatic functions, coloring functions, and the like.

  Next, with reference to FIG.5 and FIG.6, the sheet | seat 20 with a conductor is demonstrated. The conductor-attached sheet 20 includes a base film 21, a heat generating conductor 30 provided on the surface of the base film 21 facing the first transparent substrate 11 and including a plurality of conductive thin wires 31, and a heat generating conductive material. And a pair of bus bars 25 for energizing the body 30. The sheet with a conductor 20 shown in FIG. 5 has two side edges 20a and 20c that are parallel to each other, and two side edges 20b and 20d that are orthogonal to the side edges 20a and 20c and are parallel to each other. Thus, it is formed in a rectangular shape. Each bus bar 25 is arranged along the side edges 20a and 20c of the sheet with conductor 20 in parallel with the side edges 20a and 20c. In FIG. 5 (the same applies to FIGS. 15 to 17), the side edges 20a, 20b, 20c, and 20d of the conductor-attached sheet 20 are the side edges 10a, 10b, 10c, and 10d of the transparent heating plate, respectively. They are in a positional relationship that faces each other (when both are viewed from the normal direction of the plate surface of the transparent heat generating plate 10, if 10d is on the right side, 20d is also on the right side).

  The substrate film 21 functions as a substrate that supports the heat generating conductor 30. The base film 21 is an electrically insulating film that is transparent in general terms and transmits a wavelength (380 nm to 780 nm) in the visible light wavelength band. 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 FIGS. FIG. 5 is a plan view of the heating element-equipped sheet 20 having the heating conductor 30 as viewed from the normal direction of the sheet surface. FIG. 6 is an enlarged view showing a part of the heat generating conductor 30 of FIG. In particular, FIG. 6 shows an enlarged region surrounded by a circle indicated by a one-dot chain line in FIG.

  The heat generating conductor 30 has a plurality of thin conductive wires 31 disposed between the pair of bus bars 25. A voltage is applied to the conductive thin wire 31 from the power supply 7 through the wiring portion 15 and the bus bar 25, and heat is generated by resistance heating by energization. Then, the heat is transferred to the transparent substrates 11 and 12 through the bonding layers 13 and 14, whereby the transparent substrates 11 and 12 are warmed.

  In the example shown in FIG. 5, the heat generating conductor 30 has a plurality of thin conductive wires 31 that connect the pair of bus bars 25. In the illustrated example, the plurality of conductive thin wires 31 are arranged along the first direction d1 and extend along the second direction d2 that is not parallel to the first direction d1. In particular, each conductive thin wire 31 extends linearly along the second direction d2. In the illustrated example, the first direction (arrangement direction) d1 and the second direction (extension direction) d2 of each conductive thin wire 31 are orthogonal to each other. Further, the plurality of conductive thin wires 31 are arranged at the same pitch P along the first direction (arrangement direction) d1.

  Examples of the material for forming the conductive thin wire 31 include gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, nickel-chromium alloy, and rhenium. -One or more alloys (not including a metal oxide) containing one or more of these metals such as a tungsten alloy and a nickel-tungsten alloy can be exemplified.

  By the way, what used transparent conductive thin films, such as ITO (Indium Tin Oxide), is conventionally known as a conductor for heat_generation | fever. However, such a transparent conductive thin film is liable to be cracked or disconnected due to its thinness. In the present embodiment, a conductive thin wire 31 made of a metal material is used as the heat generating conductor 30. Although the conductive thin wire 31 made of this metal material is opaque, it has higher strength than a transparent conductive thin film, and is less likely to cause cracks or disconnection. On the other hand, there is a possibility that the visibility and the daylighting property through the transparent heating plate 10 may be impaired by the conductive thin wire 31 made of an opaque metal material. Therefore, it is preferable that the conductive thin wire 31 is made as thin as possible.

  In the example shown in FIG. 4, the width W of the conductive thin wire 31, that is, the width W along the film surface of the base film 21 can be set to 5 μm or more and 20 μm or less. According to the conductive thin wire 31 having such a width W, since the conductive thin wire 31 is sufficiently thinned, the heat-generating conductor 30 is effectively invisible, and the transparent heat generating plate 10 is good. Visibility and daylighting can be imparted. Moreover, the height (thickness) H of the conductive fine wire 31, that is, the height (thickness) H along the normal direction to the film surface of the base film 21 can be set to 5 μm or more and 20 μm or less. According to the conductive thin wire 31 having such a height (thickness) H, it has sufficient electrical resistance while having an appropriate electrical resistance value (hereinafter simply referred to as resistance). Can be secured. Further, the arrangement pitch P of the conductive thin wires 31, that is, the arrangement pitch P along the arrangement direction (first direction) can be set to 0.5 mm or more and 30 mm or less. According to the conductive thin wires 31 having such an arrangement pitch P, it is possible to suppress generation of heat generation unevenness (temperature unevenness) while reducing power consumption.

  In the example shown in FIG. 4, the conductive thin wire 31 includes a first dark color layer 37 provided on the base film 21, a conductive metal layer 36 provided on the first dark color layer 37, and A second dark color layer 38 provided on the conductive metal layer 36 is included. In other words, the surface of the conductive metal layer 36 on the base film 21 side is covered with the first dark color layer 37, and the surface of the conductive metal layer 36 on the side opposite to the base film 21. A second dark color layer 38 covers the surface and both side surfaces. The dark color layers 37 and 38 may be layers having lower visible light reflectance than the conductive metal layer 36, and are dark color layers such as black. The dark color layers 37 and 38 make the conductive metal layer 36 more difficult to visually recognize.

  In the heat generating conductor 30 of the present embodiment, the heat generation amount per unit area in at least a part of the peripheral edge portion A2 of the transparent heat generating plate 10 is larger than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10. It is formed in a pattern that increases. As such a pattern, for example, in at least some of the plurality of conductive thin wires 31, the amount of heat generated per unit length varies in one conductive thin wire 31. It is done. Specifically, it corresponds to the peripheral edge portion A2 of the transparent heating plate 10 of at least a part of the conductive thin wires 31 along the extending direction of the conductive thin wires 31 (second direction d2 in FIGS. 5 and 6). The amount of heat generated per unit length of the portion is set to be higher than the amount of heat generated per unit length of the portion of the conductive thin wire 31 corresponding to the central portion A1 of the transparent heat generating plate 10. Here, the peripheral edge portion A2 of the transparent heat generating plate 10 indicates a portion corresponding to a frame-shaped region including the side edges 10a to 10d of the transparent heat generating plate 10, as shown in FIG. Further, the central portion A1 of the transparent heat generating plate 10 refers to a portion corresponding to a region surrounded by the frame-shaped peripheral edge portion A2 of the transparent heat generating plate 10.

In the example shown in FIGS. 5 and 6, at least a part of the conductive thin wires 31 has a wide portion 31 a corresponding to the central portion A <b> 1 of the transparent heat generating plate 10 along the extending direction d <b> 2 and a transparent heat generating plate. And a narrow portion 31b corresponding to ten peripheral portions A2. In a particularly illustrated example, all of the conductive thin wire 31 has a narrow portion 31b having a wide portion 31a and a relatively narrow width W ₂ having a relatively wide width W _1.

  In the example shown in FIGS. 5 and 6, the wide portion 31a and the narrow portion 31b of the conductive thin wire 31 are made of the same material. When the constituent materials are the same and the height is the same, the resistance value increases as the width of the conductive thin wire 31 is narrower, that is, the cross-sectional area is smaller. Therefore, the resistance value in the narrow part 31b of the conductive thin wire 31 is larger than the resistance value in the wide part 31a.

In general, the calorific value Q in the wiring is, according to Joule's law, the current flowing in the wiring is I, the wiring resistance is R, and the time is t.
Q = I ² × R × t
It can be expressed.
In addition, the resistance value R of each wiring is represented by ρ as the volume specific (electric) resistance value of the wiring material, L as the wiring length, W as the wiring width, and H as the wiring thickness.
R = ρ × {L / (W × H)}
It can be expressed.
That is, when the wiring height H and the material (volume specific resistance value ρ) are the same, the width W becomes smaller (the cross-sectional area W × H becomes smaller) and the resistance value R becomes larger. The calorific value Q increases.

  Therefore, the heat generation amount per unit length of the narrow portion 31b of the conductive thin wire 31 is higher than the heat generation amount per unit length of the wide portion 31a of the conductive thin wire 31. Thereby, the calorific value per unit area in the peripheral edge A2 of the transparent heat generating plate 10, particularly the peripheral edge A2 corresponding to the side edges 10a and 10c of the transparent heat generating plate 10, is reduced per unit area in the central portion A1 of the transparent heat generating plate 10. The calorific value becomes higher.

Such width _{W 1} of the wide portion 31a of the electroconductive thin line 31 may be, for example 10μm or 20μm or less. The width _W of the narrow portion 31b of the electroconductive thin line 31 _2, for example, be a 10μm less a range of 5 [mu] m. According to the conductive thin wire 31 having such widths W ₁ and W ₂ , the width W ₂ of the narrow portion 31b is sufficiently smaller than the width W ₁ of the wide portion 31a. The calorific value per unit length in can be made sufficiently high. The length of the narrow portion 31b along the second direction (extending direction) d2 can be 5 mm or more and 100 mm or less. In addition, you may design so that the length along the 2nd direction d2 of the narrow part 31b may become longer, so that the dimension (area) of the transparent heat generating plate 10 becomes large. According to the conductive thin wire 31 having such a narrow width portion 31b, the temperature of the peripheral edge portion A2 of the transparent heating plate 10 can be appropriately maintained while suppressing an increase in power consumption.

  Next, an example of a method for manufacturing the transparent heating plate 10 will be described with reference to FIGS. 7-13 is sectional drawing which shows an example of the manufacturing method of the transparent heat generating board 10 in order.

  First, the sheet-like base film 21 is prepared. The base film 21 is an electrically insulating resin base that is transparent and generally transparent to transmit wavelengths (380 nm to 780 nm) in the visible light wavelength band.

  Next, as shown in FIG. 7, a first dark color layer 37 is provided on the base film 21. For example, a physical vapor deposition method (PVD method) such as a vacuum deposition method, a sputtering method, or an ion plating method, a chemical vapor deposition method (CVD method), a liquid phase growth method such as a plating method, or these two methods. The first dark color layer 37 can be provided on the base film 21 by a method combining the above. Various known materials can be used as the material of the first dark color layer 37. Examples thereof include copper nitride, copper oxide, nickel nitride, black nickel, black copper oxide (cupric oxide), black iron oxide (triiron tetroxide), and the like.

  Next, as shown in FIG. 8, a conductive metal layer (conductive layer) 36 is provided on the first dark color layer 37. As described above, the conductive metal layer 36 is made of one or more of gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, and an alloy containing one or more of these metals. It is a layer. The conductive metal layer 36 can be formed by a known method. For example, a method of attaching a metal foil such as copper foil using a weather-resistant adhesive, a physical vapor deposition method (PVD method) such as a vacuum deposition method, a sputtering method, an ion plating method, a chemical vapor phase, etc. A liquid phase growth method such as a growth method (CVD method) or a plating method, or a method combining two or more of these can be employed.

  In the case where the conductive metal layer 36 is formed of a metal foil such as a copper foil, the first dark color layer 37 is first formed on one surface of the metal foil, and the metal on which the first dark color layer 37 is formed. The foil may be laminated on the base film 21 through, for example, an adhesive layer or an adhesive layer so that the first dark color layer 37 faces the base film 21. In this case, for example, a part of the material forming the metal foil is subjected to a darkening process (blackening process), and the first dark color layer 37 made of metal oxide or metal sulfide is formed from the part forming the metal foil. can do. Moreover, you may make it provide the 1st dark color layer 37 on the surface of metal foil like a coating film of a dark color material, plating layers, such as nickel and chromium. Alternatively, the first dark color layer 37 may be provided by roughening the surface of the metal foil.

  Next, as shown in FIG. 9, a resist pattern 41 is provided on the conductive metal layer 36. The resist pattern 41 is a pattern corresponding to the pattern of the heat generating conductor 30 to be formed. In the method described here, the resist pattern 41 is provided only on the portion finally forming the heat generating conductor 30. The resist pattern 41 can be formed by patterning using a known photolithography technique.

  Next, as shown in FIG. 10, the conductive metal layer 36 and the first dark color layer 37 are etched using the resist pattern 41 as a mask. By this etching, the conductive metal layer 36 and the first dark color layer 37 are patterned into a pattern substantially the same as the resist pattern 41. The etching method is not particularly limited, and a known method can be employed. Examples of known methods include wet etching using an etching solution such as ferric chloride aqueous solution and hydrochloric acid, and plasma etching. Thereafter, as shown in FIG. 11, the resist pattern 41 is removed.

  Then, as shown in FIG. 12, the 2nd dark color layer 38 is formed in the surface on the opposite side of the base film 21 of a conductive metal layer 36, and both side surfaces. 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.

  As described above, the heat generating conductor 30 is formed on the base film 21. Thereafter, a pair of bus bars 25 is formed, and the sheet with conductor 20 is produced. The bus bar 25 can be formed by various methods such as a method of attaching a metal foil, a method using a photolithography technique similar to that of the heat generating conductor 30, and a method by screen printing. Further, the bus bar 25 may be formed simultaneously with the heat generating conductor 30. In this case, in the step of providing the resist pattern 41 described with reference to FIG. 9 described above, the resist pattern 41 may be formed in a pattern corresponding to the pattern of the heat generating conductor 30 and the bus bar 25 to be formed.

  Finally, the first transparent substrate 11, the bonding layer 13, the conductor-attached sheet 20, the bonding layer 14, and the second transparent substrate 12 are superposed in this order, and heated and pressurized. In the example shown in FIG. 13, first, the bonding layer 13 is temporarily bonded to the first transparent substrate 11, and the bonding layer 14 is temporarily bonded to the second transparent substrate 12. Next, the first transparent substrate 11 and the conductor on which the bonding layer 13 is temporarily bonded so that the side on which the bonding layers 13 and 14 of the transparent substrates 11 and 12 are temporarily bonded faces the sheet 20 with the conductor, respectively. The attached sheet 20 and the second transparent substrate 12 to which the bonding layer 14 is temporarily bonded are superposed in this order, and heated and pressurized. Thereby, the 1st transparent substrate 11, the sheet | seat 20 with a conductor, and the 2nd transparent substrate 12 are joined via the joining layers 13 and 14, and the transparent heat generating board 10 shown in FIG. 4 is manufactured.

  The transparent heat generating plate 10 of the present embodiment described above includes the transparent substrates 11 and 12 and the heat generating conductor 30 that is laminated with the transparent substrates 11 and 12 and generates heat when a voltage is applied, and is transparent. The heat generation amount per unit area in at least a part of the peripheral edge portion A2 of the heat generating plate 10 is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10. In particular, the heat-generating conductor 30 has a plurality of conductive thin wires 31, and at least some of the plurality of conductive thin wires 31 have a heat generation amount per unit length of one conductive thin wire. It has changed in 31. Specifically, the width of at least some of the plurality of conductive thin wires 31 changes along the extending direction d <b> 2 of the conductive thin wires 31.

  According to such a transparent heat generating plate 10, the peripheral edge portion A <b> 2 of the transparent heat generating plate 10, which is easily deprived of heat by the frame member 5, is suppressed from becoming lower temperature than the central portion A <b> 1 of the transparent heat generating plate 10. be able to. That is, the temperature distribution in the transparent heat generating plate 10 can be effectively made uniform. Thereby, the transparent heat generating plate 10 can sufficiently exhibit the antifogging, snow melting or defrosting function even in the peripheral edge portion A2.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings as appropriate. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as the above embodiment, A duplicate description is omitted.

  A modification of the heat generating conductor 30 of the transparent heat generating plate 10 will be described with reference to FIG. FIGS. 14A and 14B are diagrams corresponding to FIG. 6, and are enlarged views showing modifications of the heat generating conductor 30.

  In the example shown in FIG. 14A, the wide portion 31a of the conductive thin wire 31 has a notch 32 formed along the extending direction (second direction) d2. In the illustrated example, the wide portion 31a of the conductive thin wire 31 has one cutout portion 32 along the extending direction d2, and the first conductive portion 31a1 and the second conductive portion are provided through the cutout portion 32. The portions 31a2 are arranged in the arrangement direction (first direction) d1. Each of the conductive portions 31a1 and 31a2 is connected to the narrow portion 31b at the end along the extending direction d2.

In the illustrated example, the width W ₁₁ along the film surface of the base film 21 of the first conductive portion 31a1 of the wide portion 31a, the width W ₁₂ along the film surface of the base film 21 of the second conductive portion 31a2, and, the width W ₂ along the film surface of the base film 21 of the narrow portion 31b is arranged to satisfy the following relation.
W ₁₁ + W ₁₂ > W ₂

  In the conductive thin wire 31 that satisfies this relationship, when the wide portion 31a and the narrow portion 31b have the same height, the cross-sectional area of the narrow portion 31b is equal to the cross-sectional area of the entire wide portion 31a (first conductive portion 31a1 and Smaller than the sum of the cross-sectional areas of the second conductive portions 31a2. That is, the resistance value of the narrow portion 31b is larger than the resistance value of the entire wide portion 31a. Therefore, even with the conductive thin wire 31 having such a wide portion 31 a, the heat generation amount per unit length of the narrow portion 31 b of the conductive thin wire 31 is about the unit length of the wide portion 31 a of the conductive thin wire 31. The calorific value becomes higher. Thereby, the heat generation amount per unit area in the peripheral edge portion A2 corresponding to the side edges 10a and 10c of the transparent heat generating plate 10 is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10.

  In addition, the notch part 32 is not restricted to what is continuously formed along the extending direction d2, For example, the notch part 32 may be formed intermittently along the extending direction d2, or a notch part 32 may be formed only in part along the extending direction d2. In addition, a plurality of notches 32 may be arranged along the arrangement direction d1. That is, three or more conductive parts may be arranged along the arrangement direction d1.

  In the example shown in FIG. 14B, the conductivity per unit length along the extending direction (second direction) d2 of the conductive thin wire 31 in the portion corresponding to the peripheral edge portion A2 of the transparent heating plate 10. The wiring length of the thin wire 31 is longer than the wiring length of the conductive thin wire 31 per unit length along the extending direction d2 of the conductive thin wire 31 corresponding to the central portion A1 of the transparent heating plate 10. In particular, in the illustrated example, the portion of the conductive thin wire 31 corresponding to the central portion A1 of the transparent heating plate 10 is configured as a straight portion 31c, and the portion of the conductive thin wire 31 corresponding to the peripheral portion A2 of the transparent heating plate 10. Is configured as a polygonal line portion 31d.

  In the illustrated example, the wiring length per unit length along the extending direction d2 in the broken line portion 31d corresponding to the peripheral edge portion A2 of the transparent heat generating plate 10 is a straight line corresponding to the central portion A1 of the transparent heat generating plate 10. It is longer than the wiring length per unit length along the extending direction d2 in the portion 31c. Accordingly, the heat generation amount per unit length along the extending direction d2 in the broken line portion 31d is higher than the heat generation amount per unit length along the extending direction d2 in the straight line portion 31c.

  Therefore, even with such a conductive thin wire 31, the amount of heat generated per unit length along the extending direction (second direction) d2 in the portion corresponding to the peripheral edge A2 of the transparent heat generating plate 10 is reduced. It becomes higher than the calorific value per unit length along the extending direction d2 in the portion corresponding to the central portion A1. Thereby, the heat generation amount per unit area in the peripheral edge portion A2 corresponding to the side edges 10a and 10c of the transparent heat generating plate 10 is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10.

  In the example shown in FIG. 14B, the portion of the conductive thin wire 31 corresponding to the peripheral edge A2 of the transparent heat generating plate 10 is not limited to the one formed by a broken line, but may be another shape such as a wavy line. There may be. Moreover, the part corresponding to center part A1 of the transparent heat generating plate 10 of the electroconductive thin wire 31 is not restricted to what is comprised with a straight line, Other shapes, such as a broken line and a wavy line, may be sufficient.

  Next, another modification of the heat generating conductor 30 of the transparent heat generating plate 10 will be described with reference to FIG.

  In the example shown in FIG. 15, the heat generation amount per unit length of some of the conductive thin wires 31 among the plurality of conductive thin wires 31 corresponds to the unit length of any of the other conductive thin wires 31. It is different from the calorific value. In the illustrated example, the width of a part of the plurality of conductive thin wires 31 is different from the width of any one of the other conductive thin wires 31. In particular, in the illustrated example, the width of the conductive thin wire 31 corresponding to the peripheral edge A <b> 2 of the transparent heating plate 10 among the plurality of conductive thin wires 31 is narrower than the width of the other conductive thin wires 31. Thus, the heat generation amount per unit length of the conductive thin wire 31 corresponding to the peripheral edge portion A2 of the transparent heat generating plate 10 among the plurality of conductive thin wires 31 is the conductive property corresponding to the central portion A1 of the transparent heat generating plate 10. The amount of heat generated per unit length of the thin wire 31 is higher.

In the example shown, it is arranged corresponding to the peripheral portion A2, and at least one narrow thin wire 31f has a relatively narrow width W ₄ are arranged corresponding to the center portion A1, a relatively wide and a least one of the wide thin lines 31e having a W _3. In particular, in the illustrated example, the peripheral edge A2 corresponding to the side edge 20b has a plurality of narrow thin wires 31f arranged at a pitch P and spaced apart in the first direction d1, and the peripheral edge corresponding to the side edge 20d. In the portion A2, a plurality of narrow thin wires 31f arranged at a pitch P apart from each other in the first direction d1 are provided. In addition, a plurality of wide thin wires 31e arranged at a pitch P spaced apart in the first direction d1 are provided so that a part thereof is disposed in the central portion A1.

Width _{W 4} of the width _{W 3} and a narrow thin line 31f of the wide fine line 31e satisfies the following relationship.
W ₃ > W ₄
In the conductive thin wire 31 satisfying this relationship, when the wide thin wire 31e and the narrow thin wire 31f have the same height, the cross-sectional area of the narrow thin wire 31f is smaller than the cross-sectional area of the wide thin wire 31e. That is, the resistance value in the narrow thin line 31f is larger than the resistance value in the wide thin line 31e. Therefore, the heat generation amount per unit length of the narrow thin wire 31f is higher than the heat generation amount per unit length of the wide thin wire 31e. Thereby, the heat generation amount per unit area in the peripheral edge portion A2 corresponding to the side edges 10b and 10d of the transparent heat generating plate 10 is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10.

The width W ₃ of such a wide thin line 31e can be set to be 10 μm or more and 20 μm or less, for example. Further, the narrow fine lines 31f width _{W 4} of the may be, for example less than 5μm or 10 [mu] m. According narrower fine line 31f having a wide fine line 31e and the width _{W 4} having such a width _{W 3,} which is sufficiently small width _{W 4} of the narrow thin line 31f is compared to the width _{W 3} of the wide fine line 31e Therefore, the calorific value per unit length in the narrow thin wire 31f can be made sufficiently high.

  Next, still another modification of the heat generating conductor 30 of the transparent heat generating plate 10 will be described with reference to FIG.

In the example shown in FIG. 16, the arrangement pitch of at least some of the plurality of conductive thin wires 31 changes along the arrangement direction d1. In the illustrated example, the arrangement pitch P ₂ along the arrangement direction (first direction) d1 between the plurality of conductive thin wires 31 corresponding to the peripheral edge portion A2 of the transparent heating plate 10 among the plurality of conductive thin wires 31. but between the plurality of conductive thin wires 31 corresponding to the center portion A1 of the transparent heating plate 10, it is narrower than the array direction arrangement pitch P ₁ along a (first direction) d1. Thereby, the heat generation amount per unit area in the peripheral edge portion A2 corresponding to the side edges 10b and 10d of the transparent heat generating plate 10 is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10.

  With reference to FIG. 17, still another modification of the heat generating conductor 30 of the transparent heat generating plate 10 will be described.

In the example shown in FIG. 17, the plurality of conductive thin wires 31 of the heat generating conductor 30 correspond to the wide portion 31 a having a relatively wide width W ₁ and the peripheral portion A 2 of the transparent heat generating plate 10. and a narrow portion 31b having a narrow width W ₂ in. The arrangement pitch along the arrangement direction (first direction) d1 between the plurality of conductive thin wires 31 corresponding to the peripheral edge A2 of the transparent heat generating plate 10 among the plurality of conductive thin wires 31 of the heat generating conductor 30. P ₂ is, between the plurality of conductive thin wires 31 corresponding to the center portion A1 of the transparent heating plate 10, it is narrower than the array direction arrangement pitch P ₁ along a (first direction) d1.

  Therefore, the heat generation amount per unit area in the peripheral edge portion A2 corresponding to the side edges 10a and 10c of the transparent heat generating plate 10 is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10 and is transparent. The amount of heat generated per unit area at the peripheral edge A2 corresponding to the side edges 10b and 10d of the heat generating plate 10 is higher than the amount of heat generated per unit area at the central portion A1 of the transparent heat generating plate 10. That is, in the frame-shaped peripheral edge portion A2 corresponding to the side edges 10a to 10d of the transparent heat generating plate 10, the heat generation amount per unit area is higher than the heat generation amount per unit area in the central portion A1 of the transparent heat generating plate 10. Become.

  According to the transparent heat generating plate 10 having the heat generating conductor 30 as described above, the central portion A1 of the transparent heat generating plate 10 with respect to the entire frame-shaped peripheral edge A2 of the transparent heat generating plate 10 that is easily deprived of heat by the frame member 5. It can suppress that it becomes low temperature compared with. That is, the temperature distribution in the transparent heat generating plate 10 can be more effectively uniformized. Thereby, the transparent heat generating plate 10 can fully exhibit the antifogging, snow melting, or defrosting function in the entire frame-shaped peripheral edge portion A2.

  As yet another modification, in the above-described embodiment, each thin conductive wire 31 extends in a linear pattern along the extending direction (second direction) d2, but is not limited thereto, The thin thin wire 31 may extend in a pattern such as a wavy line or a broken line along the extending direction d2. Further, the heat generating conductor 30 is not limited to the one formed by an aggregate of a plurality of conductive thin wires 31 that connect the pair of bus bars 25, and forms a mesh pattern that connects the pair of bus bars 25. It may be formed of a conductive thin wire.

  As yet another modification, in the above-described embodiment, the cross-sectional area of the conductive thin wire 31 is changed by changing the width W of the conductive thin wire 31, thereby changing the resistance value of the conductive thin wire 31. However, the present invention is not limited to this. For example, the cross-sectional area of the conductive thin wire 31 is changed by changing the height (thickness) H of the conductive thin wire 31, and the resistance value of the conductive thin wire 31 is thereby changed. It may be changed. Further, the resistance value of the conductive thin wire 31 may be made different by changing the material constituting the conductive thin wire 31.

  In addition to windows for various buildings such as houses, offices, stores, hospitals, etc., the transparent heat generating plate 10 has a portion having a transparent portion that partitions the interior and the exterior, for example, a door (glass door), a partition, a wall surface. (Transparent wall) can also be used. Moreover, it is not restricted to what partitions the inside and the outside, such as a window, a door, and a partition, It can also be used for the general use for buildings, such as a window and a door which have a transparent part inside a building, a partition window of a bathtub, and a skylight.

  Further, the transparent heat generating plate 10 includes windows for vehicles such as automobiles, railways, aircrafts, ships, spacecrafts, traffic signal windows installed at road intersections and along railway tracks, signboards and display devices installed outdoors. You may use for a window (protection board) etc.

  In addition, although several modifications with respect to embodiment mentioned above were demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

DESCRIPTION OF SYMBOLS 1 Window 5 Frame member 7 Power supply 10 Transparent heating plate 10a Side edge 10b Side edge 10c Side edge 10d Side edge 11 First transparent substrate 12 Second transparent substrate 13 Bonding layer 14 Bonding layer 15 Wiring part 20 Sheet 21 with conductor Film 25 Bus bar 30 Heat-generating conductor 31 Conductive thin wire 31a Wide portion 31b Narrow portion 31c Linear portion 31d Broken line portion 31e Wide thin wire 31f Narrow thin wire 36 Conductive metal layer 37 First dark color layer 38 Second dark color layer 41 Resist pattern A1 Center part A2 Peripheral part d1 First direction d2 Second direction

Claims (9)

A transparent heating plate comprising a transparent substrate and a heating conductor that is laminated with the transparent substrate and generates heat when a voltage is applied,
The heat generating conductor is provided at a peripheral portion and a central portion of the transparent heat generating plate,
Before the amount of heat generated per unit area in at least a portion of the distichum edge is higher than the amount of heat generated per unit area in front Symbol in central part, transparent heating plate. The transparent substrate has a first transparent substrate and a second transparent substrate that are stacked on each other,
The transparent heat generating plate according to claim 1, wherein the heat generating conductor is disposed between the first transparent substrate and the second transparent substrate.   The transparent heat generating plate according to claim 1, wherein the heat generating conductor has a plurality of conductive thin wires.   The transparent heat generating plate according to claim 3, wherein at least some of the plurality of conductive thin wires have a calorific value per unit length changing in one conductive thin wire.   The transparent heat generating plate according to claim 4, wherein the width of at least some of the plurality of conductive thin wires changes along the extending direction of the conductive thin wires.   The calorific value per unit length of some of the plurality of conductive thin wires is different from the calorific value per unit length of any of the other conductive thin wires. The transparent heating plate according to any one of 5.   The transparent heating plate according to claim 6, wherein a width of a part of the plurality of conductive thin wires is different from a width of any one of the other conductive thin wires.   The transparent heat generating plate according to any one of claims 3 to 7, wherein an arrangement pitch of at least some of the plurality of conductive thin wires changes along an arrangement direction thereof.   A window comprising: the transparent heat generating plate according to claim 1; and a frame member in contact with at least a part of the periphery of the transparent heat generating plate.

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