JP2016143540A - Sheet with conductor used for heating plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet with a conductor used for a heating plate, which improves invisibility of a heating wire and is capable of spotlessly removing fogging on window glass and snow and water adhering to window glass.SOLUTION: A sheet 20 with a conductor is a sheet with a conductor which is used for a heating plate that generates heat with an application of a voltage. The sheet with a conductor includes a transparent base material 30, and a conductive pattern 40 provided on the transparent base material and including a conductive thin wire. In the sheet with a conductor, an infrared absorbent 32 is contained in the transparent base material, or a layer including an infrared absorbent is provided as a layer separate from the transparent base material and the conductive pattern.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a sheet with a conductor used for a heating plate, a heating plate provided with a sheet with a conductor, and a vehicle including the heating plate.

  2. Description of the Related Art Conventionally, as a defroster device used for a window glass such as a front window and a rear window of a vehicle, an apparatus in which a heating wire made of a tungsten wire is arranged on the entire window glass is known (for example, see Patent Document 1 and Patent Document 2) ). In this prior art, a heating wire arranged on the entire window glass is energized, and the window glass is heated by resistance heating (Joule heat) to remove fogging of the window glass, or on the window glass. It is possible to secure the sight of the occupant by melting the adhering snow and ice or evaporating the water droplets.

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

  As described above, the conventional defroster device uses a tungsten wire as the heating wire. In this case, in order to prevent the electric resistance of the heating wire from becoming too high due to the high electrical resistivity of tungsten, the sectional area of the heating wire is increased. Therefore, the heating wire using a tungsten wire is easily visually recognized by an observer. Visibility of the heating wire by an observer such as a driver deteriorates the visibility of the observer through the window glass.

  In response to the above problems, the applicant has proposed in the previous application that the invisibility of the heating wire of the defroster device can be improved by using a conductive thin wire made of a metal having a lower electrical resistance than tungsten. In addition, when a conductive thin wire made of a metal having a low electrical resistance as described above is used as the heating wire of the defroster device, the performance of the defroster can be improved by including an infrared absorber separately from the heating wire. As a result, it was found that fogging of the window glass and snow and ice attached to the window glass could be removed without any spots. The present invention is based on such knowledge. Therefore, the object of the present invention is to improve the invisibility of the heating wire, and to a heating plate that can remove the fogging of the window glass and snow and ice adhering to the window glass without any spots. It is providing the sheet | seat with an electric conductor used.

The sheet with a conductor according to the present invention is a sheet with a conductor used for a heating plate that generates heat when a voltage is applied,
A transparent substrate;
Provided on the transparent substrate, comprising a conductive pattern including a conductive thin wire,
An infrared absorber is contained in the transparent substrate, or a layer containing an infrared absorber is provided as a layer separate from the transparent substrate and the conductive pattern.

  The sheet with a conductor according to the present invention may further include a holding layer between the transparent substrate and the conductive pattern, and the holding layer may include an infrared absorber.

  In the sheet with a conductor according to the present invention, a layer containing the infrared absorber may be provided between the transparent substrate and the conductive pattern.

  In the sheet with a conductor according to the present invention, the layer containing the infrared absorber may be provided on a side opposite to the side on which the conductive pattern of the transparent substrate is provided.

  In the sheet with a conductor according to the present invention, the infrared absorber may contain a cesium-tungsten composite oxide.

  In the sheet with a conductor according to the present invention, the cesium-tungsten composite oxide may have an average dispersed particle size of 800 nm or less.

  Moreover, according to another embodiment of the present invention, a heat generating plate provided with a pair of glass plates and a sheet with a conductor disposed between the pair of glass plates, and a vehicle provided with the heat generating plate are also provided. .

  According to the sheet with a conductor of the present invention, in a heat generating plate used as a defroster device for an automobile or the like, the invisibility of the heating wire is improved, and the fogging of the window glass and the snow and ice adhering to the window glass are eliminated. Can be removed.

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 provided with a heat generating plate as an example of a vehicle. FIG. 2 is a view of the heat generating plate as viewed from the normal direction of the plate surface. 3 is a cross-sectional view of the heat generating plate of FIG. FIG. 4 is a cross-sectional view showing an example of a sheet with a conductor. FIG. 5 is a cross-sectional view showing another example of a sheet with a conductor. FIG. 6 is a cross-sectional view showing another example of a sheet with a conductor. FIG. 7 is a plan view showing an example of the pattern shape of the conductive pattern of the heat generating plate. FIG. 8 is a plan view showing another example of the pattern shape of the conductive pattern of the heat generating plate. FIG. 9 is an enlarged view showing a part of the conductive pattern of FIG. FIG. 10 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 11 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 12 is a diagram for explaining a modification of the method for manufacturing the heat generating plate. FIG. 13 is a diagram for explaining another modification of the method for manufacturing the 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, a “sheet with a conductor” is a concept including a member that can be called a plate or a film. Therefore, a “sheet with a conductor” is a “conductive pattern plate (substrate)” or a “conductive pattern”. It cannot be distinguished from a member called “film” only by the difference in designation.

  In addition, “sheet surface (plate surface, film surface)” means a target sheet-like member (plate-like) when the target sheet-like (plate-like, film-like) member is viewed as a whole and globally. It refers to the surface that coincides with the plane direction of the member or film-like member.

  In this specification, “joining” includes not only “main joining” that completely completes joining but also so-called “temporary joining” for temporarily fixing before “main joining”.

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

  1-13 is a figure for demonstrating one Embodiment by this invention. First, the heat generating plate provided with the conductor-attached sheet will be described. 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 diagram of the heat generating plate of FIG. It is a cross-sectional view.

  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 composed of a heat generating plate 10 is illustrated. The automobile 1 has a power source 7 such as a battery.

  FIG. 2 shows the heat generating plate 10 viewed from the normal direction of the plate surface. Moreover, the cross-sectional view corresponding to the III-III line of the heat generating plate 10 of FIG. 2 is shown in FIG. In the example shown in FIG. 3, the heat generating plate 10 includes a pair of glass plates 11 and 12, a sheet 20 with a conductor disposed between the pair of glass plates 11 and 12, and the glass plates 11 and 12 and the conductive plate 10. It has the joining layers 13 and 14 which join the sheet | seat 20 with a body. In the example shown in FIGS. 1 and 2, the heat generating plate 10 is curved. However, in FIGS. 3 and 10 to 13, the heat generating plate 10 and the heat generating plate 10 are shown for simplification and easy understanding. The glass plates 11 and 12 are illustrated in a flat plate shape.

  The sheet with conductor 20 includes a sheet-like transparent base material 30, a conductive pattern 40 formed on the transparent base material 30, a wiring portion 15 made of copper wire or the like for energizing the conductive pattern 40, A connection portion 16 (also called a bus bar or a bus bar electrode) that connects the conductive pattern 40 and the wiring portion 15 is provided. Although the conductive pattern 40 may be provided directly on the transparent base material 30, the conductive pattern 40 may be provided on the transparent base material 30 via the holding layer 31 in order to improve the adhesion between the two. The wiring part 15 functions as a wiring for electrically connecting the conductive pattern 40 to the power source 7 such as a battery. In the example shown in FIGS. 2 and 3, the conductive pattern 40 is energized through the wiring portion 15, and the conductive pattern 40 is heated by resistance heating. The heat generated in the conductive pattern 40 is transmitted to the glass plates 11 and 12 through the bonding layers 13 and 14, and the glass plates 11 and 12 are warmed. Thereby, the cloudiness by the dew condensation adhering to the glass plates 11 and 12 can be removed. Moreover, when snow and ice adhere to the glass plates 11 and 12, this snow and ice can be melted. Therefore, a passenger | crew's visual field is ensured favorable.

  In the example shown in FIGS. 2 and 3, the conductive pattern 40 is energized from the power source 7 such as a battery via the wiring portion 15 and the connection portion 16, and the conductive pattern 40 is heated by resistance heating. The heat generated in the conductive pattern 40 is transmitted to the glass plates 11 and 12 through the bonding layers 13 and 14, and the glass plates 11 and 12 are warmed. Thereby, the cloudiness by the dew condensation adhering to the glass plates 11 and 12 can be removed. Moreover, when snow and ice adhere to the glass plates 11 and 12, this snow and ice can be melted. Therefore, a passenger | crew's visual field is ensured favorable.

  In particular, when the glass plates 11 and 12 are used for a front window of an automobile, it is preferable to use a glass plate having a high visible light transmittance so as not to obstruct the view of the passenger. Examples of the material of the glass plates 11 and 12 include soda lime glass (blue plate glass), borosilicate glass (white plate glass), quartz glass, soda glass, potash glass, and the like. The glass plates 11 and 12 preferably have a transmittance in the visible light region of 90% or more. Here, the visible light transmittance of the glass plates 11 and 12 is 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 plates 11 and 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 glass plates 11 and 12 have a thickness of 1 mm or more and 5 mm or less. With such a thickness, the glass plates 11 and 12 excellent in strength and optical characteristics can be obtained.

  The glass plates 11 and 12 and the conductor-attached sheet 20 are bonded via bonding layers 13 and 14, respectively. 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 0.7 mm or less, respectively.

  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. One functional layer may exhibit two or more functions. For example, the glass plates 11 and 12 of the heat generating plate 10, the bonding layers 13 and 14, and the transparent base of the sheet 20 with a conductor to be described later. A function may be imparted to at least one of the materials 30. Examples of functions that can be imparted to the heating 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 a polarization function. An antifouling function and the like can be exemplified.

  Next, the sheet with conductor 20 will be described. As shown in FIG. 4, the conductor-attached sheet 20 includes a sheet-like transparent base material 30, a holding layer 31 laminated on the transparent base material 30, and a conductive pattern 40 formed on the holding layer 31. The wiring portion 15 for energizing the conductive pattern 40 and the connection portion 16 for connecting the conductive pattern 40 and the wiring portion 15 are provided. In the embodiment as shown in FIG. 4, the infrared absorber may be contained in the transparent base material 30 or may be contained in the holding layer 31, or the transparent base material 30 and the holding layer. Infrared absorber 32 may be contained in both 31. The infrared absorber 32 will be described later.

  The conductor-attached sheet 20 has substantially the same planar dimensions as the glass plates 11 and 12 and may be disposed over the entire heat generating plate 10 or may be disposed on a part of the heat generating plate 10 such as a front portion of a driver seat. May be arranged only.

  The sheet-like transparent substrate 30 functions as a substrate that supports the holding layer 31 and the conductive pattern 40. The transparent base material 30 is an electrically insulating substrate that is transparent in general terms and transmits a wavelength (380 nm to 780 nm) in the visible light wavelength band. In the example shown in FIGS. 2, 7, and 8, the transparent substrate 30 has substantially the same dimensions as the glass plates 11 and 12 and has a substantially trapezoidal planar shape.

  The resin contained in the transparent substrate 30 may be any resin as long as it transmits visible light and can appropriately support the holding layer 31 and the conductive pattern 40, but preferably a thermoplastic resin is used. it can. Examples of the thermoplastic resin include acrylic resins such as polymethyl methacrylate, polyester resins such as polyvinyl chloride, polyethylene terephthalate, amorphous polyethylene terephthalate (A-PET), and polyethylene naphthalate (PEN), polyethylene, polypropylene, and polymethyl. Examples thereof include polyolefin resins such as pentene and cyclic polyolefin, cellulose resins such as triacetyl cellulose (cellulose triacetate), polystyrene, polycarbonate resin, AS resin and the like. In particular, acrylic resin and polyvinyl chloride are preferable because they are excellent in etching resistance, weather resistance, and light resistance. In order to make the transparent substrate 30 have an infrared absorbent, when the transparent resin is produced by forming a resin as described above, the infrared absorbent 32 is dispersed in the resin and kneaded by an extrusion melt film forming machine or the like. By doing so, the infrared absorber 32 can be uniformly dispersed in the transparent substrate 30. When the infrared absorbent 32 is contained in the transparent base material 30, it is preferable to contain the infrared absorbent so as to be 1 to 25% by mass with respect to the mass of the transparent base material. If it is this range, the improvement of a defroster function and visible-light transmittance can be made to make compatible.

  In addition, the transparent substrate 30 preferably has a thickness of 0.03 mm or more and 0.3 mm or less in consideration of retention of the conductive pattern 40, light transmission, and the like.

  The holding layer 31 has a function of improving the bondability between the transparent substrate 30 and the conductive pattern 40 and holding the conductive pattern 40. The holding layer 31 can be formed by, for example, laminating a transparent electrically insulating resin sheet on the transparent substrate 30, or can be formed by applying a resin material on the transparent substrate 30. . As such a holding layer 31, for example, polyvinyl butyral (PVB), a two-component curable urethane adhesive, a two-component curable epoxy adhesive, or the like can be used. As will be described later, when the transparent substrate 30 is peeled after the conductor-attached sheet 20 is joined (temporarily joined) to the glass plate 11 via the joining layer 13, the release layer is included in the holding layer 31. May be. The holding layer 31 may also contain an infrared absorber.

  The thickness of the holding layer 31 can be set to 1 μm or more and 100 μm or less in consideration of light transmittance, bondability between the transparent substrate 30 and the conductive pattern 40, and the like. Preferably, the thickness of the holding layer 31 can be 1 μm or more and 15 μm or less.

  As described above, in the present invention, the infrared absorber 32 is included in any one of the transparent substrate 30, the holding layer 31, the layer 33 containing the infrared absorber 32, or two or more of these layers. Yes. Thus, the function as a defroster of a heat generating plate can be improved more by containing the infrared absorber 32 in the layer which comprises the sheet | seat 20 with a conductor. The reason for this is not clear, but the infrared absorbent 32 absorbs part of the heat rays that pass through the heat generating plate, and the temperature of the entire layer containing the infrared absorbent 32 (for example, the transparent substrate 30) rises uniformly. This is considered to improve the function of the heat generating plate as a defroster in combination with heat generated from the conductive pattern. Moreover, if the infrared absorber 32 is contained in any one layer of the conductor-attached sheet 20, if applied to a windshield of an automobile or the like, it is possible to suppress an increase in temperature in the vehicle such as in summer.

  As the infrared absorber, a conventionally known material can be used as long as it can absorb electromagnetic waves in the infrared wavelength band. In the present invention, particularly, electromagnetic waves (near infrared rays) in the wavelength range of 780 to 3000 nm are absorbed. It is preferable to use a material that can be used. As such a material, either or both of an organic infrared absorber and an inorganic infrared absorber can be used. Among these, it is preferable to use composite tungsten oxide fine particles known as inorganic infrared absorbers. The composite tungsten oxide fine particles have a general formula: MxWyOz (wherein, M element is H, He, alkali metal, alkaline earth metal, rare earth element, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, One or more elements selected from Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, 0.001 ≦ x / y ≦ 1.1 2.2 ≦ z / y ≦ 3.0). Such a composite tungsten oxide is a material that can absorb electromagnetic waves (near infrared rays) in the wavelength range of 800 to 1100 nm, and functions as an infrared absorber.

  The composite tungsten oxide fine particles represented by the general formula MxWyOz are excellent in durability when having a hexagonal, tetragonal, or cubic crystal structure, and are therefore selected from the hexagonal, tetragonal, and cubic crystals. Preferably it contains one or more crystal structures. For example, in the case of composite tungsten oxide fine particles having a hexagonal crystal structure, preferable M elements include Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn. Examples thereof include composite tungsten oxide fine particles containing one or more selected elements. Among these, the element M is preferably Cs (cesium) from the viewpoint of durability.

In the above general formula, the addition amount x of M element to be added is preferably 0.001 or more and 1.0 or less, and more preferably around 0.33. The value of x theoretically calculated from the hexagonal crystal structure is 0.33, and preferable infrared absorption characteristics can be obtained with addition amounts around this value. On the other hand, the abundance z of oxygen is preferably 2.2 or more and 3.0 or less. For example, Cs _0.33 WO ₃ , Rb _0.33 WO ₃ , K _0.33 WO ₃ , Ba _0.33 WO _{3 and the} like can be mentioned. These composite tungsten oxide fine particles may be used alone or in combination.

  In addition, it is preferable that the surface of the composite tungsten oxide fine particles is coated with an oxide containing one or more elements of Si, Ti, Zr, and Al from the viewpoint of further improving weather resistance. .

  The average dispersed particle size of the composite tungsten oxide fine particles is preferably 800 nm or less, more preferably 200 nm or less, and particularly preferably 100 nm or less, from the viewpoint of keeping the sheet with conductor transparent. In view of difficulty in production, uniform dispersibility in the material to be incorporated, etc., the average dispersed particle size is preferably 30 nm or more. In addition, the average dispersed particle size here means a volume average particle size, and can be measured using a particle size distribution / particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device manufactured by Nikkiso Co., Ltd.). it can.

  In addition, as a layer other than the transparent substrate 30, the holding layer 31, and the conductive pattern 40, a layer 33 containing an infrared absorber may be provided separately. The layer 33 containing the infrared absorber may be provided, for example, between the transparent base material 30 and the conductive pattern 40, and the side opposite to the side where the conductive pattern 40 of the transparent base material 30 is provided. It can also be provided. Further, as shown in FIG. 5, a layer 33 containing an infrared absorber 32 may be provided between the transparent substrate 30 and the conductive pattern 40. Alternatively, as shown in FIG. The layer 33 containing the infrared absorber 32 may be provided on both the side opposite to the side where the conductive pattern 40 is provided.

  The layer 33 containing the infrared absorber 32 can be formed by dispersing the above-described infrared absorber in an appropriate resin. The resin can be used without particular limitation as long as it has high transparency. For example, a polyester resin, a polyurethane resin, an acrylic resin, an epoxy resin, or the like can be used. Further, as will be described later, when the sheet with conductor 20 is the heating plate 10 disposed between the pair of glass plates 11 and 12, it is provided between the sheet with conductor 20 and the glass plate 11. 12. If the layer 33 containing the infrared absorber 32 is formed using the same material (for example, polyvinyl butyral) as the bonding layers 13 and 14, the layer 33 containing the infrared absorber 32 also serves as the bonding layers 13 and 14. It is also possible.

  Next, the conductive pattern 40 will be described with reference to FIGS. 7 and 8 are plan views of the conductor-attached sheet 20 as viewed from the normal direction of the sheet surface. FIG. 9 is an enlarged view showing a part of the conductive pattern 40 of FIG.

  The conductive pattern 40 is energized from the power source 7 such as a battery through the wiring portion 15 and the connection portion 16 and generates heat by resistance heating. And when this heat | fever is transmitted to the glass plates 11 and 12 through the joining layers 13 and 14, the glass plates 11 and 12 are warmed. In addition, although illustration is abbreviate | omitted, normally, as for the wiring part 15, the switch is inserted (connected in series) between the connection part (bus-bar electrode) 16 of the power supply 7 and the electroconductive pattern 40. FIG. The switch is closed and the conductive pattern 40 is energized only when the heating plate 10 needs to be heated. When heating of the heat generating plate 10 is not necessary, the switch is opened and the current to the conductive pattern 40 is interrupted. As the power source 7, when installed in an automobile, a battery such as an attached lead storage battery or lithium ion storage battery can be used, but a dedicated power source (battery, generator, etc.) may be used separately. In the case of a railway vehicle powered by an electric motor, electric power fed from an overhead wire can be converted into an appropriate voltage and current for use.

  FIG. 7 shows an example of the pattern shape of the conductive pattern 40. In the example shown in FIG. 7, a plurality of conductive thin wires 41 that connect the pair of connecting portions 16 are provided. In the illustrated example, each of the plurality of conductive thin wires 41 extends from one connection portion 16 to the other connection portion 16 in a wavy line pattern. The plurality of conductive thin wires 41 are arranged away from each other in a direction non-parallel to the extending direction of the conductive thin wires 41. In particular, the plurality of conductive thin wires 41 are arranged in a direction orthogonal to the extending direction of the conductive thin wires 41. Each thin conductive wire 41 may extend between the pair of connecting portions 16 in a pattern such as a straight line, a broken line, or a sine wave in addition to the wavy line pattern.

  8 and 9 show other examples of the pattern shape of the conductive pattern 40. FIG. In the example shown in FIGS. 8 and 9, the conductive thin wires 41 of the conductive pattern 40 are arranged in a mesh pattern that defines a large number of opening regions 44. The conductive pattern 40 includes a plurality of connecting elements 45 extending between the two branch points 43 and defining an open area 44. That is, the conductive thin wires 41 of the conductive pattern 40 are configured as a collection of a large number of connection elements 45 that form branch points 43 at both ends.

  In the example shown in FIGS. 8 and 9, the large number of opening regions 44 of the conductive pattern 40 are arranged in a shape and a pitch that do not have repetitive regularity (periodic regularity). In particular, in the illustrated example, a large number of open regions 44 coincide with each Voronoi region in a Voronoi diagram generated from random two-dimensionally distributed generating points distributed within an upper limit value and a lower limit value between adjacent generating points. Are arranged as follows. In other words, each connection element 45 of the conductive pattern 40 coincides with each boundary of the Voronoi region in the Voronoi diagram. Each branch point 43 of the conductive pattern 40 coincides with the Voronoi point in the Voronoi diagram. This Voronoi diagram is obtained by a known method as disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-178556, Japanese Patent Application Laid-Open No. 2013-238029, and the like. Description is omitted.

  When the conductive pattern has a large number of opening regions arranged in a shape and pitch having a repeating regularity (periodic regularity) such as a square lattice arrangement or a honeycomb arrangement, the repeating rule of the arrangement of the many opening areas Due to the nature, light glare may be visually recognized. A light beam is a predetermined streaky pattern on the heating plate when light from the opposite side of the observer is incident on the heating plate, for example, when the light of an oncoming vehicle headlight enters the front window of an automobile. In particular, when a large number of opening regions of a conductive pattern are arranged in a shape and pitch having regularity, the light spot tends to be noticeable. And when this light beam is visually recognized by an observer such as a driver, the visibility of the observer through the heat generating plate is deteriorated. On the other hand, according to the conductive pattern 40 having a large number of open regions 44 arranged in a shape and pitch that do not have repetitive regularity (periodic regularity) as shown in FIGS. It is possible to effectively suppress the occurrence of light glare on the plate 10.

  In the 30 conductive patterns 40 shown in FIGS. 8 and 9, the average number of connecting elements 45 extending from one branch point 43 is greater than 3.0 and less than 4.0. Thus, when the average number of connecting elements 45 extending from one branch point 43 is greater than 3.0 and less than 4.0, a pattern in which regularity is lost from the honeycomb arrangement can be obtained. When the average number of connecting elements 45 extending from one branch point 43 is more than 3.0 and less than 4.0, the arrangement of the opening regions 44 is made irregular so that the opening regions 44 have a repeating regularity (periodicity). Therefore, it is possible to prevent the direction in which the lamps are arranged with stability from occurring stably, and as a result, it is possible to more effectively suppress the occurrence of light glare on the heating plate 10. At the same time, since the arrangement of the connection elements 45 is based on the honeycomb arrangement, the connection elements 45 are evenly dispersed, and as a result, it is possible to effectively suppress uneven heat generation.

  Strictly speaking, the average number of connection elements 45 extending from one branch point 43 is determined by examining the number of connection elements 45 extending for all branch points 43 included in the conductive pattern 40. However, in actuality, the connection extending from one branch point 43 is considered in consideration of the size of the opening area 44 per one defined by the conductive thin wire 41 and the like. In a section having an area expected to reflect the overall trend of the number of elements 45, for a number of branch points 43 deemed appropriate in view of the degree of variation in the number of objects to be investigated, The number of connection elements 45 extending from each branch point 43 is examined to calculate an average value, and the calculated value is the average value of the number of connection elements 45 extending from one branch point 43 for the conductive pattern 40. Treat as Unishi may be. For example, an average value calculated by counting the number of connection elements 45 extending from 100 branch points 43 included in the 300 mm × 300 mm region of the conductive pattern 40 using an optical microscope or an electron microscope is used as the conductive pattern. It can be treated as an average value of the number of connection elements 45 extending from one branch point 43 for the sex pattern 40.

  In the conductive pattern 40 shown in FIGS. 8 and 9, the conductive pattern 40 includes open regions 44 surrounded by four, five, six, and seven connecting elements 45, respectively. Among the opening areas 44 included in the sex pattern 40, the opening area 44 surrounded by the six connection elements 45 is the largest. That is, the opening region 44 surrounded by the six connection elements 45 is included in the conductive pattern 40 more than the opening region 44 surrounded by the other number of connection elements 45. Yes.

  In such a conductive pattern 40, the arrangement of the opening regions 44 is an arrangement in which the regularity of the shape and arrangement of each opening region is broken from a honeycomb arrangement in which regular hexagons having the same shape are regularly arranged, in other words, In addition, it is possible to obtain an arrangement in which the shape and arrangement of each opening region are randomized with reference to the honeycomb arrangement. Thereby, it is possible to suppress the occurrence of clear roughness in the arrangement of the opening regions 44, and it is possible to distribute a large number of the opening regions 44 with a substantially uniform density, that is, with a substantially uniform distribution. As a result, heat generation unevenness can be effectively suppressed. In addition, it is possible to stably make the arrangement of the opening regions 44 completely irregular, that is, to prevent the direction in which the opening regions 44 are regularly arranged from existing. Therefore, it is possible to more effectively suppress the occurrence of light glare on the heat generating plate 10.

  Strictly speaking, the number of connection elements 45 surrounding one opening region 44 is determined by examining the number of connection elements 45 surrounding the opening region 44 for all opening regions 44 included in the conductive pattern 40. However, in actuality, the total number of connecting elements 45 surrounding one opening region 44 is considered in consideration of the size of each opening region 44 defined by the conductive thin wires 41. The number of open areas 44 that are considered appropriate in consideration of the degree of variation in the number of objects to be investigated in one section having an area that can be expected to reflect a general tendency surround each open area 44 The number of connection elements 45 may be checked, and the number of open regions 44 for each number of connection elements 45 surrounding the periphery may be integrated. For example, the number of connection elements 45 surrounding each of the 100 opening regions 44 included in the 300 mm × 300 mm region of the conductive pattern 40 is counted using an optical microscope or an electron microscope, and the connection elements 45 surrounding the periphery are counted. The conductive pattern 40 is obtained by using a value obtained by integrating the number of the opening regions 44 for each number. It can be determined how many open elements 44 are surrounded by the number of connecting elements 45.

  Examples of the material for forming the conductive pattern 40 include gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, and tungsten, and nickel. -One or more alloys of two or more metals selected from these exemplified metals such as chromium alloy, brass, bronze and the like can be exemplified.

  The conductive pattern 40 can be formed on the transparent substrate 30 (on the holding layer 31 when the holding layer 31 is present) by a conventionally known method. For example, the above-described metal foil is laminated on the transparent substrate 30 and the foil is etched into a desired pattern, or the conductive ink containing fine particles made of the above-described metal is formed on the transparent substrate 30 in a desired manner. Examples thereof include a method of printing with a pattern and plating the above-described metal thin film on the formed pattern surface. Hereinafter, a method for forming a conductive pattern by etching a foil will be described in detail.

  First, a metal foil is prepared, and a dark color film is formed on one surface of the metal foil. The metal foil forms a conductive metal layer of conductive thin wires. In addition, the dark color film forms a dark color layer of conductive thin wires. The thickness of the metal foil can be 1 μm or more and 50 μm or less. Further, by applying a darkening process (blackening process) to a part of the material forming the metal foil, and forming a film made of a metal oxide or a metal sulfide on a part of the metal foil, A dark color film can be provided on one surface. The metal foil on which the dark color film is formed is roughened by darkening treatment (blackening treatment) by laminating it with the transparent base material on which the retention layer is formed so that the dark film and the holding layer face each other. Since the resin material constituting the holding layer 31 enters the fine irregularities on the surface of the dark color film thus formed, the dark color film and the holding layer are firmly bonded to each other by a so-called anchor effect. Thereby, metal foil and a transparent base material are joined firmly.

  Next, a resist pattern is provided on the metal foil. The resist pattern is a pattern corresponding to the pattern of the conductive pattern to be formed. Such a resist pattern can be formed by patterning using a known photolithography technique. Subsequently, the metal foil including the dark color film is etched using the resist pattern as a mask. By this etching, the metal foil including the dark color film is patterned into a pattern substantially the same as the resist pattern. As the corrosive liquid used for the etching process, a known corrosive liquid can be appropriately selected and used depending on the metal foil and the material of the dark color film (when the dark color film exists). For example, when the metal foil is copper and the dark color film is copper (II) oxide (CuO), an aqueous ferric chloride solution is used for the metal foil and the dark color film, or the metal foil part (copper) is a chloride chloride. An aqueous diiron solution and dilute hydrochloric acid can be used for the dark film (copper (II) oxide) portion. Then, the sheet | seat 20 with a conductor is produced by removing a resist pattern.

  In the above-described embodiment, each of the plurality of connection elements 45 included in the conductive pattern 40 has a straight line shape (straight line portion) when viewed from the normal direction of the plate surface of the heat generating plate 10, but is not limited thereto. Instead, at least a part of the plurality of connection elements 45 may have a shape other than a straight line shape, for example, a curved line shape or a polygonal line shape when viewed from the normal direction of the plate surface of the heat generating plate 10. Specifically, it may have a shape such as an arc shape, a parabolic shape, a wavy shape, a zigzag shape, or a combination of a curve and a straight line. In particular, the connection element 45 connecting the two branch points 43 as a straight line (straight line segment) is less than 20% of the plurality of connection elements 45, that is, 80% or more of the plurality of connection elements 45. Preferably have a shape other than a straight line (straight line).

  According to the conductive pattern 40 including the connection element 45 having a shape other than a straight line (straight line), light incident on the side surface of the connection element 45 having a curved shape, a broken line shape, or the like is transmitted on the side surface. Diffuse reflection. Thereby, light incident on the side surface of the connection element 45 from a certain direction (light of the headlight of the oncoming vehicle, sunlight, etc.) may be reflected in a certain direction on the side surface corresponding to the incident direction. It is suppressed. Therefore, it can suppress that this reflected light is visually recognized by observers, such as a driver, and the conductive pattern 40 which has the connection element 45 is visually recognized by an observer. As a result, the deterioration of the visibility through the window glass by the observer due to the visual recognition of the conductive pattern 40 can be suppressed.

  Further, in the above-described embodiment, the conductive pattern 40 is determined based on the Voronoi diagram, that is, a large number of opening regions 44 are arranged in a shape and a pitch having no repeated regularity (periodic regularity). However, the conductive pattern 40 is not limited to such a pattern, and the conductive pattern 40 is a pattern in which opening regions having the same shape such as a triangle, a quadrangle, and a hexagon are regularly arranged, and an opening region having an irregular shape. Various patterns such as a pattern in which are regularly arranged may be used.

  Next, the heating element 10 using the conductor-attached sheet 20 will be described. The heat generating plate 10 can be manufactured by stacking the glass plate 11, the bonding layer 13, the conductor-attached sheet 20, the bonding layer 14, and the glass plate 12 in this order, and heating and pressing. As an example of the manufacturing method of the heat generating plate, first, the bonding layer 13 is temporarily bonded to the glass plate 11 and the bonding layer 14 is temporarily bonded to the glass plate 12, respectively. Next, the glass plate 11 and the conductor-attached sheet on which the bonding layer 13 is temporarily bonded so that the side on which the bonding layers 13 and 14 of the glass plates 11 and 12 are temporarily bonded faces the sheet 20 with conductor, respectively. 20. The glass plate 12 to which the bonding layer 14 is temporarily bonded is superposed in this order, and heated and pressurized. Thereby, the glass plate 11, the sheet | seat 20 with a conductor, and the glass plate 12 are joined via the joining layers 13 and 14, and the heat generating plate 10 shown in FIG. 3 is manufactured.

  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 in the above embodiment. A duplicate description is omitted.

  With reference to FIGS. 10-13, the modification of the manufacturing method of the heat generating plate 10 is demonstrated. 10 to 13 are cross-sectional views sequentially showing modifications of the method for manufacturing the heat generating plate 10.

  First, the conductor-attached sheet 20 is produced. The conductor-attached sheet 20 can be manufactured by the method described in the example of the manufacturing method described above.

  Next, the bonding layer 13 is temporarily bonded to the glass plate 11. Next, the glass plate 11 on which the bonding layer 13 is temporarily bonded is disposed so that the side on which the bonding layer 13 of the glass plate 11 is temporarily bonded is opposed to the sheet 20 with conductor. Superposed from the pattern 40 side, heated and pressurized. Thereby, as shown in FIG. 10, the glass plate 11 and the conductor-attached sheet 20 are bonded (temporary bonding or main bonding) via the bonding layer 13.

  Next, as shown in FIG. 11, the transparent base material 30 of the sheet with conductor 20 is removed. For example, when the holding layer 31 is formed so as to include a release layer, the transparent base material 30 of the conductor-attached sheet 20 can be peeled from the conductive pattern 40 and the bonding layer 13 using the release layer. .

  As the release layer, for example, an interfacial release type release layer, an interlayer release type release layer, a cohesive release type release layer, or the like can be used. As the interface peeling type peeling layer, a peeling layer having relatively low adhesion to the conductive pattern 40 and the bonding layer 13 as compared with the adhesion to the transparent substrate 30 can be suitably used. Examples of such a layer include a silicone resin layer, a fluororesin layer, and a polyolefin resin layer. In addition, it is possible to use a release layer that has relatively low adhesion to the transparent substrate 30 compared to adhesion to the conductive pattern 40 and the bonding layer 13. The delamination-type delamination layer includes a plurality of layers of films, and the adhesion between the plural layers is relatively low compared to the adhesion between the conductive pattern 40 and the bonding layer 13 and the transparent substrate 30. A release layer can be exemplified. Examples of the cohesive release type release layer include a release layer in which a filler as a dispersed phase is dispersed in a base resin as a continuous phase.

  When an interfacial release type release layer having a layer having relatively low adhesiveness to the conductive pattern 40 and the bonding layer 13 as compared to the adhesiveness to the transparent substrate 30 is used as the release layer, A peeling phenomenon occurs between the conductive pattern 40 and the bonding layer 13. In this case, it is possible to prevent the release layer from remaining on the conductive pattern 40 and the bonding layer 13 side. That is, the transparent substrate 30 is removed together with the release layer. When the transparent substrate 30 and the release layer are thus removed, the bonding layer 13 is exposed in the opening region 43 of the conductive pattern 40.

  On the other hand, as an exfoliation layer, when using an interfacial exfoliation type exfoliation layer having relatively low adhesion to the transparent substrate 30 compared to the adhesion between the conductive pattern 40 and the bonding layer 13, A peeling phenomenon occurs between the peeling layer and the transparent substrate 30. As a release layer, it has a multi-layer film, and is a delamination type in which the adhesion between the plurality of layers is relatively low compared to the adhesion with the conductive pattern 40 and the bonding layer 13 and the transparent substrate 30. When a release layer is used, a peeling phenomenon occurs between the plurality of layers. In the case of using an agglomerated exfoliation type release layer in which a filler as a dispersed phase is dispersed in a base resin as a continuous phase, an exfoliation phenomenon due to a cohesive failure occurs in the exfoliation layer.

  Finally, the glass plate 12 is superimposed on the glass plate 11, the bonding layer 13, and the conductive pattern 40 via the bonding layer 14, and heated and pressurized. Specifically, the bonding layer 14 is temporarily bonded to the glass plate 12, and then the side of the glass plate 12 on which the bonding layer 14 is temporarily bonded is opposed to the conductive pattern 40 and the bonding layer 13. 11. The glass plate 12 to which the conductive pattern 40, the bonding layer 13, and the bonding layer 14 are temporarily bonded is superposed in this order, and heated and pressed. Thereby, the glass plate 11, the conductive pattern 40, and the glass plate 12 are joined (main joining) via the joining layers 13 and 14, and the heat generating plate 10 shown in FIG. 12 is manufactured.

  According to the heat generating plate 10 shown in FIG. 12, even when the heat generating plate 10 is manufactured using the conductor-attached sheet 20, the transparent base material 30 can be prevented from being included in the heat generating plate. . Thereby, the thickness of the heat generating plate 10 as a whole can be reduced. In addition, the number of interfaces in the heat generating plate 10 can be reduced. Accordingly, it is possible to suppress a decrease in optical characteristics, that is, a decrease in visibility.

  Next, another modification of the method for manufacturing the heat generating plate 10 will be described with reference to FIG. FIG. 13 is a cross-sectional view sequentially illustrating another modification of the method for manufacturing the heat generating plate 10.

  First, the glass plate 11 and the conductor-attached sheet 20 are bonded (temporarily bonded) via the bonding layer 13 by the same process as that of the modified example of the manufacturing method of the heating plate 10 described above. The transparent substrate 30 is removed. That is, the glass plate 11, the conductive pattern 40, and the bonding layer 13 which are described with reference to FIG. 16 in the modification of the method for manufacturing the heat generating plate 10 are obtained.

  Next, the glass plate 11, the bonding layer 13, the conductive pattern 40, and the glass plate 12 are superposed in this order, and heated and pressurized. Thereby, the glass plate 11 and the conductive pattern 40 are bonded (main bonding) via the bonding layer 13, and the glass plate 11 and the glass plate 12 are bonded (main bonding) via the bonding layer 13. . And the heat generating plate 10 shown in FIG. 13 is manufactured.

  According to the heat generating plate 10 shown in FIG. 13, even when the heat generating plate 10 is manufactured using the conductor-attached sheet 20, the heat generating plate 10 does not include the transparent base material 30 and the bonding layer 14. can do. Thereby, the thickness of the heat generating plate 10 as a whole can be further reduced. In addition, the number of interfaces in the heat generating plate 10 can be further reduced. Therefore, it is possible to more effectively suppress a decrease in optical characteristics, that is, a decrease in visibility. In addition, since the conductive pattern 40 and the glass plate 12 are in contact, the heating efficiency of the glass plate 12 by the conductive pattern 40 can be increased.

  The heat generating plate 10 may be used for a rear window, a side window, or a sunroof of the automobile 1. In addition to automobiles, railroad vehicles, airplanes, ships, spacecrafts and other vehicles, offices, stores, hospital buildings, refrigerators, display boxes, cupboards, etc. It may be used.

  Furthermore, the heat generating plate 10 can be used not only for a vehicle but also for a part that divides the room from the outside, for example, a transparent part of a building or a store, a window or door of a house, or the like.

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

DESCRIPTION OF SYMBOLS 1 Automobile 5 Front window 7 Power supply 10 Heat generating plate 11 Glass plate 12 Glass plate 13 Bonding layer 14 Bonding layer 15 Wiring part 16 Connection part 20 Sheet 30 with a conductor Transparent base material 31 Holding layer 40 Conductive pattern 43 Branch point 44 Opening area 45 Connection elements

Claims (8)

A sheet with a conductor used for a heating plate that generates heat when a voltage is applied,
A transparent substrate;
Provided on the transparent substrate, comprising a conductive pattern including a conductive thin wire,
The sheet | seat with a conductor provided with the layer containing an infrared absorber as a layer different from the said transparent substrate and the said electroconductive pattern in which the infrared absorber is contained in the said transparent base material.   The sheet with a conductor according to claim 1, further comprising a holding layer between the transparent substrate and the conductive pattern, wherein the holding layer includes an infrared absorber.   The sheet | seat with an electric conductor of Claim 1 in which the layer containing the said infrared absorber is provided between the said transparent base material and the said electroconductive pattern.   The sheet | seat with an electric conductor of Claim 1 with which the layer containing the said infrared absorber is provided in the opposite side to the side in which the said electroconductive pattern of the said transparent base material was provided.   The sheet | seat with an electric conductor as described in any one of Claims 1-4 in which the said infrared absorber contains a cesium-tungsten complex oxide.   The sheet with an electric conductor according to any one of claims 1 to 5, wherein an average dispersed particle size of the cesium-tungsten composite oxide is 800 nm or less. A heating plate using the sheet with a conductor according to any one of claims 1 to 6,
A pair of glass plates;
And a sheet with a conductor disposed between the pair of glass plates.   A vehicle comprising the heat generating plate according to claim 7.

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