CN113290987A

CN113290987A - Transparent heating composite material and preparation method and application thereof

Info

Publication number: CN113290987A
Application number: CN202110345707.6A
Authority: CN
Inventors: 杜宇; 邓飞; 辛培培; 张玲
Original assignee: Shenzhen Cone Technology Co ltd
Current assignee: Shenzhen Cone Technology Co ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2021-08-24
Anticipated expiration: 2041-03-31
Also published as: CN113290987B

Abstract

The invention relates to a transparent heating composite material and a preparation method and application thereof. The preparation method of the transparent heating composite material comprises the following steps: obtaining a first transparent substrate, and forming a groove with a specified pattern on the first transparent substrate; preparing conductive heating slurry; filling the conductive heating slurry into the groove; drying the first transparent base material filled with the conductive heating slurry to form a heating circuit with a specified pattern on the first transparent base material; and obtaining a second transparent base material, paving the second transparent base material on the first transparent base material with the heating circuit, and laminating the first transparent base material and the second transparent base material into a whole to prepare the transparent heating composite material with the heating circuit. The transparent heating composite material is light and thin, high in light transmittance and high in heating efficiency.

Description

Transparent heating composite material and preparation method and application thereof

Technical Field

The invention relates to the technical field of materials, in particular to a transparent heating composite material and a preparation method and application thereof.

Background

Under the condition of large temperature difference between the inside and the outside of the automobile, the surface of the windshield of the common automobile is easy to fog to influence the visual field of a driver, and the safety of automobile driving is greatly reduced.

At present, the windshield mainly has the effect that the windshield is not easy to fog by additionally arranging a metal heating resistance wire or a transparent heating film between two pieces of glass, however, the arrangement of the metal heating resistance wire is often dense, the visual field of a driver is easily influenced, the driving safety of a vehicle is influenced, and the additionally arranged heating resistance wire is easy to make the automobile glass thicker; although the transparent heating film has high visible light transmittance, the automobile glass is easily thicker by additionally arranging the transparent heating film between the two pieces of glass.

Disclosure of Invention

Therefore, the transparent heating composite material prepared by the preparation method is not easy to additionally increase the thickness of the automobile windshield, and is beneficial to improving the driving safety of the automobile and reducing the energy consumption.

A preparation method of a transparent heating composite material comprises the following steps:

obtaining a first transparent substrate, and forming a groove with a specified pattern on the first transparent substrate;

preparing conductive heating slurry;

filling the conductive heating slurry into the groove;

drying the first transparent base material filled with the conductive heating slurry to form a heating circuit with a specified pattern on the first transparent base material; and

and obtaining a second transparent base material, paving the second transparent base material on the first transparent base material on which the heating circuit is formed, and laminating the first transparent base material and the second transparent base material into a whole to prepare the transparent heating composite material which is clamped with the heating circuit.

In one embodiment, the step of forming the groove with the specified pattern on the first transparent substrate includes the following operations:

after a release film is laid on the first transparent substrate, the first transparent substrate and the release film are imprinted according to a specified pattern through the release film, and the release film and the groove corresponding to the specified pattern are formed.

In one embodiment, the step of filling the conductive heat emitting paste into the groove comprises the following operations:

and coating the conductive heating slurry on the first transparent substrate paved with a release film corresponding to the specified pattern, so that the conductive heating slurry flows into the groove through the release film.

In one embodiment, after the step of drying the first transparent substrate filled with the conductive heating paste, a step of removing the release film is further included.

In one embodiment, the depth of the groove is formed to be 10-20 μm; and/or the width of the groove is 2 mm-10 mm.

In one embodiment, the conductive heating paste is a carbon nanotube conductive heating paste, and the preparation of the conductive heating paste comprises the following steps:

mixing the carbon nano tube, the transparent conductive material, the dispersing agent and the organic solvent, and fully dispersing to obtain the conductive heating slurry.

In one embodiment, the aspect ratio of the carbon nanotube is 1000-5000; and/or the presence of a catalyst in the reaction mixture,

the transparent conductive material is selected from at least one of poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid, polyacetylene, polyaniline, polypyrrole, polythioether and poly-p-phenylene.

In one embodiment, the mass ratio of the carbon nanotubes to the transparent conductive material, the dispersant and the organic solvent is (2.5-10): (2.5-15): (1-5): (70-96).

In one embodiment, the material of the first transparent substrate and the material of the second transparent substrate are each independently selected from one of glass and transparent resin.

In one embodiment, the step of bonding the first transparent substrate and the second transparent substrate into a whole comprises:

and placing an adhesive layer between the first transparent substrate and the second transparent substrate, and fixing the first transparent substrate and the second transparent substrate by the adhesive layer.

In one embodiment, the material of the bonding layer is selected from at least one of polyvinyl butyral and ethylene-vinyl acetate copolymer, and the thickness of the bonding layer is 0.4 mm-2.4 mm.

In one embodiment, before the first transparent substrate and the second transparent substrate are bonded into a whole, a step of providing a conductive member electrically connected to the heat generating circuit is further included.

A transparent heating composite material is prepared by the preparation method of the transparent heating composite material.

An automobile windshield is prepared from the transparent heating composite material.

Drawings

FIG. 1 is a flow chart illustrating the preparation of one embodiment of a transparent exothermic composite;

fig. 2 is a top view of a first transparent substrate prepared with a heating circuit and a conductive member.

Fig. 3 is a schematic partial cross-sectional view of a transparent heat-generating composite according to an embodiment.

Reference numerals:

10. a transparent heat-generating composite material; 110. a first transparent substrate; 120. a second transparent substrate; 130. a heating circuit; 140. a bonding layer; 150. a conductive member; 200. a release film; 300. conductive heating slurry.

Detailed Description

The present invention will now be described more fully hereinafter for purposes of facilitating an understanding thereof, and may be embodied in many different forms and are not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. When the terms "vertical," "horizontal," "left," "right," "upper," "lower," "inner," "outer," "bottom," and the like are used to indicate an orientation or positional relationship, it is for convenience of description only based on the orientation or positional relationship shown in the drawings, and it is not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Referring to fig. 1 and fig. 2, one embodiment of the present invention provides a method for preparing a transparent heat-generating composite material 10, which includes steps a to e, specifically:

step a: a first transparent substrate 110 is obtained, and a groove with a predetermined pattern is formed on the first transparent substrate 110.

Alternatively, the material of the first transparent substrate 110 is selected from one of glass and transparent resin. In an alternative specific example, the material of the first transparent substrate 110 is tempered glass or semi-tempered glass. Of course, in other embodiments, the material of the first transparent substrate 110 is not limited to the above, and may be other transparent materials.

In the present embodiment, the first transparent substrate 110 is in a sheet shape; the thickness of the first transparent substrate 110 is 3mm to 5 mm. Of course, in other embodiments, the shape of the first transparent substrate 110 is not limited to a sheet shape, and may be any other shape; the thickness of the first transparent substrate 110 is not limited to the above, and can be adjusted according to actual requirements.

Specifically, the step of forming the groove with the predetermined pattern on the first transparent substrate 110 includes the following operations:

after the release film 200 is laid on the first transparent substrate 110, the first transparent substrate 110 and the release film 200 are engraved together in a predetermined pattern through the release film 200. With first transparent substrate 110 with from the same imprinting of type membrane 200, can guarantee to be identical from the figure that type membrane 200 and first transparent substrate 110 surface formed, when guaranteeing follow-up coating conductive heating slurry 300, conductive heating slurry 300 can be accurate fill to the recess of first transparent substrate 110 in, and can protect first transparent substrate 110 not to have the recess surface not damaged, reduce the influence of coating process to the luminousness of the transparent composite material 10 that generates heat that makes.

Alternatively, the imprinting of the first transparent substrate 110 and the release film 200 may be made by engraving. Such as laser engraving.

Optionally, the release film 200 is made of polytetrafluoroethylene and has a thickness of 10 μm to 20 μm. Of course, the material of the release film 200 is not limited to teflon, but may be other materials; the thickness of the release film 200 is not limited to the above, and can be adjusted according to actual requirements.

It is understood that the pattern of the grooves of the first transparent substrate 110 is designed according to the shape of the heat generating circuit 130 to be prepared. In one specific example, the thickness and width of the groove are the thickness and width of the heat generating circuit 130.

In one embodiment, the groove of the first transparent substrate 110 is folded back and forth, and the heat-generating circuit 130 is folded back and forth. By configuring the heating circuit 130 as a reciprocating folding structure, the heating can be more uniform, and the heat can be prevented from being concentrated in the central area. In one specific example, the groove is S-shaped and the heat generating circuit 130 is S-shaped. Of course, the shape of the groove is not limited to the above, and may be other patterned lines.

In another embodiment, the grooves are regular grooves. For example, a rectangular groove, in which case the heat generating circuit 130 is a film. Alternatively, the thickness of the heating circuit 130 is 10 μm to 20 μm. When the heating circuit 130 is a film, the heating area is larger, and the used slurry contains fewer heating materials, so that the cost can be lower.

Optionally, the thickness of the groove is 10 μm to 20 μm; the width of the groove is 2 mm-10 mm. Further, the thickness of the groove is 15-20 μm; the width of the groove is 4 mm-8 mm. When the thickness of the groove is set according to the above, the transparent heating composite material 10 can ensure excellent transparency and heating capability without increasing the thickness of the heating circuit 130 to improve the heating capability, and the heating circuit is not easy to deform in subsequent processing; the width of the heat-generating circuit 130 is set as described above so that the transparent heat-generating composite material 10 can further improve transparency. The region where the heat generating circuit 130 is located may be a part of the transparent heat generating composite material 10. For example, the plurality of grooves are intermittently disposed, so that the heating circuits 130 in the grooves are disposed on the first transparent substrate 110 at intervals, and the plurality of heating circuits 130 are electrically connected through the transparent conductive circuit, so that the transparent heating composite material 10 has a defogging/frosting function through the combined action of the plurality of heating circuits 130. Alternatively, only a partial region of the entire transparent heat generating composite material 10 needs defogging/frosting, and in this case, the heat generating circuit 130 is disposed only in the region. Of course, the heating circuit 130 may be disposed on the whole transparent heating composite material 10 according to actual requirements.

Step b: the conductive heating paste 300 is prepared.

Specifically, the conductive heat emitting paste 300 is a paste having a conductive heat emitting capability. Optionally, the conductive heating paste 300 is a carbon nanotube conductive heating paste 300.

Optionally, the conductive heating paste 300 is a carbon nanotube conductive heating paste 300, and the preparation of the carbon nanotube conductive heating paste 300 includes the following steps: the carbon nanotube, the transparent conductive material, and the dispersant are mixed in an organic solvent and sufficiently dispersed to obtain the carbon nanotube conductive heating slurry 300. Optionally, the mass ratio of the carbon nanotubes to the transparent conductive material and the dispersant is (2.5-10): (2.5-15): (1-5).

The carbon nanotubes serve as a heat generating material in the above conductive heat generating paste 300. The length-diameter ratio of the carbon nano tube is set to be 1000-5000, so that the carbon nano tube can be well dispersed in the conductive heating slurry 300, and can be better bridged and overlapped into a network shape after being dispersed, thereby being beneficial to transfer and transmission of electric charges and improving the heating efficiency of the transparent heating layer 130. In an alternative specific example, the carbon nanotube has an aspect ratio of 1000, 1200, 1500, 1800, 2000, 2200, 2500, 2800, 3000, 3200, 3500, 3800, 4000, 4200, 4500, 4800, or 5000. Further, the length-diameter ratio of the carbon nano tube is 3000-5000. It should be noted that, the aspect ratio of the carbon nanotube herein refers to the ratio of the length to the outer diameter of the carbon nanotube.

In some embodiments, the carbon nanotubes have a tube diameter of 6nm to 10 nm. The carbon nano tubes with the tube diameters distributed in the range have better consistency, and are favorable for improving the conductive stability. In an alternative specific example, the carbon nanotubes have a diameter of 6nm, 6.5nm, 7nm, 7.5nm, 8nm, 8.5nm, 9nm, or 10 nm. Further, the diameter of the carbon nanotube is 8nm to 10 nm. It should be noted that the tube diameter of the carbon nanotube herein refers to the outer diameter of the carbon nanotube.

The transparent conductive material serves as a conductive substance in the conductive heat emitting paste 300, so that the carbon nanotube can be electrically connected to a power supply to emit heat. Optionally, the transparent conductive material is a transparent conductive organic. The transparent conductive organic substance has a certain viscosity, which is beneficial to the adhesion between the transparent heating layer and the first transparent substrate 110 and the second transparent substrate 120. In addition, compared with other transparent conductive materials, the transparent conductive organic matter has high conductivity, can form a conjugate effect with the carbon nano tube to cause the change of the electron cloud density between the transparent conductive layer and the carbon nano tube, is beneficial to the improvement of the conductive performance of the transparent conductive layer, and simultaneously forms a chemical connection with smaller contact resistance, and can promote the improvement of the conductive performance of the carbon nano tube, so that the heat production requirement of anti-fogging can be met by adding a small amount of carbon nano tube, and the anti-fogging function is realized; and because the content of the carbon nano tube is low, a network structure is formed in the heating circuit 130, a new conductive channel is formed, the conductive performance and transparency of the heating circuit 130 are also effectively improved, and the heating circuit 130 obtained by curing has high transparency and heating stability. In an alternative specific example, the transparent conductive material is selected from at least one of poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid, polyacetylene, polyaniline, polypyrrole, polythioether and polyparaphenylene. Of course, in other embodiments, the transparent conductive material is not limited to the above, and may be other transparent and conductive substances.

The dispersant plays a role of dispersing in the above composition, so that the carbon nanotubes and the transparent conductive material are uniformly dispersed in the prepared conductive heat emitting paste 300. Optionally, the dispersant is selected from at least one of polyvinylpyrrolidone, carboxymethyl cellulose, ethyl cellulose, and nanocellulose. Of course, the dispersant is not limited to the above, and may perform a dispersing function without affecting the heat generation efficiency and light transmittance of the heat generating circuit 130 manufactured using the above conductive heat generating paste 300.

Further, the mass ratio of the carbon nano tube to the transparent conductive material to the dispersant is (5.5-10): (10-15): (1-5). The carbon nanotubes are easy to agglomerate, if the carbon nanotubes cannot be sufficiently dispersed, the contact area of the carbon nanotubes and the transparent conductive material is limited, so that the final contact resistance is large, the carbon nanotubes are agglomerated together, the transparency is reduced, the heat is not uniform, and the final conductive heating capacity is low. The mass ratio of the carbon nano tube to the transparent conductive material to the dispersing agent is set according to the above, so that the carbon nano tube and the transparent conductive material are uniformly dispersed in the system respectively, and the electric charge is favorably transported between the carbon nano tube and the transparent conductive material, so that the light transmittance and the heating capacity of the conductive heating slurry 300 can be ensured when the conductive heating slurry is used, and the rapid heating can be realized only by using lower heating power while the high definition of the conductive heating slurry is maintained. Meanwhile, the content of the carbon nanotubes is moderate under the proportion, and on the premise of complete dispersion, the conductive heating slurry 300 is favorable for flowing and forming, so that the transparent heating layer cannot be formed due to over-dilution, and the conductive heating slurry 300 is difficult to fill a mold due to over-thickening. Furthermore, the mass ratio of the carbon nano tube to the transparent conductive material to the dispersant is (5.5-10): (12-15): (1-5).

Of course, the conductive heat emitting paste 300 further includes an organic solvent. Optionally, the organic solvent is at least one of ethylene glycol, butyl glycol ether, and propylene glycol methyl ether. The mass ratio of the carbon nano tube to the transparent conductive material, the dispersant and the organic solvent is (2.5-5): (2.5-15): (1-5): (70-96). In an optional specific example, the conductive heating paste 300 is composed of carbon nanotubes, a transparent conductive material, a dispersant and an organic solvent, wherein the mass ratio of the carbon nanotubes to the transparent conductive material, the dispersant and the organic solvent is (2.5-5): (2.5-15): (1-5): (70-96), the diameter of the carbon nano tube is 6-10 nm. Further, the mass ratio of the carbon nanotubes to the transparent conductive material, the dispersant and the organic solvent is (5.5-10): (12-15): (1-5): (80-90).

Specifically, the carbon nanotubes, the transparent conductive material, and the dispersant are mixed in an organic solvent, and the mixture is sufficiently dispersed by using an electromagnetic stirring method, a homogenizer, or the like. Of course, the method of dispersion is not limited to the above in other embodiments, and other feasible dispersion methods are also possible as long as the carbon nanotubes and the transparent conductive material can be uniformly and sufficiently dispersed in the conductive heat emitting paste 300 to avoid re-agglomeration.

The conductive heating paste 300 can ensure that the heating circuit 130 prepared from the conductive heating paste 300 has high heating efficiency and high light transmittance through the matching of the carbon nano tube, the transparent conductive material and the dispersing agent, so that the glass containing the heating circuit 130 is not easy to fog, and has good light transmittance, high safety and low energy consumption.

Step c: the conductive heat emitting paste 300 is filled into the groove.

Specifically, the step of filling the conductive heat emitting paste 300 into the groove includes the operations of:

on the first transparent substrate 110 on which the release film 200 corresponding to a prescribed pattern is laid, the conductive heating paste 300 is coated so that the conductive heating paste 300 is permeated into the groove through the release film 200. Specifically, the method of coating the conductive heat emitting paste 300 includes a brush coating method, a spray coating method, a blade coating method, a printing method, and the like. Of course, in other embodiments, the method of applying the conductive heat emitting paste 300 is not limited to the above, and other possible application methods may be used as long as the conductive heat emitting paste 300 can be uniformly filled into the groove through the release film 200.

Step d: the first transparent substrate 110 filled with the conductive heating paste 300 is dried to form the heating circuit 130 having a prescribed pattern on the first transparent substrate 110.

Optionally, the baking temperature is 50-70 ℃; the baking time is 50-60 min. The conductive heating paste 300 is baked according to the above parameters by adopting a proper baking temperature and baking time, so that the solvent of the conductive heating paste 300 can be completely volatilized, the heating circuit 130 can be uniformly laid on the first transparent base material 110, the defect of the inside of the transparent heating layer caused by the too fast volatilization of the solvent can not be caused, the combination stability of the carbon nano tube and the transparent conductive polymer is not good enough, and the problem of the conductive heating capability of the final heating circuit 130 is influenced.

It can be understood that after the groove of the first transparent substrate 110 is filled with the conductive heating paste 300, the thickness of the conductive heating paste 300 can be flush with the release film 200, and after the baking is finished, due to the volatilization of the organic solvent, the heating circuit 130 is flush with the top of the groove, so that the thickness of the heating circuit 130 is exactly the same as the depth of the groove. The cured conductive heat emitting paste 300 remaining on the release film 200 is also removed along with the removal of the release film 200.

In this embodiment, the transparent heat-generating composite material 10 further includes a conductive member 150 for electrically connecting to a power source. Therefore, before the second transparent substrate 120 is attached to the first transparent substrate 110 with the heating circuit 130, a step of preparing a conductive member 150 electrically connected to the heating circuit 130 on the first transparent substrate 110 is further included.

In one embodiment, the step of preparing conductive member 150 includes: coating conductive paste on the first transparent substrate 110 provided with the heating circuit 130 according to a predetermined shape, and connecting the conductive paste with the heating circuit 130 so that the conductive member 150 can be electrically connected with the heating circuit 130; and baking the conductive paste to prepare the conductive member 150. Optionally, the baking temperature is 70-80 ℃; the baking time is 50-70 min. Baking the conductive paste according to the above parameters can make the conductive member 150 stably connected to the heating circuit 130, and is not easily loosened during subsequent processing and use. The shape of conductive device 150, the composition of the conductive paste and the thickness of the coating are as described above, and will not be described herein. It is understood that in some embodiments, the baking steps for preparing the heat generating circuit 130 and preparing the heat conductive member may be combined. That is, the conductive heating paste 300 and the conductive paste are coated on the first transparent substrate 110, and then the first transparent substrate 110 coated with the conductive heating paste 300 and the conductive paste is baked, thereby preparing the heating circuit 130 and the conductive device 150.

In another embodiment, conductive member 150 is a wire. For example, a copper wire, the conductive member 150 is electrically connected to the heating circuit 130. At this time, after the heat generating circuit 130 is prepared, it is cooled, and then the wire is connected (e.g., soldered) to the heat generating circuit 130.

And e, obtaining a second transparent base material 120, paving the second transparent base material 120 on the baked first transparent base material 110, and bonding the two transparent base materials into a whole, thereby preparing the transparent heating composite material 10 with the heating circuit 130 sandwiched in the middle.

Alternatively, the material of the second transparent substrate 120 is selected from one of glass and transparent resin. In an alternative specific example, the material of the second transparent substrate 120 is tempered glass or semi-tempered glass. Of course, in other embodiments, the material of the second transparent substrate 120 is not limited to the above, and may be other transparent materials. In an alternative specific example, the material of the first transparent substrate 110 and the second transparent substrate 120 are both glass. Of course, in other embodiments, the materials of the first transparent substrate 110 and the second transparent substrate 120 are not limited to the above, and may be other transparent materials.

In this embodiment, the second transparent substrate 120 is also in a sheet shape. The thickness of the second transparent substrate 120 is 3mm to 5 mm. Of course, in other embodiments, the shape of the first transparent substrate 110 and the second transparent substrate 120 is not limited to a sheet shape, and may be any other shape; the thicknesses of the first transparent substrate 110 and the second transparent substrate 120 are not limited to the above, and may be adjusted according to actual requirements.

In this embodiment, the step of bonding the second transparent base 120 to the first transparent base 110 on which the heat-generating circuit 130 is formed, the second transparent base 120 being a glass substrate, includes: the adhesive layer 140 is laid on the heating circuit 130; the second transparent substrate 120 is placed on the bonding layer 140, and the first transparent substrate 110 and the second transparent substrate 120 are bonded by using a molding process to prepare the transparent heating composite material 10. Alternatively, the molding process is autoclave molding or extrusion molding. In a specific example, the molding process is autoclave molding, wherein the molding conditions are that the temperature is 50 ℃ to 80 ℃ and the pressure is 0.6MPa to 0.9 MPa. Of course, the molding process is not limited to the above, and may be other molding processes commonly used in the art.

The preparation method of the transparent heating composite material 10 is simple and direct, does not depend on expensive equipment, and has low preparation cost, and the prepared transparent heating composite material 10 has high light transmittance and high heating efficiency.

The transparent heating composite material 10 has the advantages of being not easy to fog, high in light transmittance, high in heating efficiency, small in energy consumption, light and thin. Therefore, the above-described transparent heat-generating composite material 10 can be applied to a process of manufacturing automobiles. Therefore, an embodiment of the present invention also provides an application of the above-mentioned transparent heat-generating composite material 10 in manufacturing automobiles.

Referring to fig. 3, an embodiment of the present invention further provides a transparent heat-generating composite material 10, the transparent heat-generating composite material 10 is prepared by the above method for preparing the transparent heat-generating composite material, and the transparent heat-generating composite material 10 has high heat-generating efficiency and high light transmittance, and is not easy to fog in an environment with a large temperature difference (for example, an internal and external environment of an automobile in winter). Specifically, the transparent heating composite material 10 includes a first transparent substrate 110, a second transparent substrate 120 and a heating circuit 130, wherein a groove is distributed on the first transparent substrate 110, the heating circuit 130 is located in the groove, the second transparent substrate 120 is located on one side of the first transparent substrate 110 where the groove is located, and the first transparent substrate 110 is fixedly connected with the second transparent substrate 120.

Alternatively, the material of the first transparent substrate 110 is selected from one of glass and transparent resin. Alternatively, the material of the second transparent substrate 120 is selected from one of glass and transparent resin. In an alternative specific example, the material of the first transparent substrate 110 and the second transparent substrate 120 are both glass. Of course, in other embodiments, the materials of the first transparent substrate 110 and the second transparent substrate 120 are not limited to the above, and may be other transparent materials.

In the present embodiment, the first transparent substrate 110 is in a sheet shape; the second transparent substrate 120 is also in the form of a sheet. The thickness of the first transparent substrate 110 is 3mm to 5 mm; the thickness of the second transparent substrate 120 is 3mm to 5 mm. Of course, in other embodiments, the shape of the first transparent substrate 110 and the second transparent substrate 120 is not limited to a sheet shape, and may be any other shape; the thicknesses of the first transparent substrate 110 and the second transparent substrate 120 are not limited to the above, and may be adjusted according to actual requirements.

In one embodiment, the groove is in a reciprocating folding shape, and the heating circuit 130 is in a reciprocating folding structure. By configuring the heating circuit 130 as a reciprocating folding structure, the heating can be more uniform, and the heat can be prevented from being concentrated in the central area. In one specific example, the groove is S-shaped and the heat generating circuit 130 is S-shaped. Of course, the shape of the heat generating circuit 130 is not limited to the above, and may be other patterned lines.

The heat generating circuit 130 is made of a conductive heat generating paste 300 made of a heat generating composition. Specifically, the heating composition comprises carbon nanotubes, a transparent conductive material and a dispersing agent, wherein the mass ratio of the carbon nanotubes to the transparent conductive material to the dispersing agent is (2.5-10): (2.5-15): (1-5), the diameter of the carbon nano tube is 6-10 nm.

The carbon nanotubes are used as a heat-generating material in the heat-generating composition. The length-diameter ratio of the carbon nano tube is set to be 1000-5000, so that the conductive heating slurry 300 can be well dispersed, and can be better bridged and overlapped into a network shape after being dispersed, and the transfer and transmission of charges are facilitated. In an alternative specific example, the carbon nanotube has an aspect ratio of 1000, 1200, 1500, 1800, 2000, 2200, 2500, 2800, 3000, 3200, 3500, 3800, 4000, 4200, 4500, 4800, or 5000. Further, the length-diameter ratio of the carbon nano tube is 3000-5000. It should be noted that, the aspect ratio of the carbon nanotube herein refers to the ratio of the length to the outer diameter of the carbon nanotube.

In some embodiments, the diameter of the carbon nanotube is 6nm to 10nm, and the carbon nanotube with the diameter distributed in the range has good consistency, which is beneficial to improving the conductive stability. In an alternative specific example, the tube diameter of the carbon nanotube is 6nm, 6.5nm, 7nm, 7.5nm, 8nm, 8.5nm, 9nm, or 10 nm. Furthermore, the tube diameter of the carbon nano tube is 8 nm-10 nm. It should be noted that the tube diameter of the carbon nanotube herein refers to the outer diameter of the carbon nanotube.

The transparent conductive material serves as a conductive substance in the heat-generating composition, so that the carbon nanotubes can be electrically connected with a power supply to generate heat. Optionally, the transparent conductive material is a transparent conductive organic. The transparent conductive organic material has a certain viscosity, which facilitates the adhesion between the heating circuit 130 and the first transparent substrate 110 and the second transparent substrate 120. In addition, compared with other transparent conductive materials, the transparent conductive organic matter has high conductivity, can form a conjugate effect with the carbon nano tube to cause the change of the electron cloud density between the transparent conductive layer and the carbon nano tube, is beneficial to the improvement of the conductive performance of the transparent conductive layer, and simultaneously forms a chemical connection with smaller contact resistance, and can promote the improvement of the conductive performance of the carbon nano tube, so that the heat production requirement of anti-fogging can be met by adding a small amount of carbon nano tube, and the anti-fogging function is realized; and because the content of the carbon nano tube is low, a network structure is formed in the heating circuit 130, a new conductive channel is formed, the conductive performance and transparency of the heating circuit 130 are also effectively improved, and the heating circuit 130 obtained by curing has high transparency and heating stability.

In an alternative specific example, the transparent conductive material is selected from at least one of poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid, polyacetylene, polyaniline, polypyrrole, polythioether and polyparaphenylene. Of course, in other embodiments, the transparent conductive material is not limited to the above, and may be other transparent and conductive substances.

The dispersant plays a role of dispersing in the above heat-generating composition, so that the carbon nanotubes and the transparent conductive material are uniformly dispersed in the prepared conductive heat-generating paste 300. Optionally, the dispersant is selected from at least one of polyvinylpyrrolidone, carboxymethyl cellulose, ethyl cellulose, and nanocellulose. Of course, the dispersant is not limited to the above, and may be dispersed without affecting the heat generation efficiency and light transmittance of the transparent heat generating layer produced using the above heat generating composition.

Further, the mass ratio of the carbon nano tube to the transparent conductive material to the dispersant is (5-10): (10-15): (1-5). The carbon nanotubes are easy to agglomerate, if the carbon nanotubes cannot be sufficiently dispersed, the contact area of the carbon nanotubes and the transparent conductive material is limited, so that the final contact resistance is large, the carbon nanotubes are agglomerated together, the transparency is reduced, the heat is not uniform, and the final conductive heating capacity is low. The mass ratio of the carbon nano tube to the transparent conductive material to the dispersing agent is set according to the above, so that the carbon nano tube and the transparent conductive material are uniformly dispersed in the system respectively, and the electric charge is favorably transported between the carbon nano tube and the transparent conductive material, so that the light transmittance and the heating capacity of the conductive heating slurry 300 can be ensured when the conductive heating slurry is used, and the rapid heating can be realized only by using lower heating power while the high definition of the conductive heating slurry is maintained. Meanwhile, the content of the carbon nanotubes is moderate, and on the premise of complete dispersion, the conductive heating slurry 300 is favorable for flowing and forming, so that the transparent heating layer cannot be formed due to over-dilution, and the conductive heating slurry 300 is difficult to fill the grooves due to over-thickening. Furthermore, the mass ratio of the carbon nano tube to the transparent conductive material to the dispersant is (5-10): (12-15): (1-5).

In some embodiments, the heat-generating composition further includes an organic solvent. The organic solvent is used to prepare the heat-generating composition into a slurry. Optionally, the organic solvent is at least one of ethylene glycol, butyl glycol ether, and propylene glycol methyl ether. The mass ratio of the carbon nano tube to the transparent conductive material, the dispersant and the organic solvent is (2.5-10): (2.5-15): (1-5): (70-96). In an optional specific example, the heat-generating composition is composed of carbon nanotubes, a transparent conductive material, a dispersant and an organic solvent, wherein the mass ratio of the carbon nanotubes to the transparent conductive material, the dispersant and the organic solvent is (5.5-10): (2.5-15): (1-5): (70-96), the diameter of the carbon nano tube is 6-10 nm. Further, the mass ratio of the carbon nanotubes to the transparent conductive material, the dispersant and the organic solvent is (5.5-10): (12-15): (1-5): (80-90).

The heating composition is used in the form of the conductive heating paste 300, so that when the heating composition contains an organic solvent and each component is packaged separately, each component of the heating composition is directly mixed to prepare the conductive heating paste 300 for use, and the use is convenient; or when the heat-generating composition is packaged in the form of a mixture, the components of the heat-generating composition are mixed and can be directly used, so that the convenience is improved. Of course, when the heat-generating composition does not include an organic solvent, the preparation of the conductive heat-generating paste 300 may be achieved by additionally adding an organic solvent in proportion at the time of use.

The conductive heating paste 300 prepared from the heating composition has the advantages that the carbon nano tube, the transparent conductive material and the dispersing agent are matched, so that the heating circuit 130 is high in heating efficiency and high in light transmittance, the transparent heating composite material 10 is not easy to fog, and is good in light transmittance, high in safety and low in energy consumption.

Optionally, the thickness of the heating circuit 130 is 10 μm to 20 μm; the width of the heating circuit 130 is 2mm to 10 mm. Further, the thickness of the heating circuit 130 is 15 μm to 20 μm; the width of the heating circuit 130 is 4mm to 8 mm. The thickness of the heating circuit 130 is set as above, so that the transparent heating composite material 10 can ensure excellent transparency and heating capability without increasing the thickness of the heating circuit 130 to improve the heating capability, and the heating circuit is not easy to deform in subsequent processing; the width of the heat-generating circuit 130 is set as described above so that the transparent heat-generating composite material 10 can further improve transparency. The region where the heat generating circuit 130 is located may be a part of the transparent heat generating composite material 10. For example, the plurality of heating circuits 130 are disposed on the first transparent substrate 110 at intervals, and the plurality of heating circuits 130 are electrically connected through the transparent conductive circuit, so that the transparent heating composite material 10 has a defogging/frosting function through the cooperation of the plurality of heating circuits 130. Alternatively, only a partial region of the entire transparent heat generating composite material 10 needs defogging/frosting, and in this case, the heat generating circuit 130 is disposed only in the region. Of course, the heating circuit 130 may be disposed on the whole transparent heating composite material 10 according to actual requirements.

In the illustrated embodiment, the transparent heat-generating composite material 10 further includes a bonding layer 140. The adhesive layer 140 is located between the first transparent substrate 110 and the second transparent substrate 120, and the adhesive layer 140 is used to fix the first transparent substrate 110 and the second transparent substrate 120. Optionally, the thickness of the adhesive layer 140 is 0.4mm to 2.4 mm. The material of the adhesive layer 140 is at least one selected from the group consisting of polyvinyl butyral (PVB) and Ethylene Vinyl Acetate (EVA). It is understood that in some embodiments, the adhesive layer 140 may be omitted. For example, when the first transparent base 110 and the second transparent base 120 are both made of transparent resin, the first transparent base 110 and the second transparent base 120 may be fixed integrally by hot press molding. Of course, when the material of the first transparent substrate 110 and the second transparent substrate 120 is a transparent material with poor thermal plasticity such as glass, the first transparent substrate 110 and the second transparent substrate 120 may be fixed by other fixing structures. Note that, the thickness of the bonding layer 140 herein refers to a distance between the first transparent substrate 110 and the second transparent substrate 120.

The heating circuit 130 may be completely accommodated in the groove, or may be partially accommodated in the groove. When the heating circuit 130 is completely accommodated in the groove and the first transparent substrate 110 and the second transparent substrate 120 are made of a material with good thermoplasticity, the first transparent substrate 110 and the second transparent substrate 120 can be fixed by a hot pressing method; when the heat generating circuit 130 is partially received in the groove and the first transparent substrate 110 and the second transparent substrate 120 are not materials with good thermoplasticity, an adhesive layer 140 may be disposed between the first transparent substrate 110 and the second transparent substrate 120 or the first transparent substrate 110 and the second transparent substrate 120 may be fixed in other manners.

In some embodiments, the transparent heat-generating composite material 10 further includes a conductive member 150 for connecting to a power source, wherein the conductive member 150 is electrically connected to the heat-generating circuit 130. Alternatively, conductive member 150 is made of conductive paste containing a conductive material. In one specific example, the conductive paste is a conductive silver paste. Of course, conductive member 150 may also be a wire; such as copper wire, silver wire, etc. Further, the diameter of the metal wire is 0.2mm to 0.7 mm. Alternatively, the conductive member 150 includes two conductive units spaced apart from each other in a line shape, and one end of each of the two conductive units is connected to the heat generating circuit 130, and the other end of each of the two conductive units is electrically connected to a power supply to form a loop. The two conductive units may be located on the same side of the heating circuit 130, or may be located on two opposite sides of the heating circuit 130. It is understood that in some embodiments, conductors 150 may be omitted. At this time, the conductive member 150 is externally connected when in use.

The heating circuit 130 of the transparent heating composite material 10 is located in the groove of the first transparent substrate 110, so that the transparent heating composite material 10 can be thinner, and the heating circuit 130 is made of the conductive heating slurry 300, compared with an indium tin oxide film as a heating layer, the heating circuit 130 can achieve a better heating effect with fewer materials, and has better heating efficiency, and because of the material of the heating circuit 130, the light transmittance is better and lighter; in addition, the heating circuit 130 of the transparent heating composite material 10 can be prepared by coating and baking, and is simple and easy to operate.

In particular to application of the transparent heating composite material in preparing automobile windshields. It is understood that the application of the transparent heating composite material is not limited to the automobile field, and can also be applied to the fields with certain requirements on fog prevention and light transmittance, such as the aerospace field.

The invention further provides an automobile windshield, which is a curved glass and comprises a first transparent substrate, a second transparent substrate and a heating circuit, wherein grooves for accommodating the heating circuit are distributed on the first transparent substrate, and the heating circuit is made of the conductive heating slurry made of the heating composition in any one of the embodiments.

The heating circuit of the automobile windshield is positioned in the groove of the first transparent substrate and is made of the conductive heating slurry made of the heating composition, so that the automobile windshield is lighter and thinner, is not easy to fog, has high light transmittance, high safety and low energy consumption, and has a good application prospect.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The following detailed description is given with reference to specific examples. The following examples are not specifically described, and other components except inevitable impurities are not included. Reagents and instruments used in the examples are all conventional in the art and are not specifically described. The experimental procedures, in which specific conditions are not indicated in the examples, were carried out according to conventional conditions, such as those described in the literature, in books, or as recommended by the manufacturer. In the following examples and comparative examples, unless otherwise specified, the transparent conductive organic material was poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid (PEDOT/PSS), the dispersant was nanocellulose, and the organic solvent was ethylene glycol.

Example 1

The structure of the transparent heating composite material of this embodiment is as shown in fig. 1, and is composed of a first transparent substrate, a bonding layer, a heating circuit and a second transparent substrate, wherein the first transparent substrate and the second transparent substrate are both glass substrates, the material of the bonding layer is PVB, the heating circuit is in a pattern of a shape like a Chinese character 'ji' (as in fig. 3) and is embedded in a groove of the first transparent substrate, the conductive heating slurry for preparing the heating circuit is composed of carbon nanotubes, transparent conductive organic substances, a dispersant and an organic solvent, wherein the diameter of the carbon nanotubes is 6nm, and the mass ratio of the carbon nanotubes, the transparent conductive organic substances, the dispersant and the organic solvent is 5.5: 12: 4: 78.5; the thickness of the first transparent substrate was 5mm, the thickness of the heating circuit was 10 μm, the thickness of the adhesive layer was 0.4mm, and the thickness of the second transparent substrate was 5 mm.

The preparation method of the transparent heat-generating composite material of the embodiment includes, but is not limited to, the following steps:

(1) preparing conductive heating slurry: mixing the carbon nano tube, the transparent conductive organic matter, the dispersing agent and the organic solvent, and mechanically stirring and uniformly dispersing to prepare the conductive heating slurry. Wherein the diameter of the carbon nano tube is 6nm, and the mass ratio of the carbon nano tube, the transparent conductive organic matter, the dispersing agent and the organic solvent is 5.5: 12: 4: 78.5.

(2) and etching a 'n' -shaped groove with the width of 6mm, the interval of 30mm and the depth of 10 mu m on the surface of the first transparent substrate on which the polytetrafluoroethylene film mold is placed by adopting a laser engraving mode, and polishing the surface of the first transparent substrate and the groove wall of the groove smoothly by using a polishing tool.

(3) And (2) coating the conductive heating slurry prepared in the step (1) on a first transparent base material provided with a polytetrafluoroethylene die matched with the groove through a coating machine, so that the conductive heating slurry is filled into the groove, then placing the groove into an oven to be baked for 40min at 50 ℃, and forming a heating circuit after the solvent in the slurry is completely volatilized.

(3) After the mold is removed, PVB with the thickness of 0.4mm is paved and pasted on the heating circuit, a second transparent substrate is placed on the PVB, a sandwich structure with the heating circuit positioned between the first transparent substrate and the second transparent substrate is prepared, then, the sandwich structure is molded through an autoclave molding process, and the transparent heating composite material is prepared, wherein in the autoclave molding process, the temperature is 80 ℃, and the pressure is 0.8 MPa.

Testing

(1) The light transmittance of the transparent heat-generating composite material of example 1 was measured using an LS116 glass light transmittance tester. The test result showed that the transparent heat emitting composite of example 1 had a light transmittance of 85%.

(2) And (3) heating test: the transparent heat-generating composite material of example 1 was applied with a direct current voltage of 5V, and was kept at room temperature before application, and the temperature of the center point of the transparent heat-generating composite material was 25 ℃. And after electrifying for 5 minutes, testing the temperature of the central point of the outer surface of the transparent heating composite material. The result showed that the central temperature of the transparent heat-generating composite material of example 1 was 47.5 ℃.

(2) And (3) defrosting test: the transparent exothermic composite material of example 1 was placed in a low-temperature test chamber, frozen at-18 ℃ for 5 hours or more, sprayed with pure water for 30 minutes at a water spray rate of 5mL/cm²And then, introducing direct current for 20min, and observing the defrosting effect. The result showed that the defrosting area of the transparent heat generating composite material of example 1 was 89%.

Example 2

The structure and the production method of the transparent heat-generating composite material of the present embodiment are substantially the same as those of embodiment 1, except that the thickness of the heat-generating circuit of the transparent heat-generating composite material of the present embodiment is different from that of embodiment 1, and the thickness of the heat-generating circuit of the present embodiment is 15 μm.

The transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 82%, the temperature of the central point after 5min of electrification is 49 ℃, and the defrosting area is 90%.

Example 3

The structure and the production method of the transparent heat-generating composite material of the present embodiment are substantially the same as those of embodiment 1, except that the thickness of the heat-generating circuit of the transparent heat-generating composite material of the present embodiment is different from that of embodiment 1, and the thickness of the heat-generating circuit of the present embodiment is 20 m.

The transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 78%, the temperature of the central point after 5min of electrification is 53 ℃, and the defrosting area is 95%.

Example 4

The structure and the preparation method of the transparent heat-generating composite material of the present embodiment are substantially the same as those of embodiment 2, except that the conductive heat-generating paste for preparing the heat-generating circuit of the transparent heat-generating composite material of the present embodiment is different from embodiment 2, and the conductive heat-generating paste of the present embodiment is composed of carbon nanotubes, a transparent conductive organic substance, a dispersant and an organic solvent, wherein the diameter of the carbon nanotubes is 6nm, and the mass ratio of the carbon nanotubes, the transparent conductive organic substance, the dispersant and the organic solvent is 2.5: 2.5: 1: 94.

the transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 86%, the temperature of the central point after 5min of electrification is 46 ℃, and the defrosting area is 86%.

Example 5

The structure and the preparation method of the transparent conductive heating composite material of the present embodiment are substantially the same as those of embodiment 2, except that the composition of the conductive heating slurry for preparing the heating circuit of the transparent conductive heating composite material of the present embodiment is different from that of embodiment 2, and the conductive heating slurry of the present embodiment is composed of carbon nanotubes, a transparent conductive organic substance, a dispersant and an organic solvent, wherein the diameter of the carbon nanotubes is 6nm, and the mass ratio of the carbon nanotubes, the transparent conductive organic substance, the dispersant and the organic solvent is 10: 15: 5: 70.

the transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 78%, the temperature of the central point after 5min of electrification is 54 ℃, and the defrosting area is 96%.

Example 6

The structure and the manufacturing method of the transparent conductive heat-generating composite material of this example are substantially the same as those of example 2, except that in this example, the aspect ratio of the carbon nanotube is 300.

The transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heat-generating composite material of the embodiment is 72%, the center point temperature after 5min of electrification is 43.8 ℃, and the defrosting area is 83%.

Example 7

The structure and the manufacturing method of the transparent conductive heat-generating composite material of this example are substantially the same as those of example 2, except that in this example, the aspect ratio of the carbon nanotube is 8000.

The transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 70%, the temperature of the central point after 5min of electrification is 42.6 ℃, and the defrosting area is 81%.

Example 8

The structure and the preparation method of the transparent conductive heating composite material of the present embodiment are substantially the same as those of embodiment 2, except that the composition of the conductive heating slurry for preparing the heating circuit of the transparent conductive heating composite material of the present embodiment is different from that of embodiment 2, and the conductive heating slurry of the present embodiment is composed of carbon nanotubes, a transparent conductive organic substance, a dispersant and an organic solvent, wherein the diameter of the carbon nanotubes is 6nm, and the mass ratio of the carbon nanotubes, the transparent conductive organic substance, the dispersant and the organic solvent is 1: 12: 4: 83.

the transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 84%, the temperature of the center point after 5min of electrification is 30.4 ℃, and the defrosting area is 60%.

Example 9

The structure and the preparation method of the transparent conductive heating composite material of the present embodiment are substantially the same as those of embodiment 2, except that the composition of the conductive heating slurry for preparing the heating circuit of the transparent conductive heating composite material of the present embodiment is different from that of embodiment 2, and the conductive heating slurry of the present embodiment is composed of carbon nanotubes, a transparent conductive organic substance, a dispersant and an organic solvent, wherein the diameter of the carbon nanotubes is 6nm, and the mass ratio of the carbon nanotubes, the transparent conductive organic substance, the dispersant and the organic solvent is 15: 15: 5: 65.

the transparent heat emitting composite material of the present example was subjected to the light transmittance, the center temperature and the defrosting effect test with reference to the method of example 1. The test result shows that the light transmittance of the transparent heating composite material of the embodiment is 42%, the temperature of the central point after 5min of electrification is 55 ℃, and the defrosting area is 97%.

In summary, the light transmittance of the transparent heat-generating composite materials of examples 1 to 7 is 70% or more, which is higher than the standard that the visible light transmittance specified by the national GB9656-2016 safety standard should be 70% or more, and the defogging/frosting effect is good.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The preparation method of the transparent heating composite material is characterized by comprising the following steps:

preparing conductive heating slurry;

filling the conductive heating slurry into the groove;

2. The method for preparing a transparent exothermic composite according to claim 1, wherein the step of forming the grooves having the predetermined pattern on the first transparent substrate comprises the following operations:

3. The method for preparing a transparent exothermic composite according to claim 2, wherein the step of filling the conductive exothermic paste into the groove comprises the operations of:

4. The method for preparing a transparent exothermic composite according to claim 2, further comprising a step of removing the release film after the step of drying the first transparent substrate filled with the conductive exothermic paste.

5. The method for preparing a transparent exothermic composite according to claim 1, wherein the depth of the groove is formed to be 10 to 20 μm; and/or the width of the groove is 2 mm-10 mm.

6. The preparation method of the transparent heating composite material as claimed in any one of claims 1 to 5, wherein the conductive heating paste is a carbon nanotube conductive heating paste, and the preparation of the conductive heating paste comprises the following steps:

7. The preparation method of the transparent heating composite material as claimed in claim 6, wherein the length-diameter ratio of the carbon nanotubes is 1000-5000; and/or the presence of a catalyst in the reaction mixture,

8. The method for preparing a transparent exothermic composite according to claim 6, wherein the mass ratio of the carbon nanotubes to the transparent conductive material, the dispersant and the organic solvent is (2.5 to 10): (2.5-15): (1-5): (70-96).

9. The method for producing a transparent heat-generating composite material according to claim 1, wherein the material of the first transparent substrate and the material of the second transparent substrate are each independently selected from one of glass and transparent resin.

10. The method for producing a transparent heat-generating composite material according to claim 1, wherein the step of bonding the first transparent substrate and the second transparent substrate to each other comprises:

11. The method for producing a transparent heat-generating composite material according to claim 10, wherein the material of the adhesive layer is at least one selected from the group consisting of polyvinyl butyral and ethylene-vinyl acetate copolymer, and the thickness of the adhesive layer is 0.4mm to 2.4 mm.

12. The method for preparing a transparent heat-generating composite material according to claim 1, further comprising a step of providing a conductive member electrically connected to the heat-generating circuit before the first transparent base material and the second transparent base material are bonded to each other.

13. A transparent heat-generating composite material characterized by being produced by the method for producing a transparent heat-generating composite material according to any one of claims 1 to 12.

14. An automobile windshield, characterized by being made of the transparent exothermic composite material according to claim 13.