KR20190062152A - Heating glass for vehicle and method for preparing the same - Google Patents

Abstract

According to one embodiment of the present application, heating glass for a vehicle comprises: thin inner glass having a thickness of 0.3-1 mm; a conductive layer provided on the thin inner glass, and provided to be in direct contact with the thin inner glass; a bonding film provided on the conductive layer; and outer glass provided on the bonding film. Therefore, the heating glass for a vehicle can implement a heat generating layer on thin inner glass, and is operated for the purpose of dehumidifying rather than defrosting.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heat-

This application claims the benefit of Korean Patent Application No. 10-2017-0160356, filed on November 28, 2017, to the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-generating glass for an automobile and a manufacturing method thereof.

Fogging occurs when the temperature of the inside surface of the car falls below the dew point because the outside temperature of the car is lower than the inside temperature. Heat glass may be used to solve this problem. The front heating glass of an automobile is manufactured by depositing or applying a conductive material on a glass surface, or by depositing or applying a conductive material inside a bonding film and then performing bonding. The concept of increasing the temperature of the glass surface by applying electricity to both ends of the conductive material applied to the heating glass is used to generate heat.

In particular, since the windshield of an automobile must have no element that interferes with the driver ' s visual field, there are two methods adopted to give a heat generating function with excellent optical performance.

The first method is to form a transparent conductive thin film on the entire surface of the glass. As a method for forming the transparent conductive thin film, there is a method of using a transparent conductive oxide film such as ITO or forming a thin metal layer, and then using a transparent insulating film above and below the metal layer to increase the transparency. Although this method has the advantage of forming an optically excellent conductive film, it has a disadvantage in that an appropriate calorific value can not be realized at a low voltage due to a relatively high resistance value.

The second method uses a metal pattern or a wire, but maximizes the area without the metal pattern or the wire to increase the transmittance. A typical product using this method is a heating glass made by inserting a tungsten wire into a PVB film used for automobile windshield joining. In this method, the diameter of the tungsten wire used is 18 micrometers or more, which is a level of conductivity capable of ensuring a sufficient calorific value at a low voltage. However, due to the relatively thick tungsten wire, There are disadvantages. In order to overcome this, a metal pattern may be formed on the PET film through a printing process, or a metal layer may be attached on the PET film, and then a metal pattern may be formed through a photolithography process. After the PET film having the metal pattern formed thereon is inserted between two sheets of PVB film, a heat-generating product having a heat-generating function can be made through a glass bonding process. However, by inserting the PET film between the two PVB films, the difference in refractive index between the PET film and the PVB film can cause distortion of objects seen through the automobile glass, and the external light source is diffracted by the metal pattern, It is disadvantageous to interfere with the field of view.

Korean Patent Publication No. 10-2013-0101680

In this specification, a heat-generating glass for an automobile and a manufacturing method thereof are described.

In one embodiment of the present application,

A thin inner glass having a thickness of 0.3 mm to 1 mm;

A conductive layer provided on the thin inner glass, the conductive layer being provided in direct contact with the thin inner glass;

A bonding film provided on the conductive layer; And

The outer glass provided on the bonding film

And a heat-resistant glass for automobile.

Further, another embodiment of the present application,

Preparing a curved outer glass;

Forming a conductive layer on the thin inner glass having a thickness of 0.3 mm to 1 mm and in a flat plate shape so as to be in direct contact with the thin inner glass; And

Bonding the curved outer glass and the inner glass provided with the conductive layer to each other via a bonding film

The present invention also provides a method for manufacturing an automotive heat-generating glass.

The heat generating glass for an automobile according to one embodiment of the present application can implement a heat generating layer on a thin inner glass and is operated for the purpose of dehumidifying rather than defrosting. Accordingly, the heat-generating glass for an automobile according to an embodiment of the present application is characterized in that the thermal energy generated in the heat-generating layer has a thermal conductivity higher than that of the bonding film but thinner than the bonding film, And since the loss of heat energy is low due to the low thermal conductivity of the bonding film, the function can be realized with a lower output than the conventional front heating glass.

In addition, since a heat generating layer is directly formed on the glass surface, various bonding films can be applied, and additional functions such as a head-up display (HUD) can be provided at the same time as a heat generating function.

1 and 2 are views schematically showing a heat-generating glass for a vehicle according to an embodiment of the present application.
FIGS. 3 and 4 schematically show a conventional heating glass for a vehicle, respectively.

In the following, the present application will be described in more detail.

In the case of the conventional front heating glass for automobiles, a metal wire for heat generation is embedded in a bonding film or a metal oxide is coated on a glass surface. However, in the case of metallic wires, heat efficiency is lowered due to the low thermal conductivity of the bonding film. In the case of coating metal oxide on the glass surface, since the shape of the front glass of the automobile is curved, it is difficult to obtain a uniform conductive film. have. FIG. 3 schematically shows a case in which a metal wire for heat generation is embedded in the bonding film as the conventional heating glass for an automobile. 4 is a schematic view of a conventional heat-generating glass for a vehicle, in which a metal oxide layer for heat generation is embedded in a bonding film. 3 and 4, the upper drawing is a plan view of a heat-generating glass for an automobile, and the lower drawing is a side view of a heat-generating glass for an automobile.

Also, in the case of defrosting function through front heat generation, it is used in some polar regions, so frequency of use is low, and fault frequency of disconnection due to high heat temperature is high, which makes it difficult to expand the market size.

On the other hand, when moisture is applied to the windshield, there is a high risk of accidents due to obstructing the driver's vision. When the air conditioning function is operated to remove moisture, the humidity inside the vehicle is kept lower than necessary, Even when the internal temperature of the vehicle is low, when the condenser is operated for operating the air conditioner, the load of the engine is increased, which is a main cause of lowering the fuel efficiency.

Accordingly, in the present application, it is desired to provide a heat-generating glass for an automobile which can be operated for dehumidification instead of defrosting, and which can realize a function with a lower output than a conventional front heating glass.

According to one embodiment of the present application, a heat-generating glass for a vehicle includes: a thin inner glass having a thickness of 0.3 mm to 1 mm; A conductive layer provided on the thin inner glass, the conductive layer being provided in direct contact with the thin inner glass; A bonding film provided on the conductive layer; And an outer glass provided on the bonding film.

In the present application, the inner glass means glass provided inside the automobile, and the outer glass means glass provided outside the automobile.

In the present application, the thin inner glass has a thickness of 0.3 mm to 1 mm, preferably 0.4 mm to 0.7 mm. The thin inner glass may be flat glass, and the flat glass may be cold bending. As described in a manufacturing method of an automotive heat-generating glass to be described later, since the inner glass is thin and has a thin thickness, it has flexibility similar to that of a film. Accordingly, the outer glass, cold bending method.

In the present application, the conductive layer is provided on the thin inner glass, and the conductive layer may serve as a heating layer in an automobile heating glass. In particular, the conductive layer may be in direct contact with the thin inner glass.

The conductive layer may be provided on the entire surface of the thin inner glass, and may be provided in a planar or linear pattern. At this time, the conductive layer may be provided in contact with the bonding film. In addition, the linear pattern may include a straight line, a curve, a zigzag, a random pattern, or a combination thereof.

The conductive layer may be formed of a transparent conductive material. Examples of transparent conductive materials include ITO (indium tin oxide) and ZnO-based transparent conductive oxides. The transparent conductive oxide may be formed on the thin inner glass by sputtering, a sol-gel method, or a vapor deposition method. The thickness of the transparent conductive oxide is preferably 10 nm to 1,000 nm. Further, an opaque conductive material may be formed by coating and coating with a thickness of 1 nm to 100 nm. Examples of the opaque conductive material include Ag, Au, Cu, Al, metal nanowires, and carbon nanotubes.

As the material of the conductive layer, a metal having excellent thermal conductivity may be used. Also, the resistivity value of the conductive layer material may have a value of 1 micro Ohm cm to 200 micro Ohm cm. At this time, the conductive layer may be provided in the form of a conductive metal line pattern. As a concrete example of the conductive metal wire material, copper, silver, platinum, molybdenum, nickel, chromium, titanium, alloys thereof and the like can be used, and silver is most preferable. The conductive metal wire material may be used in the form of particles. In the present application, copper particles coated with silver may also be used as the conductive metal wire material.

In the present application, when the conductive metal wire is manufactured using a printing process using paste, the paste may further include an organic binder in addition to the conductive metal wire material described above so as to facilitate the printing process. The organic binder may have a property of being volatilized during the firing process. Examples of the organic binder include a polyacrylic resin, a polyurethane resin, a polyester resin, a polyolefin resin, a polycarbonate resin, a cellulose resin, a polyimide resin, a polyethylene naphthalate resin and a modified epoxy. The present invention is not limited thereto.

In order to improve the adhesion of the paste to the thin inner glass, the paste may further include a glass frit. The glass frit can be selected from commercial products, but it is preferable to use an environmentally friendly glass frit without lead component. At this time, it is preferable that the size of the glass frit to be used is not more than 2 mu m in average diameter and not more than 50 mu m in maximum diameter.

If necessary, an additional solvent may be added to the paste. Examples of the solvent include butyl carbitol acetate, carbitol acetate, cyclohexanone, cellosolve acetate, and terpineol. According to these examples, The scope of the present application is not limited.

In the present application, when a paste containing a conductive metal wire material, an organic binder, a glass frit and a solvent is used, the weight ratio of each component is 50 wt% to 90 wt% of the conductive metal wire material, 1 wt% to 20 wt% 0.1 to 10% by weight of glass frit, and 1 to 20% by weight of a solvent.

In the present application, in the case of using the paste described above, a metal wire having conductivity is formed when the paste is printed and then subjected to a firing process. In this case, the firing temperature is not particularly limited, but may be 500 캜 to 800 캜, and may be 600 캜 to 700 캜.

The line width of the conductive metal wire may be 100 탆 or less, 30 탆 or less, 25 탆 or less, 10 탆 or less, further preferably 7 탆 or less, and 5 탆 or less. The line width of the conductive metal wire may be 0.1 탆 or more and 0.2 탆 or more. The line spacing of the conductive metal lines may be less than or equal to 30 mm, may be between 0.1 and 1 mm, may be between 0.2 and 600 탆, and may be less than or equal to 250 탆.

The conductivity of the conductive metal wire may be 20 탆 or less, 5 탆 or less, and 2 탆 or less. In the present application, the line width and line height of the heating line can be made uniform by the above-described methods.

In the present application, the uniformity of the conductive metal wire may be within the range of ± 3 micrometers for line width, and within ± 1 micrometer range for sentence.

In the present application, the outer glass may be a curved glass. The thickness of the outer glass may be greater than or equal to 1 mm and less than or equal to 3 mm, but is not limited thereto.

The outer glass may be bonded to the inner glass provided with the conductive layer via a bonding film.

The bonding film is not particularly limited, and a bonding film known in the art can be applied. More specifically, the bonding film may include, but is not limited to, polyvinylbutyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU), and polyolefin (PO).

The thickness of the bonding film may be 0.3 mm to 1 mm, but is not limited thereto.

In the present application, the visible light transmittance of the automotive front heat-generating glass may be 70% or more and 80% or more, but is not limited thereto.

According to another embodiment of the present application, the apparatus further comprises a pair of opposed bus bars for applying electricity to the conductive layer.

According to another embodiment of the present application, a black pattern may be provided to cover the bus bar. For example, the black pattern can be printed using a paste of black color. At this time, the printing method is suitable for screen printing, and the thickness can be set to 10 탆 to 100 탆. The conductive layer and the bus bar may be formed before or after forming the black pattern, respectively.

The heat generating glass for an automobile according to the present application may be connected to a power source for generating heat, and the amount of heat generated is preferably 30 W to 500 W, preferably 50 W to 300 W per m ² .

FIG. 1 schematically shows a heat-generating glass for an automobile according to an embodiment of the present application. As shown in FIGS. 1 and 2, a heat-generating glass for an automobile according to an embodiment of the present application comprises: a thin inner glass 10 having a thickness of 0.3 mm to 1 mm; A conductive layer (20) provided on the thin inner glass (10); A bonding film (30) provided on the conductive layer (20); And an outer glass (40) provided on the bonding film (30). Particularly, FIG. 1 schematically shows a case where the conductive layer 20 is provided in a linear pattern. The case where the conductive layer 20 is provided on a flat surface on the thin inner glass sheet 10 is schematically shown in Fig. 1 and 2, the upper drawing is a plan view of a heat-generating glass for an automobile, and the lower drawing is a side view of a heat-generating glass for an automobile.

According to another aspect of the present invention, there is provided a method of manufacturing an automotive heat-resistant glass, comprising: preparing a curved outer glass; Forming a conductive layer on the thin inner glass having a thickness of 0.3 mm to 1 mm and a flat plate shape; And bonding the curved outer glass and the inner glass having the conductive layer to each other via a bonding film.

In the method for manufacturing the automotive heat-generating glass, the contents of the thin inner glass, the conductive layer, the bonding film and the outer glass are the same as those described above, and a detailed description thereof will be omitted.

In the present application, the step of joining the outer glass and the inner glass may be performed in a cold bending manner. Since the inner glass is thin and thin, it has flexibility similar to that of the film, and thus can be bonded to the outer glass which has been previously curved without forming the curved surface in a cold bending manner.

The joining step may bond the inner glass to a concave surface of the curved outer glass using a bonding film or an adhesive. For example, after locating the bonding film between one side of the plate-like inner glass and the concave side of the curved outer glass, the elastically deformed inner glass is bonded to the one side of the curved outer glass through the bonding film Respectively. Further, by applying an adhesive on one surface of the plate-like inner glass and / or on the concave surface of the curved outer glass, the elastically deformed inner glass is bonded to the concave surface of the curved outer glass through the adhesive .

The bonding step may be carried out at a temperature of 80 ° C to 140 ° C. That is, the elastically deformed inner glass and the curved outer glass can be bonded at a temperature of 80 캜 to 140 캜.

Further, a process of high temperature and high pressure treatment in an autoclave can be performed to complete the joining of the elastically deformed inner glass and the curved outer glass.

The curved outer glass and the elastically deformed inner glass may have substantially the same radius of curvature. This means that even if the radius of curvature of the curved outer glass and that of the elastically deformed inner glass are somewhat different, the curved outer glass and the elastically deformed inner glass may have the same radius of curvature after they are joined have.

Since the resiliently deformed inner glass is bonded to one concave surface of the curved outer glass, it is preferable that the inner glass plate before being elastically deformed to a curved surface has a smaller dimension than the outer glass plate before being curved . Further, it may be preferable to join the elastically deformed inner glass so that the edges are formed and matched together at the same position as the curved outer glass.

The heat generating glass for an automobile according to one embodiment of the present application can implement a heat generating layer on a thin inner glass and is operated for the purpose of dehumidifying rather than defrosting. Accordingly, the heat generating glass for an automobile according to one embodiment of the present application can realize a function with a lower output than a conventional front heat generating glass.

Hereinafter, an embodiment of the present invention will be described by way of example. However, it is not intended that the scope of the embodiments be limited by the following embodiments.

< Example >

< Example  1>

AgNW, a conductive material, was uniformly applied to the surface of a thin plate glass having a thickness of 0.5 mm using a bar coater and dried at 135 ° C for 3 minutes. Thereafter, a 0.78 mm thick bonding film was placed between the 2.1 mm soda lime glass and the laminated glass, and the laminate was pressure-bonded under a pressure of 300 Torr at 80 캜. The laminated glass and soda lime glass thus pressed were treated in an autoclave at 130 캜 and 11.76 bar to prepare a bonded glass.

< Example  2>

AgNW, a conductive material, was uniformly applied to the surface of a thin plate glass having a thickness of 0.4 mm using a bar coater and dried at 135 ° C for 3 minutes. Thereafter, a 0.78 mm thick bonding film was placed between the 2.1 mm soda lime glass and the laminated glass, and the laminate was pressure-bonded under a pressure of 300 Torr at 80 캜. The laminated glass and soda lime glass thus pressed were treated in an autoclave at 130 캜 and 11.76 bar to prepare a bonded glass.

< Comparative Example  1>

AgNW, a conductive material, was applied uniformly on a 0.05 mm thick PET surface using a bar coater and dried at 135 ° C for 3 minutes. Thereafter, PET coated with a conductive material was sandwiched between two sheets of 0.38 mm thick bonding films and put between two 2.1 mm soda lime glass substrates to prepare a bonded glass in the same manner as in Example 1. [

< Experimental Example > Heat test

The exothermic test for the bonded glass produced in Examples 1 to 2 and Comparative Example 1 was carried out as follows.

The laminated glasses prepared in Examples 1 and 2 and Comparative Example 1 were prepared and the heat generation temperature was measured by applying electricity at an output of 100 W at room temperature. The results are shown in Table 1 below. The temperature of the heating surface was measured at the center of the coated glass.

[Table 1]

As a result of measuring the exothermic temperature, it was confirmed that the exothermic temperature reaching time was about 20% difference between Examples 1 and 2 and Comparative Example 1.

The heat generating glass for an automobile according to one embodiment of the present application can implement a heat generating layer on a thin inner glass and is operated for the purpose of dehumidifying rather than defrosting. Accordingly, the heat-generating glass for an automobile according to an embodiment of the present application is characterized in that the thermal energy generated in the heat-generating layer has a thermal conductivity higher than that of the bonding film but thinner than the bonding film, And since the loss of heat energy is low due to the low thermal conductivity of the bonding film, the function can be realized with a lower output than the conventional front heating glass.

In addition, since a heat generating layer is directly formed on the glass surface, various bonding films can be applied, and additional functions such as a head-up display (HUD) can be provided at the same time as a heat generating function.

10: thin inner glass
20: Conductive layer
30: Laminated film
40: outer glass
50: inner glass

Claims (14)

A thin inner glass having a thickness of 0.3 mm to 1 mm;
A conductive layer provided on the thin inner glass, the conductive layer being provided in direct contact with the thin inner glass;
A bonding film provided on the conductive layer; And
The outer glass provided on the bonding film
Wherein the heating glass is a glass. The heating glass for automobile according to claim 1, wherein the conductive layer is provided in an in-plane or linear pattern on the thin inner glass. The automotive heat-generating glass according to claim 1, wherein the thickness of the thin inner glass is 0.4 mm to 0.7 mm. The heat-generating glass for automobile according to claim 1, wherein the thin inner glass is formed by cold bending a flat glass provided with the conductive layer. The heating glass according to claim 1, wherein the conductive layer comprises at least one of Ag, Au, Cu, Al, metal nanowires, and carbon nanotubes. The heating glass according to claim 1, wherein the bonding film comprises polyvinylbutyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU), or polyolefin (PO). The automotive heat-generating glass according to claim 1, wherein the thickness of the bonding film is 0.3 mm to 1 mm. The automotive heat-generating glass according to claim 1, wherein the outer glass is a curved glass. The automotive heat-generating glass according to claim 1, wherein the thickness of the outer glass is greater than or equal to 1 mm and less than or equal to 3 mm. The automotive heat-generating glass according to claim 1, wherein the automotive heat-generating glass has a visible light transmittance of 70% or more. Preparing a curved outer glass;
Forming a conductive layer on the thin inner glass having a thickness of 0.3 mm to 1 mm and in a flat plate shape so as to be in direct contact with the thin inner glass; And
Bonding the curved outer glass and the inner glass provided with the conductive layer to each other via a bonding film
And heating the glass. 12. The method of claim 11, wherein the step of joining the outer glass and the inner glass is performed in a cold bending manner. 12. The method according to claim 11, wherein the conductive layer is provided in an in-plane or linear pattern on the thin inner-layer glass. 12. The method of claim 11, wherein the conductive layer comprises at least one of Ag, Au, Cu, Al, metal nanowires, and carbon nanotubes.

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