KR102402734B1 - Heating film and method for manufacturing thereof - Google Patents

Abstract

A heating film according to an exemplary embodiment of the present application includes: a first adhesive film; a resin layer provided on the first adhesive film, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; a metal foil pattern provided on the resin layer; and a second adhesive film provided on the metal foil pattern.

Description

Heating film and manufacturing method thereof

The present application relates to a heating film and a method for manufacturing the same.

When there is a difference between the outside temperature and the inside temperature of the vehicle, moisture or frost is generated on the glass of the vehicle. To solve this, a heating glass may be used. Heating glass uses the concept of attaching a heating wire sheet to the glass surface or forming a heating wire directly on the glass surface, and applying electricity to both terminals of the heating wire to generate heat from the heating wire, thereby raising the temperature of the glass surface.

In particular, there are the following methods as a method employed to impart a heat function while having excellent optical performance to the windshield of an automobile.

First, a transparent conductive thin film can be formed on the entire surface of the glass. As a method of forming the transparent conductive thin film, there is a method of increasing transparency by using a transparent conductive oxide film such as ITO or by forming a thin metal layer and then using a transparent insulating film above and below the metal layer. This method has an advantage in that an optically excellent conductive film can be formed, but has a disadvantage in that an appropriate amount of heat cannot be realized at a low voltage due to a relatively high resistance value.

Second, a method of increasing transmittance by using a metal pattern or wire, but maximizing an area without a metal pattern or wire may be used. A representative product using this method is a heating glass made by inserting a tungsten wire into the PVB film used for bonding the windshield of an automobile. In the case of this method, the diameter of the tungsten wire used is 18 μm or more, which can realize a level of conductivity that can secure a sufficient amount of heat at a low voltage, but due to the relatively thick tungsten wire, it is visually visible. There are disadvantages.

Third, a metal pattern may be formed on the PET film through a printing process, or a metal pattern may be formed through a photolithography and etching process after forming a metal layer on the PET film. After inserting the PET film on which the metal pattern is formed between two PVB films, a glass bonding process can be performed to produce a heating product having a heating function. However, as the PET film is inserted between the two PVB sheets, the difference in refractive index between the PET film and the PVB sheet may cause distortion of objects viewed through the automobile glass.

Republic of Korea Patent Publication No. 10-2014-0140741

In the present specification, a heating film and a method for manufacturing the same are described.

An exemplary embodiment of the present application is,

a first adhesive film;

a resin layer provided on the first adhesive film, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49;

a metal foil pattern provided on the resin layer; and

A second adhesive film provided on the metal foil pattern

It provides a heating film comprising a.

In addition, another embodiment of the present application is,

a first resin sheet;

a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49;

a metal foil pattern provided on the resin layer; and

A second adhesive film provided on the metal foil pattern

It provides a heating film comprising a.

In addition, another embodiment of the present application is,

a first resin sheet;

a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; and

Metal foil pattern provided on the resin layer

It provides a heating film comprising a.

In addition, another embodiment of the present application is,

forming a resin layer having a thickness of 3 μm to 50 μm and a refractive index of 1.45 to 1.49 on the metal foil film;

forming a first adhesive film on the resin layer;

forming a metal foil pattern by patterning the metal foil film; and

Forming a second adhesive film on the metal foil pattern

It provides a method for producing a heating film comprising a.

In addition, another embodiment of the present application is,

a first resin sheet; a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; and a heating film including a metal foil pattern provided on the resin layer;

a first glass provided on one side of the heating film; and

A second glass provided on the other side of the heating film

It provides a heating glass for automobiles comprising a.

According to an exemplary embodiment of the present application, it is possible to omit the deposition process by using a metal foil film without forming a metal pattern by an expensive deposition process as in the prior art, thereby reducing the cost of fabric and manufacturing a heating film at low cost can do.

In addition, according to an exemplary embodiment of the present application, since the heatable metal foil pattern is directly supported on the roll-type PVB film rather than the PET film, it is possible to manufacture laminated glass based on the metal foil pattern excluding the PET film, thus It may be advantageous for bonding with glass having a large curvature. In addition, it is possible to prevent distortion of the field of view due to a difference in refractive index between the PET film and PVB, which is a conventional problem.

In addition, since the heating glass for automobiles according to an exemplary embodiment of the present application uses a resin having the same refractive index as an interlayer of laminated glass as an adhesion layer, even if the roughness of the metal foil film is high, glass lamination After the haze is reduced, it is possible to improve the optical characteristics.

1 and 2 are views schematically showing a heating film according to an exemplary embodiment of the present application, respectively.
3 to 5 are views schematically showing a heating glass for a vehicle according to an exemplary embodiment of the present application, respectively.

Hereinafter, the present invention will be described in more detail.

Among the methods employed to impart a heat function while having excellent optical performance to the windshield of a vehicle, in the case of etching after forming a metal layer on PET, when the thickness of the metal becomes thick, plating after deposition of a seed layer It has to be formed by such a method, but has the disadvantage that the price is very high. In addition, most car windshields are at least 1 m and 1.4 m in height and width, respectively. Also, the height and width of many of these cars are 1.2m and 1.5m, respectively, and some large car models have a height of 1.4m or more. In order to secure the driver's field of vision, it is sufficient to heat an area of 1m × 1.2m. However, due to the size of the windshield, it is necessary to prepare, pattern, or etch a fabric having a metal layer having a larger area than necessary. In addition, PET films applicable to special purposes such as automobile windshields are more expensive than general films. Therefore, when PET, which is actually applicable to the windshield of an automobile, is used from the metal patterning process, cost increase and yield decrease may occur.

And, the metal layer in contact with the PET surface is a metal layer formed by a thin film seed layer and sputtering, which has a low surface roughness and sparkles smoothly. Patterns are easily recognized because of their unique reflectivity.

If the metal foil is patterned after bonding PET and adhesive, the unit cost of the fabric can be lowered. However, in this case, since adhesive strength must be excellent in order to secure etching stability, when the adhesive is completely cured, roughness corresponding to the surface roughness peculiar to the metal foil is generated on the surface of the adhesive, so that the film and laminated glass have haze. has the disadvantage of increasing.

Auto glass manufacturers usually receive products with a heating element embedded on the PVB film rather than separately supplying the heating film and PVB film, and glass manufacturers prefer to manufacture heating glass only by installing PVB and assembling busbars. do. In this case, it is preferable to produce the product in the form of a roll in which the heating element is supported on PVB. In order to be able to produce a product in which a heating element is supported on a PVB film in a roll form, roll lamination must be possible stably for at least 5 minutes or less.

A method of forming a metal foil pattern on an adhesive film and then transferring it to a PVB sheet through a thermal lamination process was also attempted. However, most of the known methods are to transfer a metal foil pattern on an adhesive film to a PVB sheet by long-term pressing under high heat and pressure. For example, it is not easy to produce a product in which a metal foil pattern is supported on PVB in a roll form because it proceeds under conditions such as bonding under vacuum for 15 minutes or more at a temperature of 100° C. or higher in a vacuum bonding machine. In addition, under such conditions of high temperature and high pressure for a long period of time, the inherent surface roughness of the PVB film for automobiles is damaged, and the air trapped inside is difficult to escape in the process of manufacturing laminated glass, so the characteristics of laminated glass are deteriorated.

Accordingly, in the present application, it is an object of the present application to provide a heating film that has excellent heating characteristics at low voltage and is integrated with a laminated film used in a laminated glass process for automobiles. In addition, in the present application, it is intended to provide a heating film in which a metal foil pattern is embedded in PVB, which can be processed into a roll film without a PET film, and a heating glass for automobiles including the same.

A heating film according to an exemplary embodiment of the present application includes: a first adhesive film; a resin layer provided on the first adhesive film, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; a metal foil pattern provided on the resin layer; and a second adhesive film provided on the metal foil pattern.

In an exemplary embodiment of the present application, the first adhesive film includes a first plastic substrate and a first adhesive layer provided on the first plastic substrate, and the first adhesive layer is provided in contact with the resin layer. can

The first plastic substrate is preferably a flexible film such as polyethylene terephthalate (PET), cyclic olefin polymer (COP), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), acetyl celluloid, or the like. The first plastic substrate may be a transparent film having a visible light transmittance of 80% or more, but it is not necessarily transparent. The first plastic substrate is more preferably PET. The thickness of the first plastic substrate may be 50 μm to 125 μm, but is not limited thereto.

The first adhesive layer may include at least one of a silicone-based polymer and an acrylic polymer.

The peeling strength of the first adhesive film may be 15gf/25mm to 300gf/25mm, and 15gf/25mm to 100gf/25mm. In the present application, the peel strength of the first adhesive film may be measured by the ASTM D3330 evaluation method.

When the peel strength of the first adhesive film is less than 15 gf/25 mm, it may be difficult to stably support the metal foil when the subsequent processes such as photolithography, development, and metal etching are performed in a roll-to-roll (R2R) large area. In addition, when the peel strength of the first adhesive film exceeds 300 gf/25 mm, it may be difficult to properly remove the first adhesive film with low tension without damaging other layers of the film.

In an exemplary embodiment of the present application, the resin layer has a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49. The refractive index of the resin layer is more preferably 1.47 to 1.48.

In the present application, the refractive index of the resin layer, etc. is a prism coupler (Prism Coupler; equipment example - Metricon's 2010/M), ellipsometer (　 equipment example - Horriba Scientific's UVISEL), Abbe Refractometer; equipment Example - It can be measured with Kruss' AR4), etc. For example, a refractive index may be calculated by measuring a change in the amount of light reflected from the coating layer using a prism coupler. More specifically, a material for which a refractive index is to be measured is coated on glass or other substrate with a known refractive index by a method such as spin coating to a thickness of several μm, and then the coated sample is brought into contact with a prism. After that, when the laser is incident on the prism, most of it is totally reflected, but when a specific incident angle and conditions are satisfied, an evanescent field is generated at the interface and the light is coupled. When coupling occurs and the angle at which the intensity of light detected by the detector sharply decreases is measured, the prism coupler can automatically calculate the refractive index of the coating layer from the parameters related to the polarization mode of the light and the refractive index of the prism and the substrate.

In general, automobile windshields are manufactured by inserting a bonding film between two sheets of glass and laminating them at high temperature and high pressure. At this time, polyvinyl butyral (PVB), ethyl vinyl acetate (EVA), etc. are mainly used as the bonding film, and the refractive index of these materials is 1.45 to 1.49, and most of them are 1.47 to 1.48. If the refractive index of the resin layer / laminated film is the same or the difference is small after glass lamination, haze can be reduced, so it is preferable to adjust the refractive index of the resin layer to 1.45 to 1.49. If the refractive index of the resin layer is different from that of the bonding film, the light has a high haze due to internal scattering while passing through the glass, which is more severe when the unevenness of the resin layer is large.

In addition, the thickness of the resin layer may be 3㎛ to 50㎛, 7㎛ to 25㎛. When the thickness of the resin layer is less than 3 μm, it is difficult to evenly coat the entire area of the metal foil having large irregularities. When the thickness of the resin layer exceeds 50 μm, the resin layer material is wasted unnecessarily, and it is difficult to stably manufacture a thick resin layer on a relatively thin metal foil compared to the resin layer because solvent drying is difficult. In addition, when the bonding film and glass are laminated on both sides of the heating film after manufacturing the heating film and bonded at a high temperature/high pressure, the metal foil pattern may be deformed, resulting in tension or disconnection.

In addition, the resin layer may include at least one of polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), and an acrylate-based polymer. In particular, the resin layer more preferably includes polyvinyl butyral (PVB).

The glass transition temperature (Tg) of the resin layer may be in a range of 25°C to 80°C, and may be in a range of 25°C to 60°C. When the glass transition temperature of the resin layer is less than 25° C., it is difficult to stably store the prepared heating film at room temperature. In addition, when the glass transition temperature of the resin layer is low, the fluidity becomes greater in a high-temperature process such as a process for manufacturing a heating film or a process for bonding the first resin sheet and glass, so that the metal foil pattern is deformed and stretched or more vulnerable to breakage.

In an exemplary embodiment of the present application, the metal foil pattern is provided on the resin layer. The ten-point average roughness (Rz) of the surface of the metal foil pattern in contact with the resin layer may be 0.7 μm or more, and may be 0.7 μm to 3.0 μm.

When the Rz is less than 0.7 μm, it has a high reflectance characteristic of the metal foil due to low unevenness. Therefore, since it is difficult to lower the reflectance of the heating film and the heating glass manufactured therefrom, there is a disadvantage that the pattern is easily recognized by the eye due to the high reflectance.

A height of the metal foil pattern may be 2 μm to 15 μm, and the metal foil pattern may include an aluminum foil pattern or a copper foil pattern. At this time, the height of the metal foil pattern can be measured with a micrometer or a thickness gauge.

The metal foil pattern may be manufactured from a metal foil including at least one surface of a matt surface having a relatively high ten-point average roughness (Rz). At this time, the mat surface of the metal foil is in contact with the resin layer.

In the present application, the reflectance of the metal foil at a wavelength of 380 nm to 780 nm measured on a mat surface having a relatively high ten-point average roughness (Rz) may be 67% or less, 50% or less, and 30% or less. In addition, the metal foil pattern may include an aluminum foil pattern or a copper foil pattern having an average reflectance of 15% or less at a wavelength of 380 nm to 780 nm.

The reflectance may be measured using equipment such as UV-3600 or Solidspec-3700 manufactured by Shimadzu of Japan.

The metal foil pattern may have a line width of 4 μm to 20 μm, and a sheet resistance of 0.05 ohm/sq to 0.5 ohm/sq. In addition, based on the entire upper area of the resin layer, the ratio of the upper area of the resin layer provided with the metal foil pattern may be 20% or less, 10% or less, 1% to 20%, 1% to It can be 10%. In addition, the total length of the lines of the metal foil pattern included in the area of 25 cm ² may be 2m to 11m.

In an exemplary embodiment of the present application, the second adhesive film includes a second plastic substrate and a second adhesive layer provided on the second plastic substrate, and the second adhesive layer is provided in contact with the metal foil pattern. can

The second plastic substrate is preferably a flexible film such as polyethylene terephthalate (PET), cyclic olefin polymer (COP), polyethylene naphthalate (PEN), polyethersulfone (PES), polycarbonate (PC), acetyl celluloid, or the like. The second plastic substrate may be a transparent film having a visible light transmittance of 80% or more, but it is not necessarily transparent. The second plastic substrate is more preferably PET. The thickness of the second plastic substrate may be 25 μm to 75 μm, but is not limited thereto.

The second adhesive layer may include at least one of a silicone-based polymer and an acrylic polymer.

The peeling strength of the second adhesive film is preferably greater than the peeling strength of the first adhesive film. In the present application, the peel strength of the second adhesive film may be measured by ASTM D3330 evaluation method. In addition, the peel strength of at least one of the first adhesive film and the second adhesive film is changed from 100gf/25mm to 300gf/25mm before UV or heat irradiation to 15gf/25mm to 90gf/25mm after UV or heat irradiation can do.

When the peel strength of the first adhesive film is lowered from 100gf/25mm to 300gf/25mm to 15gf/25mm to 90gf/25mm by UV irradiation, the first adhesive film is provided on the surface of the resin layer under the metal foil and then photolithography , development, metal etching, etc., proceed in a state in which the lower part of the metal film is UV-blocked to stably support the metal foil. By removing the first adhesive film, it is possible to reduce damage to other layers of the film in the first adhesive film removal step.

In addition, when the peel strength of the second adhesive film is lowered from 100gf/25mm to 300gf/25mm to 15gf/25mm to 90gf/25mm by UV irradiation, the UV is blocked until the time when the first adhesive film is removed. While progressing and stably supporting the metal foil, the adhesive force of the second adhesive film is high, so that the first adhesive film can be easily removed, and after the first adhesive film is removed, the adhesive force is lowered by irradiating UV to lower the adhesive force to the second adhesive The film can be easily removed.

In an exemplary embodiment of the present application, a blackening layer pattern may be further included on at least a portion of a surface of the metal foil pattern that is not in contact with the resin layer. The surface of the metal foil pattern not in contact with the resin layer may be an upper surface and a side surface of the metal foil pattern. The blackening layer pattern may include at least one material such as chromium-based, selenium-based, copper sulfide-based, copper oxide-based, copper nitride-based, copper sulfide-based, aluminum oxynitride-based, or copper oxynitride-based material. The blackening layer pattern is formed by wet coating the above-mentioned material on at least a part of the surface that is not in contact with the resin layer of the metal foil pattern, or a material such as aluminum oxynitride series or copper oxynitride series at 30 nm to 70 nm. It can be formed by a sputtering process.

In addition, the heating film according to another exemplary embodiment of the present application includes a first resin sheet; a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; a metal foil pattern provided on the resin layer; and a second adhesive film provided on the metal foil pattern.

In addition, the heating film according to another exemplary embodiment of the present application includes a first resin sheet; a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; and a metal foil pattern provided on the resin layer.

In the heating film including the first resin sheet, the first adhesive film is removed from the heating film including the first adhesive film, and the first resin sheet is formed on the opposite side of the surface on which the metal foil pattern of the resin layer is formed. It can be manufactured by lamination. In addition, the second adhesive film may be additionally removed.

In the heating film including the first resin sheet, the content of the resin layer, the metal foil pattern, and the second adhesive film is the same as described above.

In an exemplary embodiment of the present application, the first resin sheet does not have adhesion properties to the adherend by itself, but is a substrate to which adhesion can be imparted after thermal lamination with the adherend at a temperature of 40° C. to 120° C. can In addition, after performing R2R thermal lamination with an adherend in the above temperature range, additional heat treatment at room temperature to 60°C for a predetermined time may be a substrate in which adhesion becomes stronger. More specifically, the first resin sheet may include a thermoplastic resin, and the thermoplastic resin may include at least one of polyvinyl butyral (PVB) and ethyl vinyl acetate (EVA). Also, the thickness of the first resin sheet may be 100 μm to 800 μm, 100 μm to 400 μm, 400 μm to 800 μm, and 300 μm to 500 μm.

In the exemplary embodiment of the present application, the difference in refractive index between the resin layer and the first resin sheet may be 0.03 or less and may be 0 or more.

In an exemplary embodiment of the present application, the resin layer means a layer formed by coating the composition for forming a resin layer, and the resin sheet means using a film form. In addition, as described above, the thickness of the resin layer is 3 μm to 50 μm, and the thickness of the resin sheet is 100 μm to 800 μm, and the resin layer and the resin sheet can be distinguished from each other.

A heating film according to an exemplary embodiment of the present application is schematically shown in FIGS. 1 and 2 below.

1, the heating film according to an exemplary embodiment of the present application has a structure in which a first adhesive film 10, a resin layer 20, a metal foil pattern 30, and a second adhesive film 40 are sequentially stacked. can have

2, the heating film according to an exemplary embodiment of the present application has a structure in which a first resin sheet 50, a resin layer 20, a metal foil pattern 30, and a second adhesive film 40 are sequentially stacked. can have

In addition, the method for manufacturing a heating film according to an exemplary embodiment of the present application includes the steps of: forming a resin layer having a thickness of 3 μm to 50 μm and a refractive index of 1.45 to 1.49 on a metal foil film; forming a first adhesive film on the resin layer; forming a metal foil pattern by patterning the metal foil film; and forming a second adhesive film on the metal foil pattern.

In an exemplary embodiment of the present application, the contents of the metal foil film, the resin layer, the first adhesive film, the second adhesive film, and the like are the same as described above.

In an exemplary embodiment of the present application, the first adhesive film includes a first plastic substrate and a first adhesive layer provided on the first plastic substrate, and the first adhesive layer is provided to be in contact with the resin layer The second adhesive film may include a second plastic substrate and a second adhesive layer provided on the second plastic substrate, and the second adhesive layer may be provided to be in contact with the metal foil pattern.

In an exemplary embodiment of the present application, when the thickness of the metal foil film is 5 μm or less, a carrier layer may be introduced on the back surface of the metal foil film for ease of handling. The carrier layer may be a copper foil or an aluminum foil.

In an exemplary embodiment of the present application, the step of forming the resin layer on the metal foil film may be performed by a coating method using a composition including the above-described material for a resin layer and a solvent capable of dissolving the same, and the coating The method may use comma coating, gravure coating, slot die coating, and the like. The solvent is not particularly limited as long as it is a solvent capable of dissolving the material for the resin layer, and for example, methanol, ethanol, isopropanol, methyl ethyl ketone, NMP, cellosolve-based substances, mixtures thereof, and the like may be used.

In an exemplary embodiment of the present application, the step of forming the first adhesive film on the resin layer may be performed by a lamination process.

In the exemplary embodiment of the present application, the step of forming the metal foil pattern by patterning the metal foil film may use a conventional resist patterning process known in the art. That is, after forming a resist pattern on the metal foil film, the metal foil pattern may be formed through an etching process.

In an exemplary embodiment of the present application, the step of forming the second adhesive film on the metal foil pattern may be performed by a lamination process.

In an exemplary embodiment of the present application, after the step of forming the second adhesive film, the step of removing the first adhesive film, and attaching the first resin sheet to the opposite surface of the surface on which the metal foil pattern of the resin layer is formed to do; and removing the second adhesive film.

The step of removing the first adhesive film may be performed as a process of removing the first adhesive film after UV or heat irradiation.

The step of attaching the first resin sheet may be performed by a roll-to-roll (R2R) thermal lamination process at 40°C to 120°C. After the roll-to-roll (R2R) thermal lamination, it is also possible to further heat-treat for 10 minutes to 1 day in an environment of room temperature to 70° C. to further impart adhesion.

In addition, the heating glass for a vehicle according to an exemplary embodiment of the present application, a first resin sheet; a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; and a heating film including a metal foil pattern provided on the resin layer; a first glass provided on one side of the heating film; and a second glass provided on the other side of the heating film.

In an exemplary embodiment of the present application, the first glass and the second glass are not particularly limited, and glass known in the art may be applied.

In the exemplary embodiment of the present application, a second resin sheet may be further included on at least one of a surface between the heating film and the first glass and a surface between the heating film and the second glass.

The second resin sheet by itself does not have adhesion properties to the adherend, but may be a substrate to which adhesion can be imparted after thermal lamination with the adherend at a temperature of 40°C to 120°C. More specifically, the first resin sheet may include a thermoplastic resin, and the thermoplastic resin may include at least one of polyvinyl butyral (PVB) and ethyl vinyl acetate (EVA). Further, the thickness of the second resin sheet may be 100 μm to 800 μm, 100 μm to 400 μm, 400 μm to 800 μm, and 300 μm to 500 μm. Also, the first resin sheet and the second resin sheet may include the same material or different materials.

In an exemplary embodiment of the present application, the haze of the heating glass for automobiles may be 0.3% to 2%.

According to an exemplary embodiment of the present application, a pair of opposing bus bars for applying electricity to the metal foil pattern may be further included.

According to an exemplary embodiment of the present application, a black pattern may be provided to conceal the bus bar. For example, the black pattern may be printed using a paste containing cobalt oxide. In this case, screen printing is suitable for the printing method, and the thickness may be set to 10 μm to 100 μm. The metal pattern and the bus bar may be respectively formed before or after the black pattern is formed.

The heating glass for a vehicle according to an exemplary embodiment of the present application may be connected to a power source for heat generation, and at this time, the amount of heat generated per m ² is preferably 100W to 1,000W, preferably 200W to 700W. In the heating glass for automobiles according to an exemplary embodiment of the present application, the heating element has excellent heating performance at a low voltage, for example, 30V or less, preferably 20V or less.

The heating glass for a vehicle according to an exemplary embodiment of the present application is schematically shown in FIGS. 3 and 4 below.

3, the heating glass for automobiles according to an exemplary embodiment of the present application is a first glass 60, a first resin sheet 50, a resin layer 20, a metal foil pattern 30 and a second glass ( 70) may have a sequentially stacked structure. In this case, a pair of bus bars 90 may be further included between the metal foil pattern 30 and the second glass 70 . In addition, the thickness of the first resin sheet 50 may be 400㎛ to 800㎛.

In addition, as shown in FIG. 4 below, the heating glass for automobiles according to an exemplary embodiment of the present application includes a first glass 60 , a second resin sheet 80 , a first resin sheet 50 , a resin layer 20 , The metal foil pattern 30 and the second glass 70 may have a structure in which they are sequentially stacked. In this case, a pair of bus bars 90 may be further included between the metal foil pattern 30 and the second glass 70 . In addition, the thickness of the first resin sheet 50 and the second resin sheet 80 may each independently be 100 μm to 400 μm. The first resin sheet and the second resin sheet may be made of the same material or different materials.

3 and 4, since the glass is left for a long time at high temperature and pressure when bonding, the space spaced apart from the glass by the thickness of the metal foil pattern and the bus bar can be filled by the resin layer and the first resin sheet, Since both the base layer and the first resin sheet may have the same refractive index, it may be difficult to distinguish the two in appearance after glass bonding. In addition, since the resin layer, the first resin sheet, and the second resin sheet may all have the same refractive index, it may be difficult to distinguish them visually after glass bonding.

In addition, as shown in FIG. 5 below, the heating glass for automobiles according to an exemplary embodiment of the present application is a first glass 60 , a first resin sheet 50 , a resin layer 20 , a metal foil pattern 30 , and a second The resin sheet 80 and the second glass 70 may have a structure in which they are sequentially stacked. In this case, a pair of bus bars 90 may be further included between the metal foil pattern 30 and the second resin sheet 80 . In addition, the thickness of the first resin sheet 50 and the second resin sheet 80 may each independently be 100 μm to 400 μm.

According to an exemplary embodiment of the present application, it is possible to omit the deposition process by using a metal foil film without forming a metal pattern by an expensive deposition process as in the prior art, thereby reducing the cost of fabric and manufacturing a heating film at low cost can do.

In addition, according to an exemplary embodiment of the present application, since a heatable metal foil pattern is directly supported on a roll-type PVB sheet rather than a PET film, a general laminated glass manufacturing process of bonding automotive glass with a PVB sheet is applied to form a metal foil pattern. Manufacturing of laminated glass based In addition, since the PET film is not inserted, it may be advantageous for bonding with glass having a large curvature, and it is possible to prevent distortion of the field of view due to the difference in refractive index between the PET film and PVB, which is a conventional problem.

In addition, since the heating glass for automobiles according to an exemplary embodiment of the present application uses a resin having the same refractive index as an interlayer of laminated glass as an adhesion layer, even if the roughness of the metal foil film is high, glass lamination After the haze is reduced, it is possible to improve the optical characteristics.

Hereinafter, the embodiments described in the present specification are illustrated by way of Examples. However, it is not intended that the scope of the above embodiments be limited by the following examples.

< Example >

< Example 1>

A coating solution having a composition of 12 parts by weight of PVB having a refractive index of 1.47 and a glass transition temperature (Tg) of 32 °C, 44 parts by weight of ethanol, and 44 parts by weight of methyl ethyl ketone is coated on the matt surface of a copper foil having a thickness of 8 µm, and then 120 °C, 5 After drying for minutes, a PVB coating layer having a thickness of 23 μm was formed on the matt surface of the copper foil.

Thereafter, the first adhesive film having a PET/adhesive layer structure having a peel strength of 18 gf/25 mm measured by the evaluation method of ASTM D3330 was laminated on the PVB side of the copper foil to prepare a substrate. At this time, the surface roughness (Rz) of the matt surface of the 8 μm copper foil on which the PVB coating layer was formed was 1.63 μm to 2.54 μm, and the first adhesive film was coated with a silicone-based first adhesive layer having a thickness of 5 μm on PET with a thickness of 100 μm. what was used was After washing/washing/drying the copper foil with 0.5 wt% sulfuric acid, dry film resist (DFR) having a thickness of 25 µm was laminated on the copper foil surface at 110°C. Thereafter, photolithography → development → etching → peeling process was performed to prepare a metal foil pattern film. At this time, a 0.2 wt% aqueous solution of potassium carbonate was used as the developer, an aqueous solution based on 20 wt% of iron chloride was used as the etching solution, and a 2% aqueous solution of sodium hydroxide was used as the stripper, and the line width of the copper foil pattern was 15 μm to 23 μm.

Thereafter, a second adhesive film having a peel strength of 173 gf/25 mm for copper foil was laminated on the metal foil pattern film surface, and then the first adhesive film was removed from the PVB coating layer through a delamination process. In this case, the second adhesive film is a 7㎛-thick acrylic second adhesive layer coated on 125㎛-thick PET, and has a peel strength of 160gf/25mm to 190gf/25mm before UV irradiation, but 25gf/25gf/ after UV irradiation A UV variable adhesive film that is lowered to less than 25 mm was used. However, unless otherwise stated, the evaluation was performed under UV blocking in order to remove the UV effect. After that, the PVB coating layer surface of the metal foil pattern film having the second adhesive film layer and the first adhesive film layer removed and the first PVB film having a thickness of 380 μm are attached by roll lamination on a rubber roll set at a temperature of 80° C. Thus, a structure of the first PVB film / PVB coating layer / copper foil pattern / second adhesive film was prepared.

Then, after removing the second adhesive film from the structure, the first PVB film surface of the structure from which the second adhesive film is removed on the first glass is laminated so that the first glass surface is in contact with the first glass, and the second adhesive film is The first and second bus bars made of copper foil having a width of 1 cm and a thickness of 50 μm were mounted on both ends of the upper part of the removed metal foil pattern film, where the pattern surface of the film was exposed, and then the first and second bus bars having a thickness of 380 μm were mounted to cover the pattern surface and the bus bar. 2 PVB films were laminated thereon, and a second glass was laminated thereon, followed by vacuum lamination at 120° C. for 20 minutes to prepare exothermic laminated glass in which a copper pattern was embedded between PVBs. The sheet resistance of the heat-generating laminated glass thus prepared was 0.22 ohm/sq.

< Example 2>

Exothermic laminated glass was prepared in the same manner as in Example 1, except for vacuum lamination at 120° C. for 20 minutes in Example 1, and further vacuum lamination at 140° C. for 20 minutes, and the sheet resistance at this time was 0.29 ohm/ sq was

< comparative example 1>

In Example 1, the step of providing a PVB coating layer having a thickness of 23 μm was omitted, and a first adhesive film having a peel strength of 173 gf/25 mm was laminated on the matt surface of an 8 μm copper foil having a surface roughness (Rz) value of 1.63 μm to 2.54 μm. . In this case, as the first adhesive film, the same as the second adhesive film applied in Example 1 was used. Thereafter, in a manner similar to Example 1, copper foil surface pretreatment → DFR lamination → photolithography → development → etching → peeling process was attempted to form a copper foil pattern layer on the first adhesive film, but the peel strength was 173 gf/25 mm instead of 18 gf/25 mm. patterning was not possible because the adhesion between the copper foil and the adhesive film was not sufficient despite the relatively high

< comparative example 2>

In Example 1, the step of providing a PVB coating layer having a thickness of 23 μm was omitted, and a first adhesive film having a peel strength of 173 gf/25 mm was laminated on a shiny surface having a surface roughness (Rz) value of 0.49 μm to 1.0 μm among 8 μm copper foil. . At this time, the first adhesive film was the same as the second adhesive film applied in Example 1 was used. Thereafter, in a manner similar to Example 1, copper foil surface pretreatment → DFR lamination → photolithography → development → etching → peeling process to form a copper foil pattern layer on the first adhesive film. At this time, when the line width of the copper foil was narrowed to 23 μm or less, the pattern was detached from the adhesive film, making it impossible to form a copper foil pattern film.

As described above, according to an exemplary embodiment of the present application, it is possible to omit the deposition process by using a metal foil film without forming a metal pattern by an expensive deposition process as in the prior art, thereby reducing the cost of the fabric and reducing the cost. A heating film can be manufactured with

In addition, according to an exemplary embodiment of the present application, since the heatable metal foil pattern is directly supported on the roll-type PVB film rather than the PET film, it is possible to manufacture laminated glass based on the metal foil pattern excluding the PET film, thus It may be advantageous for bonding with glass having a large curvature. In addition, it is possible to prevent distortion of the field of view due to the difference in refractive index between the PET film and PVB, which is a conventional problem.

In addition, since the heating glass for automobiles according to an exemplary embodiment of the present application uses a resin having the same refractive index as an interlayer of laminated glass as an adhesion layer, even if the roughness of the metal foil film is high, glass lamination After the haze is reduced, it is possible to improve the optical characteristics.

10: first adhesive film
20: resin layer
30: metal foil pattern
40: second adhesive film
50: first resin sheet
60: first glass
70: second glass
80: second resin sheet
90: bus bar

Claims (21)

a first adhesive film;
a resin layer provided on the first adhesive film, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49;
a metal foil pattern provided on the resin layer; and
and a second adhesive film provided on the metal foil pattern,
The peeling strength of the first adhesive film is 15gf/25mm to 300gf/25mm of the heating film. a first resin sheet;
a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49;
a metal foil pattern provided on the resin layer; and
and a second adhesive film provided on the metal foil pattern,
The ten-point average roughness (Rz) of the surface of the metal foil pattern in contact with the resin layer is 0.7 μm or more. a first resin sheet;
a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; and
It includes a metal foil pattern provided on the resin layer,
The ten-point average roughness (Rz) of the surface of the metal foil pattern in contact with the resin layer is 0.7 μm or more. The method according to claim 1, wherein the first adhesive film comprises a first plastic substrate and a first adhesive layer provided on the first plastic substrate,
The first adhesive layer is a heating film that is provided in contact with the resin layer. The heating film according to claim 4, wherein the first adhesive layer includes at least one of a silicone-based polymer and an acrylic polymer. delete The method according to any one of claims 1 to 3, wherein the resin layer comprises at least one of polyvinyl butyral (PVB), ethyl vinyl acetate (EVA), and an acrylate-based polymer,
The glass transition temperature (Tg) of the resin layer is a heating film of 25 ℃ to 80 ℃. The method according to any one of claims 1 to 3, wherein the line height of the metal foil pattern is 2㎛ to 15㎛,
The sheet resistance of the metal foil pattern is 0.05 ohm / sq to 0.5 ohm / sq of the heating film. The heating film according to any one of claims 1 to 3, wherein the metal foil pattern comprises an aluminum foil pattern or a copper foil pattern. The heating film according to claim 1, wherein the ten-point average roughness (Rz) of the surface of the metal foil pattern in contact with the resin layer is 0.7 μm or more. The heating film according to any one of claims 1 to 3, further comprising a blackening layer pattern on at least a portion of a surface of the metal foil pattern that is not in contact with the resin layer. The method according to claim 1 or 2, wherein the second adhesive film comprises a second plastic substrate and a second adhesive layer provided on the second plastic substrate,
The second adhesive layer is a heating film that is provided in contact with the metal foil pattern. The heating film according to claim 1, wherein the peeling strength of the second adhesive film is greater than the peeling strength of the first adhesive film. The method according to claim 1, wherein the peel strength of at least one of the first adhesive film and the second adhesive film is in the range of 100gf/25mm to 300gf/25mm before UV or heat irradiation, 15gf/25mm to 90gf/25mm after UV or heat irradiation A heating film that changes within the range of The method according to claim 2 or 3, wherein the first resin sheet comprises at least one of polyvinyl butyral (PVB) and ethyl vinyl acetate (EVA),
The first resin sheet has a thickness of 100 μm to 800 μm. forming a resin layer having a thickness of 3 μm to 50 μm and a refractive index of 1.45 to 1.49 on the metal foil film;
forming a first adhesive film on the resin layer;
forming a metal foil pattern by patterning the metal foil film; and
Forming a second adhesive film on the metal foil pattern
As a method for producing a heating film comprising a,
The ten-point average roughness (Rz) of the surface of the metal foil pattern in contact with the resin layer is 0.7 μm or more. The method according to claim 16, wherein the first adhesive film comprises a first plastic substrate and a first adhesive layer provided on the first plastic substrate, the first adhesive layer is provided to be in contact with the resin layer,
The second adhesive film includes a second plastic substrate and a second adhesive layer provided on the second plastic substrate, wherein the second adhesive layer is provided to be in contact with the metal foil pattern. The method according to claim 16, After forming the second adhesive film,
removing the first adhesive film;
attaching a first resin sheet to the opposite surface of the resin layer on which the metal foil pattern is formed; and
Method for producing a heating film further comprising the step of removing the second adhesive film. a first resin sheet; a resin layer provided on the first resin sheet, having a thickness of 3 μm to 50 μm, and a refractive index of 1.45 to 1.49; and a heating film including a metal foil pattern provided on the resin layer;
a first glass provided on one side of the heating film; and
A second glass provided on the other side of the heating film
As a heating glass for automobiles comprising a,
The ten-point average roughness (Rz) of the surface in contact with the resin layer of the metal foil pattern is 0.7 μm or more. The heating glass for automobiles according to claim 19, further comprising a second resin sheet on at least one of a surface between the heating film and the first glass and a surface between the heating film and the second glass. The method according to claim 20, wherein the second resin sheet comprises at least one of polyvinyl butyral (PVB) and ethyl vinyl acetate (EVA),
The second resin sheet has a thickness of 100 μm to 400 μm.

Images