KR101918351B1 - Cover having metallic luster - Google Patents

Abstract

1. A radio wave transmission type cover which is provided on a front grill of a vehicle and has a metallic luster for transmitting a radar wave, comprising: a transparent resin layer exposed on a front surface of the front grill; a metal oxide formed on the rear side of the resin layer, A metallic texture layer composed of an alternately laminated multilayer optical film layer and a germanium (Ge) layer and showing reflected light of a metallic texture, and an opaque paint layer formed behind the metallic texture layer to improve the reflectance of the metallic texture layer .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a COVER HAVING METALIC LUSTER

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a radio wave transmissive cover having metallic luster, and more particularly, to a radio wave transmissive cover having metallic luster that protects an SCC radar and transmits radio waves.

The Smart Cruise Control (SCC) system is a system that detects the movement of the preceding vehicle by the radar mounted on the front of the vehicle and controls the engine and the brake accordingly to maintain the distance from the preceding vehicle.

The SCC radar, which is the core of this system, is most advantageous in terms of securing performance in front of the vehicle. Radiator grilles, automobile manufacturers' emblems, ornaments are often located at the center of the front of the vehicle .

Typically, the radiator grille is made of metal and plated with chromium to prevent corrosion.

However, since metal has low radio wave permeability, the transmission and reception of radio waves of the SCC radar are adversely affected. Accordingly, a method has been attempted in which a part of the radiator grille is replaced with a separate radar cover so that radio wave transmission and reception can be performed smoothly, thereby ensuring radio wave permeability.

However, since the radar cover is manufactured by excluding the metal to ensure radio wave permeability, there is a problem that the design continuity with the radiator grill made of metal is lost.

In order to solve this problem, a technique has been developed in which a metallic texture is realized by applying indium or tin, which is excellent in radio wave permeability, to a part of a radar cover.

As shown in FIG. 1, a conventional SCC cover is formed by applying a black paint for exposing only a part showing a metallic texture to a PC transparent layer, depositing indium thereon, .

However, since indium or tin is a relatively expensive material, the overall price of the radar unit is increased, and the melting point of the material is low, so that there is a problem that the durability of the cover may be deteriorated due to the environmental characteristics adjacent to the automobile engine.

It should be understood that the foregoing description of the background art is merely for the purpose of promoting an understanding of the background of the present invention and is not to be construed as an admission that the prior art is known to those skilled in the art.

Korean Patent Publication No. 10-2015-0095411 (Aug. 21, 2015)

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a metal luster which does not cause thermal deformation at high temperature, realizes metal texture while maintaining radio wave permeability, And an electromagnetic wave transmission type cover.

According to an aspect of the present invention, there is provided a radio wave transmission type cover having metallic luster according to an embodiment of the present invention. The radio wave transmission type cover is provided on a front grill of a vehicle and has metallic luster that transmits radar waves. A metal texture layer formed of a multilayer optical film layer and a germanium (Ge) layer, which are alternately laminated with metal oxides having different refractive indexes, formed behind the resin layer and exhibiting reflected light of a metal texture; And an opaque coating layer formed behind the textured layer to improve the reflectance of the metallic textured layer.

Wherein the multilayer optical film layer is constituted by alternately laminating a high refractive index layer made of any one of TiO ₂ and Cr ₂ O ₃ and a low refractive index layer made of SiO ₂ and the closest layer of the layers constituting the multilayer optical film layer Layer is a high-refraction layer composed of TiO ₂ .

The metal texture layer has a reflectance of 30% or more in a visible light region (wavelength: 400 to 700 nm) and a reflectance variation of 5% P or less in a visible light region.

The high refraction layer and the low refraction layer are each formed to a thickness of 10 to 200 nm, and the multilayer optical film layer is formed of three or more layers so that the total thickness is 300 nm to 10 μm.

The germanium layer is formed on at least one selected from a surface contacting the front side of the multilayer optical film layer, a surface contacting the rear side of the multilayer optical film layer, and a surface between the alternately stacked high refractive index layer and the low refractive index layer .

The germanium layer is formed on at least one selected from a surface contacting the front side of the multilayer optical film layer, a surface contacting the rear side of the multilayer optical film layer, and a surface between the alternately stacked high refractive index layer and the low refractive index layer .

The germanium layer has a total thickness of 50 nm to 5 탆.

The resin layer is characterized by having a planar or curved front surface without concavities and convexities and a rear surface formed with curved and convex portions to be bent.

And a primer layer formed between the resin layer and the metal texture layer.

And a masking layer formed between the resin layer and the metal texture layer and covering a portion of the metal texture layer, wherein the masking layer is an opaque paint covering the remaining part except for a part showing a predetermined shape .

According to the radio wave transmission type cover having metallic luster according to the present invention, the following effects can be obtained.

First, the reflected light of the metal texture can be realized on the radar cover by applying the ceramic metal oxide and the semiconductor germanium.

Second, the high radio wave permeability of ceramics and semiconductors applied to radar covers makes it possible to smoothly transmit and receive the SCC radar.

Second, thermal deformation at a high temperature can be prevented by using a metal oxide having high melting point and germanium.

Third, it provides the reflection light of a metal texture similar to a car radiator grill, so that the continuity and consistency of the appearance of the automobile can be maintained.

Fourthly, even if it has a curved and three-dimensional shape, it is possible to realize a metallic texture of an achromatic color by maintaining a certain reflectance and a deviation of less than a predetermined value.

FIG. 1 shows a conventional SCC cover using indium deposition,
FIGS. 2 to 4 are views showing the structure of a radio wave transmitting cover having metallic luster according to various embodiments of the present invention;
5 is a graph showing changes in radio wave permeability according to the number of layers of the multilayer optical film layer,
6 is a graph showing changes in radio wave permeability according to the thickness of the germanium layer,
FIG. 7 is a photograph showing the surface deformation of Comparative Examples 7, 8 and 11 after heat treatment at 220.degree. C. for 5 minutes, respectively.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms as used herein include plural forms as long as the phrases do not expressly express the opposite meaning thereto. Means that a particular feature, region, integer, step, operation, element and / or component is specified, and that other specific features, regions, integers, steps, operations, elements, components, and / And the like.

Unless otherwise defined, all terms including 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. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or very formal meanings unless defined otherwise.

Hereinafter, a radio wave transmission type cover having metallic luster according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a simplified cross-sectional view of one embodiment of the present invention. As shown in the figure, the electromagnetic wave-transmitting cover having metallic luster according to the present invention has a substantially transparent resin layer 10, a metallic texture layer 100a capable of reflecting reflected light of a metallic texture, And an opaque coating layer (50). Additionally, a primer layer 20 may further be provided between the resin layer 10 and the metal texture layer 100a.

The resin layer 10 is a layer formed of a transparent plastic such as polycarbonate, acrylic resin or the like, and constitutes the outermost portion of the cover according to the present invention, that is, the front surface of the vehicle.

At this time, since the resin layer 10 is formed to be transparent, external light is transmitted to the metal texture layer 100a while protecting the metal texture layer 100a, or reflected light of the metal texture reflected from the metal texture layer 100a Can be transmitted to the outside.

The front surface of the resin layer 10 is formed into a flat or curved surface smooth without bending, and a rear surface is formed with irregularities to be bent. At this time, it is preferable that the curved shape of the rear surface is formed in a shape having continuity with the shape of the surrounding radiator grill, an ambulance, a symbol of the automobile manufacturer, or the like.

When the metal texture layer 100a is formed on the curved surface of the rear surface of the resin layer 10, a three-dimensional metallic texture reflection light region having a desired shape can be obtained.

The metal texture layer 100a is divided into a multilayer optical film layer 30a and a germanium layer 40a. The multilayer optical film layer 30a is formed by alternately laminating metal oxides having different refractive indexes, that is, ceramics, ) Is a layer formed of germanium (Ge) which is a semiconductor.

The metal texture layer 100a thus formed can exhibit reflected light of a metal texture and exhibits high radio wave permeability because it has a lower electrical conductivity than a general metal.

The multilayer optical film layer (30a) of the structure of the metal texture layer (100a) has a refractive index higher materials such as TiO _2, Cr ₂ O _3, etc., for the high refractive index layer, a low refractive index material, for example formed of formed of a SiO ₂ It is preferable that the low refractive layers are alternately laminated. When the high refractive index layer and the low refractive index layer are alternately stacked, the reflectance in the visible light region is kept constant, so that achromatic metallic texture reflected light can be obtained.

To construct the multi-layer optical film (30a), in particular closest to the location and the resin layer 10, it is preferable to place the high refractive index layer composed of TiO _2. This is because the adhesion of TiO ₂ is higher than that of other materials, so that it is possible to lower the possibility of peeling between the resin layer 10 and the multilayer optical film layer 30a by first depositing TiO ₂ on the resin layer 10 have. SiO ₂ is required to ensure scratch resistance of the multilayer optical film layer 30a because of its high hardness, and it helps to reproduce the reflection light peculiar to the metal as a low refractive material.

The thickness of each of the high refractive index layer and the low refractive index layer of the multilayer optical film layer 30a is controlled to be in the range of 10 to 200 nm and the total thickness is controlled in the range of 300 nm to 10 占 퐉. The metallic texture reflection light can be displayed while minimizing the sense of heterogeneity.

The germanium layer 40a is a structure for further strengthening the metallic reflection light generated in the multilayer optical film layer 30a. Since the germanium has a dark colored metal texture in its own characteristics, the metallic texture layer 100a formed by the multi-layer optical film layer 30a and the germanium layer 40a has a dark chromatic color metallic reflection light slightly darker than ordinary chrome reflection light . This dark chrome color helps to make the appearance of the part more luxurious.

When the thickness of the germanium layer 40a is 10 占 퐉 or more, it is preferable to form the germanium layer 40a so as to have a thickness of 5 占 퐉 or less which does not deteriorate the radio wave permeability because the permeability of the radar wave is greatly reduced. On the other hand, when the thickness of the germanium layer 40a is less than 50 nm, the effect of strengthening the metallic texture reflected light generated in the multilayer optical film layer 30a can not be expected. Therefore, the thickness of the germanium layer 40a should satisfy the range of 50 nm to 5 占 퐉.

The germanium layer 40a is formed between the rear surface of the multilayer optical film layer 30a, that is, between the multilayer optical film layer 30a and the coating layer 50. In other embodiments of the present invention, the germanium layer 40a may vary in installation position. This will be described later.

The visible light reflectance of the entire metal texture layer 100a made of the multilayer optical film layer 30a and the germanium layer 40a described above satisfies 30% or more and the reflectance variation in the visible light region is 5% It is necessary to obtain a metallic texture reflection light without a dichromatic sensation (a phenomenon in which a specific color becomes prominent).

As described above, the rear surface of the resin layer 10 is formed to be bent, and the metal texture layer 100a is formed on the curved surface. The dichroic feeling generated by the deviation of the reflectance easily appears on the surface that is three-dimensionally curved as compared with the plane. Therefore, the reflectance and the deviation thereof defined in the present invention must satisfy the irregularity of the back surface of the resin layer 10, It can reflect light.

The paint layer 50 is formed of an opaque paint and is preferably formed of a black paint and formed on the rear surface of the metal texture layer 100a so as to improve the reflectance of the metal texture layer 100a, As shown in FIG.

By forming the paint layer 50 behind the metal texture layer 100a, the brightness of reflected light of the metal texture realized by the metal texture layer 100a can be improved and the environmental resistance and scratch resistance can be secured can do.

In addition to the above-described configurations, a primer layer 20 may be additionally provided between the resin layer 10 and the metal texture layer 100a. The primer layer 20 can impart a glossy or non-glossy effect to the reflected light of the metal texture generated in the metal texture layer 100a, thereby providing a more luxurious appearance.

Although not shown, a masking layer may be formed between the resin layer 10 and the multi-layer optical film layer 30a. The masking layer may be formed of an opaque coating material, preferably a black paint.

The masking layer may cover a portion of the multi-layered optical film layer 30a to restrict a region where the metallic texture reflected light is exposed to the outside, thereby forming a predetermined shape. Such forms may be radiator grills, ambulances, emblems, and the like. The area where the metallic texture reflection light is exposed may be formed into a three-dimensional shape through the combination of the curved rear surface shape of the resin layer 10 and the masking layer described above.

In the embodiment of the present invention, the masking layer is used to limit the region where the metallic texture reflected light is exposed. However, the present invention is not limited to this, and the metal texture may be realized through various methods such as etching the metallic texture layer 100a itself You will be able to limit the area.

The laminated structure of the metal texture layer according to the present invention is not limited to the embodiment shown in Fig. 2 but may be modified as shown in Figs. 3 and 4.

3, the germanium layer 40b may be formed between the resin layer 10 and the multilayer optical film layer 30b to form the metal texture layer 100b. As shown in FIG. 4, The germanium layer 40c may be formed between the multilayer optical film layers 30c to form the metal texture layer 100c.

When the germanium layer 40c is formed between the multilayer optical film layers 30c, it is preferable to form the germanium layer 40c between the high refractive index layer and the low refractive index layer of the multilayer optical film layer 30c.

The method of forming the metal texture layers 100a, 100b, and 100c in the present invention is not limited to a specific method. For example, the metal texture layers 100a, 100b, and 100c may be deposited and sputtered on the resin layer 10 through a PVD or PACVD process.

That is, to a plasma of Ar gas in a vacuum and the cleaning and activating the resin layer 10 surface, specifically the rear applying a bias (Bias) to give increasing the base material and the deposited interlayer adhesion, high refractive index materials (TiO _2, Cr ₂ O ₃ (E-Beam) is irradiated to a sample of a low refractive index material (SiO ₂ ) and a low refractive index material (SiO ₂ ) to form a multilayer optical film layer 30a on the surface of the resin layer or an electron beam is irradiated to a germanium ). ≪ / RTI >

Hereinafter, effects according to various embodiments of the present invention will be described.

Generally, car exterior radiator grill is chrome plated. Therefore, in order to realize a metal texture similar to that of a radiator grille, it is necessary to realize a reflectance similar to that of chrome. The reflectance of the metal texture layer 100a composed of the multilayer optical film layer 30a and the germanium layer 40a which is an embodiment of the present invention, reflectance of chromium in general, reflectance of the tin deposition layer in the prior art, 700 nm) were calculated by the Macleod analysis program and the results are shown in Table 1.

Comparative Examples 1 to 5 shown in Table 1 are samples in which each material is formed as a single layer on a resin layer. Examples 1 to 4 are the samples in which the resin layer 10, the primer layer 20, Only the number of layers of the multilayer optical film layer 30a was differently manufactured as a sample prepared in this order of the optical film layer 30a, the germanium layer 40a and the paint layer 50. [

Based on the reflectance of chromium shown in Comparative Examples 1 to 3 shown in Table 1, it can be seen that the reflectance in the visible light region is not less than 30% and the maximum-minimum deviation of the reflectance is not more than 5% . This means that in order to realize the chrome texture, it is necessary to have a brightness of more than a certain level, that is, 30% or more, and to have a uniform visible light reflectance over the entire area.

The tin shown in Comparative Example 4 has a low reflectance deviation and can generate an achromatic metallic texture reflected light. However, it can be seen that the total reflectance is less than 30% and the luminance is insufficient. In addition, it can be seen that the germanium shown in Comparative Example 5 exhibits a lower overall reflectance due to the specific dark color.

In contrast, in Examples 1 to 4, in which the total thickness of the multilayer optical film layer 30a was 300 nm or more and the number of layers was 3 or more, the reflectance in the visible light region was 30% or more and the reflectance deviation was 5% Able to know. At this time, the higher the number of layers of the multilayer optical film layer 30a, the higher the overall reflectance in the visible light region, the brighter reflected light can be exhibited, and the reflectance deviation in all embodiments is 5% .

The results of measuring the radio wave permeability of Examples 1 to 4 of Table 1 are shown in Fig. It can be seen that the radar wave transmittance of a frequency of 76 to 77 GHz and a wavelength of 400,000 nm (dotted line rectangular area) used for SCC radar propagation is close to 100% even if the number of layers of the multilayer optical film 30a is increased. This is because the multilayer optical film layer 30a does not interfere with radar propagation because it is a metal oxide, that is, a ceramic material, and there is almost no difference in radio wave permeability according to its thickness.

On the other hand, as shown in FIG. 6, when the thickness of the germanium layer 40a exceeds 5 占 퐉 and reaches 10 占 퐉, the radar wave transmittance at a frequency of 76 to 77 GHz and a wavelength of 400,000 nm (dotted rectangle) Able to know. Although germanium is a semiconductor, when it has a thickness equal to or more than a certain level, conductivity is developed to interfere with the transmission of radar waves. Therefore, the thickness of the germanium layer 40a is preferably limited to 5 mu m or less.

Table 2 shows the results of measurement of radar propagation attenuation and linearity by fabricating a sample of the metal texture layer 100a and a conventional indium-coated sample manufactured according to the present invention.

Each sample was prepared by depositing an object on a 1 mm thick PC board. In Comparative Example 6, indium (In) was deposited. Examples 5 to 7 each consisted of a germanium layer 40a and a multilayer optical film layer 30a. The multilayer optical film layer 30a had three layers, seven layers, 15 floors.

The radar waves used were 76 ~ 77GHz and the attenuation and refraction angles were measured using a RAS (Radar Alignment System) measuring device.

As shown in Table 2, the radio wave transmission performance of the samples of the metal texture layer 100a according to Examples 5 to 7 was evaluated in terms of the radio wave transmission performance of the indium-coated samples according to Comparative Example 6, And the linearity of the radar beam was found to be equal or superior to that of the radar beam.

For reference, the radar attenuation factor suitable for the cover according to the present invention is preferably -4 dB or less (-4 to 0 dB) on a round trip basis and -1.8 dB or less (-1.8 to 0 dB) on a one-way basis.

The actual cover samples were prepared for each of the embodiments shown in FIGS. 2 to 4, and the results of analyzing the reflectance of each sample through the macleod analysis program are shown in Table 3.

The multilayer optical film layers 30a, 30b and 30c applied to the respective samples are formed in the same manner as the five layers and only the positions of the germanium layers 40a, 40b and 40c are arranged on the back surface (coating layer direction) Layer direction) and intermediate (between the high refractive index layer and the low refractive index layer).

As a result, although the metal texture layer 100b having the germanium layer 40b formed on the rear surface of the multilayer optical film layer 30b, that is, Example 8 showed the highest reflectance, the visible light reflectance of all the samples was 38 to 44% And reflectance of 30% or more. Also, it was confirmed that the reflectance deviation of the visible light region of all the samples was not more than 5% P and that the metallic reflected light of achromatic color was exhibited.

Table 4 shows the attenuation ratio and the linearity of each sample in which the reflectance was measured in Table 3 using a RAS measuring device at a frequency of 76 to 77 GHz and a wavelength of 400,000 nm for one-way transmission.

As a result of the evaluation, it was confirmed that the attenuation ratio and the linearity of the radar wave did not greatly vary according to the position of the germanium layer as shown in Table 4, and that the performance was constant.

FIG. 7 shows the results of examining the high temperature durability by preparing samples of the metal texture layer 100a according to the present invention, indium coated and germanium coated samples, respectively.

Each sample was prepared by depositing an object on a glass substrate, Comparative Example 7 was made of indium, Comparative Example 8 was made of germanium, Example 11 was made of a multilayer optical film layer 30a and a germanium layer 40a. Then, each sample was heat-treated at 220 ° C for 5 minutes in order to measure the environmental resistance at a high temperature, and the degree of deformation of the deposition surface was confirmed. In Comparative Example 7, many cracks were generated on the surface and deformation occurred. On the other hand, in Comparative Example 8 and Example 11, surface cracks did not occur.

As shown in FIG. 7 and Table 5, since metal oxides such as germanium or TiO ₂ and SiO ₂ have a higher melting point than indium, they are not deformed even when exposed to a high temperature environment. The vehicle radiator grille is close to the engine and is always exposed to high temperatures. As a result, the materials applicable to the present invention can be applied instead of indium having low melting point to improve durability and service life.

In Comparative Example 8 using only germanium, thermal deformation such as surface cracks did not occur, but dark color was shown as compared with Example 11. This is because the reflectance of germanium is low as shown in Comparative Example 5 of Table 1, so that the brightness of reflected light is lowered.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

10: Resin layer
20: Primer layer
30a, 30b, and 30c: multilayer optical film layers
40a, 40b, 40c: a germanium layer
50: paint layer
100a, 100b, 100c: metal texture layer

Claims (9)

1. A radio wave transmission type cover which is provided on a vehicle front grille and has metallic luster for transmitting radar waves,
A transparent resin layer exposed on a front surface of the front grill;
A metal texture layer formed behind the resin layer and composed of a multilayer optical film layer and a germanium (Ge) layer in which metal oxides having different refractive indices are alternately stacked, and which reflects light of a metal texture; And
And an opaque coating layer formed behind the metal texture layer to improve the reflectance of the metal texture layer,
Wherein the metal texture layer has a reflectance of 30% or more in a visible light region (wavelength: 400 to 700 nm) and a reflectance variation of 5% or less in a visible light region.
The method according to claim 1,
Wherein the multilayer optical film layer is constituted by alternately laminating a high refractive index layer made of any one of TiO ₂ and Cr ₂ O ₃ and a low refractive index layer made of SiO ₂ ,
Wherein the layer closest to the resin layer among the layers constituting the multilayer optical film layer is a high-refraction layer made of TiO ₂ .
delete The method of claim 2,
The high refractive index layer and the low refractive index layer are each formed to a thickness of 10 to 200 nm,
Wherein the multilayer optical film layer is formed of three or more layers and has a total thickness of 300 nm to 10 占 퐉.
The method of claim 2,
Wherein the germanium layer is formed on at least one selected from a surface in contact with the front side of the multilayer optical film layer, a surface in contact with the rear side of the multilayer optical film layer, and a surface between the alternately stacked high refractive index layer and low refractive layer. , A radio-transmissive cover having a metallic luster.
The method of claim 5,
Wherein the germanium layer has a total thickness of 50 nm to 5 占 퐉.
The method according to claim 1,
Wherein the resin layer has a planar or curved front surface without irregularities and a rear surface formed with curved portions and convex portions to be bent.
The method according to claim 1,
And a primer layer formed between the resin layer and the metal texture layer.
The method according to claim 1,
Further comprising a masking layer formed between the resin layer and the metal texture layer to cover a portion of the metal texture layer,
Characterized in that the masking layer is an opaque coating material that covers other portions except for a portion showing a predetermined shape.

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