KR20200074749A - Electromagnetic wave transmitting cover and method of manufacturing the same - Google Patents

Abstract

Provided is an electromagnetic wave transmitting cover including a transparent resin layer, a metal composite film layer, and a base layer. The transparent resin layer is a cured product of a composition including: a main material including a polyol compound having three hydroxy groups; and a curing agent including an isocyanate compound having at least two isocyanate groups per one molecule. The transparent resin layer has pencil hardness of 6H to 7H.

Description

Electromagnetic wave transmission cover and its manufacturing method{ELECTROMAGNETIC WAVE TRANSMITTING COVER AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to an electromagnetic wave transmission cover and a method for manufacturing the same.

The auto cruise control system is a technology that measures the inter-vehicle distance or relative speed between the vehicle in front and the host vehicle by a sensor mounted in front of the vehicle, controls the brakes based on this information, and controls the inter-vehicle distance while accelerating/decelerating the host vehicle. As a sensor used in an auto cruise control system, a radar device, which is an electromagnetic wave transmitting and receiving device such as a millimeter wave radar, is generally used. The radar device mounted on the front of the vehicle body should be installed unrecognized from the outside without damaging the exterior of the vehicle. Accordingly, it is required to position the electromagnetic wave transmission cover between the radar device and the front grill, and to provide excellent esthetics by providing continuity to the metallic luster represented by the front grill with little electromagnetic transmission loss and excellent metallic luster.

On the other hand, the electromagnetic wave transmission cover is exposed to the exterior of the vehicle along with the front grill, and thus it is easy to generate scratches or cracks on the surface due to mechanical, physical, and chemical effects. Accordingly, there is a problem that the performance and aesthetics of the electromagnetic wave transmission cover are deteriorated. Accordingly, an electromagnetic wave transmission cover having excellent physical properties such as self-recovery is required to maintain product quality. The self-recovery property refers to a property in which damage such as scratches is gradually cured or reduced by itself when damage such as scratching occurs on the coating layer as external physical force or stimulus is applied to the coating layer. Refers to.

However, in the case of the existing coating layer exhibiting such self-recovery, there is a problem that mechanical properties of the coating layer, such as hardness, wear resistance, or coating film strength, are significantly deteriorated.

An object of the present invention is to provide an electromagnetic wave transmission cover comprising a transparent resin layer having excellent hardness and self-recovery.

In addition, an object of the present invention is to provide a method for manufacturing an electromagnetic wave transmission cover that simplifies the process and provides cost competitiveness, while providing excellent hardness and self-recovery.

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be readily appreciated that the objects and advantages of the present invention can be realized by means of the appended claims and combinations thereof.

The subject includes a transparent resin layer, a metal composite film layer and a base layer according to the present invention, the transparent resin layer comprising a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule. It is a cured product of a composition comprising, and can provide an electromagnetic wave transmission cover having a pencil hardness of 6H to 7H of the transparent resin layer.

In addition, each step of preparing a subject comprising a polyol compound having three hydroxy groups according to the present invention and a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule; Preparing a first injection material comprising a metal composite film and a base layer; Including the step of putting the first injection material into a mold, adding a composition containing the subject and the curing agent, and curing to prepare a second injection material including a transparent resin layer, wherein the pencil hardness of the transparent resin layer is It is possible to provide a method for manufacturing an electromagnetic wave transmission cover that is 6H to 7H.

The electromagnetic wave transmission cover according to the present invention may simultaneously exhibit excellent hardness and self-recovery while being transparent, including a transparent resin layer. In addition, the electromagnetic wave transmission cover has a low electromagnetic wave transmission loss, and it is possible to continuously exhibit excellent aesthetics by imparting continuity to the metallic luster of the front grill with excellent metallic luster.

In addition, the method of manufacturing the electromagnetic wave transmission cover according to the present invention can simplify the process and impart cost competitiveness without impairing the function of the electromagnetic wave transmission cover, and providing excellent hardness and self-recovery.

In addition to the above-described effects, the concrete effects of the present invention will be described together while describing the specific matters for carrying out the invention.

The above-described objects, features, and advantages will be described in detail below, and accordingly, a person skilled in the art to which the present invention pertains can easily implement the technical spirit of the present invention. In the description of the present invention, when it is determined that detailed descriptions of known technologies related to the present invention may unnecessarily obscure the subject matter of the present invention, detailed descriptions will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail.

In the following, any configuration is placed in the "upper (or lower)" or "upper (or lower)" of the component under induction heating and nothing in accordance with some embodiments of the present invention. In addition to being disposed in contact with the top (or bottom) of this component, it may mean that other components may be interposed between the component and any component disposed on (or under) the component. .

Hereinafter, an electromagnetic wave transmission cover according to some embodiments of the present invention will be described.

One embodiment of the present invention includes a transparent resin layer, a metal composite film layer and a base layer, the transparent resin layer is a subject comprising a polyol compound having three hydroxyl groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule. It is a cured product of a composition comprising, and provides an electromagnetic wave transmission cover having a pencil hardness of 6H to 7H of the transparent resin layer.

The electromagnetic wave transmission cover is located between the radar device mounted on the front of the vehicle body and the front grill, and it is required to exhibit excellent aesthetics by providing continuity to the metallic luster represented by the front grill with low electromagnetic wave transmission loss and excellent metallic luster. .

In addition, the electromagnetic wave transmission cover is exposed to the exterior of the vehicle along with the front grill, and is prone to surface scratches or cracks due to mechanical, physical, and chemical effects. Accordingly, an electromagnetic wave transmission cover having excellent physical properties such as self-recovery is required to maintain product quality. The self-recovery property refers to a property in which damage such as scratches is gradually cured or reduced by itself when damage such as scratching occurs on the coating layer as external physical force or stimulus is applied to the coating layer. Refers to.

However, in the case of the existing coating layer exhibiting such self-recovery, there is a problem in that mechanical properties such as hardness are significantly deteriorated.

The electromagnetic wave transmission cover including a transparent resin layer, a metal composite film layer, and a base material layer includes a subject comprising a polyol compound having three hydroxyl groups as the transparent resin layer; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule; and a cured product of a composition comprising, it may exhibit pencil hardness of 6H to 7H with excellent self-recovery.

The electromagnetic wave transmission cover includes a substrate layer, the substrate layer is located adjacent to the radar device, and can improve the strength of the electromagnetic wave transmission cover. The base layer may be opaque to prevent the radar device from being recognized in front of the vehicle, thereby preventing spoiling, and exhibit excellent transmittance to electromagnetic waves emitted from the radar device and reflected from the object.

The base layer is acrylonitrile Butadiene Styrene (ABS), acrylonitrile Styrene Acrylate (ASA), acrylonitrile ethylene propylene rubber styrene (AES) And a resin injection material selected from the group consisting of and combinations thereof.

The electromagnetic wave transmission cover is a molded article having a complex three-dimensional structure according to the shape or emblem of a front grill convexly located in front of the vehicle, and the electromagnetic wave transmission cover is a metal layer that implements a metal color such as a front grill and/or an emblem and its surroundings It includes a metal composite film layer including a printed layer to implement the dark color of. The metal composite film layer includes a metal layer on which a metal such as indium or tin is deposited, and electromagnetic waves in a region of about 78 GHz, which is a frequency of a radar device, are well transmitted, resulting in low electromagnetic loss, and continuity to the metallic luster of the front grill with excellent metallic luster. By giving it can show excellent aesthetics.

In addition, the electromagnetic wave transmission cover includes a transparent resin layer, and transmits electromagnetic waves well, so that the metallic luster can be recognized well outside the vehicle, and protects the metal layer and the printed layer formed by metal deposition to prevent the front grille. Continuity can be given to the metallic luster to show excellent appearance.

In general, the transparent resin layer of the electromagnetic wave transmission cover includes polymethyl methacrylate (PMMA) or polycarbonate (PC). However, the polymethyl methacrylate is easily damaged, and the polycarbonate has poor physical properties such as hardness and abrasion resistance, and thus there is a problem that it is not suitable as a transparent resin layer of the electromagnetic wave transmission cover exposed to the exterior of the vehicle along with the front grill.

Accordingly, in the related art, an additional hard coating layer was added to the transparent resin layer containing polycarbonate to solve this.

However, since the physical properties of the polycarbonate resin layer itself are low, and a separate hard coating layer has to be laminated, the process is complicated and there is a non-economical problem. In addition, even if a hard coating layer was applied, there was a problem that desired physical properties were not sufficiently obtained. And, in general, the electromagnetic wave transmission cover is manufactured by in-mold injection molding. At the time of manufacturing each layer, a high-temperature composition is injected, and injection is performed at a high temperature, such that a heat-resistant tape must be attached to protect the metal composite film layer. There was a cumbersome and expensive problem due to the need for an additional process.

The electromagnetic wave transmission cover is a subject comprising a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule; including a transparent resin layer that is a cured product of a composition comprising, maintaining a function of an electromagnetic wave transmission cover with excellent transparency, and a separate hard coating layer. It can exhibit excellent self-recovery properties and excellent pencil hardness of 6H to 7H at the same time.

Therefore, the electromagnetic wave transmission cover is exposed to the exterior of the vehicle to prevent scratches or cracks on the surface due to mechanical, physical, and chemical effects, and even when damage occurs, such as scratches, it gradually heals or decreases itself and transmits electromagnetic waves The function of the cover can be maintained.

The transparent resin layer is a subject containing a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule.

The subject includes a polyol compound having three hydroxy groups and can impart hardness and self-recovery with excellent transparency. For example, when the polyol compound has two hydroxy groups, the degree of crosslinking is poor, so that the hardness and self-recovery of the transparent resin layer may not be sufficiently improved. In addition, when a polyol compound having four or more hydroxy groups is included, yellowing may easily occur due to heat and ultraviolet rays. Accordingly, the metallic luster is not well recognized from the outside of the vehicle, and there may be a problem that design is deteriorated.

The polyol compound may include one compound formed from the group consisting of polyester-based polyol, lactone-based polyol, polycarbonate-based polyol, polyether-based polyol, and combinations thereof. Specifically, the polyol compound may be a polyether polyol.

The glass transition temperature of the polyether polyol compound may be about 70° C. to about 80° C. The glass transition temperature may be measured by differential scanning calorimetry (DSC). For smooth mixing of the main material and the curing agent, it must be blended by heating at a temperature above the glass transition temperature.

The electromagnetic wave transmission cover is manufactured by reaction in molding (RIM) at about 60° C. to about 90° C., as described below, to secure cost competitiveness, and to protect the metal composite film without attaching a heat resistant tape or the like. .

The subject can smoothly mix with a curing agent, including a polyol compound having a glass transition temperature in the above range, and in the reaction injection molding, the initial viscosity of the composition in the mold can be well controlled. When the glass transition temperature of the polyol compound is outside the above range, an initial reaction may occur excessively and may be prematurely cured, and accordingly, the transparent resin layer may exhibit non-uniform physical properties, and there may be a problem that the electromagnetic wave transmittance is lowered.

The transparent resin layer includes a polyol compound having a glass transition temperature in the above range, while maintaining the function of the electromagnetic wave transmission cover, the transparent resin layer can exhibit uniform and excellent hardness and self-recovery throughout.

The subject may further include one additive selected from the group consisting of catalysts, leveling agents, antioxidants, UV absorbers and combinations thereof. For example, the subject is about 90% to about 95% by weight of the polyol compound, about 0.1% to about 3% by weight of a catalyst, about 0.1% to about 3% by weight of a leveling agent, about 0.1% of an antioxidant % To about 3% by weight, and about 1% to about 20% by weight of the UV absorber.

The subject may include a tin-based catalyst as a catalyst, and the curing temperature and time of the reaction injection molding may be optimized by including the catalyst in a content in the above range.

The composition includes a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule, together with the above subject comprising a polyol compound having three hydroxy groups, and can simultaneously impart excellent hardness and self-recovery while being transparent.

The above subject comprising a polyol compound having three hydroxy groups can form a network structure by three-dimensional crosslinking reaction with a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule. Accordingly, the transparent resin layer can simultaneously impart excellent hardness and self-recovery while being transparent. 3D crosslinking refers to a complete chemical bond such as a covalent bond or an ionic bond between molecules.

The isocyanate compound may be an aliphatic compound. In general, the hydrocarbon compound is divided into an aromatic compound and an aliphatic compound in which carbon compounds are linear, branched, and cyclic. At this time, the isocyanate compound may not include an aromatic isocyanate compound. In the above composition, when the isocyanate compound is an aromatic isocyanate compound, for example, toluene diisocyanate, benzyl groups are easily decomposed by heat and ultraviolet rays, and yellowing may occur. Accordingly, the metallic luster is not well recognized from the outside of the vehicle, and there may be a problem that design is deteriorated.

The isocyanate compound may include one selected from the group consisting of hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), and combinations thereof. For example, the isocyanate compound may be hexamethylene diisocyanate having two isocyanate groups.

The composition comprises the above subject comprising a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule; wherein the transparent resin layer comprises a urethane-based compound in which the polyol compound and the isocyanate compound are formed by a three-dimensional crosslinking reaction. It may include.

At this time, the subject may have a viscosity of about 60 cps to about 100 cps at 80°C. The viscosity can be measured, for example, using a Brookfield viscometer. The subject comprising the polyol compound having the three hydroxy groups has a viscosity in the above range, it is well mixed with the curing agent, it can exhibit excellent hardness and wear resistance.

The curing agent may have a viscosity of about 300 cps to about 400 cps at 80°C.

The viscosity can be adjusted by the molecular weight of the compound contained in the subject and the curing agent, the number of functional groups, the glass transition temperature and content.

The transparent resin layer may control the crosslink density, the length of the main chain, the hardness, etc. by mixing a subject having a viscosity in the above range and a curing agent having a viscosity in the above range. The crosslinking density refers to the ratio of the number of crosslinking points to the total number of constituent units of the urethane-based compound in the transparent resin layer.

The transparent resin layer may exhibit excellent transparency by mixing a subject having a viscosity in the above range and a curing agent, while exhibiting excellent hardness and wear resistance, and excellent self-recovery. For example, when the main agent and the curing agent include a low molecular weight compound and the viscosity is less than the above range, hardness may be weakened and wear resistance may be lowered. In addition, when the viscosity exceeds the above range, including a high molecular weight compound, the hardness may be increased, but the mixing efficiency of the main agent and the curing agent is poorly cured and the desired properties cannot be obtained.

The electromagnetic wave transmission cover is manufactured by reaction in molding (RIM) at about 60° C. to about 90° C., as described below, and includes the subject and the curing agent having a viscosity in the above range at 80° C. Can be mixed. And, as it is mixed with the viscosity in the above range, it can be well injected at a constant rate while constantly adjusting the initial viscosity in the mold. For example, if the viscosity and speed of the composition injected into the mold are not controlled, there may be a problem that an initial reaction occurs excessively and premature curing occurs.

In particular, the transparent resin layer of the electromagnetic wave transmission cover has a thickness of about 0.1 mm to about 10 mm, and the viscosity and injection rate of the composition are important in in-mold injection molding. The electromagnetic wave transmission cover may simultaneously impart excellent transparency and hardness and self-restorability to a transparent resin layer having a thickness of about 0.1 mm to about 10 mm by mixing a subject having a viscosity in the above range and a curing agent.

The weight ratio of the subject to the curing agent may be from about 1:1.5 to about 1:3. In addition, the composition comprising the subject and the curing agent may include the hydroxyl group (OH) to the isocyanate group (NCO) in an equivalent ratio of about 1:1 to about 1: 1.5. For example, it may be included in an equivalent ratio of about 1:1.3 to about 1:1.5.

The transparent resin layer adjusts the weight ratio of the main subject and the curing agent and the equivalent ratio of the hydroxy group (OH) to the isocyanate group (NCO) contained in the composition to the above range, thereby adhering power to the metal composite film layer and the base layer It can improve, while exhibiting excellent hardness and excellent self-recovery at the same time while maintaining transparency. For example, when the weight ratio of the subject and the equivalent ratio of the hydroxy group are less than the above ranges, adhesion between the metal composite film layer and the base layer is lowered, and side reactions may occur. And, the isocyanate may react with moisture in the air instead of the polyol to produce a low molecular substance, and accordingly, the hardness and strength of the transparent resin layer may be lowered. When the weight ratio of the subject and the equivalent ratio of the hydroxy group exceeds the above range, tacky properties may increase, and hardness and self-recovery may deteriorate.

The transparent resin layer is a subject containing a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule. As a cured product of the composition comprising, it may have a pencil hardness of 6H to 7H. The transparent resin layer may exhibit excellent self-restoring properties and pencil hardness in the above range by adjusting the viscosity, equivalent weight ratio, weight ratio, and the like of the subject and the curing agent.

Accordingly, the electromagnetic wave transmission cover including the transparent resin layer on the outermost side is prevented from being scratched or cracked on the surface due to mechanical, physical, and chemical influences, despite being exposed to the exterior of the vehicle along with the front grill. Restoration can maintain product quality.

Another embodiment of the invention is a subject comprising a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule; Preparing a first injection material comprising a metal composite film and a base layer; Including the step of putting the first injection material into a mold, adding a composition containing the subject and the curing agent, and curing to prepare a second injection material including a transparent resin layer, wherein the pencil hardness of the transparent resin layer is It provides a method for manufacturing an electromagnetic wave transmission cover of 6H to 7H.

The manufacturing method of the electromagnetic wave transmission cover can easily produce an electromagnetic wave transmission cover having excellent hardness and self-recovery at the same time without impairing the function of the electromagnetic wave transmission cover. In addition, it is possible to impart cost competitiveness by lowering the curing temperature and shortening the time.

First, the method for manufacturing the electromagnetic wave transmission cover includes a subject comprising a polyol compound having three hydroxyl groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule; respectively. The composition is a two-component type, and the main subject and the curing agent are prepared and stored separately. The subject matter, curing agent, and composition are as described above.

Then, a first injection material including a metal composite film and a base layer is prepared. The first injection material may be manufactured through a method of in-mold decoration or in-mold labeling.

The first injection material is placed in a mold, a composition containing the subject and the curing agent is introduced, and cured to produce a second injection material including a transparent resin layer, including a transparent resin layer, a metal composite film layer and a base layer The electromagnetic wave transmission cover can be manufactured.

Specifically, the subject and the curing agent are blended in a predetermined amount in a mixer to form a composition. For example, the subject has a viscosity of about 60 cps to about 100 cps at 80° C., and the curing agent has a viscosity of about 300 cps to about 400 cps at 80° C., wherein the subject to the curing agent is about 1: 1.5. To about 1:3 by weight. And, the composition comprising the subject and the curing agent may be formulated to include the hydroxyl group (OH) to the isocyanate group (NCO) in an equivalent ratio of about 1:1 to about 1: 1.5. For example, it may be included in an equivalent ratio of about 1:1.3 to about 1:1.5. Accordingly, the transparent resin layer can simultaneously exhibit excellent hardness and self-recovery while maintaining transparency.

Then, the composition may be injected onto the metal composite film layer of the first injection material in a mold, and cured to form a second injection material including a transparent resin layer. The second injection material includes the transparent resin layer, the metal composite film and the base layer.

The mold is heated to a temperature of about 60°C to about 90°C, and the transparent resin layer may be formed by curing at about 60°C to about 90°C for 5 seconds to 20 seconds.

In general, the electromagnetic wave transmission cover is manufactured by in-mold injection molding, and since a high temperature composition is injected at high temperature during each layer production, an additional process such as a heat-resistant tape must be attached to protect the metal composite film layer. There is a cumbersome and expensive problem.

The electromagnetic wave transmission cover is injected at a temperature of about 60°C to about 90°C, and may not damage the metal composite film without attaching a separate heat-resistant tape. Accordingly, it is possible to simplify the process and provide cost competitiveness while maintaining the function of the electromagnetic wave transmission cover.

The method of manufacturing the electromagnetic wave transmission cover that is injected from a mold having a temperature of about 60°C to about 90°C can be mixed well by including the subject and the curing agent having a viscosity in the aforementioned range at 80°C. And, as it is mixed with the viscosity in the above range, it can be well injected at a constant rate while constantly adjusting the initial viscosity in the mold at the temperature. For example, if the viscosity and speed of the composition injected into the mold are not controlled, there may be a problem that an initial reaction occurs excessively and premature curing occurs.

In particular, the transparent resin layer of the electromagnetic wave transmission cover manufactured by the above manufacturing method may have a thickness of about 0.1 mm to about 10 mm. In addition, the diameter of the injection hole in the mold into which the composition is injected may have about 5 mm to about 10 mm. Therefore, in the method of manufacturing the electromagnetic wave transmission cover, the viscosity and the injection rate of the composition can be controlled by adjusting the viscosity and the blending amount of the subject and the curing agent, and accordingly, the crosslinking density and the degree of curing are controlled to control the 3 of the transparent resin layer. The dimensional crosslinking structure can be adjusted. Accordingly, it is possible to improve the adhesion between the metal composite film layer and the base layer, and to provide an electromagnetic wave transmission cover including a transparent resin layer that simultaneously exhibits excellent hardness and excellent self-recovery while maintaining transparency.

The composition comprising the subject and the curing agent may be cured at about 60°C to about 90°C for about 5 seconds to about 20 seconds to form the second injection. The method for manufacturing the electromagnetic wave transmission cover can form a cured product within a short time in the range at a low temperature in the range, thereby providing cost competitiveness. The composition may optimize the curing temperature and time by controlling the content of the catalyst included in the subject.

The electromagnetic wave transmission cover has a pencil hardness of about 6H to about 7H, while maintaining transparency and excellent self-recovery, despite being exposed to the exterior of the vehicle with the front grill, scratching of the surface due to mechanical, physical, and chemical effects It prevents cracking and can be easily restored to maintain product quality.

(Example)

Example 1:

A polyether polyol compound having three hydroxy groups (Tg: 75°C), a catalyst, a leveling agent, an antioxidant and a UV absorber, at 80°C, a subject having a viscosity of about 90 cps; And hexamethylene diisocyanate, and at 80° C., a curing agent having a viscosity of about 380 cps; each prepared and stored in a container.

A metal composite film formed by depositing indium is placed in a primary mold, and acrylonitrile styrene acrylate (ASA) is injected into the primary mold to include a metal composite film layer and a base layer A first injection product was prepared.

The first injection material was placed in a second mold, and a composition in which the subject and the curing agent were uniformly blended in a mixer was injected onto the metal composite film layer of the first injection material. At this time, the main agent to the curing agent was formulated in a weight ratio of 1: 2.8, and the composition was made to include the hydroxy group (OH) to the isocyanate group (NCO) in an equivalent ratio of 1: 1.3.

Then, in the second mold, the composition was cured at 90° C. for 20 seconds to prepare a second injection material comprising a transparent resin layer having a thickness of 1 mm, and transmitting electromagnetic waves including a transparent resin layer, a metal composite film layer, and a base layer. A cover was prepared.

Comparative Example 1:

A metal composite film formed by depositing indium is placed in a primary mold, and an acrylonitrile styrene acrylate (ASA) is injected to prepare a first injection material including a metal composite film layer and a base layer Did.

The first injection material was placed in a second mold, and polycarbonate (PC) melted at 290° C. was injected onto the metal composite film layer of the first injection material. And, by curing in a second mold at a temperature of 80 ℃ for 60 seconds to prepare a second injection material containing a polycarbonate transparent resin layer.

Then, a hard coating solution containing an acrylic resin was sprayed on the transparent resin layer with a spray, and UV cured to form a hard coating layer. Accordingly, an electromagnetic wave transmission cover including a hard coating layer, a polycarbonate transparent resin layer, a metal composite film layer, and a substrate layer was prepared.

Comparative Example 2:

A polyether polyol compound having two hydroxy groups (Tg: 65°C), a catalyst, a leveling agent, an antioxidant, and a UV absorber, and at 80°C, a subject having a viscosity of about 150 cps; And hexamethylene diisocyanate, and at 80° C., a curing agent having a viscosity of about 500 cps; an electromagnetic wave transmission cover was prepared in the same manner as in Example 1, except that each was prepared.

evaluation

Experimental Example 1: Pencil hardness

The pencil hardness of the transparent resin layer of the above-mentioned examples and comparative examples of the electromagnetic wave transmission cover was measured according to JISK5600-5-4, and the pencil hardness standard was a Mitsubishi pencil (Mitsubishi 6B to 9H (17), electric 0.75kg). Load basis) and the results are shown in Table 1 below.

Experimental Example 2: Self-Resilience

After scratching the transparent resin layer of the electromagnetic wave transmission cover in the above Examples and Comparative Examples three times against the surface of the wire brush, scratches occurred on the surface of the transparent resin layer. It is checked with the naked eye, and the time taken to restore the original state of the transparent resin layer is measured by using a timer as the scratch of the transparent resin layer disappears at room temperature. The results are shown in Table 1 below .

Experimental Example 3: Haze (%)

The haze of the transparent resin layer of the examples and comparative examples of the electromagnetic wave transmission cover was measured using a Spectrophotometer (Konica Minolta, CM-5) by a measuring method according to ASTM JIS K7105. And the results are shown in Table 1 below.

Pencil hardness Self-Resilience (min) Haze (%) Example 1 6H One 0.6 Comparative Example 1 2H none 0.5 Comparative Example 2 H 30 0.8

As shown in Table 1, it can be seen that the example shows excellent transparency with a hardness of 6H or more and a low haze value while the scratch of the transparent resin layer disappears in 1 minute. On the other hand, in the case of Comparative Example 1, the scratch does not disappear and the hardness is too low to 2H, in the case of Comparative Example 2, the hardness is low to H, and the scratch disappears after 30 minutes. Able to know.

Although described in the present invention as described above, the present invention is not limited by the embodiments disclosed herein, and it is obvious that various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. In addition, although the operation and effect according to the configuration of the present invention has not been explicitly described while explaining the embodiments of the present invention, it is natural that the predictable effect by the configuration should also be recognized.

Claims (10)

It includes a transparent resin layer, a metal composite film layer and a base layer,
The transparent resin layer is a subject containing a polyol compound having three hydroxy groups; And a curing agent comprising an isocyanate compound having at least two isocyanate groups per molecule;
Pencil hardness of the transparent resin layer is 6H to 7H
Electromagnetic wave transmission cover.
According to claim 1,
The glass transition temperature of the polyol compound is 70 ℃ to 80 ℃
Electromagnetic wave transmission cover.
According to claim 1,
At 80°C, the viscosity of the subject is 60 cps to 100 cps
Electromagnetic wave transmission cover.
According to claim 1,
The subject further comprises one additive selected from the group consisting of catalysts, leveling agents, antioxidants, UV absorbers and combinations thereof.
Electromagnetic wave transmission cover.
According to claim 1,
The isocyanate compound is an aliphatic compound
Electromagnetic wave transmission cover.
According to claim 1,
At 80°C, the viscosity of the curing agent is 300 cps to 400 cps
Electromagnetic wave transmission cover.
According to claim 1,
The weight ratio of the subject to the curing agent is 1:1.5 to 1:3
Electromagnetic wave transmission cover.
According to claim 1,
The composition comprises the hydroxy group (OH) to the isocyanate group (NCO) in an equivalent ratio of 1:1 to 1: 1.5
Electromagnetic wave transmission cover.
Preparing a curing agent comprising a subject comprising a polyol compound having three hydroxy groups and an isocyanate compound having at least two isocyanate groups per molecule, respectively;
Preparing a first injection material comprising a metal composite film and a base layer;
Including the step of preparing the second injection material comprising a transparent resin layer by putting the first injection material into a mold, introducing a composition containing the subject and the curing agent, and curing the composition.
Pencil hardness of the transparent resin layer is 6H to 7H
Method for manufacturing an electromagnetic wave transmission cover.
The method of claim 9,
The transparent resin layer is cured at 60 ℃ to 90 ℃ for 5 seconds to 20 seconds
Method for manufacturing an electromagnetic wave transmission cover.