KR100193184B1 - Navigation system monitor case with electromagnetic shielding - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation system monitor case, in which a monitor generates electromagnetic waves like other electronic devices, and is known to cause various diseases in a human body when a driver is exposed to electromagnetic waves for a long time.

Accordingly, the present invention can provide an navigation system monitor case coated with an electromagnetic wave shielding material made of polyaniline added with silver, thereby bringing about an effect of shielding electromagnetic waves at about 44 dB to 49 dB within a frequency range of about 10 MHz to 1 GHz.

Description

Navigation system monitor case with electromagnetic shielding function.

The present invention relates to a case for shielding electromagnetic waves generated from a navigation system monitor of a vehicle, and more particularly, to shield electromagnetic waves made of a conductive polymer in a monitor case so as to have a shielding efficiency of 44 dB to 49 dB in a frequency band of 1 MHz to 1 GHz. A monitor case of a navigation system coated with a material.

The navigation system of a vehicle is a device that enables a driver to receive information on road traffic conditions, geographic location, and time required by using the navigation system of an aircraft by using a wireless communication network inside the vehicle. At present, R & D is actively underway.

Among these navigation systems, the monitor is generally installed at the front of the vehicle so that the driver can see sufficiently even when looking ahead.

By the way, such a monitor generates electromagnetic waves like other electronic devices, it is found that causes a variety of diseases in the human body when the driver is exposed to electromagnetic waves over a long period of time.

Such electromagnetic waves are generated by periodic changes in electric fields or magnetic fields, and are waves that propagate in space at light speed, and cause electromagnetic interference (EMI) of drivers and passengers due to electromagnetic waves generated by the above-described navigation system monitor. There is a need for a solution to solve the problem.

Conventionally, as a method for blocking such electromagnetic waves, a case is proposed in which the case is made of aluminum material having excellent electromagnetic shielding effect and strong environmental resistance, but this is expensive in processing cost and material cost, unstable in sealing state, and heavy in weight. Due to various negative factors that require post-processing, they have not been put to practical use.

In addition, as an alternative to shielding the electromagnetic waves, polyamides, ferrite mixtures, Cu mesh fabrics, carbon mesh fabrics, conductive materials using magnetic materials having very high permeability or containing carbon and lead (pb) tapes. A method of applying a (conductive) fabric, amorphous ribbon, carbon powder, rubber with Zn, Sus powder, or polymer with Cu, Ni, etc. to a navigation system monitor case is used.

Here, the electromagnetic wave shielding materials as described above are mostly manufactured to have conductivity by adding a conductive material in the form of a powder to give conductivity to the non-conductive material.

That is, non-conductive materials such as polyamides, polymers, rubbers, or fabrics are made of conductors by the addition of conductive metal materials such as Cu, Ni, It consists of materials such as C, Zn, Sus, or pb.

However, as described above, when the conductive powder or metal added to impart conductivity to the nonconductive material is added in a predetermined amount or more, the mechanical stress of the finally produced electromagnetic shielding material is weakened, and the added conductive material is vision The electromagnetic shielding material applied on the surface of the case in the case of not being evenly distributed in the conductive material causes an increased imbalance of conductivity.

The present invention has been made in order to solve the above-mentioned conventional problems, it is not necessary to add a conductive material to increase the manufacturing cost, to provide a navigation system monitor case coated with an electromagnetic shielding material that does not weaken mechanical stress There is a gold purpose.

The present invention for realizing such an object is characterized by coating an electromagnetic wave shielding material in which silver is added to polyaniline on a navigation system monitor case.

1 is a schematic diagram illustrating a system for measuring electromagnetic shielding effects in accordance with the present invention.

Figure 2 is a graph showing the electromagnetic shielding effect of the electromagnetic shielding material is added silver according to the present invention.

Explanation of symbols for the main parts of the drawings

Signal generator 2. Spectrum analyzer

Electromagnetic shielding material 4. Calculator

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a system for measuring the electromagnetic shielding effect, Figure 2 is a graph showing the shielding effect of the electromagnetic shielding material according to the present invention.

Conductive polymers such as polyaniline according to the present invention can be easily mixed with a coating material as an organic material itself, excellent in flexibility and processability, etc., and are a material used for the purpose as a new conductor, a thin display device or an antistatic material.

The polyaniline has a wide range of electrical conductivity from the semiconductor region to the conductor region, and only three of the four electrons involved in the bonding of carbon contribute to the molecular bond as sigma bond (σ-bond), and the remaining 1 Electrons are unsaturated and have a sp ₂ molecular orbital which forms? Energy bands.

In addition, according to the structure of the π-conjugation (conjugation) and the delocalized electrons after doping, which are widely spread along the polymer backbone, they are classified into reducing type, intermediate oxidation type, and oxidation type. And physical properties can be obtained in various ways.

On the other hand, the conduction of the conductive polymer can be largely interpreted by two theories, and the soliton theory, polyaniline and polythiophene represented by polypyrrole and polyacetylene. An example is the polaron theory.

First, in isolated wave theory, isolated wave refers to a structural defect in a chain such as polypyrrole, and has a degenerate ground state in which polypyrrole chains on the left and right of the structural defect are symmetrically.

Such structural defects of the conductive polymer exist in three kinds of neutral, positive and negative soliton, and when the charge is charged, the spin becomes zero and when the charge is zero, it becomes 1/2.

That is, the concept contrary to the phenomenon in which the charged particles are found in ordinary electrons or protons, or the electrical conductivity occurs because these charged solitones exist in the chain.

In addition, in the case of polyaline, in the case of polyaniline, the arrangement of molecules on the left and right sides of the structural defect is asymmetric, resulting in a non-degenerate ground state whose energy states are not identical. Bipolarons are formed by pairing two polarons.

In other words, the destructive state in the conductive polymer chain degenerates from the deflated isolation plate level, resulting in level splitting of the energy levels, thereby forming conductivity by forming the polaron and bipolaron levels.

The polyaniline powder having such characteristics is slowly added to 30 ml of NMP solution, and then a small amount of silver is added and stirred well. The solution was cleaned and poured on a horizontally controlled polymer fabric and dried in a convection oven maintained at about 60 ° C. for about 15 hours to prepare a polyaniline thin film coated with carbon black. You can get it.

Herein, the polyaniline and silver (Ag) mixing ratio is preferably 2.5: 2.0g in weight ratio (wt%) as a result of the experiment.

A graph measuring the electromagnetic wave shielding efficiency of the polyaniline thin film to which silver is added to have such a mixing ratio is shown in FIG. 2.

The measurement method was performed by the standard test method (ASTM D 4935-89) of the electromagnetic shielding effect of the American Society of Testing and Materials (ASTM), and the measurement error is ± 3dB.

That is, as shown in FIG. 1, the electromagnetic wave shielding material 3 between the signal generator 1 for generating electromagnetic waves and the spectrum analyzer 2 for receiving and analyzing the electromagnetic waves generated from the signal generator 1. (Electromagnetic wave shielding efficiency SE) by the shielding material (3) in the state that is placed through the shielding material (3) with respect to the incident power (P ₁ ) incident on the shielding material (3) The received power P ₂ received by the spectrum analyzer 2 is represented by the ratio represented by Equation 1 below.

SE (dB) = 10log (P ₁ / P ₂ )

In this case, the electromagnetic shielding effect (SE) in the far-field region where the distance between the radiated electromagnetic wave source and the specimen is larger than λ / 2π is achieved by means of a measurement system consisting of a flanged coaxial transmission line. It is predicted by measuring the incident power, reflected power and transmission power in the calculator 4 through.

The electromagnetic shielding effect of the silver-added polyaniline according to the present invention as measured by the flange-type coaxial transmission line as described above is shown in a graph in Figure 2, as shown in the range of about 44dB to about 10MHz to 1GHz It can be expected that the electromagnetic wave can be shielded by about 49 dB.

Therefore, when the polyaniline electromagnetic wave shielding material containing silver is coated on the polymer-based fabric, the adhesive strength is excellent because the fabric and the electromagnetic shielding material are the same polymer series, and the cost of the conductive polymer is lower than that of metals, thereby reducing the cost. Can bring

Thus, the navigation device monitor case coated with the electromagnetic shielding material can block the electromagnetic waves generated from the monitor, preventing the driver and passengers from imbalance of body rhythm caused by harmful electromagnetic waves, and minimize the obstacles such as helplessness and fatigue caused by the electromagnetic waves. The effect can be obtained.

The foregoing is merely illustrative of a preferred embodiment of the present invention and those skilled in the art to which the present invention pertains may make modifications and changes to the present invention without changing the subject matter of the present invention.

Therefore, according to the present invention, the electromagnetic wave shielding material made of polyaniline added with silver can be coated on the navigation device monitor case, thereby improving the electromagnetic wave shielding efficiency, improving the adhesive force, and reducing the cost.

Claims (2)

The polyaniline powder was slowly added to 30 ml of NMP solution, and then a small amount of silver was added to the mixture, followed by stirring. Then, the polyaniline powder was poured on a fabric of a horizontally controlled polymer material, and then poured into a convection oven maintained at about 60 ° C. Navigation system monitor case with electromagnetic shielding function manufactured by drying about time. The method of claim 1, The navigation system monitor case having an electromagnetic shielding function, wherein the polyaniline and silver (Ag) are mixed at a weight ratio (wt%) of 2.5: 2.0 g.